An apparatus having processing circuitry configured to estimate beyond line-of-sight emitter location may be configured to receive signal information indicative of TDOA and FDOA measurements at a first receiver and a second receiver. The signal information may be generated based on indirect wave signals received from the emitter at each of the first and second receivers. The processing circuitry may be further configured to employ a first analytical model of the ionosphere to generate coarse TDOA and FDOA contour maps, and generate a first geolocation estimate based on the coarse TDOA and FDOA contour maps.

Methods, apparatus, systems and articles of manufacture are disclosed to validate data communicated by a vehicle. An example apparatus an anomaly detector to, in response to data communicated by a vehicle, at least one of compare an estimated speed with a reported speed or compare a location of the vehicle with a reported location. The apparatus including the anomaly detector further to generate an indication of the vehicle in response to the comparison. The apparatus further includes a notifier to discard data sent by the vehicle and notify surrounding vehicles of the data communicated by the vehicle.

A method includes obtaining signal information corresponding to a plurality of radio signals received at two or more sensing devices from a candidate location, determining a plurality of reconstructed signals based on the signal information, determining time-estimates and frequency-estimates based on a correlation between the plurality of radio signals and the plurality of reconstructed signals, determining metadata corresponding to the plurality of radio signals based on the signal information, the time-estimates, or the frequency-estimates, transmitting at least a portion of the metadata to an information combining node, obtaining the portion of the metadata from the information combining node, determining a relationship between the metadata, and determining the candidate location based on the metadata and the relationship between the metadata. Transmission of the plurality of radio signals to the information combining node is restricted based on a bandwidth of the two or more sensing devices or the information combining node.

Methods, systems and computer program products for radionavigation for swimmers are described. A mobile device configured to estimate a location using radio frequency signals can estimate a position of the swimmer when the mobile device is worn on a limb of the swimmer and periodically submerged. The mobile device can supply auxiliary information to a radionavigation subsystem to correct a navigation solution affected by limb motion of the swimmer and affected by the periodic submersion of the mobile device.

Systems, methods, and apparatus for location determination of an emitter using frequency-of-arrival (FOA) measured from a single moving platform are disclosed. In one or more embodiments, a disclosed system allows for location determination of stationary, pulsed radio frequency (RF) emitters from a moving platform by using coherent frequency of arrival (CFOA) Doppler history measurements. The term coherent is used to indicate that the process requires a RF-coherent pulse train, such as that generated by modern radar. In one or more embodiments, the disclosed system employs one of two disclosed CFOA measurement methods (Method 1: CFOA linear regression of phase (LRP), and Method 2: CFOA cross-correlated frequency spectra (CCFS)). The disclosed system also enables geo-discrimination (GeoD) of emitters at known locations, or alternatively geo-location of emitters at unknown locations.

Systems, methods, and apparatus are provided for automated identification of open space in a wireless communications spectrum, by identifying sources of signal emission in the spectrum by automatically detecting signals, analyzing signals, comparing signal data to historical and reference data, creating corresponding signal profiles, and determining information about the open space based upon the measured and analyzed data in near real-time.

A method of geolocating comprises: receiving wirelessly, at an asset located on the Earth's surface and from at least two airborne aircraft, ADS-B signals, respectively; interpolating, using a Bayes filter, at least some state information of the at least two airborne aircraft based on the ADS-B signals, respectively; determining differences in received signal strength indicator (RSSI) values (RSSI-difference values) of successive aircraft-specific ADS-B signals, respectively; estimating, using a likelihood function, locations of the asset based on the RSSI-difference values, the ADS-B signals and the interpolated state information, respectively, thereby producing a set of estimated locations; and searching amongst the set to find one of the estimated locations that is regarded as being most likely to most accurately describe an actual position of the asset.

The present disclosure relates to localization methods, apparatuses, and systems. One example localization method includes obtaining phase value groups respectively corresponding to a plurality of anchor nodes, where phase values corresponding to the plurality of anchor nodes are obtained through measurement after the plurality of anchor nodes perform frequency shifting and receive a signal sent by a target node while performing frequency shifting, and the phase value group includes phase values of a plurality of frequencies, and determining a location of the target node based on the phase value groups respectively corresponding to the plurality of anchor nodes.

The present invention relates to an apparatus for estimating the location of a receiver and a method of estimating the location of a receiver. A location estimation apparatus according to one embodiment includes a receiving device for receiving information about a plurality of beams radiated from a transmitter at different radiation angles; a radiation pattern reader for reading radiation pattern information corresponding to each of the beams based on information about the beams; and a location estimator for comparing the read radiation pattern information with each other and estimating the location of a receiver based on the comparison result.

In a positioning system, a plurality of transmitter units (2, 3, 4, 5) transmit respective transmitter-specific identification signals at intervals, which are received at a mobile receiver unit (7). A processing system (7; 9) identifies the transmitter unit that transmitted each received identification signal, and, for each signal, determines range data from time of arrival data and determines distance data from Doppler shift information. The range data and distance data are compared to determine range error data. A position estimate for the mobile receiver unit (7) is determined by solving an optimisation problem using range estimates determined for the plurality of transmitter units, weighted in dependence on the range error data.