| Abstrakt: |
Abstract: The evolution of the Global Navigation Satellite System (GNSS) permitted the development of GNSS meteorology. The present article is studying the impact of ambiguity resolution and final data products on Zenith Wet Delay (ZWD). Th e data products were provided by different Analysis Centers (AC’s) like, European Space Agency (ESA), International GNSS Service (IGS) and Jet Propulsion Laboratory (JPL). The estimation of the ZWD was made by using the Precise Point Positioning (PPP) technique. For the study we used eight European IGS stations. In the first part of the analysis the effect of data products from different AC’s was analyzed. B y differentiating the results of the ZWD in which we have used the data products from IGS and ESA, the ZWD presented a variation of 2 cm with a maximum of 3.2 cm on GANP station. The largest difference on the ZWD standard deviati on by using precise ephemeris and clock dat a from different AC’s were 0.2 mm, when the IG S and JPL data product were used. Using the data products from IGS and ESA, in terms of estimated ZWD standard deviation, they were in agreement of 0.1 mm. The effect of the ambiguity resolution, by using the data products from the same AC’s revealed a relatively different behavior of the ZWD, only the JPL data products between the solved and unresolved ambiguities presented a similar behavior. The common part in all of the processing strategy, for the ambiguity resolution, was the use of phase biases provided by JPL. |
