Radio Frequency Interference Suppression in Distributed SAR Constellations

Abstract

The growing demand for mobile telecommunication, television and radar systems are resulting in the increase of Radio Frequency Interference (RFI). Therefore, RFI is becoming an important factor on system sensitivity and severely degrading the image quality of Synthetic Aperture Radar (SAR) systems. Next generation SAR missions consist of distributed constellations with multiple receive satellites, opening new possibilities for RFI suppression. This thesis presents a novel RFI mitigation technique for distributed SAR constellations. The method is based on spatial filtering to extract the interference signal, using conventional beamforming techniques amongst satellites. The extracted interference is subtracted from the received SAR signal, resulting in RFI removal. The development of a simulator to investigate the mitigation technique is presented and its reliability and performance investigated. In addition, the procedure is studied for multiple satellite constellations and their results on the processed SAR images are presented and discussed. The results show a functioning method, although the SAR data in the position of the RFI and its vicinity is lost. The loss of data is determined by the number of satellites and their spatial constellation. Generally, the performance improves with increasing number of satellites and the loss of data decreases with increasing distance amongst satellites.