On-Ground RFI Removal from SAR Images with DBF-based Measurements and Autoregressive Modelling

Abstract

The next generation of Synthetic Aperture Radar (SAR) instruments is capable of Digital Beamforming (DBF), which can suppress Radio Frequency Interference (RFI) via spatial filtering. However, previously presented RFI mitigation methods based on DBF are only effective while the instantaneous SAR return and the RFI originate from different locations. In the presence of in-swath interferers, short gaps, corrupted with RFI, remain in the data. This paper overcomes this limitation by measuring RFI while it is spatially orthogonal to the SAR signal. The extracted RFI is then used to estimate the interference in the remaining gaps with an autoregressive model.