Abstract: An attitude determination system uses multiple antenna inputs which are time-multiplexed into a multi-channel receiver. Each channel tracks one incoming signal from a known or ascertainable source. For each of the incoming signals being tracked, digital processing can be used to determine range differences between the different antenna elements for that incoming signal, and to compute attitude based on the range differences and the known configuration of the attenna elements relative to each other.

Abstract: A system and technique for controlling LCDs based upon measurement of optical response is disclosed, which includes a light source and a light detector on opposite sides of an independently driven test area of a LCD panel. A determination of the optical response time is made by comparing the varying signals from the LCD drive and the response detector and then changing the operation of the LCD panel or heater based upon the comparison.

Abstract: High strength gold wire for use in microelectronics and a method of producing the same are disclosed. In the methods of the present invention, a gold alloy having gold and a dilute rare earth (RE) element is produced. Next, the gold alloy is atomized into a powder. The dilute RE element is at least partially oxidized during atomization. Then, the powder is consolidated into an oxide dispersion strengthened gold billet. Finally, gold wire is formed from the oxide dispersion strengthened gold billet. The high strength gold wire can be drawn to a diameter less than conventional gold wire, while still maintaining mechanical and electrical properties, thereby facilitating microelectronics miniaturization.

Abstract: The inventive method calculates the column coefficients for a liquid crystal display panel. By using this method, the invention shows that the select/nonselect ratio can be maximized by the following ways: (1) Scaling the image to the maximally physically realizable select/nonselect ration via the following equation ##EQU1## (2) Choosing an optimum value for row rms voltage "F", (3) Altering the statistics of an image, to reduce the variance of the different columns and/or increase the average of the columns, (4) Altering an image through fastest ascent or minimal error methods and (5) Designing the image to be predominantly at high rms voltage states. The select/nonselect ratio determines the available voltage range to achieve gray scale or variation in intensity. By maximizing the select/nonselect ratio, the present invention is able to obtain a wider range of intensity variation, i.e. larger contrast ratio.

Abstract: An active matrix liquid crystal display (AMLCD) system is for use in avionic applications. The system includes an integral cathode fall indicator. The indicator relies on a gas fill mixture to provide an orange glow when the cathode fall region has an abnormally high potential across it. During normal operation, the gas fill mixture provides a light blue glow. The gas mixture includes helium, neon, argon, krypton, and xenon.

Abstract: A system and method of processing wireless signal of data pulses or packets in a communicator system, in which a coded signal is received, synchronized and a histogram of signal parameters is constructed within the receiver at regular intervals. The date in the histogram is then compared to expected values for e given parameter and an appropriate correction factor is generated and utilized in subsequent signal synchronization.

Abstract: A method and apparatus for determining and removing the error in the SPS measurement of the Global Positioning System due to ionospheric delay. The disclosed technique utilizes semi-codeless technique to provide high accuracy GPS measurements. The delay of the P code is varied and the signals are cross correlated until a maximum value is reached. When the cross correlation of the L1 and L2 signals is at a peak value, the relative delay between the L1 and L2 signals is proportional to the ionospheric delay. The derived ionospheric delay may be accounted for in measurement analysis of the L1 signal to provide for a high precision position solution. The semi-codeless correlator also provides the L1-L2 carrier phase measurement for wide-lane applications.

Abstract: A phase-locked loop frequency synthesizer system is provided using fractional frequency division and a fractional control number for phase modulating an output of the frequency synthesizer using an incoming information signal. The apparatus includes a delta-sigma converter which adjusts a divisor of the frequency divider by operating upon a magnitude modulated fractional frequency control number. The system further includes a differentiator which provides the magnitude modulated input stream to the delta-sigma modulator by modulating the fractional control number with detected differences in the incoming information signal.

Abstract: An electrochemical device includes a transparent first electrode and a second electrode distributed in localized areas. An electrolytic solution, disposed between and in electrical contact with the first and second electrodes, contains ions of a metal which can electrodeposit on the first and second electrodes. Atoms of this metal are deposited on the first or the second electrode. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode, thereby affecting the propagation of electromagnetic radiation through the device. Conversely, a positive electrical potential applied to the first electrode causes deposited metal to be dissolved from the first electrode and electrodeposited from the solution onto the second electrode, thereby increasing the transmissivity of the device.

Abstract: A non-emissive display unit such as a liquid crystal display is disclosed. The non-emissive display unit is adapted for mounting in a rack or panel. The non-emissive display unit includes a display cabinet and a non-emissive display device which is coupled to the display cabinet such that insertion of the display cabinet into the rack or panel mechanically and/or electrically couples the non-emissive display device to the rack or panel. The non-emissive display unit also includes a light source mounted to the rack or panel adjacent the display cabinet such that the light source can be removed and replaced from the rack or panel without decoupling or removing the non-emissive display device from the display cabinet. Insertion of the display cabinet into the rack or panel optically couples the display device inside the cabinet to the light source mounted to the rack or panel.

Abstract: A system for coupling circuit card assemblies or modules that comprise a given device, that accommodates manufacturing and design differences in connector configurations. A common back-plane having one or more signal buses is joined to the circuit card assemblies or modules by means of unique interface backplanes configured to engage the common backplane connectors and the connectors on the circuit card assemblies. The system is specifically described in conjunction with electrical and optical bus interfaces.

