Characterization and Mitigation of RFI Artifacts in Operationally Processed LuTan-1 Imagery

LuTan-l satellite is China's first L-band distributed spaceborne interferometric synthetic aperture radar (InSAR) mission, serving land resource management, mapping, forestry, and disaster preparedness purposes. However, the presence of radio frequency interference (RFI) in the shared L-band spectrum poses a significant threat to obtaining a high-quality digital elevation model (DEM) and deformation monitoring. This paper examines RFI issues in LuTan-1 InSAR mission, derives interference echo model, and analyses adverse impact on interferometric coherence. An automated RFI detection and mitigation pipeline is proposed for the Lutan-1 ground processing system, capable of managing massive image datasets without manual tuning parameters. Experiments with real LuTan-1 mission data, including various scenarios and RFI instances, demonstrate the proposed scheme's effectiveness in eliminating RFI artifacts and improving image quality and coherence. This solution has been integrated into LuTan-1's processing pipeline for practical use.