Effects of receiver filtering on hot clutter mitigation

A typical jammer signal model is that of a jammer transmitting broad band white noise. This signal is then filtered (analog and digitally) prior to entering the adaptive processor. Among other effects, this band limits the signal and affects the correlation function of the jammer waveform as seen by the adaptive architecture. We illustrate some of the effects of varying receiver filters on the mitigation of terrain-scattered interference (otherwise known as hot clutter). We examine five different correlation functions, two of which are band limited, and three of which are limited in time. The results demonstrate that if the correlation function of this waveform has a finite time extent, then the ability to mitigate hot clutter is significantly reduced. This demonstrates that scatterers of long relative time delay (resulting in a small amount of correlation) still contribute significantly to hot clutter cancellation. This result may, for example, impact the choice of pulse compression used in a radar system, since pulse compression prior to adaptive processing will impact the resulting correlation function.