Calculation of the HF sky-wave field strength and maximum usable frequency using a programmable pocket calculator (HP97)

A calculation procedure is described. The propagation path can be selected to follow either the short or the long great circle and the propagation mode may be by F2- or E-layer reflection with up to ten skips. The field strength calculations comprise free-space attenuation, ionospheric absorption, ground-reflection losses and additional losses, as well as the gain of a curtain array antenna. The contribution covers the theoretical basis, instructions for the user, a comparison with other methods and the list of programs.