Asymptotic methods of calculating the propagation of centimeter radio waves in the atmosphere in space-space paths

Asymptotic methods of calculating the propagation of centimeter radio waves in a neutral atmosphere in space-space paths are considered. The methods are based on the technique of Fourier integral operators. The approximations that allow the representation of the corresponding operators as compositions of nonlinear coordinate changes, multiplications by reference signals, and Fourier transformations are constructed. The approximations are based on a technical procedure using a linearized canonical transform. This approach makes it possible to devise fast numerical algorithms. Numerical simulations are conducted with the use of realistic global gridded fields of meteorological parameters including the turbulence. The numerical simulations show high accuracy and efficiency of the proposed methods.