VHF-Band SAR for Detection of Concealed Ground Targets

摘要

Airborne synthetic aperture radar (SAR) operating in the VHF band and used in conjunction with change detection has shown promising results for wide-area surveillance of ground targets. By using VHF-band frequencies, both targets in the open as well as concealed by foliage may be detected in a robust manner. VHF-band SAR is able to detect hidden targets because both foliage attenuation and clutter backscatter is small. The clutter is further suppressed through the use of change detection, thus significantly reducing the false alarms. VHF-band SAR is suitable for change detection since temporal decorrelation is small. An extensive data base of VHF-band SAR and target data was collected during the summer of 2002. The primary goal of this collection was to evaluate VHF-band SAR change detection performance under various operating conditions. In general, the results show that a VHF-band SAR employing change detection can reliably detect truck-sized targets hidden in foliage. However, the detection performance deteriorates under certain operating conditions, e.g. for near-grazing angles.