BACK TO INDEX BACK TO OTHMAR FREY'S HOMEPAGE Publications of year 2003 Thesis
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| Abstract: | This thesis contains a description of SAS processing algorithms, offering improvements in Fourier-based reconstruction, motion-compensation, and autofocus. Fourier-based image reconstruction is reviewed and improvements shown as the result of improved system modelling. A number of new algorithms based on the wavenumber algorithm for correcting second order effects are proposed. In addition, a new framework for describing multiple-receiver reconstruction in terms of the bistatic geometry is presented and is a useful aid to understanding. Motion-compensation techniques for allowing Fourier-based reconstruction in widebeam geometries suffering large-motion errors are discussed. A motion-compensation algorithm exploiting multiple receiver geometries is suggested and shown to provide substantial improvement in image quality. New motion compensation techniques for yaw correction using the wavenumber algorithm are discussed. A common framework for describing phase estimation is presented and techniques from a number of fields are reviewed within this framework. In addition a new proof is provided outlining the relationship between eigenvector-based autofocus phase estimation kernels and the phase-closure techniques used astronomical imaging. Micronavigation techniques are reviewed and extensions to the shear average single-receiver micronavigation technique result in a 3-4 fold performance improvement when operating on high-contrast images. The stripmap phase gradient autofocus (SPGA) algorithm is developed and extends spotlight SAR PGA to the wide-beam, wide-band stripmap geometries common in SAS imaging. SPGA supersedes traditional PGA-based stripmap autofocus algorithms such as mPGA and PCA -- the relationships between SPGA and these algorithms is discussed. SPGA's operation is verified on simulated and field-collected data where it provides significant image improvement. SPGA with phase-curvature based estimation is shown and found to perform poorly compared with phase-gradient techniques. The operation of SPGA on data collected from Sydney Harbour is shown with SPGA able to improve resolution to near the diffraction-limit. Additional analysis of practical stripmap autofocus operation in presence of undersampling and space-invariant blurring is presented with significant comment regarding the difficulties inherent in autofocusing field-collected data. Field-collected data from trials in Sydney Harbour is presented along with associated autofocus results from a number of algorithms. |
@PhdThesis{Callow2003PhD:PGAforSAS,
Title = {{Signal Processing for Synthetic Aperture Sonar Image Enhancement}},
Author = {Hayden J. Callow},
Url = {http://www.elec.canterbury.ac.nz/research/acoustics/pubs/theses/Callow_thesis_2003.pdf},
Year = {2003},
Abstract = {This thesis contains a description of SAS processing algorithms, offering improvements in Fourier-based reconstruction, motion-compensation, and autofocus. Fourier-based image reconstruction is reviewed and improvements shown as the result of improved system modelling. A number of new algorithms based on the wavenumber algorithm for correcting second order effects are proposed. In addition, a new framework for describing multiple-receiver reconstruction in terms of the bistatic geometry is presented and is a useful aid to understanding. Motion-compensation techniques for allowing Fourier-based reconstruction in widebeam geometries suffering large-motion errors are discussed. A motion-compensation algorithm exploiting multiple receiver geometries is suggested and shown to provide substantial improvement in image quality. New motion compensation techniques for yaw correction using the wavenumber algorithm are discussed. A common framework for describing phase estimation is presented and techniques from a number of fields are reviewed within this framework. In addition a new proof is provided outlining the relationship between eigenvector-based autofocus phase estimation kernels and the phase-closure techniques used astronomical imaging. Micronavigation techniques are reviewed and extensions to the shear average single-receiver micronavigation technique result in a 3-4 fold performance improvement when operating on high-contrast images. The stripmap phase gradient autofocus (SPGA) algorithm is developed and extends spotlight SAR PGA to the wide-beam, wide-band stripmap geometries common in SAS imaging. SPGA supersedes traditional PGA-based stripmap autofocus algorithms such as mPGA and PCA -- the relationships between SPGA and these algorithms is discussed. SPGA's operation is verified on simulated and field-collected data where it provides significant image improvement. SPGA with phase-curvature based estimation is shown and found to perform poorly compared with phase-gradient techniques. The operation of SPGA on data collected from Sydney Harbour is shown with SPGA able to improve resolution to near the diffraction-limit. Additional analysis of practical stripmap autofocus operation in presence of undersampling and space-invariant blurring is presented with significant comment regarding the difficulties inherent in autofocusing field-collected data. Field-collected data from trials in Sydney Harbour is presented along with associated autofocus results from a number of algorithms.},
Keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus, Stripmap, Stripmap PGA, Stripmap Phase Gradient Autofocus, SAS, Synthetic Aperture Sonar},
Pdf = {../../../docs/Callow2003PhD.pdf},
School = {University of Canterbury}
}
Articles in journal or book chapters
-
V. Alberga and M. Chandra.
Volume decorrelation resolution in polarimetric SAR interferometry.
Electronics Letters,
39(3):314-315,
February 2003.
Keyword(s): buildings,
distributed scatterer height,
forests,
interferometric coherence images,
man-made artifacts,
polarimetric SAR data,
polarimetric SAR interferometry,
random volumes,
stationary distributed targets,
synthetic aperture radar,
volume decorrelation resolution,
decorrelation,
radar imaging,
radar polarimetry,
radiowave interferometry,
synthetic aperture radar,
target tracking;.
Abstract: Volume decorrelation is a phenomenon affecting the synthetic aperture radar (SAR) interferometric coherence images in the presence of forests or buildings. 'Resolving' this effect could lead to an estimation of the height of the observed distributed scatterers. An empirical method is suggested to distinguish volume decorrelation due to random volumes (such as trees) and stationary distributed targets (such as man-made artifacts) when polarimetric SAR data are used. @Article{1179472, author = {Alberga, V. and Chandra, M.}, journal = {Electronics Letters}, title = {Volume decorrelation resolution in polarimetric SAR interferometry}, year = {2003}, issn = {0013-5194}, month = feb, number = {3}, pages = {314-315}, volume = {39}, abstract = {Volume decorrelation is a phenomenon affecting the synthetic aperture radar (SAR) interferometric coherence images in the presence of forests or buildings. 'Resolving' this effect could lead to an estimation of the height of the observed distributed scatterers. An empirical method is suggested to distinguish volume decorrelation due to random volumes (such as trees) and stationary distributed targets (such as man-made artifacts) when polarimetric SAR data are used.}, doi = {10.1049/el:20030236}, keywords = {buildings; distributed scatterer height; forests; interferometric coherence images; man-made artifacts; polarimetric SAR data; polarimetric SAR interferometry; random volumes; stationary distributed targets; synthetic aperture radar; volume decorrelation resolution; decorrelation; radar imaging; radar polarimetry; radiowave interferometry; synthetic aperture radar; target tracking;}, } -
I. Baran,
M. P. Stewart,
B. M. Kampes,
Z. Perski,
and P. Lilly.
A modification to the Goldstein radar interferogram filter.
IEEE Transactions on Geoscience and Remote Sensing,
41(9):2114-2118,
Sep. 2003.
Keyword(s): radar theory,
radiowave interferometry,
synthetic aperture radar,
Goldstein radar interferogram filter modification,
adaptive Goldstein radar interferogram filter,
radar interferometry products,
synthetic aperture radar,
SAR,
phase filtering,
phase statistics,
coherence,
incoherent areas,
coherent areas,
loss of signal,
noise level reduction,
Adaptive filters,
Filtering,
Australia,
Radar interferometry,
Noise reduction,
Monitoring,
Decorrelation,
Noise level,
Statistics,
Synthetic aperture radar.
Abstract: We present a modification to the adaptive Goldstein radar interferogram filter which improves the quality of interferometry products. The proposed approach makes the Goldstein filter parameter alpha dependent on coherence, such that incoherent areas are filtered more than coherent areas. This modification minimizes loss of signal while still reducing the level of noise. @Article{baranStewartKampesPerskiLillyTGRS2003ModifiedGoldsteinWernerInSARFilter, author = {I. {Baran} and M. P. {Stewart} and B. M. {Kampes} and Z. {Perski} and P. {Lilly}}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, title = {A modification to the Goldstein radar interferogram filter}, year = {2003}, issn = {1558-0644}, month = {Sep.}, number = {9}, pages = {2114-2118}, volume = {41}, abstract = {We present a modification to the adaptive Goldstein radar interferogram filter which improves the quality of interferometry products. The proposed approach makes the Goldstein filter parameter alpha dependent on coherence, such that incoherent areas are filtered more than coherent areas. This modification minimizes loss of signal while still reducing the level of noise.}, doi = {10.1109/TGRS.2003.817212}, file = {:baranStewartKampesPerskiLillyTGRS2003ModifiedGoldsteinWernerInSARFilter.pdf:PDF}, keywords = {radar theory;radiowave interferometry;synthetic aperture radar;Goldstein radar interferogram filter modification;adaptive Goldstein radar interferogram filter;radar interferometry products;synthetic aperture radar;SAR;phase filtering;phase statistics;coherence;incoherent areas;coherent areas;loss of signal;noise level reduction;Adaptive filters;Filtering;Australia;Radar interferometry;Noise reduction;Monitoring;Decorrelation;Noise level;Statistics;Synthetic aperture radar}, } -
Silvia Cimmino,
Giorgio Franceschetti,
Antonio Iodice,
Daniele Riccio,
and Giuseppe Ruello.
Efficient Spotlight SAR Raw Signal Simulation of Extended Scenes.
IEEE Transactions on Geoscience and Remote Sensing,
41(10):2329-2337,
October 2003.
Keyword(s): SAR Processing,
Simulation,
SAR Simulator,
Raw Data Simulator,
Spotlight SAR.
Abstract: Synthetic aperture radar (SAR) raw signal simulation is a powerful tool for designing new sensors, testing processing algorithms, planning missions, and devising inversion algorithms. In this paper, a spotlight SAR raw signal simulator for distributed targets is presented. The proposed procedure is based on a Fourier domain analysis: a proper analytical reformulation of the spotlight SAR raw signal expression is presented. It is shown that this reformulation allows us to design a very efficient simulation scheme that employs fast Fourier transform codes. Accordingly, the computational load is dramatically reduced with respect to a time-domain simulation and this, for the first time, makes spotlight simulation of extended scenes feasible. @Article{CimFrancesIodiceRiccio03:Simulation, Title = {{Efficient Spotlight SAR Raw Signal Simulation of Extended Scenes}}, Author = {Silvia Cimmino and Giorgio Franceschetti and Antonio Iodice and Daniele Riccio and Giuseppe Ruello}, Month = Oct, Number = {10}, Pages = {2329-2337}, Url = {http://ieeexplore.ieee.org/iel5/36/27742/01237398.pdf}, Volume = {41}, Year = {2003}, Abstract = {Synthetic aperture radar (SAR) raw signal simulation is a powerful tool for designing new sensors, testing processing algorithms, planning missions, and devising inversion algorithms. In this paper, a spotlight SAR raw signal simulator for distributed targets is presented. The proposed procedure is based on a Fourier domain analysis: a proper analytical reformulation of the spotlight SAR raw signal expression is presented. It is shown that this reformulation allows us to design a very efficient simulation scheme that employs fast Fourier transform codes. Accordingly, the computational load is dramatically reduced with respect to a time-domain simulation and this, for the first time, makes spotlight simulation of extended scenes feasible.}, Journal = {IEEE Transactions on Geoscience and Remote Sensing}, Keywords = {SAR Processing, Simulation, SAR Simulator, Raw Data Simulator, Spotlight SAR}, Pdf = {../../../docs/CimFrancesIodiceRiccio03.pdf} } -
C. Colesanti,
A. Ferretti,
F. Novali,
C. Prati,
and F. Rocca.
SAR monitoring of progressive and seasonal ground deformation using the permanent scatterers technique.
IEEE Trans. Geosci. Remote Sens.,
41(7):1685-1701,
July 2003.
Keyword(s): SAR Processing,
Persistent Scatterer Interferometry,
PSI,
California,
Fremont,
SAR,
San Jose,
Santa Clara Valley,
Southern Bay Area,
USA,
United States,
coseismic displacement,
differential radar interferometry,
geodesy,
geodetic deformation,
geophysical measurement technique,
land surface,
permanent scatterer,
phase decorrelation,
postseismic displacement,
progressive deformation,
radar remote sensing,
seasonal ground deformation,
spaceborne radar,
subsidence,
synthetic aperture radar,
terrain mapping,
geodesy,
geophysical techniques,
radar theory,
remote sensing by radar,
spaceborne radar,
synthetic aperture radar,
terrain mapping;.
Abstract: Spaceborne differential radar interferometry has proven a remarkable potential for mapping ground deformation phenomena (e.g., urban subsidence, volcano dynamics, coseismic and postseismic displacements along faults, as well as slope instability). However, a full operational capability has not been achieved yet due to atmospheric disturbances and phase decorrelation phenomena. These drawbacks can often be-at least partially-overcome by carrying out measurements on a subset of image pixels corresponding to natural or artificial stable reflectors (permanent scatterers (PS) ) and exploiting long temporal series of interferometric data. This approach allows one to push the measurement precision very close to its theoretical limit (in the order of sim;1 mm for C-band European Remote Sensing (ERS)-like sensors). In this paper, the detection of both time-uniform and seasonal deformation phenomena is addressed, and a first assessment of the precision achievable by means of the PS Technique is discussed. Results highlighting deformation phenomena occurring in two test sites in California are reported (Fremont in the Southern Bay Area and San Jose in the Santa Clara Valley). @Article{colesantiFerrettiNovaliPratiRocca2003, author = {Colesanti, C. and Ferretti, A. and Novali, F. and Prati, C. and Rocca, F.}, title = {{SAR} monitoring of progressive and seasonal ground deformation using the permanent scatterers technique}, journal = {IEEE Trans. Geosci. Remote Sens.}, year = {2003}, volume = {41}, number = {7}, pages = {1685-1701}, month = jul, issn = {0196-2892}, abstract = {Spaceborne differential radar interferometry has proven a remarkable potential for mapping ground deformation phenomena (e.g., urban subsidence, volcano dynamics, coseismic and postseismic displacements along faults, as well as slope instability). However, a full operational capability has not been achieved yet due to atmospheric disturbances and phase decorrelation phenomena. These drawbacks can often be-at least partially-overcome by carrying out measurements on a subset of image pixels corresponding to natural or artificial stable reflectors (permanent scatterers (PS) ) and exploiting long temporal series of interferometric data. This approach allows one to push the measurement precision very close to its theoretical limit (in the order of sim;1 mm for C-band European Remote Sensing (ERS)-like sensors). In this paper, the detection of both time-uniform and seasonal deformation phenomena is addressed, and a first assessment of the precision achievable by means of the PS Technique is discussed. Results highlighting deformation phenomena occurring in two test sites in California are reported (Fremont in the Southern Bay Area and San Jose in the Santa Clara Valley).}, doi = {10.1109/TGRS.2003.813278}, file = {:colesantiFerrettiNovaliPratiRocca2003.pdf:PDF}, keywords = {SAR Processing, Persistent Scatterer Interferometry, PSI, California; Fremont; SAR; San Jose; Santa Clara Valley; Southern Bay Area; USA; United States; coseismic displacement; differential radar interferometry; geodesy; geodetic deformation; geophysical measurement technique; land surface; permanent scatterer; phase decorrelation; postseismic displacement; progressive deformation; radar remote sensing; seasonal ground deformation; spaceborne radar; subsidence; synthetic aperture radar; terrain mapping; geodesy; geophysical techniques; radar theory; remote sensing by radar; spaceborne radar; synthetic aperture radar; terrain mapping;}, } -
F.M. Dickey,
L.A. Romero,
J.M. DeLaurentis,
and A.W. Doerry.
Super-resolution, degrees of freedom and synthetic aperture radar.
Radar, Sonar and Navigation, IEE Proceedings -,
150(6):419-429,
2003.
Keyword(s): SAR Processing,
SAR Tomography,
Tomography,
Fourier transforms,
eigenvalues and eigenfunctions,
extrapolation,
inverse problems,
mathematical operators,
radar imaging,
radar resolution,
synthetic aperture radar,
Fourier transform extrapolation,
SAR images,
degrees of freedom,
eigenvalue spectrum,
ill posed problem,
operator inversion problem,
super-resolution.
Abstract: Super-resolution concepts offer the potential of resolution beyond the classical limit. This great promise has not generally been realised. The potential application of super-resolution concepts to synthetic aperture radar is investigated. The analytical basis for super-resolution theory is discussed. The application of the concept to synthetic aperture radar is investigated as an operator inversion problem. Generally, the operator inversion problem is ill posed. However, it is shown that it is the particular form of the eigenvalue spectrum of the associated operator that precludes any significant resolution enhancement of synthetic aperture radar images. A criterion for judging super-resolution processing of an image is presented. @Article{dickeyRomeroDeLaurentisDoerry03:Tomo, author = {Dickey, F.M. and Romero, L.A. and DeLaurentis, J.M. and Doerry, A.W.}, journal = {Radar, Sonar and Navigation, IEE Proceedings -}, title = {Super-resolution, degrees of freedom and synthetic aperture radar}, year = {2003}, issn = {1350-2395}, number = {6}, pages = {419--429}, volume = {150}, abstract = {Super-resolution concepts offer the potential of resolution beyond the classical limit. This great promise has not generally been realised. The potential application of super-resolution concepts to synthetic aperture radar is investigated. The analytical basis for super-resolution theory is discussed. The application of the concept to synthetic aperture radar is investigated as an operator inversion problem. Generally, the operator inversion problem is ill posed. However, it is shown that it is the particular form of the eigenvalue spectrum of the associated operator that precludes any significant resolution enhancement of synthetic aperture radar images. A criterion for judging super-resolution processing of an image is presented.}, keywords = {SAR Processing, SAR Tomography, Tomography, Fourier transforms, eigenvalues and eigenfunctions, extrapolation, inverse problems, mathematical operators, radar imaging, radar resolution, synthetic aperture radar, Fourier transform extrapolation, SAR images, degrees of freedom, eigenvalue spectrum, ill posed problem, operator inversion problem, super-resolution}, owner = {ofrey}, pdf = {../../../docs/dickeyRomeroDelaurentisDoerryTomo03.pdf}, url = {http://ieeexplore.ieee.org/iel5/2198/28064/01254301.pdf}, } -
Fred M. Dickey,
Louis A. Romero,
and Armin W. Doerry.
Window functions for imaging radar: a maximum energy approach to contiguous and notched spectrums.
Optical Engineering,
42(7):2113-2128,
2003.
Keyword(s): SAR Processing,
radar imaging,
synthetic aperture radar,
sidelobes,
window functions,
filtering,
notched spectrum.
Abstract: Imaging systems such as synthetic aperture radar collect band-limited data from which an image of a target scene is rendered. The band-limited nature of the data generates sidelobes, or spilled energy, most evident in the neighborhood of bright point-like objects. It is generally considered desirable to minimize these sidelobes, even at the expense of some generally small increase in system bandwidth. This is accomplished by shaping the spectrum with window functions prior to inversion or transformation into an image. A window function that minimizes sidelobe energy can be constructed based on prolate spheroidal wave functions. A parametric design procedure allows doing so, even with constraints on allowable increases in system bandwidth. This approach is extended to accommodate spectral notches or holes, although the guaranteed minimum sidelobe energy can be quite high in this case. Interestingly, for a fixed bandwidth, the minimum mean-squared-error image rendering of a target scene is achieved with no windowing at all (rectangular or boxcar window). @Article{DickeyRomeroDoerry2003, author = {Fred M. Dickey and Louis A. Romero and Armin W. Doerry}, journal = {Optical Engineering}, title = {Window functions for imaging radar: a maximum energy approach to contiguous and notched spectrums}, year = {2003}, number = {7}, pages = {2113-2128}, volume = {42}, abstract = {Imaging systems such as synthetic aperture radar collect band-limited data from which an image of a target scene is rendered. The band-limited nature of the data generates sidelobes, or spilled energy, most evident in the neighborhood of bright point-like objects. It is generally considered desirable to minimize these sidelobes, even at the expense of some generally small increase in system bandwidth. This is accomplished by shaping the spectrum with window functions prior to inversion or transformation into an image. A window function that minimizes sidelobe energy can be constructed based on prolate spheroidal wave functions. A parametric design procedure allows doing so, even with constraints on allowable increases in system bandwidth. This approach is extended to accommodate spectral notches or holes, although the guaranteed minimum sidelobe energy can be quite high in this case. Interestingly, for a fixed bandwidth, the minimum mean-squared-error image rendering of a target scene is achieved with no windowing at all (rectangular or boxcar window).}, file = {:DickeyRomeroDoerry2003.pdf:PDF}, keywords = {SAR Processing, radar imaging, synthetic aperture radar, sidelobes, window functions, filtering, notched spectrum}, owner = {ofrey}, pdf = {../../../docs/DickeyRomeroDoerry2003.pdf}, publisher = {SPIE}, url = {http://link.aip.org/link/?JOE/42/2113/1}, } -
Michael Eineder.
Efficient simulation of SAR interferograms of large areas and of rugged terrain.
IEEE Transactions on Geoscience and Remote Sensing,
41(6):1415-1427,
June 2003.
Keyword(s): SAR Processing,
DEM generation,
InSAR,
SAR Interferometry,
Interferometry,
Tomography,
SAR Tomography,
digital elevation model generation,
interferometric synthetic aperture radar,
large areas,
remote sensing,
rugged terrain,
surface motion mapping,
radar imaging,
remote sensing by radar,
spaceborne radar,
synthetic aperture radar,
terrain mapping;.