Abstract: A transmission medium consists of a dielectric waveguide shielded by a metal guide. The guide is particularly suitable for providing low insertion loss, convenient transfer of power from one such transmission line to another and for the trouble free handling of high power levels at many hundreds of watts. This type of transmission medium may be used to provide low loss combination of power signals that is low loss, compact while containing the solid state power amplifying elements (MMICs) and capable of high power.

Abstract: A compound and method for dielectrically heating plastic in a mold with an RF source. A novel molding compound includes, in one embodiment, plastic such as polystyrene having a first dielectric constant and a water based resin such as phenolic resin. A lossy additive, such as a chemically inert low dielectric material, having a second dielectric constant substantially lower than that of the plastic, is added to the molding compound. The lossy additive increases the RF energy absorbed by the plastic molding compound thereby reducing heating time in the mold.

Abstract: An apparatus and method are disclosed of providing position indicating signals to a GNSS receiver in an area of poor reception of satellite signals from the GNSS or when a dedicated system under local control is required. The method includes the steps of disposing a plurality of stationary transceivers proximate the area of poor reception and calculating a global position of each stationary transceiver based upon information contained within signals received from at least some satellites of the GNSS. The method further includes the steps of transmitting a local global positioning signal from each of the stationary transceivers to the GNSS receiver in the area of poor reception, such local global positioning signals including at least the global position of the transmitting stationary transceiver.

Abstract: Disclosed are systems, pseudolite transmitters, receivers, and methods of using the same to navigate. An airborne pseudolite transmitter transmits a first spread spectrum signal indicative of a first fixed location spaced apart from a current actual position of the transmitter. The airborne pseudolite transmitter also transmits a corrections signal indicative of a vector error correction between the first fixed location and the current actual position of the transmitter. A receiver receiving the first spread spectrum signal and the corrections signal calculates its location in response thereto.

Abstract: A wideband phase and frequency modulator using a direct digital synthesis alias frequency band is described. The modulator is spurious free by the utilization of a fixed frequency at the output of the direct digital synthesizer wherein only certain submultiples of the clock frequency are used. Known frequency ratios relative to the clock frequency of the direct digital synthesizer (DDS) cause the DDS to function as a simple divider resulting in extremely low spurious levels when additional conditions are met. An additional frequency synthesizer may be utilized to achieve a tuning range since the DDS output is preferably held at a fixed frequency. At least one additional mixing operation is utilized for upconversion to a microwave frequency. Since fixed frequency ratios are used, implementation simpler than a full DDS may also be constructed consisting of digital modulators, multiplexers, digital to analog convertors, and filters.

Abstract: A method of smoothing Kalman Filter position states forming a "groundtrack" in a receiver used in a satellite based positioning system (e.g. GPS). In such systems, data pairs including an incoming value and a "raw" reliability estimate (e.g. a standard deviation) are normally fed directly to the Kalman Filter. The Kalman Filter computes the resultant and an overall uncertainty estimate by applying a "weight" to each successive incoming value based on its reliability. The Kalman Filter also estimates incoming values based on past values.The method involves the unique steps of replacing the raw reliability with a "modified" reliability if the incoming value is too far from the estimate in view of an adjustable limit envelope defined by the current uncertainty estimate and reliability value. If the difference between what we get and what we expect is small, then the reliability value is passed without modification.

Abstract: Provided are a method of and a circuit for processing GPS signals in the L1 frequency band centered around frequency f.sub.L1 and GPS signals in the L2 frequency band centered around frequency f.sub.L2. The L1 frequency band signals are combined with the L2 frequency band signals to obtain a combined signal having both an L1 frequency band component and an L2 frequency band component. The combined signal is frequency converted by mixing it with a local oscillator signal centered around a frequency f.sub.L0 to obtain a frequency converted combined signal centered around a third center frequency f.sub.C3. The frequency converted combined signal is filtered to provide an output signal having substantially all of its components centered around the third center frequency f.sub.C3. The frequency f.sub.

Abstract: A backlight for liquid crystal displays which includes several closely spaced lamps and a sculptured optic element disposed behind the lamps wherein, the sculptured optic element has a reflective back side and a partially reflective front side and an optically transmissive medium disposed there between. The optic element being sculptured so as to direct light rays emanating from the back of the lamps and from the side of the lamps in a direction away from colliding with other lamps and in a direction toward the median surface. The optic element essentially gathers light from behind and between the lamps and directs it in a direction toward the viewing surface.

Abstract: A system for resynchronizing the timing and carrier phases of a modem receiver signal to enable the receiver to quickly reacquire the timing phase and the carrier phase, and thereby restart the demodulation process. The system provides accurate estimates of the timing and carrier phases, as well as a gain correction factor to provide for proper alignment for decoding. The discrete Fourier transform of the received signal is multiplied by the complex conjugate of the discrete Fourier transform of the transmitted signal to produce estimates of the desired phases. Gain control and carrier phase control are performed to determine corresponding error signals to adapt the resultant estimated timing and carrier phases, and gain correction.