HF groundwave radar equations

HF radar groups working within separate organisations are likely to use different versions of the HF radar equation. When it is necessary to collaborate, or otherwise share know-how, there are fresh opportunities for misunderstanding. In this paper some alternative definitions of transmission loss, antenna gain and target backscattering cross-section are introduced and discussed. A number of HF groundwave radar equations with self consistent parameter definitions are presented. One particular equation is recommended. Using the parameter definitions presented here, it is relatively straightforward to derive skywave radar equations, although the algebra is less compact