Coherent Sub-Aperture Processing Techniques for Synthetic Aperture Radar

摘要

Coherent sub-aperture techniques for processing synthetic aperture radar (SAR) signals are described. The techniques involve partitioning the full aperture data, in either the time or the frequency domain, Each partition or sub-aperture is then processed independently by the application of a conventional matched filter, or the equivalent. The low resolution images formed by this process are then coherently recombined to form a full resolution image. Such a processing scheme has the advantage of high computational efficiency and provides the capability for the compensation of low frequency spurious motions, even when the SAR is operating in a highly squinted, high resolution imaging situation. A detailed description of two coherent sub-aperture techniques namely, the multi-look matched filtering approach and the step transform, are presented. The techniques are characterized and the normal computational requirements are evaluated. Computer simulations, which were performed to verify the feasibility for the processing schemes, are also described.