Clutter Suppression via Subspace Projection for Spaceborne HRWS Multichannel SAR System

Traditional clutter suppression methods are mainly studied under the condition that the pulse repetition frequency (PRF) of the system is not less than the Nyquist frequency. Whereas in the high-resolution and wide-swath (HRWS) multichannel synthetic aperture radar (SAR) system, a low PRF is used to break through the minimum antenna area constraint. The low PRF case brings new challenges to the traditional clutter suppression methods. In this letter, a subspace projection clutter suppression method is proposed based on the fact that moving targets and the clutter consist in different signal subspaces. This method can be directly applied to the HRWS multichannel SAR system, and it shows better performance compared to the space-time adaptive processing (STAP) when the moving target components cannot be ignored in the clutter covariance matrix calculation. Simulated data and airborne measured data are processed to verify its effectiveness.

[1]  Ning.  Channel Phase Mismatch Calibration for Multichannel in Azimuth SAR Imaging Based on Eigen-structure Method , 2018 .

[2]  Xian-Da Zhang,et al.  Matrix Analysis and Applications , 2017 .

[3]  Jie Li,et al.  Moving Target Detection via Efficient ATI-GoDec Approach for Multichannel SAR System , 2016, IEEE Geoscience and Remote Sensing Letters.

[4]  Hong Wang,et al.  Coherent signal-subspace processing for the detection and estimation of angles of arrival of multiple wide-band sources , 1985, IEEE Trans. Acoust. Speech Signal Process..

[5]  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.

[6]  Gerhard Krieger,et al.  Errata: Digital Beamforming on Receive: Techniques and Optimization Strategies for High-Resolution Wide-Swath SAR Imaging , 2009 .

[7]  Khaled Assaleh,et al.  Space-Time Adaptive Processing Using Pattern Classification , 2015, IEEE Transactions on Signal Processing.

[8]  Zheng Bao,et al.  Channel Error Estimation Methods for Multichannel SAR Systems in Azimuth , 2013, IEEE Geosci. Remote. Sens. Lett..

[9]  Zheng Bao,et al.  Generation of wide-swath and high-resolution SAR images from multichannel small spaceborne SAR systems , 2005, IEEE Geosci. Remote. Sens. Lett..

[10]  Zhihui Li,et al.  Training samples selection method for space-time adaptive processing based on clutter covariance matrix reconstruction , 2017 .

[11]  Gui Gao,et al.  Ship Detection in Dual-Channel ATI-SAR Based on the Notch Filter , 2017, IEEE Transactions on Geoscience and Remote Sensing.

[12]  Birsen Yazıcı,et al.  Doppler-DPCA and Doppler-ATI: Novel SAR Modalities for Imaging of Moving Targets Using Ultra-Narrowband Waveforms , 2018, IEEE Transactions on Computational Imaging.

[13]  Yi Liang,et al.  Deramp Space–Time Adaptive Processing for Multichannel SAR Systems , 2014, IEEE Geoscience and Remote Sensing Letters.

[14]  Gerhard Krieger,et al.  Digital Beamforming on Receive: Techniques and Optimization Strategies for High-Resolution Wide-Swath SAR Imaging , 2009, IEEE Transactions on Aerospace and Electronic Systems.

[15]  M. Morf,et al.  Estimation of time differences of arrival by pole decomposition , 1983 .

[16]  Chibiao Ding,et al.  Velocity estimation of moving targets for spaceborne multichannel synthetic aperture radar systems based on equivalent along-track interferometry technique , 2018 .

[17]  Mengdao Xing,et al.  Multichannel HRWS SAR Imaging Based on Range-Variant Channel Calibration and Multi-Doppler-Direction Restriction Ambiguity Suppression , 2014, IEEE Transactions on Geoscience and Remote Sensing.

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