Abstract: Apparatus and associated methods relate to detecting cloud conditions from a distance by generating a polarized microwave-frequency electromagnetic pulse and evaluating various reflected wave parameters pertaining to a corresponding cloud-reflected microwave-frequency electromagnetic reflection. Various cloud metrics can be calculated using these collected wave parameters. The microwave-frequency pulses can be scanned over multiple dimensions, using a steered beam arrangement which will lead to the ability to scanning a conical sector of the space in front of the aircraft. These collected multi-dimensional wave parameters can then be used to generate multi-dimensional maps of cloud metrics. Such cloud metrics can include relative velocities of moving cloud conditions in the flight direction, particle density distributions, ice/water ratios, estimates of particle side distributions, etc.

Abstract: Disclosed are physical unclonable functions (“PUFs”) that provide both a hardware timestamp and an encryption key. The timestamp is more accurate than traditional timestamps generated by software calls to the computing device's operating system, while the encryption key can be used for, among other things, securing time-synchronization packets sent across a network. By combining timestamp generation with encryption key generation, the PUFs provide enhanced security while being cheaper to build and to operate than the specialized cryptographic hardware that they replace.

Abstract: Optical positional tracking systems that may be used in virtual reality (VR)/augmented reality (AR) applications are described. Exemplary implementations comprise one or more receivers and one or more transmitters. Exemplary transmitters contains two orthogonal rotors that each emit a fan-shaped laser beam. Each beam is swept as the rotors are spun at constant speed. Exemplary optical receivers can be relatively small, and mounted at convenient locations on the VR display. These receivers consist of small optical detectors that may be mounted on head-mounted VR displays. Exemplary systems determine position by measuring the time at which each swept beam crosses each receiver/detector.

Abstract: A system and process that can be used to determine vehicle attitude with only one navigation receiver. In one embodiment, the antenna of the navigation receiver is driven with a signal that modulates sensitivity in azimuth. The received navigation signal strength is demodulated by the phase at which the antenna is sweeping and a phase angle and a magnitude for the incoming signal are calculated. Using this calculated phase angle, magnitude and antenna characteristics, the location of the user (i.e. the navigation receiver) and the location of the navigation satellite, the attitude of the antenna and hence the user or user vehicle can be determined.

Abstract: A method for calculating vertical trajectory values is provided. The method obtains aircraft performance data for a particular aircraft and atmospheric condition data associated with an air route; calculates a cost-efficient vertical trajectory for the air route, based on the aircraft performance data and the atmospheric condition data, wherein the cost-efficient vertical trajectory comprises a plurality of altitude values for minimizing cost for the particular aircraft during travel of the air route; obtains an altitude consistency threshold; and adjusts the cost-efficient vertical trajectory using the altitude consistency parameter, to create an optimized vertical trajectory for the aircraft route.

Abstract: There is provided a method for positioning of user equipment. The method for positioning of user equipment, includes: receiving, by the user equipment, a signal from an external antenna, the signal being radiated in a cyclic pattern; measuring, by the user equipment, strength of the received signal, characterizing, by the user equipment, the measured strength to form a signal pattern over a time period; and determining a position of the user equipment based on the signal pattern.

Abstract: Methods and systems are provided for monitoring an aircraft. An exemplary method involves capturing, by a computing system at a ground location, a flight tracking image associated with the aircraft that is displayed on a first display device at the ground location, and communicating the captured flight tracking image to the aircraft for display on a second display device onboard the aircraft.

Abstract: Provided is a method of locating a damage source of a wind turbine blade for tracking a damage source location of a blade used in a wind power generator, and more particularly, a method of locating a damage source of a wind turbine blade and an apparatus thereof in a large composite material structure capable of accurately locating a damage source even in a large composite material structure by detecting defects using contour maps written based on elastic wave energy value. The method of locating a damage source of the wind turbine blade according to the present invention can accurately locate the damage source even in the large composite material structure using at least two materials unlike the related art and can use a smaller number of AE sensor than the related art.

Abstract: A method for positioning a node within a wireless sensor network in which each node measures RSSs from its neighboring nodes. Path loss parameters of a channel between a regular node and a neighboring node are first obtained. Distances separating each regular node from its neighboring nodes are then estimated on the basis of the measured RSSs, the allocated path loss parameters. Each distance estimate is further corrected by a systematic bias depending upon the actual sensitivity of the receiver. The positions of the regular nodes are estimated from the distance estimates thus corrected.

