Tracking system tracker unit

Claim 1

In a tracking system tracker unit which develops azimuthal and elevational tracking error correction signals from a television camera sensor video signal, in combination: a. First pulse generator circuit means generating, in response to a target edge-like contrast characteristic, detected in the television camera sensor video signal, a pair of marker pulses spaced-apart in a line of scan of the television camera sensor by a time interval, b. Second pulse generator circuit means generating an elevational tracking gate pulse having a time duration iN a field of scan of the television camera sensor in excess of a line of scan of the television camera sensor for coincidence gating at least one of said pair of marker pulses during concurrent system azimuthal tracking to develop the elevational tracking error correction signal, c. Third pulse generator circuit means generating an azimuthal tracking gate pulse having a time duration in a line of scan of the television camera sensor less than said marker pulse spacing time interval for coincidence gating one of said pair of marker pulses on a singularly coincident basis during concurrent system elevational tracking to develop the azimuthal tracking error correction signal, d. Fourth pulse generator circuit means generating a pulse extension for said azimuthal tracking gate pulse in a line of scan of the television camera sensor, e. AND gate circuit means gating one of said marker pulses coincident in time with said elevational tracking gate pulse and a pulse indicating concurrent system azimuthal tracking as a tracking error detection pulse for developing the elevational tracking error correction signal, and f. Circuit means combining said azimuthal tracking gate pulse and said pulse extension into a combination pulse and providing said combination pulse to said AND gate circuit means as said pulse indicating concurrent system azimuthal tracking.