To automatically determine geographic positions of signal sources in areas with limited satellite coverage, a system receives signal data collected by a receiver moving along a path through a geographic area with limited satellite coverage, the signal data being indicative of changes, over a period of time, in strength of respective signals detected by the moving receiver and emitted by multiple signal sources statically disposed along the path. The system determines a time it takes for a length of a vehicle to pass by the signal source at the determined speed. The system then calculates static positions of the signal sources using the signal data and the determined time, including associating the location of each signal source with a time when the signal source was directly over the roof of the vehicle in which the moving receiver is travelling.

First information corresponding to a radio signal received at a first sensing device from a candidate location is obtained. Second information corresponding to a radio signal received at a second sensing device from the candidate location is obtained. A first relationship between the first sensing device and the candidate location and a second relationship between the second sensing device and the candidate location are determined. A first inverse and a second inverse of respectively the first and second relationships are obtained. A first estimate of the radio signal at the first sensing device is determined from the first information and the first inverse. A second estimate of the radio signal at the second sensing device is determined from the second information and the second inverse. Energy emitted from the candidate location is measured based on the first estimate and the second estimate.

A system for determining a bearing or location of a radio frequency identification (RFID) tag using a handheld RFID reader is described. In one embodiment, the reader is equipped with an accelerometer. A user moves the reader while the reader receives the tag's signal and determines the tag signal's phase at multiple locations. The locations of the reader antenna can be reconstructed using the accelerometer data. By using the phase determined at multiple locations in conjunction with the location of the reader antenna, the reader can determine the bearing of the tag. For an RFID reader not equipped with an accelerometer, the sign and ratio of the rate of change in the phase of a tag's signal to the distance traveled by the reader antenna can be used to determine the location of the tag relative to the reader.

The technology enables locating asset tracking tags based on a ramped sequence of signals from one or more beacon tracking tags. The sequence includes at least one minimum power signal and at least one maximum power signal. Each signal in the sequence has a tag identifier and an initial signal strength value. Each beacon signal in the ramped sequence is associated with the time at which that beacon signal was received by a reader. Each beacon signal is also associated with a received signal strength at reception. A location of the beacon tracking tag is estimated according to the signals in the sequence based on the difference between the initial and received signal strengths. A position of the reader device is identified based on the beacon tag's location. An asset tracking tag location is identified based on the reader's location and packets received by the reader from the asset tag.

A method and device determines an evolving position of a device using electromagnetic interference, which is jamming electromagnetic navigation signals. An antenna arrangement receives both the electromagnetic navigation signals and the electromagnetic interference. A discerned position is determined for each of one or more jamming antennas emitting the electromagnetic interference. A detection circuit determines each discerned position from the electromagnetic interference received at the device and at least one measurement of the evolving position using the electromagnetic navigation signals. The evolving position of the device is determined while the electromagnetic interference prevents subsequently measuring the evolving position using the electromagnetic navigation signals. An evaluation circuit determines the evolving position from the electromagnetic interference received at the device and from each discerned position of the one or more jamming antennas.

Method, mobile device, computer program product, and apparatus for optimizing sensor reporting are described. A mobile device can measure radio frequency (RF) signal characteristics while receiving data from one or more mobile device sensors. The mobile device may determine its relative displacement between RF signal measurements. The mobile device can send a representation of the RF signal characteristics and the displacement data to one or more servers. The representation displacement data may include one or more reliability characteristics and/or a displacement reliability rating. A server can obtain the displacement data and RF signal characteristics to determine positioning of wireless transmitters in an environment and build a positioning database.

Venue information is stored, the venue information including a first location portion of the venue and a second location portion of the venue. An actual presence of a location sensing mobile device is identified within the venue, the actual presence identified based on beacon signals received from a beacon associated with the first location portion of the venue. A first drone associated with the first location portion of the venue is selected based on the actual presence. First sensor data is received from the first drone. A virtual presence of the location sensing mobile device is received, the virtual presence being different from the actual presence. A second drone associated with the second location portion of the venue is selected based on the virtual presence. Second sensor data is received from the second drone. The first and second sensor data is transmitted to the location sensing mobile device.

A method includes: determining a reference direction for orientation; when a first device rotates around an obstruction, receiving a wireless signal sent by a second device, and obtaining a link quality parameter value according to the received wireless signal; determining a position having greatest shadow fading of the first device according to the obtained link quality parameter value, and using a pointing direction of the position having greatest shadow fading of the first device as a first pointing direction; and determining, according to an included angle θ.sub.1 between the reference direction and the first pointing direction and an included angle θ.sub.2 between the reference direction and a second pointing direction, a direction in which the second device is located, where the second pointing direction is a pointing direction of the first device.

Systems, methods, and apparatus for identifying and tracking UAVs including a plurality of sensors operatively connected over a network to a configuration of software and/or hardware. Generally, the plurality of sensors monitors a particular environment and transmits the sensor data to the configuration of software and/or hardware. The data from each individual sensor can be directed towards a process configured to best determine if a UAV is present or approaching the monitored environment. The system generally allows for a detected UAV to be tracked, which may allow for the system or a user of the system to predict how the UAV will continue to behave over time. The sensor information as well as the results generated from the systems and methods may be stored in one or more databases in order to improve the continued identifying and tracking of UAVs.

A target device positioning method and a mobile terminal are provided. The mobile terminal determines, according to obtained measurement signals sent by a target device from a trigger moment to a current measurement moment, azimuths of the target device relative to the mobile terminal at the moments, obtains an original motion trail of the target device from the trigger moment to the current measurement moment, determines an effective motion trail of the target device according to the original motion trail and change rates of the azimuths of the target device relative to the mobile terminal at the moments, performs matching with a map according to an azimuth of the target device relative to the mobile terminal at the current measurement moment and the effective motion trail of the target device, to determine location information of the target device, and displays the location information of the target device.