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BACK TO INDEX Publications of year 1994 Books and proceedings
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| Abstract: | Deals with the simulation of synthetic aperture radar (SAR) raw signal of actual ground sites described in terms of sparse input data. Since in most cases the input data reference system does not match SAR requirements, it is necessary to adopt appropriate interpolation schemes. The authors focus their attention on elevation input data, noting that natural surfaces exhibit fractal properties. Fractal and nonfractal interpolation schemes are discussed and applied. Simulated images are shown and compared to actual examples. Subjective and objective tests validate the simulation and support the fractal-based elevation interpolation. |
@ARTICLE{francescMigliaRiccio94:Simulation,
author = {Giorgio Franceschetti and Maurizio Migliaccio and Daniele Riccio},
title = {{SAR Raw Signal Simulation of Actual Ground Sites Described in Terms of Sparse Input Data}},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
year = {1994},
volume = {32},
pages = {1160-1169},
number = {6},
month = Nov,
abstract = {Deals with the simulation of synthetic aperture radar (SAR) raw signal of actual ground sites described in terms of sparse input data. Since in most cases the input data reference system does not match SAR requirements, it is necessary to adopt appropriate interpolation schemes. The authors focus their attention on elevation input data, noting that natural surfaces exhibit fractal properties. Fractal and nonfractal interpolation schemes are discussed and applied. Simulated images are shown and compared to actual examples. Subjective and objective tests validate the simulation and support the fractal-based elevation interpolation.},
keywords = {SAR Processing, Simulation, SAR Simulator, Raw Data Simulator, Fractals, Sparse Input Data, SARAS},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/francescMigliaRiccio94.pdf},
url = {http://ieeexplore.ieee.org/iel1/36/7937/00338364.pdf}
}
Keywords: SAR Processing, SAR Interferometry, Interferometry, InSAR, Range Spectral Filter, geophysical techniques, remote sensing by radar, synthetic aperture radar, TINSAR, decorrelation reduction, Baseline Decorrelation, geophysical measurement technique, ground wavenumber spectra, land surface, local slope, low noise interferogram, off-nadir angle, phase unwrapping, quick-look interferogram, radar imaging, range resolution enhancement, relative shift, remote sensing, spectral shift, terrain mapping, wavenumber shift.
| Abstract: | SAR surveys from separate passes show relative shifts of the ground wavenumber spectra that depend on the local slope and the off-nadir angle. The authors discuss the exploitation of this spectral shift for different applications: 1) generation of \u201clow noise\u201d interferograms benefiting phase unwrapping, 2) generation of quick-look interferograms, 3) decorrelation reduction by means of tunable SAR systems (TINSAR), 4) range resolution enhancement, and 5) the combination of SAR data gathered by different platforms (airborne and satellite) for a \u201clong-time coherence\u201d study |
@ARTICLE{gatelliMontiGuarnieriParizziPasqualiPratiRocca1994:InSARWavenumberShift,
author = {Gatelli, Fabio and Monti-Guarnieri, Andrea and Parizzi, Francesco and Pasquali, Paolo and Prati, Claudio and Rocca, Fabio},
title = {{The wavenumber shift in SAR interferometry}},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
year = {1994},
volume = {32},
pages = {855--865},
number = {4},
month = {jul},
abstract = {SAR surveys from separate passes show relative shifts of the ground wavenumber spectra that depend on the local slope and the off-nadir angle. The authors discuss the exploitation of this spectral shift for different applications: 1) generation of \u201clow noise\u201d interferograms benefiting phase unwrapping, 2) generation of quick-look interferograms, 3) decorrelation reduction by means of tunable SAR systems (TINSAR), 4) range resolution enhancement, and 5) the combination of SAR data gathered by different platforms (airborne and satellite) for a \u201clong-time coherence\u201d study},
doi = {10.1109/36.298013},
issn = {0196-2892},
keywords = {SAR Processing, SAR Interferometry, Interferometry, InSAR, Range Spectral Filter, geophysical techniques, remote sensing by radar, synthetic aperture radar, TINSAR, decorrelation reduction, Baseline Decorrelation, geophysical measurement technique, ground wavenumber spectra, land surface, local slope, low noise interferogram, off-nadir angle, phase unwrapping, quick-look interferogram, radar imaging, range resolution enhancement, relative shift, remote sensing, spectral shift, terrain mapping, wavenumber shift},
owner = {ofrey},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/gatelliMontiGuarnieriParizziPasqualiPratiRocca1994.pdf},
url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=298013&isnumber=7386}
}
Keywords: SAR Processing, InSAR, Interferometry, SAR Interferometry, Phase Statistics, Decorrelation, Aberrations, Wavenumber Shift, Coregistration.
