Abstract: A method and apparatus for zero fringe shift referencing has unique appliion in an optical fiber interferometer gyroscope. Passive optical couplers introduce pulsed laser energy into the interferometer's main loop and a much smaller loop encircling a negligible area. An output signal from the smaller loop is representative of a zero rotation rate while the output signal from the much larger main interferometer loop is representative of an unknown rotation rate. The zero rotation rate and unknown rotation rate signals are compared and referenced so that there can be compensation for the response variation of the photodetectors or the source of laser energy to enable more accurate responsive readouts.

Abstract: A transform system provides a real-time implementation of the discrete Foer transform (DFT) of length N, the system being useful in sonar and radar signal processing. The input signal g.sub.n, 0.ltoreq.n.ltoreq.N-1, comprises a discrete signal, generally complex, of N samples.The system comprises an input for receiving the input signal g.sub.n and convolving in a first, input, convolver with a signal represented by the function e.sup.i.pi.n.spsp.2.sup./N , to result in a first modified signal at the output of the first convolver. Means are provided for generating the signal e.sup.-i.pi.n.spsp.2.sup./N. A multiplier receives the first modified signal and the signal e.sup.-i.pi.n.spsp.2.sup./N and multiplies these two signals its output being a second modified signal.A second, output, convolver, whose input is connected to the output of the multiplier, convolves the output signal from the multiplier with a signal represented by the function e.sup.i.pi.n.spsp.2.sup.

Abstract: A semiconductor laser alignment device for aiming a laser light beam, broast by a weapon, along an optical light path such that the laser light beam is in alignment with the aiming direction of the weapon at a target which is located a predetermined distance from the weapon. The semiconductor laser alignment device comprises a tubular housing attached to the barrel of the weapon, a laser diode located within the tubular housing for broadcasting the laser light beam, and a projecting lens for collimating the laser light beam broadcast by the laser diode. Zeroing means connected to the laser diode positions the laser diode such that the laser light beam broadcast by the laser diode is in alignment with the line of sight of the weapon.

Abstract: Apparatus and method for separating and removing oil and particulate solids from a dispersion of oil and particulate solids in water or a water-based liquid. During separation, the dispersion is fed under pressure into the inlet end of a plurality of upright coalescer tubes made of a single-layer of flexible, water-permeable fabric and is prevented from exiting through the outlet end of the tubes. The water passes radially through the fabric walls into a stilling chamber surrounding the coalescer tubes and exits through a clean water outlet while the solid particulates are retained on the inner surface of the fabric. The oil particles coalesce on the inner surface of the tubes, forming a layer of oil which migrates through the fabric's pores due to the pressure differential between the inner and outer tube surfaces and forms an oil layer on the outer surface of the fabric.

Abstract: A system for operating a lifting cable over the side of a ship at sea in ch a spar buoy having an adjustable lifting capacity is coupled to the ship by a rigid linkage which is free to pivot on an axis attached to the deck. The lifting cable is suspended from a first sheave which is mounted above a central, longitudinal channel in the spar buoy. The linkage is attached to the top of the spar buoy such that the spar buoy may rotate about an axis normal to the deck axis of the linkage and pivot on an axis normal to the longitudinal axis of the spar buoy. A second sheave is mounted on the deck axis so that the distance between the sheaves does not change as the linkage rotates on its axis. The lifting cable is fed from a winch on the ship over the sheaves and falls through the longitudinal channel. The invention operates to decouple the motion of the ship from the lifting cable so that the vertical motion of the cable is controlled by the motion of the spar buoy.

Abstract: A multilayer printed circuit board is disclosed having appropriate ground and voltage planes. The multilayer printed circuit board includes a mounting plane, a plurality of dielectric sheets stacked upon the mounting plane, a plurality of conductive sheets positioned between adjacent dielectric sheets, and a plurality of rectangular shaped apertures passing through the multilayer printed circuit board. Each rectangular shaped aperture of the multilayer printed circuit board has a plurality of voltage connector terminals. Electrical connection from one of the conductive sheets to the appropriate voltage connector terminal is provided by a conductive disc which passes through a hole located within the multilayer printed circuit board.

Abstract: An etched plate used to simulate an infrared target for trainees using siated weapons. Selectively etching the plate in a variety of fashions successfully imitates the thermal signature of the simulated target. The simulated weapons are then "fired" at the plate and hits recorded. The plate may be electrically heated.

Abstract: A temperature and moisture regulator for such devices as integrated circuits and the like is disclosed as comprising an insulated mount for the device whose temperature and moisture is to be regulated, a first thermoelectric cooler in effective contact with both a certain substantially central area of said device and one end of an elongated metal heat-sink. A plurality of resilient heat-conductive, thermal feedback fingers are metallurgically bonded at one of the ends thereof to said heat-sink and are urged against a portion of the surface areas of said device at the other ends thereof in predetermined spatial dispositions from but in proximity with the aforesaid central area thereof that is in contact with said first thermoelectric cooler. Hence, both cooled and heated areas occur on various surfaces of said device, the former of which effects the cooling thereof, and the latter of which effects the heating thereof and, thus, the controlling of whatever moisture is caused by the cooling thereof.

