Numerical Maps of FoEs for Solar Cycle Minimum and Maximum

Margo Leftin · S. M. Ostrow · C. Preston

Jan 1968 · Institute for Telecommunication Sciences.

About this ebook

The preparation of world numerical maps of lower decile, median, and upper decile values of the monthly distributions of foEs for all 12 months of both a solar cycle minimum and a solar cycle maximum year is described. Tables of numerical maps of 4 representative months, March, June, September, and December, are given as examples of the complete set. Sample contour methods for these months are included to illustrate graphically the geographic, diurnal, seasonal, and solar cycle variation of lower decile, median, and upper decile foEs. No detailed instructions are given for using the maps, but a number of possible applications are indicated. The behavior of Es and problems of Es propagation are discussed, to indicate some limitations of the maps, and to call attention to additional data, such as Es reflections coefficients, needed to improve our knowledge of Es propagation and in particular to permit more accurate calculation of Es maximum usable frequency and transmission loss. The use of combinations of probabilities of both Es and regular layer propagation is recommended to provide improved estimates of actual propagation.