Gradient of Radio Refractivity in Troposphere

摘要

The dependence of radio refractivity on height above the Earth's surface has been examined. The method proposed by International Telecommunication Union has been used. The gradient of radio refractivity has been analyzed over Kaunas, the city of Lithuania. This location was chosen considering our previous studies, which showed that the yearly variation of N is highest in Kaunas, in comparison with other localities of Lithuania. The local meteorological data, which was measured near the ground and also at the different heights above the Earth's surface, have been used in calculation of radio refractivity. It was concluded, that the super-refraction of radio waves and ducting phenomenon could occur at the end of April in Kaunas.