Abstract: Gyro drift is reduced by measuring the positional relation between the rotating field of a driving synchronous gyro motor and a reference point on the gyro rotor at start-up. After the measurement is made, it is adjusted to a pre-established fixed value. Adjustments to the pre-established value occur each time the gyro is started.

Abstract: To provide improved performance in a microwave antenna, particularly for use in a Doppler navigation system, rectangular arrays obtained from truncated slanted arrays are used to obtain beam shapes which exhibit a high degree of independence from over-water shifts.

Abstract: A phase shifter of a signal processor which involves separation of the cell signals from a magnetic resonance gyro (MRG) using phase locked loops that also serve as frequency multipliers, phase shifting one cell output to maintain phase comparisons within the monotonic region of the phase detectors, PDM/Digital conversion of the MRG signals and finally microcomputer processing to obtain gyro angle to the required resolution and update rate.

Abstract: The present invention operates on the principle that the velocity vector of a land-vehicle is along the longitudinal axis of the vehicle. The invention uses an odometer in conjunction with a set of three single axis rate gyros strapped down to the vehicle to provide a land vehicle navigation system. The single axis rate gyros are rigidly mounted to the body with input axes parallel to a set of reference axes in the vehicle. By means of these gyros it is possible to infer the heading of the vehicle and thereby achieve a navigation accuracy comparable to the accuracy that the same gyros would provide in a gimballed system, but without the necessity for the set of gimbals.

Abstract: A ring laser gyro is electromechanically oscillated so that oppositely moving light beams in the gyro do not exhibit an undesirable lock-in effect. A piezoelectric transducer mounted in the gyro measures the dither. Analog/digital circuitry converts the measurement to digital dither signals. A non-compensated beam combiner and photodetector assembly are integrally mounted to the gyro for producing beam frequency outputs from the light beams, indicative of inertial rotation of the gyro. The beat frequency outputs and dither signal are input to logic circuitry which eliminates the effect of the dither signal on the beam frequency output signals.

Abstract: An impedance is connected by a switching circuit, to sense/inhibit windings of a core memory at the end of each memory cycle. The result is an effectively decreased time constant for the core windings which permits faster memory operation. The circuit further reverse biases diodes connected to the input terminals of a sense amplifier during a read cycle thereby increasing the isolation of this amplifier from the effects of inhibit current pulses occurring during a memory read cycle.

Abstract: A gyro motor supply provides an alternating signal to a gyro hysterisis motor. A detector senses the passage of a reference point on the gyro flywheel during each revolution thereof. A logic circuit is driven by the detector output and controls the phase of the alternating signal thereby ensuring a repeatable gyro start-up condition wherein the phasing is fixed between the reference point on the flywheel and a vector of the rotating field of the motor.

Abstract: A gyro includes piezoelectric force transducers which are oscillator driven. As the gyro undergoes angular displacement, the oscillators "follow" the instant natural frequency of the transducers and FM signals are generated at the oscillator outputs which are processed by the present invention to produce digital signals proportional to gyro angular inputs and resolved about two axes.

Abstract: In order to provide an all-angle gradient magnetometer, first and second magnetic resonance cells are mounted to a common base and separated by a predetermined distance. Circularly polarized pumping light is passed through the two cells orthogonally. Mixed with the circularly polarized pumping light is readout light which is linearly polarized. At the output of the cells appropriate filters are provided to filter out the pumping light whereafter the modulated readout light is detected in push-pull manner and fed back to modulate the pumping beams and at the same time fed to signal processing means to permit detecting phase differences between the outputs of the separated cells.

Abstract: Separate photodetectors and preamplifiers of prior art path controllers are replaced with an electronic circuit using the outputs of gyro fringe detectors. A ring laser gyro ordinarily includes fringe detectors for producing a data signal. Thus, the same detectors are used to serve two purposes. Pathlength controller simplification and cost reduction is thus realized since it is unnecessary to mount and align separate photodetectors to a gyro and to connect these photodetectors via flexible connections to a vibrating gyro.

Abstract: A dual speed resolver to digital conversion system with coarse and fine interlocking. The reference frequency is utilized to drive a bang-bang servo loop under priority control of the coarse mathetics when it is necessary to pass control to the coarse loop.