Abstract: A system for measuring the radial speed of a moving body in a line of sight determined for a referential position is disclosed. The system includes an emitter assembly for emitting a signal and a referential receiver assembly dedicated to reception of the signal. The emitter assembly is disposed on a first of the elements of a group formed by the moving body and the referential position. The receiver assembly is disposed on a second of the elements of the group. The emitter assembly is able to emit a signal on at least two emission frequencies, where the emission frequencies are separated by a chosen emission frequency gap. The system also includes an analyzer configured to analyze the signal received by the receiver assembly, and to measure the reception frequency gap separating the signal reception frequencies to calculate the radial speed of the moving body according to a function of the reception frequency gap and emission frequency gap.

Abstract: There is provided a method for positioning of user equipment. The method for positioning of user equipment, includes: receiving, by the user equipment, a signal from an external antenna, the signal being radiated in a cyclic pattern; measuring, by the user equipment, strength of the received signal, characterizing, by the user equipment, the measured strength to form a signal pattern over a time period; and determining a position of the user equipment based on the signal pattern.

Abstract: A method and apparatus for estimating location of wireless stations in a wireless communication network are provided. An estimation of a bearing angle of a wireless station from a reference point of a multi-beam antenna pattern is made based on a plurality of beaming angles of a multi-beam antenna pattern and a received signal property, at the wireless station, of each of a plurality of wireless signals transmitted on respective beams of the multi-beam antenna pattern for each of the plurality of beaming angles.

Abstract: A system for measuring the radial speed of a moving body in a line of sight determined for a referential position includes an emitter assembly for emitting a signal and a referential receiver assembly dedicated to reception of said signal. The emitter assembly is disposed on a first of the elements of a group formed by the moving body and the referential position. The receiver assembly is disposed on a second of the elements of the group. The emitter assembly is able to emit a signal on at least two emission frequencies, said emission frequencies being separated by a chosen emission frequency gap. The system includes a means for analyzing the signal received by the receiver assembly, to measure the reception frequency gap separating the signal reception frequencies to calculate the radial speed of the moving body according to a function of the reception frequency gap and emission frequency gap.

Abstract: There is provided a method for identifying, at the moment of verification, the situation of a threat to a protected ground, airspace and/or sea limits by an approaching ground vehicle, aircraft or sea-going vessel. The method includes an authorized driver/pilot/captain to select first state in which the vehicle, aircraft or sea-going vessel is not considered to present a threat and a second state in which the vehicle, aircraft or sea-going vessel is considered to present a threat. The method further provides entering the first and second PIN codes into a smart card for generating a One Time Indicia (OTI) for each of the PIN codes and disclosing the state associated with each of the first and second OTI codes to at least one control center. Upon the control center receiving an OTI code, the control center obtains positive identification of the driver/pilot/captain and the degree of the threat that the vehicle, aircraft or sea-going vessel presents.

Abstract: A positioning method for a sensor node is provided, and the method includes steps of: providing a first antenna having a first omnidirectional radiation pattern on a first plane; rotating the first antenna about an axis substantially parallel to the first plane; transmitting a wireless signal while the first antenna rotates about the axis for every a predetermined central angle; receiving the wireless signal at the sensor node; obtaining Received Signal Strength Indications (RSSIs) of the respective wireless signals; and determining a location of the sensor node according to the RSSIs.

Abstract: An attitude system that includes a radiating means which moves predeterminately through three-dimensional space, such that a cyclic Doppler is superimposed upon a transmitted signal; receiving this transmitted signal through a receiving means which moves predeterminately through three-dimensional space, such that a cyclic Doppler is superimposed upon the received signal; analyzing the movement of the receive means in relation to the radiating means by interpreting the received cyclic Doppler; and determining attitude based on the interpreted Doppler. Or alternatively, adjusting the movement of the receive means in three-dimensional space so the superimposed cyclic Doppler is minimized on the received signal and; determining attitude based on the adjustment required to bring the receive means and radiating means into an alignment.

