S. V. Kozlov

A complicated structure of propagation medium as well as continuous changes in ionospheric plasma parameters exert great influence on both HF-waves propagation and insertion of errors in the direction or position finding. As it is known, under the condition of multi-mode propagation of signal, real mean-square estimation of these errors can be obtained experimentally only. In connection with that, boah a methodic of controllable experiment allowing of obtaining necessary data as single- and multimode signal array it the receiving point, and design schemes of hard and software components of a multichannel HF single-position direction finding post are examined. Furthermore, there were represented both the results of experimental determination of angular parameters of a received signal (azimuth and tilt angle), and the distance calculated on application of HF single-position direction finding, provided with vertical and horizontas ionospheric sounding data used for correction of a basic ionospheric model. During the analysis of experimental data for both single- and multimode signal propagation, there were revealed a number of factors, having influence on values of inserted errors, what enables to minimize them