A vehicle communication system and method of improving location services for a user in a vehicle are described. The method includes the steps of: receiving at a backend system a first message from the vehicle based on a determination of a malicious attack associated with global navigation satellite system (GNSS) data received by the vehicle; receiving from a wireless carrier system (WCS) location data associated with a position of the vehicle; providing the location data to the vehicle from the backend system in response to the receipt of the first message; receiving a second message from the vehicle indicating that the malicious attack is no longer viable; and in response to receiving the second message, ceasing to provide the location data from the backend system.

Determining a signal emitter location involves receiving a signal of interest (SOI) at detection devices, generating a time stamp corresponding to the arrival of the SOI at each detection device, and communicating digital data samples and the time stamp to a time-difference of arrival (TDOA) computer system. The TDOA computer system determines a TDOA of the SOI at the detection devices relative to an arrival time at a first one of the detection devices having an earliest time stamp. It determines a first solution to identify the emitter location in accordance with a first TDOA solution method. It evaluates the reliability of the first solution and selectively uses a second solution if the first solution is insufficiently reliable.

It is presented a method for determining whether a portable key device is located in an active area in relation to a barrier. The method is performed in an access control device and comprising the steps of: detecting a first angle of arrival of a wireless signal from the portable key device using a first pair of separated antennas; detecting a second angle of arrival of a wireless signal from the portable key device using a second pair of separated antennas; determining a first pair of directions based on the first angle of arrival; determining a second pair of directions based on the second angle of arrival; determining a position of the portable key device to be where one of the first pair of directions intersects one of the second pair of directions; and determining whether the portable key device is located in the active area based on the position.

It is presented a method for determining whether a portable key device is located in an active area in relation to a barrier. The method is performed in an access control device and comprising the steps of: detecting a first angle of arrival of a wireless signal from the portable key device using a first pair of separated antennas; detecting a second angle of arrival of a wireless signal from the portable key device using a second pair of separated antennas; determining a first pair of directions based on the first angle of arrival; determining a second pair of directions based on the second angle of arrival; determining a position of the portable key device to be where one of the first pair of directions intersects one of the second pair of directions; and determining whether the portable key device is located in the active area based on the position.

Described in detail herein are methods and systems for detecting missing or miss positioned labels. The system can include a portable scanning device to scan machine-readable elements included on labels at a first and second location. The portable scanning device can detect the acceleration and the cumulative change between the first and second location. The portable scanning device or a computing system can determine the distance between the first and second location based on the acceleration data. The computing system can place a data point on a map of an estimated location of the location of the first scan and the location of the second scan.

A dual band radio frequency signal acquisition and source location system, provided with a steerable phased array antenna operable in a first and a second radio frequency band. A digital signal processor electrically connected to the steerable phased array antenna is configured to control steering of an antenna beam of the steerable phased array antenna and apply frequency time division multiplexing to radio frequency signaling in the first and the second radio frequency bands. In particular, the first frequency band may be 2.4 GHz Bluetooth/Bluetooth Low Energy, and the second frequency band may be 900 MHz passive UHF RFID.

A dual band radio frequency signal acquisition and source location system, provided with a steerable phased array antenna operable in a first and a second radio frequency band. A digital signal processor electrically connected to the steerable phased array antenna is configured to control steering of an antenna beam of the steerable phased array antenna and apply frequency time division multiplexing to radio frequency signaling in the first and the second radio frequency bands. In particular, the first frequency band may be 2.4 GHz Bluetooth/Bluetooth Low Energy, and the second frequency band may be 900 MHz passive UHF RFID.

A method, apparatus and RF unit for determining true angles of arrival of a beam received at an antenna array having a pair of antenna elements are provided. In some embodiments, a method includes computing a sum signal based on a sum of signals received from the pair of antenna elements of the antenna array and computing a difference signal based on a first difference of the signals received from the pair of antenna elements of the antenna array. The method also includes computing one of: a ratio of the sum signal to the difference signal; and a second difference between the sum signal and the difference signal. The method also includes determining all possible angles of arrival of the beam based on the one of the ratio and the second difference and then determining the intersection of all the possible angles of arrival for each of the different positions in order to determine the true angles of arrival.

A light source emits a modulated light, and a radio-frequency transceiver disposed therewith emits a radio-frequency signal. A mobile device may receive either or both signals and determine its position based thereon. The light and radio-frequency sources may be disposed in node in a network of said sources, and the nodes may communicate via the radio-frequency transceivers.

An electromagnetic radiation source locating system including an electromagnetic radiation sensor including an antenna configured to detect a radiant energy transmission. A position detector is in communication with the controller and is configured to detect the position of the antenna relative to a reference coordinate system, while an orientation sensor is in communication with the controller and is configured to detect the orientation of the antenna and provide an orientation signal to the controller. A range sensor is configured to detect the distance to an aligned object in the path of a directional vector and provide a distance signal indicative thereof to the controller. An aerial vehicle may be in communication with the controller and configured to drop a marker for guiding navigators to the source of the radiant energy transmission.