Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316407
A. E. Nordsjo
An extended Kalman filter, EKF, is proposed for tracking the position and velocity of a moving target. The suggested method is based on a nonlinear model which, in addition, incorporates means for estimating possible nonlinearities in the measurements of the target position. In many practical scenarios, the initial estimates of target position and velocity deviate significantly from the true ones. In order to reduce the impact of erroneous initial conditions and, hence, obtain a faster initial convergence to an acceptable trajectory, a certain constrained form of the EKF, named the CEKF, is introduced. Although the original Kalman filter for a purely linear system is inherently stable, there is no guarantee that the linearized model used in the EKF gives a stable algorithm. Hence, it is interesting to note that the proposed CEKF under certain mild conditions renders an exponentially stable algorithm. It is shown that this latter method can conveniently be formulated as a nonlinear minimization problem with a quadratic inequality constraint.
{"title":"A constrained extended Kalman filter for target tracking","authors":"A. E. Nordsjo","doi":"10.1109/NRC.2004.1316407","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316407","url":null,"abstract":"An extended Kalman filter, EKF, is proposed for tracking the position and velocity of a moving target. The suggested method is based on a nonlinear model which, in addition, incorporates means for estimating possible nonlinearities in the measurements of the target position. In many practical scenarios, the initial estimates of target position and velocity deviate significantly from the true ones. In order to reduce the impact of erroneous initial conditions and, hence, obtain a faster initial convergence to an acceptable trajectory, a certain constrained form of the EKF, named the CEKF, is introduced. Although the original Kalman filter for a purely linear system is inherently stable, there is no guarantee that the linearized model used in the EKF gives a stable algorithm. Hence, it is interesting to note that the proposed CEKF under certain mild conditions renders an exponentially stable algorithm. It is shown that this latter method can conveniently be formulated as a nonlinear minimization problem with a quadratic inequality constraint.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"33 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116594811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316408
J. García, J. Besada, G. de Miguel, J. M. Molina, A. Berlanga
The paper analyses and evaluates the application of different techniques to the data association problem for ASDE (airport surface detection equipment) radar. Data association for this sensor requires the removal of the classical one-to-one constraints and should allow tracks to be updated by sets of blobs. Different innovative alternatives, based on recent advanced techniques, have been formulated and tried to solve this problem in complex scenarios. Simulation results show the capabilities achieved in terms of tracking robustness, accuracy and required computation.
{"title":"Analysis of advanced data association techniques for ASDE radar","authors":"J. García, J. Besada, G. de Miguel, J. M. Molina, A. Berlanga","doi":"10.1109/NRC.2004.1316408","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316408","url":null,"abstract":"The paper analyses and evaluates the application of different techniques to the data association problem for ASDE (airport surface detection equipment) radar. Data association for this sensor requires the removal of the classical one-to-one constraints and should allow tracks to be updated by sets of blobs. Different innovative alternatives, based on recent advanced techniques, have been formulated and tried to solve this problem in complex scenarios. Simulation results show the capabilities achieved in terms of tracking robustness, accuracy and required computation.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125419901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316500
H. Meng, Xiqin Wang, Hao Zhang, Yingning Peng
A method for evaluating the robustness of constant false alarm rate (CFAR) detectors is presented; it is based on the powerful methodology of influence function (IF) developed in the literature on robust statistics. The robustness of different kinds of CFAR detectors can be evaluated and compared by calculating the first derivative of the false alarm probability (FAP) and detection probability (DP) at an underlying distribution, which are named IF-FAP and IF-DP. The two IFs are compared among some kinds of CFAR detectors. It is concluded that the robustness of a detector can be asymptotically represented by the IF of the clutter power estimator. Finally, according to a robust measure drawn from the IF of the clutter power estimator, the "most robust" detectors in three ordered-statistic-based groups are presented.
{"title":"A method using influence function for evaluating robustness of CFAR detectors","authors":"H. Meng, Xiqin Wang, Hao Zhang, Yingning Peng","doi":"10.1109/NRC.2004.1316500","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316500","url":null,"abstract":"A method for evaluating the robustness of constant false alarm rate (CFAR) detectors is presented; it is based on the powerful methodology of influence function (IF) developed in the literature on robust statistics. The robustness of different kinds of CFAR detectors can be evaluated and compared by calculating the first derivative of the false alarm probability (FAP) and detection probability (DP) at an underlying distribution, which are named IF-FAP and IF-DP. The two IFs are compared among some kinds of CFAR detectors. It is concluded that the robustness of a detector can be asymptotically represented by the IF of the clutter power estimator. Finally, according to a robust measure drawn from the IF of the clutter power estimator, the \"most robust\" detectors in three ordered-statistic-based groups are presented.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116136303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316479
Xiaobo Hou, A. Daryoush, W. Rosen, H. Burstyn, P. Zalud
An all-optical analog-to-digital converter capable of sampling at 50 GS/s is described. The ADC works in the spectral domain, unlike the other all-optical or hybrid methods. The RF signal is sampled by electro-optically steerable gratings and quantized by a set of detectors with scalable apertures. Low timing jitter is provided by a mode-locked laser.
