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 liquid crystal display optical component stack-up is created with reduced defects typically caused by adhesive materials used to attach optical components to the liquid crystal display. A layer of silicone gel is positioned between a surface of the liquid crystal display and a surface of a first optical component. The layer of silicone gel attaches the first optical component to the liquid crystal display such that strain on the liquid crystal display is minimized.

Abstract: A method for real-time data exchange between an RF modem of a mobile data terminal and a base station host computer of a mobile radio-frequency data communications network is disclosed. In a preferred embodiment, the data exchange timing architecture of the present invention reduces message error rates by accurately predicting signal presence by using a modem hosted by the central processing unit of a mobile data terminal. RF network signal synchronization is improved through precise prediction of the likelihood of message presence, a method that significantly reduces message errors triggered by inadvertent synchronization on signal noise.

Abstract: An altimeter is disclosed which includes an arcuate top portion and an arcuate bottom portion. Side portions connect the arcuate top portion to the arcuate bottom portion. The side portions have a curvature less than a curvature of the top portion or the bottom portion, thus giving the altimeter a narrower footprint while preserving important features of conventional dial-type altimeters. An indicator moves about the perimeter of the altimeter based on altitude information, thus displaying altitude of the aircraft.

Abstract: An inertial reference system for determining the attitude and rate of change of attitude of a vehicle such as an aircraft is disclosed. Redundancy of the inertial reference system may be accomplished by replacement of one of the fiber optic gyroscopes of an otherwise dual fiber optic gyros installation with a low-cost reference IMU. Failure detection and isolation of a fiber optic gyroscope system may be accomplished with a low-cost reference IMU rather than with an additional fiber optic gyroscope. The information provided by the eliminated fiber optic gyroscope is synthesized from the output of the remaining fiber optic gyroscope and the output of the low-cost reference IMU.

Abstract: A fluorescent lamp drive circuit is disclosed. The fluorescent lamp drive circuit includes first filament drive circuitry coupled to the filaments of the lamp for driving the fluorescent lamp with a first waveform having sufficient amplitude such that gases in the fluorescent lamp are not allowed to extinguish during a prolonged period of operation. The fluorescent lamp drive circuit also includes second filament drive circuitry coupled to the filaments of the lamp for adjustably driving the fluorescent lamp with a second waveform during the prolonged period of operation. The second waveform has an amplitude which is adjustable over a wide range of voltages to achieve a wide range of fluorescent lamp luminance levels. Synchronization circuitry provides an input to the second filament drive circuitry to automatically facilitate the efficient transfer of power from the second filament drive circuitry to the fluorescent lamp over a wide range of lamp pressures and operating temperatures.

Abstract: The invention is a way to detect and correct data inversions or other phase ambiguities in a modem's data, without incurring a significant penalty in error rate performance, throughput, or overhead, by making a particular use of the error detection and correction (EDAC) code which would typically be used for random errors. The decoder is set up so that the inverted data or out-of-phase data generates a distinctive syndrome which signals to a phase corrector.

Abstract: A system for adaptively determining a bitwise weighting factor for coded binary data comprising a correction unit that provides an overall weighting factor representative of the sum of the products of the individual symbol probability factor times the bit value.

Abstract: An improved fluorescent lamp and a method of preparing the same are described. The fluorescent lamp includes a tube having a first surface which serves as a substrate. A continuous layer of aluminosilicate sol-gel material having phosphor particles embedded therein is formed on the first surface of the tube. The continuous layer of sol-gel material having phosphor particles embedded therein is formed by first preparing an aluminosilicate sol-gel solution. The phosphor particles are next mixed in the aluminosilicate sol-gel solution to obtain a phosphor particle carrying aluminosilicate sol-gel solution. Then, the first surface is coated with the phosphor particle carrying aluminosilicate sol-gel solution. The phosphor particle carrying aluminosilicate sol-gel solution is dried on the first surface to form a phosphor particle containing sol-gel layer.

