Abstract
THE Department of Scientific and Industrial Research has recently issued a report by Sir Edward Appleton and Dr. W. J. G. Beynon entitled "Radio Research special Report No. 18 : The Application Lonospheric Data to Radio Communication" (London : H.M. Stationery Office, 1948; Is. net). This publication comprises a reprint in a single booklet of two papers published by the authors in the Proceedings of the Physical Society in 1940 and 1947 together with material taken from confidential reports circulated during the War and now published for the first time. A large portion of the report is of a theoretical nature, and shows how radio waves which strike at various angles the reflecting layers of the upper atmosphere, situated at heights of 100-400 km., are bent so as to arrive back at the earth's surface at distances which may be hundreds or even thousands of kilometres from the sending station. The results of such calculations are presented in a number of graphs, which indicate to the radio engineer the best wave-length or frequency to use when he desires to transmit a message or programme to a given distance in a particular direction. By sending up radio waves vertically into these reflecting layers, or the ionosphere as it is termed, and by studying the reflexions on their return to earth, one can deduce the properties of these layers and the manner in which they change from day to night, season to season and year to year. Thus by making local measurements in different parts of the world, the practical radio engineer can assess the effectiveness of his sending stations and the range at which adequate signals will be received at various times or seasons. The later sections of the report refer briefly to some experiments, to be described in more detail elsewhere, which have been successfully made to check the accuracy of the theoretical analysis. The work described in the report fdrms the basis for the design and operation of many of the radio-communication and broadcasting services in use to-day.
Article PDF
Rights and permissions
About this article
Cite this article
Radio Communication and the Upper Atmosphere. Nature 163, 521–522 (1949). https://doi.org/10.1038/163521d0
Issue Date:
DOI: https://doi.org/10.1038/163521d0