Patent ID: 7145498
Filing Date: 2006-12-05
Classification: G01S

Abstract:
1. A radar for generating a search mode synthetic aperture image of a patch from periodic pulse returns reflected from said patch, said radar having a motion, a first number of said periodic pulse returns reflected from a first array and a second number of said periodic pulse returns reflected from a second array, said first array overlapping said second array by an overlap, said first array and said second array covering said patch, said radar comprising: analog to digital converter for converting said pulse returns from said first array into a first digital array having first range bins and from said second array into a second digital array having second range bins; a computer for: locating a first strong scatterer within said first digital array; locating a second strong scatterer within said second digital array; motion compensating said first digital array with respect to said motion during said first digital array and said first strong scatterer to obtain a motion compensated first digital array; motion compensating said second digital array with respect to said motion during said second digital array to obtain a motion compensated second digital array; autofocussing said motion compensated first digital array to obtain a first phase error estimate over said first digital array; autofocussing said motion compensated second digital array to obtain a second phase error estimate over said second digital array; adding an optimizing phase to said second error estimate to obtain a shifted error estimate for said second array; merging said first phase error estimate and said shifted error estimate over said overlap to obtain a connected phase error estimate; applying said connected phase error estimate to said motion compensated first digital array and said motion compensated second digital array to compute an image of said patch.