| Abstract: | Interferometric methods are well established in optics and radio astronomy. In recent years, interferometric concepts have been applied successfully to synthetic aperture radar (SAR) and have opened up new possibilities in the area of earth remote sensing. However interferometric SAR applications require thorough phase control through the imaging process. The phase accuracy of SAR images is affected by decorrelation effects between the individual surveys. We analyze quantitatively the influence of decorrelation on the phase statistics of SAR interferograms. In particular, phase aberrations as they occur in typical SAR processors are studied in detail. The dependence of the resulting phase bias and variance on processor parameters is presented in several diagrams. |
@ARTICLE{justBamler94:Phase,
author = {Dieter Just and Richard Bamler},
title = {{Phase Statistics of Interferograms with Applications to Synthetic Aperture Radar}},
journal = {Applied Optics},
year = {1994},
volume = {33},
pages = {4361-4368},
number = {20},
month = {jul},
abstract = {Interferometric methods are well established in optics and radio astronomy. In recent years, interferometric concepts have been applied successfully to synthetic aperture radar (SAR) and have opened up new possibilities in the area of earth remote sensing. However interferometric SAR applications require thorough phase control through the imaging process. The phase accuracy of SAR images is affected by decorrelation effects between the individual surveys. We analyze quantitatively the influence of decorrelation on the phase statistics of SAR interferograms. In particular, phase aberrations as they occur in typical SAR processors are studied in detail. The dependence of the resulting phase bias and variance on processor parameters is presented in several diagrams.},
keywords = {SAR Processing, InSAR, Interferometry, SAR Interferometry, Phase Statistics, Decorrelation, Aberrations, Wavenumber Shift, Coregistration},
owner = {ofrey},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/justBamler94.pdf},
url = {http://www.opticsinfobase.org/viewmedia.cfm?uri=ao-33-20-4361&seq=0}
}
Keywords: SAR Processing, Presumming, geophysical techniques, geophysics computing, image processing, remote sensing, remote sensing by radar, synthetic aperture radar, CNES general-purpose SAR correlator, constant phase reference, contrast seeker, data presumming, fast Fourier transform, frequency azimuth frequency domain, geophysical measurement technique, interferometry, land surface, migration compensation, multilooking, polynomial law generator, quick look, radar remote sensing, radiometric equalization map, signal processing, software, standard single look complex product, synthetic aperture radar, terrain mapping.
| Abstract: | CNES has designed a new SAR correlator to process both airborne |
@ARTICLE{massonnetAdragnaRossi94:Presumming,
author = {Massonnet, D. and Adragna, F. and Rossi, M.},
title = {CNES general-purpose SAR correlator},
journal = {Geoscience and Remote Sensing, IEEE Transactions on},
year = {1994},
volume = {32},
pages = {636--643},
number = {3},
abstract = {CNES has designed a new SAR correlator to process both airborne},
keywords = {SAR Processing, Presumming, geophysical techniques, geophysics computing, image processing, remote sensing, remote sensing by radar, synthetic aperture radar, CNES general-purpose SAR correlator, constant phase reference, contrast seeker, data presumming, fast Fourier transform, frequency azimuth frequency domain, geophysical measurement technique, interferometry, land surface, migration compensation, multilooking, polynomial law generator, quick look, radar remote sensing, radiometric equalization map, signal processing, software, standard single look complex product, synthetic aperture radar, terrain mapping},
owner = {ofrey},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/massonnetAdragnaRossi94.pdf},
url = {http://ieeexplore.ieee.org/iel1/36/7385/00297981.pdf}
}
Keywords: SAR Processing, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, Motion Compensation, Motion Estimation, Squinted SAR, Cubic Phase Term, Airborne SAR, Automatic Azimuth Coregistration, Azimuth Scaling, Squinted SAR, Interferometry, Phase-Preserving Processing, Range Scaling Formulation, Stripmap SAR, Subaperture Processing, Terrain Mapping.