Abstract: A method and apparatus for encoding information in a reference beacon signal for use in a time-difference-of-arrival/frequency-difference-of-arrival (TDOA/FDOA) geolocation system. Information is encoded in the reference beacon signal using variations in the times and frequencies of sequential reference signal transmissions. The encoded information may include an identifier associated with the transmitter of the reference beacon signal. A geolocation system receiving the reference beacon signal can thus differentiate it from non-cooperative target emissions as well as from other reference beacon signals.

Abstract: A phased array antenna system includes an RF front end, a radome, and an optical calibrator embedded in the radome for enabling in-situ calibration of the RF front end. The optical calibrator employs an optical timing signal generator (OTSG), a Variable Optical Amplitude and Delay Generator array (VOADGA) for receiving the modulated optical output signal and generating a plurality of VOADGA timing signals, and an optical timing signal distributor (OTSD). The in-situ optical calibrator allows for reduced calibration time and makes it feasible to perform calibration whenever necessary.

Abstract: A method determines the position of a mobile object by using at least one radio signal having a rotating transmission characteristic with at least one reference station. The relation between the orientation of the transmission characteristic and reference events is communicated to the mobile object. The orientation of the transmission characteristic and the relative position with respect to the reference station can be determined from the reference event.

Abstract: A system and a method of locating a co-operative transceiver in an indoor location by setting up multiple transmitting beacons outside of a building in which the transceiver is located. Information at the transceiver, such as time-of-arrival (TOA) or time-difference-of-arrival (TDOA) of the first-to-arrive signals originating from the external beacons, is relayed back to a processing centre. The angle-of-transmission (AOT) is then determined for the first-to-arrive signals, the only ones with a potential for line-of-sight signals, as well as any arriving reflected signals. Synthetic Doppler, by revolving the transmitting antenna, is used to distinguish between a line-of-sight received signal in order to accurately determine the location of the transceiver.

Abstract: A method for calculating the phase reception pattern of an antenna system utilized in attitude determination is disclosed. The antenna system is disposed on a platform (or rate table) that rotates about a single, fixed axis at a constant rate as incoming signals from one or more satellites are received, thereby revolving the antennas about the axis. Information collected from the satellite signals is utilized to calculate a differential phase map (phase measurement error correction map) for the antenna system. The rate of rotation of the table is approximately known, and small variations in the rotation rate may be compensated. The baseline vector connecting two or more antennas is preferably approximately perpendicular to the axis of rotation of the platform. Phase measurement data is collected and may be processed off-line to compute a phase measurement correction map. Attitude calculations may be compensated with the determined differential phase measurement correction map.

Abstract: A radio direction finder based on the simulated Doppler frequency shift principle is disclosed that is applicable to FSK encoded pulsed transmissions. Typical applications include tracking of stolen vehicles or shipped package tracking. During FSK decoding, all antenna elements of the antenna array are turned on in a non-rotating mode thus eliminating error due to the simulated antenna rotation modulation while providing enhanced gain for the FSK decoder circuit. After decoding a suitable FSK signal, a virtual antenna rotation is enabled, and the bearing is measured during the time interval when the transmitter is only broadcasting a carrier wave.

Abstract: This is a Mode S radio frequency transmission system with coordinated use of a rotating directional antenna and omnidirectional antennas. A software-implemented prefilter both processes messages destined for aircraft equipped with Mode S datalink capable transponders, and prevents any uplink message transmission to a transponder from coinciding with the once-per-scan surveillance interrogation from the rotating antenna as well as any datalink interrogations specified for transmission through the rotating antenna.

Abstract: Methods and systems for determining a position and an orientation utilize a radio frequency signal transmitted from an effective source location which moves along a first closed, non-planar path. The closed, non-planar path has a plurality of local extreme points with respect to a predetermined axis. The radio frequency signal is received at an effective receiving location which may, optionally, move along a second closed, non-planar path. A phase signal representative of the phase of the received radio frequency signal is detected. The phase signal is filtered and processed to form at least one signal quantity representative of elevation, bearing, and/or orientation.

Abstract: A stacked Yagi phased array is located within a foil-shaped enclosure that is connected to a rotary joint which allows rotation of the antenna over 360.degree. in azimuth. The radar is normally stored within the equipment bay of an aircraft and is deployed therefrom when radar surveillance by the aircraft is desired. When the antenna is stored, aircraft drag is reduced and radar signature is low. The combination of mechanical and electronic scan permits increased search in critical sectors of interest and allows skipping of other sectors. The rotary joint of the invention requires no RF power or analog signals to pass through it.