Abstract: Interferometric synthetic aperture radar (InSAR) techniques are today applied in many areas of remote sensing, ranging from digital elevation model (DEM) generation to surface motion mapping and InSAR tomography. To enhance the understanding of the InSAR mapping process and to test new algorithms, accurate tools for the simulation of the topographic InSAR phase are necessary. Whereas the equations for the interferometric phase of a given DEM are well known, the actual implementation is tedious. Furthermore, a straightforward implementation would take far more computation time than all the other InSAR processing steps put together. This paper presents a novel algorithm for the efficient simulation of the InSAR phase, taking into account the special problems in mountainous terrain. Simulation results are compared to and illustrated with real data from the European Remote Sensing satellite (ERS-1/2) tandem mission and the Shuttle Radar Topography Mission (SRTM). Accuracy estimates for the phase simulation are given for different terrain types. The algorithm is described in enough detail that it can be implemented as a general-purpose tool for the accurate simulation of interferograms with virtually unlimited size, taking no more processing time than other InSAR processing steps. The algorithm in the presented form is used operationally within the interferometry software GENESIS to support the processing of SRTM/X-SAR data at the German Aerospace Center (DLR). @Article{1220250, author = {Eineder, Michael}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, title = {Efficient simulation of {SAR} interferograms of large areas and of rugged terrain}, year = {2003}, issn = {0196-2892}, month = jun, number = {6}, pages = {1415-1427}, volume = {41}, abstract = {Interferometric synthetic aperture radar (InSAR) techniques are today applied in many areas of remote sensing, ranging from digital elevation model (DEM) generation to surface motion mapping and InSAR tomography. To enhance the understanding of the InSAR mapping process and to test new algorithms, accurate tools for the simulation of the topographic InSAR phase are necessary. Whereas the equations for the interferometric phase of a given DEM are well known, the actual implementation is tedious. Furthermore, a straightforward implementation would take far more computation time than all the other InSAR processing steps put together. This paper presents a novel algorithm for the efficient simulation of the InSAR phase, taking into account the special problems in mountainous terrain. Simulation results are compared to and illustrated with real data from the European Remote Sensing satellite (ERS-1/2) tandem mission and the Shuttle Radar Topography Mission (SRTM). Accuracy estimates for the phase simulation are given for different terrain types. The algorithm is described in enough detail that it can be implemented as a general-purpose tool for the accurate simulation of interferograms with virtually unlimited size, taking no more processing time than other InSAR processing steps. The algorithm in the presented form is used operationally within the interferometry software GENESIS to support the processing of SRTM/X-SAR data at the German Aerospace Center (DLR).}, doi = {10.1109/TGRS.2003.811692}, keywords = {SAR Processing, DEM generation; InSAR, SAR Interferometry, Interferometry, Tomography; SAR Tomography; digital elevation model generation; interferometric synthetic aperture radar; large areas; remote sensing; rugged terrain; surface motion mapping; radar imaging; remote sensing by radar; spaceborne radar; synthetic aperture radar; terrain mapping;}, } -
Jeffrey A. Fessler and B. P. Sutton.
Nonuniform fast Fourier transforms using min-max interpolation.
IEEE Transactions on Signal Processing,
51(2):560-574,
February 2003.
Keyword(s): fast Fourier transforms,
frequency-domain analysis,
interpolation,
minimax techniques,
multidimensional signal processing,
signal sampling,
FFT,
Kaiser-Bessel function,
frequency domain,
min-max interpolation,
multidimensional signals,
nonuniform FT,
nonuniform fast Fourier transforms,
nonuniform sampling,
signal processing,
worst-case approximation error,
Approximation error,
Fast Fourier transforms,
Frequency domain analysis,
Image reconstruction,
Interpolation,
Iterative methods,
Magnetic resonance imaging,
Multidimensional signal processing,
Multidimensional systems,
Nonuniform sampling,
NFFT,
nonuniform FFT,
nonequispaced FFT.
Abstract: The fast Fourier transform (FFT) is used widely in signal processing for efficient computation of the FT of finite-length signals over a set of uniformly spaced frequency locations. However, in many applications, one requires nonuniform sampling in the frequency domain, i.e., a nonuniform FT. Several papers have described fast approximations for the nonuniform FT based on interpolating an oversampled FFT. This paper presents an interpolation method for the nonuniform FT that is optimal in the min-max sense of minimizing the worst-case approximation error over all signals of unit norm. The proposed method easily generalizes to multidimensional signals. Numerical results show that the min-max approach provides substantially lower approximation errors than conventional interpolation methods. The min-max criterion is also useful for optimizing the parameters of interpolation kernels such as the Kaiser-Bessel function. @Article{fesslerSuttonIEEETSiP2003NonUniformFFT, author = {Jeffrey A. Fessler and B. P. Sutton}, journal = {IEEE Transactions on Signal Processing}, title = {Nonuniform fast {F}ourier transforms using min-max interpolation}, year = {2003}, issn = {1053-587X}, month = feb, number = {2}, pages = {560-574}, volume = {51}, abstract = {The fast Fourier transform (FFT) is used widely in signal processing for efficient computation of the FT of finite-length signals over a set of uniformly spaced frequency locations. However, in many applications, one requires nonuniform sampling in the frequency domain, i.e., a nonuniform FT. Several papers have described fast approximations for the nonuniform FT based on interpolating an oversampled FFT. This paper presents an interpolation method for the nonuniform FT that is optimal in the min-max sense of minimizing the worst-case approximation error over all signals of unit norm. The proposed method easily generalizes to multidimensional signals. Numerical results show that the min-max approach provides substantially lower approximation errors than conventional interpolation methods. The min-max criterion is also useful for optimizing the parameters of interpolation kernels such as the Kaiser-Bessel function.}, doi = {10.1109/TSP.2002.807005}, file = {:fesslerSuttonIEEETSiP2003NonUniformFFT.pdf:PDF}, keywords = {fast Fourier transforms;frequency-domain analysis;interpolation;minimax techniques;multidimensional signal processing;signal sampling;FFT;Kaiser-Bessel function;frequency domain;min-max interpolation;multidimensional signals;nonuniform FT;nonuniform fast Fourier transforms;nonuniform sampling;signal processing;worst-case approximation error;Approximation error;Fast Fourier transforms;Frequency domain analysis;Image reconstruction;Interpolation;Iterative methods;Magnetic resonance imaging;Multidimensional signal processing;Multidimensional systems;Nonuniform sampling, NFFT, nonuniform FFT, nonequispaced FFT}, owner = {ofrey}, pdf = {../../../docs/fesslerSuttonIEEETSiP2003NonUniformFFT.pdf}, } -
J. R. Fienup and J. J. Miller.
Aberration correction by maximizing generalized sharpness metrics.
J. Opt. Soc. Am. A,
20(4):609-620,
April 2003.
Keyword(s): SAR Processing,
Autofocus,
Active or adaptive optics,
Image reconstruction techniques,
Image reconstruction-restoration,
Phase retrieval,
Image quality assessment,
Phased-array imaging systems,
Synthetic aperture radar,
Aberration correction,
Adaptive optics,
Discrete Fourier transforms,
Fast Fourier transforms,
Image quality,
Synthetic aperture radar.
Abstract: The technique of maximizing sharpness metrics has been used to estimate and compensate for aberrations with adaptive optics, to correct phase errors in synthetic-aperture radar, and to restore images. The largest class of sharpness metrics is the sum over a nonlinear point transformation of the image intensity. How the second derivative of the point nonlinearity varies with image intensity determines the effects of various metrics on the imagery. Some metrics emphasize making shadows darker, and other emphasize making bright points brighter. One can determine the image content needed to pick the best metric by computing the statistics of the image autocorrelation or of the Fourier magnitude, either of which is independent of the phase error. Computationally efficient, closed-form expressions for the gradient make possible efficient search algorithms to maximize sharpness. @Article{fienupMillerJOptSoc2003AutofocusAberationCorrectionMaximizingSharpnessMetrics, author = {J. R. Fienup and J. J. Miller}, journal = {J. Opt. Soc. Am. A}, title = {Aberration correction by maximizing generalized sharpness metrics}, year = {2003}, month = {Apr}, number = {4}, pages = {609--620}, volume = {20}, abstract = {The technique of maximizing sharpness metrics has been used to estimate and compensate for aberrations with adaptive optics, to correct phase errors in synthetic-aperture radar, and to restore images. The largest class of sharpness metrics is the sum over a nonlinear point transformation of the image intensity. How the second derivative of the point nonlinearity varies with image intensity determines the effects of various metrics on the imagery. Some metrics emphasize making shadows darker, and other emphasize making bright points brighter. One can determine the image content needed to pick the best metric by computing the statistics of the image autocorrelation or of the Fourier magnitude, either of which is independent of the phase error. Computationally efficient, closed-form expressions for the gradient make possible efficient search algorithms to maximize sharpness.}, doi = {10.1364/JOSAA.20.000609}, keywords = {SAR Processing, Autofocus, Active or adaptive optics; Image reconstruction techniques; Image reconstruction-restoration; Phase retrieval; Image quality assessment; Phased-array imaging systems; Synthetic aperture radar; Aberration correction; Adaptive optics; Discrete Fourier transforms; Fast Fourier transforms; Image quality; Synthetic aperture radar}, owner = {ofrey}, publisher = {OSA}, url = {http://josaa.osa.org/abstract.cfm?URI=josaa-20-4-609}, } -
G. Fornaro,
F. Serafino,
and F. Soldovieri.
Three-dimensional focusing with multipass SAR data.
IEEE Trans. Geosci. Remote Sens.,
41(3):507-517,
2003.
Keyword(s): SAR Processing,
SAR Tomography,
Tomography,
focusing,
synthetic aperture radar,
3D tomography reconstruction,
linear inverse problem,
multipass SAR data,
multipass synthetic aperture radar data,
nonuniform orbit separation,
processing technique,
scattering mechanism,
singular value decomposition,
volumetric scattering.
Abstract: Deals with the use of multipass synthetic aperture radar (SAR) data in order to achieve three-dimensional tomography reconstruction in presence of volumetric scattering. Starting from azimuth- and range-focused SAR data relative to the same area, neglecting any mutual interaction between the targets, and assuming the propagation in homogeneous media, we investigate the possibility to focus the data also in the elevation direction. The problem is formulated in the framework of linear inverse problem and the solution makes use of the singular value decomposition of the relevant operator. This allows us to properly take into account nonuniform orbit separation and to exploit a priori knowledge regarding the size of the volume interested by the scattering mechanism, thus leading to superresolution in the elevation direction. Results obtained on simulated data demonstrate the feasibility of the proposed processing technique. @Article{fornaroSerafinoSoldovieri03:Tomo, author = {Fornaro, G. and Serafino, F. and Soldovieri, F.}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {Three-dimensional focusing with multipass {SAR} data}, year = {2003}, issn = {0196-2892}, number = {3}, pages = {507--517}, volume = {41}, abstract = {Deals with the use of multipass synthetic aperture radar (SAR) data in order to achieve three-dimensional tomography reconstruction in presence of volumetric scattering. Starting from azimuth- and range-focused SAR data relative to the same area, neglecting any mutual interaction between the targets, and assuming the propagation in homogeneous media, we investigate the possibility to focus the data also in the elevation direction. The problem is formulated in the framework of linear inverse problem and the solution makes use of the singular value decomposition of the relevant operator. This allows us to properly take into account nonuniform orbit separation and to exploit a priori knowledge regarding the size of the volume interested by the scattering mechanism, thus leading to superresolution in the elevation direction. Results obtained on simulated data demonstrate the feasibility of the proposed processing technique.}, keywords = {SAR Processing, SAR Tomography, Tomography, focusing, synthetic aperture radar, 3D tomography reconstruction, linear inverse problem, multipass SAR data, multipass synthetic aperture radar data, nonuniform orbit separation, processing technique, scattering mechanism, singular value decomposition, volumetric scattering}, owner = {ofrey}, pdf = {../../../docs/fornaroSerafinoSoldovieriTomo03.pdf}, url = {http://ieeexplore.ieee.org/iel5/36/26979/01198642.pdf}, } -
Jong-Sen Lee,
Shane R. Cloude,
Konstantinos P. Papathanassiou,
M. R. Grunes,
and I. H. Woodhouse.
Speckle filtering and coherence estimation of polarimetric SAR interferometry data for forest applications.
IEEE Trans. Geosci. Remote Sens.,
41(10):2254-2263,
October 2003.
Keyword(s): SAR Processing,
Forest,
Forest parameters,
biomass,
averaging,
boxcar filter,
coherence estimation,
forest applications,
forest heights,
ground topography,
interferometric coherence,
neighboring pixels,
polarimetric SAR interferometry data,
polarimetric interferometry matrix,
polarimetric synthetic aperture radar interferometry,
random volume,
scattering characteristics,
speckle filtering,
adaptive filters,
forestry,
radar imaging,
radar polarimetry,
radiowave interferometry,
remote sensing by radar,
speckle,
synthetic aperture radar.
Abstract: Recently, polarimetric synthetic aperture radar (SAR) interferometry has generated much interest for forest applications. Forest heights and ground topography can be extracted based on interferometric coherence using a random volume over ground coherent mixture model. The coherence estimation is of paramount importance for the accuracy of forest height estimation. The coherence (or correlation coefficient) is a statistical average of neighboring pixels of similar scattering characteristics. The commonly used algorithm is the boxcar filter, which has the deficiency of indiscriminate averaging of neighboring pixels. The result is that coherence values are lower than they should be. In this paper, we propose a new algorithm to improve the accuracy in the coherence estimation based on speckle filtering of the 6 times;6 polarimetric interferometry matrix. Simulated images are used to verify the effectiveness of this adaptive algorithm. German Aerospace Center (DLR) L-Band E-SAR data are applied to demonstrate the improved accuracy in coherence and in forest height estimation. @Article{leeCloudePapthanassiouGrunesWoodhouse2003:PolInSARForestApplications, author = {Jong-Sen Lee and Cloude, Shane R. and Papathanassiou, Konstantinos P. and Grunes, M. R. and Woodhouse, I. H.}, title = {Speckle filtering and coherence estimation of polarimetric {SAR} interferometry data for forest applications}, journal = {IEEE Trans. Geosci. Remote Sens.}, year = {2003}, volume = {41}, number = {10}, pages = {2254-2263}, month = oct, issn = {0196-2892}, abstract = {Recently, polarimetric synthetic aperture radar (SAR) interferometry has generated much interest for forest applications. Forest heights and ground topography can be extracted based on interferometric coherence using a random volume over ground coherent mixture model. The coherence estimation is of paramount importance for the accuracy of forest height estimation. The coherence (or correlation coefficient) is a statistical average of neighboring pixels of similar scattering characteristics. The commonly used algorithm is the boxcar filter, which has the deficiency of indiscriminate averaging of neighboring pixels. The result is that coherence values are lower than they should be. In this paper, we propose a new algorithm to improve the accuracy in the coherence estimation based on speckle filtering of the 6 times;6 polarimetric interferometry matrix. Simulated images are used to verify the effectiveness of this adaptive algorithm. German Aerospace Center (DLR) L-Band E-SAR data are applied to demonstrate the improved accuracy in coherence and in forest height estimation.}, doi = {10.1109/TGRS.2003.817196}, keywords = {SAR Processing, Forest, Forest parameters, biomass, averaging; boxcar filter; coherence estimation; forest applications; forest heights; ground topography; interferometric coherence; neighboring pixels; polarimetric SAR interferometry data; polarimetric interferometry matrix; polarimetric synthetic aperture radar interferometry; random volume; scattering characteristics; speckle filtering; adaptive filters; forestry; radar imaging; radar polarimetry; radiowave interferometry; remote sensing by radar; speckle; synthetic aperture radar}, } -
D. Leva,
G. Nico,
D. Tarchi,
J. Fortuny-Guasch,
and A.J. Sieber.
Temporal analysis of a landslide by means of a ground-based SAR Interferometer.
IEEE Trans. Geosci. Remote Sens.,
41(4):745-752,
April 2003.
Keyword(s): Feeds,
Global Positioning System,
Image sequence analysis,
Instruments,
Interferometry,
Layout,
Monitoring,
Morphology,
Position measurement,
Terrain factors,
geomorphology,
geophysical techniques,
radiowave interferometry,
synthetic aperture radar,
terrain mapping,
16.70 to 16.78 GHz,
700 to 1150 m,
Austria,
D-InSAR,
GBSAR interferometer,
GPS receivers,
Schwaz,
Tyrol,
accumulation zone,
debris flow,
deformation map,
differential synthetic aperture radar interferometry,
ground-based synthetic aperture radar interferometer,
high-resolution images,
interferogram sequence,
landslide monitoring,
landslides,
phase image analysis,
slowly deforming upper scarp,
terrain morphology,
velocity field;.
Abstract: A ground-based synthetic aperture radar (GB-SAR) interferometer is used to retrieve the velocity field of a landslide. High-resolution images are obtained by means of a time domain SAR processor. An in-depth analysis of the sequence of SAR interferograms enables the recognition of a slowly deforming upper scarp in the scene, and a debris flow that feeds the accumulation zone of the landslide, where a fast change in terrain morphology is observed. The estimated deformation map is in agreement with the available measurements obtained by means of Global Positioning System receivers. Results show that GB-SAR interferometry is a cost-effective solution for the monitoring of landslides. The proposed method is shown to be a valid complement to space- and airborne SAR and to the traditional geodetic instruments. @Article{levaNicoTarchiFortunyGuaschSieberTGRS2003GroundBasedSAR, author = {Leva, D. and Nico, G. and Tarchi, D. and Fortuny-Guasch, J. and Sieber, A.J.}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {Temporal analysis of a landslide by means of a ground-based {SAR} Interferometer}, year = {2003}, issn = {0196-2892}, month = apr, number = {4}, pages = {745-752}, volume = {41}, abstract = {A ground-based synthetic aperture radar (GB-SAR) interferometer is used to retrieve the velocity field of a landslide. High-resolution images are obtained by means of a time domain SAR processor. An in-depth analysis of the sequence of SAR interferograms enables the recognition of a slowly deforming upper scarp in the scene, and a debris flow that feeds the accumulation zone of the landslide, where a fast change in terrain morphology is observed. The estimated deformation map is in agreement with the available measurements obtained by means of Global Positioning System receivers. Results show that GB-SAR interferometry is a cost-effective solution for the monitoring of landslides. The proposed method is shown to be a valid complement to space- and airborne SAR and to the traditional geodetic instruments.}, doi = {10.1109/TGRS.2003.808902}, file = {:levaNicoTarchiFortunyGuaschSieberTGRS2003GroundBasedSAR.pdf:PDF}, keywords = {Feeds;Global Positioning System;Image sequence analysis;Instruments;Interferometry;Layout;Monitoring;Morphology;Position measurement;Terrain factors; geomorphology; geophysical techniques; radiowave interferometry; synthetic aperture radar; terrain mapping; 16.70 to 16.78 GHz; 700 to 1150 m; Austria; D-InSAR; GBSAR interferometer; GPS receivers; Schwaz; Tyrol; accumulation zone; debris flow; deformation map; differential synthetic aperture radar interferometry; ground-based synthetic aperture radar interferometer; high-resolution images; interferogram sequence; landslide monitoring; landslides; phase image analysis; slowly deforming upper scarp; terrain morphology; velocity field;}, pdf = {../../../docs/levaNicoTarchiFortunyGuaschSieberTGRS2003GroundBasedSAR.pdf}, } -
Jian Li,
Petre Stoica,
and Zhisong Wang.
On robust Capon beamforming and diagonal loading.
Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on],
51(7):1702-1715,
2003.
Keyword(s): SAR Processing,
Capon,
Spectral Estimation,
Beamforming,
array signal processing,
interference suppression,
parameter estimation,
signal resolution,
SOI power estimation,
SOI steering vector,
adaptive arrays,
array steering vector,
data-independent beamformer,
diagonal loading,
interference rejection,
robust Capon beamforming,
signal of interest,
standard Capon beamformer,
uncertain steering vectors,
uncertainty set.
Abstract: The Capon (1969) beamformer has better resolution and much better interference rejection capability than the standard (data-independent) beamformer, provided that the array steering vector corresponding to the signal of interest (SOI) is accurately known. However, whenever the knowledge of the SOI steering vector is imprecise (as is often the case in practice), the performance of the Capon beamformer may become worse than that of the standard beamformer. Diagonal loading (including its extended versions) has been a popular approach to improve the robustness of the Capon beamformer. We show that a natural extension of the Capon beamformer to the case of uncertain steering vectors also belongs to the class of diagonal loading approaches, but the amount of diagonal loading can be precisely calculated based on the uncertainty set of the steering vector. The proposed robust Capon beamformer can be efficiently computed at a comparable cost with that of the standard Capon beamformer. Its excellent performance for SOI power estimation is demonstrated via a number of numerical examples. @Article{LiStoicaWang2003:RobustCapon, author = {Li, Jian and Stoica, Petre and Wang, Zhisong}, journal = {Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on]}, title = {{On robust Capon beamforming and diagonal loading}}, year = {2003}, issn = {1053-587X}, number = {7}, pages = {1702--1715}, volume = {51}, abstract = {The Capon (1969) beamformer has better resolution and much better interference rejection capability than the standard (data-independent) beamformer, provided that the array steering vector corresponding to the signal of interest (SOI) is accurately known. However, whenever the knowledge of the SOI steering vector is imprecise (as is often the case in practice), the performance of the Capon beamformer may become worse than that of the standard beamformer. Diagonal loading (including its extended versions) has been a popular approach to improve the robustness of the Capon beamformer. We show that a natural extension of the Capon beamformer to the case of uncertain steering vectors also belongs to the class of diagonal loading approaches, but the amount of diagonal loading can be precisely calculated based on the uncertainty set of the steering vector. The proposed robust Capon beamformer can be efficiently computed at a comparable cost with that of the standard Capon beamformer. Its excellent performance for SOI power estimation is demonstrated via a number of numerical examples.}, booktitle = {Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on]}, keywords = {SAR Processing, Capon, Spectral Estimation, Beamforming, array signal processing, interference suppression, parameter estimation, signal resolution, SOI power estimation, SOI steering vector, adaptive arrays, array steering vector, data-independent beamformer, diagonal loading, interference rejection, robust Capon beamforming, signal of interest, standard Capon beamformer, uncertain steering vectors, uncertainty set}, owner = {ofrey}, pdf = {../../../docs/LiStoicaWang2003.pdf}, url = {http://ieeexplore.ieee.org/iel5/78/27152/01206680.pdf}, } -
D. Lloyd and I. D. Longstaff.
Ultra-wideband multistatic SAR for the detection and location of landmines.
