The Precise Point Positioning (PPP) analysis technique adapted for monitoring of moderate high-rate coordinate variations from GPS observations is applied for measuring actual displacements related to earthquakes. Two approaches are examined: kinematic PPP which is suitable for larger displacements and analysis of residuals from quasi-static PPP which is suitable for detection of minor displacements. Results from simulated horizontal movements of GPS antenna as well as analyses of 1 Hz GPS data from M 9.0 Sendai earthquake, M 6.3 L’Aquila earthquake and M 4.3 Tatabanya earthquake are shown. Our experiments proved the ability to measure dynamic seismic-related short-term coordinate variations at sub-centimetre level with PPP and to detect both strong and weak seismic signals using GPS satellites observations., Ján Hefty and Ľubomíra Gerhátová., and Obsahuje bibliografické odkazy
The paper is focused to the analysis of permanent and epoch-wise GPS networks extending over the region of Slovakia. We considered almost all available GPS data measured in Slovakia and its close surroundings over the period of last 17 years. Our analysis is based on combination of homogenized permanent and epoch-wise network solutions leading to the ITRF2005 related coordinates, velocities and their global covariance matrix. Estimated velocities were further reduced for APKIM2005d plate motion model and submitted to the velocity filtering and smoothing using the least square collocation approach. The obtained homogenized intra-plate velocity field is then used for the surface deformation analysis. The final and partial results of this procedure are discussed in order to extend information about recent regional geo-kinematics of Slovakia., Ján Hefty, Linda Hipmanová, Ľubomíra Gerhátová, Miroslava Igondová and Branislav Droščák., and Obsahuje bibliografii
Series of repeated epoch-wise GPS campaigns performed in Central European region are used for estimation of site velocities. The main features of campaign processing and combination of network solutions are outlined. The velocities obtained from epoch observations within the Central Europe Regional Geodynamic Project covering the 11-year time span are compared at some sites with velocities derived from permenent GPS observations., Ján Hefty and Ľubomíra Gerhátová., and Obsahuje bibliografii