Radio Frequency Interference Mitigation in SAR Systems via Multi-Polarization Framework

Synthetic aperture radar (SAR) is a type of active microwave remote sensing imaging radar that can generate 2-D high-resolution images. Its ability to operate in all weather conditions and at all times has led to its widespread use. As a multiparameter and multichannel extension of SAR, polarimetric SAR (PolSAR) provides a wealth of scattering information for various applications, including topographic mapping, ocean exploration, polar observation, and target identification. Compared with single-polarization SAR, multi-polarization SAR enhances the information potential of the data by expanding its 1-D information; however, this potential cannot be fully realized without a clean SAR echo signal. The electromagnetic environment is becoming increasingly congested with radio frequency interference (RFI) signals, presenting a significant challenge for the subsequent tasks of PolSAR. Although there have been many related studies based on polarization information to carry out the aforementioned applications, there is a lack of research on the joint suppression of interference by using multi-polarization information, and single-polarization data alone is insufficient in effectively mitigating interference. To address these challenges, this article presents a framework combining multi-polarization data to improve the performance of low-rank-based methods. Based on the proposed framework, experiments are conducted on real PolSAR data to assess the feasibility of the proposed framework in interference suppression. The results demonstrate that the framework significantly enhances the suppression performance of various low-rank-based methods with clearer scene details being recovered.