Correction and Characterization of Radio Frequency Interference Signatures in L-Band Synthetic Aperture Radar Data

TLDR

Radio frequency interference is a known problem in low‑frequency radar remote sensing and can severely degrade synthetic aperture radar image quality, distort polarimetric signatures, and increase phase noise. The authors developed a processing system that reliably detects, characterizes, and mitigates RFI signatures in SAR observations, with the extracted information intended to inform SAR‑system design, sensor operations, and mitigation strategy development. The system employs robust RFI‑detection algorithms that correct images and enable large‑scale mapping, characterization, and classification of RFI signatures, outlining concepts of detection, analysis, and mapping. Large‑scale RFI mapping results are presented, and case studies illustrate how detailed RFI information improves customized filtering and sensor operations.

Abstract

Radio frequency interference (RFI) is a known issue in low-frequency radar remote sensing. In synthetic aperture radar (SAR) image processing, RFI can cause severe degradation of image quality, distortion of polarimetric signatures, and an increase of the SAR phase noise level. To address this issue, a processing system was developed that is capable of reliably detecting, characterizing, and mitigating RFI signatures in SAR observations. In addition to being the basis for image correction, the robust RFI-detection algorithms developed in this paper are used to retrieve a wealth of RFI-related information that allows for mapping, characterizing, and classifying RFI signatures across large spatial scales. The extracted RFI information is expected to be valuable input for SAR-system design, sensor operations, and the development of effective RFI-mitigation strategies. The concepts of RFI detection, analysis, and mapping are outlined. Large-scale RFI mapping results are shown. In case studies, the benefit of detailed RFI information for customized RFI filtering and sensor operations is exemplified.