Abstract: The circuit uses a current sensing device that is controlled by the telephone line current. The telephone lines are connected to the contacts of a push-button switch, and a diode bridge is connected across contacts of the switch. Further, the circuit has a DC slow-release relay that is located across the output of the diode bridge. The telephone lines are also connected to the relay contacts of the DC slow release relay. A capacitor is placed across the telephone lines, and another capacitor is placed between the diode bridge and one of the relay contacts of the DC slow-release relay. The two capacitors act to shunt any radio frequencies that occur in the circuit as a result of an attempt to obtain information by RF saturation techniques.

Abstract: The Compression of Hyperdata with ORASIS Multisegment Pattern Sets, (CHOMPS), system is a collection of algorithms designed to optimize the efficiency of multi spectral data processing systems. The CHOMPS system employs two types of algorithms, Focus searching algorithms and Compression Packaging algorithms. The Focus algorithms employed by CHOMPS reduce the computational burden of the prescreening process by reducing the number of comparisons necessary to determine whether or not data is redundant, by selecting only those exemplars which are likely to result in the exclusion of the incoming sensor data for the prescreener comparisons. The Compression Packaging algorithms employed by CHOMPS, compress the volume of the data necessary to describe what the sensor samples. In the preferred embodiment these algorithms employ the Prescreener, the Demixer Pipeline and the Adaptive Learning Module Pipeline to construct a compressed data set.

Abstract: A mobile X-ray machine includes an improved Marx generator. The capacitors sed in the Marx generator are disc capacitors each having opposed side surfaces having electrodes formed thereon and each including a insulative coating provided on the peripheral edge thereof. The capacitors are mounted in slots in a support structure and are supported by spring contact members located within the slots. The spring contact members include spring arms which engage the electrodes on the opposed side surfaces of the associated capacitor. The spring contact members also include support elements from which are suspended the spherical electrodes of spark-gap switches individually associated with each of the capacitors.

Abstract: This invention describes a process for locating the position, orientation d depth of fiber optic sensors embedded in a composite material. The process encompasses the coating of the fiber optic sensor with an X-ray opaque material prior to embedding the sensor in a composite material and then mapping the composite material using radiographic techniques to accurately establish the location, orientation and depth of the sensor. A radiographic film or electronically recorded record of the exact placement of the sensors is prepared that may be referenced during machining operations, correlation of test results and accurate mapping of the structure.

Abstract: A method for producing divalent scandium includes heating, at a mildly elted temperature above 20.degree. C. under reduced pressure, a calcium difluoride crystal sample doped with scandium trifluoride to drive off atmospheric impurities, heating at an intermediate temperature above 150.degree. C. calcium metal under reduced pressure to drive off volatile impurities, heating calcium metal at a migrating below 900.degree. C. to evaporate calcium and to deposit it on the sample, and heating the sample at a diffusion and reaction temperature below 950.degree. C. to diffuse calcium into the sample and to cause formation of the divalent scandium.

Abstract: A secure communications system which comprises a laser-sending system and a light receiver. The laser light is divided into two beams, one beam is modulated to add the signal thereto, then the beams are recombined and directed to the receiver. The receiver then separates and demodulates the signal.

Abstract: This invention transforms a single sub-nanosecond event into a repetitive event, which then can be used as input to a conventional high bandwidth digital sampling oscilloscope by utilizing a delay line switched to form a closed loop provided with a gain. The single event, as a single pulse of a series of repetitive pulses, is allowed to enter and circulate around the loop where it is amplified and periodically read out to a readout device.

Abstract: The fiber-optic pipette (FOP) couples a glass capillary, common syringe and a single optical fiber together to provide for a facile means of achieving long-pathlength capillary spectroscopy. The FOP acquires rapid spectroscopic measurements of small-volume liquid samples, while simultaneously achieving signal enhancements of the collected spectroscopic signal.

Abstract: The stripline-slotline digital phase shifter is located between a ground plane associated with a patch antenna and another ground plane associated with the other patch antenna, or other output circuits. It is comprised of a section of stripline adjacent to a slot in ground plane associated with the receiving patch antenna which transitions an input electromagnetic signal to a plurality of oval slotlines, called bit circuits, of varying lengths which form a delay circuit by shifting the phase of the input electromagnetic signal. The varying lengths of slotline are switched into and out of the circuit to provide a predetermined amount of delay and the phase adjusted electromagnetic signal is transitioned to portion of stripline adjacent to a slot associated with the transmission patch antenna or other output circuits.

Abstract: A non-power generating current limiting device such as a field effect transistor is provided to output a regulated current in dependence upon a control voltage. An electron field emitter is connected to a drain or output of the non-power generating current limiting device to receive the regulated current. A tip of the electron field emitter emits electrons towards a collector anode. An extractor gate can be provided between the electron field emitter and the collector anode to control the rate of electron emission from the electron field emitter. Because the non-power generating current limiting device regulates the current to the electron field emitter, a maximum current output of the electron field emitter is limited to the regulated current from the voltage controlled current source. The electron field emitter is thus protected from destruction due to excess current. The non-power generating current limiting device can also be used to modulate electron emission from the field emitter.

