Surface impedance of the "thin ice-sea" structure

For calculations of the electromagnetic field of the two-layer "thin ice-sea" structure, the areas of applicability of the impedance boundary conditions are determined depending on the thickness of the ice and the angle of incidence of the vertically polarized wave. Results are needed to calculate the attenuation function W and the radio wave field level. It is shown that for the "thin ice-sea" structure, taking into account the dependence of surface impedance on the angle of incidence is important for over-the-horizon radar systems in the HF range of radio waves. In the VHF range for ice 80 cm thick, frequency bands are identified in which impedance boundary conditions are applicable.