Abstract: Each towed field artillery piece in a battery of field artillery pieces uses a heading reference system having a "slave" azimuth gyro, pitch and roll angle sensors and a readout display for correcting azimuth and elevation during a fire mission. A master system includes a "master" azimuth gyro which is mechanically lined up with the axis of the "slave" azimuth gyros in the heading reference systems. The master system transfers azimuth information to the slave system, whereupon the slave system acts as a repeater for the information given by the master to confirm congruency of the master and slave systems and provides the present location of the respective field artillery pieces.

Abstract: A gyrocompass navigation system for land vehicles is disclosed which includes self-contained heading and navigation means. The system determines the orientation of the vehicle with respect to grid north; provides land navigation information in universal transverse mercator (UTM) coordinates (northings and eastings); and provides range and bearing information for destination location. The system features a single degree of freedom gyroscope for both north seeking and navigational modes and further includes simplified means for tilt measurement and temperature compensation.

Abstract: Gyrocompassing apparatus for stationary equipment is disclosed which provides heading and two-axis tilt information while utilizing a minimum complement of relatively low cost components. The apparatus features a single degree of freedom gyroscope mounted to a mechanical levelling and indexing arrangement for implementing a gyrocompassing routine. Tilt information is provided with relatively high accuracy via a two-axis pendulum mechanization. A microprocessor with associated peripherals provides required control, compensation and computational functions.

Abstract: Electrical and mechanical synchronization of two or more synchronously driven gyroscopes, mounted on the same platform, to minimize cross-talk induced drift, is achieved by bringing one gyroscope to a speed which is slightly higher than the other by driving it at a slightly higher frequency. At speed, coincidence of mechanical position is established by means of signals from pick-offs on each gyro and the drive for the faster gyroscope is shifted to the lower frequency. Electrical synchronism is established by restarting the lower frequency generator to instantaneously establish a predetermined relationship between a pick-off signal and the frequency generator. Phase-lock start-up of a single gyroscope by instantaneous shift of the phase of the driving voltage, relative to the gyroscope wheel position, is also provided.

Abstract: A dry tuned two axis gyro having a pulse-rebalanced rate capture loop control. This configuration eliminates the need for an analogue-to-digital converter since the gyro is torquered at a pulse rate using a constant current source. Another feature of the control loop is a cross-channel shaping network which exchanges an electronically damped error from one axis to the other axis. By means of a summing network which combines the error signals from the main channel and the cross channel with a source of time varying ramp voltage, an alternately negative to positive signal is applied to the gyro torquer.