Multi-Channel SAR-GMTI Method Robust to Coregistration Error of SAR Images

High accuracy in complex images coregistration is essential in ground moving target indication (GMTI) processing of synthetic aperture radar (SAR) data, normally termed SAR-GMTI. The clutter suppression performance is proportional to the coregistration accuracy. In this correspondence, we propose a new SAR-GMTI approach, which is robust to the SAR images coregistration error. The observed clutter-plus-noise vector is built using the neighboring pixels as the first step, thus the corresponding covariance matrix, termed as joint covariance matrix, can be estimated. The joint noise subspace is obtained by eigen-decomposing of the joint covariance matrix. The clutter is suppressed successfully by a projecting operation, i.e., a projection of the joint observed vector into the resulting joint noise subspace. The information of neighboring pixels is substantially exploited in the clutter suppression, resulting in the robustness, even at the presence of large coregistration error. Both the simulated and real multi-channel airborne data are used to validate the proposed approach.

[1]  Jean-Yves Chouinard,et al.  Metrics for SAR-GMTI based on eigen-decomposition of the sample covariance matrix , 2003, 2003 Proceedings of the International Conference on Radar (IEEE Cat. No.03EX695).

[2]  Mehrdad Soumekh.  Signal subspace fusion of uncalibrated sensors with application in SAR and diagnostic medicine , 1999, IEEE Trans. Image Process..

[3]  E. Chapin,et al.  GMTI along-track interferometry experiment , 2006, IEEE Aerospace and Electronic Systems Magazine.

[4]  F. Gini,et al.  Multibaseline ATI-SAR for robust ocean surface velocity estimation , 2001, IEEE Transactions on Aerospace and Electronic Systems.

[5]  Zheng Bao,et al.  Improving Coherence of Complex Image Pairs Obtained by Along-Track Bistatic SARs Using Range–Azimuth Prefiltering , 2008, IEEE Transactions on Geoscience and Remote Sensing.

[6]  L. E. Brennan,et al.  Adaptive arrays in airborne MTI radar , 1976 .

[7]  Richard M. Goldstein,et al.  Studies of multibaseline spaceborne interferometric synthetic aperture radars , 1990 .

[8]  R. Goldstein,et al.  Crossed orbit interferometry: theory and experimental results from SIR-B , 1988 .

[9]  R. P. Perry,et al.  SAR imaging of moving targets , 1999 .

[10]  João R. Moreira,et al.  A new MTI-SAR approach using the reflectivity displacement method , 1995, IEEE Trans. Geosci. Remote. Sens..

[11]  Didier Massonnet,et al.  Capabilities and limitations of the interferometric cartwheel , 2001, IEEE Trans. Geosci. Remote. Sens..

[12]  J.H.G. Ender.  Space-time processing for multichannel synthetic aperture radar , 1999 .

[13]  Zheng Bao,et al.  Image autocoregistration and InSAR interferogram estimation using joint subspace projection , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[14]  Richard G. Cobb,et al.  TechSat 21 - Space Missions using Collaborating Constellations of Satellites , 1998 .

[15]  Mehrdad Soumekh.  Moving Target Detection and Motion Estimation in Foliage Using along Track Monopulse Synthetic Aperture Radar Imaging and Signal Subspace Processing of Uncalibrated MTD-SARs. , 1997 .

[16]  Christoph H. Gierull,et al.  Raw data based two-aperture SAR ground moving target indication , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[17]  Kidiyo Kpalma,et al.  An automatic image registration for applications in remote sensing , 2005, IEEE Transactions on Geoscience and Remote Sensing.

[18]  Sergio Barbarossa,et al.  Space-time-frequency processing of synthetic aperture radar signals , 1994 .

[19]  Jan Flusser,et al.  Image registration methods: a survey , 2003, Image Vis. Comput..

[20]  A. Haimovich,et al.  The eigencanceler: adaptive radar by eigenanalysis methods , 1996, IEEE Transactions on Aerospace and Electronic Systems.

[21]  Roland Romeiser,et al.  Theoretical Evaluation of Several Possible Along-Track InSAR Modes of TerraSAR-X for Ocean Current Measurements , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[22]  H. Griffiths,et al.  Estimating ocean surface velocity and coherence time using multichannel ATI-SAR systems , 2000 .

[23]  Christoph H. Gierull,et al.  Statistical analysis of multilook SAR interferograms for CFAR detection of ground moving targets , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[24]  Wasfy B. Mikhael,et al.  Estimation of the clutter rank in the case of subarraying for space-time adaptive processing , 1997 .

[25]  Hong Wang,et al.  On adaptive spatial-temporal processing for airborne surveillance radar systems , 1994 .

[26]  Mehrdad Soumekh,et al.  Moving target detection in foliage using along track monopulse synthetic aperture radar imaging , 1997, IEEE Trans. Image Process..

[27]  R. Lipps,et al.  Advanced SAR GMTI techniques , 2004, Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509).

[28]  J. Fienup.  Detecting moving targets in SAR imagery by focusing , 2001 .

[29]  Delwyn Moller,et al.  Measurements of ocean surface waves and currents using L- and C-band along-track interferometric SAR , 2003, IEEE Trans. Geosci. Remote. Sens..

[30]  B. Friedlander,et al.  VSAR: a high resolution radar system for detection of moving targets , 1997 .

[31]  M. Pettersson,et al.  Detection of moving targets in wideband SAR , 2004, IEEE Transactions on Aerospace and Electronic Systems.

[32]  Richard Klemm,et al.  Adaptive clutter suppression for airborne phased array radars , 1983 .