Abstract: Apparatus for electrically isolating a DC voltage source while the voltage f the source is being measured or otherwise monitored. An electronic switch is provided for selectively coupling the apparatus to the source, and a first optical device coupled to the switch receives a control signal which directs switch operation. The first optical device electrically isolates the switch from electrical equipment which generates the control signal. A device for generating an internal voltage data signal is also coupled to the switch, the frequency of such signal varying according to the voltage of the source. A second optical device receives the internal data signal, and couples an external data signal to voltage monitoring equipment, the external data signal having a frequency which varies according to the frequency of the internal data signal, the second optical device electrically isolating the switch from the voltage monitoring equipment.

Abstract: A pipe-coupling assembly includes a radially-extending ring-shaped member rrying a flow-controlling valve plate. Ring-supporting members press flushly against both sides to operatively mount the ring member and its valve plate in the conduit. Non-reversibility is achieved by forming a lateral flange on one side only of the ring member and a mating groove in one only of its support members. Correct mounting requires the mating of the flange and groove.

Abstract: A separable connector is provided for optically joining one or more pairs of fiber optic cable terminals, each of which pairs is supported within a respective rigid alignment sleeve mounted within the connector in a resilient collar so that the alignment sleeves can be individually longitudinal withdrawn from the collar to allow cleaning of the cable faces; the terminal ends of each pair of cables being maintained in a closely spaced, single air-to-glass optical junction.

Abstract: An apparatus and method are provided for depositing submicron patterns on a substrate. The apparatus includes an evaporative source located opposite the substrate so that molecules from the source can be deposited directly on the substrate. A mask is located between the evaporative source and the substrate, the mask having openings which correspond to the desired pattern to be deposited on the substrate. A plate is located between the mask and the substrate, the plate having an aperture for allowing evaporated molecules to be deposited on the substrate according to the pattern of the mask.

Abstract: A system for battlefield and enemy support area surveillance. An air-drop unit monitors and records on tape enemy activity, and plays back and transmits the monitored data at high speed when interrogated by a coded signal from friendly aircraft.

Abstract: A device for comparing the frequency of the output signals of a plurality electronic clocks such as cesium beam time and frequency standards. A plurality of circular shift registers are loaded with identical binary patterns which are circularly clocked through the shift registers by the electronic clocks under test. Logic gates at the outputs of the circular shift registers detect the coincidence of the bit patterns during preselected intervals. As long as the outputs of these logic gates indicate a coincidence during the preselected interval, a holdover multivibrator at the output of each logic gate holds its output at a predetermined level. If a coincidence does not occur during the predetermined interval thereby indicating an error in one of the electronic clocks, the associated holdover multivibrator will change its output condition. This change in output condition of the holdover multivibrator results in the switching of a switching network connected at the output of each holdover multivibrator.

Abstract: A transducer array release and pressure compensation system for releasing a ose cone assembly from a cylindrical housing so as to deploy a plurality of transducer elements and pressure compensate the transducer elements. When hydrostatic pressure is applied to a bladder located within the nose cone assembly, the bladder pulls a release cable so as to release a split ring which secures the nose cone assembly to the cylindrical housing. The application of hydrostatic pressure to the bladder forces air from the nose cone assembly through a compensator airline to the transducer elements so as to pressure compensate the transducer elements.

Abstract: Apparatus for use as a chain climbing device or a chain racheting device ludes a pair of spring-closed opposing cams disposed in a rigid structure which supports a pair of cam pins, each of which extends through an elongated aperture in one of the cams. The weight of a person using the chain climbing device is transferred from a pair of cam stops attached to the rigid structure to the cams to the chain. When the device is used for chain racheting the weight of the chain is transferred to the cams to the cam stops to the rigid structure. The shape of the cams and the elongated apertures enable the cams to rotate about and slide upward or downward on the cam pins to selectively allow upward or downward relative motion between the chain and the apparatus or lock the chain and the apparatus in a fixed relationship.

Abstract: A parallel digital beam-former for an array of hydrophones. The output of ch hydrophone is fed into a different shift register. Each register stores the sampled time history of the hydrophone. The contents of each register are fed serially into a different gating circuit in the time interval between each new input signal sample and the output of each gating circuit is fed in parallel with the output of each of the other gating circuits to a group of beam gates. The output of each beam gate is then fed to a different binary counter which sums the signals. Each binary counter is associated with a different beam.

Abstract: A system and method for providing substantially constant visibility over a ask area within a work area with time in which the visibility provided by natural daylight illumination is supplemented by a variable artificial illumination from luminaires to maintain a specified visibility. The background luminance and the difference luminance are determined as a function of the artificial illumination and the natural daylight. These relationships are used to determine the actual visibility at the task. The actual visibility is then compared with a criterion visibility and the intensity of the artificial illumination from the luminaires is varied to bring the actual visibility to the criterion visibility.

Abstract: A synthesized sinusoid generator for delivering to an acoustic driver high ower of a discrete spectral component from a spectrum including the discrete spectral component and its harmonics. The generator uses a plurality of unity gain switching amplifiers and involves summing various stages thereof at full power. This is accomplished by switching on and off various unity gain switching amplifiers as a function of time of the fundamental, thus necessitating only generation of the fundamental frequency and a delay network to switch on and off the designated unity gain switching amplifiers.

Abstract: A method of fabricating light emitting diodes to prevent degradation caused y thermally induced stress. A voltage is applied across the chip to cause it to bend to a prestressed condition while it is being soldered to the header. The biasing voltage applied is continued until after the heat is removed and the solder cooled leaving the diode in the prestressed condition.