Abstract: A geolocation system (10) includes an emitter (12), a plurality of collection nodes (14,16,18), and a control station (20). Each collection node includes a receiver (24) that is operable to receive signals transmitted from the emitter (12), generate a reduced data stream that includes only signal data, and communicate the reduced data stream to the control station (20) along with navigation data. The receiver (24) identifies signal data by detecting an energy level of the raw collection data. More specifically, the receiver (24) determines a bandwidth and a signal-to-noise ratio of each portion of the collection data, and identifies each portion as including signal data if both the bandwidth and the signal-to-noise ratio exceed predetermined threshold amounts. The receiver (24) includes a digital signal processing component (36) for performing calculations used by the receiver (24) to determine the bandwidth and the signal-to-noise ratio.

Abstract: Systems and methods for detection and geolocation of multiple emitters that are emitting RF signal energy on a common frequency, and that may be implemented to separate, geolocate, and/or determine the number of emitters (e.g., radio users) emitting on a common RF frequency. Real-time signal qualification processing may be employed to continuously monitor and collect incoming receiver tuner data for signal activity and ignore irrelevant noise data. Each set of data blocks from an emitter transmission signal may be defined as an emission cluster, and a set of time difference of arrival (TDOA)/frequency difference of arrival (FDOA) pairs may be computed for each emission cluster with each TDOA/FDOA pair yielding a geolocation result. A statistical qualification method may be used to produce a final geolocation answer from each set of emission cluster geolocation results, and a geolocation error ellipse computed for the final geolocation answer of each emission cluster.

Abstract: Systems and methods for detection and geolocation of multiple emitters that are emitting RF signal energy on a common frequency, and that may be implemented to separate, geolocate, and/or determine the number of emitters (e.g., radio users) emitting on a common RF frequency. Real-time signal qualification processing may be employed to continuously monitor and collect incoming receiver tuner data for signal activity and ignore irrelevant noise data. Each set of data blocks from an emitter transmission signal may be defined as an emission cluster, and a set of time difference of arrival (TDOA)/frequency difference of arrival (FDOA) pairs may be computed for each emission cluster with each TDOA/FDOA pair yielding a geolocation result. A statistical qualification method may be used to produce a final geolocation answer from each set of emission cluster geolocation results, and a geolocation error ellipse computed for the final geolocation answer of each emission cluster.

Abstract: Methods and apparatus operable to estimate the geolocation of a signal emitter. In some embodiments, the methods comprise acquiring collection data from a plurality of collector elements, computing a plurality of candidate geolocations from the acquired collection data, and applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

Abstract: Methods and apparatus operable to estimate the geolocation of a signal emitter. In some embodiments, the methods comprise acquiring collection data from a plurality of collector elements, computing a plurality of candidate geolocations from the acquired collection data, and applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

Abstract: A geolocation system (10) includes an emitter (12), a plurality of collection nodes (14,16,18), and a control station (20). Each collection node includes a receiver (24) that is operable to receive signals transmitted from the emitter (12), generate a reduced data stream that includes only signal data, and communicate the reduced data stream to the control station (20) along with navigation data. The receiver (24) identifies signal data by detecting an energy level of the raw collection data. More specifically, the receiver (24) determines a bandwidth and a signal-to-noise ratio of each portion of the collection data, and identifies each portion as including signal data if both the bandwidth and the signal-to-noise ratio exceed predetermined threshold amounts. The receiver (24) includes a digital signal processing component (36) for performing calculations used by the receiver (24) to determine the bandwidth and the signal-to-noise ratio.