Abstract: A filter for use in an attitude control system which may be subjected to vibrations from disturbances which have frequency contents that vary with time. Sensors on the system produce signals that contain the disturbance frequencies and a calculator connected to the source of disturbance produces a signal which varies as a function of the disturbance. The filter receives these signals and augments the control loop gain at the disturbance frequencies thereby enabling the attitude control devices to null the disturbance effects on the attitude of the system.

Abstract: A feedback system for use in controlling control moment gyroscopes that are used in positioning a spacecraft where the relative rate of rotation is determined from the difference between the rotation rate of the gimbals of the CMGs and the rotation rate of the frame about the gimbal axis. The inertial reference units on the spacecraft are utilized as the source of measured rates of rotation of the three spacecraft axes with respect to a predetermined axis and these are converted to the rates of rotation of the frame about the individual CMG gimbal axes.