Multi-Aperture Coherent Change Detection and Interferometry for Synthetic Aperture Radar

• Main Author: Madsen, David D.
• Format: Others
• Published: BYU ScholarsArchive 2010
• Subjects: SAR; synthetic aperture radar; image registration; coherent change detection; CCD; interferometry; multi-aperture; repeat-pass interferometry; L-Band; backprojection; Electrical and Computer Engineering
• Online Access: https://scholarsarchive.byu.edu/etd/2075; https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3074&context=etd

Interferometry and coherent change detection (CCD) utilize phase differences between complex SAR images to find terrain height and to detect small changes between images, respectively. A new method for improving interferometry and CCD using multiple sub-apertures is proposed. Using backprojection processing, multiple sub-aperture images are created for a pair of flights. An interferogram and coherence map is made from each sub-aperture. For CCD, each sub-aperture coherence map offers an independent estimate of the coherence over the same area. By combining coherence maps, low coherence areas associated with residual motion errors are reduced, shadowed areas are minimized, and the overall coherence of stationary objects between images is increased. For interferometry, combining independent estimates of a scene's height offers a more accurate height estimate. For repeat-pass interferometry, multiple apertures are shown to increase the coverage of valid height estimates. The benefits of multi-aperture interferometry and CCD are shown using examples with real data.