Antipodal HF radio propagation.

Abstract

In the 1950's and early 1960's a considerable amount of effort was devoted by Dr. H.A. Whale and others at the Seagrove Radio Research Station (now the Radio Research Centre, University of Auckland), to the examination of some of the problems involved in HF radio propagation. Among these were the evaluation of the effects of large-scale ionospheric tilts, the scattering which occurs at the earth and ionosphere, and the measurement and prediction of incoming bearing and elevation angles of signals from distant stations. In the latter stages of this work it became obvious that little was known about effects occurring at antipodal distances, so attempts were made to examine these and to postulate a propagation model consistent with the effects observed. The results presented in this thesis are a logical extension of this early work, and comprise investigations in three main areas: (1) The shape and size of the antipodal focussing area, (2) The development of a more general and less idealised propagation model, (3) The shape of the incoming angular power spectrum at antipodal distances. A summary of the theory and experimental results contained in chapters 4, 5, 6 and 7 has been published (Bold, 1969), and that contained in chapters 8 and 9 will be submitted for publication shortly.