Passive SAR Range Resolution Enhancement Using Multiple DVB-T Channels

This paper presents an algorithm of improving the range resolution of passive synthetic aperture radar (SAR) images by combining multiple terrestrial digital video broadcasting (DVB-T) channels while also suppressing artefacts arising from the direct transmit-receive signal. The proposed algorithm has two parts: spectral estimation techniques for combining DVB-T channels and direct signal suppression (DSS) techniques based on modified CLEAN and sub-aperture imagery-based minimum pixel selection (SA-MIPS). Those capabilities can be achieved with a single-channel, wideband receiver and at shorter ranges and are thus consistent with drone-based operation. The performance of the techniques is demonstrated through both simulation and real-world experiments with a drone-based demonstrator.