Use of ionospheric models in HF radio planning and OHD target location

摘要

Propagation predictions are needed for the planning of communications and broadcasting circuits and services. Information is often required many years in advance. The author looks at the model requirements and the timescale for ionospheric measurements on which the model will be based. He looks at prediction problems, retrospective studies and the particular needs of over-the-horizon (OHD) sensor users.