1. A system for radar detection of endo-clutter targets using tracker feedback, comprising: selecting an endo-clutter target to be tracked; tracking said endo-clutter target using a synthetic aperture radar (SAR) having a plurality of antenna channels; for each of a plurality of coherent processing intervals (CPIs): employing polar-format SAR pre-processing in a processor of a radar receiver device of motion-compensated phase history data for each said antenna channel; determining a location of a processed SAR image chip by converting track location and velocity into SAR image coordinates, wherein a size of said chip is proportional to a tracker error ellipse; compensating for defocusing due to target motion using an efficient one-dimensional moving reference processing (MRP) search over a single target defocus parameter expressed as a known function of said endo-clutter target and platform location, velocity, and acceleration; and performing space-time adaptive processing (STAP) on said SAR image chip using adaptive spatial antenna and temporal MRP degrees of freedom.