Features of Radiopulse Propagation in Media with Dispersion

Mathematical numerical modeling of amplitude structures of the radiopulses propagating in homogeneous ionospheric plasma is fulfilled. Changes of radiopulse thin structures depending on plasma frequency, distance up to a source of radiation and width of a signal had been investigate by the methods of the space - time geometrical theory of diffraction. Numerical comparison non-uniform and uniform asymptotics, containing Fresnel and Bessel functions is executed. Is established, that the sizes of a vicinity of a light cone, where the application of a uniform asymptotic as Bessel function is necessary are rather insignificant. Inapplicability of parabolic approximation for study of thin radiopulses structures is shown.