Abstract: Conventional packaging of optical sensors is of little assistance in determining the location and attitude of the focal place of the sensor 10, since package tolerances lack the requisite precision. Each sensor 10 must be separately focused to its optical assembly 40. Such focusing is expensive, as is the package itself. This invention instead mounts the sensor 10 directly onto one face 28 of a transparent plate 18. Radiation is focused through the plate 18 and onto the sensor 10. Precision alignment targets 12, 22 are formed separately on the sensor 10 (providing a known location of the active image area 14 with respect to the target 12) and on the plate 18 (providing a known location of the edges 24 of the plate 18 with respect to the target 22). The targets 12, 22 are aligned, and contact pads 16, 30 on the sensor 10 and on the plate 18 are joined by electronically conductive bumps 36 of known thickness. The plate 18 itself is of known thickness.

Abstract: A display element in a liquid-crystal display having a tailored pushdown voltage is described wherein the pushdown voltage of the display element may be tailored to a predetermined compensation level by varying the size of the thin-film transistor switch of the display element, by varying the size of the storage capacitor of the display element, or by varying both the size of the thin-film transistor switch and the size of the storage capacitor. The pushdown voltage of the display element may be further tailored in conjunction with the cell gap of the display panel. Precise manipulation of the output of the liquid-crystal display may be achieved through manipulation of the size of the thin-film transistor and the storage capacitor wherein various parameters may be controlled including luminance, color balance and aperture ratio for individual colors.

Abstract: A fluorescent lamp is provided which is resistant to lumen depreciation. The fluorescent lamp includes a tube constructed of an ultraviolet (UV) radiation transmissive material. A gas inside of the tube produces UV radiation in response to a stimulus. Phosphor particles in a phosphor particle containing coating adhered to an outer surface of the tube absorb UV radiation produced by the gas inside of the tube and producing visible light in response.

Abstract: A method and apparatus for driving a fluorescent lamp is described wherein the fluorescent lamp is operated in the phanotronic, or hot-cathode, mode. The filament preheat current is decoupled from the arc current through synchronization of the filament voltage and arc voltage waveforms to provide sense windows during which the filament condition may be precisely and accurately determined. Sensing circuits provide correctional feedback to the filament voltage signal to provide optimal filament heating.

Abstract: A automatic skywave communications system includes a control channel and one or more traffic channels for voice or data communications. The system automatically establishes and maintains traffic radio links. The system measures, reacts, signals and adapts system parameters.

Abstract: A system for processing signals by utilizing a tracking loop that contains two or more detectors that operate simultaneously in order to detect a frequency shift in the locally generated reference signal. A correction can then be transmitted to the tracking loop filter to minimize the effect of the detected frequency shift. In this manner lock can be maintained without the expenditures associated with the use of temperature controlled or compensated oscillators.

Abstract: A method of processing wireless signal of data pulses or packets in a communication system, in which a portion of the data pulses in an individual signal are utilized to determine a rate of time shift for eliminating or minimizing the effects of Doppler shift in the intra-data pulse processing. One embodiment of the invention provides a method of utilizing the time refinement section of a JTIDS waveform for the purpose of determining an intra-burst data correction factor based upon the average shift of the midpoint of the sampled time refinement section pulses.

Abstract: A method of and apparatus for charging select pixel elements of an active matrix liquid crystal display to gray scale voltage levels is disclosed. Which of the pixel elements of the display are to be charged to a first gray scale voltage level is determined. During a scan of the row conductors for the first gray scale voltage level, pixel elements in each enabled row which are to be charged to the first gray scale voltage level are selected. After completion of the scan for the first gray scale voltage level, all of the selected pixel elements in the display are simultaneously charged to the first gray scale voltage level.

Abstract: A device and a method of manufacture for the device, in which the device is a metallic canister having a detachable lid that is fastened onto the canister having an indium-tin intermetallic gasket disposed between the lid and the edge of the canister adjacent to the lid. Heating the entire apparatus at a predetermined temperature less than the melting point of indium-tin intermetallic for a specified time period such that the indium and a tin coating on the lid and canister surface interact to form an intermetallic compound that provides a seal which will satisfy operating requirements for being, designated a hermetic seal. The condition of the seal improves over time, due to the continued interaction between the tin and indium alloy.

Abstract: A passive matrix liquid crystal display and a method of driving the same are provided. A desired RMS voltage to be achieved during a first frame is determined for each pixel element of the display. A modulation coefficient is determined for each pixel element as a function of the desired RMS voltage for the pixel element during the first frame. For each cycle of the frame, a phase delay is determined for each column drive waveform as a function of the sum, over all rows, of the product of each modulation coefficient of a pixel element in the column and the phase delay of the corresponding row drive waveform during the cycle.