A location tracking system includes a first plurality of signal receiving and transmitting devices, the members of the first plurality each include an RF transceiver, sound receivers and sound emitters. A second plurality of signal transmitting units, the members of the second plurality each include at least an RF transceiver and a sound emitter. A system control element in communication with the members of the first plurality wherein the control element determines the locations of members of the second plurality based, at least in part, on information received from members of the first plurality.

A location tracking system includes a first plurality of signal receiving and transmitting devices, the members of the first plurality each include an RF transceiver, sound receivers and sound emitters. A second plurality of signal transmitting units, the members of the second plurality each include at least an RF transceiver and a sound emitter. A system control element in communication with the members of the first plurality wherein the control element determines the locations of members of the second plurality based, at least in part, on information received from members of the first plurality.

A receiving apparatus (7) that can estimate a motion-induced frequency shift in a received signal comprises a processing system (205) and a receiver (204) configured to receive a signal comprising one or more instances of a transmitted signal. The processing system (205) is configured to generate data representative of a plurality of impulse response functions by deconvolving the received signal with each of a plurality of templates representative of the transmitted signal shifted in frequency by a different respective frequency shift. The processing system (205) is further configured to evaluate a signal-to-noise measure for each of the plurality of impulse response functions, and to identify an impulse response function of the plurality of impulse response functions for which the signal-to-noise measure satisfies a peak criterion.

A receiving apparatus (7) that can estimate a motion-induced frequency shift in a received signal comprises a processing system (205) and a receiver (204) configured to receive a signal comprising one or more instances of a transmitted signal. The processing system (205) is configured to generate data representative of a plurality of impulse response functions by deconvolving the received signal with each of a plurality of templates representative of the transmitted signal shifted in frequency by a different respective frequency shift. The processing system (205) is further configured to evaluate a signal-to-noise measure for each of the plurality of impulse response functions, and to identify an impulse response function of the plurality of impulse response functions for which the signal-to-noise measure satisfies a peak criterion.

Apparatuses and methods are described herein for identifying an Unmanned Aerial Vehicle (UAV) by a central server connected to a first detection device and a plurality of detection devices, including, but not limited to, receiving, by the central server, information related to the UAV from the first detection device, selecting, by the central server, a second detection device from a plurality of detection devices connected to the central server, and sending, by the central server, the information to the second detection device.

Apparatuses and methods are described herein for identifying an Unmanned Aerial Vehicle (UAV) by a central server connected to a first detection device and a plurality of detection devices, including, but not limited to, receiving, by the central server, information related to the UAV from the first detection device, selecting, by the central server, a second detection device from a plurality of detection devices connected to the central server, and sending, by the central server, the information to the second detection device.

Provided is a spatial position calculation device that calculates a position of a measurement target in a space with high accuracy even when the measurement target moves at a high speed. Included are a transmission unit 1, 2 or 3 that transmits at a predetermined time interval a modulated sound signal obtained by modulating an original sound signal, a reception unit 4 that receives the modulated sound signal, a calculation unit 5 that calculates spatial position coordinates of either the transmission unit or the reception unit, or a distance from the transmission unit to the reception unit based on an arrival timing of the modulated sound signal to the reception unit, the arrival timing being obtained from cross-correlation calculation between a reference signal generated from the modulated sound signal and a reception signal of the reception unit, and a magnification change unit 47 that changes a magnification in a time direction of the reference signal or the reception signal.

Provided is a spatial position calculation device that calculates a position of a measurement target in a space with high accuracy even when the measurement target moves at a high speed. Included are a transmission unit 1, 2 or 3 that transmits at a predetermined time interval a modulated sound signal obtained by modulating an original sound signal, a reception unit 4 that receives the modulated sound signal, a calculation unit 5 that calculates spatial position coordinates of either the transmission unit or the reception unit, or a distance from the transmission unit to the reception unit based on an arrival timing of the modulated sound signal to the reception unit, the arrival timing being obtained from cross-correlation calculation between a reference signal generated from the modulated sound signal and a reception signal of the reception unit, and a magnification change unit 47 that changes a magnification in a time direction of the reference signal or the reception signal.

Disclosed is a method for locating a portable device giving “hands free” access to a vehicle, by a location device intended to be installed in the vehicle, the portable device communicating with the location device by ultra high frequency waves, the invention consisting at each transmission of an ultra high frequency signal by the location device: of simultaneously transmitting by the location device at least one ultrasonic signal, intended for the portable device; of measuring a delay between a first time of reception of the ultra high frequency signal and un second time of reception of the ultrasonic signal by the portable device; of determining a distance between the portable device and the location device on the basis of the delay thus measured. Also disclosed is a location device and a corresponding portable device.

A method for determining position of an aircraft with reference to a location on the ground includes transmitting an acoustic signal from a position on the aircraft to an array of spaced apart acoustic sensors proximate the location. The method includes at least one of (i) determining a time difference of arrival of the acoustic signal between each of the acoustic sensors and a reference acoustic sensor and (ii) determining an arrival time of the acoustic signal at each of the spaced apart acoustic sensors. The position of the aircraft is determined from the time differences of arrival and/or the arrival times.