Abstract: A digital processor for radar signals which can perform adaptive suppression of the disturbance clutter and enhancement of the useful signal of given Doppler frequency. It can approximate the principle of operation of the optimum processor, which is that processor which maximizes the signal-to-noise ratio. Such processor can also cancel, in a adaptive manner, a clutter component having an approximately Gaussian power spectrum.

Abstract: A digital MTD processor interposed between a coherent video detector and a signal extractor of a surveillance radar comprises a plurality of Doppler filters connected in parallel to the video-detector output, including a zero filter, working into respective modulus extractors connected by way of respective threshold circuits to a common OR gate. Each threshold circuit includes a fixed-threshold comparator and an adaptive-threshold comparator with inputs connected in parallel to the output of the associated modulus extractor, either of these comparators being connectable to the OR gate via a switch controlled with the aid of a rain-clutter map so that the adaptive threshold is used only during exploration of regions with heavy rain.