Abstract: A gyrocompass has a gimbal (18;218) rotatable about an upright axis (22;222) and a gyro (10;210) rotatably mounted in this gimbal (18;218) about an inner axis (16;216) transverse to the upright axis (22;222). The gyrocompass also includes a level sensor (30,32;230,232) supported by the gimbal (18;218) for providing a level signal signifying the tilt of the upright axis (22;222) from vertical. Also included is a controller (50) connected to the level sensor (30,32;230,232). The controller includes equipment (50) responsive to the level signal for rotating the gimbal (18;218) into an initial position (SP(1)) at which the level signal has a predetermined value. A method employing the foregoing apparatus includes the steps of rotating the gimbal (18;218) until the level sensor (30,32;230,232) indicates the inner axis (16;216) is horizontal.

Abstract: A dual suspension gyroscopic device includes a gyro having at least a single degree of freedom and defining an output axis, i.e., the sensitive axis of the gyroscopic device. The gyro is supported by a gimbal which in turn is supported in a case for unlimited angular displacement about the gimbal axis. The arrangement provides low torque suspension about the sensitive axis while permitting normal angular displacement about said axis and maintaining the gyro spin axis in a reference plane. A data transferring slip ring assembly is arranged with the gimbal support and the slip ring assembly and support arrangement is powered to minimize friction about the gimbal axis.

Abstract: A rate integrating device includes a torquer in open loop configuration for torquing the device to null and a load connected to the device in closed loop configuration for maintaining the device at null. The load loop includes electrical means whereby the maintenance of the device at null is controlled independent of its dynamic characteristics for increased accuracy and stability.