New techniques for radar coherent range ambiguity resolution

A new method of target coherent range ambiguity resolution is presented which is substantially different from previously proposed methods. The new target ranging eliminates the generation of target ghosts associated with most conventional techniques. A range-ambiguous radar with a medium to high pulse repetition frequency is assumed. Clutter is assumed to be present in multiple range intervals. The method utilizes constant frequency pulses that change phase pseudo-randomly from pulse to pulse. The phase progression of the received pulses are correlated with a bank of matched filters constructed using phase progressions representative of the different range intervals. Performance degradation of target detection using the pseudo-random phases is also examined. Target detection with strictly pseudo-random phases is found to degrade in comparison to the conventional constant phase methods. A technique that utilizes both constant phase and pseudo-random phases is proposed that performs both detection and target ranging well