Detection and Mitigation of Mutual RFI in C-band SAR : a Case Study of Chinese GaoFen-3

Radio frequency interference (RFI) usually mixed into the synthetic aperture radar (SAR) system as a direct wave, which can significantly degrade the SAR image quality, including amplitude, phase and geometry, etc. In this paper, a new form of RFI, namely the mutual RFI (MRFI), which is a kind of scatter-wave RFI originating from the nearby ground area simultaneously illuminated by different SAR satellites, was investigated. In order to solve the issue of MRFI, a novel RFI detector based on spectrum energy cancellation (SEC) and a RFI mitigation technology based on improved eigen-subspace projection (ESP) method are proposed. In this work, a systematic analysis of MRFI is performed, and the proposed mitigation process is introduced. Finally, experiments accomplished over GaoFen-3 single look complex (SLC) data confirm the effectiveness of the proposed technique.