Abstract: System, method and computer program product for determining bearing using ADS-B and TCAS standard reply bearing estimates are disclosed. In one embodiment, a method for determining bearing based upon ADS-B signals includes receiving ADS-B signals and standard transponder reply signals. A first bearing estimate is based on the ADS-B signal. A second bearing estimate is based on the standard transponder reply signals. A database is developed according to the first and second bearing estimates via the ADS-B and standard transponder reply signals. In one embodiment, where ADS-B signals are unavailable, associated ADS-B signals associated with the standard transponder reply previously stored in the database are used to determine bearing.

Abstract: System, method and computer program product for determining bearing using ADS-B and TCAS standard reply bearing estimates are disclosed. In one embodiment, a method for determining bearing based upon ADS-B signals includes receiving ADS-B signals and standard transponder reply signals. A first bearing estimate is based on the ADS-B signal. A second bearing estimate is based on the standard transponder reply signals. A database is developed according to the first and second bearing estimates via the ADS-B and standard transponder reply signals. In one embodiment, where ADS-B signals are unavailable, associated ADS-B signals associated with the standard transponder reply previously stored in the database are used to determine bearing.

Abstract: System, method and computer program product for determining bearing using ADS-B and TCAS standard reply bearing estimates are disclosed. In one embodiment, a method for determining bearing based upon ADS-B signals includes receiving ADS-B signals and standard transponder reply signals. A first bearing estimate is based on the ADS-B signal. A second bearing estimate is based on the standard transponder reply signals. A database is developed according to the first and second bearing estimates via the ADS-B and standard transponder reply signals. In one embodiment, where ADS-B signals are unavailable, associated ADS-B signals associated with the standard transponder reply previously stored in the database are used to determine bearing.

Abstract: A device for determining the bearing of a vehicle using Inertial Reference Unit (IRU) and Traffic Alert Collision Avoidance System (TCAS) data. The device includes a means to communicate with the vehicle such as a transmitter, receiver, and antenna. The device also includes a processor configured to receive the IRU and TCAS data from the vehicle via the communication means and then generate a bearing value using the received data.

Abstract: System, method and computer program product for determining bearing using ADS-B and TCAS standard reply bearing estimates are disclosed. In one embodiment, a method for determining bearing based upon ADS-B signals includes receiving ADS-B signals and standard transponder reply signals. A first bearing estimate is based on the ADS-B signal. A second bearing estimate is based on the standard transponder reply signals. A database is developed according to the first and second bearing estimates via the ADS-B and standard transponder reply signals. In one embodiment, where ADS-B signals are unavailable, associated ADS-B signals associated with the standard transponder reply previously stored in the database are used to determine bearing.

Abstract: A transmitter and method for transmitting transponder or TCAS signals uses linear amplification to save on circuit component weight, cost and size while enabling precise amplification and control of the transmitted signal.

Abstract: An apparatus and method determining angle-of-arrival of a received radio frequency signal, and apparatus and method for calibrating the angle-of-arrival determining apparatus.

Abstract: A transmitter and method for transmitting transponder or TCAS signals uses linear amplification to save on circuit component weight, cost and size while enabling precise amplification and control of the transmitted signal.

Abstract: A method and apparatus for transmitting a directional reply signals in response to Air Traffic Control Radar Beacon System and Mode Select signals interrogation signals. Two directional antennas independently acquire an interrogation signal and are connected by means of a configurable switch to a transponder. The antennas may include multiple directional antenna elements.

Abstract: A combined airborne Air Traffic Control Radar Beacon System/Mode-Select (ATCRBS/Mode-S) surveillance system and Traffic Alert and Collision Avoidance (TCAS) collision avoidance system device having common antennas and a switch coupling the common antennas to the relevant functions.

Abstract: A method for removing clutter related frequency components from power spectrums generated from weather radar return signals to provide improved windshear detection capability. Weather radar return signals are synchronously detected and digitized to provide i and q time domain sample sequences. The i and q time domain sample sequences are passed through a window function and then transformed to frequency domain sequences by a Fast Fourier Transform. A power spectrum is generated from the frequency domain sequences. The spectrum is subjected to a Spectral Gaussian Envelope Discrimination (SGED) process in which the spectral envelope is scanned to identify any lobe therein having a slope greater than a predetermined minimum. A first pseudo-Gaussian sigma, calculated from the width and maximum amplitude of any such lobe, is compared with a second pseudo-Gaussian sigma, calculated from known conditions.

