Abstract: Techniques and mechanisms to transmit signals with an antenna array. In an embodiment, a first signal is received at a first input of the first antenna while a second signal is received at a second input of the second antenna. A difference in phase differentials—the phase differentials each between the first signal and the second signal—results from propagation of the first signal and the second signal in the antenna array and from a difference between respective configurations of the first antenna and the second antenna. Each of the first antenna and the second antenna has respective emitters distributed along the length thereof. In another embodiment, the first antenna and the second antenna have different respective dielectric structures or different respective distributions of emitters.

Abstract: A positioning system and method for a monorail train are disclosed. The system includes: a first beacon, laid on one side of an up-going rail; a second beacon, laid on one side of a down-going rail, the first beacon and the second beacon being laid asymmetrically; a first beacon antenna and a second beacon antenna, the first beacon antenna being provided at a front carriage of the monorail train, the second beacon antenna being provided at a rear carriage of the monorail train, and the first beacon antenna and the second beacon antenna being provided on two opposite sides of the monorail train; and a positioning device, configured to acquire beacon data read by the first beacon antenna and beacon data read by the second beacon antenna and to determine a running direction and position information of the monorail train according to the beacon data read by the first beacon antenna and the beacon data read by the second beacon antenna.

Abstract: Methods and systems for location determination are described herein. An example implementation may involve receiving signals from a set of satellites to determine a general location of a receiver. After receiving a signal from a satellite, the receiver may-determine an angle of reception that indicates an orientation of the satellite relative to the receiver. The receiver may further obtain topography information for the general location that indicates the positions and elevations of features (e.g., buildings) at the general location. For instance, the receiver may use elevation maps or sensors to determine the topography information. Using the topography information and determined angles of receptions, the receiver may identify any signals that reflected off a feature prior to reaching the receiver. As a result, the receiver may determine and use the reflected path traveled by a reflected signal to refine the general location of the receiver.

Abstract: Global navigation satellite system (GNSS) radio frequency signals broadcast from geo-stationary satellites 20,000 km above the earth when received by GNSS receivers are fundamentally weak. Accordingly, these GNSS receivers are vulnerable to accidental and deliberate interference from a range of manmade sources as well as natural sources. Existing anti-jamming technologies such as controlled reception pattern antennas, adaptive antennas, null-steering antennas, and beamforming antennas etc. are expensive and incompatible with many lower cost and footprint limited applications. However, in many applications the GNSS antenna is mounted upon a fixed or mobile element such that accidental and intentional jammers tend to be in the plane of the antenna or below it. Accordingly, there are presented designs and techniques to improve the anti-jamming or interference performance of GNSS receivers by further reducing the responsivity of the GNSS receiver to signals in-plane or below the plane of the antenna.

Abstract: A communication apparatus calculates information about a position of the communication apparatus based on a GPS radio wave and registers the calculated information about the position as an installation position of the communication apparatus when a measured strength of the GPS radio wave is equal to or stronger than a predetermined strength, when the measured strength of the GPS radio wave is equal to or stronger than the predetermined strength, periodically calculates the information about the position of the communication apparatus based on the GPS radio wave or the like, uses the calculated information of the position as a current position of the communication apparatus, compares the current position of the communication apparatus with the registered installation position of the communication apparatus.

Abstract: A phase adjusting circuit is provided, including a signal generation circuit receiving a frequency adjusting signal and generating a reference signal having a frequency corresponding to the frequency adjusting signal; a first path receiving the reference signal and providing a first signal; a second path receiving the reference signal and providing a second signal, and time for the reference signal passing through the second path is different from time for the reference passing through the first path; a phase shifter disposed on the first path or the second path and shifting a phase of the reference signal based on a phase adjusting signal; a phase difference detection circuit detecting a phase difference between the first and the second signals; and an adjusting signal generation circuit generating the frequency adjusting signal and the phase adjusting signal based on the phase difference so that the phase difference becomes a target value.

Abstract: A method of locating a coal-rock main fracture by an electromagnetic radiation from a precursor of a coal-rock dynamic disaster is provided. At least four groups of three-component electromagnetic sensors are arranged in the underground tunnels, and each group of sensors includes three directive antennas for receiving electromagnetic signals orthogonal to each other. The electromagnetic signals are collected by a monitoring host. The signals are ensured to be received by different sensors synchronously via an atomic clock. The direction of the magnetic field line is determined by performing a vector superposition on strengths of the three-component electromagnetic signals of each group of sensors. The planes of electromagnetic wave propagation perpendicular to the direction of the magnetic field line are determined accordingly. The location of the coal-rock fracture is determined by the intersection point of the planes of electromagnetic wave propagation determined by the multiple groups of sensors.

Abstract: An apparatus includes an antenna assembly including an antenna configured to receive a signal and, based on the received signal, generate a first linearly polarized signal at a first feed point and a second linearly polarized signal at a second feed point; and a switching circuit configured to periodically switch between the first feed point and the second feed point to select a polarized signal between the first and second polarized signals at a point in time based on a switching signal.

Abstract: Differential ranging measurements are formed using first ranging measurements from reference GNSS receivers and second ranging measurements from GNSS receivers on a rover, the first and second ranging measurements received from a plurality of GNSS satellites. A main navigation solution and a main protection level (PL) set are computed based on the differential ranging measurements. Ionospheric threat scenarios associated with experiencing severe ionospheric gradients to one or more of the plurality of GNSS satellites are determined. A supplemental navigation solution and a corresponding supplemental PL set for each of the plurality of ionospheric threat scenarios are computed. A maximum PL set is selected based on the main PL set and the supplemental PL sets to form a final PL set that protects the main solution against nominal navigation threats and severe ionospheric threats.

