Ground mapping using active and passive UHF-band SAR

Synthetic-aperture radar (SAR) is normally used in an active mode for ground surveillance. Passive SAR has also been demonstrated using DVB-T (Digital Video Broadcasting – Terrestrial) signals from TV-broadcasting masts as illuminators of opportunity. However, simultaneous active and passive SAR have not yet been demonstrated. In this paper, we compare active and passive SAR and describe a system which can perform acquisition of both active and passive UHF-band SAR-data onboard an airborne platform. We also show, for the first time, active and passive SAR images processed from data acquired during the same flight.