IEE Proceedings - Radar, Sonar and Navigation,
150:158-164(6),
June 2003.
Keyword(s): location,
small mine-like objects,
ground coordinates,
target strengths,
signal to clutter ratio,
bistatic antenna configurations,
ultra-wideband multistatic SAR,
reference depression angle,
detection,
target-to-clutter ratios,
thresholding,
images,
amplitude distribution,
landmines;.
Abstract: Techniques for improving the signal to clutter ratio of an ultra-wideband SAR designed to detect small mine-like objects in the surface of the ground were investigated. In particular, images were collected using different bistatic antenna configurations in an attempt to decorrelate the clutter with respect to the targets. The images were converted to a reference depression angle, summed, and then converted to ground coordinates. The resulting target strengths were then compared with the amplitude distribution of the ground clutter to show the improvement obtained. While some improvement was demonstrated, this was for the relatively easy scenario of targets on the surface partially obscured by grass. Detection based on thresholding the raw RF signal (the bipolar response) rather than the envelope (baseband I2+Q2) was also considered to further enhance target-to-clutter ratios. @Article{lloydLongstaffIEEProcRadSonNav2003UltraWidebandMultistaticSARForLandMineDetection, author = {Lloyd, D. and Longstaff, I. D.}, journal = {IEE Proceedings - Radar, Sonar and Navigation}, title = {Ultra-wideband multistatic {SAR} for the detection and location of landmines}, year = {2003}, issn = {1350-2395}, month = {June}, pages = {158-164(6)}, volume = {150}, abstract = {Techniques for improving the signal to clutter ratio of an ultra-wideband SAR designed to detect small mine-like objects in the surface of the ground were investigated. In particular, images were collected using different bistatic antenna configurations in an attempt to decorrelate the clutter with respect to the targets. The images were converted to a reference depression angle, summed, and then converted to ground coordinates. The resulting target strengths were then compared with the amplitude distribution of the ground clutter to show the improvement obtained. While some improvement was demonstrated, this was for the relatively easy scenario of targets on the surface partially obscured by grass. Detection based on thresholding the raw RF signal (the bipolar response) rather than the envelope (baseband I2+Q2) was also considered to further enhance target-to-clutter ratios.}, doi = {10.1049/ip-rsn:20030444}, file = {:lloydLongstaffIEEProcRadSonNav2003UltraWidebandMultistaticSARForLandMineDetection.pdf:PDF}, issue = {3}, keywords = {location;small mine-like objects;ground coordinates;target strengths;signal to clutter ratio;bistatic antenna configurations;ultra-wideband multistatic SAR;reference depression angle;detection;target-to-clutter ratios;thresholding;images;amplitude distribution;landmines;}, language = {English}, owner = {ofrey}, url = {https://digital-library.theiet.org/content/journals/10.1049/ip-rsn_20030444}, } -
F. Lombardini,
M. Montanari,
and F. Gini.
Reflectivity estimation for multibaseline interferometric radar imaging of layover extended sources.
IEEE Transactions on Signal Processing,
51(6):1508-1519,
June 2003.
Keyword(s): SAR Processing,
Tomography,
SAR Tomography,
Multi-baseline SAR,
Interferometry,
SAR Interferometry,
AWGN,
Monte Carlo methods,
amplitude estimation,
radar imaging,
radiowave interferometry,
synthetic aperture radar APES,
Capon's approach,
InSAR,
Monte Carlo simulation,
RELAX,
SAR,
additive white Gaussian noise,
complex orography,
component sinusoidal signal,
hybrid spectral estimators,
layover extended sources,
multibaseline interferometric radar imaging,
multibaseline operation,
multiplicative complex correlated noise,
nonparametric estimators,
parametric estimators,
reflectivity estimation,
spatial frequency estimation,
synthetic aperture radar interferometry,
terrain height,
undistorted multibaseline image formation.
Abstract: In recent years, there has been great interest in exploiting the advanced multibaseline operation of synthetic aperture radar interferometry (InSAR) for solving layover effects from complex orography, which can degrade both SAR and InSAR imagery of terrain radar reflectivity and height. In this work, the problem of retrieving radar reflectivity of layover areas is addressed. It is formulated as the problem of estimating a multicomponent sinusoidal signal corrupted by multiplicative complex correlated noise and additive white Gaussian noise. Application of nonparametric [e.g., Capon, amplitude and phase estimation filter (APES)], parametric [least squares, modern parametric RELAXation spectral estimator (RELAX)], and hybrid spectral estimators for amplitude estimation is investigated for a multilook scenario. In particular, the multilook extensions of RELAX and APES are applied to the interferometric problem. Performance analysis is investigated through a Cramer-Rao lower bound calculation and Monte Carlo simulation. The method of least squares, coupled with Capon's approach to spatial frequency estimation, multilook APES, and multilook RELAX turn out to provide accurate reflectivity estimates for undistorted multibaseline image formation of layover areas. @Article{lombardiniMontanariGini2003:Tomo, author = {Lombardini, F. and Montanari, M. and Gini, F.}, journal = {IEEE Transactions on Signal Processing}, title = {Reflectivity estimation for multibaseline interferometric radar imaging of layover extended sources}, year = {2003}, issn = {1053-587X}, month = {jun}, number = {6}, pages = {1508-1519}, volume = {51}, abstract = {In recent years, there has been great interest in exploiting the advanced multibaseline operation of synthetic aperture radar interferometry (InSAR) for solving layover effects from complex orography, which can degrade both SAR and InSAR imagery of terrain radar reflectivity and height. In this work, the problem of retrieving radar reflectivity of layover areas is addressed. It is formulated as the problem of estimating a multicomponent sinusoidal signal corrupted by multiplicative complex correlated noise and additive white Gaussian noise. Application of nonparametric [e.g., Capon, amplitude and phase estimation filter (APES)], parametric [least squares, modern parametric RELAXation spectral estimator (RELAX)], and hybrid spectral estimators for amplitude estimation is investigated for a multilook scenario. In particular, the multilook extensions of RELAX and APES are applied to the interferometric problem. Performance analysis is investigated through a Cramer-Rao lower bound calculation and Monte Carlo simulation. The method of least squares, coupled with Capon's approach to spatial frequency estimation, multilook APES, and multilook RELAX turn out to provide accurate reflectivity estimates for undistorted multibaseline image formation of layover areas.}, keywords = {SAR Processing, Tomography, SAR Tomography, Multi-baseline SAR, Interferometry, SAR Interferometry, AWGN, Monte Carlo methods, amplitude estimation, radar imaging, radiowave interferometry, synthetic aperture radar APES, Capon's approach, InSAR, Monte Carlo simulation, RELAX, SAR, additive white Gaussian noise, complex orography, component sinusoidal signal, hybrid spectral estimators, layover extended sources, multibaseline interferometric radar imaging, multibaseline operation, multiplicative complex correlated noise, nonparametric estimators, parametric estimators, reflectivity estimation, spatial frequency estimation, synthetic aperture radar interferometry, terrain height, undistorted multibaseline image formation}, owner = {ofrey}, pdf = {../../../docs/lombardiniMontanariGini2003.pdf}, url = {http://ieeexplore.ieee.org/iel5/78/27018/01200140.pdf}, } -
A. Luckman and W. Grey.
Urban building height variance from multibaseline ERS coherence.
IEEE Transactions on Geoscience and Remote Sensing,
41(9):2022-2025,
September 2003.
Keyword(s): Cardiff,
ERS images,
European Remote Sensing satellite,
InSAR,
UK,
Wales,
central business district,
coherence maps,
interferometric synthetic aperture radar coherence images,
multibaseline ERS coherence,
surface roughness,
urban building height variance,
urban decorrelation models,
vertical scatterer distributions,
radar imaging,
remote sensing by radar,
synthetic aperture radar,
terrain mapping;.
Abstract: Multibaseline European Remote Sensing (ERS) interferometric synthetic aperture radar coherence images from Cardiff, U.K. are investigated with respect to urban form. A model of spatial coherence, taking into account the vertical distribution of scatterers, is inverted to allow urban building height variance to be retrieved. Sixty-nine coherence maps are employed, generated from 20 ERS images. No a priori information is required in the analysis. However, realistic vertical scatterer distributions are retrieved, and Cardiff's central business district is automatically identified. This analysis demonstrates the utility of the urban decorrelation models employed. @Article{luckmanGrey2003, author = {Luckman, A. and Grey, W.}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, title = {Urban building height variance from multibaseline ERS coherence}, year = {2003}, issn = {0196-2892}, month = sep, number = {9}, pages = {2022-2025}, volume = {41}, abstract = {Multibaseline European Remote Sensing (ERS) interferometric synthetic aperture radar coherence images from Cardiff, U.K. are investigated with respect to urban form. A model of spatial coherence, taking into account the vertical distribution of scatterers, is inverted to allow urban building height variance to be retrieved. Sixty-nine coherence maps are employed, generated from 20 ERS images. No a priori information is required in the analysis. However, realistic vertical scatterer distributions are retrieved, and Cardiff's central business district is automatically identified. This analysis demonstrates the utility of the urban decorrelation models employed.}, doi = {10.1109/TGRS.2003.815236}, keywords = {Cardiff; ERS images; European Remote Sensing satellite; InSAR; UK; Wales; central business district; coherence maps; interferometric synthetic aperture radar coherence images; multibaseline ERS coherence; surface roughness; urban building height variance; urban decorrelation models; vertical scatterer distributions; radar imaging; remote sensing by radar; synthetic aperture radar; terrain mapping;}, } -
Oscar Mora,
Jordi J. Mallorquì,
and Antoni Broquetas.
Linear and nonlinear terrain deformation maps from a reduced set of interferometric SAR images.
IEEE Trans. Geosci. Remote Sens.,
41(10):2243-2253,
October 2003.
Keyword(s): SAR Processing,
geophysical signal processing,
radar imaging,
radiowave interferometry,
remote sensing by radar,
synthetic aperture radar,
terrain mapping,
topography (Earth),
DEM,
Delauney triangulation,
atmospheric artifacts,
coherence level,
digital elevation model,
filtering techniques,
interferometric SAR images,
linear terrain deformation maps,
low spatial resolution interferograms,
nonlinear terrain deformation maps,
nonuniform mesh,
remote sensing,
synthetic aperture radar,
topographic terms,
Atmospheric modeling,
Coherence,
Digital elevation models,
Information filtering,
Information filters,
Information retrieval,
Remote sensing,
Spatial resolution,
Synthetic aperture radar,
Testing,
PSI,
Persistent Scatterer Interferometry.
Abstract: In this paper, an advanced technique for the generation of deformation maps using synthetic aperture radar (SAR) data is presented. The algorithm estimates the linear and nonlinear components of the displacement, the error of the digital elevation model (DEM) used to cancel the topographic terms, and the atmospheric artifacts from a reduced set of low spatial resolution interferograms. The pixel candidates are selected from those presenting a good coherence level in the whole set of interferograms and the resulting nonuniform mesh tessellated with the Delauney triangulation to establish connections among them. The linear component of movement and DEM error are estimated adjusting a linear model to the data only on the connections. Later on, this information, once unwrapped to retrieve the absolute values, is used to calculate the nonlinear component of movement and atmospheric artifacts with alternate filtering techniques in both the temporal and spatial domains. The method presents high flexibility with respect to the required number of images and the baselines length. However, better results are obtained with large datasets of short baseline interferograms. The technique has been tested with European Remote Sensing SAR data from an area of Catalonia (Spain) and validated with on-field precise leveling measurements. @Article{moraMallorquiBroquetasTGARS2003, author = {Mora, Oscar and Mallorqu{\'i}, Jordi J. and Broquetas, Antoni}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {Linear and nonlinear terrain deformation maps from a reduced set of interferometric {SAR} images}, year = {2003}, issn = {0196-2892}, month = oct, number = {10}, pages = {2243-2253}, volume = {41}, abstract = {In this paper, an advanced technique for the generation of deformation maps using synthetic aperture radar (SAR) data is presented. The algorithm estimates the linear and nonlinear components of the displacement, the error of the digital elevation model (DEM) used to cancel the topographic terms, and the atmospheric artifacts from a reduced set of low spatial resolution interferograms. The pixel candidates are selected from those presenting a good coherence level in the whole set of interferograms and the resulting nonuniform mesh tessellated with the Delauney triangulation to establish connections among them. The linear component of movement and DEM error are estimated adjusting a linear model to the data only on the connections. Later on, this information, once unwrapped to retrieve the absolute values, is used to calculate the nonlinear component of movement and atmospheric artifacts with alternate filtering techniques in both the temporal and spatial domains. The method presents high flexibility with respect to the required number of images and the baselines length. However, better results are obtained with large datasets of short baseline interferograms. The technique has been tested with European Remote Sensing SAR data from an area of Catalonia (Spain) and validated with on-field precise leveling measurements.}, doi = {10.1109/TGRS.2003.814657}, file = {:moraMallorquiBroquetasTGARS2003.pdf:PDF}, keywords = {SAR Processing, geophysical signal processing;radar imaging;radiowave interferometry;remote sensing by radar;synthetic aperture radar;terrain mapping;topography (Earth);DEM;Delauney triangulation;atmospheric artifacts;coherence level;digital elevation model;filtering techniques;interferometric SAR images;linear terrain deformation maps;low spatial resolution interferograms;nonlinear terrain deformation maps;nonuniform mesh;remote sensing;synthetic aperture radar;topographic terms;Atmospheric modeling;Coherence;Digital elevation models;Information filtering;Information filters;Information retrieval;Remote sensing;Spatial resolution;Synthetic aperture radar;Testing, PSI, Persistent Scatterer Interferometry}, owner = {ofrey}, } -
Clifford J. Nolan and Margaret Cheney.
Synthetic Aperture Inversion for Arbitrary Flight Paths and Nonflat Topography.
IEEE Transactions on Image Processing,
12(9):1035-1043,
September 2003.
Keyword(s): SAR Processing,
Back-Projection,
Time-Domain Back-Projection,
TDBP,
FOPEN,
Non-Flat Topography,
Non-Linear Flight Path.
Abstract: This paper considers synthetic aperture radar (SAR) and other synthetic aperture imaging systems in which a backscattered wave is measured from positions along an arbitrary (known) flight path.We assume a single-scattering model for the radar data, and we assume that the ground topography is known but not necessarily flat. We focus on cases in which the antenna footprint is so large that the standard narrow-beam algorithms are not useful.We showthat certain artifacts can be avoided if the antenna and antenna footprint avoid particular relationships with the ground topography. In this case, we give an explicit backprojection imaging algorithm that corrects for the ground topography, flight path, antenna beam pattern, source waveform, and other geometrical factors. For the case of a nondirectional antenna, the image produced by the above algorithm contains artifacts. For this case, we analyze the strength of the artifacts relative to the strength of the true image. The analysis shows that the artifacts can be somewhat suppressed by increasing the frequency, integration time, and the curvature of the flight path. @Article{nolan:SARInversion2, Title = {{Synthetic Aperture Inversion for Arbitrary Flight Paths and Nonflat Topography}}, Author = {Clifford J. Nolan and Margaret Cheney}, Month = sep, Number = {9}, Pages = {1035-1043}, Url = {www.rpi.edu/~cheney/papers/sarieeereprint.pdf}, Volume = {12}, Year = {2003}, Abstract = {This paper considers synthetic aperture radar (SAR) and other synthetic aperture imaging systems in which a backscattered wave is measured from positions along an arbitrary (known) flight path.We assume a single-scattering model for the radar data, and we assume that the ground topography is known but not necessarily flat. We focus on cases in which the antenna footprint is so large that the standard narrow-beam algorithms are not useful.We showthat certain artifacts can be avoided if the antenna and antenna footprint avoid particular relationships with the ground topography. In this case, we give an explicit backprojection imaging algorithm that corrects for the ground topography, flight path, antenna beam pattern, source waveform, and other geometrical factors. For the case of a nondirectional antenna, the image produced by the above algorithm contains artifacts. For this case, we analyze the strength of the artifacts relative to the strength of the true image. The analysis shows that the artifacts can be somewhat suppressed by increasing the frequency, integration time, and the curvature of the flight path.}, Journal = {IEEE Transactions on Image Processing}, Keywords = {SAR Processing, Back-Projection, Time-Domain Back-Projection, TDBP, FOPEN, Non-Flat Topography, Non-Linear Flight Path}, Pdf = {../../../docs/nolan03.pdf} } -
M. Nolan and D. R. Fatland.
Penetration depth as a DInSAR observable and proxy for soil moisture.
IEEE_J_GRS,
41(3):532-537,
March 2003.
Keyword(s): ground penetrating radar,
moisture measurement,
radiowave interferometry,
remote sensing by radar,
soil,
synthetic aperture radar,
C-band,
L-band,
X-band,
agriculture,
attenuation,
clay rich soils,
clay swelling,
deformation signals,
differential interferometric synthetic aperture radar,
digital elevation models,
microwave penetration depth,
remote sensing,
soil moisture,
surface deformation,
synthetic aperture radar microwaves,
terrain mapping,
volumetric water content,
Interferometry,
Microwave theory and techniques,
Moisture measurement,
Radar detection,
Remote sensing,
Soil measurements,
Soil moisture,
Surface topography,
Synthetic aperture radar.
@Article{Nolan2003, author = {M. Nolan and D. R. Fatland}, journal = IEEE_J_GRS, title = {Penetration depth as a DInSAR observable and proxy for soil moisture}, year = {2003}, issn = {0196-2892}, month = mar, number = {3}, pages = {532--537}, volume = {41}, doi = {10.1109/TGRS.2003.809931}, keywords = {ground penetrating radar, moisture measurement, radiowave interferometry, remote sensing by radar, soil, synthetic aperture radar, C-band, L-band, X-band, agriculture, attenuation, clay rich soils, clay swelling, deformation signals, differential interferometric synthetic aperture radar, digital elevation models, microwave penetration depth, remote sensing, soil moisture, surface deformation, synthetic aperture radar microwaves, terrain mapping, volumetric water content, Interferometry, Microwave theory and techniques, Moisture measurement, Radar detection, Remote sensing, Soil measurements, Soil moisture, Surface topography, Synthetic aperture radar}, owner = {ofrey}, } -
Christine Pielmeier and Martin Schneebeli.
Developments in the Stratigraphy of Snow.
Surveys in Geophysics,
24(5-6):389-416,
2003.
Keyword(s): Snow,
Snow Stratigraphy,
mechanical properties,
physical properties,
profile,
snow cover,
snow properties.
Abstract: Snow on the ground can be regarded as aeolian sediment with rapidly changing properties. We explore the Swiss (Alpine) history of stratigraphy of snow to show the trends and developments. The observation of snow stratigraphy starts in the 18th and 19th century with a geologic focus, descriptions are superficial and only verbal. In the early 20th century, the scientific interest in snow stratigraphy increases. Detailed descriptions and drawings become available. Slope scale geomorphologic features and surface processes were observed and documented. Starting from the 1940s, a shift of interest to the physical and mechanical properties in ''homogeneous'' layers takes place, from a slope-centred approach to a sample-centred approach. Stratigraphic description becomes one-dimensional, and the concept of well-defined layers gets accepted and still predominates today. However, all physical and mechanical processes are strongly related to the spatial variability of the snow mechanical properties. New instrumental developments show that the perceived strict layering may be a too simple model. The requirements for modern snow stratigraphy, integrating different scales and modern technology, is discussed from an international viewpoint. @Article{pielmeierSchneebeli2013DevelopmentsStratigraphyOfSnow, author = {Christine Pielmeier and Martin Schneebeli}, title = {Developments in the Stratigraphy of Snow}, journal = {Surveys in Geophysics}, year = {2003}, volume = {24}, number = {5-6}, pages = {389-416}, issn = {1573-0956}, abstract = {Snow on the ground can be regarded as aeolian sediment with rapidly changing properties. We explore the Swiss (Alpine) history of stratigraphy of snow to show the trends and developments. The observation of snow stratigraphy starts in the 18th and 19th century with a geologic focus, descriptions are superficial and only verbal. In the early 20th century, the scientific interest in snow stratigraphy increases. Detailed descriptions and drawings become available. Slope scale geomorphologic features and surface processes were observed and documented. Starting from the 1940s, a shift of interest to the physical and mechanical properties in ''homogeneous'' layers takes place, from a slope-centred approach to a sample-centred approach. Stratigraphic description becomes one-dimensional, and the concept of well-defined layers gets accepted and still predominates today. However, all physical and mechanical processes are strongly related to the spatial variability of the snow mechanical properties. New instrumental developments show that the perceived strict layering may be a too simple model. The requirements for modern snow stratigraphy, integrating different scales and modern technology, is discussed from an international viewpoint.}, doi = {10.1023/B:GEOP.0000006073.25155.b0}, file = {:pielmeierSchneebeli2013DevelopmentsStratigraphyOfSnow.pdf:PDF}, keywords = {Snow, Snow Stratigraphy, mechanical properties, physical properties, profile, snow cover, snow properties}, owner = {ofrey}, } -
Pau Prats and Jordi J. Mallorqui.
Estimation of azimuth phase undulations with multisquint processing in airborne interferometric SAR images.
IEEE Trans. Geosci. Remote Sens.,
41(6):1530-1533,
2003.
