Deformation analysis based on GNSS measurements in Tashkent region

This paper presents the results of the GNSS geodetic network deformation analysis in the Tashkent region, as an example of an urban area, where obtaining reliable information for assessing hazard risk is of great importance. A software package in Delphi language has been developed for the assessment of the datum differences between 2009 and 2011 by implementing the 3D Helmert transformation method. The result revealed that there is significant translation and rotation in the network, while the scale of the network remains almost constant during two years period. The area strain was estimated by the finite element method. Most of the Tashkent region can be considered to be in a high compression (negative dilatation) strain state with maximum value -230cl0-8. On the contrary, remarkable positive dilatation strain is concentrated on the coastline of the Charvak water reservoir, where large strain is about 351.l0-8

Processing of GNSS data in Gamit/Globk: On the example of the reference stations of the Uzbekistan network

The article presents the results of processing, a preliminary assessment of the quality of measurements, and the accuracy of the coordinates of the points of the reference network of Uzbekistan (MAGK, FARG, JARQ, and URGA). Observation data of GNSS points were processed using the GAMIT/GLOBK v.10.71 software package by applying standard procedures for position and velocities estimation relating to the ITRF2014 global reference frame. The horizontal velocities of points were compared with the latest versions of global tectonic models such as ITRF 2014, GEODVEL 2010, and NNR - MORVEL 56. Analysis of the point time series confirmed the good quality of the measurements and the accuracy of the processed coordinates in the GAMIT/GLOBK program. The calculated solutions had horizontal coordinates, uncertainties uncertainty, and repeatability, at the level of 1-3.2 mm for horizontal coordinates and 3.2-6.5 mm for height. However, the analysis of the horizontal velocities of points and comparison of the results with global tectonic models confirmed the need for further compaction of the regional satellite network, especially in the western part of the territory, taking into account the new model of modern movements of the region