Experimental study of extended target imaging by time reversal SAR

Conventional SAR images under rich scattering suffer degradation because of ghost images caused by multipath propagation. In this paper, we develop a time reversal SAR (TR-SAR) imaging algorithm for extended (nonpoint-like) targets in rich multipath scattering. We test the TR-SAR algorithm using experimental electromagnetic data collected in a laboratory environment where the extended target (a galvanized steel sheet) is surrounded by a large amount of PVC rods. Our experiments show that the collected EM data in frequency and aperture after TR-SAR processing produces a higher resolution, cleaner target map compared with conventional SAR images.