HF Propagation modeling validation for Earth to space transmission by multiple bounces links

The HFPE (HF Propagation Experimentation) technological experiment aims at consolidating a new concept of long-range transmissions between ground and the Low Earth Orbit (LEO). This concept relies on over-the-horizon trans-ionospheric links in the HF-band. To prepare this experiment, propagation modelling has been carried out and more particularly, a HF link planning software called MSATIS [1] [2]. Since this development, new constraints appeared in the demonstration: in accordance with the frequency regulation, only several fixed frequencies can be used in the HF spectrum. Second, the demonstration needs also accurate time synchronization, and propagation delay must be predicted. In order to reach these two new constraints, a new Earth - Space HF propagation model, based on ray-tracing principle, has been developed, and is presented in this paper.