%0 Journal Article %A Pushin, V. F. %A Kostrov, L. S. %D 1999 %I Begell House %N 2 %P 58-64 %R 10.1615/TelecomRadEng.v53.i2.110 %T 3-D Ray-Tracing Synthesis of Multiparameter Ionograms as Obtained by Digital Sounders in a Disturbed Ionosphere %U https://www.dl.begellhouse.com/journals/0632a9d54950b268,7d8ddafe6740a596,6be086372690f4bb.html %V 53 %X A ray-tracing technique is suggested for synthesizing multiparameter ionograms obtained with digital sounders under disturbed ionospheric conditions. The ionosphere is assumed to be a 3-D inhomogeneous quasi-stationary medium placed in an external magnetic field. The dual-point boundary-value problem for the ray equations is solved by the method of ballistics. The steepest descent method is applied within the approach to solve the set of nonlinear equations. To that end, the ray equations are complemented by equations for their partial derivatives with respect to parameters of the boundary-value problem. The radio wave parameters are given by curvilinear integrals of known functions, taken along the ray connecting two specified points. The extended set is solved numerically. Analytic solutions have been obtained for simplified dispersion relations in the vicinity of reflection points for the O- and X-modes. The numerical and analytic solutions are matched at the edge of the reflecting region. Data bank perturbation models are used for the ionogram synthesis. The regular background model of the ionosphere is corrected through Doppler shift measurements of the VHF signals from satellite radio beacons. The Dopplionograms characteristic of the perturbations like traveling ionospheric disturbances (TIDs) have been obtained. The results are compared with the measurements. %8 1999-02-01