Shift-Scale Complex Correlation for Wide-Angle Coherent Cross-Track SAR Stereo Processing

• Published in: IEEE transactions on geoscience and remote sensing Vol. 45; no. 3; pp. 576 - 583
• Main Authors: Yocky, D.A., Jakowatz, C.V.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive optics; Algorithms; Angles (geometry); Applied geophysics; Automation; Coherence; coherent processing; Correlation; Data mining; digital terrain map (DTM); Distortion; Earth sciences; Earth, ocean, space; Electromagnetic scattering; Exact sciences and technology; Geometry; image registration; Internal geophysics; Laser radar; Optical distortion; Optical imaging; Optical interferometry; Optical scattering; Searching; spotlight-mode SAR; stereo SAR; Synthetic aperture radar; synthetic aperture radar (SAR); Terrain; ground truth; Automation; maps; coherent processing; image registration; data processing; remote sensing; rupture; synthetic aperture radar; airborne methods; correlation; synthetic aperture radar (SAR); imagery; digital terrain models; geometry; relief; slope angle; spotlight-mode SAR; digital terrain map (DTM); errors; stereo SAR; distortion
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2006.886193

Automated synthetic aperture radar (SAR) stereo correspondence becomes increasingly difficult when imaging high-relief terrain utilizing large stereo crossing-angle geometries because high-relief SAR image features can undergo significant spatial distortions, causing a failure of traditional correlation matching. This paper presents eight coherent spotlight-mode cross-track stereo pairs with stereo crossing angles averaging 93.7deg collected over a terrain with slopes greater than 20deg. These stereo pairs suffer from terrain-induced distortions, resulting in a decrease in complex correlation (coherence) when utilizing scanning-window correlation calculations. The search to maximize complex correlation is changed from a shift-only (disparity) search to a shift-and-scale search using the downhill simplex method. This approach is tested against complex imagery with simulated distortions and then employed on the eight wide-angle stereo collects. The resulting digital terrain maps (DTMs) are compared to ground truth. Using a shift-and-scale correlation approach to estimate disparity, the relative height errors decrease, and the number of reliable DTM posts increase