Short-term forecasting for a high-frequency long-distance point-to-point communication path

Three techniques are presented which can allow the communicator to make maximum usable frequency forecasts. First, one-half hour, one hour, and two hour forecasts are made using running five-day median MOF curves obtained from data acquired by a synchronized step frequency sounder system. Fifty percent of the half-hour forecasts had an error no greater than 0.4 MHz. Second, short-term forecasts are also made using predicted information. Third, an independent forecasting method using selected frequency sampling of the failure time and recovery time of assigned frequencies is presented. As an example, forecasts for a 7800 km midlatitude HF propagation path are presented.