Study On The Techniques Of Interference Suppression In The Ultra-Wide Band Ground Penetrating SAR

Recent years, Ground Penetrating Synthetic Aperture Radar(GPSAR) has been well developed and been applied to many fields. As a short-range detection radar, it is influenced not only by the Radio Frequency Interference (RFI), but also by the coupling clutter. To improve the SAR images quality, we have to suppress the clutter effectively.The paper is based on the subject of clutter suppression of the Rail-GPSAR system which was build by National University of Defense Technology. Here it introduces many of traditional approaches to suppress the clutter. The paper pays much attention to these approaches: Adaptive Filtering, Eigen-subspace Decomposition Filtering and 2D Fourier Transform Filtering.Adaptive filtering can not only cancel the coupling clutter but also predict the RFI. The approach proved to be effective to restrain the complex clutter of Rail-GPSAR.Eigen-subspace decomposition filtering suppresses the clutter by projecting the received signal to the'signal-subspace'.'Signal-subspace'is obtained by eigenvector-subspace decomposition.2D Fourier transform filtering is a novel way to suppress the interference. It projects the received signals to the 2D Fourier Domain. The target echoes and the interference clutter are distributed to different areas. Then we can estimate the spectrum of RFI and restrain the clutter by a wiener filter.By analyzing the result, we found these three approaches can suppress the clutter effectively. The performance of each filter is satisfied.