On-Board RFI Detection in Digital Beamforming SAR Systems using a Series of Digital Square-Law Detectors

A novel approach for dealing with Radio Frequency Interference (RFI) are auxiliary beams that become possible with Digital Beamforming (DBF) SAR systems. The formation of such auxiliary beams requires an on-board detection of RFI and it’s angle-of-arrival and is topic of this paper. A RFI detection scheme based on a series of digital squarelaw detectors is introduced. The dependence of the performance on the number of detectors and on the gain of the corresponding auxiliary beams w.r.t. the scanning SAR beam is investigated. Further, it is shown that the detection works well on downsampled data, which reduces the system complexity.