Investigations of Kennelly-Heaviside Layer Heights for Frequencies between 1600 and 8650 Kilocycles per Second

The results of observations of the height of the Kennelly-Heaviside layer carried out near Washington, D.C., during 1930 are presented. Evidence for the existence of two layers (corresponding closely in virtual height to the E and F regions discussed by Appleton) is found during daylight on frequencies between three and five megacycles. The modification in the virtual height of the higher F layer produced by the existence of a low E layer is investigated theoretically, and the possibility of large changes in virtual height near the highest frequency returned by the E layer is pointed out. A number of oscillograms showing the characteristic types of records observed during the tests are presented together with a graph of average heights from January to October, 1930.