Passive synthetic-aperture radar for detection of ground vehicles

Synthetic-aperture radar (SAR) provides images with high spatial resolution for ground surveillance applications. As is well known, intentional interference may limit this capability. Passive SAR, on the other hand, uses non-cooperative illuminators of opportunity and is thus less susceptible to counter-measures since no transmit signals of its own are used. In this paper, we report on an experiment to investigate the potential of using airborne passive SAR for imaging of ground vehicles. The airborne LORA system, in receiver-only mode, acquired direct and reflected signals originating from two 8-MHz digital TV (DVB-T) channels centered at 530 and 594 MHz, respectively. The experiment included two different target deployments for repeat-pass analysis. Results give evidence that vehicles may be successfully imaged and detected by change detection.