Squint looking synthetic aperture sonar imaging based on improved range-Doppler algorithm

Based on deep study of conventional range-Doppler (R-D) algorithm in synthetic aperture sonar, an improved R-D algorithm applied to squint looking and side looking by abandoning the Fresnel assumption is derived. Secondary range compressing is avoided and imaging effect is improved remarkably in squint-looking use. The steps in the algorithm are expressed only by Doppler center and Doppler rate, which can naturally realize motion compensation combined with auto-focusing steps. At last it is concluded that the modified algorithm is effective by squint-looking SAS simulation.