Keyword(s): SAR Processing,
Squinted SAR,
airborne radar,
radar imaging,
synthetic aperture radar,
ESAR,
DLR experimental airborne SAR,
Germany,
Oberpfaffenhofen test site,
azimuth phase undulations,
calibration,
image pairs,
interferometric airborne synthetic aperture radar systems,
multisquint processing,
phase error correction,
phase error detection,
single-pass interferometrie data,
squint angles,
technique,
InSAR,
Interferometry.
Abstract: Presents a technique to detect and correct phase errors appearing in interferometric airborne synthetic aperture radar (SAR) systems due to the lack of precision in the navigation system. The technique is based on a multisquint processing approach, i.e. by processing the same image pairs with different squint angles we can combine the information of different interferograms to obtain the desired phase correction. Airborne single-pass interferometric data from the Deutsches Zentrum fuer Luft- und Raumfahrt (DLR) experimental airborne SAR is used to validate the method. @Article{pratsMallorqui03ESAR, author = {Prats, Pau and Mallorqui, Jordi J.}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {{Estimation of azimuth phase undulations with multisquint processing in airborne interferometric SAR images}}, year = {2003}, number = {6}, pages = {1530-1533}, volume = {41}, abstract = {Presents a technique to detect and correct phase errors appearing in interferometric airborne synthetic aperture radar (SAR) systems due to the lack of precision in the navigation system. The technique is based on a multisquint processing approach, i.e. by processing the same image pairs with different squint angles we can combine the information of different interferograms to obtain the desired phase correction. Airborne single-pass interferometric data from the Deutsches Zentrum fuer Luft- und Raumfahrt (DLR) experimental airborne SAR is used to validate the method.}, file = {:pratsMallorqui03ESAR.pdf:PDF}, keywords = {SAR Processing, Squinted SAR, airborne radar, radar imaging, synthetic aperture radar, ESAR, DLR experimental airborne SAR, Germany, Oberpfaffenhofen test site, azimuth phase undulations, calibration, image pairs, interferometric airborne synthetic aperture radar systems, multisquint processing, phase error correction, phase error detection, single-pass interferometrie data, squint angles, technique, InSAR, Interferometry}, owner = {ofrey}, pdf = {../../../docs/pratsMallorqui03.pdf}, url = {http://ieeexplore.ieee.org/iel5/36/27418/01220264.pdf}, } -
A. Reigber and R. Scheiber.
Airborne differential SAR interferometry: first results at L-band.
IEEE Trans. Geosci. Remote Sens.,
41(6):1516-1520,
2003.
Keyword(s): SAR Processing,
airborne radar,
radiowave interferometry,
remote sensing by radar,
synthetic aperture radar,
vegetation mapping,
Earth surface,
Germany,
L-Band,
Oberpfaffenhofen test site,
agricultural areas,
airborne differential SAR interferometry,
airborne sensors,
atmospheric effects,
centimetre-scale deformations,
critical region monitoring,
data acquisition intervals,
forested areas,
glacier flows,
interferometric repeat-pass mode,
landslides,
long-term decorrelation,
motion compensation,
motion errors,
phase artifacts,
ESAR,
Motion Compensation,
Interferometric SAR,
Interferometry,
D-InSAR.
Abstract: In recent years, differential interferometry using spaceborne synthetic aperture radar (SAR) sensors has become an established technique for detecting and monitoring centimetre-scale deformations of the Earth's surface, as well as glacier flows and landslides. Although often very efficient, the use of spaceborne SAR data has several drawbacks, namely phase artifacts caused by atmospheric effects and very low coherence due to long data acquisition intervals and the short radar wavelength of the sensor. Most important, current spaceborne sensors are not able to ensure flexible monitoring of critical regions. Airborne sensors may overcome most of the problems mentioned above, but up to now, the operational use of airborne differential SAR interferometry has been prevented by insufficiently accurate motion compensation of the platform. In this letter, first results of airborne differential interferometry using the German Aerospace Center (DLR) experimental SAR system (E-SAR) in the interferometric repeat-pass mode are addressed. This includes an analysis of long-term decorrelation behavior in L-band and, particularly, the correction of residual motion errors in heavily decorrelated interferograms. A first differential interferogram of agricultural and forested areas is presented and analyzed. @Article{reigberScheiber03:DiffSARLBand, author = {Reigber, A. and Scheiber, R.}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {Airborne differential {SAR} interferometry: first results at {L-}band}, year = {2003}, number = {6}, pages = {1516--1520}, volume = {41}, abstract = {In recent years, differential interferometry using spaceborne synthetic aperture radar (SAR) sensors has become an established technique for detecting and monitoring centimetre-scale deformations of the Earth's surface, as well as glacier flows and landslides. Although often very efficient, the use of spaceborne SAR data has several drawbacks, namely phase artifacts caused by atmospheric effects and very low coherence due to long data acquisition intervals and the short radar wavelength of the sensor. Most important, current spaceborne sensors are not able to ensure flexible monitoring of critical regions. Airborne sensors may overcome most of the problems mentioned above, but up to now, the operational use of airborne differential SAR interferometry has been prevented by insufficiently accurate motion compensation of the platform. In this letter, first results of airborne differential interferometry using the German Aerospace Center (DLR) experimental SAR system (E-SAR) in the interferometric repeat-pass mode are addressed. This includes an analysis of long-term decorrelation behavior in L-band and, particularly, the correction of residual motion errors in heavily decorrelated interferograms. A first differential interferogram of agricultural and forested areas is presented and analyzed.}, keywords = {SAR Processing, airborne radar, radiowave interferometry, remote sensing by radar, synthetic aperture radar, vegetation mapping, Earth surface, Germany, L-Band, Oberpfaffenhofen test site, agricultural areas, airborne differential SAR interferometry, airborne sensors, atmospheric effects, centimetre-scale deformations, critical region monitoring, data acquisition intervals, forested areas, glacier flows, interferometric repeat-pass mode, landslides, long-term decorrelation, motion compensation, motion errors, phase artifacts, ESAR, Motion Compensation, Interferometric SAR, Interferometry, D-InSAR}, owner = {ofrey}, pdf = {../../../docs/reigberScheiber03.pdf}, url = {http://ieeexplore.ieee.org/iel5/36/27418/01220261.pdf}, } -
David A. Schmidt and Roland Bürgmann.
Time-dependent land uplift and subsidence in the Santa Clara valley, California, from a large interferometric synthetic aperture radar data set.
J. Geophys. Res.,
108(B9):2416,
September 2003.
Keyword(s): SAR Processing,
PSI,
Persistent Scatterer Interferometry,
Interferometry,
SAR Interferometry,
InSAR,
Differential SAR Interferometry,
DInSAR,
Groundwater hydrology,
Water supply,
Physical Properties of Rocks,
Permeability and porosity,
Space geodetic surveys.
Abstract: We invert 115 differential interferograms derived from 47 synthetic aperture radar (SAR) scenes for a time-dependent deformation signal in the Santa Clara valley, California. The time-dependent deformation is calculated by performing a linear inversion that solves for the incremental range change between SAR scene acquisitions. A nonlinear range change signal is extracted from the ERS InSAR data without imposing a model of the expected deformation. In the Santa Clara valley, cumulative land uplift is observed during the period from 1992 to 2000 with a maximum uplift of 41 +/- 18 mm centered north of Sunnyvale. Uplift is also observed east of San Jose. Seasonal uplift and subsidence dominate west of the Silver Creek fault near San Jose with a maximum peak-to-trough amplitude of approx. 35 mm. The pattern of seasonal versus long-term uplift provides constraints on the spatial and temporal characteristics of water-bearing units within the aquifer. The Silver Creek fault partitions the uplift behavior of the basin, suggesting that it acts as a hydrologic barrier to groundwater flow. While no tectonic creep is observed along the fault, the development of a low-permeability barrier that bisects the alluvium suggests that the fault has been active since the deposition of Quaternary units. @Article{schmidtBuergmann2003JGR_PSI, author = {Schmidt, David A. and B{\"u}rgmann, Roland}, title = {Time-dependent land uplift and subsidence in the {S}anta {C}lara valley, {C}alifornia, from a large interferometric synthetic aperture radar data set}, journal = {J. Geophys. Res.}, year = {2003}, volume = {108}, number = {B9}, pages = {2416}, month = sep, issn = {0148-0227}, abstract = {We invert 115 differential interferograms derived from 47 synthetic aperture radar (SAR) scenes for a time-dependent deformation signal in the Santa Clara valley, California. The time-dependent deformation is calculated by performing a linear inversion that solves for the incremental range change between SAR scene acquisitions. A nonlinear range change signal is extracted from the ERS InSAR data without imposing a model of the expected deformation. In the Santa Clara valley, cumulative land uplift is observed during the period from 1992 to 2000 with a maximum uplift of 41 +/- 18 mm centered north of Sunnyvale. Uplift is also observed east of San Jose. Seasonal uplift and subsidence dominate west of the Silver Creek fault near San Jose with a maximum peak-to-trough amplitude of approx. 35 mm. The pattern of seasonal versus long-term uplift provides constraints on the spatial and temporal characteristics of water-bearing units within the aquifer. The Silver Creek fault partitions the uplift behavior of the basin, suggesting that it acts as a hydrologic barrier to groundwater flow. While no tectonic creep is observed along the fault, the development of a low-permeability barrier that bisects the alluvium suggests that the fault has been active since the deposition of Quaternary units.}, file = {:schmidtBuergmann2003JGR_PSI.pdf:PDF}, keywords = {SAR Processing, PSI, Persistent Scatterer Interferometry, Interferometry, SAR Interferometry, InSAR, Differential SAR Interferometry, DInSAR, Groundwater hydrology, Water supply, Physical Properties of Rocks, Permeability and porosity, Space geodetic surveys}, owner = {ofrey}, pdf = {../../../docs/schmidtBuergmann2003JGR_PSI.pdf}, publisher = {AGU}, url = {http://dx.doi.org/10.1029/2002JB002267}, } -
Jean-Claude Souyris,
Caroline Henry,
and Frédéric Adragna.
On the use of complex SAR image spectral analysis for target detection: assessment of polarimetry.
IEEE Trans. Geosci. Remote Sens.,
41(12):2725-2734,
December 2003.
Keyword(s): SAR Processing,
Interferometry,
SAR Interferometry,
Persistent Scatterer Interferometry,
PSI,
Interferometric Point Target Analysis,
IPTA,
Spectral coherence,
Selection of point target candidates,
radar detection,
radar imaging,
radar polarimetry,
remote sensing by radar,
spectral analysis,
synthetic aperture radar,
2L-HIP derivation,
azimuth,
clutter,
complex SAR image spectral analysis,
magnitude,
phase,
point target detection,
polarimetry,
range spectra,
synthetic aperture radar polarimetric image,
target detection,
two-looks internal Hermitian product,
Azimuth,
Image analysis,
Object detection,
Polarization,
Radar clutter,
Radar imaging,
Radar polarimetry,
Speckle,
Spectral analysis,
Synthetic aperture radar.
Abstract: The objective of this paper is to assess the joint use of the magnitude and the phase of a synthetic aperture radar (SAR) polarimetric image for point target detection and analysis. We first consider a single-look complex (SLC), single polarized radar image including point targets embedded in clutter. A series of sublooks are generated from this SLC image, both in azimuth and in range in order to analyze the inherent speckle effects. The two-looks internal Hermitian product (2L-IHP) is defined and is further shown to qualitatively increase the target/environment contrast. The processing of azimuth and range spectra preliminary to the 2L-IHP derivation (spectral whitening, generation and overlapping of sublooks) is described. A simulation tool is developed to model a point target behavior. Then, the polarimetric extension of the 2L-IHP is proposed, and the optimized polarimetric 2L-IHP is defined. The gain is twofold: in comparison with single polarization, polarimetry is shown to enhance detection capabilities, but also to provide additional information for target analysis. @Article{souyrisHenryAdragnaTGRS2003, author = {Souyris, Jean-Claude and Henry, Caroline and Adragna, Fr{\'e}d{\'e}ric}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {On the use of complex {SAR} image spectral analysis for target detection: assessment of polarimetry}, year = {2003}, issn = {0196-2892}, month = dec, number = {12}, pages = {2725-2734}, volume = {41}, abstract = {The objective of this paper is to assess the joint use of the magnitude and the phase of a synthetic aperture radar (SAR) polarimetric image for point target detection and analysis. We first consider a single-look complex (SLC), single polarized radar image including point targets embedded in clutter. A series of sublooks are generated from this SLC image, both in azimuth and in range in order to analyze the inherent speckle effects. The two-looks internal Hermitian product (2L-IHP) is defined and is further shown to qualitatively increase the target/environment contrast. The processing of azimuth and range spectra preliminary to the 2L-IHP derivation (spectral whitening, generation and overlapping of sublooks) is described. A simulation tool is developed to model a point target behavior. Then, the polarimetric extension of the 2L-IHP is proposed, and the optimized polarimetric 2L-IHP is defined. The gain is twofold: in comparison with single polarization, polarimetry is shown to enhance detection capabilities, but also to provide additional information for target analysis.}, doi = {10.1109/TGRS.2003.817809}, file = {:souyrisHenryAdragnaTGRS2003SpectralCoherence.pdf:PDF}, keywords = {SAR Processing, Interferometry, SAR Interferometry, Persistent Scatterer Interferometry, PSI, Interferometric Point Target Analysis, IPTA, Spectral coherence, Selection of point target candidates, radar detection;radar imaging;radar polarimetry;remote sensing by radar;spectral analysis;synthetic aperture radar;2L-HIP derivation;azimuth;clutter;complex SAR image spectral analysis;magnitude;phase;point target detection;polarimetry;range spectra;synthetic aperture radar polarimetric image;target detection;two-looks internal Hermitian product;Azimuth;Image analysis;Object detection;Polarization;Radar clutter;Radar imaging;Radar polarimetry;Speckle;Spectral analysis;Synthetic aperture radar}, pdf = {../../../docs/souyrisHenryAdragnaTGRS2003.pdf}, } -
Petre Stoica,
Zhisong Wang,
and Jian Li.
Robust Capon beamforming.
IEEE Signal Processing Letters,
10(6):172-175,
June 2003.
Keyword(s): SAR Processing,
Capon,
Capon Beamforming,
Robust Capon beamforming,
Beamforming,
Spectral Estimation,
array signal processing,
interference suppression,
signal resolution adaptive arrays,
adaptive beamforming,
array steering vector,
interference rejection capability,
resolution,
signal of interest,
uncertain steering vectors.
Abstract: The Capon beamformer has better resolution and much better interference rejection capability than the standard (data-independent) beamformer, provided that the array steering vector corresponding to the signal of interest (SOI) is accurately known. However, whenever the knowledge of the SOI steering vector is imprecise (as is often the case in practice), the performance of the Capon beamformer may become worse than that of the standard beamformer. We present a natural extension of the Capon beamformer to the case of uncertain steering vectors. The proposed robust Capon beamformer can no longer be expressed in a closed form, but it can be efficiently computed. Its excellent performance is demonstrated via a number of numerical examples. @Article{stoicaWangLi2003:Capon, Title = {Robust Capon beamforming}, Author = {Stoica, Petre and Zhisong Wang and Jian Li}, Doi = {10.1109/LSP.2003.811637}, ISSN = {1558-2361}, Month = {jun}, Number = {6}, Pages = {172--175}, Url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1198667&isnumber=26980}, Volume = {10}, Year = {2003}, Abstract = {The Capon beamformer has better resolution and much better interference rejection capability than the standard (data-independent) beamformer, provided that the array steering vector corresponding to the signal of interest (SOI) is accurately known. However, whenever the knowledge of the SOI steering vector is imprecise (as is often the case in practice), the performance of the Capon beamformer may become worse than that of the standard beamformer. We present a natural extension of the Capon beamformer to the case of uncertain steering vectors. The proposed robust Capon beamformer can no longer be expressed in a closed form, but it can be efficiently computed. Its excellent performance is demonstrated via a number of numerical examples.}, Journal = {IEEE Signal Processing Letters}, Keywords = {SAR Processing, Capon, Capon Beamforming, Robust Capon beamforming, Beamforming, Spectral Estimation, array signal processing, interference suppression, signal resolution adaptive arrays, adaptive beamforming, array steering vector, interference rejection capability, resolution, signal of interest, uncertain steering vectors}, Owner = {ofrey}, Pdf = {../../../docs/stoicaWangLi2003.pdf} } -
Tazio Strozzi,
Urs Wegmuller,
Charles L Werner,
Andreas Wiesmann,
and Volker Spreckels.
JERS SAR interferometry for land subsidence monitoring.
IEEE Trans. Geosci. Remot Sens.,
41(7):1702-1708,
2003.
Keyword(s): SAR Processing,
SAR Interferometry,
Interferometry.
@Article{strozziWegmullerWernerWiesmannSpreckelsTGRS2003JERSInSARSubsidence, author = {Strozzi, Tazio and Wegmuller, Urs and Werner, Charles L and Wiesmann, Andreas and Spreckels, Volker}, journal = {IEEE Trans. Geosci. Remot Sens.}, title = {{JERS} {SAR} interferometry for land subsidence monitoring}, year = {2003}, number = {7}, pages = {1702--1708}, volume = {41}, doi = {10.1109/TGRS.2003.813273}, file = {:strozziWegmullerWernerWiesmannSpreckelsTGRS2003JERSInSARSubsidence.pdf:PDF}, keywords = {SAR Processing, SAR Interferometry, Interferometry}, owner = {ofrey}, publisher = {IEEE}, } -
Dario Tarchi,
Nicola Casagli,
Sandro Moretti,
Davide Leva,
and Alois J. Sieber.
Monitoring landslide displacements by using ground-based synthetic aperture radar interferometry: Application to the Ruinon landslide in the Italian Alps.
Journal of Geophysical Research: Solid Earth,
108(B8),
2003.
Note: 2387.
Keyword(s): GBSAR,
SAR Processing,
Ground-based SAR,
Synthetic aperture radar,
SAR interferometry,
differential SAR interferometry,
DInSAR,
interferometric stacking,
deformation monitoring,
subsidence monitoring,
deformation measurements,
Electromagnetics: Instrumentation and techniques,
Control surveys,
Geomorphology: general,
Geomorphology: fluvial,
Geomorphology: hillslope,
Instruments and techniques: modeling,
Instruments and techniques: monitoring,
General or Miscellaneous: New fields (not classifiable under other headings),
remote sensing,
interferometry,
radar,
landslide,
monitoring,
ground-based DInSAR.
@Article{tarchiCasagliMorettiLevaSieberJGRB2003GBSARLISAJRC, author = {Tarchi, Dario and Casagli, Nicola and Moretti, Sandro and Leva, Davide and Sieber, Alois J.}, journal = {Journal of Geophysical Research: Solid Earth}, title = {Monitoring landslide displacements by using ground-based synthetic aperture radar interferometry: Application to the {R}uinon landslide in the {I}talian {A}lps}, year = {2003}, issn = {2156-2202}, note = {2387}, number = {B8}, volume = {108}, doi = {10.1029/2002JB002204}, file = {:tarchiCasagliMorettiLevaSieberJGRB2003GBSARLISAJRC.pdf:PDF}, keywords = {GBSAR, SAR Processing, Ground-based SAR, Synthetic aperture radar, SAR interferometry, differential SAR interferometry, DInSAR, interferometric stacking, deformation monitoring, subsidence monitoring, deformation measurements, Electromagnetics: Instrumentation and techniques, Control surveys, Geomorphology: general, Geomorphology: fluvial, Geomorphology: hillslope, Instruments and techniques: modeling, Instruments and techniques: monitoring, General or Miscellaneous: New fields (not classifiable under other headings), remote sensing, interferometry, radar, landslide, monitoring, ground-based DInSAR}, pdf = {../../../docs/tarchiCasagliMorettiLevaSieberJGRB2003GBSARLISAJRC.pdf}, url = {http://dx.doi.org/10.1029/2002JB002204}, } -
G. Tavernier,
J. P. Granier,
C. Jayles,
P. Sengenes,
and F. Rozo.
The current evolutions of the DORIS system.
Advances in Space Research,
31(8):1947-1952,
2003.
Keyword(s): DORIS,
Orbit,
Precise Orbit,
Accuracy,
ENVISAT,
ASAR.
Abstract: DORIS was developed for precise orbit determination and precise positioning on Earth. Three new satellites fitted out with dual-channel second-generation receivers have been recently launched. Jason-1, ENVISAT and SPOT-5 acquired a real autonomy thanks to DIODE real time on-board orbit determination software. Today the DORIS system has built up a global network of 55 stations. In order to reach new accuracy goals for Jason-1 and ENVISAT, it was decided to improve the long-term stability of the antennas when necessary. Third-generation beacons deployed from the end of 2001 offer new features and greater reliability. The satellites relay acquired and stored data at regular intervals to SSALTO, the new DORIS mission control center. DORIS data from the different satellites are currently available in the two Data Centers and used by the International DORIS Service Analysis groups. @Article{tavernierGranierJaylesSengenesRozo03:DORIS, author = {Tavernier, G. and Granier, J. P. and Jayles, C. and Sengenes, P. and Rozo, F.}, journal = {Advances in Space Research}, title = {The current evolutions of the DORIS system}, year = {2003}, number = {8}, pages = {1947--1952}, volume = {31}, abstract = {DORIS was developed for precise orbit determination and precise positioning on Earth. Three new satellites fitted out with dual-channel second-generation receivers have been recently launched. Jason-1, ENVISAT and SPOT-5 acquired a real autonomy thanks to DIODE real time on-board orbit determination software. Today the DORIS system has built up a global network of 55 stations. In order to reach new accuracy goals for Jason-1 and ENVISAT, it was decided to improve the long-term stability of the antennas when necessary. Third-generation beacons deployed from the end of 2001 offer new features and greater reliability. The satellites relay acquired and stored data at regular intervals to SSALTO, the new DORIS mission control center. DORIS data from the different satellites are currently available in the two Data Centers and used by the International DORIS Service Analysis groups.}, keywords = {DORIS, Orbit, Precise Orbit, Accuracy, ENVISAT, ASAR}, owner = {ofrey}, pdf = {../../../docs/tavernierGranierJaylesSengenesRozo03.pdf}, url = {http://www.sciencedirect.com/science/article/B6V3S-49WCJGJ-H/2/b721d4e63f917fc485e9ef8762e61a57}, } -
Lars M. H. Ulander,
Hans Hellsten,
and Gunnar Stenström.
