Abstract: A mode scheduling system for selecting track or search dwells in a track-while-scan radar. Targets to be tracked are classified according to acceleration levels and then arranged into priority classes based upon the acceleration. A relative update frequency for the targets in the priority classes is established. The track and search dwells are made during a repetitive dwell period having a predetermined number of track dwell intervals. Track dwells are scheduled during these intervals to satisfy the update frequency requirements. When all of the track dwell positions are not needed, search dwells are substituted for some of the track dwells. Search dwells are also inserted between track dwells, as needed, to maintain a minimum amount of search time regardless of the number of targets being tracked.

Abstract: A pulse radar for acquiring a target while rejecting the altitude line is described wherein a plurality of target reports from a scanning antenna are examined and rejected if the pattern of target reports at an apparent range extends along a scanning angle too large to be a valid target and selected if the pattern of target reports at a range extends along a limited scanning angle indicative of a target having a valid target size. Target reports rejected during a prior scan may be used as a basis for rejecting target reports of a current scan.

Abstract: A medium to low PRF pulse doppler radar wherein the effect of the clutter notch filter is eliminated at times when the doppler frequency of the target approximates the doppler frequency of the clutter to continue tracking the target provided that the doppler frequency of the target and clutter are at different ranges.

Abstract: A receiver and method for detecting a Manchester coded waveform is disclosed. The waveform is clocked to provide a number of digital samples of each positive and negative pulse. Each positive pulse is validated provided that a predetermined number (k) of the total samples (N) is more positive than a positive (+T) threshold level and a predetermined consecutive number (j) of the samples (N) are more positive than a negative (-T) threshold level. Each negative pulse is validated provided that (k) of (N) samples is more negative than the -T threshold level and (j) of (N) are more negative than the +T threshold level. Each data bit pulse synchronizes each succeeding data bit pulse by providing a predetermined time interval during which the midpoint of each pulse must change between a positive and negative waveform.