The analysis of the selected data from Polish Active Geodetic Network stations with the view on creating a model of vertical crustal movements

Up to now, the maps and models of the vertical crustal movements on the territory of Poland were created on the basis of data from 1st class precise levelling. Apart from levelling data, the vertical movements can be determined using satellite data. The present system of reference network has been operating in Poland for 6 years. It enables the determination of the model of vertical crustal movements on Polishterritory on the basis of satellite data. The high credibility of levelling data is evaluated by a number of control procedures and statistical evaluation before and after adjustment, as well as during the measurement activities. The type of stabilisation allows for certainty as well (secular points, buildings of a specific stability, ground survey markers, above ground survey markers). Reference stations, due to the fact that they require an open horizon, are located on high buildings. The choice is conditioned by a number of factors. Moreover, the very structure of a station may influence the final result. The specificity -advantage or disadvantage -of satellite measuring is a permanent observation of the height changes recorded by a reference stations. All changes are recorded, even the slight ones that are not related to the dynamic changes of the Earth's crust. The purpose of this article is to evaluate the measuring data, being the periodic (diurnal) changes of the height between the chosen stations of the ASG-EUPOS system. The evaluation was conducted with the use of statistical methods.