Abstract: Disclosed are a global navigation satellite system (GNSS) landing system (GLS) and methods of using the same to calculate a vertical deviation from the glide slope of the aircraft. A GNSS antenna and position determining circuitry are used to determine the position of the aircraft as a function of received GNSS positioning signals. Vertical deviation computation circuitry coupled to the position determining circuitry calculates an angular vertical deviation &agr;v from the glide slope of the aircraft as a function of the total horizontal distance between the aircraft and a GLS elevation reference point (GERP).

Abstract: An optical combiner with a Fresnel lens having a Fresnel surface coated with a thin film spectrally selective reflective coating configured to reflect light within a first wavelength range, and transmit light within a second wavelength range is provided. The optical combiner also includes a covering which covers the Fresnel surface and the reflective coating to provide a generally planar surface which is substantially parallel to a similarly planar exterior surface of the Fresnel lens. The covering may take the form of an optical adhesive (or of a second Fresnel lens) with an index of refraction which substantially matches the index of refraction of the Fresnel lens.

Abstract: A sigma-delta low-pass/band-pass based modulator for analog-to-digital converters includes at least one or more tunable band-pass filter stages. The filter stages are configured arrays with one or more parallel filter stages arranged as a group, and with one or more groups in cascade. The input signal is provided to all filter stages in the first group, and the outputs of the last group are combined and provided to the output processing elements. The output processing elements provide the signal conversion to the converter output, as well as the inverse conversion of the output signal to form the feedback signal or signals. All filter stages receive a feedback signal from the output processing elements. Each of the tunable band-pass filter stages is independently tunable to a respective predetermined frequency. At least one of the filter stages can be configured to support low-pass operation in conjunction with band-pass operation for increased low-pass signal bandwidth.

Abstract: A transistor commuted double balanced mixer that uses a Gilbert cell mixer quad transistor core. The RF input differential pair is deleted from the standard Gilbert cell mixer configuration. A transformer is used to apply the RF input through resistors to the Gilbert cell mixer quad transistor core.

Abstract: A tunable bandpass sigma-delta modulator analog-to-digital converter (A/D converter or ADC) utilized in conjunction with a digital signal processor (DSP) to eliminate the analog frequency synthesizer in a radio design is disclosed. The sigma-delta ADC greatly reduces the analog circuitry requirements and ensures that the circuitry is suitable for very large scale integration (VLSI). The all-digital DSP ensures the highest level of VLSI and provides for high performance frequency synthesis and translation completely in the digital domain.

Abstract: A system and method for capturing and processing audio and video images for optimized transmission over a lower bandwidth communications channel are disclosed. A digital processing system receives video and audio signals from a media source such that the video and audio signals are representative of captured images and sounds as a multimedia signal. An optical processing system is coupled to the digital processing system and performs signal processing algorithms on the multimedia signal. A transceiver transmits the multimedia signal over a lower bandwidth communications channel wherein the multimedia signal is optimized for transmission over the lower bandwidth communications channel by the signal processing algorithms performed by the optical processing system.

Abstract: A magnetic sensor that measures the angle of the sensor's sensitive axis relative to a local magnetic field compensates the navigation solution of a MEMS-IMU/GPS navigation system. A stable navigation solution is thereby maintained. The magnetic sensor is mounted on a body axis of the vehicle perpendicular the spin axis of the vehicle. As the vehicle spins, the magnetic sensor provides an analog output voltage that varies sinusoidally with vehicle roll with the zero crossings occurring when the sensor's sensitive axis is perpendicular to the local magnetic field. The magnetic sensor measurements combined with knowledge of the local magnetic field relative to the local level reference are used to correct the navigation solution's roll error. Following high rate sampling of accelerometers and gyros, and algorithm to computational de-spin in the navigation solution is executed whereby navigation processing may be implemented with a non-rolled vehicle body frame algorithm.

Abstract: An improved traffic alert and collision avoidance method and device wherein TCAS data is augmented by higher resolution radar data. By using radar to search out targets, altitude information can be developed for those aircraft not equipped with altitude reporting transponders. The improved accuracy also allows angle/angle perspective display of air traffic and thus provides enhanced situational awareness.

Abstract: A differential GPS receiver system in which a first receiver at a known location generates pseudo range correction data and a second GPS receiver at a nearby second known location uses the data to determine an enhanced calculated position of the second GPS receiver, which is then compared with the known second location. If the enhanced calculated position falls within an acceptable level of error from the known position, then the pseudo range correction data is transmitted to mobile receivers.

