Joint equalization filters that mitigate waveform-diversity modulation of clutter

Moving-target indication radars require advanced signal processing to be able to use pulse-to-pulse waveform diversity. The primary challenge is range-sidelobe modulation (RSM) of clutter. Because range sidelobes differ on each pulse, clutter energy that leaks into range sidelobes cannot be cancelled. We find that higher target SINR can be be obtained by joint design of the pulse-compression filters to obtain impulse responses that match across pulses. The proposed filters can reduce RSM by 5-10 dB compared to low-sidelobe mismatch filters designed separately for each pulse.

I. Introduction

High-power monostatic radars use pulsed transmissions because it is difficult to achieve sufficient isolation between the transmit and receive electronics without temporal separation. Moving-target indication (MTI) is a particular class of pulsed radar where returns from multiple pulses are coherently combined to cancel returns from stationary ground clutter and detect only moving targets.