Abstract: A switching circuit turns on at the beginning of a first clock signal and turns off in response to a gyroscope shaft detector signal. During the time the switching circuit remains on, a counter counts the cycles of a second clock signal. This resultant count is employed as an error signal for adjusting the output frequency of a pulse generator which is connected to a gyroscope motor. A feedback loop is created between the aforementioned components for achieving a preselected constant gyroscope motor speed.

Abstract: A method and apparatus for regulating the anode current of a gas lasing system with reduced power dissipation is disclosed. According to this invention a feedback loop is connected between the anode circuitry and the high voltage power supply such that the anode current regulator has a much lower voltage across itself than has been the case in the past. Since the voltage across the current regulator is reduced, there is not nearly as much power for the regulator to dissipate. In addition, because of the smaller power handling requirements, a stabilized anode current can be achieved at about half the level required by prior art circuitry. Thus, the power dissipation can be reduced even further.

Abstract: A comparator network in a successive approximation synchro-to-digital converter uses two comparators to determine the quadrant of the synchro angle and then uses one of these comparators as a steering voltage comparator to determine the less significant bits of the synchro angle. Fractions of the sine and cosine analog inputs are cross-coupled to the comparators to provide inherent quantization error centering.

Abstract: A method and apparatus for receiving and correlating coded digital information with increased anti-jamming capability. The apparatus uses a receiver for each pair of frequencies at which the information is transmitted, a synchronizer for synchronizing the transmitter and receives, a correlator and a code sequence generator. The receiver is alternately operated at one of two frequencies over a predetermined period, and each correlator is provided with a number of sections equal to the maximum number of codes to be transmitted at each of the frequencies.

Abstract: A machine for manufacturing high strength flexure hinges having use in accelerometers. A source of metal material is splat-cooled after it has been heated to a molten state. An induction heater heats the metal material to the molten state and the molten metal is rapidly cooled while being pressed between two water cooled wheels. The wheels are provided with indentations and protuberances on their surfaces to produce flexure hinges and strengthening beams. A chute is provided to catch the flexures as they leave the wheels preventing damage to them.

Abstract: A method and apparatus for phase locking the dither motions of a set of ring laser gyroscopes are shown. To prevent a variation of force from existing on a strapped-down sensor block having a plurality of ring laser gyroscopes means are provided permitting only one gyroscope to determine the frequency of oscillation of its dither suspension system. The remaining gyroscopes are slaved in both frequency and phase to the reference rather than acting independently, or locked in frequency only. The circuitry for the master and slave units have similar components, and operate substantially the same except that the signal from the variable frequency oscillator of the master unit is used as the second input to the phase detectors of the slave units rather than them using the output of their own variable frequency oscillators.

Abstract: A phase locked loop circuit employing a first edge detector consisting of an exclusive OR gate and flip flop circuit feeding by way of a NAND gate, an up counter and a second edge detector of like kind feeding also by way of a NAND gate into a down counter. Both counters feed into an added which provides a signal to a decoder representing the phase difference between the input phase and the output phase signal. The phase processing system provides positive rapid pull-in over the entire frequency range capability of the VCO, which allows narrow bandwidth loops to track rapid rates of frequency change without loss of lock and with great accuracy.

Abstract: A device for compensating for gyro wheel frequency inaccuracies wherein a reference oscillator feeds a square wave signal to a first and second counter. The second counter also has an input of plus or minus the spin axis angular rate. The first counter scales down the reference signal and the second counter generates a signal having a frequency proportionately higher than the first counter. The output of the second counter provides a signal indicative of angular spin rate displaced from the input gyro axis. The outputs from the first and second counters are fed to an up/down counter which combines the two signals to provide for gyro wheel compensation.In a second embodiment of the invention a computer having spin rate axis signal from two gyros, control two settable counters to obtain compensation of the gyro wheel of a first and second gyro.

Abstract: A gyroscope which has a spinning fluid filled annulus as an inertial angle rate sensor is compensated for inertial drift by resolving an output signal from the sensor into acceleration proportional components related to the gimbal axes and the component related to the inner axis is applied to the outer axis, and the component related to the outer axis is applied to the inner axis to cancel out the effects of drift.