An Evidence of Hydrological Signal in GPS time series in Poland

Rajner, Marcin; Liwosz, Tomasz; Rogowski, Jerzy B.
Warsaw University of Technology, Poland, mrajner@gik.pw.edu.pl

Currently well known influence of continental water loading on surface displacement can be measured by various geodetic methods. Among others satellite positioning is the most robust and easily available technique. In this paper we compare GPS measured position changes with deformations computed on the basis of global water storage models. We used GPS data from several Polish permanent sites with long-time measurement period available, applying Precise Point Positioning method using consistent IGS products. Results were corrected for other geophysical signals (tectonic, atmospheric). An overall good agreement (specially for height component) was found. Paper deals also with possibility of reduction of predominant yearly hydrological signal from positioning results. Simple model appropriate for studied area is introduced and its accuracy is estimated.