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Publications of year 1997

Books and proceedings

  1. Akira Ishimaru. Wave Propagation and Scattering in Random Media. Wiley-IEEE Press, 1997. Keyword(s): Wave characteristics in aerosols and hydrometeors, Optical and acoustic scattering in sea water, Scattering from biological materials, Pulse scattering and beam wave propagation in such media, Optical diffusion in tissues and blood, Transport and radiative transfer theory, Kubelka-Munk flux theory and plane-parallel problem, Multiple scattering theory, Wave fluctuations in turbulence, Strong fluctuation theory, Rough surface scattering, Remote sensing and inversion techniques, Imaging through various media.
    Abstract: Electrical Engineering Wave Propagation and Scattering in Random Media A volume in the IEEE/OUP Series on Electromagnetic Wave Theory Donald G. Dudley, Series Editor This IEEE Classic Reissue presents a unified introduction to the fundamental theories and applications of wave propagation and scattering in random media. Now for the first time, the two volumes of Wave Propagation and Scattering in Random Media previously published by Academic Press in 1978 are combined into one comprehensive volume. This book presents a clear picture of how waves interact with the atmosphere, terrain, ocean, turbulence, aerosols, rain, snow, biological tissues, composite material, and other media. The theories presented will enable you to solve a variety of problems relating to clutter, interference, imaging, object detection, and communication theory for various media. This book is expressly designed for engineers and scientists who have an interest in optical, microwave, or acoustic wave propagation and scattering. Topics covered include: * Wave characteristics in aerosols and hydrometeors * Optical and acoustic scattering in sea water * Scattering from biological materials * Pulse scattering and beam wave propagation in such media * Optical diffusion in tissues and blood * Transport and radiative transfer theory * Kubelka--Munk flux theory and plane-parallel problem * Multiple scattering theory * Wave fluctuations in turbulence * Strong fluctuation theory * Rough surface scattering * Remote sensing and inversion techniques * Imaging through various media About the IEEE/OUP Series on Electromagnetic Wave Theory Formerly the IEEE Press Series on Electromagnetic Waves, this joint series between IEEE Press and Oxford University Press offers outstanding coverage of the field with new titles as well as reprintings and revisions of recognized classics that maintain long-term archival significance in electromagnetic waves and applications. Designed specifically for graduate students, practicing engineers, and researchers, this series provides affordable volumes that explore electromagnetic waves and applications beyond the undergraduate level. See page il of the front matter for a listing of books in this series. 

    @Book{bookIshimaru1997WavePropagationAndScatteringInRandomMedia,
author = {Ishimaru, Akira},
publisher = {Wiley-IEEE Press},
title = {Wave Propagation and Scattering in Random Media},
year = {1997},
isbn = {9780470547045},
abstract = {Electrical Engineering Wave Propagation and Scattering in Random Media A volume in the IEEE/OUP Series on Electromagnetic Wave Theory Donald G. Dudley, Series Editor This IEEE Classic Reissue presents a unified introduction to the fundamental theories and applications of wave propagation and scattering in random media. Now for the first time, the two volumes of Wave Propagation and Scattering in Random Media previously published by Academic Press in 1978 are combined into one comprehensive volume. This book presents a clear picture of how waves interact with the atmosphere, terrain, ocean, turbulence, aerosols, rain, snow, biological tissues, composite material, and other media. The theories presented will enable you to solve a variety of problems relating to clutter, interference, imaging, object detection, and communication theory for various media. This book is expressly designed for engineers and scientists who have an interest in optical, microwave, or acoustic wave propagation and scattering. Topics covered include: * Wave characteristics in aerosols and hydrometeors * Optical and acoustic scattering in sea water * Scattering from biological materials * Pulse scattering and beam wave propagation in such media * Optical diffusion in tissues and blood * Transport and radiative transfer theory * Kubelka--Munk flux theory and plane-parallel problem * Multiple scattering theory * Wave fluctuations in turbulence * Strong fluctuation theory * Rough surface scattering * Remote sensing and inversion techniques * Imaging through various media About the IEEE/OUP Series on Electromagnetic Wave Theory Formerly the IEEE Press Series on Electromagnetic Waves, this joint series between IEEE Press and Oxford University Press offers outstanding coverage of the field with new titles as well as reprintings and revisions of recognized classics that maintain long-term archival significance in electromagnetic waves and applications. Designed specifically for graduate students, practicing engineers, and researchers, this series provides affordable volumes that explore electromagnetic waves and applications beyond the undergraduate level. See page il of the front matter for a listing of books in this series.},
eprint = {https://ieeexplore.ieee.org/servlet/opac?bknumber=5270963},
file = {:bookIshimaru1997WavePropagationAndScatteringInRandomMedia.pdf:PDF},
keywords = {Wave characteristics in aerosols and hydrometeors, Optical and acoustic scattering in sea water, Scattering from biological materials, Pulse scattering and beam wave propagation in such media, Optical diffusion in tissues and blood, Transport and radiative transfer theory, Kubelka-Munk flux theory and plane-parallel problem, Multiple scattering theory, Wave fluctuations in turbulence, Strong fluctuation theory, Rough surface scattering, Remote sensing and inversion techniques, Imaging through various media},
owner = {ofrey},

}


Articles in journal or book chapters

  1. Shane R. Cloude and Eric Pottier. An entropy based classification scheme for land applications of polarimetric SAR. IEEE Trans. Geosci. Remote Sens., 35(1):68-78, January 1997. Keyword(s): SAR Processing, Polarimetric Decomposition, Cloude-Pottier Decomposition, Polarimetry, PolSAR, Entropy, Anisotropy, Alpha, H-A-alpha, S-matrix theory, geophysical signal processing, geophysical techniques, image classification, radar imaging, radar polarimetry, radar theory, remote sensing by radar, synthetic aperture radar, average target scattering matrix parameters, coherency matrix, eigenvalue analysis, entropy based classification, geophysical measurement technique, land surface, land use, parameterization, polarimetric SAR, polarimetric scattering problem, quantitative analysis, radar remote sensing, scattering entropy, terrain mapping, three-level Bernoulli statistical model, unsupervised classifier.
    Abstract: The authors outline a new scheme for parameterizing polarimetric scattering problems, which has application in the quantitative analysis of polarimetric SAR data. The method relies on an eigenvalue analysis of the coherency matrix and employs a three-level Bernoulli statistical model to generate estimates of the average target scattering matrix parameters from the data. The scattering entropy is a key parameter is determining the randomness in this model and is seen as a fundamental parameter in assessing the importance of polarimetry in remote sensing problems. The authors show application of the method to some important classical random media scattering problems and apply it to POLSAR data from the NASA/JPL AIRSAR data base 

    @Article{cloudePottier1997:EntropyAalpha,
author = {Cloude, Shane R. and Pottier, Eric},
journal = {IEEE Trans. Geosci. Remote Sens.},
title = {An entropy based classification scheme for land applications of polarimetric {SAR}},
year = {1997},
issn = {0196-2892},
month = jan,
number = {1},
pages = {68-78},
volume = {35},
abstract = {The authors outline a new scheme for parameterizing polarimetric scattering problems, which has application in the quantitative analysis of polarimetric SAR data. The method relies on an eigenvalue analysis of the coherency matrix and employs a three-level Bernoulli statistical model to generate estimates of the average target scattering matrix parameters from the data. The scattering entropy is a key parameter is determining the randomness in this model and is seen as a fundamental parameter in assessing the importance of polarimetry in remote sensing problems. The authors show application of the method to some important classical random media scattering problems and apply it to POLSAR data from the NASA/JPL AIRSAR data base},
doi = {10.1109/36.551935},
keywords = {SAR Processing, Polarimetric Decomposition, Cloude-Pottier Decomposition, Polarimetry, PolSAR, Entropy, Anisotropy, Alpha, H-A-alpha, S-matrix theory, geophysical signal processing, geophysical techniques, image classification, radar imaging, radar polarimetry, radar theory, remote sensing by radar, synthetic aperture radar, average target scattering matrix parameters, coherency matrix, eigenvalue analysis, entropy based classification, geophysical measurement technique, land surface, land use, parameterization, polarimetric SAR, polarimetric scattering problem, quantitative analysis, radar remote sensing, scattering entropy, terrain mapping, three-level Bernoulli statistical model, unsupervised classifier},
owner = {ofrey},
pdf = {../../../docs/cloudePottier1997.pdf},
url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=551935&isnumber=11971},

