AN EXPERIMENTAL STUDY OF ENHANCEMENT OF THE CROSS-RANGE RESOLUTION OF ISAR IMAGING USING ISDB-T DIGITAL TV BASED PASSIVE BISTATIC RADAR

Passive bistatic radars (PBRs) exploit existing transmitters such as TV broadcasts, radio broadcasts, Global Navigation Satellite System (GNSS), etc., as the source of illumination. PBR consists of two receivers, with one antenna pointed at the source and the other at the target, and the target range is determined by correlating the signal scattered by the target with the signal directly arrived at the receiver. Since PBR dode not transmit any wave form, it consumes lower power, and no frequency allocation is required. We are investigating the tharget imaging capability of PBR. In This paper an experimental study on obtaining Inverse Synthetic Aperture Radar (ISAR) image with cross-range resolution of a few meters, using terrestrial digital TV baseb PBR. In this study, we conducted a field experiment to observe some aircraft targets. Due to the relatively low frequency band employed by the digital TV broadcast system, a very wide synthetic aperture angle is required to obtain a few meters cross-range resolution. Using the data acquired in the experiment, we show the limit of the range Doppler processing approach and we investigate the advantage of the Polar Format Algorithm (PFA). We also discuss the issue on autofocus and show results of initial study on autofocus algorithms.