A New SAR–GMTI High-Accuracy Focusing and Relocation Method Using Instantaneous Interferometry

In this paper, for a multichannel synthetic aperture radar-ground moving target indication (SAR-GMTI) system, a new high-accuracy focusing and relocating method using instantaneous interferometry, i.e., carrying out interferometry operation in the azimuth time domain before focusing, is proposed. One of the key steps of this method is to perform instantaneous interferometry to get accurate equivalent cross-track velocity (ECV) estimation for cross-track motion compensation. After that, the signal from a moving target is concentrated in range, and along-track motion compensation becomes convenient. Motion compensation transforms a moving target into a stationary one; thus, the conventional SAR imaging algorithm can be applied to focus the moving target. Finally, a strategy for accurately relocating a moving target is presented. The processing results of simulated and measured data illustrate the effectiveness of the proposed method.

[1]  Wu Shu-yue.  New Properties of the Radon Transform of the Cross Wigner/Ambiguity Distribution Function , 2001 .

[2]  Michael Jin.  Optimal Doppler Centroid Estimation for SAR Data from a Quasi-Homogeneous Source , 1986, IEEE Transactions on Geoscience and Remote Sensing.

[3]  John C. Wood,et al.  Linear signal synthesis using the Radon-Wigner transform , 1994, IEEE Trans. Signal Process..

[4]  LJubisa Stankovic,et al.  Robust Wigner distribution with application to the instantaneous frequency estimation , 2001, IEEE Trans. Signal Process..

[5]  Nicolas Gebert,et al.  Multi-Channel Azimuth Processing for High-Resolution Wide-Swath SAR Imaging , 2009 .

[6]  Christoph H. Gierull,et al.  The influence of target acceleration on velocity estimation in dual-channel SAR-GMTI , 2006, IEEE Transactions on Geoscience and Remote Sensing.

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

[8]  Mengdao Xing,et al.  Robust Ground Moving-Target Imaging Using Deramp–Keystone Processing , 2013, IEEE Transactions on Geoscience and Remote Sensing.

[9]  Richard Klemm,et al.  Introduction to space-time adaptive processing , 1998 .

[10]  Alexander D. Poularikas,et al.  Transforms and Applications Handbook, Third Edition , 2010 .

[11]  Mingjie Zheng,et al.  Channel balancing algorithm in multichannel wide-area surveillance systems , 2014 .

[12]  Zheng Bao,et al.  Effects of Doppler Aliasing on Baseline Estimation in Multichannel SAR-GMTI and Solutions to Address These Effects , 2014, IEEE Transactions on Geoscience and Remote Sensing.

[13]  Ishuwa C. Sikaneta,et al.  Adaptive CFAR for Space-Based Multichannel SAR–GMTI , 2012, IEEE Transactions on Geoscience and Remote Sensing.

[14]  Ran Tao,et al.  Short-Time Fractional Fourier Transform and Its Applications , 2010, IEEE Transactions on Signal Processing.

[15]  Guisheng Liao,et al.  Estimating Ambiguity-Free Motion Parameters of Ground Moving Targets From Dual-Channel SAR Sensors , 2014, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.

[16]  Ran Tao,et al.  Sampling and Sampling Rate Conversion of Band Limited Signals in the Fractional Fourier Transform Domain , 2008, IEEE Transactions on Signal Processing.

[17]  W. Clem Karl,et al.  Imaging of Moving Targets With Multi-Static SAR Using an Overcomplete Dictionary , 2009, IEEE Journal of Selected Topics in Signal Processing.

[18]  Mengdao Xing,et al.  Adaptive two-step calibration for high resolution and wide-swath SAR imaging , 2010 .

[19]  P. Marques,et al.  Velocity estimation of fast moving targets using a single SAR sensor , 2005, IEEE Transactions on Aerospace and Electronic Systems.

[20]  Sergio Barbarossa,et al.  Detection and imaging of moving objects with synthetic aperture radar. Part 2: Joint time-frequency analysis by Wigner-Ville distribution , 1992 .

[21]  H.S.C. Wang.  Mainlobe clutter cancellation by DPCA for space-based radars , 1991, 1991 IEEE Aerospace Applications Conference Digest.

[22]  Vito Pascazio,et al.  Moving target detection by along-track interferometry , 2001, IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217).

[23]  Sergio Barbarossa,et al.  Analysis of multicomponent LFM signals by a combined Wigner-Hough transform , 1995, IEEE Trans. Signal Process..

[24]  Vito Pascazio,et al.  Estimation of Radial Velocity of Moving Targets by Along-Track Interferometric SAR Systems , 2008, IEEE Geoscience and Remote Sensing Letters.

[25]  Wen-Qin Wang,et al.  Two-Antenna SAR With Waveform Diversity for Ground Moving Target Indication , 2014, IEEE Geoscience and Remote Sensing Letters.

[26]  Mengdao Xing,et al.  A Novel Moving Target Imaging Algorithm for HRWS SAR Based on Local Maximum-Likelihood Minimum Entropy , 2014, IEEE Transactions on Geoscience and Remote Sensing.

[27]  J.J. Vaccaro,et al.  Planar subarray processing for SAR imaging , 1995, Proceedings International Radar Conference.

[28]  Renbiao Wu,et al.  Approach for single channel SAR ground moving target imaging and motion parameter estimation , 2007 .

[29]  Luís B. Almeida,et al.  The fractional Fourier transform and time-frequency representations , 1994, IEEE Trans. Signal Process..

[30]  Boualem Boashash,et al.  Instantaneous frequency estimation of quadratic and cubic FM signals using the cross polynomial Wigner-Ville distribution , 1996, IEEE Trans. Signal Process..

[31]  Xiang-Gen Xia,et al.  Discrete chirp-Fourier transform and its application to chirp rate estimation , 2000, IEEE Trans. Signal Process..

[32]  Gang Li,et al.  Doppler Keystone Transform: An Approach Suitable for Parallel Implementation of SAR Moving Target Imaging , 2008, IEEE Geoscience and Remote Sensing Letters.

[33]  R.L. Fante,et al.  Space-based bistatic GMTI using low resolution SAR , 1997, 1997 IEEE Aerospace Conference.

[34]  Srdjan Stankovic,et al.  An analysis of instantaneous frequency representation using time-frequency distributions-generalized Wigner distribution , 1995, IEEE Trans. Signal Process..

[35]  James Ward,et al.  Space-time adaptive processing for airborne radar , 1998 .

[36]  Guisheng Liao,et al.  Ground Moving Targets Imaging Algorithm for Synthetic Aperture Radar , 2011, IEEE Transactions on Geoscience and Remote Sensing.