}


  2. G. Fornaro, G. Franceschetti, R. Lanari, D. Rossi, and M. Tesauro. Interferometric SAR phase unwrapping using the finite element method. IEE Proceedings - Radar, Sonar and Navigation, 144(5):266-274, October 1997. Keyword(s): IFSAR images, computations speedup, efficiency, experiments, finite element method, interferometric SAR phase unwrapping, least-squares solution, multigrid technique, noise robust method, phase unwrapping, precision, real ERS-I data, simulated patterns, time domain, two-dimensional algorithm, weighting functions, finite element analysis, least squares approximations, radar imaging, radiowave interferometry, synthetic aperture radar, time-domain analysis.
    Abstract: The authors present a new two-dimensional algorithm for interferometric synthetic aperture radar phase unwrapping based on the finite element method. The proposed technique allows an efficient least-squares solution carried out in the time domain. Weighting functions can be introduced without increasing the computational requirements. The possibility to speed up the computations via a multigrid technique is discussed. A noise-robust extension of the proposed technique is also investigated. The presented experiments on real ERS-I data, as well as on simulated patterns, demonstrate the precision and efficiency of the procedure 

    @Article{635858,
Title = {Interferometric {SAR} phase unwrapping using the finite element method},
Author = {Fornaro, G. and Franceschetti, G. and Lanari, R. and Rossi, D. and Tesauro, M.},
Doi = {10.1049/ip-rsn:19971259},
ISSN = {1350-2395},
Month = oct,
Number = {5},
Pages = {266-274},
Volume = {144},
Year = {1997},
Abstract = {The authors present a new two-dimensional algorithm for interferometric synthetic aperture radar phase unwrapping based on the finite element method. The proposed technique allows an efficient least-squares solution carried out in the time domain. Weighting functions can be introduced without increasing the computational requirements. The possibility to speed up the computations via a multigrid technique is discussed. A noise-robust extension of the proposed technique is also investigated. The presented experiments on real ERS-I data, as well as on simulated patterns, demonstrate the precision and efficiency of the procedure},
Journal = {IEE Proceedings - Radar, Sonar and Navigation},
Keywords = {IFSAR images;computations speedup;efficiency;experiments;finite element method;interferometric SAR phase unwrapping;least-squares solution;multigrid technique;noise robust method;phase unwrapping;precision;real ERS-I data;simulated patterns;time domain;two-dimensional algorithm;weighting functions;finite element analysis;least squares approximations;radar imaging;radiowave interferometry;synthetic aperture radar;time-domain analysis} 
}


  3. G. Fornaro, V. Pascazio, and G. Schirinzi. Synthetic aperture radar interferometry using one bit coded raw and reference signals. IEEE Transactions on Geoscience and Remote Sensing, 35(5):1245 -1253, September 1997. Keyword(s): SAR Processing, InSAR, Signum Coded, geodesy, geophysical measurement technique, interferometric SAR, interferometric phase pattern generation, interferometric phase patterns, land surface topography, one bit coded raw signal, quick-look DEM, radar imaging, radar remote sensing, reference function, reference signal, signal processing, spaceborne radar, synthetic aperture radar interferometry, terrain mapping, geodesy, geophysical signal processing, geophysical techniques, radar imaging, radar signal processing, remote sensing by radar, spaceborne radar, synthetic aperture radar, topography (Earth).
    Abstract: This paper is concerned about the generation of interferometric phase patterns using synthetic aperture radar (SAR) images obtained by processing the raw data and reference function both quantized at one bit (Signum Coded). Such processing technique involves one-bit coded (i.e., binary) sequences, and can be efficiently implemented in real time using very simple and low cost hardware. It is shown that the proposed SC processing technique preserves, besides the image intensities, also interferometric phase patterns, before and after phase unwrapping. To test the performance of the proposed technique, experiments have been carried out on real data relative to the ERS-1 mission. Quantitative comparison between the results of conventional and SC processing clearly show that the presented method can be used for quick-look DEMs generation. Moreover, in accordance with the SC-SAR theory, an upsampling has also been performed on the signals to be processed to obtain higher quality patterns. This produce a noticeable improvement of the obtained results, so that the SC techniques can be considered a valid alternative to the conventional ones, still preserving the advantages in terms of real time 

    @Article{628791,
Title = {Synthetic aperture radar interferometry using one bit coded raw and reference signals},
Author = {Fornaro, G. and Pascazio, V. and Schirinzi, G.},
Doi = {10.1109/36.628791},
ISSN = {0196-2892},
Month = sep,
Number = {5},
Pages = {1245 -1253},
Volume = {35},
Year = {1997},
Abstract = {This paper is concerned about the generation of interferometric phase patterns using synthetic aperture radar (SAR) images obtained by processing the raw data and reference function both quantized at one bit (Signum Coded). Such processing technique involves one-bit coded (i.e., binary) sequences, and can be efficiently implemented in real time using very simple and low cost hardware. It is shown that the proposed SC processing technique preserves, besides the image intensities, also interferometric phase patterns, before and after phase unwrapping. To test the performance of the proposed technique, experiments have been carried out on real data relative to the ERS-1 mission. Quantitative comparison between the results of conventional and SC processing clearly show that the presented method can be used for quick-look DEMs generation. Moreover, in accordance with the SC-SAR theory, an upsampling has also been performed on the signals to be processed to obtain higher quality patterns. This produce a noticeable improvement of the obtained results, so that the SC techniques can be considered a valid alternative to the conventional ones, still preserving the advantages in terms of real time},
Journal = {IEEE Transactions on Geoscience and Remote Sensing},
Keywords = {SAR Processing, InSAR;Signum Coded;geodesy;geophysical measurement technique;interferometric SAR;interferometric phase pattern generation;interferometric phase patterns;land surface topography;one bit coded raw signal;quick-look DEM;radar imaging;radar remote sensing;reference function;reference signal;signal processing;spaceborne radar;synthetic aperture radar interferometry;terrain mapping;geodesy;geophysical signal processing;geophysical techniques;radar imaging;radar signal processing;remote sensing by radar;spaceborne radar;synthetic aperture radar;topography (Earth)} 
}


  4. H. Israelsson, L. M. H. Ulander, J. L. H. Askne, J. E. S. Fransson, P.-O. Frölind, A. Gustavsson, and H. Hellsten. Retrieval of forest stem volume using VHF SAR. IEEE Trans. Geosci. Remote Sens., 35(1):36-40, January 1997. Keyword(s): SAR Processing, Forest, Forest parameters, biomass, 28 to 60 MHz, CARABAS, HF radar, Oland, SAR, Sweden, VHF radar, airborne radar, backscattering coefficient, biomass, coherent all radio band sensing, deciduous mixed forest, dense forest, discrimination, forest stem volume, forestry, geophysical measurement technique, horizontal dipole array, radar imaging, radar remote sensing, radar scattering, tree trunk, vegetation mapping, wood, airborne radar, forestry, geophysical techniques, radar cross-sections, radar imaging, remote sensing by radar, synthetic aperture radar.
    Abstract: The ability to retrieve forest stem volume using CARABAS (coherent all radio band sensing) SAR images (28-60 MHz) has been investigated. The test site is a deciduous mixed forest on the island of Oland in southern Sweden. The images have been radiometrically calibrated using an array of horizontal dipoles. The images exhibit a clear discrimination between the forest and open fields. The results show that the dynamic range of the backscattering coefficient among the forest stands is higher than what has been found with conventional SAR using microwave frequencies. The backscatter increases with increasing radar frequency. This work shows an advantage compared to higher frequencies for stem volume estimation in dense forests 

    @Article{israelssonUlanderAskneFranssonFrolindGustavssonHellsten1997:BiomassBackscatter,
Title = {Retrieval of forest stem volume using {VHF} {SAR}},
Author = {Israelsson, H. and Ulander, L. M. H. and Askne, J. L. H. and Fransson, J. E. S. and Fr\"olind, P.-O. and Gustavsson, A. and Hellsten, H.},
Doi = {10.1109/36.551932},
ISSN = {0196-2892},
Month = jan,
Number = {1},
Pages = {36-40},
Volume = {35},
Year = {1997},
Abstract = {The ability to retrieve forest stem volume using CARABAS (coherent all radio band sensing) SAR images (28-60 MHz) has been investigated. The test site is a deciduous mixed forest on the island of Oland in southern Sweden. The images have been radiometrically calibrated using an array of horizontal dipoles. The images exhibit a clear discrimination between the forest and open fields. The results show that the dynamic range of the backscattering coefficient among the forest stands is higher than what has been found with conventional SAR using microwave frequencies. The backscatter increases with increasing radar frequency. This work shows an advantage compared to higher frequencies for stem volume estimation in dense forests},
Journal = {IEEE Trans. Geosci. Remote Sens.},
Keywords = {SAR Processing, Forest, Forest parameters, biomass, 28 to 60 MHz;CARABAS;HF radar;Oland;SAR;Sweden;VHF radar;airborne radar;backscattering coefficient;biomass;coherent all radio band sensing;deciduous mixed forest;dense forest;discrimination;forest stem volume;forestry;geophysical measurement technique;horizontal dipole array;radar imaging;radar remote sensing;radar scattering;tree trunk;vegetation mapping;wood;airborne radar;forestry;geophysical techniques;radar cross-sections;radar imaging;remote sensing by radar;synthetic aperture radar} 
}


