Abstract: A terrain advisory system for an aircraft is disclosed. The terrain advisory system includes a processing unit, a display unit coupled to the processing unit where the display unit displays a map, and a database coupled to the processing unit. The system also includes a sensor system coupled to the processing unit and a terrain awareness and warning system (TAWS) coupled to the processing unit. The TAWS generates cautions and alerts. The processing unit includes a program that generates a terrain advisory envelope extending beyond the distance and lateral envelope within which the TAWS provides cautions and alerts. The terrain advisory envelope is distinguished from TAWS cautions and alerts with a graphical appearance that differs from the graphical appearance of TAWS cautions and alerts.

Abstract: A power amplifier for a dual antenna is disclosed. The power amplifier comprises at least four controlled amplifier loops receiving a signal to be transmitted. The power amplifier also comprises a first combining structure combining at least two of the amplifier loops and a second combining structure combining at least two of the amplifier loops. The power amplifier also comprises a ninety degree hybrid receiving output from the first and second combining structures and providing output to a first antenna output and a second antenna output.

Abstract: A method of detecting GPS signal tampering uses two GPS receivers. A first receiver measures carrier phases of two or more satellite signals and of a tampered signal. A second receiver measures carrier phases of the two or more satellite signals and the tampered signal. A baseline vector between the receiver antennas is measured. Direction cosine vectors of the two or more satellite signals are computed and a dot product is computed from the baseline vector to translate measurements made at antennas of the GPS receivers to a virtual zero baseline condition. The carrier phase measurements are double differenced to obtain double difference residuals. A test statistic of the double difference residuals is computed and tested for phase coherency. An inconsistency in measured signals is flagged when there is an inconsistency in phase coherence indicating the tampered signal is present.

Abstract: A method of determining transmission parameters for a wireless transceiver is disclosed. According to the method, a state table is loaded into a transceiver. The state table includes a plurality of states, each of which has a set of transmission parameters associated therewith. Based upon characteristics of the signals received from a signal source, the transceiver is assigned a first state. The received signals are received and processed using the set of transmission parameters associated with the first state. It is determined whether an observed behavior of the received signals exceeds a threshold associated with the first one of the plurality of states. The transceiver is assigned a second state when the behavior exceeds the threshold. The received signals are received and processed using the set of transmission parameters associated with the second state.

Abstract: A method and system for providing time division multiple access communications is disclosed. The disclosure includes sending a first message in a time slot. The time slot has a slot length. The first message has a first time associated therewith. The first time includes the time required to send the first message and the propagation delay associated with the reception of the first message by a second transceiver. The disclosure also includes determining time remaining in the time slot for sending a second message. The time remaining is based on the first time and the slot length. The disclosure also relates to sending a second message in the time slot if the length of the second message plus the length of the propagation delay associated with the second message is less than the time remaining in the time slot.

Abstract: A one-dimensional electromagnetic band gap (EBG) waveguide phase shifter electronically scanned array (ESA) horn antenna utilizes a linear array of EBG waveguide phase shifters for scanning and radiating a beam. A linear array feed feeds the linear array of EBG waveguide phase shifters. A horn directs radiation from the linear array of EBG waveguide phase shifters. Each of the EBG waveguide phase shifters is a waveguide with vertical and horizontal sidewalls. EBG devices are located on the vertical waveguide walls to shift phase to scan the beam.

Abstract: A weather radar system or method can be utilized to adjust a position of a weather radar system. The weather radar system can utilize processing electronics coupled to an antenna control system. The processing electronics can determine an error associated with the position of the weather radar antenna and adjust the position of the weather radar antenna in response to data related to returns received by the weather radar antenna and data related to expected returns.

Abstract: A method, apparatus, and computer for enhancing the quality of images that have been subjected to degradation. One example of such degradation occurs as the result of haze in the atmosphere. An enhancement function is derived according to a reference digital image and a degraded version of the reference digital image. The enhancement function is applied to a new digital image to produce an enhanced digital image.

Abstract: A method of minimizing detectability of an electronically communicated message is disclosed. A predetermined frequency modulation pattern about a nominal transmission frequency is defined. The predetermined frequency modulation pattern is suitable to vary the nominal transmission frequency during a dwell period. The dwell period is divided into a plurality of sub-dwell periods. Each sub-dwell period has a nominal sub-frequency assigned thereto according to the predetermined frequency modulation pattern. The plurality of sub-dwell periods and the respective assigned nominal sub-frequencies are randomly or pseudo-randomly ordered. The message is transmitted according to the random or pseudo-random ordering of the nominal sub-frequencies.

Abstract: A method of characterizing a maximum height of a storm cell for an aircraft is provided. First reflectivity data formed from a first scan of a storm cell by a radar is received and a first centroid of the storm cell is identified. Second reflectivity data formed from a second scan of the storm cell by the radar is received and a second centroid of the storm cell is identified. A scan axis for a third scan of the storm cell based on the first centroid and the second centroid is determined. Third reflectivity data formed from the third scan of the storm cell by the radar at a first time is received. The third reflectivity data is sampled to form pixel data that includes a reflectivity indicator determined for each pixel formed from the third reflectivity data. A maximum height of the storm cell is determined by processing the pixel data.