| Abstract: | Proposes a new approach for high-resolution airborne SAR data processing, which uses a modified chirp scaling algorithm to accommodate the correction of motion errors, as well as the variations of the Doppler centroid in range and azimuth. By introducing a cubic phase term in the chirp scaling phase, data acquired with a squint angle up to 30? can be processed with no degradation of the impulse response function. The proposed approach is computationally very efficient, since it accommodates the variations of Doppler centroid without using block processing. Furthermore, a motion error extraction algorithm can be incorporated into the proposed approach by means of subaperture processing in azimuth. The new approach, denoted as extended chirp scaling, is considered to be a generalized algorithm suitable for the high-resolution processing of most airborne SAR systems. |
@ARTICLE{moreiraHuang94:ChirpScaling,
author = {Alberto Moreira and Yonghong Huang},
title = {{Airborne SAR Processing of Highly Squinted Data Using a Chirp Scaling Approach with Integrated Motion Compensation}},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
year = {1994},
volume = {32},
pages = {1029-1040},
number = {5},
month = Sept.,
abstract = {Proposes a new approach for high-resolution airborne SAR data processing, which uses a modified chirp scaling algorithm to accommodate the correction of motion errors, as well as the variations of the Doppler centroid in range and azimuth. By introducing a cubic phase term in the chirp scaling phase, data acquired with a squint angle up to 30? can be processed with no degradation of the impulse response function. The proposed approach is computationally very efficient, since it accommodates the variations of Doppler centroid without using block processing. Furthermore, a motion error extraction algorithm can be incorporated into the proposed approach by means of subaperture processing in azimuth. The new approach, denoted as extended chirp scaling, is considered to be a generalized algorithm suitable for the high-resolution processing of most airborne SAR systems.},
comment = {+ Paper discusses a variation of Chirp Scaling. See [RRB+94].},
keywords = {SAR Processing, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, Motion Compensation, Motion Estimation, Squinted SAR, Cubic Phase Term, Airborne SAR, Automatic Azimuth Coregistration, Azimuth Scaling, Squinted SAR, Interferometry, Phase-Preserving Processing, Range Scaling Formulation, Stripmap SAR, Subaperture Processing, Terrain Mapping},
owner = {ofrey},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/moreiraHuang94.pdf},
url = {http://ieeexplore.ieee.org/iel1/36/7578/00312891.pdf}
}
Keywords: SAR Processing, Chirp Scaling Algorithm, Range Migration Algorithm, omega-k, Wavenumber Domain Algorithm, Phase Preserving, Range-Doppler Algorithm, Comparison of Algorithms.
| Abstract: | A space-variant interpolation is required to compensate for the migration of signal energy through range resolution cells when processing synthetic aperture radar (SAR) data, using either the classical range/Doppler (R/D) algorithm or related frequency domain techniques. In general, interpolation requires significant computation time, and leads to loss of image quality, especially in the complex image. The new chirp scaling algorithm avoids interpolation, yet performs range cell migration correction accurately. The algorithm requires only complex multiplies and Fourier transforms to implement, is inherently phase preserving, and is suitable for wide-swath, large-beamwidth, and large-squint applications. This paper describes the chirp scaling algorithm, summarizes simulation results, presents imagery processed with the algorithm, and reviews quantitative measures of its performance. Based on quantitative comparison, the chirp scaling algorithm provides image quality equal to or better than the precision range/Doppler processor. Over the range of parameters tested, image quality results approach the theoretical limit, as defined by the system bandwidth. |
@ARTICLE{RaneyRunBamCummWong94:Precision,
author = {R. Keith Raney and Hartmut Runge and Richard Bamler and Ian G. Cumming and Frank Wong},
title = {{Precision SAR Processing Using Chirp Scaling}},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
year = {1994},
volume = {32},
pages = {786-799},
number = {4},
month = July,