  5. Riccardo Lanari and Gianfranco Fornaro. A short discussion on the exact compensation of the SAR range-dependent range cell migration effect. IEEE Transactions on Geoscience and Remote Sensing, 35(6):1446-1452, November 1997. Keyword(s): SAR Processing, Motion Compensation, Comparison of Algorithms, Chirp Scaling Algorithm, Range Cell Migration, Range Migration, FM radar, geophysical signal processing, geophysical techniques, radar imaging, remote sensing by radar, synthetic aperture radar, RCM, RDRCM, SAR, chirp z-transform, exact compensation, geophysical measurement technique, land surface, radar remote sensing, range-dependent range cell migration effect, terrain mapping.
    Abstract: Efficient and precise compensation of the range cell migration (RCM) effect is a key point for a fast and accurate synthetic aperture radar (SAR) data processor. In particular the range-dependent nature of the range cell migration effect complicates the compensation operation. It has been recently shown that an exact compensation of the range-dependent RCM (RDRCM) phenomenon can be carried out either by applying the chirp scaling algorithm or the chirp z-transform procedure. This paper investigates the relationship between the two methods. In particular, it is shown that the chirp z-transform based approach represents a particular implementation of the chirp scaling algorithm. A final discussion is dedicated to show how the chirp z-transform and the chirp scaling procedure can be applied within a SAR data processing algorithm. 

    @Article{LanariFornaro1997:MoCoDiscussion,
author = {Lanari, Riccardo and Fornaro, Gianfranco},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
title = {{A short discussion on the exact compensation of the SAR range-dependent range cell migration effect}},
year = {1997},
month = {nov},
number = {6},
pages = {1446-1452},
volume = {35},
abstract = {Efficient and precise compensation of the range cell migration (RCM) effect is a key point for a fast and accurate synthetic aperture radar (SAR) data processor. In particular the range-dependent nature of the range cell migration effect complicates the compensation operation. It has been recently shown that an exact compensation of the range-dependent RCM (RDRCM) phenomenon can be carried out either by applying the chirp scaling algorithm or the chirp z-transform procedure. This paper investigates the relationship between the two methods. In particular, it is shown that the chirp z-transform based approach represents a particular implementation of the chirp scaling algorithm. A final discussion is dedicated to show how the chirp z-transform and the chirp scaling procedure can be applied within a SAR data processing algorithm.},
keywords = {SAR Processing, Motion Compensation, Comparison of Algorithms, Chirp Scaling Algorithm, Range Cell Migration, Range Migration, FM radar, geophysical signal processing, geophysical techniques, radar imaging, remote sensing by radar, synthetic aperture radar, RCM, RDRCM, SAR, chirp z-transform, exact compensation, geophysical measurement technique, land surface, radar remote sensing, range-dependent range cell migration effect, terrain mapping},
owner = {ofrey},
pdf = {../../../docs/LanariFornaro1997.pdf},
url = {http://ieeexplore.ieee.org/iel3/36/14159/00649799.pdf},

}


  6. J. Li, Z. Bi, Z.S. Liu, and K. Knaell. Use of curvilinear SAR for three-dimensional target feature extraction. Radar, Sonar and Navigation, IEE Proceedings-, 144(5):275-283, 1997. Keyword(s): SAR Processing, Non-Linear Flight Path, SAR Tomography, Feature Extraction, Target Feature Extraction, Curvilinear SAR. 
    @Article{liBiLiuKnaell1997:NonLinearSARTomo,
Title = {{Use of curvilinear SAR for three-dimensional target feature extraction}},
Author = {Li, J. and Bi, Z. and Liu, Z.S. and Knaell, K.},
Number = {5},
Pages = {275--283},
Url = {http://ieeexplore.ieee.org/iel3/2198/13771/00635859.pdf},
Volume = {144},
Year = {1997},
Journal = {Radar, Sonar and Navigation, IEE Proceedings-},
Keywords = {SAR Processing, Non-Linear Flight Path, SAR Tomography, Feature Extraction, Target Feature Extraction, Curvilinear SAR},
Pdf = {../../../docs/liBiLiuKnaell1997.pdf} 
}


  7. J. Li, Z.-S. Liu, and Petre Stoica. 3-D target feature extraction via interferometric SAR. Radar, Sonar and Navigation, IEE Proceedings -, 144(2):71-80, 1997. Keyword(s): SAR Processing, Tomography, SAR Tomography, InSAR, fast Fourier transforms, feature extraction, least squares approximations, parameter estimation, radar cross-sections, radar signal processing, radiowave interferometry, signal resolution, synthetic aperture radar, 3D target feature extraction, Capon, Cramer-Rao bounds, FTF, IFRELAX, IFSAR, MUSIC, data model, interferometric SAR, interferometric synthetic aperture radar, nonlinear least squares parameter estimation method, nonparametric methods, parameter estimates, parameter identifiability conditions, performance, point scatterers, two-dimensional feature extraction methods, windowed FFT.
    Abstract: The authors consider 3-D (three-dimensional) target feature extraction via an interferometric synthetic aperture radar (IFSAR). The targets of interest are relatively small and consist of a small number of distinct point scatterers. Since using IFSAR to extract the features of such targets has not been addressed before, a self-contained detailed derivation of the data model is presented. A set of sufficient parameter identifiability conditions on the data model and the Cramer-Rao bounds (CRBs) on the parameter estimates are also derived. Four existing two-dimensional feature extraction methods (FFT, windowed FFT, Capon and MUSIC) are extended to estimate the 3-D parameters of the target scatterers. A new nonlinear least squares parameter estimation method, referred to as IFRELAX, is also derived to extract the target features. Finally, numerical examples are presented to compare the performances of the presented methods with each other and with the corresponding CRBs.The authors show by means of numerical examples that, among the three nonparametric methods (FFT, windowed FFT, and Capon), Capon has the best resolution. The parametric methods MUSIC and IFRELAX can have much better resolution and provide much more accurate parameter estimates than the nonparametric methods. It is shown IFRELAX can be faster and provide much better parameter estimates than MUSIC. 

    @Article{liLiuStoica97:Tomography,
Title = {3-D target feature extraction via interferometric SAR},
Author = {Li, J. and Liu, Z.-S. and Stoica, Petre},
ISSN = {1350-2395},
Number = {2},
Pages = {71--80},
Url = {http://ieeexplore.ieee.org/iel1/2198/12824/00591257.pdf},
Volume = {144},
Year = {1997},
Abstract = {The authors consider 3-D (three-dimensional) target feature extraction via an interferometric synthetic aperture radar (IFSAR). The targets of interest are relatively small and consist of a small number of distinct point scatterers. Since using IFSAR to extract the features of such targets has not been addressed before, a self-contained detailed derivation of the data model is presented. A set of sufficient parameter identifiability conditions on the data model and the Cramer-Rao bounds (CRBs) on the parameter estimates are also derived. Four existing two-dimensional feature extraction methods (FFT, windowed FFT, Capon and MUSIC) are extended to estimate the 3-D parameters of the target scatterers. A new nonlinear least squares parameter estimation method, referred to as IFRELAX, is also derived to extract the target features. Finally, numerical examples are presented to compare the performances of the presented methods with each other and with the corresponding CRBs.The authors show by means of numerical examples that, among the three nonparametric methods (FFT, windowed FFT, and Capon), Capon has the best resolution. The parametric methods MUSIC and IFRELAX can have much better resolution and provide much more accurate parameter estimates than the nonparametric methods. It is shown IFRELAX can be faster and provide much better parameter estimates than MUSIC.},
Journal = {Radar, Sonar and Navigation, IEE Proceedings -},
Keywords = {SAR Processing, Tomography, SAR Tomography, InSAR, fast Fourier transforms, feature extraction, least squares approximations, parameter estimation, radar cross-sections, radar signal processing, radiowave interferometry, signal resolution, synthetic aperture radar, 3D target feature extraction, Capon, Cramer-Rao bounds, FTF, IFRELAX, IFSAR, MUSIC, data model, interferometric SAR, interferometric synthetic aperture radar, nonlinear least squares parameter estimation method, nonparametric methods, parameter estimates, parameter identifiability conditions, performance, point scatterers, two-dimensional feature extraction methods, windowed FFT},
Owner = {ofrey},
Pdf = {../../../docs/liLiuStoica97.pdf} 
}


