Abstract: A direction finding antenna system for determining the relative bearing of a second aircraft from a first aircraft in conjunction with Distance Measuring Equipment (DME). The system includes a first antenna and a second antenna located on a top surface of the first aircraft, spaced apart along a first axis, as well as a third antenna and a fourth antenna located on a bottom surface of the first aircraft, spaced apart along a second axis orthogonal to the first axis. The system further includes a transmitting, receiving, and processing system coupled to the first, second, third, and fourth antennas, wherein the transmitting, receiving, and processing system is configured to transmit DME interrogations, receive DME replies, and process the DME replies to determine the relative bearing of the second aircraft from the first aircraft.

Abstract: Methods of operating a satellite navigation system (SNS) receiver in a portable electronic device according to some embodiments include determining the presence or absence of a low frequency signal associated with power distribution lines, and disabling the SNS receiver in response to detecting the low frequency signal associated with power distribution lines. The methods may further include detecting weakening of a satellite navigation signal, and determining the presence or absence of a low frequency signal associated with power distribution lines may be performed in response to a detected weakening of the satellite navigation signal. Related devices are also disclosed.

Abstract: A system to determine a direction of arrival of each of a plurality of constituent signals of a superimposed wave includes a tripole radio antenna, a sampling unit, a frequency determining unit, an amplitude and phase determining unit, and a direction determining unit. The sampling unit is configured to periodically sample an output of the tripole radio antenna to generate at least two samples. The frequency determining unit is configured to determine frequencies for each dimension of the constituent signals by performing a unitary matrix pencil method on the at least two samples. The amplitude and phase determining unit is configured to determine x, y, z amplitudes and x, y, z phases for each constituent signal using the determined frequencies. The direction determining unit is configured to determine a direction of arrival for each of the constituent signals from the determined frequencies, amplitudes, and phases.

Abstract: An electronic device for decoding a navigation data by using a phase angle variation and a method thereof are described, which includes the following steps. A phase angle difference between the first phase angle of the first navigation data and the second phase angle of the second navigation data from a satellite signal is calculated. When the phase angle difference is greater than 90 degrees, the first navigation data and the second navigation data are determined to have opposite signs. The second navigation data according to the first navigation data and the result is determined. Therefore, each data is interpreted through directly comparing whether the phase angle difference with the previous data is greater than 90 degrees or not, so that the correct rate in decoding the navigation data is increased.

Abstract: A slice set for a specific period of time is acquired from a storage area of a memory which is a ring buffer while changing the read position, and the signal strength total value of each slice set is calculated. The signal strengths of the slices included in the maximum strength slice set and the signal strengths of the slices preceding or subsequent to the maximum strength slice set are calculated, and the final signal read position is determined based on a read offset of the maximum strength slice. A GPS satellite signal is acquired and tracked based on the slice read from the determined signal read position, and a specific positioning process is performed.

Abstract: The present invention provides a global navigation satellite system (GNSS) based positioning system and tracking method using a data communication network. When a GNSS-based positioning device is connected to a data communication network, the positioning device transfers the GNSS digital data and supplementary information used for additional performance improvement to a location tracking server through the data communication network, the location tracking server calculates a position of the positioning device with improved receiver sensitivity based on plentiful computational resources available at the location tracking server. Thus, the positioning device may find its location of even in very poor signal condition. Further, the present invention provides a positioning system and method using a data communication network, which may achieve time synchronization when there is a need to extract not only position information but also absolute timing information.

Abstract: A surveillance system is disclosed. In some embodiments, the surveillance system may include at least one controller configured to receive information data from at least one upstream information source and to control operation of at least one controllable downstream information source based, at least in part, on the information data. A surveillance method also is disclosed. In some embodiments, the method may include analyzing screening data, obtaining information data, and reanalyzing the screening data based, at least in part, on the obtained information data.

Abstract: Described herein are systems and methods that eliminate the need for costly and complex switching networks for routing channelized data between antenna elements and beamformers. In one aspect, a beamforming system comprises a beamformer for each antenna element of an antenna array, in which the beamformers for the different antenna elements are arranged in parallel. The beamforming system also comprises a combiner that combines the outputs of the beamformers into a single beam. In one aspect, the beamformers of antenna elements that do not contribute to a desired beam output zeros to the combiner, which when added to the subbeams of the other beamformers have no affect of the final beam. In another aspect, operations (e.g., multiplication, memory reads) of each beamformer that does not contribute to a desired beam may be turned off to conserve power.

Abstract: A blockage detection system and method for use in a sensor such as a side object detection (SOD) sensor in an automotive radar system is described. The sensor emits signals and receives return signals (i.e. reflected signals) from a passing object. If the passing object is within a virtual detection zone, the sensor uses the information from the passing object to determine if a blockage condition exists in the sensor. The technique utilizes statistics related to the passing object to determine whether a blockage condition exists within the sensor. In one embodiment, a SOD sensor mounted in a first vehicle uses information from a second passing vehicle (e.g. radar return information) to determine whether a blockage condition exists within the SOD sensor itself.