abstract = {A space-variant interpolation is required to compensate for the migration of signal energy through range resolution cells when processing synthetic aperture radar (SAR) data, using either the classical range/Doppler (R/D) algorithm or related frequency domain techniques. In general, interpolation requires significant computation time, and leads to loss of image quality, especially in the complex image. The new chirp scaling algorithm avoids interpolation, yet performs range cell migration correction accurately. The algorithm requires only complex multiplies and Fourier transforms to implement, is inherently phase preserving, and is suitable for wide-swath, large-beamwidth, and large-squint applications. This paper describes the chirp scaling algorithm, summarizes simulation results, presents imagery processed with the algorithm, and reviews quantitative measures of its performance. Based on quantitative comparison, the chirp scaling algorithm provides image quality equal to or better than the precision range/Doppler processor. Over the range of parameters tested, image quality results approach the theoretical limit, as defined by the system bandwidth.},
comment = {++ Paper introduces the Chirp Scaling algorithm},
keywords = {SAR Processing, Chirp Scaling Algorithm, Range Migration Algorithm, omega-k, Wavenumber Domain Algorithm, Phase Preserving, Range-Doppler Algorithm, Comparison of Algorithms},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/RaneyRunBamCummWong94.pdf},
url = {http://ieeexplore.ieee.org/iel1/36/7386/00298008.pdf}
}
Keywords: Analytic Signal, Hilbert Transform, filtering theory, frequency estimation, parameter estimation, signal processing, signal synthesis, time-frequency analysis, Hilbert transform filters, analytic signal generation, discrete analytic signal, discrete real-valued signal, instantaneous-frequency estimation, modem designs, negative frequencies, positive frequencies, quadrature filters, time-frequency signal analysis.
| Abstract: | In this correspondence we discuss methods to produce the discreteanalytic signal from a discrete real-valued signal. Such an analyticsignal is complex and contains only positive frequencies. Its projectiononto the real axis is the same as the original signal. Our use stemsfrom instantaneous-frequency estimation and time-frequency signalanalysis problems. For these problems the negative frequency componentof real signals causes unwanted interference. The task of designing afilter to produce an approximation to the ideal analytic signal is notas simple as its formulation might suggest. Our result is that thedirect methods of zeroing the negative frequencies, or using Hilberttransform filters, have undesirable defects. We present an alternative which is similar to the quadrature filters used in modemdesigns |
@ARTICLE{reillyFrazerBoashash94:AnalyticSignal,
author = {Reilly, Andrew and Frazer, Gordon and Boashash, Boualem},
title = {Analytic Signal Generation-Tips and Traps},
journal = {Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on]},
year = {1994},
volume = {42},
pages = {3241--3245},
number = {11},
abstract = {In this correspondence we discuss methods to produce the discreteanalytic signal from a discrete real-valued signal. Such an analyticsignal is complex and contains only positive frequencies. Its projectiononto the real axis is the same as the original signal. Our use stemsfrom instantaneous-frequency estimation and time-frequency signalanalysis problems. For these problems the negative frequency componentof real signals causes unwanted interference. The task of designing afilter to produce an approximation to the ideal analytic signal is notas simple as its formulation might suggest. Our result is that thedirect methods of zeroing the negative frequencies, or using Hilberttransform filters, have undesirable defects. We present an alternative which is similar to the quadrature filters used in modemdesigns},
keywords = {Analytic Signal, Hilbert Transform, filtering theory, frequency estimation, parameter estimation, signal processing, signal synthesis, time-frequency analysis, Hilbert transform filters, analytic signal generation, discrete analytic signal, discrete real-valued signal, instantaneous-frequency estimation, modem designs, negative frequencies, positive frequencies, quadrature filters, time-frequency signal analysis},
owner = {ofrey},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/reillyFrazerBoashash94.pdf},
url = {http://ieeexplore.ieee.org/iel4/78/7823/00330385.pdf}
}
Keywords: SAR Processing, Autofocus, Phase Gradient Autofocus.