  8. T. Miller, L. Potter, and John W. McCorkle. RFI suppression for ultra wideband radar. Aerospace and Electronic Systems, IEEE Transactions on, 33(4):1142-1156, 1997. Keyword(s): SAR Processing, interference suppression, least squares approximations, radar imaging, radar interference, radiofrequency interference, synthetic aperture radar, Army Research Laboratory, RFI Suppression, SAR imagery, UWB rail SAR, bias, estimate-and-subtract algorithm, estimated targets, foliage-penetrating imaging, ground-penetrating imaging, radio frequency interference, real-time digital suppression, sidelobe levels, signal model, target energy loss, ultra wideband radar, ultrawideband synthetic aperture radar.
    Abstract: An estimate-and-subtract algorithm is presented for the real-time 

    @Article{millerPotterMcCorkle97:RFI,
Title = {RFI suppression for ultra wideband radar},
Author = {Miller, T. and Potter, L. and McCorkle, John W.},
Number = {4},
Pages = {1142--1156},
Url = {http://ieeexplore.ieee.org/iel4/7/13583/00625096.pdf},
Volume = {33},
Year = {1997},
Abstract = {An estimate-and-subtract algorithm is presented for the real-time},
Journal = {Aerospace and Electronic Systems, IEEE Transactions on},
Keywords = {SAR Processing, interference suppression, least squares approximations, radar imaging, radar interference, radiofrequency interference, synthetic aperture radar, Army Research Laboratory, RFI Suppression, SAR imagery, UWB rail SAR, bias, estimate-and-subtract algorithm, estimated targets, foliage-penetrating imaging, ground-penetrating imaging, radio frequency interference, real-time digital suppression, sidelobe levels, signal model, target energy loss, ultra wideband radar, ultrawideband synthetic aperture radar},
Owner = {ofrey},
Pdf = {../../../docs/millerPotterMcCorkle97.pdf} 
}


  9. Andrea Monti-Guarnieri and C. Prati. SAR interferometry: A ``Quick and dirty'' coherence estimator for data browsing. IEEE Transactions on Geoscience and Remote Sensing, 35(3):660-669, May 1997. Keyword(s): SAR Processing, Coherence, Coherence Estimation, geophysical signal processing, geophysical techniques, radar imaging, remote sensing by radar, spaceborne radar, speckle, synthetic aperture radarERS, SAR interferometry, coherence estimator, coherence map, data browsing, fast algorithm, geophysical measurement technique, land surface, quick method, radar remote sensing, speckle similarity, synthetic aperture radar, terrain mapping.
    Abstract: Usual coherence estimation in SAR interferometry is a time consuming task since an accurate estimation of the local frequency of the interferometric fringes is required. This paper presents a fast algorithm for generating coherence maps, mainly intended for data browsing. The proposed estimator is based on the speckle similarity of coherent SAR data, and is thus independent of fringe frequency. The following advantages, with respect to the usual estimates, are achieved: (a) The estimator is more than 100 times faster, achieved at the cost of a reduced statistical confidence. (b) The estimator is not affected by possible local frequency estimation errors. (c) The estimator can be directly applied to single look detected images. The theoretical derivation of the statistical properties of the frequency independent estimator is carried out in the stationary case. The nonstationary case is then analyzed on real ERS SAR images 

    @Article{montiGuarnieriPrati97:Coherence,
author = {Monti-Guarnieri, Andrea and Prati, C.},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
title = {{SAR interferometry: A ``Quick and dirty'' coherence estimator for data browsing}},
year = {1997},
month = may,
number = {3},
pages = {660-669},
volume = {35},
abstract = {Usual coherence estimation in SAR interferometry is a time consuming task since an accurate estimation of the local frequency of the interferometric fringes is required. This paper presents a fast algorithm for generating coherence maps, mainly intended for data browsing. The proposed estimator is based on the speckle similarity of coherent SAR data, and is thus independent of fringe frequency. The following advantages, with respect to the usual estimates, are achieved: (a) The estimator is more than 100 times faster, achieved at the cost of a reduced statistical confidence. (b) The estimator is not affected by possible local frequency estimation errors. (c) The estimator can be directly applied to single look detected images. The theoretical derivation of the statistical properties of the frequency independent estimator is carried out in the stationary case. The nonstationary case is then analyzed on real ERS SAR images},
doi = {10.1109/36.581984},
keywords = {SAR Processing, Coherence, Coherence Estimation, geophysical signal processing, geophysical techniques, radar imaging, remote sensing by radar, spaceborne radar, speckle, synthetic aperture radarERS, SAR interferometry, coherence estimator, coherence map, data browsing, fast algorithm, geophysical measurement technique, land surface, quick method, radar remote sensing, speckle similarity, synthetic aperture radar, terrain mapping},
pdf = {../../../docs/montiGuarnieriPrati97},
url = {http://ieeexplore.ieee.org/iel1/36/12630/00581984.pdf},

}


  10. Tazio Strozzi, Andreas Wiesmann, and Christian Matzler. Active microwave signatures of snow covers at 5.3 and 35 GHz. Radio Science, 32(2):479-495, 1997. Keyword(s): microwave signatures, Snow, Remote Sensing of Snow, C-band, Ka-band, Electromagnetics.
    Abstract: During the last 3 years we performed in situ backscattering measurements on various natural snow covers at 5.3 and 35 GHz (C and Ka band, respectively). Most of the measurements were made at a test site above Davos in the Swiss Alps at 2540 m above sea level (asl), but studies were conducted also at other test sites in Switzerland and Austria at heights between 500 and 2200 m asl. The backscattering coefficient gamma was measured at hh, vv, hv and vh polarization, together with physical parameters of the snow cover, like snow height, stratification, temperature, density, and permittivity. On the basis of ground information and on a simple distribution of gamma, we identified signatures of object classes. The signatures were used in order to evaluate the capability of active microwave sensors at 5.3 and 35 GHz for the classification of snow covers. In addition, semiempirical algorithms for the retrieval of physical parameters of the snow cover, such as water equivalent, liquid water content, and thickness of the refrozen crust, were defined. 

    @Article{strozziWiesmannMatzlerRADIOSCIENCE1997Snow,
author = {Strozzi, Tazio and Wiesmann, Andreas and Matzler, Christian},
title = {Active microwave signatures of snow covers at 5.3 and 35 GHz},
journal = {Radio Science},
year = {1997},
volume = {32},
number = {2},
pages = {479--495},
issn = {1944-799X},
abstract = {During the last 3 years we performed in situ backscattering measurements on various natural snow covers at 5.3 and 35 GHz (C and Ka band, respectively). Most of the measurements were made at a test site above Davos in the Swiss Alps at 2540 m above sea level (asl), but studies were conducted also at other test sites in Switzerland and Austria at heights between 500 and 2200 m asl. The backscattering coefficient gamma was measured at hh, vv, hv and vh polarization, together with physical parameters of the snow cover, like snow height, stratification, temperature, density, and permittivity. On the basis of ground information and on a simple distribution of gamma, we identified signatures of object classes. The signatures were used in order to evaluate the capability of active microwave sensors at 5.3 and 35 GHz for the classification of snow covers. In addition, semiempirical algorithms for the retrieval of physical parameters of the snow cover, such as water equivalent, liquid water content, and thickness of the refrozen crust, were defined.},
doi = {10.1029/96RS03777},
file = {:strozziWiesmannMatzlerRADIOSCIENCE1997Snow.pdf:PDF},
keywords = {microwave signatures, Snow, Remote Sensing of Snow, C-band, Ka-band, Electromagnetics},
owner = {ofrey},
pdf = {../../../docs/strozziWiesmannMatzlerRADIOSCIENCE1997Snow.pdf},
url = {http://dx.doi.org/10.1029/96RS03777},