{"title":"Design of an ultra high-speed all-optical analog-to-digital converter","authors":"Xiaobo Hou, A. Daryoush, W. Rosen, H. Burstyn, P. Zalud","doi":"10.1109/NRC.2004.1316479","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316479","url":null,"abstract":"An all-optical analog-to-digital converter capable of sampling at 50 GS/s is described. The ADC works in the spectral domain, unlike the other all-optical or hybrid methods. The RF signal is sampled by electro-optically steerable gratings and quantized by a set of detectors with scalable apertures. Low timing jitter is provided by a mode-locked laser.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124299480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316499
M. Derakhtian, M. Nayebi, A. Tadaion
We propose a new detector to test the presence of a radar signal with unknown parameters in unknown variance additive white Gaussian noise. Uniformly most powerful invariant (UMPI) tests and unitary filter banks are combined in a new detector. This problem does not fit the linear model due to the unknown Doppler frequency. It is found that the UMPI test does not exist for such a problem. In our detector, we apply an appropriate linear transformation, which is a unitary filter bank, to the concerned radar signal and the problem is converted to the canonical form. Since the UMPI test does exist for the canonical form, then we derive an optimal invariant test for our problem.
{"title":"Optimal invariant test in coherent radar detection with unknown parameters","authors":"M. Derakhtian, M. Nayebi, A. Tadaion","doi":"10.1109/NRC.2004.1316499","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316499","url":null,"abstract":"We propose a new detector to test the presence of a radar signal with unknown parameters in unknown variance additive white Gaussian noise. Uniformly most powerful invariant (UMPI) tests and unitary filter banks are combined in a new detector. This problem does not fit the linear model due to the unknown Doppler frequency. It is found that the UMPI test does not exist for such a problem. In our detector, we apply an appropriate linear transformation, which is a unitary filter bank, to the concerned radar signal and the problem is converted to the canonical form. Since the UMPI test does exist for the canonical form, then we derive an optimal invariant test for our problem.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114474787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316427
Y. Zhang, A. Hajjari, L. Adzima, B. Himed
This paper discusses beam-domain space-time adaptive processing (STAP) algorithms for a low-Earth-orbit (LEO) space-based radar (SBR). The performance of the subarray-based joint-domain-localized (JDL) algorithm is first examined for various processor parameters. Then, a combined beam-domain STAP algorithm approach that combines JDL with difference (/spl Delta/) beams is presented. It is shown that the combined JDL-/spl Delta/ algorithms offer less system complexity and yield performance similar to that of JDL that uses higher degrees of freedom. It is also shown that the Earth's rotation induces a crab angle to the platform, which makes the clutter range-Doppler spectrum vary with range. Illustrative examples show that this crab angle severely degrades the signal-to-interference-plus-noise ratio (SINR), thereby reducing the minimum detectable velocity (MDV) of STAP systems.
{"title":"Adaptive beam-domain processing for space-based radars","authors":"Y. Zhang, A. Hajjari, L. Adzima, B. Himed","doi":"10.1109/NRC.2004.1316427","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316427","url":null,"abstract":"This paper discusses beam-domain space-time adaptive processing (STAP) algorithms for a low-Earth-orbit (LEO) space-based radar (SBR). The performance of the subarray-based joint-domain-localized (JDL) algorithm is first examined for various processor parameters. Then, a combined beam-domain STAP algorithm approach that combines JDL with difference (/spl Delta/) beams is presented. It is shown that the combined JDL-/spl Delta/ algorithms offer less system complexity and yield performance similar to that of JDL that uses higher degrees of freedom. It is also shown that the Earth's rotation induces a crab angle to the platform, which makes the clutter range-Doppler spectrum vary with range. Illustrative examples show that this crab angle severely degrades the signal-to-interference-plus-noise ratio (SINR), thereby reducing the minimum detectable velocity (MDV) of STAP systems.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124893113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316392
W. Carrara, R. Goodman, M.A. Ricoy
The widefield polar format algorithm, the Stolt polar algorithm, and the differential Doppler algorithm use variations of a new along-track alignment and formatting system (ATAFS) to generate fine-resolution images from synthetic aperture radar (SAR) data. ATAFS introduces a spatially variant modification of the SAR phase history storage format to remove the formatting inaccuracies of the conventional polar format algorithm and enables full image quality over large scenes without range curvature distortion or image defocus. These new algorithms are well-suited for processing fine resolution spotlight and ultra-wideband SAR data. Their image quality performance is comparable to that of the range migration algorithm (RMA). Unlike RMA, the new algorithms operate on data stabilized to a fixed reference point to remove the azimuth chirp (the Doppler bandwidth of the reference point) before it compromises processor efficiency.
