Time Reversal Synthetic Aperture Radar Imaging In Multipath

Conventional spotlight synthetic aperture radar (SAR) assumes a single reflection of transmitted waveforms from targets [1]. Multiple reflections of targets due to surrounding scatterers appear as ghosting artifacts in conventional SAR images, which obscures true target image and leads to poor resolution. In this paper, we develop image formation techniques using time reversal, time reversal SAR (TR-SAR), to remove ghosting artifacts and achieve high resolution. The TR-SAR algorithm is tested using phase history data collected by a rail-mounted SAR sensor operated by Raytheon.

1 Introduction

Many data adaptive high resolution approaches to synthetic-aperture radar (SAR) image reconstruction have been developed [2], [3]. Our work is concerned with the exploitation of time reversal in spotlight synthetic aperture radar imaging in multipath rich environments. For targets in a rich scattering environment, conventional SAR results in ghosting artifacts due to multiple bounces by surrounding scatterers. To counter this, we develop time reversal SAR algorithms to process phase history data in rich multipath scattering. The ultimate goal of TR-SAR is to improve automated target recognition and to aid image analysts in identifying targets in dense multipath.