| Abstract: | The phase gradient autofocus (PGA) technique for phase error correction of spotlight mde synthetic aperture radar (SAR) imagery is examined carefully in the context of four fundamental signal processing steps that constitute the algorithm We demnstrate that excellent results over a wide variety of scene content, and phase error function structure are obtained if and only if all of these steps are included in the processing. Finally, we show that the computational demands of the full PGA algorithm do not represent a large fraction of the total image formation problem, when mid to large size images are involved. |
@ARTICLE{Wahl1994,
author = {Wahl, D.E. and Eichel, P.H. and Ghiglia, D.C. and Jakowatz, C.V.},
title = {{Phase gradient autofocus-a robust tool for high resolution SAR phase correction}},
journal = {IEEE Transactions on Aerospace and Electronic Systems},
year = {1994},
volume = {30},
pages = {827--835},
number = {3},
month = {July},
abstract = {The phase gradient autofocus (PGA) technique for phase
error correction of spotlight mde synthetic aperture radar
(SAR) imagery is examined carefully in the context of four
fundamental signal processing steps that constitute the algorithm
We demnstrate that excellent results over a wide variety of scene
content, and phase error function structure are obtained if and
only if all of these steps are included in the processing. Finally, we
show that the computational demands of the full PGA algorithm
do not represent a large fraction of the total image formation
problem, when mid to large size images are involved.},
keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus},
owner = {ofrey},
pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/wahlEichelGhigliaJakowatz94.pdf}
}
Conference articles
-
Matthew Braunstein,
James M. Ralston,
and David A. Sparrow.
Signal processing approaches to radio frequency interference (RFI) suppression.
In Dominick A. Giglio, editor,
Algorithms for Synthetic Aperture Radar Imagery,
volume 2230,
pages 190--208,
1994.
SPIE.
Keywords: SAR Processing, RFI Suppression, Ultra-Wideband SAR, Airborne SAR.Abstract: Ultra-wideband radar (UWB) has been shown to be among the most powerful techniques available for underground and obscured object detection. The value of such systems is that they combine the penetration enhancement associated with VHF/UHF (and lower) frequencies with the resolution of wide absolute bandwidth. Such systems necessarily make use of much of the frequency spectrum already in heavy use by other services, such as television and mobile communications. Although this spectral overlap provides occasion for adverse consequences in both directions, to date the principal consequence has been often-severe impact on UWB radar measurements. Even in remote locations, the average interference power often exceeds receiver noise by many dB, becoming the limiting factor on system sensitivity. Nor are UWB radar designers free to overcome this interference by increasing radar power, since regulatory sanction for UWB operation will depend on maintaining sufficiently low spectral power densities to assure that other, prior, services are not appreciably degraded. Given the importance of radio frequency interference (RFI) on practical ultrawide band ground penetrating radar systems, it is important to consider how and to what extent the effects of RFI noise may be reduced. The overall problem of RFI and its impacts will be described and several signal processing approaches to removal of RFI will be discussed. These include spectral estimation and coherent subtraction algorithms and various filter approaches, which have been developed and applied by the signal processing community in other contexts. These methods will be applied to several different real-world experimental data sets, and quantitative measures of the effectiveness of each of these algorithms in removing RFI noise will be presented. Although computationally-intensive, most of the techniques to be described achieve substantial increases in S/RFI without requiring concomitant increases in radar average power. @INPROCEEDINGS{braunsteinRalstonSparrow94:RFI, author = {Matthew Braunstein and James M. Ralston and David A. Sparrow}, title = {{Signal processing approaches to radio frequency interference (RFI) suppression}}, booktitle = {Algorithms for Synthetic Aperture Radar Imagery}, year = {1994}, editor = {Dominick A. Giglio}, volume = {2230}, number = {1}, pages = {190--208}, publisher = {SPIE}, abstract = {Ultra-wideband radar (UWB) has been shown to be among the most powerful techniques available for underground and obscured object detection. The value of such systems is that they combine the penetration enhancement associated with VHF/UHF (and lower) frequencies with the resolution of wide absolute bandwidth. Such systems necessarily make use of much of the frequency spectrum already in heavy use by other services, such as television and mobile communications. Although this spectral overlap provides occasion for adverse consequences in both directions, to date the principal consequence has been often-severe impact on UWB radar measurements. Even in remote locations, the average interference power often exceeds receiver noise by many dB, becoming the limiting factor on system sensitivity. Nor are UWB radar designers free to overcome this interference by increasing radar power, since regulatory sanction for UWB operation will depend on maintaining sufficiently low spectral power densities to assure that other, prior, services are not appreciably degraded. Given the importance of radio frequency interference (RFI) on practical ultrawide band ground penetrating radar systems, it is important to consider how and to what extent the effects of RFI noise may be reduced. The overall problem of RFI and its impacts will be described and several signal processing approaches to removal of RFI will be discussed. These include spectral estimation and coherent subtraction algorithms and various filter approaches, which have been developed and applied by the signal processing community in other contexts. These methods will be applied to several different real-world experimental data sets, and quantitative measures of the effectiveness of each of these algorithms in removing RFI noise will be presented. Although computationally-intensive, most of the techniques to be described achieve substantial increases in S/RFI without requiring concomitant increases in radar average power.}, keywords = {SAR Processing, RFI Suppression, Ultra-Wideband SAR, Airborne SAR}, location = {Orlando, FL, USA}, owner = {ofrey}, pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/braunsteinRalstonSparrow94.pdf}, url = {http://link.aip.org/link/?PSI/2230/190/1} } -
Charles V. Jakowatz,
Daniel E. Wahl,
Paul H. Eichel,
and Paul A. Thompson.
