Abstract: A star tracker for generating positional information for a vehicle includes a telescope 40 having multiple fields of view for imaging stellar objects. The telescope includes a plurality of radiation detectors 58 and an input lens 45 comprised of, in one embodiment of the invention, a plurality of holographic elements 45a and 45b. The holographic elements direct incident radiation originating from a plurality of stellar objects to an associated one of the radiation detectors. In another embodiment the multiple field of view telescope is comprised of a monocentric ball lens 80. The tracker may further include a multiplexer 60 for sequentially reading out a signal from each of the radiation detectors and a controller 62 coupled to the multiplexer for receiving the signals and for determining from the positions of the stellar objects imaged by the telescope a position of the vehicle.

Abstract: A method of, and apparatus for, eliminating the error-causing heat convections of a liquid which is disposed between a warm cylindrical float that houses a navigational gyro and a cool cylindrical gyro case that houses the float. The method includes the performance of steps which result in raising the temperature of the gyro case to the temperature of the float. The apparatus includes a temperature controller assembly which further includes temperature sensitive resistors to ascertain the temperatures respectively, of the float and of the gyro case; a differential amplifier to ascertain the difference in the temperatures; and a heater coil surrounding the gyro case to heat the case to the higher temperature of the float.

Abstract: An inertial measuring unit which precesses about the direction of apparent acceleration as a consequence of the introduction of a mass unbalance to each of the gyroscopes in the inertial measuring unit. The mass unbalances and the rotational moments of inertia of the gyroscopes are carefully controlled so that all gyroscopes within the inertial measuring unit precess at the same rate about any apparent acceleration. The precession of gyroscopes causes certain of the gyroscope errors to be averaged about zero thus reducing the error in the inertial measuring unit. The effect of precession upon the spatial orientation of the inertial measuring unit is compensated for by sensing the apparent acceleration and computationally compensating for the precession due to such acceleration.

Abstract: The azimuth shaft of an internally gimballed, gyro-stabilized platform assembly is maintained rigid by keeping the uniquely structured inertial instrument-mounting components neutrally buoyant in a flotation liquid that is captive within a spherical shaped outermost gimbal member. Unlike the prior art, this internally gimballed, gyro-stabilized platform assembly can be used for precision, and high-"g", applications.

Abstract: An apparatus is disclosed for generating a non-oscillating torque wherein a magnetic induction torquer having a first coil for clockwise torque and a second coil for counter-clockwise torque is utilized. The coils are selectively driven from a constant current source by way of an assembly of switches and associated precision dummy load impedances. A control circuit is driven by a torque command signal and a clock signal to selectively apply a plurality of control signals to the assembly of switches to cause current pulses to be directed to the appropriate coil or coils of the torquer in order to produce the commanded torque with no oscillating component in the resultant torque.