Long-distance tropospheric propagation investigations in USSR last century

History and results of the far troposphere UHF wave propagation over terrestrial and marine paths carried out in the USSR during the second part of the XX century are given in the paper. The considerable part of the investigation was done by the group of the Tomsk State University of Control Systems and Radioelectronics. There are compared the results got by different researchers in different countries and given the conclusion about the preference of the statistical models for the parameters of the troposphere radio signals prediction. The created base of statistical model´s parameters and experimental data about troposphere characteristics and troposphere radio signals is the background for the synthesis and optimal design of active and passive beyond-the-horizon radars and navigation systems in UHF band.