A note on wireless signal strength measurements made during the Solar Eclipse of 24 January, 1925

Abstract

In the course of a series of signal intensity measurements made at Cambridge on the electric waves received from broadcasting stations a marked difference between day and night conditions has been observed. The day-time signals are sensibly constant but marked fluctuations of intensity become apparent about sunset and continue throughout the night. These variations are detectable at Cambridge on the signals from London, where they represent a change in strength of about 5 per cent.

Incoherent scatter of radio waves from the ionosphere

“…Systematic radio studies of the upper atmosphere from the ground started over fifty years ago with the pioneer experiments of Appleton and Barnett (1925). The principle of their experiment was closely analogous to that of Lloyd's mirror interference experiment in optics.…”