Concerning Optimum Frequencies for Space Vehicle Communication

In an earlier paper, on the same subject, a number of factors affecting communication with space vehicles were discussed. Among these were receiver signal-to-noise ratio as a function of temperature, cosmic noise, auroral displays, Faraday rotation of the plane of polarization, and gaseous refraction and absorption. The additional material in this paper treats in a semiquantitative manner and in greater detail the application of elevated heights for earth terminals of space communication systems. This expedient takes advantage of elevated heights to reduce the effects of water vapor and oxygen on limiting the spectrum for radio communication. It is possible to attain some isolation of circuits and extend the range of communication in selected portions of band of 10 to 60 kmc.