Abstract: A method and system for determining the geolocation--i.e., the latitude, longitude, and altitude--of a stationary RF signal emitter from two or more moving observer aircraft. The observers receive signals from the emitter and the system measures the phase difference between the signals. The observers then perform pulse time of arrival (TOA) measurements over a predetermined clock interval, and calculate the time difference of arrival (TDOA) of corresponding, same-pulse, emitter signals. Based on geometric relationships, the system creates a series of circular lines of position (LOPs) for each observer, and computes hyperbolic LOPs based on the TDOA calculations. The system determines emitter location from the intersection of the hyperbolic LOPs and the circular LOPs.

Abstract: An electrical cable connector is disclosed for connecting a plurality of electrical conductors to a printed circuit board. The cable connector includes a cable socket connector having a plurality of female insulation displacement contacts which can be mated with male signal-carrying pins contained in a pin shroud on a printed circuit board. The cable socket connector is comprised of a hood which retains two or more wafers. Each wafer contains a plurality of insulation displacement contacts. The cable socket connector may include a latch for securing the cable socket connector to the pin shroud and shielding to prevent extraneous signals from being transmitted into the circuits on the printed circuit board through the cable connector. The cable connector also includes an arrangement for keying the cable socket connector to the pin shroud to control the location of insertion of the cable socket connector into the pin shroud.

Abstract: The reservoir system includes a heater coil having electrical leads adapted to be coupled to a voltage source. The heater coil is adapted to generate heat in correspondence with a heater voltage provided by the voltage source. A reservoir material layer is adapted to regulate pressure of a gas disposed within the gaseous-discharge device in accordance with temperature of the reservoir material. Heat is transferred from the heater coil to the reservoir material through a series of thermally conductive layers in which each of the layers have different thermal conductivity and coefficients of expansion. As a result, the thermal path resistance between the heater coil and the reservoir material layer increases as temperature of the heater coil increases so that the reservoir material increases in temperature at a slower rate than the heater coil.

Abstract: The invention is a method for obtaining a measure of the light propagation time difference for two light-propagating-media paths. The first step consists of generating two substantially-identical frequency-modulated light waves whereby the frequency of the light waves is offset from a reference frequency by a different frequency increment for each basic time interval in each of a plurality of groups of three or more basic time intervals. Each frequency increment is the sum of a specified increment and a frequency-modulation-error increment. The frequency-modulation-error increments associated with the specified increments are independent of each other and unknown. The second step consists of feeding the two light waves into the entry points of two light-propagating-media paths having a light propagation time difference and obtaining a combination light wave by summing the light waves emerging from the exit points of the two light-propagating-media paths.

Abstract: An autostereo projection system uses multiple projectors to form a seamless and extended field of view. Each projector is registered to a CRT display. Shutter elements in each projector create multiple pupils for each CRT display. Each CRT display is driven with different images for each shutter pupil.

Abstract: An angular rate sensor provides a digital delta theta output signal. A drive member is formed of a single, silicon wafer having a pair of oppositely-facing planar surfaces. The drive member includes a frame and a drive member central portion connected to the frame and arranged to have rotational compliance between the frame and the central portion about an axis perpendicular to the planar surfaces of the silicon wafer. Drive signals are applied to a plurality of electrodes on the central portion to cause rotational oscillation of the drive member central portion about a drive axis perpendicular to the planar surfaces of the silicon wafer. A silicon sensing member is connected to the drive member. The sensing member has a central support member connected to the drive member central portion such that rotational oscillations of the drive member central portion are transmitted to the sensing member central portion.

Abstract: A grid support structure is provided for a linear beam device having an axially centered cathode, an anode spaced therefrom and a grid disposed between the cathode and anode. The grid support structure maintains a proper grid-to-cathode spacing across an operating temperature range of the linear beam device. The grid is comprised of pyrolytic graphite, and includes a central active portion and a peripheral portion, with the peripheral portion comprising a plurality of evenly spaced elongated mounting holes. The grid support structure includes an inner grid support and an outer grid support. The inner grid support may include a plurality of axially extending posts that engage the mounting holes of the grid. The grid may further include resilient tabs that engage corresponding ramped surfaces to bias the grid into position.