New formulation for interferometric synthetic aperture radar for terrain mapping.
In Dominick A. Giglio, editor,
,
volume 2230,
pages 411-418,
1994.
SPIE.
Keywords: SAR Processing, InSAR, SAR Interferometry, Terrain Mapping, Topography, Spotlight SAR, Spotlight-mode data.@conference{jakowatzWahlEichelThompsonInSAR1994, author = {Charles V. Jakowatz, Jr. and Daniel E. Wahl and Paul H. Eichel and Paul A. Thompson}, editor = {Dominick A. Giglio}, collaboration = {}, title = {New formulation for interferometric synthetic aperture radar for terrain mapping}, publisher = {SPIE}, year = {1994}, journal = {Algorithms for Synthetic Aperture Radar Imagery}, volume = {2230}, number = {1}, pages = {411-418}, location = {Orlando, FL, USA}, url = {http://link.aip.org/link/?PSI/2230/411/1}, doi = {10.1117/12.177193}, keywords = {SAR Processing, InSAR, SAR Interferometry, Terrain Mapping, Topography, Spotlight SAR, Spotlight-mode data}, pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/jakowatzWahlEichelThompsonInSAR1994.pdf}, owner = {ofrey}, } -
Alberto Moreira and Rolf Scheiber.
Doppler parameter estimation algorithms for SAR processing with the chirp scaling approach.
In Geoscience and Remote Sensing Symposium, 1994. IGARSS '94. 'Surface and Atmospheric Remote Sensing: Technologies, Data Analysis and Interpretation'., International,
volume 4,
pages 1977--1979,
1994.
Keywords: SAR Processing, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, SDE, CDE, Sign Doppler Estimator, Correlation Doppler Estimator, Doppler radar, FM radar, airborne radar, geophysical signal processing, geophysical techniques, radar applications, radar imaging, remote sensing by radar, spaceborne radar, synthetic aperture radar, Doppler parameter estimation algorithm, Doppler parameters, Doppler rate, SAC, SAR imaging, SAR processing, SPECAN, airborne radar, autocorrelation function, Chirp Scaling Algorithm, chirp scaling approach, correlation method, geophysical measurement technique, image processing, land surface, range-frequency centroid, remote sensing, shift and correlate algorithm, signal processing, spaceborne SAR, synthetic aperture radar, terrain mapping.Abstract: This paper presents several correlation based methods for estimation of the Doppler parameters from SAR raw data in connection with the chirp scaling algorithm. For the estimation of the Doppler rate, a modified approach of the shift and correlate (SAC) algorithm is proposed. In this case, the auto-correlation function of each data set and the standard deviation of the velocity calculations are used in order to monitor the validity of the estimations. For resolving the PRF ambiguity, a new approach is proposed, which is based on the estimation of the range-frequency centroid as a function of the azimuth frequency. Several results of the Doppler parameters estimation are presented for airborne and spaceborne SAR data @INPROCEEDINGS{moreiraScheiber94:DopplerParam, author = {Moreira, Alberto and Scheiber, Rolf}, title = {Doppler parameter estimation algorithms for SAR processing with the chirp scaling approach}, booktitle = {Geoscience and Remote Sensing Symposium, 1994. IGARSS '94. 'Surface and Atmospheric Remote Sensing: Technologies, Data Analysis and Interpretation'., International}, year = {1994}, volume = {4}, pages = {1977--1979}, abstract = {This paper presents several correlation based methods for estimation of the Doppler parameters from SAR raw data in connection with the chirp scaling algorithm. For the estimation of the Doppler rate, a modified approach of the shift and correlate (SAC) algorithm is proposed. In this case, the auto-correlation function of each data set and the standard deviation of the velocity calculations are used in order to monitor the validity of the estimations. For resolving the PRF ambiguity, a new approach is proposed, which is based on the estimation of the range-frequency centroid as a function of the azimuth frequency. Several results of the Doppler parameters estimation are presented for airborne and spaceborne SAR data}, keywords = {SAR Processing, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, SDE, CDE, Sign Doppler Estimator, Correlation Doppler Estimator, Doppler radar, FM radar, airborne radar, geophysical signal processing, geophysical techniques, radar applications, radar imaging, remote sensing by radar, spaceborne radar, synthetic aperture radar, Doppler parameter estimation algorithm, Doppler parameters, Doppler rate, SAC, SAR imaging, SAR processing, SPECAN, airborne radar, autocorrelation function, Chirp Scaling Algorithm, chirp scaling approach, correlation method, geophysical measurement technique, image processing, land surface, range-frequency centroid, remote sensing, shift and correlate algorithm, signal processing, spaceborne SAR, synthetic aperture radar, terrain mapping}, owner = {ofrey}, pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/moreiraScheiber94.pdf}, url = {http://ieeexplore.ieee.org/iel2/3183/9018/00399628.pdf} } -
