Range-doppler keystone processing for direct sampled radar data from targets with long range and high velocity using waveforms with high bandwidth, high duty factor, and long dwell

Abstract

A circuit comprises a receive processing window formation subsystem, a matched filter subsystem, a keystone interpolation subsystem, a phase modulation subsystem, and an image forming subsystem. The receive processing window formation subsystem forms, for each radar return from a scene, a receive processing window containing the radar return as an unbroken radar return. The matched filter subsystem creates a motion model for a reference point target disposed at a predetermined location within the scene, based on a set of motion compensation parameters for range and range rate, to compensate for at least some effects of fast time Doppler on the reference point target. The keystone interpolation subsystem rescales slow time information from the matched filter subsystem. A phase modulation subsystem applies phase modulations to a keystone-interpolated 2-D output array of information associated with the scene, to ensure proper registration in a range-Doppler map output of the scene.