Abstract: An improved computer architecture and system advantageously combine the beneficial characteristics of a high level object oriented programming language with an optimized processor for efficient application to real time embedded computing problems. Additionally, an improved method for resolving symbolic references in code generated by compiling source code written in an object oriented programming language to the corresponding logical memory addresses stores look-up information with the object itself after the first encounter of a given symbolic reference, whereby the logical memory address information is available for subsequent encounters of the symbolic reference, and whereby no modification of the program instructions containing the symbolic reference is necessary. In a preferred embodiment, the Java™ programming language is used.

Abstract: An RF translator is placed on an artillery shell. The RF translator receives a GPS signal, converts the GPS signal to an S band signal, and then transmits the S band signal. The S band signal is received by a ground antenna and it is converted back to an L1 GPS signal. The transmission of the S band signal to a ground antenna induces two effects which make fast direct P(Y) acquisitions difficult. First, since the artillery shell is moving, a carrier Doppler is induced on the S band signal. Second, the time delay caused by the transmission of the S band signal affects the nominal code phase for acquisition. Acquisition of GPS signals corrupted by second frequency data effects require special compensation if fast direct P(Y) code acquisition is desired. A carrier Doppler and a code phase compensation term allow the GPS ground receiver software to focus its search window for the carrier frequency (code rate) and the code phase (time delay).

Abstract: A bi-directional energy storage module and method of operation is disclosed. The converter includes an inductive component, an energy storage element, two diodes and two switches. One switch is positioned in a first sub-circuit between an input voltage source and the inductive component and the other switch is positioned in a second sub-circuit between the inductive component and the energy storage element. The inductive component can be an inductor or a transformer. The energy storage element can be a battery or a capacitor. A hysteretic control structure can be used to activate and control the charging and discharging modes of operation. Voltage across the energy storage element and current through the inductive component are monitored. The switches are controlled to keep the monitored parameters within established bounds. Inrush current problems are eliminated and simple gate drive mechanisms are facilitated. The invention can be used in battery charging and discharging applications.

Abstract: An assembly for providing microradian adjustment of the alignment of objects such as optical devices is disclosed. The microradian adjustment assembly is comprised of a mounting plate suitable for mounting an object and a torque adjustment assembly. A circular channel is formed in the plate so as to define a disk area surrounded by a deflection area. The torque adjustment assembly torsionally deforms the deflection area, rotating the disk area with respect to the mounting plate. This rotation is utilized to provide microradian adjustment of the alignment of the object.

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 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: 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 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: 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: 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 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 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: 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 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.

Abstract: A dielectric heater for subject material by connecting an RF source, modulated to produce a spread-spectrum signal to a radio frequency applicator for the subject material, without requiring an impedance matching network. The carrier frequency of the RF source may be selected to match the impedance of the subject material and applicator network.