Abstract: A ceramic element is provided which can be injection molded from an electrolyte and a binder. The ceramic element includes a tube support portion and a plurality of tubes extending from the tube support portion. The plurality of tubes are arranged in rows and columns. A plurality of vias extend from one surface of the tube support portion to an opposite surface of the tube support portion. The ceramic element is coated with an electrically conductive coating and a current collector coating. The vias are coated with the electrically conductive coating and plugged. After the coatings are removed in selected areas of the ceramic element, the tubes of the ceramic element form a series-parallel array because tubes in the same column are connected in parallel electrically and tubes in adjacent rows are connected in series electrically. Two ceramic elements are sealed together to form a modular electrochemical device. The electrochemical device can be either an oxygen generator or a fuel cell.

Abstract: In a vibrating rotation sensor of the hemispherical resonator gyro type (HRG), operating in the whole angle mode wherein the standing-wave components are measured to provide a measure of the pattern angle, the digital signal processor functions to control the digital to analog converter output signal in order to keep the highly amplified analog to digital input signal, the difference between the pattern angle and excitation angle, within the analog to digital converter window. The analog to digital converter window is set at n times the discrete level of the digital to analog converter. A digital feedback loop in the digital signal processor continually corrects the tracking angle to control the excitation voltage.

Abstract: A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.

Abstract: Light emitting devices are combined with non-imaging optical elements to create a backlighting system for liquid-crystal displays (LCDs). A pair of optically isolated sub-systems, or sections a night vision imaging system (NVIS) (14) and a daylight system (12) are combined to provide optimum display legibility in ambient illuminations ranging from bright sunlight to total darkness. The sub-systems utilize non-imaging optics based upon total internal reflection (TIR) and light reflection, both coupled to a light emitting source, such as fluorescent tubes (34) and other linearly shaped light sources. Light reflectors (32) are shaped to concentrate light onto non-imaging optics lens (30) so as to compensate for non-linear characteristics of the TIR lenses.

Abstract: A method and various structures are described for reducing excess photon noise in short coherence light sources, such as broadband superfluorescent fiber or superluminescent diodes, for example. The method contemplates splitting the light source signal into a plurality of components, thereby splitting, and reducing, the photon noise or "beat noise" as well as the light intensity. Each component travels in a separate path having a unique time delay which is longer than the coherence time of the light source. The light from each separate path is recombined at an output end, prior to detection, causing the signal to get back to its original intensity, while keeping the total beat noise at a reduced level. The paths may be created using different length polarization maintaining (PM) fibers, different length optical fibers, or multi-mode fibers having several propagation modes propagating at different rates.

Abstract: A novel photocathode and image intensifier tube include an active layer comprised substantially of amorphic diamond-like carbon, diamond, or a combination of both. The photocathode has a face plate coupled to an active layer. The active layer is operable to emit electrons in response to photons striking the face plate.

Abstract: An improved dressing for the fiber optic leads of a fiber optic gyroscope sensing coil and method for forming the same. A pair of fiber optic leads connect the sensing coil of a rotation sensing device to an integrated optics chip. The fiber optic leads are originally arranged to extend around the fiber optic sensing coil in different directions. The leads are formed of unequal lengths, where the longer of the leads is extended along an outer circumference of the sensing coil. The longer lead is bent so that the circumferential direction of longer lead reverses itself, and the longer lead then extends around the sensing coil in the same direction as the shorter lead. A low modulus adhesive is applied to the leads and cured to initially bond the leads in place against the sensing coil. The pair of leads are then wound in the same circumferential direction adjacent to each other fashion around the outer circumference of the sensing coil.

