Abstract

A pulsed doppler radar for detecting a moving target includes a plurality of antennae with patterns covering different spatial regions, wherein adjacent regions have overlapping spatial regions. Pulses having a predetermined carrier frequency are applied to the antennae in sequence. Energy from the pulses incident on the moving target is reflected back toward the antennae with a shift in carrier frequency. A plurality of signal processing channels, one for each antenna, are sequentially responsive to reflected energy transduced by the antennae associated with the channels. Each of the channels includes a doppler filter for passing a continuous wave replica of the shifted carrier frequency to the exclusion of the transmitted carrier frequency. Signals from adjacent channels are combined to derive signals representing sum and difference patterns of adjacent antennae. If any one of the sum or difference channel output signals has an amplitude greater than a predetermined value, a moving target indication is provided.