Characterization and correction of residual RFI signatures in operationally processed ALOS PALSAR imagery

This paper analyzes severe, broadband, radio frequency interference (RFI) signatures that are commonly observed in L-band ALOS PALSAR images acquired in the American Arctic. A spatial and temporal analysis of RFI distortions is presented, showing widespread contamination of L-band SAR especially near the American Arctic coast. The specific time frequency signature of the interfering signals is introduced and it is demonstrated that standard notch filtering algorithms, such as those used in the operational ALOS PALSAR processor, are insufficient for their removal. A new approach for RFI reduction is presented and its performance for correcting image quality, polarimetric signature, and interferometric phase is demonstrated.