Rigorous Prediction of the Ground Wave Above Flat and Rough Highly-Conducting One-Dimensional Sea Surfaces in HF-VHF Band

For horizontally and vertically polarized line sources in HF-VHF band, a detailed analysis of the propagation over one-dimensional highly-conducting smooth and rough sea surfaces is addressed from an efficient rigorous numerical method: the method of moments combined with the BMIA-CAG approach and with the impedance boundary condition (Leontovitch approximation). This method can treat a huge problem, typically, ranging from 200 000 to 300 000 for the number of unknowns on the surface, which allows us to show, for the TM polarization, the ground wave propagation over a long distance. The contribution of the surface wave is then exhibited for a smooth sea surface and compared with the Collin asymptotic formulation deduced from the Sommerfeld integral. The surface roughness effect on the propagation is also investigated.