Abstract: An integrated navigation system includes a prime mission navigation system (e.g., a military code GPS-based flight management system), a second navigation system (e.g., a civil code GPS-based navigation system) and an integrity check system. The first navigation system receives first positioning signals and generates a first navigation solution based on the first positioning signals. The second navigation system receives second positioning signals and generates a second navigation solution based on the second positioning signals. The integrity check system receives the first navigation solution and the second navigation solution, compares the first navigation solution to the second navigation solution, and generates a validity signal based on the comparison.

Abstract: A temperature stabilized CMOS oscillator circuit modifies the gain of a CMOS oscillator transistor to cancel the gain variation over temperature using a bias circuit. The bias circuit utilizes a combination of two current mirrors to establish a temperature compensating supply current to a CMOS oscillator transistor. A primary current mirror and a temperature variable resistor establish a current in the current mirror output to the CMOS oscillator transistor. A secondary current mirror and a temperature variable resistor divert current from the primary current mirror over temperature to vary the current mirror output to the CMOS oscillator transistor to compensate for its gain variation.

Abstract: A system and method for safe and secure stowage of an on-board entertainment display utilizing at least one dual biased latch in the stowage compartment and a complementary recess in the display assembly such that the latch prohibits un-commanded display deployment, even in the absence of electrical power to the unit.

Abstract: Multiple Java Virtual Machines (JVMs) operate on a single direct execution JAVA processor with each JVM operating in a separate time slice called a partition. Each JVM has its own data and control structures and is assigned a fixed area of memory. Each partition is also allotted a fixed period of time in which to operate, and, at the end of the allotted time, a context switch is forced to another JVM operating in the next partition. The context switch does not transfer control directly from one JVM to another JVM. Instead, at the end of a partition time period control is switched from the currently operating JVM to a “master JVM” during a time period called an “interstice.” The master JVM handles system interrupts and housekeeping duties. At the end of the interstice time period, the master JVM starts a proxy thread associated with the next JVM to become operational. The proxy thread handles JVM-specific interrupts and checks the status of the associated JVM.

Abstract: A high pass delta-sigma modulator apparatus is disclosed for use in analog-to-digital and digital-to-analog converters. The apparatus includes a signal input, a differentiator component, a signal transducer producing an output signal, an inverse signal transducer producing an input compatible feedback signal, and a feedback loop coupling a feedback signal back to said differentiator component. Also disclosed is a Nyquist response restoring delta-sigma modulator based analog-to-digital and digital-to-analog converter apparatus having a first modulator set, a first scaling component, a second modulator set and a post processing combiner. In the various embodiments, the modulator sets can include an analog signal input, a digital signal input, a quantizer, a digital resolution rounder, a digital resolution truncator, a digital-to-analog signal transducer, a digital resolution expander, a delta sigma modulator structure, a feedback structure, an analog signal output, and one or more digital signal outputs.

Abstract: A column driver circuit for a liquid crystal display (LCD) system provides a large number of gray-scale values without significant cost, power requirements, and size requirements. The column driver circuit avoids the use of conventional multiplexer based systems and utilizes a digital-to-analog converter to provide voltage levels through analog memory devices. The analog memory devices are sample-and-hold circuits, each having two capacitors and three switches.

Abstract: A retractor device for the LCD unit of an on-board entertainment unit is disclosed. The retractor device uses capacitors as storage device to provide electrical energy to drive the retractor motor in the reverse direction in the event of power outage. Under normal operating conditions, the deployment and retraction of the LCD is performed by the motor, with its polarity switched by a relay. At the same time, a storage capacitor is charged up. In the event of power outage while the LCD is in a deployed mode, the energy stored by the capacitor is discharged to drive the motor's retraction mechanism. Blocking diodes may be used on the discharge path to ensure that the discharge path goes toward the motor.

Abstract: A receiver and method for acquiring a large pseudorandom (PN) sequence such as a GPS P(Y) code signal with poor or no knowledge of an external time reference are disclosed. A reference PN sequence is sectioned into a predetermined number of subsequences. The large PN sequence to be acquired is received from a remote source. The received PN sequence is correlated with each of the predetermined number of subsequences simultaneously. The large PN sequence is acquired, and a GPS solution may be provided, in the event the correlation produces a correlation between the received PN sequence and one of the predetermined number of subsequences. The large PN sequence may acquired without knowledge of an external time reference in a reasonable amount of time (e.g., less than ten minutes).

Abstract: A light reflector for use with a light source and a light detection mechanism is disclosed. The light source and the light detection mechanism are mounted on a substrate. The light reflector includes a generally hollow portion having a first end and a second end. A reflective surface is disposed upon the first end of the generally hollow portion. The second end is attached to the substrate such that the substrate and the light reflector define a substantially airtight enclosure that is of sufficient size to accommodate therein the light source and the light detection mechanism.