Synthetic-Aperture Radar Processing Using Fast Factorized Back-Projection.
IEEE Transactions on Aerospace and Electronic Systems,
39(3):760-776,
July 2003.
Keyword(s): SAR Processing,
Fast Factorized Back-Projection,
Time-Domain Back-Projection,
TDBP,
Back-Projection,
Fast Back-Projection,
Factorized Back-Projection,
Ultra-Wideband SAR,
VHF SAR,
CARABAS,
Airborne SAR.
Abstract: Exact synthetic aperture radar (SAR) inversion for a linear aperture may be obtained using fast transform techniques. Alternatively, back-projection integration in time domain can also be used. This technique has the benefit of handling a general aperture geometry. In the past, however, back-projection has seldom been used due to heavy computational burden. We show that the back-projection integral can be recursively partitioned and an effective algorithm constructed based on aperture factorization. By representing images in local polar coordinates it is shown that the number of operations is drastically reduced and can be made to approach that of fast transform algorithms. The algorithm is applied to data from the airborne ultra-wideband CARABAS SAR and shown to give a reduction in processing time of two to three orders of magnitude. @Article{ulanHellSten:FastBackpro, author = {Lars M. H. Ulander and Hans Hellsten and Gunnar Stenstr{\"o}m}, journal = {IEEE Transactions on Aerospace and Electronic Systems}, title = {{Synthetic-Aperture Radar Processing Using Fast Factorized Back-Projection}}, year = {2003}, month = Jul, number = {3}, pages = {760-776}, volume = {39}, abstract = {Exact synthetic aperture radar (SAR) inversion for a linear aperture may be obtained using fast transform techniques. Alternatively, back-projection integration in time domain can also be used. This technique has the benefit of handling a general aperture geometry. In the past, however, back-projection has seldom been used due to heavy computational burden. We show that the back-projection integral can be recursively partitioned and an effective algorithm constructed based on aperture factorization. By representing images in local polar coordinates it is shown that the number of operations is drastically reduced and can be made to approach that of fast transform algorithms. The algorithm is applied to data from the airborne ultra-wideband CARABAS SAR and shown to give a reduction in processing time of two to three orders of magnitude.}, doi = {10.1109/TAES.2003.1238734}, file = {:ulanderHellstenStenstrom03.pdf:PDF}, keywords = {SAR Processing, Fast Factorized Back-Projection, Time-Domain Back-Projection, TDBP, Back-Projection, Fast Back-Projection, Factorized Back-Projection, Ultra-Wideband SAR, VHF SAR, CARABAS, Airborne SAR}, pdf = {../../../docs/ulanderHellstenStenstrom03.pdf}, url = {http://ieeexplore.ieee.org/iel5/7/27785/01238734.pdf}, } -
Marwan Younis,
Christian Fischer,
and Werner Wiesbeck.
Digital beamforming in SAR systems.
IEEE Trans. Geosci. Remote Sens.,
41(7):1735-1739,
July 2003.
Keyword(s): SAR,
digital beamforming,
digital hardware,
digital interface,
geophysical measurement technique,
land surface,
radar remote sensing,
signal processing,
software codes,
software-defined radar sensors,
synthetic aperture radar,
terrain mapping,
geophysical signal processing,
geophysical techniques,
radar signal processing,
remote sensing by radar,
synthetic aperture radar,
terrain mapping.
Abstract: The rapid progression in digital hardware and signal processing capabilities stimulates the development of radar systems. The tendency is to move the digital interface toward the antenna, replacing, whenever possible, analog RF-hardware. Based on software codes, these digital systems are more flexible and easier to reconfigure than RF-hardware. This letter illustrates the general concept for digital beamforming (DBF) in synthetic aperture radar systems and investigates their principle capabilities, limitations, and performance parameters. It is shown that using DBF a simultaneous improvement in azimuth coverage and resolution can be achieved. @Article{younisFischerWiesbeck2003DBF, author = {Younis, Marwan and Fischer, Christian and Wiesbeck, Werner}, journal = {IEEE Trans. Geosci. Remote Sens.}, title = {Digital beamforming in {SAR} systems}, year = {2003}, issn = {0196-2892}, month = jul, number = {7}, pages = {1735-1739}, volume = {41}, abstract = {The rapid progression in digital hardware and signal processing capabilities stimulates the development of radar systems. The tendency is to move the digital interface toward the antenna, replacing, whenever possible, analog RF-hardware. Based on software codes, these digital systems are more flexible and easier to reconfigure than RF-hardware. This letter illustrates the general concept for digital beamforming (DBF) in synthetic aperture radar systems and investigates their principle capabilities, limitations, and performance parameters. It is shown that using DBF a simultaneous improvement in azimuth coverage and resolution can be achieved.}, doi = {10.1109/TGRS.2003.815662}, file = {:younisFischerWiesbeck2003DBF.pdf:PDF}, keywords = {SAR; digital beamforming; digital hardware; digital interface; geophysical measurement technique; land surface; radar remote sensing; signal processing; software codes; software-defined radar sensors; synthetic aperture radar; terrain mapping; geophysical signal processing; geophysical techniques; radar signal processing; remote sensing by radar; synthetic aperture radar; terrain mapping}, owner = {ofrey}, pdf = {../../../docs/younisFischerWiesbeck2003DBF.pdf}, }
Conference articles
-
Nico Adam,
Bert M. Kampes,
Michael Eineder,
Jirathana Worawattanamateekul,
and Michaela Kircher.
The Development of a Scientific Permanent Scatterer System.
In ISPRS Workshop High Resolution Mapping from Space,
Hannover, Germany,
pages 1-6,
2003.
Keyword(s): SAR Processing,
SAR Interferometry,
D-InSAR,
Differential SAR Interferometry,
Persistent Scatterer Interferometry,
PSI,
Deformation measurement,
Displacement measurement.
@InProceedings{adamEtAl2003ScientificPSISystem, author = {Nico Adam and Bert M. Kampes and Michael Eineder and Jirathana Worawattanamateekul and Michaela Kircher}, title = {The Development of a Scientific Permanent Scatterer System}, booktitle = {ISPRS Workshop High Resolution Mapping from Space}, year = {2003}, pages = {1-6}, address = {Hannover, Germany}, keywords = {SAR Processing, SAR Interferometry, D-InSAR, Differential SAR Interferometry, Persistent Scatterer Interferometry, PSI, Deformation measurement, Displacement measurement}, owner = {ofrey}, } -
W. - M. Boerner.
Recent Advances in Extra-Wide-Band Polarimetry, Interferometry and Polarimetric Interferometry in Synthetic Aperture Remote Sensing and its Applications.
In IEE Proceedings - Radar, Sonar and Navigation,
volume 150,
pages 113-124,
June 2003.
Keyword(s): SAR Processing,
Interferometry,
Pol-InSAR,
RFI Suppression,
Extra-WideBand SAR,
WideBand SAR.
Abstract: The development of radar polarimetry and radar interferometry is advancing rapidly, and these novel radar technologies are revamping 'synthetic aperture radar imaging' decisively. The successive advancements are sketched beginning with the fundamental formulations and highlighting the salient points of these diverse remote sensing techniques. Whereas with radar polarimetry the textural fine-structure, target orientation and shape, symmetries and material constituents can be recovered with considerable improvements above that of standard 'amplitude-only polarisation radar'; with radar interferometry the spatial (in depth) structure can be explored. In 'polarimetric-interferometric synthetic aperture radar (POL-IN-SAR) imaging' it is possible to recover such co-registered textural plus spatial properties simultaneously. This includes the extraction of 'digital elevation maps (DEM)' from either 'fully polarimetric (scattering matrix)' or 'interferometric (dual antenna) SAR image data takes' with the additional benefit of obtaining co-registered three-dimensional 'POL-IN-DEM' information. Extra-wide-band POL-IN-SAR imaging - when applied to 'repeat-pass image overlay interferometry' - provides differential background validation and measurement, stress assessment, and environmental stress-change monitoring capabilities with hitherto unattained accuracy, which are essential tools for improved global biomass estimation and also for wetland assessment and monitoring. More recently, by applying multiple parallel repeat-pass EWB-POL-D(RP)-IN-SAR imaging along stacked (altitudinal) or displaced (horizontal) flight-lines will result in 'tomographic (multi-interferometric) polarimetric SAR stereo-imaging', including foliage- and ground-penetrating capabilities. In addition, various closely related topics of (i) acquiring additional and protecting existing spectral windows of the 'natural electromagnetic spectrum (NES)' pertinent to remote sensing; and (ii) mitigation against common 'radio frequency interference (RFI)' and intentional 'directive jamming of airborne and spaceborne POL-IN-SAR imaging platforms' are appraised. @InProceedings{Boerner03:EWB, Title = {{Recent Advances in Extra-Wide-Band Polarimetry, Interferometry and Polarimetric Interferometry in Synthetic Aperture Remote Sensing and its Applications}}, Author = {W. - M. Boerner}, Booktitle = {IEE Proceedings - Radar, Sonar and Navigation}, Month = Jun, Number = {3}, Pages = {113-124}, Url = {http://ieeexplore.ieee.org/iel5/2198/27458/01222371.pdf}, Volume = {150}, Year = {2003}, Abstract = {The development of radar polarimetry and radar interferometry is advancing rapidly, and these novel radar technologies are revamping 'synthetic aperture radar imaging' decisively. The successive advancements are sketched beginning with the fundamental formulations and highlighting the salient points of these diverse remote sensing techniques. Whereas with radar polarimetry the textural fine-structure, target orientation and shape, symmetries and material constituents can be recovered with considerable improvements above that of standard 'amplitude-only polarisation radar'; with radar interferometry the spatial (in depth) structure can be explored. In 'polarimetric-interferometric synthetic aperture radar (POL-IN-SAR) imaging' it is possible to recover such co-registered textural plus spatial properties simultaneously. This includes the extraction of 'digital elevation maps (DEM)' from either 'fully polarimetric (scattering matrix)' or 'interferometric (dual antenna) SAR image data takes' with the additional benefit of obtaining co-registered three-dimensional 'POL-IN-DEM' information. Extra-wide-band POL-IN-SAR imaging - when applied to 'repeat-pass image overlay interferometry' - provides differential background validation and measurement, stress assessment, and environmental stress-change monitoring capabilities with hitherto unattained accuracy, which are essential tools for improved global biomass estimation and also for wetland assessment and monitoring. More recently, by applying multiple parallel repeat-pass EWB-POL-D(RP)-IN-SAR imaging along stacked (altitudinal) or displaced (horizontal) flight-lines will result in 'tomographic (multi-interferometric) polarimetric SAR stereo-imaging', including foliage- and ground-penetrating capabilities. In addition, various closely related topics of (i) acquiring additional and protecting existing spectral windows of the 'natural electromagnetic spectrum (NES)' pertinent to remote sensing; and (ii) mitigation against common 'radio frequency interference (RFI)' and intentional 'directive jamming of airborne and spaceborne POL-IN-SAR imaging platforms' are appraised.}, Keywords = {SAR Processing, Interferometry, Pol-InSAR, RFI Suppression, Extra-WideBand SAR, WideBand SAR}, Pdf = {../../../docs/Boerner03.pdf} } -
H.J. Callow,
M.P. Hayes,
and P.T. Gough.
Autofocus of stripmap SAS data using the range-variant SPGA algorithm.
In OCEANS 2003 Proceedings,
volume 5,
pages 2422-2426,
September 2003.
Keyword(s): SAR Processing,
Autofocus,
Phase Curvature Autofocus,
Phase Gradient Autofocus,
PGA,
SPGA,
Stripmap Phase Gradient Algorithm,
Synthetic Aperture Sonar,
SAS.
@InProceedings{Callow2003a, Title = {Autofocus of stripmap {SAS} data using the range-variant {SPGA} algorithm}, Author = {Callow, H.J. and Hayes, M.P. and Gough, P.T.}, Booktitle = {OCEANS 2003 Proceedings}, Month = sep, Pages = {2422--2426}, Volume = {5}, Year = {2003}, Keywords = {SAR Processing, Autofocus, Phase Curvature Autofocus, Phase Gradient Autofocus, PGA, SPGA, Stripmap Phase Gradient Algorithm, Synthetic Aperture Sonar, SAS}, Owner = {ofrey} } -
H.J. Callow,
M.P. Hayes,
and P.T. Gough.
Stripmap phase gradient autofocus.
In OCEANS 2003. Proceedings,
volume 5,
pages 2414-2421,
September 2003.
Keyword(s): SAR Processing,
Autofocus,
Phase Curvature Autofocus,
Phase Gradient Autofocus,
PGA,
SPGA,
Stripmap Phase Gradient Algorithm,
Synthetic Aperture Sonar,
SAS.
Abstract: Current sonar autofocus techniques for blur removal originate in the radar community but have not provided a complete solution for Synthetic Aperture Sonar (SAS) imagery. The wide-beam, wide-band nature of SAS imagery makes implementation of Synthetic Aperture Radar (SAR) autofocus techniques difficult. This paper describes a generalisation of the standard Phase Gradient Antofocus (PGA) algorithm used in spotlight SAR that allows operation with stripmap SAS geometries. PGA uses prominent points within the target scene to estimate image blurring and phase errors. We show how PGA can be generalised to work with wide-band, wide-heam stripmap geometries. The SPGA method works by employing wavenumher domain 2D phase estimation techniques. The 2D phase errors are related to aperture position errors using the wavenumber transform. Robust sway estimates are obtained by using redundancy over a number of target points. We also present an improved Phase Curvature Autofocus (PCA) algorithm using the wavenumher transform. Preliminary results from the two algorithms (both on field-collected and simulated data sets) are presented and related to those obtained using previous methods. A discussion of SPGA's benefits over traditional algorithms and the limitations of the SPGA algorithm. The SPGA algorithm was found to perform better than 2-D PCA on both simulated and field-collected data sets. Further testing on a variety of target scenes and imagery is required to investigate avenues of autofoeus improvement. @InProceedings{Callow2003, author = {Callow, H.J. and Hayes, M.P. and Gough, P.T.}, title = {Stripmap phase gradient autofocus}, booktitle = {OCEANS 2003. Proceedings}, year = {2003}, volume = {5}, pages = {2414--2421}, month = {sep}, abstract = {Current sonar autofocus techniques for blur removal originate in the radar community but have not provided a complete solution for Synthetic Aperture Sonar (SAS) imagery. The wide-beam, wide-band nature of SAS imagery makes implementation of Synthetic Aperture Radar (SAR) autofocus techniques difficult. This paper describes a generalisation of the standard Phase Gradient Antofocus (PGA) algorithm used in spotlight SAR that allows operation with stripmap SAS geometries. PGA uses prominent points within the target scene to estimate image blurring and phase errors. We show how PGA can be generalised to work with wide-band, wide-heam stripmap geometries. The SPGA method works by employing wavenumher domain 2D phase estimation techniques. The 2D phase errors are related to aperture position errors using the wavenumber transform. Robust sway estimates are obtained by using redundancy over a number of target points. We also present an improved Phase Curvature Autofocus (PCA) algorithm using the wavenumher transform. Preliminary results from the two algorithms (both on field-collected and simulated data sets) are presented and related to those obtained using previous methods. A discussion of SPGA's benefits over traditional algorithms and the limitations of the SPGA algorithm. The SPGA algorithm was found to perform better than 2-D PCA on both simulated and field-collected data sets. Further testing on a variety of target scenes and imagery is required to investigate avenues of autofoeus improvement.}, doi = {10.1109/OCEANS.2003.1282922}, file = {:Callow2003PhD.pdf:PDF}, keywords = {SAR Processing, Autofocus, Phase Curvature Autofocus, Phase Gradient Autofocus, PGA, SPGA, Stripmap Phase Gradient Algorithm, Synthetic Aperture Sonar, SAS}, owner = {ofrey}, pdf = {../../../docs/callowHayesGough2003.pdf}, } -
Hubert-M.J. Cantalloube and Pascale Dubois-Fernandez.
Airborne X-band SAR imaging with 10 cm resolution - technical challenge and preliminary results.
In ,
volume 1,
pages 185-187,
July 2003.
Keyword(s): SAR Processing,
Motion Compensation,
Autofocus,
radar cross-sections,
radar imaging,
radar resolution,
remote sensing by radar,
synthetic aperture radar 2 1/2 D surface modelling,
Doppler algorithms,
Ku bands,
RAMSES,
X-Band,
X-band SAR imaging,
Airborne SAR,
antenna pattern compensation method,
back-injection synthesis algorithm,
carrier trajectory,
clutter appearance,
differential GPS-hybridized inertial navigation unit,
high resolution clutters,
isotropic echoes,
matching cross-range resolution,
optical surface modelling,
phase tracking,
point-like echoes,
Range Migration Algorithm,
resolution cell,
synthetic aperture radar,
TDBP,
Time-Domain Back-Projection,
temporal-domain synthesis algorithm,
texture simulations,
omega-k algorithm.
Abstract: RAMSES airborne SAR system bandwith was recently increased to 1.2 GHz in X and Ku bands, yielding (unweighted) 3 dB range resolution of 11 cm. Synthesis of SAR images with matching cross-range resolution, requires long integration time thus disqualifies temporal-domain back-injection synthesis algorithm as impractically slow. The wider relative bandwidth also disqualifies simplified range/Doppler types of algorithms because the hypothesis of proportionality between Doppler and squint is no more valid. Therefore, we implemented a fast frequency-domain synthesis algorithm omega-k or range-migration algorithm) and designed a new deterministic motion and antenna pattern compensation method for it. Since the required accuracy on carrier trajectory exceeded the performance of our differential GPS-hybridized inertial navigation unit, we implemented an autofocus based on the phase tracking of several isotropic point-like echoes. Since the resolution cell is only a few wavelength wide, clutter appearance and statistics is unusual. We present here some typical examples for high resolution clutters and compare with texture simulations from optical 2 1/2 D surface modelling. @InProceedings{cantalloubeDuboisFernandez2003:HiResAutofocus, Title = {{Airborne X-band SAR imaging with 10 cm resolution - technical challenge and preliminary results}}, Author = {Cantalloube, Hubert-M.J. and Dubois-Fernandez, Pascale}, Month = {July}, Pages = {185-187}, Url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1293718&isnumber=28601}, Volume = {1}, Year = {2003}, Abstract = {RAMSES airborne SAR system bandwith was recently increased to 1.2 GHz in X and Ku bands, yielding (unweighted) 3 dB range resolution of 11 cm. Synthesis of SAR images with matching cross-range resolution, requires long integration time thus disqualifies temporal-domain back-injection synthesis algorithm as impractically slow. The wider relative bandwidth also disqualifies simplified range/Doppler types of algorithms because the hypothesis of proportionality between Doppler and squint is no more valid. Therefore, we implemented a fast frequency-domain synthesis algorithm omega-k or range-migration algorithm) and designed a new deterministic motion and antenna pattern compensation method for it. Since the required accuracy on carrier trajectory exceeded the performance of our differential GPS-hybridized inertial navigation unit, we implemented an autofocus based on the phase tracking of several isotropic point-like echoes. Since the resolution cell is only a few wavelength wide, clutter appearance and statistics is unusual. We present here some typical examples for high resolution clutters and compare with texture simulations from optical 2 1/2 D surface modelling.}, Journal = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, Keywords = {SAR Processing, Motion Compensation, Autofocus, radar cross-sections, radar imaging, radar resolution, remote sensing by radar, synthetic aperture radar 2 1/2 D surface modelling, Doppler algorithms, Ku bands, RAMSES, X-Band, X-band SAR imaging, Airborne SAR, antenna pattern compensation method, back-injection synthesis algorithm, carrier trajectory, clutter appearance, differential GPS-hybridized inertial navigation unit, high resolution clutters, isotropic echoes, matching cross-range resolution, optical surface modelling, phase tracking, point-like echoes, Range Migration Algorithm, resolution cell, synthetic aperture radar, TDBP, Time-Domain Back-Projection, temporal-domain synthesis algorithm, texture simulations, omega-k algorithm}, Owner = {ofrey}, Pdf = {../../../docs/cantalloubeDuboisFernandez2003.pdf} } -
Shane R. Cloude and Konstantinos P. Papathanassiou.
Three-stage inversion process for polarimetric SAR interferometry.
In ,
volume 150,
pages 125-134,
June 2003.
Keyword(s): SAR Processing,
decorrelation,
electromagnetic wave scattering,
inverse problems,
parameter estimation,
radar imaging,
radar polarimetry,
remote sensing by radar,
synthetic aperture radar geometrical approach,
ground topography,
interferograms,
inversion accuracy,
mean extinction estimation,
model structure,
multiple polarisation channels,
parameter estimates,
polarimetric SAR interferometry,
random canopy,
simulated vector coherent SAR data,
single frequency sensor,
temporal decorrelation,
three-stage inversion process,
two-layer coherent scattering model,
vegetation height,
vertical tree structure.
