A propagation monitoring system for HF broadcast prediction enhancement

This paper describes an autonomous HF field-strength monitoring terminal which has embedded automatic synchronisation capabilities. This monitoring system is proposed for use in the forthcoming International Telecommunications Union´s (ITU) global HF field-strength monitoring campaign. The receiving terminal has been designed with low cost in mind, and utilises digital signal processing techniques to allow amateur grade RF equipment to be used. The terminal automatically detects probe signals from up to 5 individual transmitters and records a calibrated estimate of the field-strength received from each transmitter for later retrieval and analysis. The ITU hopes to utilise a number of these receiving terminals distributed throughout the globe, together with centralised data collection and analysis, to increase understanding of HF propagation conditions on a global basis