}


  11. Howard A. Zebker, Paul A. Rosen, and Scott Hensley. Atmospheric effects in interferometric synthetic aperture radar surface deformation and topographic maps. Journal of Geophysical Research: Solid Earth, 102(B4):7547-7563, 1997. Keyword(s): Remote sensing, Instruments and techniquesInstruments and techniques.
    Abstract: Interferogram images derived from repeat-pass spaceborne synthetic aperture radar systems exhibit artifacts due to the time and space variations of atmospheric water vapor. Other tropospheric variations, such as pressure and temperature, also induce distortions, but the effects are smaller in magnitude and more evenly distributed throughout the interferogram than the wet troposphere term. Spatial and temporal changes of 20% in relative humidity lead to 10 cm errors in deformation products, and perhaps 100 m of error in derived topographic maps for those pass pairs with unfavorable baseline geometries. In wet regions such as Hawaii, these are by far the dominant errors in the Spaceborne Imaging Radar-C and X Band Synthetic Aperature Radar (SIR-C/X-SAR) interferometric products. The unknown time delay from tropospheric distortion is independent of frequency, and thus multiwavelength measurements, such as those commonly used to correct radar altimeter and Global Positioning System (GPS) ionospheric biases, cannot be used to rectify the error. In the topographic case, the errors may be mitigated by choosing interferometric pairs with relatively long baselines, as the error amplitude is inversely proportional to the perpendicular component of the interferometer baseline. For the SIR-C/X-SAR Hawaii data we found that the best (longest) baseline pair produced a map supporting 100 m contouring, whereas the poorest baseline choice yielded an extremely noisy topographic map even at this coarse contour interval. In the case of deformation map errors the result is either independent of baseline parameters or else very nearly so. Here the only solution is averaging of independent interferograms, so in order to create accurate deformation products in wet regions many multiple passes may be required. Rules for designing optimal data acquisition and processing sequences for interferometric analyses in nondesert parts of the world are (1) to use the longest radar wavelengths possible, within ionospheric scintillation and Faraday rotation limits, (2) for topography, maximize interferometer baseline within decorrelation limits and (3) for surface deformation, use multiple observations and average the derived products. Following the above recipe yields accuracies of 10 m for digital elevation models and 1 cm for deformation maps even in very wet regions, such as Hawaii. 

    @Article{zebkerRosenHensleyJGRB1997AtmosphereDInSAR,
author = {Zebker, Howard A. and Rosen, Paul A. and Hensley, Scott},
title = {Atmospheric effects in interferometric synthetic aperture radar surface deformation and topographic maps},
journal = {Journal of Geophysical Research: Solid Earth},
year = {1997},
volume = {102},
number = {B4},
pages = {7547--7563},
issn = {2156-2202},
abstract = {Interferogram images derived from repeat-pass spaceborne synthetic aperture radar systems exhibit artifacts due to the time and space variations of atmospheric water vapor. Other tropospheric variations, such as pressure and temperature, also induce distortions, but the effects are smaller in magnitude and more evenly distributed throughout the interferogram than the wet troposphere term. Spatial and temporal changes of 20% in relative humidity lead to 10 cm errors in deformation products, and perhaps 100 m of error in derived topographic maps for those pass pairs with unfavorable baseline geometries. In wet regions such as Hawaii, these are by far the dominant errors in the Spaceborne Imaging Radar-C and X Band Synthetic Aperature Radar (SIR-C/X-SAR) interferometric products. The unknown time delay from tropospheric distortion is independent of frequency, and thus multiwavelength measurements, such as those commonly used to correct radar altimeter and Global Positioning System (GPS) ionospheric biases, cannot be used to rectify the error. In the topographic case, the errors may be mitigated by choosing interferometric pairs with relatively long baselines, as the error amplitude is inversely proportional to the perpendicular component of the interferometer baseline. For the SIR-C/X-SAR Hawaii data we found that the best (longest) baseline pair produced a map supporting 100 m contouring, whereas the poorest baseline choice yielded an extremely noisy topographic map even at this coarse contour interval. In the case of deformation map errors the result is either independent of baseline parameters or else very nearly so. Here the only solution is averaging of independent interferograms, so in order to create accurate deformation products in wet regions many multiple passes may be required. Rules for designing optimal data acquisition and processing sequences for interferometric analyses in nondesert parts of the world are (1) to use the longest radar wavelengths possible, within ionospheric scintillation and Faraday rotation limits, (2) for topography, maximize interferometer baseline within decorrelation limits and (3) for surface deformation, use multiple observations and average the derived products. Following the above recipe yields accuracies of 10 m for digital elevation models and 1 cm for deformation maps even in very wet regions, such as Hawaii.},
doi = {10.1029/96JB03804},
file = {:zebkerRosenHensleyJGRB1997AtmosphereDInSAR.pdf:PDF},
keywords = {Remote sensing, Instruments and techniquesInstruments and techniques},
pdf = {../../../docs/zebkerRosenHensleyJGRB1997AtmosphereDInSAR.pdf},
url = {http://dx.doi.org/10.1029/96JB03804},

}


Conference articles

  1. F. Berizzi, G. Corsini, M. Diani, F. Lombardini, and G. Pinelli. Simulation model and performance analysis of a three-antenna InSAR system. In Radar 97 (Conf. Publ. No. 449), pages 119-123, October 1997. 
    @InProceedings{Berizzi1997,
Title = {Simulation model and performance analysis of a three-antenna InSAR system},
Author = {Berizzi, F. and Corsini, G. and Diani, M. and Lombardini, F. and Pinelli, G.},
Booktitle = {Radar 97 (Conf. Publ. No. 449)},
Month = oct,
Pages = {119--123},
Year = {1997},
Owner = {ofrey} 
}


  2. Tsz-King Chan, Y. Kuga, and A. Ishimaru. Feasibility study on localized subsurface imaging using circular synthetic aperture radar and angular correlation function measurement. In Proc. IEEE Int. Geosci. Remote Sens. Symp., volume 3, pages 1138-1140 vol.3, August 1997. Keyword(s): SAR Processing, W-Band, airborne radar, geophysical techniques, radar imaging, remote sensing by radar, synthetic aperture radar, terrestrial electricity, 3D imaging, 7 to 13 GHz, 75 to 100 GHz, CSAR, EHF, SAR, SHF, W-band, X-band, airborne radar, angular correlation function, buried object detection, circular angular memory effect, circular flight path, circular synthetic aperture radar, confocally focused plane, down-looking spotlight mode, geoelectric method, geology, geophysical measurement technique, ground penetrating radar, localized subsurface imaging, radar imaging, radar remote sensing, subsurface structure, terrestrial electricity, High-resolution imaging, Image reconstruction, Image resolution, Laboratories, Pixel, Radar antennas, Radar applications, Radar imaging, Signal resolution, Signal to noise ratio.
    Abstract: The traditional linear synthetic aperture radar (LSAR) flying along a linear flight path is modified to circular synthetic aperture radar (CSAR) flying along a circular flight path. When operating in down-looking spotlight mode for imaging purposes, CSAR, in comparison with LSAR, can provide higher pixel resolutions on any confocally focused plane within the volume illuminated by the antenna beams. By combining this 3D imaging technique with the circular angular memory effect, it is possible to reconstruct volume radar images in localized subsurface imaging applications where poor signal-to-noise ratio (SNR) is a critical issue. Laboratory experiments at X-band (7-13 GHz) and W-band (75-100 GHz) frequencies were conducted to illustrate the capability of CSAR to perform 3D imaging, and the analytical basis of circular angular memory effect due to random surface scattering based on the first-order Kirchhoff approximation 

    @INPROCEEDINGS{chanKugaIshimaruIGARSS1997WBandSAR,
author={Tsz-King Chan and Y. Kuga and A. Ishimaru},
booktitle={Proc. IEEE Int. Geosci. Remote Sens. Symp.},
title={Feasibility study on localized subsurface imaging using circular synthetic aperture radar and angular correlation function measurement},
year={1997},
volume={3},
number={},
pages={1138-1140 vol.3},
abstract={The traditional linear synthetic aperture radar (LSAR) flying along a linear flight path is modified to circular synthetic aperture radar (CSAR) flying along a circular flight path. When operating in down-looking spotlight mode for imaging purposes, CSAR, in comparison with LSAR, can provide higher pixel resolutions on any confocally focused plane within the volume illuminated by the antenna beams. By combining this 3D imaging technique with the circular angular memory effect, it is possible to reconstruct volume radar images in localized subsurface imaging applications where poor signal-to-noise ratio (SNR) is a critical issue. Laboratory experiments at X-band (7-13 GHz) and W-band (75-100 GHz) frequencies were conducted to illustrate the capability of CSAR to perform 3D imaging, and the analytical basis of circular angular memory effect due to random surface scattering based on the first-order Kirchhoff approximation},
keywords={SAR Processing, W-Band, airborne radar;geophysical techniques;radar imaging;remote sensing by radar;synthetic aperture radar;terrestrial electricity;3D imaging;7 to 13 GHz;75 to 100 GHz;CSAR;EHF;SAR;SHF;W-band;X-band;airborne radar;angular correlation function;buried object detection;circular angular memory effect;circular flight path;circular synthetic aperture radar;confocally focused plane;down-looking spotlight mode;geoelectric method;geology;geophysical measurement technique;ground penetrating radar;localized subsurface imaging;radar imaging;radar remote sensing;subsurface structure;terrestrial electricity;High-resolution imaging;Image reconstruction;Image resolution;Laboratories;Pixel;Radar antennas;Radar applications;Radar imaging;Signal resolution;Signal to noise ratio},
doi={10.1109/IGARSS.1997.606376},
ISSN={},
month=aug,
owner = {ofrey},

