A computer-implemented method of geolocating a target includes: receiving, from a plurality of sources, a corresponding plurality of angle estimates of the target relative to the respective sources; generating a corresponding plurality of planar renditions of the received angle estimates; selecting a combination of two or more planar renditions whose intersection defines a polygon; in response to multiple such combinations, selecting one having a largest number of planar renditions; and determining a center of the polygon of the selected combination. A computer-implemented method of evaluating geolocation geometry with respect to a target includes: geolocating the target from received sensor data of the target from multiple sources and location data of the sources; generating entries of a covariance matrix from the location data and the geolocation; deriving eigenvalues of the covariance matrix from the generated entries; and comparing the derived eigenvalues to evaluate the geolocation geometry with respect to the target.

A computer-implemented method of geolocating a target includes: receiving, from a plurality of sources, a corresponding plurality of angle estimates of the target relative to the respective sources; generating a corresponding plurality of planar renditions of the received angle estimates; selecting a combination of two or more planar renditions whose intersection defines a polygon; in response to multiple such combinations, selecting one having a largest number of planar renditions; and determining a center of the polygon of the selected combination. A computer-implemented method of evaluating geolocation geometry with respect to a target includes: geolocating the target from received sensor data of the target from multiple sources and location data of the sources; generating entries of a covariance matrix from the location data and the geolocation; deriving eigenvalues of the covariance matrix from the generated entries; and comparing the derived eigenvalues to evaluate the geolocation geometry with respect to the target.

A method of detecting an unknown signal and estimating a source location of the unknown signal using aircraft based on an automatic dependent surveillance-broadcast (ADS-B) system is provided. The method includes a first step (S100) for obtaining from a plurality of airborne aircrafts provided with a network system, an aircraft signal transmitted to neighboring aircraft. The method further includes a second step (S200) for detecting, by one of the plurality of aircraft, a presence of the unknown signal in the aircraft signal based on one of a time difference of arrival (TDOA) method, a time of arrival (TOA) method, and an angle of arrival (AOA) method. The method further includes a third step (S300) for estimating the source location of the unknown signal and a fourth step (S400) for transmitting unknown signal generation information and the source to neighboring aircraft and the ATC through a flight information services-broadcast (FIS-B).

A method of detecting an unknown signal and estimating a source location of the unknown signal using aircraft based on an automatic dependent surveillance-broadcast (ADS-B) system is provided. The method includes a first step (S100) for obtaining from a plurality of airborne aircrafts provided with a network system, an aircraft signal transmitted to neighboring aircraft. The method further includes a second step (S200) for detecting, by one of the plurality of aircraft, a presence of the unknown signal in the aircraft signal based on one of a time difference of arrival (TDOA) method, a time of arrival (TOA) method, and an angle of arrival (AOA) method. The method further includes a third step (S300) for estimating the source location of the unknown signal and a fourth step (S400) for transmitting unknown signal generation information and the source to neighboring aircraft and the ATC through a flight information services-broadcast (FIS-B).

An apparatus for indicating a direction of a radio transmission is described. The apparatus includes at least one vector detection device including two or more antennas and an attenuating material between at least one of the antennas and a source of a radio transmission. The attenuating material is arranged to vary an amount of attenuation with an angle of the source with respect to at least one of the antennas. The apparatus is configured to generate a signal indicating a direction of the radio transmission by comparing received signal strengths from the two or more antennas.

An apparatus for indicating a direction of a radio transmission is described. The apparatus includes at least one vector detection device including two or more antennas and an attenuating material between at least one of the antennas and a source of a radio transmission. The attenuating material is arranged to vary an amount of attenuation with an angle of the source with respect to at least one of the antennas. The apparatus is configured to generate a signal indicating a direction of the radio transmission by comparing received signal strengths from the two or more antennas.

A positioning system, method and computer program product determine a position of a mobile device, such as in instances in which the mobile device is indoors. In regards to a positioning system, the positioning system is caused to determine a signal strength of signals received from at least first and second directive antennas of a beacon and at least a non-directive antenna of the beacon. The positioning system is also caused to normalize the signal strength of the signals received from the first and second directive antennas based on the signal strength of the signals received from the non-directive antenna in order to determine normalized signal strengths of the signals received from the first and second directive antennas. The positioning system is further caused to determine an angle at which the signals from the beacon propagate based upon the normalized signals strengths.

Described examples include light fixtures and/or radio frequency (RF) nodes located in a service volume provided with a mobile asset detection system. The RF nodes receive beacon signals transmitted by mobile assets within the service volume. The mobile asset detection system includes a processor, a transceiver and multi-element antenna array. The multi-element antenna array includes multiple discrete antenna elements that, in some examples, are arranged so that at least one of the discrete antenna elements is non-coplanar with the other discrete antenna elements of the antenna array. Using signal attribute values determined from a signal received via each of the respective discrete antenna elements, a three dimensional estimate of the location of the mobile assets in a service volume may be determined.

Described examples include light fixtures and/or radio frequency (RF) nodes located in a service volume provided with a mobile asset detection system. The RF nodes receive beacon signals transmitted by mobile assets within the service volume. The mobile asset detection system includes a processor, a transceiver and multi-element antenna array. The multi-element antenna array includes multiple discrete antenna elements that, in some examples, are arranged so that at least one of the discrete antenna elements is non-coplanar with the other discrete antenna elements of the antenna array. Using signal attribute values determined from a signal received via each of the respective discrete antenna elements, a three dimensional estimate of the location of the mobile assets in a service volume may be determined.

Disclosed, among other things is a wide area direction finding system comprising multiple radio frequency (RF) receiving units and a display computer. The RF receiving units may be in different geographic areas to make use of triangulation to precisely locate a target, allowing for increased area coverage and accuracy when locating a target. Locating a target may draw from real-time information using a live mode, or from a past event using a history mode on the display computer.