Observations of Fine Structure in Hf Radio Signals Propagated Around the World

摘要

A fine structure has been observed in oblique ionograms taken over round-the-world paths. This structure appears as roughly horizontal striations on the time-delay vs frequency plots of the received signals, and several examples of these ionograms, taken during the course of a year, are shown. The form of the structure varies with the time of day; however, a degree of overall constancy can be found in records taken six months apart. It is thought that the fine structure represents a resolution of the paths taken by the RTW signal. (Author)