}


  3. G. Connan, H. D. Griffiths, and P. V. Brennan. FMCW-SAR development for internal wave imaging. In OCEANS '97. MTS/IEEE Conference Proceedings, volume 1, pages 73-78 vol.1, October 1997. Keyword(s): SAR Processing, W-Band, CW radar, FM radar, electromagnetic wave scattering, oceanographic equipment, oceanographic techniques, radar cross-sections, radar equipment, radar imaging, radar polarimetry, remote sensing by radar, synthetic aperture radar, 94 GHz, EHF, FMCW radar, MORSE, Mesoscale Ocean Radar Signature Experiments, SAR, W-band, internal wave, measurement technique, millimetre wave radar, millimetric radar, mm wave, model, ocean dynamics, radar imaging, radar polarimetry, radar remote sensing, synthetic aperture imaging, synthetic aperture radar, ultra-high-resolution SAR, Azimuth, Hydrodynamics, Laboratories, Laser radar, Radar antennas, Radar imaging, Sea surface, Spaceborne radar, Surface topography, Surface waves.
    Abstract: The observation of internal waves in SAR images is not new but the imaging mechanisms involved are not fully understood. The Mesoscale Ocean Radar Signature Experiments (MORSE) project aims to provide models of these processes, both by theoretical and experimental means. As part of this work, a laboratory-based advanced ultra-high-resolution SAR is being developed to obtain images of the water surface in scaled experiments. The radar, which has a polarimetric capability, operates at a frequency of 94 GHz and uses the FMCW technique, with a range resolution of 5 cm and an azimuth resolution of 1 cm for an imaged area of 5x4 m2. This SAR is to be used in a set of experiments in LEGI, France, first in a flume, and then in a wave tank in which scaled versions of particular internal wave phenomena can be set-up under laboratory conditions. This paper will particularly focus on the development of this radar 

    @InProceedings{connanGriffithsBrennanOCEANS1997FMCWSARWBAND,
author = {G. Connan and H. D. Griffiths and P. V. Brennan},
booktitle = {OCEANS '97. MTS/IEEE Conference Proceedings},
title = {FMCW-SAR development for internal wave imaging},
year = {1997},
month = oct,
pages = {73-78 vol.1},
volume = {1},
abstract = {The observation of internal waves in SAR images is not new but the imaging mechanisms involved are not fully understood. The Mesoscale Ocean Radar Signature Experiments (MORSE) project aims to provide models of these processes, both by theoretical and experimental means. As part of this work, a laboratory-based advanced ultra-high-resolution SAR is being developed to obtain images of the water surface in scaled experiments. The radar, which has a polarimetric capability, operates at a frequency of 94 GHz and uses the FMCW technique, with a range resolution of 5 cm and an azimuth resolution of 1 cm for an imaged area of 5x4 m2. This SAR is to be used in a set of experiments in LEGI, France, first in a flume, and then in a wave tank in which scaled versions of particular internal wave phenomena can be set-up under laboratory conditions. This paper will particularly focus on the development of this radar},
doi = {10.1109/OCEANS.1997.634338},
keywords = {SAR Processing, W-Band, CW radar;FM radar;electromagnetic wave scattering;oceanographic equipment;oceanographic techniques;radar cross-sections;radar equipment;radar imaging;radar polarimetry;remote sensing by radar;synthetic aperture radar;94 GHz;EHF;FMCW radar;MORSE;Mesoscale Ocean Radar Signature Experiments;SAR;W-band;internal wave;measurement technique;millimetre wave radar;millimetric radar;mm wave;model;ocean dynamics;radar imaging;radar polarimetry;radar remote sensing;synthetic aperture imaging;synthetic aperture radar;ultra-high-resolution SAR;Azimuth;Hydrodynamics;Laboratories;Laser radar;Radar antennas;Radar imaging;Sea surface;Spaceborne radar;Surface topography;Surface waves},
owner = {ofrey},

}


  4. G. Corsini, M. Diani, F. Lombardini, and G. Pinelli. Reduction of the phase-unwrapping drawbacks by the three-antenna interferometric SAR system. In Geoscience and Remote Sensing, 1997. IGARSS '97. 'Remote Sensing - A Scientific Vision for Sustainable Development'., 1997 IEEE International, volume 4, pages 1536-1538, August 1997. 
    @InProceedings{Corsini1997,
Title = {Reduction of the phase-unwrapping drawbacks by the three-antenna interferometric SAR system},
Author = {Corsini, G. and Diani, M. and Lombardini, F. and Pinelli, G.},
Booktitle = {Geoscience and Remote Sensing, 1997. IGARSS '97. 'Remote Sensing - A Scientific Vision for Sustainable Development'., 1997 IEEE International},
Doi = {10.1109/IGARSS.1997.608933},
Month = aug,
Pages = {1536--1538},
Volume = {4},
Year = {1997},
Owner = {ofrey} 
}


  5. N.E. Doren, C.V. Jakowatz, D.E. Wahl, and P.A. Thompson. General formulation for wavefront curvature correction in polar-formatted spotlight-mode SAR images using space-variant post-filtering. In Proceedings of International Conference on Image Processing, volume 1, pages 861-864 vol.1, October 1997. Keyword(s): Layout, Fourier transforms, Image reconstruction, Radar imaging, Filters, Frequency, History, US Department of Energy, Reflectivity, Microwave theory and techniques.
    Abstract: We introduce a general formulation for wavefront curvature correction in spotlight-mode SAR images formed using the polar-formatting algorithm (PFA). This correction is achieved through the use of an efficient, image domain space-variant filter which is applied as a post-processing step to the PFA. Wavefront curvature defocus effects occur in certain SAR collection modes that include imaging at close range, using a low center frequency, and/or imaging very large scenes. Our formulation is general in that it corrects for wavefront curvature in broadside as well as squinted collection modes, with no computational penalty for correcting squint-mode images. Algorithms such as the range migration technique (also known as seismic migration), and an enhancement known as frequency domain replication, FReD, have been developed to accommodate these wavefront curvature effects. However, they exhibit no clear computational advantage over space-variant post-filtering in conjunction with polar formatting (PF2). This paper presents the basic concepts of the formulation, and provides computer results demonstrating the capabilities of space-variant post-filtering. 

    @InProceedings{Doren1997,
author = {Doren, N.E. and Jakowatz, C.V. and Wahl, D.E. and Thompson, P.A.},
booktitle = {Proceedings of International Conference on Image Processing},
title = {General formulation for wavefront curvature correction in polar-formatted spotlight-mode SAR images using space-variant post-filtering},
year = {1997},
month = {Oct},
pages = {861-864 vol.1},
volume = {1},
abstract = {We introduce a general formulation for wavefront curvature correction in spotlight-mode SAR images formed using the polar-formatting algorithm (PFA). This correction is achieved through the use of an efficient, image domain space-variant filter which is applied as a post-processing step to the PFA. Wavefront curvature defocus effects occur in certain SAR collection modes that include imaging at close range, using a low center frequency, and/or imaging very large scenes. Our formulation is general in that it corrects for wavefront curvature in broadside as well as squinted collection modes, with no computational penalty for correcting squint-mode images. Algorithms such as the range migration technique (also known as seismic migration), and an enhancement known as frequency domain replication, FReD, have been developed to accommodate these wavefront curvature effects. However, they exhibit no clear computational advantage over space-variant post-filtering in conjunction with polar formatting (PF2). This paper presents the basic concepts of the formulation, and provides computer results demonstrating the capabilities of space-variant post-filtering.},
doi = {10.1109/ICIP.1997.648102},
keywords = {Layout;Fourier transforms;Image reconstruction;Radar imaging;Filters;Frequency;History;US Department of Energy;Reflectivity;Microwave theory and techniques},
owner = {ofrey},