Abstract: A global positioning system (GPS) receiver or navigation apparatus for use on an aircraft is disclosed. The receiver implements improved methods of performing both navigation and fault detection and exclusion (FDE) functions. The GPS receiver includes an antenna adapted to receive GPS satellite signals from each of a multiple GPS satellites. Navigation solution determining circuitry coupled to the antenna receives the GPS satellite signals and performs navigation and FDE functions. The navigation solution determining circuitry is adapted to determine both a horizontal position of a least squares navigation solution for the receiver and a horizontal position of a first navigation solution for the receiver as functions of the received GPS satellite signals. The horizontal position of the first navigation solution for the receiver is offset from the horizontal position of the least squares navigation solution for the receiver.

Abstract: Disclosed are avionics systems and methods of using the same to monitor a pitot-static system for blockages. A first aircraft movement rate is calculated as a function of a pressure sensed using the pitot-static system. A reference movement rate is calculated using an independent navigation system such as an inertial reference system, a global positioning system, or an attitude heading reference system. The calculated first aircraft movement rate is compared to the calculated reference movement rate to determine whether the calculated first aircraft movement rate falls within a predetermined tolerance range about the calculated reference movement rate. If the calculated first aircraft movement rate falls outside of the predetermined tolerance range about the calculated reference aircraft movement rate, it is determined that a blockage exists in at least one of a pitot tube or a static port of the pitot-static system.

Abstract: A method and apparatus for determining the inclusion or exclusion of a current position of an aircraft within a satellite communication spot beam, which uses a technique of slightly moving the position being checked for inclusion, when it is determined that a ray drawn from the current position is coextensive with an endpoint of any line segment making up a boundary of the spot beam.

Abstract: An automatic storm finding weather radar is disclosed that uses a storm finding algorithm to automatically control the weather radar to eliminate manual control. The storm finding algorithm uses the 0° C. isotherm altitude where precipitation is most likely to first occur to calculate an altitude search layer to find storms. The storm finding algorithm calculates the antenna upper and lower tilt angles and the number of scans to search the altitude search layer. A list of useable antenna tilt values is formed to drive the antenna controller. The antenna controller scans the antenna at the lower tilt angle and then moves to the next tilt angle until the search is complete. The search is then repeated using any new data.

Abstract: A method of generating a differentially corrected pseudorange residual in a differential global positioning system includes tracking at a base station first and second GPS signals, having first and second frequencies, from a first satellite. At the base station, a first pseudorange measurement is determined from the tracked first GPS signal. At the base station, a first smoothed pseudorange measurement is calculated from the determined first pseudorange measurement as a function of both the first and second GPS signals. The first smoothed pseudorange measurement is provided to a remote GPS receiver. The remote GPS receiver calculates the differentially corrected pseudorange residual as a function of the first smoothed pseudorange measurement provided by the base station.

Abstract: A positioner (or gimbal assembly) for a compact antenna assembly is disclosed. The positioner provides accurate pointing of the antenna assembly (typically a narrow beam radio frequency (RF) radiating assembly) mounted on a rapidly moving platform. The positioner is comprised of a first, second, and third axis assemblies which support the antenna assembly and allow rotation of the antenna assembly about first, second, and third axis. The axis assemblies are arranged so the first, second and third axis are non-orthogonal and intersect at the approximate geometric center of the antenna assembly allowing continuous and independent rotation of the antenna assembly about each axis within a confined volume.

Abstract: A radio frequency combining system is disclosed that uses commercially available quadrature hybrid couplers configured in a unique manner to combine any radio frequency sources such as transmitters into a single load such as an antenna. The radio frequency combining system is bidirectional and can be used in the receive mode to combine the output of a receive antenna with outputs from an interference canceller to then supply received signals to a multiple receiver system.

Abstract: An LCD heater and method having temperature sensors made by electrically isolating portions of ITO across a display surface and measuring the resistance of such portions and developing an assessment of temperatures in the interior of the display surface based on sensor calibration data taken under known temperature conditions.

Abstract: A global positioning system (GPS) and auxiliary receiver receive limited range position signals broadcasted from telemetry transmitters when in an urban canyon environment. The limited range receivers preferably are implemented as part of the lighting infrastructure of the environment. The limited range receivers derive power from light from the lighting infrastructure. The receivers can also include a transmitter for retransmitting the receive position data and an ID code to a central processing center.

Abstract: A method for designing an aircraft to ground communications system identifies a plurality of unique functions in the communications system. The components, hardware and software, necessary to implement each of the plurality of unique functions are isolated such that the components for implementing a specific function are partitioned to allow independent testing and certification of the hardware and software components for each unique function.

Abstract: A system for voice announcing air traffic controller to pilot data link communication messages of a type which are in conformance with predetermined industry standard message formats, the system and method including a voice annunciation to the flight crew of such messages with the aid of a database of predetermined speech files which correspond to predetermined controller pilot data link communication messages. The flight crew is able to select a language, gender, dialect, accent, etc. of the announced voice message so as to provide for enhanced communication of air traffic control messages to the flight crew.