GB1212265A - Improvements in or relating to radar pulse length discriminator circuits - Google Patents

Abstract

1,212,265. Radar pulse discriminators. MINISTER OF TECHNOLOGY. 6 May, 1969 [15 May, 1968], No. 22983/68. Heading H4D. In a discriminator (Fig. 1) for separating wanted radar echo pulses from unwanted longer pulses, the radar video channel excites a pulsator circuit 1 generating reciprocal differentiated pulses from the leading and trailing edges of the unwanted and wanted pulses respectively; a delay circuit being triggered on a negative pulse to generate an output pulse of target echo form and preset duration, whose trailing edges triggers a monostable to produce a delayed target pulse. A further monostable is triggered direct by a negative-going pulse of the reciprocal waveform to produce a target pulse, and the monostable outputs are applied to a coincidence gate, whose output develops a target echo pulse of width equivalent to the delay at 2; such output pulse (Fig. 2, not shown) not being produced by input pulses exceeding a target echo pulse in duration (e.g. from precipitation) but an output pulse being produced by an input pulse of target echo duration, whether or not superimposed on a signal of longer duration.