}


  6. C.V. Jakowatz, D.E. Wahl, and P.A. Thompson. Three-dimensional SAR imaging using cross-track coherent stereo collections. In Conference Record of the Thirty-First Asilomar Conference on Signals, Systems and Computers (Cat. No.97CB36136), volume 2, pages 1199-1203 vol.2, November 1997. Keyword(s): Radar polarimetry, Aircraft, Synthetic aperture radar, Lighting, Optical imaging, Optical films, Layout, Geometry, Laboratories, Speckle.
    Abstract: We describe a new method for creating three-dimensional images using pairs of synthetic aperture radar (SAR) images obtained from a unique collection geometry. This collection mode involves synthetic apertures that have a common center. In this sense the illumination directions for the two SAR images are the same, while the slant planes are at different spatial orientations. The slant plane orientations give rise to cross-range layover (fore-shortening) components in the two images that are of equal magnitude but opposite directions. This differential cross-range layover is therefore proportional to the elevation of a given target, which is completely analogous to the situation in stereo optical imaging, wherein two film planes (corresponding to the two slant planes) result in elevation-dependent parallax. Because the two SAR collections are coherent in this particular collection mode, the images have the same speckle patterns throughout. As a result the images may be placed into stereo correspondence via calculation of correlations between micro-patches of the complex image data. The resulting computed digital stereo elevation map can be quite accurate. Alternatively, an analog anaglyph can be displayed for 3-D viewing, avoiding the necessity of the stereo correspondence calculation. 

    @InProceedings{Jakowatz1997,
author = {Jakowatz, C.V. and Wahl, D.E. and Thompson, P.A.},
booktitle = {Conference Record of the Thirty-First Asilomar Conference on Signals, Systems and Computers (Cat. No.97CB36136)},
title = {Three-dimensional SAR imaging using cross-track coherent stereo collections},
year = {1997},
month = {Nov},
pages = {1199-1203 vol.2},
volume = {2},
abstract = {We describe a new method for creating three-dimensional images using pairs of synthetic aperture radar (SAR) images obtained from a unique collection geometry. This collection mode involves synthetic apertures that have a common center. In this sense the illumination directions for the two SAR images are the same, while the slant planes are at different spatial orientations. The slant plane orientations give rise to cross-range layover (fore-shortening) components in the two images that are of equal magnitude but opposite directions. This differential cross-range layover is therefore proportional to the elevation of a given target, which is completely analogous to the situation in stereo optical imaging, wherein two film planes (corresponding to the two slant planes) result in elevation-dependent parallax. Because the two SAR collections are coherent in this particular collection mode, the images have the same speckle patterns throughout. As a result the images may be placed into stereo correspondence via calculation of correlations between micro-patches of the complex image data. The resulting computed digital stereo elevation map can be quite accurate. Alternatively, an analog anaglyph can be displayed for 3-D viewing, avoiding the necessity of the stereo correspondence calculation.},
doi = {10.1109/ACSSC.1997.679094},
issn = {1058-6393},
keywords = {Radar polarimetry;Aircraft;Synthetic aperture radar;Lighting;Optical imaging;Optical films;Layout;Geometry;Laboratories;Speckle},
owner = {ofrey},

}


  7. Charles V. Jakowatz, Daniel E. Wahl, Paul A. Thompson, and Neall E. Doren. Space-variant filtering for correction of wavefront curvature effects in spotlight-mode SAR imagery formed via polar formatting. In Edmund G. Zelnio, editor, , volume 3070, pages 33-42, 1997. SPIE. Keyword(s): SAR Processing, Polar Format Algorithm, PFA, Range Migration Algorithm, RMA, omega-k, correction of wavefront curvature effects, Spotlight SAR, Spotlight-mode data. 
    @Conference{jakowatzWahlThompsonDorenSpotlightPolarFormat1997,
author = {Charles V. Jakowatz and Daniel E. Wahl and Paul A. Thompson and Neall E. Doren},
title = {Space-variant filtering for correction of wavefront curvature effects in spotlight-mode {SAR} imagery formed via polar formatting},
year = {1997},
editor = {Edmund G. Zelnio},
number = {1},
pages = {33-42},
publisher = {SPIE},
volume = {3070},
doi = {10.1117/12.281576},
file = {:jakowatzWahlThompsonDorenSpotlightPolarFormat1997.pdf:PDF},
journal = {Algorithms for Synthetic Aperture Radar Imagery IV},
keywords = {SAR Processing, Polar Format Algorithm, PFA, Range Migration Algorithm, RMA, omega-k, correction of wavefront curvature effects, Spotlight SAR, Spotlight-mode data},
location = {Orlando, FL, USA},
owner = {ofrey},
pdf = {../../../docs/jakowatzWahlThompsonDorenSpotlightPolarFormat1997.pdf},
url = {http://link.aip.org/link/?PSI/3070/33/1},

}


  8. Michael Y. Jin. High Quality Spotlight SAR Processing Algorithm Designed for LightSAR Mission. In IGARSS '97, International Geoscience and Remote Sensing Symposium, volume 29, pages 477-480, August 1997. Keyword(s): SAR Processing, Subband Images, LightSAR, SIR-C, Spotlight SAR.
    Abstract: A high quality spotlight SAR processing algorithm is presented. In this algorithm, subband images of the radar illuminated spot are processed using well known strip mode processing algorithms. A full resolution image is then formed by (1) merging the spectra of subband images into a full band spectrum, and (2) taking an inverse FFT. Advantages of this algorithm include (1) higher image quality, (2) higher processing throughput rate, and (3) lower S/W development cost. The image quality achieved by this algorithm is better than that previously achieved by the backprojection algorithm. The fine image quality is demonstrated by the SIR-C spotlight SAR images. 

    @InProceedings{Jin97:LightSAR,
Title = {{High Quality Spotlight SAR Processing Algorithm Designed for LightSAR Mission}},
Author = {Michael Y. Jin},
Booktitle = {IGARSS '97, International Geoscience and Remote Sensing Symposium},
Month = aug,
Pages = {477-480},
Volume = {29},
Year = {1997},
Abstract = {A high quality spotlight SAR processing algorithm is presented. In this algorithm, subband images of the radar illuminated spot are processed using well known strip mode processing algorithms. A full resolution image is then formed by (1) merging the spectra of subband images into a full band spectrum, and (2) taking an inverse FFT. Advantages of this algorithm include (1) higher image quality, (2) higher processing throughput rate, and (3) lower S/W development cost. The image quality achieved by this algorithm is better than that previously achieved by the backprojection algorithm. The fine image quality is demonstrated by the SIR-C spotlight SAR images.},
Keywords = {SAR Processing, Subband Images, LightSAR, SIR-C, Spotlight SAR},
Pdf = {../../../docs/jin97.pdf} 
}


  9. Chan Hian Lim and Yeo Tat Soon. Non-iterative spotlight SAR autofocusing using a modified phase-gradient approach. In Geoscience and Remote Sensing, 1997. IGARSS '97. 'Remote Sensing - A Scientific Vision for Sustainable Development'., 1997 IEEE International, volume 1, pages 484-486, August 1997. Keyword(s): SAR Processing, Autofocus, Phase Gradient Autofocus. 
    @InProceedings{Lim1997,
Title = {Non-iterative spotlight SAR autofocusing using a modified phase-gradient approach},
Author = {Chan Hian Lim and Yeo Tat Soon},
Booktitle = {Geoscience and Remote Sensing, 1997. IGARSS '97. 'Remote Sensing - A Scientific Vision for Sustainable Development'., 1997 IEEE International},
Doi = {10.1109/IGARSS.1997.615922},
Month = aug,
Pages = {484--486},
Volume = {1},
Year = {1997},
Keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus},
Owner = {ofrey} 
}


  10. P. Lombardo and F. Lombardini. Multi-baseline SAR interferometry for terrain slope adaptivity. In Radar Conference, 1997., IEEE National, pages 196-201, May 1997. 
    @InProceedings{Lombardo1997,
Title = {Multi-baseline SAR interferometry for terrain slope adaptivity},
Author = {Lombardo, P. and Lombardini, F.},
Booktitle = {Radar Conference, 1997., IEEE National},
Doi = {10.1109/NRC.1997.588303},
Month = may,
Pages = {196-201},
Year = {1997},
Owner = {ofrey} 
}


