Abstract: An angle tracking radar system particularly for a missile with a steerable antenna and gyros strapped down to the missile body—a ‘partially strapdown’ system. The body rate signals, body acceleration signals where provided, and target position signals are converted into an electronic reference frame which is controlled to align with the target sightline, the above body and target signals being employed to produce estimates of target direction, sightline rate and sightline acceleration for use in controlling the missile.

Abstract: A radar tracking system for an anti-aircraft, missile, including angle tracking, doppler tracking and range tracking feedback loops operating on sum and difference channels. Fast fourier transform digital filters are used to provide a frequency spectrum of the sum and difference I.F. channels and detection and confirmation algorithms are employed for selecting the F.F.T. target ‘bin’. Adjacent F.F.T. bins are used to simulate a bin centered on the target frequency, shifts of the latter with target/missile acceleration causing frequency errors which are detected by a discriminator and used to control the target I.F. Confirmation of target acquisition is achieved by successive summations of the target bin power the totals being accumulated and compared with upper and lower thresholds. Confirmation and rejection results from total levels outside the thresholds while further accumulation and comparison follow the intermediate condition.