{"title":"New algorithms for widefield SAR image formation","authors":"W. Carrara, R. Goodman, M.A. Ricoy","doi":"10.1109/NRC.2004.1316392","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316392","url":null,"abstract":"The widefield polar format algorithm, the Stolt polar algorithm, and the differential Doppler algorithm use variations of a new along-track alignment and formatting system (ATAFS) to generate fine-resolution images from synthetic aperture radar (SAR) data. ATAFS introduces a spatially variant modification of the SAR phase history storage format to remove the formatting inaccuracies of the conventional polar format algorithm and enables full image quality over large scenes without range curvature distortion or image defocus. These new algorithms are well-suited for processing fine resolution spotlight and ultra-wideband SAR data. Their image quality performance is comparable to that of the range migration algorithm (RMA). Unlike RMA, the new algorithms operate on data stabilized to a fixed reference point to remove the azimuth chirp (the Doppler bandwidth of the reference point) before it compromises processor efficiency.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130680667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316395
L. Nguyen, M. Ressler, David C. Wong, M. Soumekh
This paper examines signal processing methods for improving the fidelity of backprojection SAR imagery using a preprocessing method that suppresses Doppler aliasing as well as other side lobe artifacts that are introduced by the radar radiation pattern. The algorithm, known as digital spotlighting, imposes a filtering scheme on the azimuth-compressed SAR data, and manipulates the resultant spectral data to achieve a higher PRF to suppress the Doppler aliasing. The merits of the algorithm are studied using the ARL boom-SAR data.
{"title":"Enhancement of backprojection SAR imagery using digital spotlighting preprocessing","authors":"L. Nguyen, M. Ressler, David C. Wong, M. Soumekh","doi":"10.1109/NRC.2004.1316395","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316395","url":null,"abstract":"This paper examines signal processing methods for improving the fidelity of backprojection SAR imagery using a preprocessing method that suppresses Doppler aliasing as well as other side lobe artifacts that are introduced by the radar radiation pattern. The algorithm, known as digital spotlighting, imposes a filtering scheme on the azimuth-compressed SAR data, and manipulates the resultant spectral data to achieve a higher PRF to suppress the Doppler aliasing. The merits of the algorithm are studied using the ARL boom-SAR data.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123329266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316487
Y. Lin, Y. Peng, X. Wang
In this paper, a novel method for estimating the parameters of multiple chirp signals in additive Gaussian white noise is proposed. The method combines a global optimization theorem with a new Markov chain Monte Carlo algorithm, called the simulated annealing one-variable-at-a-time random walk Metropolis-Hastings algorithm. It is a computationally modest implementation of maximum likelihood estimation and has no error propagation effect. Simulation results show that the proposed method can give good estimates for the unknown parameters, even when the parameters of the individual chirp signals are closely spaced and the Cramer-Rao lower bound can be attained even at low signal-to-noise ratio.
{"title":"Maximum likelihood parameter estimation of multiple chirp signals by a new Markov chain Monte Carlo approach","authors":"Y. Lin, Y. Peng, X. Wang","doi":"10.1109/NRC.2004.1316487","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316487","url":null,"abstract":"In this paper, a novel method for estimating the parameters of multiple chirp signals in additive Gaussian white noise is proposed. The method combines a global optimization theorem with a new Markov chain Monte Carlo algorithm, called the simulated annealing one-variable-at-a-time random walk Metropolis-Hastings algorithm. It is a computationally modest implementation of maximum likelihood estimation and has no error propagation effect. Simulation results show that the proposed method can give good estimates for the unknown parameters, even when the parameters of the individual chirp signals are closely spaced and the Cramer-Rao lower bound can be attained even at low signal-to-noise ratio.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126883233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-26DOI: 10.1109/NRC.2004.1316388
C. Le, S. Chan, F. Cheng, W. Fang, M. Fischman, S. Hensley, R. Johnson, M. Jourdan, M. Marina, B. Parham, F. Rogez, P. Rosen, B. Shah, S. Taft
We present a real-time high-performance and fault-tolerant FPGA-based hardware architecture for the processing of synthetic aperture radar (SAR) images in future spaceborne systems. In particular, we discuss the integrated design approach, from top-level algorithm specifications and system requirements, design methodology, functional verification and performance validation, down to hardware design and implementation.
{"title":"Onboard FPGA-based SAR processing for future spaceborne systems","authors":"C. Le, S. Chan, F. Cheng, W. Fang, M. Fischman, S. Hensley, R. Johnson, M. Jourdan, M. Marina, B. Parham, F. Rogez, P. Rosen, B. Shah, S. Taft","doi":"10.1109/NRC.2004.1316388","DOIUrl":"https://doi.org/10.1109/NRC.2004.1316388","url":null,"abstract":"We present a real-time high-performance and fault-tolerant FPGA-based hardware architecture for the processing of synthetic aperture radar (SAR) images in future spaceborne systems. In particular, we discuss the integrated design approach, from top-level algorithm specifications and system requirements, design methodology, functional verification and performance validation, down to hardware design and implementation.","PeriodicalId":268965,"journal":{"name":"Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130469969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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