Patent Document ID: 20060152402
Application ID: 11031240
Patent Status: 0

Claim One:
1. A radar on a moving platform for generating a focused synthetic aperture image of a scene from a sequence of periodic pulse returns from said scene, said scene containing a target described by pixels within said synthetic aperture image, said pulse returns motion compensated for the motion of said moving platform with respect to said scene, said radar comprising: a monopulse antenna having a sum channel output and a difference channel output; a first analog to digital converter for converting said sum channel output into a sum channel digital stream; a second analog to digital converter for converting said difference channel output into a difference channel digital stream; said first analog to digital converter and said second analog to digital converter performing analog to digital conversion at a start time and a rate; a computer for: receiving said sum channel digital stream and said difference channel digital stream; generating a plurality of sum synthetic aperture image pixels from said sum channel digital stream; generating a plurality of difference synthetic aperture image pixels from said difference channel digital stream; computing a target ratio of said difference synthetic aperture image pixels to said sum synthetic aperture image pixels for said sum synthetic aperture image pixels descriptive of said target; computing background ratios of said difference synthetic aperture image pixels to said sum synthetic aperture image pixels for said difference synthetic aperture image pixels descriptive of a background around said target; computing a target least square fit of angle discriminant using said target ratios; computing a background least square fit of angle discriminant using said background ratios; comparing said target least square fit of angle discriminant with said background least square fit angle discriminant to identify an angle offset and a Doppler offset of said target with respect to said background.