Abstract: An interrogation device, for locating a wireless device, includes a receiver and digital processing circuitry. The receiver includes one or more receiver stages having adjustable gains, and is configured to receive from the wireless device a signal that carries a packet including a direction-finding field, wherein, during reception of the direction-finding field, multiple different temporal sections of the received signal traverse different wireless channels due to switching among different antennas in the interrogation device or in the wireless device and thus have multiple different received-signal levels. The digital processing circuitry is configured, based on the multiple received temporal sections of the signal during reception of the direction-finding field, to (i) adapt the adjustable gains of the receiver stages and (ii) estimate a position of the wireless device.

Abstract: The present invention relates to a georeferencing certification method actuated by means of a central unit with one or more GNSS sensors and one or more mobile devices which request the georeferencing. The mobile device will collect the information monitored by the GNSS sensor installed on the mobile device and send it to the central unit, which will compare the information received with that which it has acquired through its relative GNSS sensors. The result of the comparison will authorise, or not, the unit to issue the georeferencing certification.

Abstract: A virtual reference station switching method includes obtaining networking change information of a reference station network, obtaining prediction information based on the networking change information of the reference station network, where the prediction information includes a reference station combination used to calculate a virtual reference station of a mobile station is switched from a first reference station combination to a second reference station combination, obtaining a first virtual reference station through calculation based on the first reference station combination, and obtaining a second virtual reference station through calculation based on the second reference station combination, and providing at least one of first virtual reference station information or second virtual reference station information to the mobile station.

Abstract: A system and method for discriminating and mitigating spoofing signals incoming to a satellite navigation system. Beam steering techniques are used to steer a null toward a legitimate satellite signal that is being spoofed. The spoofing signal is then tracked and its angle of arrival measured. A null is steered toward the measured angle of arrival of the spoofing signal, and the spoofing signal is confirmed by determining if there is a signal remaining with nulls on both the legitimate satellite signal and the spoofing signal. The null toward the legitimate satellite signal is then replaced with unity gain.

Abstract: A phased array antenna system includes a plurality of radio frequency (RF) tile sub-arrays. Each RF tile sub-array includes a multiplicity of RF elements, a tile control integrated circuit, a multiplicity of RF integrated circuits and a configuration storage device. The configuration storage device stores data including calibration and configuration information that is unique to the RF tile sub-array and the tile control integrated circuit. The multiplicity of RF integrated circuits, the multiplicity of RF elements, and the configuration storage device are disposed on a single associated RF tile sub-array. The system also includes an antenna controller configured to process data for steering or tracking one or more RF beams by the multiplicity of RF elements. The calibration and configuration information that is unique to the RF tile sub-array is downloaded from the configuration storage device through the tile control integrated circuit to an RF element compensation table.

Abstract: A method and apparatus for beamforming in a wireless communication system are provided. The method of supporting beamforming in a wireless communication device includes detecting a direction change of the wireless communication device while communicating with a peer device. The method of supporting beamforming in a wireless communication device also includes adjusting a beam direction for communication with the peer device based on information indicating a direction change of the wireless communication device.

Abstract: Systems and methods are provided for wide scan phased array fed reflector systems using ring-focus optics to significantly improve the scan volume of such systems. The subject system includes a reflector having a focal plane and a parabolic curvature configured to receive electromagnetic radiation having a first gain and provide reflected electromagnetic radiation having a second gain greater than the first gain that collimates into a focal ring. The subject system includes a feed array having feed elements positioned about the focal ring, in which each feed element is configured to receive the reflected electromagnetic radiation from the reflector and collimate the reflected electromagnetic radiation into a scanned beam for scanning an annular region. In some aspects, the feed array is centered on the focal ring such that at least one feed element overlaps with the focal ring and remaining feed elements are non-overlapping with the focal ring.

Abstract: A system and method for generating a set of GNSS corrections using a GNSS corrections model comprising a Gaussian process.

Abstract: A direction finding system for radio direction finding of a target emitting at least one signal is described. The direction finding system comprises at least one receiver unit, at least one antenna assigned to the at least one receiver unit and a central processing unit connected to the at least one receiver unit. The at least one receiver unit is configured to measure an absolute receiving power or a relative receiving power of the at least one signal emitted by the target. The central processing unit is configured to determine the power level of the respective power received by the at least one receiver unit. The central processing unit is further configured to determine interpolated constant power contours in order to locate the target. In addition, a method for radio direction finding of a target emitting electromagnetic at least one signal is described.

Abstract: A deceiving signal detection system includes a first antenna, a second antenna, and a signal processor. The first antenna is configured to receive at least four radio wave signals. The signal processor determines that the radio wave signals are the deceiving signals by determining that a relative positional relation between the first antenna and the second antenna calculated on a basis of the radio wave signals deviates from an actual relative positional relation between the first antenna and the second antenna by more than a predetermined amount, and also determines whether an orientation of the aircraft determined based on positions of the first antenna and the second antenna matches an orientation of the aircraft calculated based on an inertial navigation system.

Abstract: An apparatus for determining signal strength data within at least one allocated GNSS frequency band is provided. The apparatus includes a GNSS antenna. The GNSS antenna receives signals within the allocated GNSS frequency band. The apparatus further includes receiving circuitry. The receiving circuitry is for demodulating the received signals. The apparatus further includes a processor and memory for storing instructions, executable by the processor. The instructions include instructions for generating signal strength data for the received signals within the GNSS allocated frequency based on the demodulated signals, and for determining a position for a point of interest based upon the demodulated signals. Included in the apparatus is a display screen for displaying a graphical representation of the signal strength data of at least a portion of the at least one GNSS allocated frequency band.