Abstract: A method and system for inducing and controlling nutation of a gyroscope momentum wheel (or member) so that such controlled nutation can be used for purposes such as target searching, acquisition and tracking, particularly in a guided missile system. A nutation command signal having a frequency integrally related to the natural nutation frequency of the gyroscope momentum member is generated, preferably is response to a momentum member position feedback signal. The generated nutation command signal is applied to a torquer to induce movement of the momentum member at the frequency of the nutation command signal. The amplitude of the nutation command signal is selectively controlled to control the amplitude of the induced movement and thereby control the movement of the momentum member through a desired pattern. In the disclosed embodiment, the momentum member controls the line-of-sight of a sensor such as a light or other electromagnetic wave energy detector.

Abstract: A monopulse radio direction finding and tracking system having the capacity of detecting the presence of multiple radiating sources within the effective beamwidth of the monopulse antenna and causing the monopulse antenna to move toward and align its boresight with one of the multiple sources. Signal processing is provided that implements an algorithm based on the amplitudes and absolute magnitudes of signals from a receiver sum channel, elevation and azimuth difference channels, and elevation and azimuth angular error channels. The algorithm utilizes the differences in the ratio of signals present in these channels when a single radiating source is present and when multiple sources are present. Steering control circuits are provided that bias the azimuth and elevation antenna steering servo system to cause the antenna to align its boresight with one of such multiple sources.