The aim of the thesis was to compare the calculations of zenith tropospheric delay, computed within the meteorological model, with an independently acquired calculation of three GNSS data processing methods. Data analysis was done in the absolute and relative mode of determination. Using absolute mode of zenith tropospheric delay computation we computed the differences between the computed zenith tropospheric delay with the meteorological model ALADIN, taken as a reference, and results of zenith tropospheric delay computation on the basis of GNSS observations processing with geodetic methods (PPP, Bernese GNSS Software, network SIGNAL). The absolute zenith tropospheric delays values of chosen reference station we used for calculation of the relative tropospheric delay. Thus obtained values of differential zenith tropospheric delay we compared with the values obtained from the meteorological model. On the basis of calculated differences the mean value of the differential tropospheric delay and the standard deviations were calculated. These data were then evaluated. The obtained values of zenith tropospheric refraction show a high level of conformity between values obtained on the basis of GNSS data processing with the meteorological model, particularly in the relative mode using with PPP method and Bernese GNSS Software.