Comparative analysis for refractivity of GNSS decimeter radio waves by radio measurements and by using radiosonde

The paper presents the results of a study of the radio waves refractivity vertical structure using network of seven ground receivers for GPS and GLONASS located in Kazan. 24-hourly behavior of refractivity at altitudes of 100 m, 4,500 m and 11,500 m was obtained for August 18, 2009. The results are compared with the radiosonde data. It is shown that the correlation coefficient of the results retrieved by radio tomography using measurements of Kazan receivers for GPS and GLONASS and radiosonde data is about 0.9.