Random Frequency Shift Interference Suppression Technology Based on Multi-Channel SAR

The imaging output of Random Frequency Shift Interference (RFSI) signal is a noise like band occupying a certain width in the distance direction, which can be used to suppress distributed targets. By utilizing the angle Doppler relationship of SAR signals and their ability to achieve effective decomposition (projection) in the Doppler domain, this paper proposes a space-time joint adaptive filter based on Doppler constraints. Combined with a multi-channel SAR system, it can effectively suppress RFSI signals. Firstly, analyze and estimate the spatiotemporal spectrum of the effective signal and RFSI, and then process the oblique MSAR data. Use the subspace projection matrix to remove the interference and use the Multi Doppler Direction Linearly Constrained Minimum Variance (MDD-LCMV) beamformer to reconstruct the signal spectrum. This article verifies the effectiveness of the proposed algorithm through simulation experiments.