Abstract: A weather radar system or method can be utilized to determine non-hazardous weather region for an aircraft. The weather radar system can utilize processing electronics coupled to an antenna. The processing electronics can determine presence of the non-hazardous weather region in response to data related to returns received by the weather radar antenna. The data can include a spatial frequency parameter or reflectivity gradient.

Abstract: The disclosure is directed to a system for detecting digitally modulated waveforms on a transmission channel. The system includes an amplitude modulation detector configured to detect amplitude variations on the transmission channel. The system also includes a first bandpass filter configured to receive a signal from the amplitude modulation detector monitoring the transmission channel and tuned to a wavelength corresponding to the symbol rate of the digitally modulated waveform to be detected. Further, the system includes a second bandpass filter configured to receive the signal from the amplitude modulation detector monitoring the transmission channel and tuned to a second wavelength. Further still, the system includes a means for comparing the output of the first and second bandpass filters to determine the presence of a digitally modulated waveform.

Abstract: A weather radar system or method can be utilized to determine potential weather hazard for an aircraft in a terminal area. The weather radar system can utilize processing electronics coupled to an antenna. The processing electronics can determine presence of the potential in response to data related to returns received by the weather radar antenna. The data can include a mean velocity parameter or a spectral width parameter or reflectivity.

Abstract: A diversity code transmission system is disclosed. The diversity code transmission system comprises an encoder encoding a set of bits. The system also comprises an interleaver receiving the encoded bits and providing an output. A coder or modulator for providing a first transmission signal is also used. The interleaver iteratively receives its own output to provide an iterated output to a coder or modulator to provide a diversity transmission signal. The receiving system supports iterative decoding and joint iterative demodulation and decoding.

Abstract: An orthogonal frequency division multiplexing (OFDM) communications system transmits data on a plurality of subcarriers and has a featureless synchronization signal. The OFDM communications system transmits synchronization tones on pseudorandomly selected subcarriers. A receiver generates the same synchronization tones and performs a correlation on the received signal with the receiver synchronization tones. The correlation is performed at the beginning and the end of the synchronization symbol. A product of the two correlations results in a magnitude peak and a phase difference. The magnitude peak is used to determine the location in time of the sync symbol and the phase difference is used to determine the frequency offset of the received signal.

Abstract: Low-latency satellite Internet service from a commercial off-the-shelf two-way satellite Internet system for aircraft under marginal communications link conditions is provided. One or more identical Internet requests each having a unique ID are sent in rapid succession from the aircraft. The one or more identical Internet requests are received at a satellite and sent to a network operations center (NOC) where they are forwarded over the Internet to an appropriate Web site. Identical Web pages are retrieved for the identical Internet requests by the NOC and transmitted to the satellite and then relayed to the aircraft. The requested Web page data is fused for the requested Web pages into a single Web page response in accordance with the unique IDs in the server for viewing by a client PC with low-latency when a failure in transmitting and receiving identical Internet requests and requested Web pages occurs.

Abstract: An aircraft formation positioning system lead aircraft transmits a continuous RF signal and a periodic data burst with lead aircraft position. A follower aircraft receives the continuous RF signal and the periodic data burst. A follower aircraft resolver determines bearing, distance and elevation relative to the lead aircraft from the continuous RF signal. The follower aircraft transmits an intermittent RF signal and a periodic data burst with its relative position determined from the continuous RF signal. The lead aircraft receives the intermittent RF signal and the periodic data burst from the follower aircraft. A lead aircraft resolver performs an independent measurement of the lead aircraft position relative to the follower aircraft from the intermittent RF signal. A lead aircraft Kalman filter connected to the lead aircraft resolver and receiver correlates the independent measurement of the lead aircraft position relative to the follower aircraft with the received periodic data burst.

Abstract: A system and method for providing quality of service (QoS) service over a mobile IP network with dynamic domains, multiple or distributed QoS managers per domain and/or with network congestion feedback being used to establish an estimated total domain bandwidth which is used for regulating access to a domain.

Abstract: An apparatus and method provides efficient parallel processing for use with a single-bit sampler that provides single-bit samples at a high sample rate. A serial-to-parallel converter converts the single-bit samples into parallel single-bit samples at a reduced sample rate. A digital quadrature mix performs a frequency shift to the parallel single-bit samples and simultaneously performs a real-to-complex conversion of the parallel single-bit samples from the serial-to-parallel converter to provide parallel I and Q output values at an intermediate frequency. The serial-to-parallel converter has shift register stages that provide a memory for use in functional realization of a boxcar filter and decimation-by-two in the digital quadrature mix. The digital quadrature mix utilizes logic to route and invert the parallel single-bit samples resulting in the parallel I and Q single-bit output values. Additional filter and decimate stages may be used to process the parallel I and Q single-bit output values.

Abstract: The present invention is directed to a system and method for a safe flight display through increasing situation awareness by an optimal presentation, given limited capacity of the system. The system may determine which terrain area needs a detail representation and which area needs a coarse representation. A view-dependent visual error metric may be utilized to define and maintain an error bound and accurately minimize the amount of terrain data being depicted. By performing a breadth-first search on the terrain database, a user can determine amount of geometry to be displayed with limited bandwidth of data presentation. The user may be allowed to scale the application to his/her desired level of detail, given a capacity of the system. Therefore, the system may provide a safe flight display with an anticipated and graceful (all portions of the screen would be given an equal quality representation) degradation in performance upon the choice of the user.