Rolf Scheiber and Alberto Moreira.
Extension of the Correlation Doppler Estimator for Determination of the Doppler Rate and for Resolving the PRF-Ambiguity.
In Giorgio Franceschetti, editor,
SAR Data Processing for Remote Sensing,
volume SPIE # 2316,
pages 33-41,
1994.
Keywords: SAR Processing, Doppler Centroid, Doppler Centroid Estimation, Clutterlock, Correlation Doppler Estimator, CDE, Sign Doppler Estimator, SDE, Doppler Ambiguity Resolver, DAR, Doppler Rate Estimation, Autofocus.Abstract: Recently the chirp scaling algorithm has been proposed for high quality SAR processing. The algorithm requires first a transformation of the range uncompressed SAR raw data into the range-Doppler domain, which does not permit conventional techniques for the estimation of the Doppler parameters to be introduced efficiently into the processing. This paper first reviews the so called 'correlation Doppler estimator' (CDE), which was proposed for the estimation of the Doppler centroid in the time domain. This estimation algorithm is further extended in order to allow also the estimation of the Doppler rate. To perform this only bright targets are considered. By continuous calculation of the first coefficient of the auto-correlation function, the slope of the frequency history of the Doppler signal is determined, giving an exact estimate of the Doppler rate. to obtain also an estimation of the Doppler rate for scenes without bright targets but with some contrast, a modified version of the SAC algorithm is presented. Further a new method is presented, which can solve the PRF-ambiguity by means of an evaluation of the signal envelope skew in the range-Doppler domain. This technique does not require any additional range FFT, since it is based on the estimation of the variation of a range centroid as a function of the azimuth frequency. Several results are presented, which show the performance of the proposed new approaches. Some remarks are made regarding the inclusion of the described methods into the extended chirp scaling algorithm. @INPROCEEDINGS{scheiberMoreira94:DopCentrEst, author = {Rolf Scheiber and Alberto Moreira}, title = {{Extension of the Correlation Doppler Estimator for Determination of the Doppler Rate and for Resolving the PRF-Ambiguity}}, booktitle = {SAR Data Processing for Remote Sensing}, year = {1994}, editor = {Giorgio Franceschetti}, volume = SPIE # {2316}, pages = {33-41}, abstract = {Recently the chirp scaling algorithm has been proposed for high quality SAR processing. The algorithm requires first a transformation of the range uncompressed SAR raw data into the range-Doppler domain, which does not permit conventional techniques for the estimation of the Doppler parameters to be introduced efficiently into the processing. This paper first reviews the so called 'correlation Doppler estimator' (CDE), which was proposed for the estimation of the Doppler centroid in the time domain. This estimation algorithm is further extended in order to allow also the estimation of the Doppler rate. To perform this only bright targets are considered. By continuous calculation of the first coefficient of the auto-correlation function, the slope of the frequency history of the Doppler signal is determined, giving an exact estimate of the Doppler rate. to obtain also an estimation of the Doppler rate for scenes without bright targets but with some contrast, a modified version of the SAC algorithm is presented. Further a new method is presented, which can solve the PRF-ambiguity by means of an evaluation of the signal envelope skew in the range-Doppler domain. This technique does not require any additional range FFT, since it is based on the estimation of the variation of a range centroid as a function of the azimuth frequency. Several results are presented, which show the performance of the proposed new approaches. Some remarks are made regarding the inclusion of the described methods into the extended chirp scaling algorithm.}, keywords = {SAR Processing, Doppler Centroid, Doppler Centroid Estimation, Clutterlock, Correlation Doppler Estimator, CDE, Sign Doppler Estimator, SDE, Doppler Ambiguity Resolver, DAR, Doppler Rate Estimation, Autofocus}, pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/scheiber94.pdf}, url = {http://spie.org/scripts/abstract.pl?bibcode=1994SPIE5.082781e-27023165.316882e-2705.089991e-2708.548661e-26933S&page=1&qs=spie} } -
D.E. Wahl,
C.V. Jakowatz,
and P.A. Thompson.
