A study of short, period sky-wave fading of CW emissions shows that observed characteristics are functions of the relative amplitude of the received

and

magnetoionic components. When the received magnetoionic components are essentially equal at the receiving point, severe and rapid fading occurs and variations in short-period fading are maximum. However, when a single mode of propagation is suppressed, the variations in short-period fading distributions of the received field are reduced and become lognormal in character. A new parameter is suggested to replace the Rayleigh distribution in cases where a more accurate formulation of short-period fading characteristics is desired. Finally, a description is given of apractical method of emitting CW radio transmissions, which yields reflections from the ionosphere of a single ionospheric mode, thereby obtaining some man-made control over short-period sky-wave fading.