Analytic Propagation Approximation over Variable Terrain and Comparison to Data

An analytical modeling methodology to rapidly predict signal strength over variable terrain has been developed. Methodology relies on approximating the intervening terrain by a constrained parabola, allowing the use of a modal sum solution. The model has been compared against an extensive data set of over 3000 links, measured in a desert environment of Fuerteventura, Spain, resulting in 8.5 dB RMS error, an improvement over a linear fit to data, which has 12.5 dB RMS deviation. The model is intended for use in future lunar missions where rapid coverage calculations are important for selection of optimal landing sites.