Abstract: A multi-function day/night observation, ranging, and sighting device with active acquisition of optical targets includes a single objective lens and a single eyepiece lens and provides an image of a scene. The single objective lens leads to a visible-light first optical path and to an invisible-light second optical path. The invisible-light second optical path includes an image intensifier tube providing a visible image. The first and second optical paths converge with visible images provided by each pathway being overlaid at a reticule plane. A single light path leads from the reticule plane to the eyepiece lens. A laser provides pulses of laser light projected into the scene via the single objective lens, and the image intensifier tube is used as a detector for a portion of the laser light pulses reflected from an object in the scene in order to provide both a laser range finding function and an active optical target acquisition mode.

Abstract: Attenuation of an optical signal at the end of an optical fiber is achieved by positioning a high absorption region at the end of the fiber. A first embodiment teaches highly doped wedges within a tapered end of the fiber. The highly doped wedges adjacent the light transmitting core serve to absorb light at the end of the fiber. The light transmitting core of the fiber is reduced in diameter due to the tapering, causing the field of light to expand beyond the core. The highly doped wedges are in proximity to the core due to the tapering. The wedges, which are preferably heavily doped with a rare earth such as erbium, absorbs the escaping light in sufficient quantities, both in the initial pass through the tapered region and again upon reflection of the light at the end of the tapered region, such that the attenuation of the reflected light is within acceptable limits without regard to the condition of the fiber's end surface.

Abstract: The invention is a method for improving the performance of a fiber-optic gyro comprising counter-propagating light beams from a broadband source in an optical fiber configured as a coil. The fiber-optic gyro is of the type where the phases of the light beams are step-modulated at one or both ends of the optical fiber at time intervals equal to the light propagation time .tau. through the optical fiber, the step being in the range from 0 to 2.pi.-.delta. radians where .delta. is an infinitesimal. The step is the sum of an estimate of the Sagnac phase residual .phi..sub.SE with reversed sign and the quantity (2.pi.k+j.phi..sub.M) where the index k can take on the values -1, 0, and 1, and the index j can take on the values -1 and 1. The phase angle .phi..sub.M is a positive constant less than .pi. radians. The method comprises the steps of determining the interferometer output light intensity, determining the Sagnac fringe number n, calculating the error P.sub.

Abstract: A technique for interrogation of fiber optic interferometric sensors wherein an optical signal is modulated by an array of fiber optic sensors in response to acoustic pressure. Modulated signals (channels) from each sensor are multiplexed onto a single fiber optic cable and the multiplexed signal is input to a polarization diversity detector having at least two outputs. The optical signal is converted into a digital, electrical signal. A plurality of digital down converters demultiplex and demodulate the separate channels and output in-phase data and quadrature phase data for each of the signal channels. A system controller connects to the digital down converters and to a calibration digital down converter. The calibration digital down converter, controlled by the system controller, mimics an operation of each digital down converter in turn in order to determine optimal digital down converter settings for each digital down converter.

Abstract: An iris recognition apparatus (12a) and method includes a camera (22) for imaging the human retina as seen through the pupil. The reflective retina and pupil are imaged as a luminous or retro-reflective spot located in a field of view (26). A direction to the spot (i.e., the retina spot at the pupil within the iris) in the field of view is determined, and a fine-focus video camera (48) is directed along this direction to capture an image of the iris surrounding the pupil of the eye. The captured iris image can be used for unique and individual identification of the human whose eye is imaged using known data storage, retrieval, and comparison methods.

Abstract: The present invention is a method and apparatus for automatically placing a first unknown image, such as an unknown fingerprint image, into one of a plurality of categories. The invention includes storing in a library a plurality of value series, each of which series is derived from the frequency representation of an image category. The categorization process and apparatus takes the frequency image of a first unknown pattern to create a first frequency image. The frequency image plane of the first (unknown) frequency image is divided into a plurality of frequency image plane regions. Each of the frequency image plane regions may be an angular segment radiating from the origin of the frequency image plane. A region value is assigned to each of the frequency image plane regions based on the total energy in the frequency image in that region. The region values for the first frequency image are combined to generate a first series of region values.