The purpose of the given work lies in the studies of the atmospheric precipitable water vapour (PWV), based on the processing of aerological and GNSS (Global Navigation Satellite System) measurements, as well as the comparing of PWV values, determined according to the data of aerological and GNSS stations, located both in temperate and tropical latitudes. Methodology. The algorithm for determination of precipitable water vapour, based on GNSS observations, is divided into several stages: 1) the total tropospheric delay is determined by the basic equation of code or phase pseudodistances of GNSS measurements; 2) select zenith tropospheric delay (ZTD) values at the time of GNSS observations [ftp://cddis.gsfc.nasa.gov/gps/products/troposphere/new/]; 3) according to the analytical Saastamoinen model, the hydrostatic component of the zenith tropospheric delay (ZTD) is calculated;
4) according to the ZTD values and hydrostatic component, the wet component values of the ZTD are obtained; 5) the conversion from the wet component to the integrated water vapour (IWV) component and the precipitable water vapour PWV is realized. The IWV and PWV values are also defined by upper-air sounding data. Results In the course of the performed research, the ZTD components and the PWV values were determined. A comparative characteristics of the present values was carried out, which were defined according to the data of both aerological and GNSS stations. Generally, the accuracy of the hydrostatic component of the ZTD determination is about 10 mm, and the accuracy of the wet component definition of ZTD, deducted from GNSS measurements, is approximately 20 mm. The PWV values mainly vary by analogy to the values of wet component of ZTD, and the accuracy of its definition reaches 3 mm. Novelty and practical significance. For the first time, simultaneous studies of the ZTD and its components and the water vapor content at five stations in the middle latitudes and three stations of the tropical zone were conducted. The obtained results can further be used in the studies of changes in climatic processes.
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