A High-Resolution Wide-Swath “Ambiguous” SAR Mode for Ship Monitoring

Abstract:
This paper proposes a novel high-resolution wide-swath synthetic aperture radar acquisition mode that does not require digital beamforming and can be employed for ship detection. This “ambiguous” mode achieves a wide elevation beam through tapering and uses pulse repetition frequencies much smaller than the nominal Doppler bandwidth, as azimuth ambiguities can be tolerated for this specific application. An example of implementation for TerraSAR-X shows that ground swaths of 120 km or 240 km can be mapped with 3 m azimuth resolution and outstanding detection performance even for small ships. This mode is furthermore straightforward to add to existing and future systems.