Detection and Geolocation of P-Band Radio Frequency Interference Using EcoSAR

The high penetration of P-band signals (300-600 MHz) into dense vegetation and the higher temporal stability at low frequencies are key advantages for the estimation of forest properties using synthetic aperture radar (SAR). However, existing services at those frequencies make P-band SAR imagers more vulnerable to the radio frequency interference (RFI). In this paper, a method to detect and geolocate the RFI using digital beamforming (DBF) is presented. The method is implemented using NASA's EcoSAR measurements. This P-band multichannel radar uses a sniffing pulse interleaved during the DBF SAR operation to sense the RFI. RFI detection is implemented with time-bandpass filters while DBF is used to estimate the angle-of-arrival and geolocate the interference. The method is demonstrated for an interferer how EcoSAR could be used to assess the RFI threats to spaceborne missions.