Linear and non-linear filters for clutter cancellation in radar systems

Abstract

The theme of this paper is the cancellation of clutter echoes in modern coherent radar systems. The receiver operating characteristics (ROC) of the following clutter filters are compared: (a) optimum linear filter, (b) the linear filter with Chebyshev tapering, and (c) the non-linear filter which takes the minimum between the outputs of few linear filters which process the same radar signals with properly selected weights. The non-linear filter offers a performance advantage, with respect to the widely used filter (b), in terms of detection capability of a target with Doppler frequency close to the clutter mean Doppler frequency. The non-linear filter requires, in general, five times the computation load of the linear filter (b) but is much less computationally expensive than the optimum linear filter (a).