Wide-area wide-angle SAR focusing

This study started with a data set that leveraged the latest autofocusing methods to obtain the cleanest radar data set appropriate for generating large SAR imagery over a 5-km spot. The authors intended to spotlight individual smaller nonmoving targets within the larger area; however, the images appeared blurred and varied greatly when generated by different passes of the circular SAR radar system. This study concentrated on using widely dispersed QTs combined with an algorithm to correct for both range and phase errors to improve imaging. The wide-angle QT imaging and vehicle identification experiments showed a significant improvement over all orbits and provided higher quality imagery to more robustly perform image registration. Focusing showed significant improvement in visualizations quad-trihedrals and a vehicle.