Real-Time Update of Two H.F. (High Frequency) Channel Evaluation Models by Oblique Sounding
NAVAL RESEARCH LAB WASHINGTON DC
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The Naval Research Laboratory NRL has been examining techniques by which the HF propagation channel may be more accurately characterized by providing a real-time update capability to existing models of the channel. Several update sources are envisioned including data from vertical incidence sounders, topside sounders, and oblique sounders. This paper discusses new results obtained by updating two currently available models with oblique sounder data. The oblique sounders used are associated with the BR Communications, Inc. ANTRQ-35 tactical frequency management system TFMS currently in use by the Department of Defense. The approach is to obtain maximum observed frequency MOF information from an oblique sounder for a specific reference path. This information is used to obtain an update by forcing the model to fit the measurement over the reference path. As a measure of effectiveness, the updated model is then used to compute MOFs for experimental paths where MOF data are available coincident in time. In tactical scenarios, these would be unknown paths over which information is desired. Initial work indicates that providing a real-time update to a model from an oblique sounder may significantly improve the performance of the model over the reference as well as the experimental unknown paths.
- Radiofrequency Wave Propagation
- Radio Communications