High Frequency Geolocation (HFGeo)

High Frequency (HF) communications systems and radars are in widespread use around the world. Accurate standoff geolocation and characterization of these sources are difficult because of ionospheric variations, the high noise environment that exists at these frequencies, and ionospheric polarization rotation, multipath-induced signal fading, and simultaneous multiple angles-of-arrival.

Recent advances in high dynamic range receivers, antenna techniques, adaptive signal processing, and ionospheric ray path prediction, along with improved measurement and modeling techniques suggest that a dramatic improvement in HF reception and geolocation is possible.

The HFGeo Program aims to develop and prototype technology that will provide a dramatic improvement in the ability to geolocate and characterize HF emitters. Desired technical innovations include 1) the ability to accurately resolve multiple angles-of-arrival and polarization states through novel antenna concepts; 2) the ability to enhance signal-to-noise ratio (SNR), signal detection and source geolocation with multi-dimensional adaptive signal processing; and 3) the ability to accurately determine the state of the ionosphere. In later phases of the program, these technology innovations will be further developed and integrated into geolocation and source characterization applications.

Related Program(s)