Passive SAR imaging using the ASAR instrument of ENVISAT as transmitter of opportunity

Inhalt:
The ASAR instrument of ENVISAT can operate in ImageMode (stripmap-likemode) and in ScanSAR mode (burst mode) in which five sub-swaths are used to image large swaths at the expense of azimuth resolution. The poor azimuth resolution of the ScanSAR mode in monostatic configuration can be enhanced in the case of a bistatic configuration with a receiver close to the imaged area by using the sidelobe emissions of the beams illuminating the adjacent sub-swaths in addition to the mainlobe emissions of the beam illuminating the considered sub-swath. In this paper, we describe the exploitation of the low azimuth resolution ScanSAR modes of the ASAR instrument and assess how the azimuth resolution can be improved from the nominal azimuth resolution based on real data acquired by a ground-based receiver.