Abstract: A digital data preprocessor is disclosed wherein consecutive samples of ny raw digital data telemetered from a dropsonde and decommutated are stored in a first storage stack of registers. Adjacent samples are subtracted, the adjacent first-differences therefrom are subtracted, and the resulting second-differences are stored in a second storage stack of registers. By a comparison of raw data with the second-differences, raw data distorted by noise are measured and subsequently restored to a new value calculated from valid values of raw data samples adjacent to the distorted value. The second-differences are fed through a series of adders to provide a sequence of second-sliding-sums which are stored in a third stack of storage registers. A significant value selector tests the sliding-sums using three different criteria. The results of the tests are used as a basis for selecting raw data samples from the stack for pre-output smoothing of the raw data.

Abstract: A harness system is disclosed for releasably restraining the torso of a cman in a seat aboard an aircraft. The harness system includes an upper torso restraint adapted to engage the seat at points on either side thereof and wherein a pair of chest straps connected to either side of a backpad are slidingly routed through respective roller fittings in a criss-cross fashion across the crewman to permit upper torso rotation. A separate lower torso restraint is coupled to the upper torso restraint and adapted to engage the seat at the same points of engagement as the upper torso restraint. A single-action release mechanism, actuated manually or automatically by water immersion, disengages both the upper and lower restraints from the seat thereby divesting the crewman of the harness system.

Abstract: A rubber-modified epoxy adhesive and the method of making the same is dissed for use in bonding graphite-epoxy composite structures. The adhesive comprises a two-part formulation, one part being a reaction product of a carboxyl terminated reactive liquid rubber prereacted with a bisphenol A epoxy resin so that linear epoxy-rubber chains are developed. The second part of the adhesive is an amine curing agent. One effective example of the adhesive is formulated as follows: approximately 4 parts by weight of the bisphenol A epoxy resin is mixed per part of a carboxyl terminated butadiene acrylonitrile rubber and heated to 170.degree. C. At 160.degree. C., a catalyst of approximately 0.01 parts by weight of triphenyl phosphene per part of the rubber is added and the mixture stirred for one hour at 170.degree.-175.degree. C. to provide the reaction product.

Abstract: An aircraft ejection seat is provided with deployable fins for stabilizing aw rotation. The fins are normally stowed along the sides of the ejection seat. During ejection, the fins are deployed aft of the seat by means of rotational actuators. Anti-entanglement sheets are collapsibly disposed between the fins and the sides of the seat in order to prevent fouling of the parachute.

Abstract: An electronic circuit provides short circuit protection and idle current control for a direct-coupled power amplifier.For short circuit protection, a voltage proportional to output current is monitored and is fed to a light emitting diode (LED). Light energy emitted from the LED as a function of output current is optically coupled to a phototransistor which steals drive current from the input transistor of the output amplifier hence turning off the output transistor.For automatic idling current control, the idle current of a complementary output transistor pair is sampled by operational amplifiers each having an inhibit gate connected from the output of a respective comparator. The comparator produces an inhibit output when the output transistor pair is providing load current to the load. When the pair is not providing load current, the amplifier amplifies the idling current from the pair and provides it to an LED.

Abstract: A transducer is provided having interconnections between a conductive member and one side of a heat sensitive piezoelectric substrate such as PVF.sub.2 to or from which electric signals flow. The interconnections are positioned on one side of the substrate with the opposite side having a metalization under the interconnection attachment positions and in a continuous region therebetween. The interconnection includes adhesive material such as epoxy disposed between and attaching an electrically conductive member to one side of the substrate and a single contiguous electrically conductive coating applied to adjacent portions of these two members to electrically connect them. Since both interconnections are positioned on one side of the substrate the transducer is adhesively fastenable to operational structure with a strong bond line, permits lead attachment after mounting and prevents lead shortout.

Abstract: An optical system is disclosed wherein light is transmitted through fibertic members orthogonally configured in a triaxial arrangement for measuring the magnetic field vector preset in the environment. In one preferred embodiment, a set of three fiber-optic coils positioned coaxially along respective orthogonal axes and having predetermined lengths and diameters are coupled to a source of polarized light for transmitting the light subject to Faraday rotation of its plane of polarization. In another preferred embodiment, light, not necessarily polarized. is transmitted along respective orthogonal axes through a set of three bifurcated fiber-optic cables each formed having a reference branch and a substantially equilaterally sensor branch on which a magnetostrictive material is intimately connected to produce optical path length changes related to the magnetic field component along the respective axes.

