Lunar Radio Echoes and the Faraday Effect in the Ionosphere

Abstract

SUCCESSFUL observations of the reflexion of radio waves from the moon have been made by workers in the United States and Australia. Both DeWitt and Stodola¹ and Kerr and Shain² found that the lunar echoes showed rapid fading (periods of seconds), for which the most likely cause appeared to be the libration of the moon. They also noted a different type of fading of much longer period for which no satisfactory explanation has been found, although Kerr and Shain obtained evidence that it might have an ionospheric origin. A radio echo equipment at the Jodrell Bank Experimental Station has recently been used in an investigation of the fading of lunar echoes; the results are in general agreement with this previous work as regards the origin of the short-period fading. The purpose of the present communication is to offer an interpretation of the long-period fading.