Abstract: A radar utilizes an antenna stabilization error correction system to automatically estimate and correct attitude sensor errors in pitch, roll and elevation. The radar system includes an antenna, an antenna positioner, a transmitter receiver, a signal processor, an antenna controller and stabilization processor and the antenna stabilization error correction system. As part of the normal signal processor sub function, ground clutter signals are extracted from the received signals. These signals are the primary input to the antenna stabilization error correction system. Other inputs are received from the signal processor, antenna controller and stabilization processor and an external aircraft radio altimeter. The antenna stabilization error correction system processes the signals and estimates pitch, roll and elevation errors which are passed back to the antenna controller and stabilization processor.

Abstract: A distributed network that compensates for the effects of interelement coupling in a multielement antenna array is inserted between the output of an antenna array and the inputs of a receiver system. Within the distributed network are a plurality of couplers interconnected by transmission lines serving as phase shifters. The coupling factors of the various couplers and the lengths of the transmission lines are selected so as to apply voltage components of specific amplitudes and phase to the antenna ports. The values of the amplitudes and phases of these voltage components are such as to neutralize the components of the voltages at the output of the antenna array which are caused by the spatial couplings between the elements of the antenna array.

Abstract: A direction finding receiving system for use on a protected aircraft in which a signal from an ATCRABS transponder on an intruder aircraft is received has been described incorporating a four element interferometer type antenna array, reversing switches, individual receivers, a phase detector and a processor for processing the outputs of the phase detector. The invention overcomes the problem of correcting for the difference in phase delay of signals passing through the receivers.

Abstract: The invention comprises a weather radar system in which a magnetron transmitter is controlled in frequency by injecting therein a low power locking signal from a stable frequency source. Frequency lock between the source and the magnetron is maintained without requiring injection signals of excessive power by an automatic frequency control (AFC). The AFC determines the frequency and phase error between the injection signal and the magnetron output and adjusts the frequency of the source so as always to be within a narrow band of frequencies centered about the natural frequency of the magnetron. Over the long term, therefore, the frequency of the source will vary by an amount equal to the change in the natural frequency of the magnetron occurring during that time. Over the short term, however, the difference in frequency between the injection signal and the magnetron output is zero, while the phase difference is less than 90.degree..

Abstract: A radar field of interest is divided into cells at a common range but at different angular spacings. The second derivative of the signal intensity of a radar return signal in each range cell is obtained by subtracting the signal intensity in the cell of interest from the signal intensity in the adjacent cell to obtain the first derivative and then subtracting the first derivative thus obtained from the subsequent first derivative. The second derivative is summed with subsequent second derivatives and further summed with the original return signal. The last sum is scaled, raised to an exponential value and again summed with the original return signal. The resultant signals from each range cell are reassembled to form a field of data corresponding to the radar field of interest.

Abstract: In a radar display system wherein radar return signals are received at a first rate and displayed at a second, usually higher rate, each radar return signal is digitized and used to update a main memory comprised of a random access memory so that the main memory contains information related to a plurality of radar return signals arranged therein in a logical order. The main memory information is continuously clocked out for display by an address counter which counts through two complete cycles in a first stage before incrementing a second stage so that the stored information related to each radar return signal is read out for display twice consecutively before the stored information related to the next radar return signal is read out for display.

Abstract: A radar return signal is analyzed by amplitude comparators so as to classify the radar return signal with respect to 2.sup.n -1 threshold levels to thus produce n parallel bits for each classification defining the instantaneous amplitude of the radar return signal. The bits in a given significant bit position (most significant, least significant, etc.) comprise a word which moves through the video storage device serially with respect to bits in the same significant bit position and in parallel with respect to bits in the word comprised of different significance bits. Input buffers in the form of n storage registers are provided, each storage register being associated with a particular bit significance. The bits are entered into their associated storage register at a rate dependent upon the desired radar range. The bits are optionally integrated on a bit-by-bit basis and then entered into a main memory having n circulating storage registers arranged in parallel.