Abstract: A gated fiber optic sensor system is disclosed for increasing the effective ptical path of a length of optical fiber cable. A pulse of polarized light having a known optical wavelength is directed into a length of optical fiber cable for propagation therethrough in a cyclic path. A planar semiconductor member is mounted in the path of the polarized light pulse at the Brewster angle to permit continuous transmission of the polarized light pulse through the cable until a light pulse of a second optical wavelength is made to impinge upon the semiconductor member, changing the reflectivity characteristics thereof and causing the polarized pulse to be extracted from its cyclic path for detection and processing.

Abstract: A pneumatic launch system for an aircraft for ejecting one at a time a pllity of sonobuoys within each of a multiple array of tubes. A compressed air supply from the aircraft is regulated in a plenum selectively having poppet valves for selectively releasing plenum air to each sonobuoy within a tube. Each poppet valve is held against the outlet port by differential gas pressure across a piston connected to the valve. A quick exhaust valve bleeds the air from one side of the piston causing it to open and allow the plenum air to pass through the port and apply an ejection force to a sonobuoy. When the exhaust valve is closed, the pressure on either side of the piston equalizes and the poppet valve closes. A replenishment poppet valve recharges the plenum when the pressure drops below a regulated level.

Abstract: An improved system is disclosed for calibrating acoustic pressure-sensitive transducers, particularly hydrophones, down to frequencies in the sub-Hertz range. A transducer under test and a reference transducer, both electrically connected to a voltage measuring device, are mounted in aligned proximity to each other upon a pivotal rocker arm immersed in a water tank. A cam and follower unit driven by a motor oscillates the rocker arm so that the transducers are moved through a vertical displacement equivalent to the desired fluctuation of hydrostatic pressure. As a result, calibrations down to 0.01 Hz are achieved.

Abstract: An aircraft ejection seat position and restraint system for protecting an rcrewman against back injuries during emergency escape. The ejection sequence is initiated by the aircrewman pulling a lower ejection handle or a face curtain handle with both hands to release or shatter the cockpit canopy. A torso harness suit is concommittantly tightened with inflation of a vest worn between the aircrewman and the suit, and catapult rockets are fired to propel the seat out of the cockpit. The harness suit draws the aircrewman's upper torso against the back of the seat while the inflated vest pushes his hips back and down into the seat pan for optimally positioning his spine before ejection thereby negating the effects of an aircrewman purposely or inadvertently flying with a loose harness. After ejection, the seat is separated from the aircrewman but the vest remains inflated inside the harness providing cushioning against the opening shock force of the parachute which is attached to the harness suit.

Abstract: An interferometrically tuned laser resonator for selectively resonating at desired wavelength or fluorescent line. A dielectric reflector having reflectance characteristics which shift toward shorter wavelengths at incident angles not normal thereto is rotatably mounted at one end of a laser cavity along its axis. Rotation of the reflector permits adjustment of the incidence angle to obtain maximum cavity gain at a desired fluorescent line over adjacent competing lines.

Abstract: An acoustic telemetry system and technique are disclosed for remotely meaing the underwater depth and descent rate of a hydrographic package. Analog signals indicative of hydrostatic pressure exerted on the package and related to its underwater depth are periodically sampled and converted to an N-bit digital word representative of the value of pressure. Each bit of the digital word operates one of a plurality of tone generators of different acoustic frequencies in a narrow band, and the outputs of the tone generators are combined with a reference tone continuously generated to permit resolution of Doppler shifts. Acoustically projected through the water to a remote hydrophone, a composite signal representative of the combined tones is corrected for Doppler shifts by translating the frequency of the signal in accordance with shifts detected in the reference tone.