Abstract: A passive surveillance method and system, capable of operation in conjunction with both non synchronous and synchronous pulse pattern rotating ground radars. Received signal scan modulated pulses are deinterleaved and correlated with a previously selected repetitive portion of an interrogation signal source base pulse pattern. A single receiver channel, sequential lobe on receive only (LORO) direction finding antenna is employed in the system to modulate received signals to extract target object relative bearings for the correlated signals. The system makes use of all available data to determine the best estimate of the target object position.

Abstract: A system for measuring distances between a central location and any number of remote locations. A transmitter at the central location radiates one or two rotating beams which rotate at an angular velocity which need not be determined. Specially placed sensors at a remote location sense the passage of the beam or beams and allow the accurate determination of the distance between the transmitter and the sensors without the need to measure and/or communicate the angular velocity of rotation of the transmitter signals.

Abstract: The range from which a collision avoidance system at an Own station can receive SSR interrogations and reply messages from Other stations, is extended by utilizing P2 pulses for timing TOA measurement in the event P1-P3 pulse pairs are unavailable from the scanning main beam or its side lobes. The amplitude of the P2 pulses in the SLS radiation pattern being greater than the P1-P3 side lobes of the main beam over an angular sector of about 60.degree. centered on the main beam can insure reception of P2 pulses at much greater ranges than P3 pulses contained in the main beam side lobes can be reliably received. Using P2 timing, interlaced Mode A and Mode C reply messages contained in a main beam burst reply sequence are separated into two "families" of TOAs, the Mode C (altitude) TOAs always being longer than the Mode A TOAs by 13 .mu.sec. A "true" TOA is obtained by subtracting an appropriate time period from the TOA of each family, from which identity, altitude and range information is readily derived.

Abstract: Multiple vehicles located within a predefined search space are located and tracked using at least two spaced-apart transmitters. Each transmitter can broadcast an omnidirectional initialization signal and a positioning signal having a null or break in its wavefront. By rotating the positioning signal, the null will sweep the predefined search space and by detecting both the initialization signal and the null in the positioning signal, the position of each vehicle can be determined. In the preferred embodiment, the locational information from each vehicle is collected at a central location, typically in a data acquisition system or controller. In the particularly preferred embodiment, the locational information is further relied on to provide for command information for feedback control of the vehicles.

Abstract: A radio frequency emitter transmits pulses in a regular swept beam pattern. As a result of this regular pattern, the angles of transmission of the pulses can be inferred. Intervisibility data of terrain points in a region around an observation point are stored in computer memory. At the observation point, measurements are made of the times of arrival of a plurality of terrain point reflections of a single pulse transmitted by the emitter. These measurements are repeated for a plurality of pulses transmitted by the emitter. In a computer, a comparison is made of the terrain points of reflection calculated from the measured times of arrival for assumed emitter locations with the stored intervisibility data of terrain points.

Abstract: Disclosed is a system for aligning elements in azimuth, in particular guns of artillery batteries. A prior system of this type uses an omnidirectional xenon beacon which produces pulses to indicate rotation of a reference unit, a double pulse indicating a reference director. A receiver counts pulses until it detects a directional laser beam from the reference unit, the number of pulses given a reading of what is known as a reciprocal bearing. The xenon and laser pulses are optically separated in the receiver. The prior system is not as reliable as desired, mainly because of scintillation effects. The present invention overcomes this problem by identifying different pulses by the pattern of their arrival times. A detector unit generates and stores numbers each having a magnitude proportional to their time of arrival. The numbers are processed by a microprocessor to determine the angle through which the laser beam travels between a reference direction and the direction of the detector unit.

Abstract: A method for calculating vertical trajectory values is provided. The method obtains aircraft performance data for a particular aircraft and atmospheric condition data associated with an air route; calculates a cost-efficient vertical trajectory for the air route, based on the aircraft performance data and the atmospheric condition data, wherein the cost-efficient vertical trajectory comprises a plurality of altitude values for minimizing cost for the particular aircraft during travel of the air route; obtains an altitude consistency threshold; and adjusts the cost-efficient vertical trajectory using the altitude consistency parameter, to create an optimized vertical trajectory for the aircraft route.