Abstract

An electronically agile multi-beam radar including a clutter positioning system for positioning the band of clutter signals in the derived doppler frequency spectrum of each of the individual beams is disclosed. The radar is operative to switchedly transmit a plurality of beams directionally separated by time sharing the illuminating power thereof. Each beam includes at least one transmission of a plurality of R.F. pulses constituting a radar look. The radar is also operative to receive echo R.F. pulses of the look from each transmitted beam dispersed in time with echo R.F. pulses of the looks of the other transmitted beams of the plurality. The clutter positioning system operates to maintain substantially a desired pulse-to-pulse phase relationship for the received plurality of echo pulses of each look of each beam in a time-shared manner in order to derive a substantially representative pulse doppler spectrum of signals associated with each look of the transmitted beams and to adaptively position an identified group of clutter signals about a prespecified dopper frequency in a derived doppler frequency spectrum for each look of each beam. The clutter positioning system may be disposed in either the transmission portion or the reception portion of the radar in which case it effects substantially the desired pulse-to-pulse phase relationship at each transmitted or received R.F. pulsed beam, respectively.