Abstract: A self-retaining locking assembly for threaded couplings. An externally threaded bolt rod end bearing is threadedly secured to a nut or internally threaded piston rod. The bearing includes an axially extending keyway along the threads, and the piston rod includes a circumferential groove at the mating end as well as radially extending slots in the mating face. An annular lock member has a lug projecting radially inwardly of the central aperture for engaging the keyway, and ribs and clips for mating with the radial slots and annular groove, respectively, when the rod is threaded upon the bearing. The lock member therefore cannot rotate relative to the bearing, and the piston rod cannot rotate relative to the lock member whereby the entire assembly is secured together in fixed relationship.

Abstract: A system for evaluating tolerance to high acceleration as a function of visual field perimeter and psychomotor tracking ability. A semicircular array of light-emitting diodes (LED's) subtend the lateral field of view of a subject. Pairs of opposed LED's are sequentially illuminated inwardly or outwardly at a programmed rate. A control stick manipulated by the subject provides a nulling signal for maintaining a desired pair of LED's illuminated.

Abstract: An electro-optical display system, particularly useful aboard aircraft carriers, is disclosed for remotely aiding a pilot in the landing of an aircraft. A conventional radar receiver continuously tracks the aircraft and produces a digital data signal indicative of aircraft slant range and elevation angle. The digital data signal is provided to a signal processor governed in accordance with either of a pair of control guidance algorithms to produce a control signal indicative of the magnitude and direction of an error in the appropriate descent rate of the aircraft. Based upon the control signal, a display driver produces a plurality of drive signals for energizing discrete light cells in vertically-oriented arrays as a visual indication of the descent rate error for appropriate corrective action by the pilot.

Abstract: A compact and modularized boiler is comprised of interconnected modules. h module is removable and replaceable with an identical module for easy on site repair. The modules are separated physically and in function as a supercharger module connected to provide compressed air; a burner module connected to receive fuel and compressed air for combustion; a furnace module housing a combustion chamber for receiving hot gas from the burner module and water to be heated from a pump module; a steam drum module for separating liquid and steam; a superheater module interfaced with the furnace module for generating superheated steam; and a convection module for providing additional surface area for heat transfer from the hot gas to the working liquid. The boiler is compact and modular.

Abstract: A laser device for generating frequency-doubled laser pulses at maximum eciency. A laser rod is optically pumped to radiate unpolarized light at 1.064.mu. wavelength for transmission within a ring-type resonator defined by a flat mirror and a turning prism. The light from one end of the rod is linearly polarized by a beam splitter into two parallel beams of orthogonal components which are transmitted through an 0.532.mu. output mirror, a frequency doubler phase matched for one component, and a Q-switch, to the turning prism for return along the beam of the other component to the beamsplitter. The output mirror, doubler and Q-switch are substantially ineffective during the pumping cycle, and because the component beam axes are reversed, the light does not return to the rod for stimulating light emission. After peak level pumping, however, the Q-switch is biased to rotate each component one quarter wavelength and return the components to combine and reenter the rod for stimulated light emission.

Abstract: A signal processing system and technique is disclosed for detecting the pence of a desired frequency signal particularly that of a sine wave, in a noisy environment. The signal mixed with noise is received and analyzed by a Fast Fourier Transform spectrum analyzer the output of which is indicative of instantaneous signal phase. The output of the spectrum analyzer is digitally processed to produce a series of average instantaneous signal values based upon the instantaneous signal phase and a statistical estimate of its rate of change, the values being representative of the relative signal strengths for a progression of phase reference values between 0.degree. and 360.degree.. The desired signal is detected when an average instantaneous signal value exceeds a threshold value determined empirically based upon a certain probability of detection and false alarm rate.

Abstract: A mechanical and electrical connection for a piezoelectric member of polyic material such as polyvinylidene fluoride, and method for forming such a connection. To form the connection, the piezoelectric member is first masked to prevent a preselected portion of its surface from being coated during subsequent coating operations. An electrically conductive member such as a lead wire or a solderable terminal is then attached to the nonmasked area of the piezoelectric member with adhesive such as epoxy. The masked piezoelectric member, the electrically conductive member, and (incidentally) the mask are then coated with a conductive coating such as sputtered gold to electrically connect the conductive member to the piezoelectric member. The mask can now be removed from the piezoelectric member if desired, although it can be left in place as a convenient vise.