Abstract: A method of changing a preselect altitude value includes receiving an input from a pilot. In response, the preselect altitude value is changed by a first amount from a current preselect altitude value toward a minimum altitude value. The first amount that the preselect altitude value is changed by is dependent upon a proximity of the current preselect altitude value to the minimum altitude value such that if a difference between the current preselect altitude value and the minimum altitude value is greater than a first predetermined interval, the first amount is equal to the first predetermined interval. If the difference between the current preselect altitude value and the minimum altitude value is less than the first predetermined interval, then the first amount is less than the first interval, for example resulting in the preselect altitude value being set directly to the minimum altitude value.

Abstract: An apparatus and method for aligning portions of a tiled projection display which become misaligned during operation of the display, including interposing at least one two-dimensionally electro-mechanically gimballed glass plate in the projection path of one of the display sections. Sensing the misalignment of the tiles and automatically adjusting the alignment in response thereto. Further having apparatus and steps for alignment of the tiles based upon operational characteristics of an aircraft upon which the display is used.

Abstract: A multilevel power amplifier using hybrid couplers is disclosed. A splitter network is connected to an input amplifier stage that amplifies and modulates the input signal with the outputs of the splitter network connected to switches for selecting desired splitter output signals. The desired splitter output signals are amplified by power amplifier stages connected to the switches. A bypass network is connected to the splitter network and an output combiner network to bypass the power amplifier stages. The output combiner network is connected to the power amplifier stages and to the bypass network to combine the bypass signals and the amplified signals into a desired power output signal. Two or four power amplifier stages may be used to deliver power at low, medium, and high power levels.

Abstract: The present invention is directed to a method of determining an orientation of an object wherein a directional antenna of a global positioning system receiver acquires a position of a global positioning system transmitter. An orientation of the directional antenna of the global positioning system receiver is determined with respect to the global positioning system transmitter, the determined orientation of the direction antenna corresponding to the object so as to enable the orientation of the object to be determined.

Abstract: A method and apparatus for minimizing diffraction effects on flat panel displays. The flat panel display includes a plurality of display elements, each display element including a first structural feature having an edge and a second structural feature disposed on the first structural feature. The edge of the first structural feature causes incident rays from a point light source to generate diffraction effects due to the Fresnel reflectance difference in the boundary between the first and second structural features. The display further includes an edge texture on the edge of the first structural feature to minimize the diffraction effects into a more diffused diffraction pattern.

Abstract: A software record that identifies a software component associated with a processor in a distributed processing system is retrieved from a software configuration database. A check value is calculated for a copy of the software component loaded on the processor. The check value is compared to a second check value retrieved from the software record to verify the software component file.

Abstract: A power distribution system and method, including a direct-current current source which is commutated among a number of distribution circuits which function as independent and modular power sources. Each distribution circuit includes a capacitor which is connected to the direct-current current source through a switch. The load is connected in parallel with the capacitor. The capacitor is charged to a predetermined level, generally matching the required load voltage, and periodically checked and recharged as necessary. There may be a plurality of distribution circuits to provide power to separate circuits or specific portions of a larger circuit. By varying the switch timing and logic, the output voltage of each distribution circuit may be varied, allowing a centralized power supply to provide power to a variety of electrical components with varying voltage requirements.

Abstract: The column driver for a liquid crystal display (LCD) provides separate analog signals to each color element associated with the pixel. For example, a separate analog signal is provided to a red element, a blue element, and a green element. The driver circuit receives a digital signal representative of the gray scale voltage and provides the analog signal through a switch matrix to each color element. The driver circuit reduces undesirable color shifts as gray scale values are varied.

Abstract: An avionics test unit adapter for interfacing between an avionics test station and an avionics line replaceable unit, where the test unit adapter is blind mated with both. The test unit adapter has therein at least two rigid circuit cards used for signal distribution or transmission. The two rigid circuit cards being rigidly coupled to each other through an edge connector while each circuit card is mounted within the test unit adapter with the ability to float therein in at least three orthogonal directions.

Abstract: A method and apparatus for compressing video data images uses optical processing techniques. The method and apparatus perform holographic optical correlation and apply holographic optical correlation in a feedback loop. A codebook of images or primitives for the correlation are stored in a holographic library.

Abstract: A system is provided for mounting a head-up display in a cockpit of an aircraft, the cockpit including a front region and a back region, the head-up display including a computer adapted to process flight information, an optical unit adapted to project an image corresponding to the flight information processed by the computer, and a combiner adapted to display the image projected by the optical unit. The system comprises a frame with a front region and a back region, the frame including an optical unit interface for mounting the optical unit and a combiner interface for mounting the combiner, wherein the frame is adapted to be movably coupled to the cockpit such that the frame may be moved in a generally vertical direction between a plurality of positions relative to the cockpit.