The Surface Impedance of the "Thin Ice - Sea" and "Thick Ice - Sea" Structures in VLF-VHF Radio Wave Bands

Abstract

To calculate the propagation of the electromagnetic field over the two-layer struc-ture "ice - sea", 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 in the range of 0.01-420 MHz. The article examines the structures "thin ice - sea" and "thick ice - sea" (six models of ice cover). The ice thickness varied from 0.03 to 9 m. The results are needed to calculate the atten-uation function and the field level in the VLF, LF, MF, HF, VHF radio wave bands. It is shown that for the structure “ice - sea” it is important to take into account the dependence of the surface impedance on the angle of incidence for over-the-horizon radar systems in the HF radio wave range. In the VHF range the frequency bands are determined for ice 80 cm thick, in which the impedance boundary condi-tions are applicable.