Abstract: To maintain the safety by avoiding deterioration in the positioning accuracy through making SBAS satellite navigation data used in a ground system and in an airborne system consistent by employing GBAS. The system includes: a ground system which estimates errors contained in ranging signals received from the navigation satellites, and formats and transmits correction information for correcting the estimated errors; and an airborne system which calculates differential GPS positioning based on the ranging signals received from the navigation satellites and the formatted correction information, and displays a displacement from a regulated route. The ground system notifies update, when SBAS satellite navigation data used for generating the correction information is updated, by adding information regarding update of navigation data to the correction information.

Abstract: An aircraft weather radar system includes an input for receiving data associated with weather radar returns received by an antenna. The aircraft weather radar system further includes processing electronics for performing a routine to analyze radar returns associated with terrain. The processing electronics are configured to determine atmospheric refraction characteristics based on a range and/or an angle to terrain. The routine is based on the determination of atmospheric refraction characteristics.

Abstract: An apparatus a transmitter section, a receiver section, and a processing module. The transmitter section transmits a plurality of high carrier frequency beamformed signals in a loop manner until a desired number of signals has been transmitted. The receiver section receives the plurality of high carrier frequency beamformed signals and determines reception properties of the plurality of high carrier frequency beamformed signals. The processing module determines at least one of: reflection, absorption, refraction, and pass through based on the reception properties. The processing module then distinguishes an animate entity from an inanimate entity based on the at least one of the reflection, absorption, refraction, and pass through. The processing module then determines position of the animate entity within a given physical area.

Abstract: A method for determining that a GPS receiver is located within a predetermined geofence volume. An embodiment of the invention includes the steps of receiving global positioning system signals from a plurality of GPS satellites; calculating a solution set of possible receiver positions from the global positioning signals; determining whether any portion of the solution set of receiver positions is within the geofence volume; and determining that the receiver is outside the geofence volume if no portion of the solution set of receiver positions is within the geofence volume. The concept of exclusion space is introduced and used in methods for determining the probability that a receiver is within a geofence volume.

Abstract: A new approach to radar imaging is described herein, in which radar pulses are transmitted with an uneven sampling scheme and subsequently processed with novel algorithms to produce images of equivalent resolution and quality as standard images produced using standard synthetic aperture radar (SAR) waveforms and processing techniques. The radar data collected with these waveforms can be used to create many other useful products such as moving target indication (MTI) and high resolution terrain information (HRTI). The waveform and the correction algorithms described herein allow the algorithms of these other radar products to take advantage of the quality Doppler resolution.

Abstract: A process for detecting the harmonic motion characterizing a desired target. An exemplary method includes generating a radar image of the target utilizing a pulse doppler radar. A plurality of matched filter signals are generated in the receiver, each matched filter signal corresponding to a doppler profile of harmonic acceleration for the desired target. The matched filter signals are generated by an array of matched filters, with each matched filter signal corresponding to a predetermined doppler profile. The received radar image is then correlated to the matched filter signals to detect the desired target.

Abstract: Method of high-resolution direction finding to an arbitrary even order, 2q (q>2), for an array comprising N narrowband antennas each receiving the contribution from P sources characterized in that the algebraic properties of a matrix of cumulants of order 2q, C2q,x(l), whose coefficients are the circular cumulants of order 2q, Cum[xi1(t), . . . , xig(t), xiq+1(t)*, . . . , xi2q(t)*], of the observations received on each antenna, for cumulant rankings indexed by l, are utilized to define a signal subspace and a noise subspace.

Abstract: A system and method for implementing a maximum likelihood estimator for making a joint estimation of range, range rate, and acceleration of a target utilizing a pulse doppler radar. The MLE of target motion parameters are determined by keystone processing a baseband signal, and generating a first estimate of the motion parameters based on the processed signal. The first estimate is utilized to set up sampling intervals for the performance of a coarse search. Then a fine search is performed using Newton's method to determine the MLE.

Abstract: A transponder-based beacon transmitter system in an unmanned aerial vehicle is provided. The transponder-based beacon transmitter system comprises a global positioning system interface communicatively coupled to receive position information indicative of a current location of the unmanned aerial vehicle, a message formatter communicatively coupled to the global positioning system interface, and a transponder-based beacon transmitter. The message formatter formats vehicle identification of the unmanned aerial vehicle and the position information indicative of the current location of the unmanned aerial vehicle into an automatic dependent surveillance broadcast mode-select squitter message. The message formatter operates in one of a military mode, a National Airspace System mode, and a combined military/National Airspace System mode. The transponder-based beacon transmitter transmits the automatic dependent surveillance broadcast mode-select squitter messages from the unmanned aerial vehicle.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining, that signalA contains the same unknown signal that is contained in signalB.

Abstract: Methods and systems for reducing a leakage component of a received-signal are disclosed. A transmit antenna of a radar system transmits a transmit-signal including a transmit component. A receive antenna of the radar system receives a received-signal including a leakage component and a target component. The received-signal corresponds to the transmit-signal. An overlap determination is made to determine whether the target component overlaps the leakage component and/or is received during a time when the leakage component is expected to be received. If overlap exists, a reduction leakage component (e.g., a previously determined reduction leakage component) is subtracted from the received-signal so as to produce a modified received-signal, the modified received-signal including the target component and substantially excluding the leakage component.