Doppler processing of square-complementary coded radar signals

Sidelobes in radar filter output may be avoided by using a set of modified Golay-coded pulses separated in frequency, and performing a nonlinear filtering operation on the radar returns. However the nonlinear operation introduces cross-terms which hamper detection in clutter. This study considers the Doppler processing of a train of frequency-separated square-complementary pulses. It is shown that the cross-terms have a dependence on offset frequency, and that the manifestation of cross-terms in Doppler can be controlled by slowly varying the offset frequency with each pulse. Simulations demonstrate the ability of this method to expose weak returns masked by strong clutter.