The invention relates to a method (for determining calibration data for an airborne goniometry apparatus comprising an antenna array of several antennas, from several sets of calibration data measured in-flight by said goniometry apparatus, each associated with a measured angular position and comprising an amplitude datum and a phase datum measured by each antenna in said antenna array at said measured position.

The method comprises, for an estimated angular position, a phase (200) of calculating an estimated calibration data set and comprising the following steps: for each measured position, normalizing (204) the data set measured at said measured position, with respect to the phase data measured by each antenna, said normalizing providing as many normalized data sets as there are antennas for each measured position; for each antenna, calculating (206) a candidate data set by interpolating the measured data sets at said measured positions and previously normalized with respect to the phase measured by said antenna; selecting (210), as the estimated calibration data set, the candidate data set whose phase reference has the highest energy among said candidate data sets.

It also concerns a computer program and an apparatus implementing such a method, a calibration table obtained by such a method and a goniometry apparatus calibrated with such a method.

A radio-frequency method for range finding includes modulating a reference signal having an intermediate frequency to a downlink signal having a carrier frequency using a clock signal. The downlink signal is transmitted to a tag using a transceiver. An uplink signal backscattered from the tag is received and demodulated using the clock signal. The uplink signal has a frequency that is a harmonic of the carrier frequency. A distance between the tag and the transceiver is calculated based on a phase of the demodulated uplink signal. A system for range finding includes a transceiver and a processor. The transceiver modulates a reference signal to a downlink signal and transmits the downlink signal. The transceiver receives and demodulates an uplink signal. The processor is configured to receive the demodulated uplink signal and calculate a distance between the tag and the transceiver using a phase of the demodulated uplink signal.

An object monitoring system including a plurality of location beacons, each location beacon being configured to generate a location broadcast message indicative of a beacon location and a tag associated with a respective object in use. The includes a tag memory configured to store object rules, a tag transceiver configured to transmit or receive messages and a tag processing device configured to determine context data at least partially indicative of a tag context by at least one of determining a tag location in accordance with at least one location broadcast message received via the tag transceiver from at least one of a plurality of location beacons and using stored context data, use the object rules and the context data to identify a trigger event, determine an action associated with the trigger event and cause the action to be performed.

A method comprises a first device: receiving at least one Bluetooth Low Energy message transmitted from each of at least three second devices, each Bluetooth Low Energy message including data indicating a position of the respective second device (S2); measuring a radio parameter for each of the received Bluetooth Low Energy messages (S3); using the radio parameters and the data included in the messages to calculate the position of the first device (S4); and transmitting a Bluetooth Low Energy message including data indicating the position of the first device (S5). A further method comprises a third device: receiving at least one Bluetooth Low Energy message transmitted from each of at least three devices, each Bluetooth Low Energy message including data indicating a position of the respective device; measuring a radio parameter for each of the received Bluetooth Low Energy messages; using the radio parameters and the data included in the messages to calculate the position of the third device; receiving at least one Bluetooth Low Energy message transmitted by a first device and including data indicating a position of the first device; and causing display of the position of the first device relative to the third device.

The present invention relates to a communication assembly comprising a first terminal provided with a first communication module arranged to communicate with a plurality of beacons, each comprising a communication circuit to enable data to be sent and/or received with a particular periodicity Said assembly additionally comprises a second terminal having a second communication module, wherein said second terminal is arranged to scan its environment by means of said second communication module in order to detect the presence of beacons within range and to retrieve for each beacon detected the particular periodicity and a time offset corresponding to the period between a reference point and the start of the transmission of the message and send them to the first terminal.

Disclosed embodiments relate, generally, to beacon systems where a locator beacon is used as a marker for a location of interest, and improving false positive immunity in such beacon systems. Confiner beacons are included in such beacon systems to confine a triggering area for triggering a location indication for a location of interest marked by a locator beacon. In other embodiments, arbitrarily shaped triggering areas are defined using confiner beacons. In other embodiments, errant locator signals are identified and handled (e.g., ignored).

Disclosed herein are embodiments of a balloon-based positioning system and method. In one example embodiment, a system includes a group of at least three balloons deployed in the stratosphere and a control system configured for: determining a first set of spatial relationships relating to the group; determining a second set of spatial relationships relating to at least a portion of the group and to a reference point; determining a position of the reference point relative to the earth; using the determined first set, the determined second set, and the determined position of the reference point relative to the earth as a basis for determining a position of a target balloon in the group relative to the earth; and transmitting the determined position of the target balloon relative to the earth.

A portable corrosion monitoring device is described that includes at least one corrosion monitoring sensor, a wireless transceiver configured to receive signals from a plurality of remote wireless beacons, a microprocessor containing executable instructions to determine the spatial position of the portable corrosion monitoring device based, at least in part, on the signals received from the plurality of remote wireless beacons, and a visual display to communicate instructions to an operator of the portable corrosion monitoring device.

Techniques are generally described for determining locations of a plurality of communication devices in a network. In some examples, methods for creating a location discovery infrastructure (LDI) for estimating locations of one or more of a plurality of communication nodes may comprise one or more of determining a plurality of locations in the terrain to place a corresponding plurality of beacon nodes, determining a plurality of beacon node groups for the placed beacon nodes, and determining a schedule for the placed beacon nodes to be active. Additional variants and embodiments are also disclosed.

In an aspect, a communications device obtains a residual AoA bias associated with a first AoA measurement of a RS-P transmitted from a wireless reference node to a first base station, the wireless reference node associated with a location known to the communications device, obtains a second AoA measurement associated with an uplink signal (e.g., PRACH, SRS, UL-SRS-P, etc.) transmitted from a UE to the first base station, and calibrates the second AoA measurement based on the residual AoA bias. In another aspect, a communications device obtains a residual AoD bias associated with a first AoD measurement of a RS-P transmitted from a first base station to a wireless reference node with a known location, obtains a second AoD measurement associated with a downlink signal (e.g., DL-PRS) transmitted from the first base station to a UE, and calibrates the second AoD measurement based on the residual AoD bias.