Fast-time filtering with multichannel SAR

Abstract

Large regions of a Synthetic Aperture Radar (SAR) image can potentially be destroyed by an airborne broadband jammer. Jammer components include both the direct-path and multipath reflections from the ground, known as hotclutter or terrain scattered interference. Using multiple antennas on a SAR provides spatial degrees of freedomand allows for beamforming to reject the direct-path signal. However, to effectively suppress non-stationary hot-clutter components, fast-time taps fromwithin a pulse have shown to be effective for airborne radar, [1]-[2]. The goal of interference suppression for SAR is to successfully suppress these interferences while not significantly effecting the image quality by blurring, reducing the resolution or raising the side-lobe level. This paper looks at two fast-time STAP algorithms, the Minimum Variance Distortionless Response (MVDR) and the Generalised Sidelobe Canceller (GSC) to study the effect of non-stationary interference suppression for SAR images.