  11. S. Lawrence Marple, Jr.. Computing the discrete-time analytic signal via FFT. In Signals, Systems and Computers, 1997. Conference Record of the Thirty-First Asilomar Conference on, volume 2, pages 1322-1325, 1997. Keyword(s): Analytic Signal, discrete time systems, fast Fourier transforms, frequency-domain analysis, signal sampling, FFT, complex-valued decimated N/2-point discrete-time analytic signal, complex-valued interpolated NM-point discrete-time analyticsignal, complex-valued standard N-point discrete time analytic signal, discrete-time analytic signal, frequency-domain algorithms, real-valued N-point discrete-time signal, sample rate, transform end points, Hilbert Transform.
    Abstract: Starting with a real-valued N-point discrete-time signal,frequency-domain algorithms are provided for computing (1) thecomplex-valued standard N-point discrete time `analytic' signal of thesame sample rate, (2) the complex-valued decimated N/2-pointdiscrete-time analytic signal of half the original sample rate, and(3) the complex-valued interpolated NM-point discrete-time `analytic'signal of M times the original sample rate. Special adjustment oftransform end points is shown to generate proper discrete-time`analytic' signals 

    @InProceedings{marple97:AnalyticSignal,
Title = {Computing the discrete-time analytic signal via FFT},
Author = {{Marple, Jr.}, S. Lawrence},
Booktitle = {Signals, Systems and Computers, 1997. Conference Record of the Thirty-First Asilomar Conference on},
Pages = {1322--1325},
Url = {http://ieeexplore.ieee.org/iel4/5559/14886/00679118.pdf},
Volume = {2},
Year = {1997},
Abstract = {Starting with a real-valued N-point discrete-time signal,frequency-domain algorithms are provided for computing (1) thecomplex-valued standard N-point discrete time `analytic' signal of thesame sample rate, (2) the complex-valued decimated N/2-pointdiscrete-time analytic signal of half the original sample rate, and(3) the complex-valued interpolated NM-point discrete-time `analytic'signal of M times the original sample rate. Special adjustment oftransform end points is shown to generate proper discrete-time`analytic' signals},
Keywords = {Analytic Signal, discrete time systems, fast Fourier transforms, frequency-domain analysis, signal sampling, FFT, complex-valued decimated N/2-point discrete-time analytic signal, complex-valued interpolated NM-point discrete-time analyticsignal, complex-valued standard N-point discrete time analytic signal, discrete-time analytic signal, frequency-domain algorithms, real-valued N-point discrete-time signal, sample rate, transform end points, Hilbert Transform},
Owner = {ofrey},
Pdf = {../../../docs/marple97.pdf} 
}


  12. H. Rudolf, D. Tarchi, and A.J. Sieber. Combination of linear and circular SAR for 3-D features. In Geoscience and Remote Sensing, 1997. IGARSS '97. 'Remote Sensing - A Scientific Vision for Sustainable Development'., 1997 IEEE International, volume 4, pages 1551-1553, 1997. Keyword(s): SAR Processing, SAR Tomography, Tomography, geophysical techniques, radar imaging, remote sensing by radar, synthetic aperture radar, InSAR, LISA, buried object detection, circular SAR, circular aperture, geophysical measurement technique, ground penetrating radar, interferometric SAR, land surface, linear SAR, linear SAR outdoor system, mine detection, radar remote sensing, terrain mapping, three dimensional feature, vegetation mapping.
    Abstract: An economic and fast change of an existing radar system with alinear synthetic aperture into a system with 3D capabilities ispresented. For actual and future fields of radar in remote sensing, suchas high precision mine detection, highly accurate vegetationmeasurements and interferometric SAR applications the importance ofresolution in the third dimension is growing fast. Until now a such aradar required an expensive phased array antenna, a costly narrow-beamscanning system, or a combination of both of them. In order to overcomethese problems, the combination of an existing linear SAR outdoor system(LISA) with a circular aperture for vertical resolution led to a fastand economic additional 3rd dimension feature. A test experiment hasbeen performed to validate the system and the implemented SAR processor.The very promising results are presented. 

    @InProceedings{rudolfTarchiSieber97:Tomography,
author = {Rudolf, H. and Tarchi, D. and Sieber, A.J.},
booktitle = {Geoscience and Remote Sensing, 1997. IGARSS '97. 'Remote Sensing - A Scientific Vision for Sustainable Development'., 1997 IEEE International},
title = {Combination of linear and circular SAR for 3-D features},
year = {1997},
pages = {1551--1553},
volume = {4},
abstract = {An economic and fast change of an existing radar system with alinear synthetic aperture into a system with 3D capabilities ispresented. For actual and future fields of radar in remote sensing, suchas high precision mine detection, highly accurate vegetationmeasurements and interferometric SAR applications the importance ofresolution in the third dimension is growing fast. Until now a such aradar required an expensive phased array antenna, a costly narrow-beamscanning system, or a combination of both of them. In order to overcomethese problems, the combination of an existing linear SAR outdoor system(LISA) with a circular aperture for vertical resolution led to a fastand economic additional 3rd dimension feature. A test experiment hasbeen performed to validate the system and the implemented SAR processor.The very promising results are presented.},
keywords = {SAR Processing, SAR Tomography, Tomography, geophysical techniques, radar imaging, remote sensing by radar, synthetic aperture radar, InSAR, LISA, buried object detection, circular SAR, circular aperture, geophysical measurement technique, ground penetrating radar, interferometric SAR, land surface, linear SAR, linear SAR outdoor system, mine detection, radar remote sensing, terrain mapping, three dimensional feature, vegetation mapping},
owner = {ofrey},
pdf = {../../../docs/rudolfTarchiSieber97.pdf},
url = {http://ieeexplore.ieee.org/iel3/4810/13305/00608939.pdf},

}


  13. Shunhua Wang and Xiaotao Huang. Autofocus techniques for reducing phase errors in UWB-SAR. In IEEE National Aerospace and Electronics Conference, NAECON 1997, volume 2, pages 1009-1014, July 1997. Keyword(s): SAR Processing, Autofocus, Phase Gradient Autofocus, PGA, Residual Motion Errors, UWB SAR. 
    @InProceedings{wangHuang1997:Autofocus,
Title = {Autofocus techniques for reducing phase errors in UWB-SAR},
Author = {Shunhua Wang and Xiaotao Huang},
Booktitle = {IEEE National Aerospace and Electronics Conference, NAECON 1997},
Doi = {10.1109/NAECON.1997.622768},
Month = {jul},
Pages = {1009--1014},
Url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=622768&isnumber=13493},
Volume = {2},
Year = {1997},
Keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus, PGA, Residual Motion Errors, UWB SAR},
Owner = {ofrey},
Pdf = {../../../docs/wangHuang1997.pdf} 
}


  14. Weidong Yu and Zhaoda Zhu. Comparison of Doppler Centroid Estimation Methods in SAR. In IEEE National Aerospace and Electronics Conference NAECON, volume 2, pages 1015-1018, 1997. Keyword(s): SAR Processing, Doppler Centroid Estimation, Energy Balancing, Matched Correlation Estimator, Maximum Likelyhood Estimator, Sign Doppler Estimator, SDE, Correlation Doppler Estimator, CDE, ERS.
    Abstract: This paper compares five Doppler centroid estimation methods which are: energy balancing, matched-correlation maximum likelihood, correlation Doppler estimator (CDE) and sign Doppler estimator (SDE). Their estimation performances in raw data domain and image domain are studied. The computer simulation results are presented. ERS-1 raw data are also used to test the performances of every method. 

    @InProceedings{yuZhu97:DopCen,
Title = {{Comparison of Doppler Centroid Estimation Methods in SAR}},
Author = {Weidong Yu and Zhaoda Zhu},
Booktitle = {IEEE National Aerospace and Electronics Conference NAECON},
Pages = {1015--1018},
Url = {http://ieeexplore.ieee.org/iel3/4871/13493/00622769.pdf},
Volume = {2},
Year = {1997},
Abstract = {This paper compares five Doppler centroid estimation methods which are: energy balancing, matched-correlation maximum likelihood, correlation Doppler estimator (CDE) and sign Doppler estimator (SDE). Their estimation performances in raw data domain and image domain are studied. The computer simulation results are presented. ERS-1 raw data are also used to test the performances of every method.},
Keywords = {SAR Processing, Doppler Centroid Estimation, Energy Balancing, Matched Correlation Estimator, Maximum Likelyhood Estimator, Sign Doppler Estimator, SDE, Correlation Doppler Estimator, CDE, ERS},
Owner = {ofrey},
Pdf = {../../../docs/yuZhu97.pdf} 
}


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This collection of SAR literature is far from being complete.
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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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