Glazovsky Institute of Geography, Russian Academy of Sciences, Moscow, Russia *macheret2011@yandex.ru Received September 1, 2016 Keywords: dry snow, radio echo sounding, radio wave velocity, snow cover, snow density, snow structure, wet snow. <...> Summary In recent years, ground-penetrating radars are widely used for measuring thickness and liquid water content in snow cover on land and glaciers. <...> The measurement accuracy depends on radio wave velocity (RWV) adopted for calculations. <...> The RWV depends mainly on density, water content and structure of the snow cover and ice layers in it. <...> The density and wetness of snow, and its structure can be estimated from data on RWV, using the available experimental and theoretical relations. <...> Satisfactory results can be obtained using the Looyenga’s (1965) equations to estimate the density and wetness of snow cover, and equations of van Beek’s (1967) showing the distinction between RWV speeds velocities in snow cover and ice layers with different prevailing orientation and sizes of air or water inclusions. <...> In ice with density 700 kg/m3 effect of air inclusions orientation on differences in RWV is reduced to 5 m/µs. <...> Therefore, considerable attention should be given to accuracy of the RWV measurements in dry and wet snow cover and its individual layers. <...> Поступила 1 сентября 2016 г. Принята к печати 26 декабря 2016 г. Ключевые слова: влажный снег, плотность снега, радиоэхозондирование, скорость распространения радиоволн, снежный покров, структура снега, сухой снег. <...> Представлены результаты расчётов скорости распространения радиоволн в снежном покрове в зависимости от плотности, влажности, структуры снега и прослоек в нём льда по разным эмпирическим и теоретическим <...>