Abstract: The authors provide a new geometrical approach for the inversion of a two-layer coherent scattering model, widely used for the interpretation of polarimetric interferometric SAR data. It has been shown in several recent publications that, by using interferograms in multiple polarisation channels, estimation of vegetation height, underlying ground topography and mean extinction is possible. Furthermore, this can be achieved with a single frequency sensor without the need for a separate reference DEM, other a priori information or the use of data-specific regression formulas. The authors first review the details of this approach and then develop a three-stage inversion procedure to illustrate the steps involved in parameter estimation. They then consider several possible sources of error in the inversion. In particular, they concentrate on the effects of vertical tree structure and on the effects of temporal decorrelation on inversion accuracy. It is shown that the former leads to errors, mainly in the extinction estimation, while the latter does not change the model structure but reduces the available parameter set and increases the variance of the parameter estimates. Finally, the new algorithm is applied to simulated vector coherent SAR data for a random canopy. @InProceedings{cloudePapathanassiou2003:3StageInversionPolInSAR, author = {Cloude, Shane R. and Papathanassiou, Konstantinos P.}, title = {Three-stage inversion process for polarimetric SAR interferometry}, year = {2003}, month = jun, number = {3}, pages = {125-134}, volume = {150}, abstract = {The authors provide a new geometrical approach for the inversion of a two-layer coherent scattering model, widely used for the interpretation of polarimetric interferometric SAR data. It has been shown in several recent publications that, by using interferograms in multiple polarisation channels, estimation of vegetation height, underlying ground topography and mean extinction is possible. Furthermore, this can be achieved with a single frequency sensor without the need for a separate reference DEM, other a priori information or the use of data-specific regression formulas. The authors first review the details of this approach and then develop a three-stage inversion procedure to illustrate the steps involved in parameter estimation. They then consider several possible sources of error in the inversion. In particular, they concentrate on the effects of vertical tree structure and on the effects of temporal decorrelation on inversion accuracy. It is shown that the former leads to errors, mainly in the extinction estimation, while the latter does not change the model structure but reduces the available parameter set and increases the variance of the parameter estimates. Finally, the new algorithm is applied to simulated vector coherent SAR data for a random canopy.}, doi = {10.1049/ip-rsn:20030449}, issn = {1350-2395}, journal = {IEE Proceedings - Radar, Sonar and Navigation}, keywords = {SAR Processing, decorrelation, electromagnetic wave scattering, inverse problems, parameter estimation, radar imaging, radar polarimetry, remote sensing by radar, synthetic aperture radar geometrical approach, ground topography, interferograms, inversion accuracy, mean extinction estimation, model structure, multiple polarisation channels, parameter estimates, polarimetric SAR interferometry, random canopy, simulated vector coherent SAR data, single frequency sensor, temporal decorrelation, three-stage inversion process, two-layer coherent scattering model, vegetation height, vertical tree structure}, owner = {ofrey}, pdf = {../../../docs/cloudePapathanassiou2003.pdf}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1222372&isnumber=27458}, } -
C. Colesanti,
A. Ferretti,
C. Prati,
and F. Rocca.
Multi-image satellite SAR interferometry: state of the art and future trends.
In Proc. Int. Radar Conf.,
pages 239-244,
September 2003.
Keyword(s): SAR Processing,
InSAR,
SAR Interferometry,
PSI,
Persistent Scatterer Interferometry,
Differential SAR Interferometry,
electromagnetic wave scattering,
radar imaging,
remote sensing by radar,
spaceborne radar,
synthetic aperture radar,
ground deformation data,
high precision elevation data,
multi-image satellite SAR interferometry,
permanent scatterers technique,
spaceborne interferometric SAR images,
sparse privileged point-wise radar target grid.
Abstract: In this paper, we wish to review briefly the principles underlying a recently developed approach, known as the permanent scatterers (PS) technique and aimed at the joint exploitation of a series of spaceborne interferometric SAR images for the retrieval of high precision elevation and ground deformation data on a sparse grid of privileged point-wise radar targets. @InProceedings{colesantiFerrettiPratiRocca2003:MBInSAR, author = {Colesanti, C. and Ferretti, A. and Prati, C. and Rocca, F.}, booktitle = {Proc. Int. Radar Conf.}, title = {Multi-image satellite {SAR} interferometry: state of the art and future trends}, year = {2003}, month = sep, pages = {239--244}, abstract = {In this paper, we wish to review briefly the principles underlying a recently developed approach, known as the permanent scatterers (PS) technique and aimed at the joint exploitation of a series of spaceborne interferometric SAR images for the retrieval of high precision elevation and ground deformation data on a sparse grid of privileged point-wise radar targets.}, doi = {10.1109/RADAR.2003.1278746}, keywords = {SAR Processing, InSAR, SAR Interferometry, PSI, Persistent Scatterer Interferometry, Differential SAR Interferometry, electromagnetic wave scattering, radar imaging, remote sensing by radar, spaceborne radar, synthetic aperture radar, ground deformation data, high precision elevation data, multi-image satellite SAR interferometry, permanent scatterers technique, spaceborne interferometric SAR images, sparse privileged point-wise radar target grid}, owner = {ofrey}, pdf = {../../../docs/colesantiFerrettiPratiRocca2003.pdf}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1278746&isnumber=28560}, } -
Ian G. Cumming,
Y. L. Neo,
and Frank Wong.
Interpretations of the Omega-K Algorithm and Comparisons with other Algorithms.
In IGARSS '03, International Geoscience and Remote Sensing Symposium,
2003.
Keyword(s): SAR Processing,
Range Migration Algorithm,
omega-k,
Wavenumber Domain Algorithm,
Stolt Mapping,
Chirp Scaling Algorithm,
Range-Doppler Algorithm,
Comparison of Algorithms.
Abstract: This paper presents a Fourier interpretation of the Omega-k SAR processing algorithm that helps explain the key Stolt mapping operation. An approximate form of the algorithm is sometimes used, and we explain how both forms of the Omega-k compare with the range Doppler and the chirp scaling algorithms. Finally, a brief discussion is given on which radar parameters allow the accurate use of each algorithm. @InProceedings{CumNeoWong:omegaK, Title = {{Interpretations of the Omega-K Algorithm and Comparisons with other Algorithms}}, Author = {Ian G. Cumming and Y. L. Neo and Frank Wong}, Booktitle = {IGARSS '03, International Geoscience and Remote Sensing Symposium}, Year = {2003}, Abstract = {This paper presents a Fourier interpretation of the Omega-k SAR processing algorithm that helps explain the key Stolt mapping operation. An approximate form of the algorithm is sometimes used, and we explain how both forms of the Omega-k compare with the range Doppler and the chirp scaling algorithms. Finally, a brief discussion is given on which radar parameters allow the accurate use of each algorithm.}, Keywords = {SAR Processing, Range Migration Algorithm, omega-k, Wavenumber Domain Algorithm, Stolt Mapping, Chirp Scaling Algorithm, Range-Doppler Algorithm, Comparison of Algorithms}, Pdf = {../../../docs/CumNeoWong03.pdf} } -
M. De Stefano and Andrea Monti-Guarnieri.
Robust Doppler Centroid estimate for ERS and ENVISAT.
In Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International,
volume 6,
pages 4062-4064,
2003.
Keyword(s): SAR Processing,
Doppler Centroid Estimation,
Doppler Ambiguity Resolver,
DAR,
ENVISAT,
ERS,
MLBF,
RADARSAT,
Wavelength Diversity,
WDAR,
Multilook Beat Frequency,
fine polynomial estimation,
higher order technique,
robust Doppler centroid estimation,
robustness,
second order statistic estimator,
unambiguous Doppler estimation.
Abstract: The algorithm presented is capable of retrieving the correct DC ambiguity and to fit a fine polynomial estimate both on uniform and contrasted scenes. The core of the algorithm exploits a block wise processing: in each block a coarse unambiguous estimate is provided by exploiting both a second order statistic estimator (WDAR) and a higher order technique (MLBF). The final, fine estimate of the unambiguous Doppler is achieved by jointly exploiting the coarse unambiguous estimate with a fine, ambiguous one. The proposed algorithm accounts carefully for large variation of DC with range, like for recent Emergency Backup Mode of ERS and RADARSAT. The final estimate and its confidence is provided by a weighted average of the block measures. Tuning of the weights and additional check ensure robustness. The estimate of the offset frequency constant is then approached and a solution for calibrating its value is provided. @InProceedings{deStefanoMontiGuarinieri03:dopCen, Title = {Robust Doppler Centroid estimate for ERS and ENVISAT}, Author = {De Stefano, M. and Monti-Guarnieri, Andrea}, Booktitle = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, Pages = {4062--4064}, Url = {http://ieeexplore.ieee.org/iel5/9010/28606/01295362.pdf}, Volume = {6}, Year = {2003}, Abstract = {The algorithm presented is capable of retrieving the correct DC ambiguity and to fit a fine polynomial estimate both on uniform and contrasted scenes. The core of the algorithm exploits a block wise processing: in each block a coarse unambiguous estimate is provided by exploiting both a second order statistic estimator (WDAR) and a higher order technique (MLBF). The final, fine estimate of the unambiguous Doppler is achieved by jointly exploiting the coarse unambiguous estimate with a fine, ambiguous one. The proposed algorithm accounts carefully for large variation of DC with range, like for recent Emergency Backup Mode of ERS and RADARSAT. The final estimate and its confidence is provided by a weighted average of the block measures. Tuning of the weights and additional check ensure robustness. The estimate of the offset frequency constant is then approached and a solution for calibrating its value is provided.}, Keywords = {SAR Processing, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, ENVISAT, ERS, MLBF, RADARSAT, Wavelength Diversity, WDAR, Multilook Beat Frequency, fine polynomial estimation, higher order technique, robust Doppler centroid estimation, robustness, second order statistic estimator, unambiguous Doppler estimation}, Owner = {ofrey}, Pdf = {../../../docs/deStefanoMontiGuarinieri03.pdf} } -
Joachim H. G. Ender.
SAR/MTI with Multi-Subaperture Phased Arrays.
In Proceedings of the Tyrrhenian International Workshop on Remote Sensing TIWRS,
pages 313-331,
September 2003.
Keyword(s): SAR,
Multi-Channel SAR,
MTI,
AER-II,
PAMIR,
Subaperture Processing,
Phased Array Radar,
SAR Processing,
Multi-Channel SAR,
MTI,
AER-II,
PAMIR,
Subaperture Processing,
Phased Array Radar,
Tomography,
SAR Tomography.
Abstract: SAR systems equipped with a phased array antenna and several receiver channels offer additional flexibility and extended target signatures. Besides of the electronic beam-steering permitting interesting operational modes, the partitioning into subarrays with parallel receiving channels opens the possibility to receive multichannel signals containing much more information about the scene than in the classical single channel case. In this paper, we start from a general signal model for wideband multi-channel data. This signal model serves as a basis for the development of algorithms for some special array configurations and applications. The approach is done from a signal theoretical point of view including statistical analysis. Most of the methods apply also to small groups of classical antennas, so the considerations are not limited to phased arrays. The airborne experimental multi-channel SAR systems AER and PAMIR serve as demonstrators for extended possibilities of imaging radars equipped with active phased arrays and parallel receiving channels. The presented examples have been achieved with these demonstrators. Comments: + Much und MTI, but topics like SAR tomography are covered as well. Anything that is multi-channel. @InProceedings{ender03:SARMTITomo, Title = {{SAR/MTI with Multi-Subaperture Phased Arrays}}, Author = {Joachim H. G. Ender}, Booktitle = {Proceedings of the Tyrrhenian International Workshop on Remote Sensing TIWRS}, Month = sep, Pages = {313-331}, Year = {2003}, Abstract = {SAR systems equipped with a phased array antenna and several receiver channels offer additional flexibility and extended target signatures. Besides of the electronic beam-steering permitting interesting operational modes, the partitioning into subarrays with parallel receiving channels opens the possibility to receive multichannel signals containing much more information about the scene than in the classical single channel case. In this paper, we start from a general signal model for wideband multi-channel data. This signal model serves as a basis for the development of algorithms for some special array configurations and applications. The approach is done from a signal theoretical point of view including statistical analysis. Most of the methods apply also to small groups of classical antennas, so the considerations are not limited to phased arrays. The airborne experimental multi-channel SAR systems AER and PAMIR serve as demonstrators for extended possibilities of imaging radars equipped with active phased arrays and parallel receiving channels. The presented examples have been achieved with these demonstrators.}, Comments = {+ Much und MTI, but topics like SAR tomography are covered as well. Anything that is multi-channel.}, Keyword = {SAR, Multi-Channel SAR, MTI, AER-II, PAMIR, Subaperture Processing, Phased Array Radar}, Keywords = {SAR Processing, Multi-Channel SAR, MTI, AER-II, PAMIR, Subaperture Processing, Phased Array Radar, Tomography, SAR Tomography}, Owner = {ofrey}, Pdf = {../../../docs/ender03.pdf} } -
Joachim H.G. Ender and Andreas R. Brenner.
PAMIR - a wideband phased array SAR/MTI system.
In IEE Proceedings - Radar, Sonar and Navigation,
number 3,
pages 165-172,
June 2003.
Keyword(s): SAR Processing,
PAMIR,
MTI,
GMTI,
Time-Domain Back-Projection,
Back-Projection,
Spotlight SAR,
FGAN,
X-Band,
InSAR 1.8 GHz,
ISAR,
IfSAR,
Phased Array Multifunctional Imaging Radar,
X-band radar,
airborne imaging radar,
electronically steerable phased array,
ground moving objects,
ground moving target indication,
ground-moving target indication,
inverse SAR,
long-range imaging capabilities,
multichannel capability,
operational modes,
receive channels,
reconfigurable phased array antenna,
reconnaissance tasks,
resolution,
signal bandwidth,
single-pass interferometric SAR,
space-time adaptive processing,
spaceborne imaging radar,
subapertures,
surveillance,
synthetic aperture radar,
wideband phased array SAR/MTI system,
wideband system design.
Abstract: Air- and spaceborne imaging radar systems in forthcoming surveillance and reconnaissance tasks have to meet increasingly severe demands. The next generation of top-level synthetic aperture radar (SAR) systems will comprise, among others, high resolution and long-range imaging capabilities, highly sensitive ground moving target indication and a multitude of sophisticated operational modes. The variety of tasks can be fulfilled only by the use of a reconfigurable phased array antenna together with a comprehensive wideband system design and a multichannel capability. At FGAN a new experimental X-band radar has been conceived, which will possess in its final upgrade an electronically steerable phased array consisting of 16 autonomous and reconfigurable subapertures, five independent receive channels, and a total signal bandwidth of about 1.8 GHz. The sensor is called PAMIR (Phased Array Multifunctional Imaging Radar). It is envisaged to demonstrate SAR imaging at a very high resolution and for a long range. The fine resolution will also be achieved with inverse SAR (ISAR) imaging of ground moving objects. Furthermore, the number of receive channels will allow ground-moving target indication (GMTI) by space?time adaptive processing and single-pass interferometric SAR (IfSAR) with a very high 3-D resolution. In its current stage of extension PAMIR is operable with one receive channel and a mechanically steerable antenna array. The system design and the intended capabilities of PAMIR are described. Ground-based and airborne experimental results concerning high-resolution SAR and ISAR imaging are also presented. @InProceedings{enderBrennerIEE2003:PAMIR, author = {Joachim H.G. Ender and Andreas R. Brenner}, booktitle = {IEE Proceedings - Radar, Sonar and Navigation}, title = {PAMIR - a wideband phased array SAR/MTI system}, year = {2003}, month = {June}, number = {3}, pages = {165-172}, abstract = {Air- and spaceborne imaging radar systems in forthcoming surveillance and reconnaissance tasks have to meet increasingly severe demands. The next generation of top-level synthetic aperture radar (SAR) systems will comprise, among others, high resolution and long-range imaging capabilities, highly sensitive ground moving target indication and a multitude of sophisticated operational modes. The variety of tasks can be fulfilled only by the use of a reconfigurable phased array antenna together with a comprehensive wideband system design and a multichannel capability. At FGAN a new experimental X-band radar has been conceived, which will possess in its final upgrade an electronically steerable phased array consisting of 16 autonomous and reconfigurable subapertures, five independent receive channels, and a total signal bandwidth of about 1.8 GHz. The sensor is called PAMIR (Phased Array Multifunctional Imaging Radar). It is envisaged to demonstrate SAR imaging at a very high resolution and for a long range. The fine resolution will also be achieved with inverse SAR (ISAR) imaging of ground moving objects. Furthermore, the number of receive channels will allow ground-moving target indication (GMTI) by space?time adaptive processing and single-pass interferometric SAR (IfSAR) with a very high 3-D resolution. In its current stage of extension PAMIR is operable with one receive channel and a mechanically steerable antenna array. The system design and the intended capabilities of PAMIR are described. Ground-based and airborne experimental results concerning high-resolution SAR and ISAR imaging are also presented.}, keywords = {SAR Processing, PAMIR, MTI, GMTI, Time-Domain Back-Projection, Back-Projection, Spotlight SAR, FGAN, X-Band, InSAR 1.8 GHz, ISAR, IfSAR, Phased Array Multifunctional Imaging Radar, X-band radar, airborne imaging radar, electronically steerable phased array, ground moving objects, ground moving target indication, ground-moving target indication, inverse SAR, long-range imaging capabilities, multichannel capability, operational modes, receive channels, reconfigurable phased array antenna, reconnaissance tasks, resolution, signal bandwidth, single-pass interferometric SAR, space-time adaptive processing, spaceborne imaging radar, subapertures, surveillance, synthetic aperture radar, wideband phased array SAR/MTI system, wideband system design}, owner = {ofrey}, pdf = {../../../docs/enderBrennerIEE2003.pdf}, url = {http://ieeexplore.ieee.org/iel5/2198/27458/01222377.pdf}, } -
Tuo Fu,
Meiguo Gao,
and Yuan He.
An improved scatter selection method for phase gradient autofocus algorithm in SAR/ISAR autofocus.
In Neural Networks and Signal Processing, 2003. Proceedings of the 2003 International Conference on,
volume 2,
pages 1054-1057,
December 2003.
Keyword(s): SAR Processing,
Autofocus,
Phase Gradient Autofocus.
@InProceedings{Fu2003, author = {Tuo Fu and Meiguo Gao and Yuan He}, booktitle = {Neural Networks and Signal Processing, 2003. Proceedings of the 2003 International Conference on}, title = {An improved scatter selection method for phase gradient autofocus algorithm in {SAR/ISAR} autofocus}, year = {2003}, month = dec, pages = {1054--1057}, volume = {2}, doi = {10.1109/ICNNSP.2003.1281050}, keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus}, owner = {ofrey}, } -
C. Henry,
J. Souyris,
and P. Marthon.
Target detection and analysis based on spectral analysis of a SAR image: a simulation approach.
In Proc. IEEE Int. Geosci. Remote Sens. Symp.,
volume 3,
pages 2005-2007,
July 2003.
Keyword(s): SAR Processing,
Interferometry,
SAR Interferometry,
Persistent Scatterer Interferometry,
PSI,
Interferometric Point Target Analysis,
IPTA,
Analytical models,
Azimuth,
Image analysis,
Layout,
Object detection,
Radar imaging,
Radiometry,
Speckle,
Spectral analysis,
Synthetic aperture radar.
Abstract: In a previous study, the joint use of Synthetic Aperture Radar (SAR) image magnitude and phase has been assessed in the context of target detection. The two-looks Internal Hermitian Product (2L-IHP), based on a correlation between sub-looks of a single look complex (SLC) radar image, was introduced. It has been applied on an airborne radar image including deterministic targets deployed in a natural environment. The 2L-IHP was shown to increase the target environment contrast. @InProceedings{henrySouyrisMarthonIGARSS2003TargetDetectionSpectralAnalysis, author = {C. Henry and J. Souyris and P. Marthon}, title = {Target detection and analysis based on spectral analysis of a {SAR} image: a simulation approach}, booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.}, year = {2003}, volume = {3}, pages = {2005-2007}, month = jul, abstract = {In a previous study, the joint use of Synthetic Aperture Radar (SAR) image magnitude and phase has been assessed in the context of target detection. The two-looks Internal Hermitian Product (2L-IHP), based on a correlation between sub-looks of a single look complex (SLC) radar image, was introduced. It has been applied on an airborne radar image including deterministic targets deployed in a natural environment. The 2L-IHP was shown to increase the target environment contrast.}, doi = {10.1109/IGARSS.2003.1294321}, file = {:henrySouyrisMarthonIGARSS2003TargetDetectionSpectralAnalysis.pdf:PDF}, keywords = {SAR Processing, Interferometry, SAR Interferometry, Persistent Scatterer Interferometry, PSI, Interferometric Point Target Analysis, IPTA, Analytical models;Azimuth;Image analysis;Layout;Object detection;Radar imaging;Radiometry;Speckle;Spectral analysis;Synthetic aperture radar}, owner = {ofrey}, } -
A. Jakobsson,
F. Gini,
and F. Lombardini.
Layover solution in multibaseline INSAR using robust beamforming.
In Signal Processing and Information Technology, 2003. ISSPIT 2003. Proceedings of the 3rd IEEE International Symposium on,
pages 328-331,
December 2003.
@InProceedings{Jakobsson2003, Title = {Layover solution in multibaseline INSAR using robust beamforming}, Author = {Jakobsson, A. and Gini, F. and Lombardini, F.}, Booktitle = {Signal Processing and Information Technology, 2003. ISSPIT 2003. Proceedings of the 3rd IEEE International Symposium on}, Doi = {10.1109/ISSPIT.2003.1341125}, Month = dec, Pages = {328--331}, Year = {2003}, Owner = {ofrey} } -
A. Jakobsson,
F. Lombardini,
and F. Gini.
Weighted subspace fitting of interferometric phases for multibaseline SAR interferometry.
In Signal Processing and Its Applications, 2003. Proceedings. Seventh International Symposium on,
volume 1,
pages 321-324,
July 2003.
