Abstract
The observed intensity at the surface of the earth of radiation at a frequency of 50 Mc./s. from a radio star has been studied. A relationship is shown to exist between the fluctuations, or scintillations, in this observed radiation intensity and the angle of its incidence on the 400 km. level of the earth's ionosphere. The occurrence of these scintillations is compared with other ionospheric phenomena as determined by vertical soundings from the earth. The probable cause of the fluctuations has been localized to a source in the high ionospheric regions.