Abstract: The orbit/covariance estimation and analysis (OCEAN) technique utilizes ground station observations collected from satellites passing overhead and estimates the positions, velocities, and other parameters of multiple satellites. It also estimates parameters for other elements, such as the locations of ground stations and measurement biases. The technique utilizes recorded observations (e.g., range, Doppler) and measurements from various sources as inputs to a weighted least squares batch estimation algorithm used in iterative fashion to estimate each parameter, with or without a priori knowledge of the errors involved with each observed parameter. The process is completed once the residual, the difference between the estimated parameter and the observed parameter, satisfies the tolerance defined by the user. Using the results of the estimation process or a predefined initial condition file, the OCEAN program can also generate a predicted trajectory (i.e.

Abstract: A forward-coupled array topology is used for a ladder-type fiber optic ser system in which each optical path in the system includes the same total number of input and output optical fiber sections and approximately the same total number of input and output couplers and splices so that the coupler splitting ratios for optimum optical performance are independent of light losses in the system.

Abstract: This invention is a quasi-static fiber pressure sensor using self-referenced interferometry based on a broadband semiconductor source which probes the pressure plate deflection within a Fabry-Perot cavity where phase is demodulated with a dual grating spectrometer providing real-time, high resolution remote measurement of pressure using optical interrogation of a deflecting pressure plate. This technique yields absolute gap measurement in real time over a wide range of gap lengths with nanometer resolution. By tailoring the pressure plate design to cover the range of gaps and deflection that can be resolved, pressure sensing with psi resolution can be obtained in a kpsig pressure range.

Abstract: The inflatable, non-collapsible, flotation device (INCFD) utilizes foam mng chemicals within a flotation chamber where the materials react and harden to form a layer of pliant foam, such as polyurethane. The foam, during reaction, conforms with the shape of the wearer and hardens to provide both flotation and physical protection from exterior objects.

Abstract: A field emission X-ray tube is provided for use in a mobile X-ray machine. n evacuated ceramic housing having a convoluted interior shape for dissipating sparks surrounds the components of the field emission tube. A cathode and, an anode which emits x-rays, are located within the ceramic housing. A hollow anode tube is connected to the anode at one end and a vacuum pinch off element at the other end. Stray radiation is attenuated by a lead ring positioned inside of the ceramic housing.

Abstract: The interferometric fiber optic accelerometer is viewed as a mass-spring nsducer housed in a sensor case. The sensor case is attached to a moving part whose motion is inferred from the relative motion between the mass and the sensor case. A flexural disk is housed in a sensor case which is accelerated in a direction normal to the plate surface. The plate undergoes displacement resulting in strains on the plate surface. A coil of optical fiber, made to be part of an optical interferometer, is attached to the flexural disk, the strain from the disk is transferred to the fiber thus changing the path length of the fiber interferometer. The interferometer output in demodulated providing the acceleration response. The design of the accelerometer housing is such that it is highly immune to extraneous signals, i.e., dynamic and hydrostatic pressure.

Abstract: The device for tensioning sheet material applies a tensioning force around he outer edge of a sheet material to prevent the sheet material from wrinkling. These devices are attached to a supporting member forming the outer frame of a structure upon which the sheet material is to be attached and consist of tape strips or wires attached to or free sliding along the support member, sheet material of a differing material wrapped around the support member and attached to the main sheet material, with or without holes or slots, and extensions of the main sheet material around the support member, with or without heat created depressions along the border to relieve tearing stresses. Another tensioning member is a corner brace between perpendicular segments of the supporting member to remove wrinkles caused by manufacturing irregularities.

Abstract: The broadband microwave frequency shifter is an electro-optical device that accomplishes frequency shifting, or translation by the use of serrodyning or mixing techniques. A first optical signal is modulated with the radio frequency signal desired to be translated and processed to produce an upconverted lower sideband optical signal. A second optical signal is frequency shifted using an optical phase shifter utilizing serrodyning techniques or by offset phase locking it to another optical signal. When the frequency shifted optical signal is combined with the upconverted optical signal and converted to an output radio frequency signal thereby producing an output microwave signal that duplicates the input microwave signal in all aspects except that its center frequency has been shifted.

Abstract: The extraction of phase information for radio frequency (RF) direction of rival is attained by pre-detect sensing and quantization of differential phase of a RF wave impinging on two or more antenna apertures, based on sensing and encoding differential phase without the use of conventional detection, and quantizing phase at or near the leading edge of a pulse signal. This is accomplished by detection of an intermediate frequency (IF) carrier, and encoding leading-edge phase (for each channel) in terms of near-phase-difference between two reference-oscillator readings containing the differential phase information--encoded as differential reference-oscillator phase. Precision angle-of-arrival is then derived from the measured differential reference-oscillator phase.

Abstract: The advanced vertical array beamformer signal processor accomplishes acoustic beamforming of an underwater vertical array used in shallow water utilizing matched beam processing to suppress generated noise and/or ship radiated noise thereby increasing the detectability of a submerged source emitting only a low noise signal. The processor exploits the difference of the signal arrival angle of both active and passive signals with that of the wind generated noise and ship radiated noise which is prominent in downward refractive sound speed profiles. After filtering the undesired noise, the processor uses the depth of the source as a clue for detection; the processor is an energy detector focused on the returns of a deep source.