@InProceedings{Jakobsson2003a, Title = {Weighted subspace fitting of interferometric phases for multibaseline SAR interferometry}, Author = {Jakobsson, A. and Lombardini, F. and Gini, F.}, Booktitle = {Signal Processing and Its Applications, 2003. Proceedings. Seventh International Symposium on}, Doi = {10.1109/ISSPA.2003.1224705}, Month = jul, Pages = {321--324}, Volume = {1}, Year = {2003}, Owner = {ofrey} } -
J.S. Lee,
D.L. Schuler,
T.L. Ainsworth,
and W.-M. Boerner.
Polarization orientation estimation and applications: a review.
In IEEE International Geoscience and Remote Sensing Symposium, 2003. IGARSS '03.,
volume 1,
pages 428-430,
July 2003.
Keyword(s): SAR Processsing,
calibration,
covariance matrices,
data acquisition,
radar polarimetry,
remote sensing by radar,
spaceborne radar,
synthetic aperture radar,
terrain mapping DEM generation,
AIRSAR,
L-band,
polarimetric SAR images,
P-band,
SIR-C,
circular polarization covariance matrix,
estimation algorithms,
ocean surface feature characterization,
polarimetric SAR data compensation,
polarimetric calibration,
polarization orientation angle shifts,
polarization orientation estimation,
radar frequency,
scattering media,
terrain slopes,
Airborne SAR.
Abstract: We review estimation algorithms and applications of polarization orientation angle shifts induced by terrain slopes. We develop a unified analysis of estimation algorithms based on circular polarization covariance matrix. The effect of radar frequency, scattering media, and polarimetric calibration will also be discussed. Applications to DEM generation, polarimetric SAR data compensation and ocean surface feature characterization will be mentioned. SIR-C, and JPL AIRSAR L-band and P-band polarimetric SAR images are used for demonstration. @InProceedings{leeSchulerAinsworthBoerner2003:PolSAR, author = {Lee, J.S. and Schuler, D.L. and Ainsworth, T.L. and Boerner, W.-M.}, booktitle = {IEEE International Geoscience and Remote Sensing Symposium, 2003. IGARSS '03.}, title = {Polarization orientation estimation and applications: a review}, year = {2003}, month = {jul}, pages = {428--430}, volume = {1}, abstract = {We review estimation algorithms and applications of polarization orientation angle shifts induced by terrain slopes. We develop a unified analysis of estimation algorithms based on circular polarization covariance matrix. The effect of radar frequency, scattering media, and polarimetric calibration will also be discussed. Applications to DEM generation, polarimetric SAR data compensation and ocean surface feature characterization will be mentioned. SIR-C, and JPL AIRSAR L-band and P-band polarimetric SAR images are used for demonstration.}, keywords = {SAR Processsing, calibration, covariance matrices, data acquisition, radar polarimetry, remote sensing by radar, spaceborne radar, synthetic aperture radar, terrain mapping DEM generation, AIRSAR, L-band, polarimetric SAR images, P-band, SIR-C, circular polarization covariance matrix, estimation algorithms, ocean surface feature characterization, polarimetric SAR data compensation, polarimetric calibration, polarization orientation angle shifts, polarization orientation estimation, radar frequency, scattering media, terrain slopes, Airborne SAR}, owner = {ofrey}, pdf = {../../../docs/leeSchulerAinsworthBoerner2003.pdf}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1293798&isnumber=28601}, } -
F. Lombardini.
Differential tomography: a new framework for SAR interferometry.
In Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International,
volume 2,
pages 1206-1208,
July 2003.
@InProceedings{Lombardini2003, Title = {Differential tomography: a new framework for SAR interferometry}, Author = {Lombardini, F.}, Booktitle = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, Doi = {10.1109/IGARSS.2003.1294059}, Month = jul, Pages = {1206--1208}, Volume = {2}, Year = {2003}, Owner = {ofrey}, Timestamp = {2009.07.01} } -
F. Lombardini and F. Gini.
Multiple reflectivities estimation for multibaseline InSAR imaging of layover extended sources.
In Radar Conference, 2003. Proceedings of the International,
pages 257-263,
September 2003.
@InProceedings{Lombardini2003b, Title = {Multiple reflectivities estimation for multibaseline InSAR imaging of layover extended sources}, Author = {Lombardini, F. and Gini, F.}, Booktitle = {Radar Conference, 2003. Proceedings of the International}, Doi = {10.1109/RADAR.2003.1278749}, Month = sep, Pages = {257--263}, Year = {2003}, Owner = {ofrey} } -
Fabrizio Lombardini and Andreas Reigber.
Adaptive spectral estimation for multibaseline SAR tomography with airborne L-band data.
In IEEE International Geoscience and Remote Sensing Symposium, IGARSS '03.,
volume 3,
pages 2014-2016,
2003.
Keyword(s): SAR Processing,
Tomography,
SAR Tomography,
Capon spectral estimator,
adaptive Capon spectral estimator,
spectral estimation,
multibaseline 3D SAR focusing,
multi-baseline SAR,
InSAR,
Multibaseline InSAR,
Forestry.
Abstract: In the recent years there has been growing interest in exploiting multibaseline (MB) SAR interferometry in a tomographic framework, to produce full 3D imaging e.g. of forest layers. However, Fourier-based MB SAR tomography is generally affected by unsatisfactory imaging quality due to a typically low number of baselines and their irregular distribution. In this work, we apply the more modern adaptive Capon spectral estimator to the vertical image reconstruction problem, using real airborne MB data. A first demonstration of possible imaging enhancement in real-world conditions is given. @InProceedings{lombardiniReigber03:TomoCapon, author = {Lombardini, Fabrizio and Reigber, Andreas}, booktitle = {IEEE International Geoscience and Remote Sensing Symposium, IGARSS '03.}, title = {{Adaptive spectral estimation for multibaseline SAR tomography with airborne L-band data}}, year = {2003}, pages = {2014--2016}, volume = {3}, abstract = {In the recent years there has been growing interest in exploiting multibaseline (MB) SAR interferometry in a tomographic framework, to produce full 3D imaging e.g. of forest layers. However, Fourier-based MB SAR tomography is generally affected by unsatisfactory imaging quality due to a typically low number of baselines and their irregular distribution. In this work, we apply the more modern adaptive Capon spectral estimator to the vertical image reconstruction problem, using real airborne MB data. A first demonstration of possible imaging enhancement in real-world conditions is given.}, keywords = {SAR Processing, Tomography, SAR Tomography, Capon spectral estimator, adaptive Capon spectral estimator, spectral estimation, multibaseline 3D SAR focusing, multi-baseline SAR, InSAR, Multibaseline InSAR, Forestry}, owner = {ofrey}, pdf = {../../../docs/lombardiniReigber03.pdf}, url = {http://ieeexplore.ieee.org/iel5/9010/28603/01294324.pdf}, } -
A. Löw and W. Mauser.
Generation of geometrically and radiometrically terrain corrected ScanSAR images.
In IEEE International Geoscience and Remote Sensing Symposium, 2003. IGARSS '03,
volume 6,
pages 3995-3997,
2003.
Keyword(s): SAR Processing,
SAR Geocoding,
Radiometric Calibration,
Calibration,
Radiometric Correction,
backscatter,
microwave imaging,
radiometry,
synthetic aperture radar,
terrain mapping,
topography (Earth),
ENVISAT,
ASAR,
RADARSAT,
biophysical parameters,
geometrically terrain corrected ScanSAR images,
ScanSAR,
geophysical parameters,
microwave imagery,
quantitative image analysis,
radiometrically terrain corrected ScanSAR images,
surface topography,
synthetic aperture imagery.
Abstract: Inclined surface topography diminishes the geometric and radiometric quality of synthetic aperture imagery. The correction of these effects becomes indispensable when quantitative image analysis is performed with respect to the derivation of geo- and biophysical parameters. Due to their spatial extent and frequent availability, ScanSAR image products extend the operative range of microwave imagery and have a high potential for numerous operational applications over larger areas. The study presents a procedure for a pre-operational terrain correction of ScanSAR imagery as acquired by RADARSAT and ENVISAT ASAR. @InProceedings{loewMauser03:RadiometricCalibration, author = {L{\"o}w, A. and Mauser, W.}, booktitle = {IEEE International Geoscience and Remote Sensing Symposium, 2003. IGARSS '03}, title = {Generation of geometrically and radiometrically terrain corrected ScanSAR images}, year = {2003}, pages = {3995-3997}, volume = {6}, abstract = {Inclined surface topography diminishes the geometric and radiometric quality of synthetic aperture imagery. The correction of these effects becomes indispensable when quantitative image analysis is performed with respect to the derivation of geo- and biophysical parameters. Due to their spatial extent and frequent availability, ScanSAR image products extend the operative range of microwave imagery and have a high potential for numerous operational applications over larger areas. The study presents a procedure for a pre-operational terrain correction of ScanSAR imagery as acquired by RADARSAT and ENVISAT ASAR.}, keywords = {SAR Processing, SAR Geocoding, Radiometric Calibration, Calibration, Radiometric Correction, backscatter, microwave imaging, radiometry, synthetic aperture radar, terrain mapping, topography (Earth), ENVISAT, ASAR, RADARSAT, biophysical parameters, geometrically terrain corrected ScanSAR images, ScanSAR, geophysical parameters, microwave imagery, quantitative image analysis, radiometrically terrain corrected ScanSAR images, surface topography, synthetic aperture imagery}, owner = {ofrey}, pdf = {../../../docs/loewMauser03.pdf}, url = {http://ieeexplore.ieee.org/iel5/9010/28606/01295340.pdf}, } -
P. Prats,
J. J. Mallorqui,
and A. Broquetas.
Calibration of interferometric airborne SAR images using a multisquint processing approach.
In Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International,
volume 7,
pages 4353-4355,
July 2003.
Keyword(s): SAR Processing,
Motion Compensation,
ESAR,
L-Band,
X-Band,
Airborne SAR,
Squinted SAR,
Interferometry,
azimuth phase undulations,
calibration,
image pairs,
interferometric airborne synthetic aperture radar systems,
InSAR,
multisquint processing,
phase error correction,
phase error detection,
single-pass interferometrie data.
@InProceedings{PratsMallorquiBroquetas2003a:MoComp, author = {Prats, P. and Mallorqui, J. J. and Broquetas, A.}, booktitle = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, title = {Calibration of interferometric airborne SAR images using a multisquint processing approach}, year = {2003}, month = jul, pages = {4353--4355}, volume = {7}, keywords = {SAR Processing, Motion Compensation, ESAR, L-Band, X-Band, Airborne SAR, Squinted SAR, Interferometry, azimuth phase undulations, calibration, image pairs, interferometric airborne synthetic aperture radar systems, InSAR, multisquint processing, phase error correction, phase error detection, single-pass interferometrie data}, owner = {ofrey}, pdf = {../../../docs/PratsMallorquiBroquetas2003a.pdf}, url = {http://ieeexplore.ieee.org/iel5/9010/28607/01295513.pdf}, } -
A. Reigber,
A. Potsis,
E. Alivizatos,
N. Uzunoglu,
and A. Moreira.
Wavenumber domain SAR focusing with integrated motion compensation.
In Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International,
volume 3,
pages 1465-1467,
2003.
Keyword(s): SAR Processing,
omega-k,
Range Migration Algorithm,
Wavenumber Domain Algorithm,
Extended omega-k,
Extended Wavenumber Domain Algorithm,
Motion Compensation,
Squinted SAR,
Airborne SAR.
Abstract: In this paper a new SAR data processing algorithm denoted with Extended Omega-K (EOK) is analytically presented and formulated. EOK algorithm combines the advantages of the high accurate focusing of the wavenumber domain algorithms with high precision motion compensation. The new EOK algorithm integrates a two-step range adaptive motion compensation correction in the general formulation of the wavenumber domain algorithm, leading to a new SAR processing scheme, which is much more robust concerning long synthetic apertures and squint angle than for example the chirp-scaling method. Additionally it offers the possibility of processing wideband low-frequency airborne SAR data up to near-wavelength resolution. The performance and the accuracy of the new EOK SAR data processing algorithm is demonstrated using simulated data. @InProceedings{reigberPotsisAlivizatosUzunogluMoreira03:ExtendedOmegaK, Title = {Wavenumber domain SAR focusing with integrated motion compensation}, Author = {Reigber, A. and Potsis, A. and Alivizatos, E. and Uzunoglu, N. and Moreira, A.}, Booktitle = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, Pages = {1465--1467}, Url = {http://ieeexplore.ieee.org/iel5/9010/28603/01294145.pdf}, Volume = {3}, Year = {2003}, Abstract = {In this paper a new SAR data processing algorithm denoted with Extended Omega-K (EOK) is analytically presented and formulated. EOK algorithm combines the advantages of the high accurate focusing of the wavenumber domain algorithms with high precision motion compensation. The new EOK algorithm integrates a two-step range adaptive motion compensation correction in the general formulation of the wavenumber domain algorithm, leading to a new SAR processing scheme, which is much more robust concerning long synthetic apertures and squint angle than for example the chirp-scaling method. Additionally it offers the possibility of processing wideband low-frequency airborne SAR data up to near-wavelength resolution. The performance and the accuracy of the new EOK SAR data processing algorithm is demonstrated using simulated data.}, Keywords = {SAR Processing, omega-k, Range Migration Algorithm, Wavenumber Domain Algorithm, Extended omega-k, Extended Wavenumber Domain Algorithm, Motion Compensation, Squinted SAR, Airborne SAR}, Owner = {ofrey}, Pdf = {../../../docs/reigberPotsisAlivizatosUzunogluMoreira03.pdf} } -
A. Reigber,
P. Prats,
R. Scheiber,
and J. J. Mallorqui.
Options for high-precision motion compensation for airborne differential SAR interferometry.
In Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International,
volume 7,
pages 4356-4358,
July 2003.
Keyword(s): SAR Processing,
D-InSAR,
InSAR,
ESAR,
Airborne SAR,
L-Band,
differential interferometry,
Interferometry,
Motion Compensation,
RME,
Residual Motion Errors,
Spectral Diversity,
Multi-Squint Processing,
Digital Elevation Model,
DEM.
@InProceedings{ReigberPratsScheiberMallorqui2003:MoComp, Title = {Options for high-precision motion compensation for airborne differential SAR interferometry}, Author = {Reigber, A. and Prats, P. and Scheiber, R. and Mallorqui, J. J.}, Booktitle = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, Month = jul, Pages = {4356--4358}, Url = {http://ieeexplore.ieee.org/iel5/9010/28607/01295514.pdf}, Volume = {7}, Year = {2003}, Keywords = {SAR Processing, D-InSAR, InSAR, ESAR, Airborne SAR, L-Band, differential interferometry, Interferometry, Motion Compensation, RME, Residual Motion Errors, Spectral Diversity, Multi-Squint Processing, Digital Elevation Model, DEM}, Owner = {ofrey}, Pdf = {../../../docs/ReigberPratsScheiberMallorqui2003.pdf} } -
M. Rombach and João Moreira.
Description and applications of the multipolarized dual band OrbiSAR-1 InSAR sensor.
In Radar Conference, 2003. Proceedings of the International,
volume 5,
pages 245-250,
2003.
Keyword(s): electromagnetic wave reflection,
electromagnetic wave scattering,
radar polarimetry,
remote sensing by radar,
Spaceborne SAR,
synthetic aperture radar,
terrain mapping,
topography (Earth),
vegetation mapping,
OrbiSAR-1 InSAR sensor,
area mapping,
bald earth height information,
biomass,
canopy top foliage scattering,
digital elevation,
forest-classification,
ground elevation,
interferometric SAR,
multipolarized dual band InSAR sensor,
permanent cloud covered tropical areas,
soil reflection,
surface elevation,
topographic maps,
trunk reflection,
vegetation density,
vegetation height,
vegetation/microwave interaction.
Abstract: In the last decade, interferometric SAR (InSAR) has reached a wide acceptance as being a suitable tool to generate high-precision digital elevation models. Especially in tropical areas, with nearly permanent cloud coverage, InSAR provides a cost-efficient means for mapping large areas in short time periods. However, the interaction of microwaves with vegetation is strongly dependant on their frequency, demanding a careful interpretation of the extracted information. Short waves like X-band are mainly scattered back from the top of the canopy, whereas P-band penetrates the foliage and gets reflected from trunk and soil, thus carrying the phase information (and therefore the height information as well) from bald earth. For the generation of topographic maps, generally the ground elevation rather than the surface elevation is required, whereas the surface and ground elevation together enable the estimation of additional physical parameters like vegetation height, density, or biomass. @InProceedings{RombachMoreira03:OrbiSAR, Title = {Description and applications of the multipolarized dual band OrbiSAR-1 InSAR sensor}, Author = {Rombach, M. and Jo{\~a}o Moreira}, Booktitle = {Radar Conference, 2003. Proceedings of the International}, Pages = {245--250}, Url = {http://ieeexplore.ieee.org/iel5/9000/28560/01278747.pdf}, Volume = {5}, Year = {2003}, Abstract = {In the last decade, interferometric SAR (InSAR) has reached a wide acceptance as being a suitable tool to generate high-precision digital elevation models. Especially in tropical areas, with nearly permanent cloud coverage, InSAR provides a cost-efficient means for mapping large areas in short time periods. However, the interaction of microwaves with vegetation is strongly dependant on their frequency, demanding a careful interpretation of the extracted information. Short waves like X-band are mainly scattered back from the top of the canopy, whereas P-band penetrates the foliage and gets reflected from trunk and soil, thus carrying the phase information (and therefore the height information as well) from bald earth. For the generation of topographic maps, generally the ground elevation rather than the surface elevation is required, whereas the surface and ground elevation together enable the estimation of additional physical parameters like vegetation height, density, or biomass.}, Keywords = {electromagnetic wave reflection, electromagnetic wave scattering, radar polarimetry, remote sensing by radar, Spaceborne SAR, synthetic aperture radar, terrain mapping, topography (Earth), vegetation mapping, OrbiSAR-1 InSAR sensor, area mapping, bald earth height information, biomass, canopy top foliage scattering, digital elevation, forest-classification, ground elevation, interferometric SAR, multipolarized dual band InSAR sensor, permanent cloud covered tropical areas, soil reflection, surface elevation, topographic maps, trunk reflection, vegetation density, vegetation height, vegetation/microwave interaction}, Owner = {ofrey}, Pdf = {../../../docs/RombachMoreira03.pdf} } -
R. Scheiber.
A three-step phase correction approach for airborne repeat-pass interferometric SAR data.
In Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International,
volume 2,
pages 1190-1192,
July 2003.
@InProceedings{Scheiber2003, Title = {A three-step phase correction approach for airborne repeat-pass interferometric SAR data}, Author = {Scheiber, R.}, Booktitle = {Geoscience and Remote Sensing Symposium, 2003. IGARSS '03. Proceedings. 2003 IEEE International}, Doi = {10.1109/IGARSS.2003.1294054}, Month = jul, Pages = {1190--1192}, Volume = {2}, Year = {2003}, Owner = {ofrey}, Timestamp = {2009.07.01} } -
David Small,
Jürgen Holzner,
Hannes Raggam,
Detlef Kosmann,
and Adrian Schubert.
Geometric performance of ENVISAT ASAR products.
In IGARSS '03, International Geoscience and Remote Sensing Symposium,
volume 2,
pages 1121-1123,
2003.
Keyword(s): SAR Processing,
SAR Geocoding,
Geocoding,
synthetic aperture radar,
terrain mapping,
topography (Earth),
ASAR geolocation accuracy,
ASAR images,
ASAR slant range products,
DEM,
ENVISAT,
ASAR,
ENVISAT ASAR products,
ESA,
alternating polarization,
corner reflectors,
derivative geocoded products,
ellipsoid-geocoded products,
estimation techniques,
geometric performance,
ground control points,
ground range precision,
ground range products,
ground range transformation,
map features,
medium resolution products,
multiple validation,
nominally geocoded GTC locations,
radar geometry image products,
radar image,
single look complex,
topographic maps,
transponders,
wide swath mode acquisitions,
zero-Doppler iteration.
