HF Source Geolocation Using an Operational TDoA Receiver Network: Experimental Results

Determining the geographic location of high frequency (HF) transmitters is of prime importance in both defense and civil operations. In this letter, we present experimental results of distant HF transmitter geolocation performed using the time difference of arrival (TDoA) method. The HF signals considered for our study are transmitted from different locations across Europe. Multiple receivers capable of capturing HF radio signals synchronously are built, and a nationwide receiver network with centralized control is deployed in France to assess the feasibility of our approach. HF radio signals are captured simultaneously by all receivers in the network from different European HF broadcast transmitters. From the captured data, the propagation duration differences between the signals received by all receivers are obtained using the cross-channel sounding method. Finally, the transmitter location is estimated using the geolocation algorithm based on the TDoA method. Experimental results demonstrate that it is possible to locate the HF transmitters under favorable conditions with a relative geolocation error ranging from about 0.1 to 10% of the actual ground distance, for most of the experimental scenarios.