Patent ID: 7053815

Claim:
A monopulse radar tracking system, including (A) at least one of a Doppler tracking loop and an angle tracking loop; (B) means for deriving from a target echo an intermediate frequency (I.F.) signal; (C) means for estimating an I.F. target signal frequency periodically; (D) digital filter means providing a frequency analysis of signals in the I.F. band; (i) the characteristic of said filter means comprising a plurality of similar, sequential, overlapping, peaking characteristics, defining respective adjoining frequency bins, (E) means for producing from a first pair of adjoining frequency bins a derived bin characteristic similar to said peaking characteristics, (ii) from a second pair of adjoining frequency bins a further, similar derived bin characteristic, (iii) the two derived bin characteristics lying symmetrically astride the estimated target signal frequency, (F) means for controlling the position of said two derived bin characteristics continuously, and (G) means for determining the frequency error between the target signal frequency and the centers of said two derived bin characteristics and effectively sliding said two derived bin characteristics to re-center them on the newly determined position of the target signal.