Abstract: We describe validation measurements of the geometric accuracy of ASAR images, measured redundantly via independent methods. Our tests include image (IM), alternating polarization (AP), and wide swath (WS) mode acquisitions over a variety of test sites. ASAR's slant range products (IMS/APS) require a slightly different validation methodology than ground range precision (IMP, APP) and medium resolution products (IMM, APM, WSM). A third approach is required for ellipsoid-geocoded products (IMG, APG). The most highly accurate validation is possible with single look complex (SLC) data (IMS and APS products), as all other product types lose resolution during multilooking. For a library of ground control points (GCPs) including map features such as bridges or road intersections, as well as (where available) transponders and corner reflectors, we use surveyed or map-measured position information (together with the delay value in the case of transponders) to solve the zero-Doppler iteration and predict the position of the GCP as an azimuth and slant range coordinate in the radar image. In the case of ground range products (e.g. IMP, APP, IMM, APM, WSM) the predicted slant range value is additionally transformed by a slant to ground range transformation tro determine the predicted image coordinate. The GCP feature is then either measured by inspection of a detected image, or localized automatically within the neighborhood of the prediction. GCPs are measured within the radar geometry image products, derivative geocoded products, and topographic maps, providing their measured map, radar geometry, and nominally geocoded GTC locations. Radar image locations are compared to map reference values and statistics of differences are tabulated. We compare the accuracies of the estimates achievable using transponders and map GCPs. Based on the suite of products (and accompanying orbit information) available to us, we establish a methodology for estimating a preliminary sampling window start time bias. The multiple validation and estimation techniques used ensure robust determination of ASAR geolocation accuracy. @InProceedings{smallHolznerRaggamKosmannSchubert03:ASARGeometricPerformance, author = {David Small and J{\"u}rgen Holzner and Hannes Raggam and Detlef Kosmann and Adrian Schubert}, booktitle = {IGARSS '03, International Geoscience and Remote Sensing Symposium}, title = {{Geometric performance of ENVISAT ASAR products}}, year = {2003}, pages = {1121--1123}, volume = {2}, abstract = {We describe validation measurements of the geometric accuracy of ASAR images, measured redundantly via independent methods. Our tests include image (IM), alternating polarization (AP), and wide swath (WS) mode acquisitions over a variety of test sites. ASAR's slant range products (IMS/APS) require a slightly different validation methodology than ground range precision (IMP, APP) and medium resolution products (IMM, APM, WSM). A third approach is required for ellipsoid-geocoded products (IMG, APG). The most highly accurate validation is possible with single look complex (SLC) data (IMS and APS products), as all other product types lose resolution during multilooking. For a library of ground control points (GCPs) including map features such as bridges or road intersections, as well as (where available) transponders and corner reflectors, we use surveyed or map-measured position information (together with the delay value in the case of transponders) to solve the zero-Doppler iteration and predict the position of the GCP as an azimuth and slant range coordinate in the radar image. In the case of ground range products (e.g. IMP, APP, IMM, APM, WSM) the predicted slant range value is additionally transformed by a slant to ground range transformation tro determine the predicted image coordinate. The GCP feature is then either measured by inspection of a detected image, or localized automatically within the neighborhood of the prediction. GCPs are measured within the radar geometry image products, derivative geocoded products, and topographic maps, providing their measured map, radar geometry, and nominally geocoded GTC locations. Radar image locations are compared to map reference values and statistics of differences are tabulated. We compare the accuracies of the estimates achievable using transponders and map GCPs. Based on the suite of products (and accompanying orbit information) available to us, we establish a methodology for estimating a preliminary sampling window start time bias. The multiple validation and estimation techniques used ensure robust determination of ASAR geolocation accuracy.}, keywords = {SAR Processing, SAR Geocoding, Geocoding, synthetic aperture radar, terrain mapping, topography (Earth), ASAR geolocation accuracy, ASAR images, ASAR slant range products, DEM, ENVISAT, ASAR, ENVISAT ASAR products, ESA, alternating polarization, corner reflectors, derivative geocoded products, ellipsoid-geocoded products, estimation techniques, geometric performance, ground control points, ground range precision, ground range products, ground range transformation, map features, medium resolution products, multiple validation, nominally geocoded GTC locations, radar geometry image products, radar image, single look complex, topographic maps, transponders, wide swath mode acquisitions, zero-Doppler iteration}, owner = {ofrey}, pdf = {../../../docs/smallHolznerRaggamKosmannSchubert03.pdf}, url = {http://ieeexplore.ieee.org/iel5/9010/28602/01294031.pdf}, } -
Gordon C. Staples and Joost van der Sanden.
RADARSAT-2 Polarimetry Applications.
In Anais XI SBSR, Simposio Brasileiro de Sensoriamento Remoto 2003, INPE, Belo Horizonte, Brasil,
volume 1,
pages 2383-2389,
2003.
Keyword(s): Radarsat-2,
Polarimetry,
Applications.
Abstract: RADARSAT-2, planned for a mid 2004 launch, is an advanced polarimetric SAR satellite. Key features of RADARSAT-2 are high resolution (3 m), polarimetric modes, enhanced ground system providing rapid satellite tasking and near-real time data processing, improved image location accuracy, and on-board solid state recorders. The focus of this paper is on the RADARSAT-2 polarimetric applications including agriculture, cartography, disaster management, forestry, geology, hydrology, oceans, and sea ice. @InProceedings{staples:radsat2pol, Title = {{RADARSAT-2 Polarimetry Applications}}, Author = {Gordon C. Staples and Joost van der Sanden}, Booktitle = {Anais XI SBSR, Simposio Brasileiro de Sensoriamento Remoto 2003, INPE, Belo Horizonte, Brasil}, Pages = {2383-2389}, Url = {http://lagavulin.ltid.inpe.br:1905/col/ltid.inpe.br/sbsr/2003/03.27.11.57/doc/17_471.PDF}, Volume = {1}, Year = {2003}, Abstract = {RADARSAT-2, planned for a mid 2004 launch, is an advanced polarimetric SAR satellite. Key features of RADARSAT-2 are high resolution (3 m), polarimetric modes, enhanced ground system providing rapid satellite tasking and near-real time data processing, improved image location accuracy, and on-board solid state recorders. The focus of this paper is on the RADARSAT-2 polarimetric applications including agriculture, cartography, disaster management, forestry, geology, hydrology, oceans, and sea ice.}, Keywords = {Radarsat-2, Polarimetry, Applications}, Pdf = {../../../docs/staples03.pdf} } -
B. Subiza,
E. Gimeno-Nieves,
J.M. Lopez-Sanchez,
and J. Fortuny-Guasch.
An Approach to SAR Imaging by Means of Non-Uniform FFTs.
In IEEE International Geoscience and Remote Sensing Symposium, 2003. IGARSS '03.,
volume 6,
pages 4089-4091,
July 2003.
Keyword(s): SAR Processing,
Range Migration Algorithm,
RMA,
omega-k,
NUFFT,
Non-Uniform Fast Fourier Transform,
Fast Fourier Transform,
FFT,
geophysical techniques,
interpolation,
radar imaging,
synthetic aperture radar,
SAR imaging algorithm,
Stolt interpolation,
computation time,
computational efficiency,
numerical simulations,
seismic migration SAR processing.
Abstract: In this study, the potential use of the non-uniform FFT (NUFFT) in SAR imaging is analyzed. The main objective has been the improvement of the computational efficiency and image accuracy of seismic migration SAR processing. Different NUFFT methods have been implemented and tested in order to choose an adequate technique for the imaging problem. Our approach consists in substituting both the Stolt interpolation and the final range inverse FFT, in the omega-k algorithm, by a single NUFFT. Numerical simulations illustrate the performance of the new method and the influence of the selection of NUFFT parameters in the precision and computation time of the SAR imaging algorithm. @InProceedings{subizaGimenoNievesLopezSanchezFortunyGuasch2003:NUFFT, author = {Subiza, B. and Gimeno-Nieves, E. and Lopez-Sanchez, J.M. and Fortuny-Guasch, J.}, booktitle = {IEEE International Geoscience and Remote Sensing Symposium, 2003. IGARSS '03.}, title = {An Approach to SAR Imaging by Means of Non-Uniform FFTs}, year = {2003}, month = {jul}, pages = {4089--4091}, volume = {6}, abstract = {In this study, the potential use of the non-uniform FFT (NUFFT) in SAR imaging is analyzed. The main objective has been the improvement of the computational efficiency and image accuracy of seismic migration SAR processing. Different NUFFT methods have been implemented and tested in order to choose an adequate technique for the imaging problem. Our approach consists in substituting both the Stolt interpolation and the final range inverse FFT, in the omega-k algorithm, by a single NUFFT. Numerical simulations illustrate the performance of the new method and the influence of the selection of NUFFT parameters in the precision and computation time of the SAR imaging algorithm.}, doi = {10.1109/IGARSS.2003.1295371}, keywords = {SAR Processing, Range Migration Algorithm, RMA, omega-k, NUFFT, Non-Uniform Fast Fourier Transform, Fast Fourier Transform, FFT, geophysical techniques, interpolation, radar imaging, synthetic aperture radar, SAR imaging algorithm, Stolt interpolation, computation time, computational efficiency, numerical simulations, seismic migration SAR processing}, owner = {ofrey}, pdf = {../../../docs/subizaGimenoNievesLopezSanchezFortunyGuasch2003.pdf}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1295371&isnumber=28606}, } -
T.J. Sutton,
H.D. Griffiths,
S.A. Chapman,
R. Crook,
and M. Way.
Optimizing a three-stage autofocus system for synthetic aperture imaging using a UUV.
In OCEANS 2003. Proceedings,
volume 5,
pages 2433-2437,
September 2003.
@InProceedings{Sutton2003a, Title = {Optimizing a three-stage autofocus system for synthetic aperture imaging using a UUV}, Author = {Sutton, T.J. and Griffiths, H.D. and Chapman, S.A. and Crook, R. and Way, M.}, Booktitle = {OCEANS 2003. Proceedings}, Month = sep, Pages = {2433--2437}, Volume = {5}, Year = {2003}, Owner = {ofrey}, Timestamp = {2007.06.13} } -
T.J. Sutton,
H.D. Griffiths,
A.P. Hetet,
Y. Perrot,
and S.A. Chapman.
Experimental validation of autofocus algorithms for high-resolution imaging of the seabed using synthetic aperture sonar.
In Radar, Sonar and Navigation, IEE Proceedings -,
volume 150,
pages 78-83,
April 2003.
@InProceedings{Sutton2003, Title = {Experimental validation of autofocus algorithms for high-resolution imaging of the seabed using synthetic aperture sonar}, Author = {Sutton, T.J. and Griffiths, H.D. and Hetet, A.P. and Perrot, Y. and Chapman, S.A.}, Booktitle = {Radar, Sonar and Navigation, IEE Proceedings -}, Doi = {10.1049/ip-rsn:20030213}, Month = {April}, Number = {2}, Pages = {78--83}, Volume = {150}, Year = {2003}, Owner = {ofrey}, Timestamp = {2007.06.13} } -
L. R. Varshney and D. Thomas.
Sidelobe reduction for matched filter range processing.
In Proc. IEEE Radar Conf.,
pages 446 - 451,
2003.
Keyword(s): SAR Processing,
Apodization,
Spatially Variant Apodization,
Dual Apodization,
leakage energy minimization,
linear frequency modulation,
matched filtering,
nonlinear frequency modulation,
pulse compression ratio,
range sidelobes,
sidelobe control,
sidelobe reduction,
chirp modulation,
frequency modulation,
matched filters,
minimisation,
nonlinear filters,
radar detection,
radar interference,
radar signal processing.
Abstract: Linear frequency modulation (LFM) matched filtering results in range sidelobes. These sidelobes are often objectionable because they may mask small targets or may be mistaken for targets themselves. Various methods of sidelobe control are investigated and their performance is measured. The methods of sidelobe reduction include dual apodization, spatially variant apodization, and leakage energy minimization. Nonlinear frequency modulation (NLFM) matched filtering is also investigated. A simulation was run to compare LFM with sidelobe control and NLFM, all using moderately low pulse compression ratios. Results suggest that generally, NLFM matched filtering has better detection and estimation characteristics than LFM with sidelobe control. @InProceedings{varshneyThomas2003:Apodization, author = {Varshney, L. R. and Thomas, D.}, booktitle = {Proc. IEEE Radar Conf.}, title = {Sidelobe reduction for matched filter range processing}, year = {2003}, pages = {446 - 451}, abstract = {Linear frequency modulation (LFM) matched filtering results in range sidelobes. These sidelobes are often objectionable because they may mask small targets or may be mistaken for targets themselves. Various methods of sidelobe control are investigated and their performance is measured. The methods of sidelobe reduction include dual apodization, spatially variant apodization, and leakage energy minimization. Nonlinear frequency modulation (NLFM) matched filtering is also investigated. A simulation was run to compare LFM with sidelobe control and NLFM, all using moderately low pulse compression ratios. Results suggest that generally, NLFM matched filtering has better detection and estimation characteristics than LFM with sidelobe control.}, doi = {10.1109/NRC.2003.1203439}, issn = {1097-5659}, keywords = {SAR Processing, Apodization, Spatially Variant Apodization, Dual Apodization, leakage energy minimization, linear frequency modulation, matched filtering, nonlinear frequency modulation, pulse compression ratio, range sidelobes, sidelobe control, sidelobe reduction, chirp modulation, frequency modulation, matched filters, minimisation, nonlinear filters, radar detection, radar interference, radar signal processing}, } -
Charles L. Werner,
Urs Wegmuller,
Tazio Strozzi,
and Andreas Wiesmann.
Interferometric point target analysis for deformation mapping.
In Proc. IEEE Int. Geosci. Remote Sens. Symp.,
volume 7,
pages 4362-4364,
2003.
Keyword(s): SAR Processing,
Interferometry,
SAR Interferometry,
Persistent Scatterer Interferometry,
PSI,
Interferometric Point Target Analysis,
IPTA,
synthetic aperture radar,
terrain mapping,
ERS-1 data,
ERS-2 data,
atmospheric path delays,
deformation mapping,
interferometric point target analysis,
surface deformation,
Atmospheric modeling,
Decorrelation,
Delay,
History,
Ice,
Interferometry,
Land surface,
Phase noise,
Remote sensing,
Volcanic activity.
Abstract: Interferometric Point Target Analysis (IPTA) is a method to exploit the temporal and spatial characteristics of interferometric signatures collected from point targets to accurately map surface deformation histories, terrain heights, and relative atmospheric path delays. In this contribution the IPTA concept is introduced, including the point selection criteria, the phase model and the iterative improvement of the model parameters. Intermediate and final results of an IPTA example using a stack of ERS-1 and ERS-2 data, confirm the validity of the concept and indicate a high accuracy of the resulting products. @InProceedings{wernerWegmullerStrozziWiesmann2003, author = {Werner, Charles L. and Wegmuller, Urs and Strozzi, Tazio and Wiesmann, Andreas}, title = {Interferometric point target analysis for deformation mapping}, booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.}, year = {2003}, volume = {7}, pages = {4362-4364}, abstract = {Interferometric Point Target Analysis (IPTA) is a method to exploit the temporal and spatial characteristics of interferometric signatures collected from point targets to accurately map surface deformation histories, terrain heights, and relative atmospheric path delays. In this contribution the IPTA concept is introduced, including the point selection criteria, the phase model and the iterative improvement of the model parameters. Intermediate and final results of an IPTA example using a stack of ERS-1 and ERS-2 data, confirm the validity of the concept and indicate a high accuracy of the resulting products.}, doi = {10.1109/IGARSS.2003.1295516}, file = {:wernerWegmullerStrozziWiesmann2003.pdf:PDF}, keywords = {SAR Processing, Interferometry, SAR Interferometry, Persistent Scatterer Interferometry, PSI, Interferometric Point Target Analysis, IPTA, synthetic aperture radar;terrain mapping;ERS-1 data;ERS-2 data;atmospheric path delays;deformation mapping;interferometric point target analysis;surface deformation;Atmospheric modeling;Decorrelation;Delay;History;Ice;Interferometry;Land surface;Phase noise;Remote sensing;Volcanic activity}, pdf = {../../../docs/wernerWegmullerStrozziWiesmann2003.pdf}, } -
Charles Werner,
Urs Wegmuller,
Andreas Wiesmann,
and Tazio Strozzi.
Interferometric point target analysis with JERS-1 L-band SAR data.
In Proc. IEEE Int. Geosci. Remote Sens. Symp.,
volume 7,
pages 4359-4361,
July 2003.
IEEE.
Keyword(s): SAR Processing,
Interferometry,
SAR Interferometry,
Persistent Scatterer Interferometry,
PSI,
Interferometric Point Target Analysis,
IPTA,
L-band,
Atmospheric modeling,
Deformable models,
Phase estimation,
Atmosphere,
Testing,
Surface topography,
Azimuth,
Remote sensing,
Sensor phenomena and characterization,
topography,
synthetic aperture radar,
spaceborne radar,
remote sensing by radar,
radiowave interferometry,
geophysical techniques,
subsidence,
JERS-1 L-band SAR data,
long-term coherence,
surface deformation,
Koga,
Japan.
Abstract: Interferometric Point Target Analysis (IPTA) is a method that exploits the temporal and spatial characteristics of interferometric signatures collected from point targets that exhibit long-term coherence to map surface deformation. This paper demonstrates the viability of this technique for L-band data collected by the JERS-1 sensor during the time period 1992-1998. A data set covering Koga, Japan is used for demonstration and indicates regions of substantial subsidence. @InProceedings{wernerWegmullerWiesmannStrozziIGARSS2003PSIIPTAJERS, author = {Werner, Charles and Wegmuller, Urs and Wiesmann, Andreas and Strozzi, Tazio}, booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.}, title = {Interferometric point target analysis with {JERS-1} {L-}band {SAR} data}, year = {2003}, month = jul, organization = {IEEE}, pages = {4359-4361}, volume = {7}, abstract = {Interferometric Point Target Analysis (IPTA) is a method that exploits the temporal and spatial characteristics of interferometric signatures collected from point targets that exhibit long-term coherence to map surface deformation. This paper demonstrates the viability of this technique for L-band data collected by the JERS-1 sensor during the time period 1992-1998. A data set covering Koga, Japan is used for demonstration and indicates regions of substantial subsidence.}, doi = {10.1109/IGARSS.2003.1295515}, file = {:wernerWegmullerWiesmannStrozziIGARSS2003PSIIPTAJERS.pdf:PDF}, keywords = {SAR Processing, Interferometry, SAR Interferometry, Persistent Scatterer Interferometry, PSI, Interferometric Point Target Analysis, IPTA, L-band, Atmospheric modeling, Deformable models, Phase estimation, Atmosphere, Testing, Surface topography, Azimuth, Remote sensing, Sensor phenomena and characterization, topography, synthetic aperture radar, spaceborne radar, remote sensing by radar, radiowave interferometry, geophysical techniques, subsidence, JERS-1 L-band SAR data, long-term coherence, surface deformation, Koga, Japan}, owner = {ofrey}, } -
David A. Yocky and Charles V. Jakowatz.
Automated wide-angle SAR stereo height extraction in rugged terrain using shift-scaling correlation.
In Andrew G. Tescher, editor,
,
volume 5203,
pages 10-20,
2003.
SPIE.
Keyword(s): SAR Processing,
Stereo SAR,
Rugged Terrain,
Polar Format Algorithm,
PFA,
Spotlight SAR,
Spotlight-mode data.
@Conference{yockyJakowatzStereoHeightExatraction, author = {David A. Yocky and Charles V. Jakowatz, Jr.}, title = {Automated wide-angle {SAR} stereo height extraction in rugged terrain using shift-scaling correlation}, year = {2003}, editor = {Andrew G. Tescher}, volume = {5203}, number = {1}, pages = {10-20}, publisher = {SPIE}, doi = {10.1117/12.502706}, file = {:yockyJakowatzStereoHeightExatraction.pdf:PDF}, journal = {Applications of Digital Image Processing XXVI}, keywords = {SAR Processing, Stereo SAR, Rugged Terrain, Polar Format Algorithm, PFA, Spotlight SAR, Spotlight-mode data}, location = {San Diego, CA, USA}, owner = {ofrey}, pdf = {../../../docs/yockyJakowatzStereoHeightExatraction.pdf}, url = {http://link.aip.org/link/?PSI/5203/10/1}, }
Internal reports
-
Michiel Otten and Henno Boomkamp.
Estimation of the Absolute Orbit Accuracy of Envisat.
Technical report,
European Space Operations Centre (ESOC),
Robert-Bosch Strasse 5, D-64283 Darmstadt,
2003.
Keyword(s): ENVISAT,
DORIS,
Precise Orbit,
Orbit,
Orbit Accuracy,
Accuracy,
ASAR.
Abstract: This paper presents the results of the orbit comparison campaign conducted at the European Space Operations Centre (ESOC) in May 2003. The goal of the comparison is to better quantify the absolute orbit accuracy of ENVISAT. For this comparison cycle 12 of ENVISAT was selected which corresponds to a period of 35 days starting at 10.12.2002 and ending at 13.01.2003. Two days, 18 and 19 December, were excluded within this period from the comparison. These days were selected because of the large inclination manoeuvre on 18 December and the resulting loss of DORIS and SLR tracking data for nearly a day. Six different centers contributed their POD solution to the comparison. The CNES POD solution used in this comparison is the same solution as the one that is found on the ENVISAT altimeter GDR. The JPL-DORIS solution only uses the DORIS tracking dataset and is based on the EGM- 96 gravity field where all the other centers use DORIS and SLR data and the GRIM5-C1 field. Three complementary analysis methods where applied to all contributions, namely pair-wise orbit comparison, SLR tracking data analysis and altimeter crossover analysis. @TechReport{ottenBoomkamp03:DorisAbsAccuracy, Title = {{Estimation of the Absolute Orbit Accuracy of Envisat}}, Author = {Michiel Otten and Henno Boomkamp}, Institution = {European Space Operations Centre (ESOC)}, Url = {http://nng.esoc.esa.de/envisat/results/campaign.pdf}, Year = {2003}, Abstract = {This paper presents the results of the orbit comparison campaign conducted at the European Space Operations Centre (ESOC) in May 2003. The goal of the comparison is to better quantify the absolute orbit accuracy of ENVISAT. For this comparison cycle 12 of ENVISAT was selected which corresponds to a period of 35 days starting at 10.12.2002 and ending at 13.01.2003. Two days, 18 and 19 December, were excluded within this period from the comparison. These days were selected because of the large inclination manoeuvre on 18 December and the resulting loss of DORIS and SLR tracking data for nearly a day. Six different centers contributed their POD solution to the comparison. The CNES POD solution used in this comparison is the same solution as the one that is found on the ENVISAT altimeter GDR. The JPL-DORIS solution only uses the DORIS tracking dataset and is based on the EGM- 96 gravity field where all the other centers use DORIS and SLR data and the GRIM5-C1 field. Three complementary analysis methods where applied to all contributions, namely pair-wise orbit comparison, SLR tracking data analysis and altimeter crossover analysis.}, Address = {Robert-Bosch Strasse 5, D-64283 Darmstadt}, Keywords = {ENVISAT, DORIS, Precise Orbit, Orbit, Orbit Accuracy, Accuracy, ASAR}, Owner = {ofrey}, Pdf = {../../../docs/ottenBoomkamp03.pdf} }
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Last modified: Fri Feb 24 14:22:26 2023
Author: Othmar Frey, Earth Observation and Remote Sensing, Institute of Environmental Engineering, Swiss Federal Institute of Technology - ETH Zurich .
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