New approach to strip-map SAR autofocus.
In Digital Signal Processing Workshop, 1994., 1994 Sixth IEEE,
pages 53--56,
2-5 Oct. 1994.
Keywords: SAR Processing, Autofocus, Phase Curvature Autofocus, Phase Gradient Autofocus.Abstract: This paper demonstrates how certain concepts from the Phase Gradient Autofocus (PGA) algorithm for automated refocus of spotlight mode SAR imagery may be used to design a similar algorithm that applies to SAR imagery formed in the conventional strip-mapping mode. The algorithm derivation begins with the traditional view of strip-map image formation as convolution (compression) using a linear FM chirp sequence. The appropriate analogies and modifications to the spotlight mode case are used to describe a working algorithm for strip-map autofocus. @INPROCEEDINGS{wahlJakowatzThompson1994:PhaseCurvatureAutofocus, author = {Wahl, D.E. and Jakowatz, C.V. and Thompson, P.A.}, title = {New approach to strip-map SAR autofocus}, booktitle = {Digital Signal Processing Workshop, 1994., 1994 Sixth IEEE}, year = {1994}, pages = {53--56}, month = {2-5 Oct.}, abstract = {This paper demonstrates how certain concepts from the Phase Gradient Autofocus (PGA) algorithm for automated refocus of spotlight mode SAR imagery may be used to design a similar algorithm that applies to SAR imagery formed in the conventional strip-mapping mode. The algorithm derivation begins with the traditional view of strip-map image formation as convolution (compression) using a linear FM chirp sequence. The appropriate analogies and modifications to the spotlight mode case are used to describe a working algorithm for strip-map autofocus.}, keywords = {SAR Processing, Autofocus, Phase Curvature Autofocus, Phase Gradient Autofocus}, owner = {ofrey}, pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/wahlJakowatzThompson1994.pdf}, url = {http://ieeexplore.ieee.org/iel2/3037/8630/00379875.pdf} }
Internal reports
-
Kenneth Knaell.
Three-Dimensional SAR from Curvilinear Apertures.
Technical report,
Carerock Division, Naval Surface Warfare Center,
1994.
Keywords: SAR Processing, Non-Linear Flight Path, SAR Tomography, 3D Feature Extraction, Target Feature Extraction, Curvilinear SAR.@TECHREPORT{knaellReport1994:NonLinearSARTomo, author = {Knaell, Kenneth}, title = {Three-Dimensional SAR from Curvilinear Apertures}, institution = {Carerock Division, Naval Surface Warfare Center}, year = {1994}, keywords = {SAR Processing, Non-Linear Flight Path, SAR Tomography, 3D Feature Extraction, Target Feature Extraction, Curvilinear SAR}, owner = {ofrey}, pdf = {http://www.geo.uzh.ch/~ofrey/protected/PAPERS/knaellReport1994.pdf}, timestamp = {2007.11.06} }
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This collection of SAR literature is far from being complete.
It is rather a collection of papers which I store in my literature data base. Hence, the list of publications under PUBLICATIONS OF AUTHOR'S NAME
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Last modified: Wed Sep 8 19:32:46 2010
Author: Othmar Frey , Remote Sensing Laboratories (RSL), University of Zurich, Switzerland .
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