Вісник Астрономічної школи (Oct 2017)
Estimation of velocities using GNSS observations in the GNSS Data Analysis Center of GAO NASU for further geodynamical studies
Abstract
Global satellite navigation systems (GNSS) has firmly entered not only in the daily life of society, but also widely used in various fields of scientific application. The possibility of conducting continuous observations at permanent GNSS stations, which do not depend on weather conditions, allowed to accumulate long periods of observations. All this led to the acquisition of precision time coordinate with accuracy of several millimeters. One of the first steps in the study of the local level of the crustal deformation is the estimation of the values of the displacement velocities of the GNSS stations. One of the simplest and most widespread ways of representing the horizontal movements of the earth's surface occurring within the region under study is the acquisition of a velocity field. GNSS data analysis center of GAO NASU received estimates of velocity vectors for 233 GNSS stations (in coordinate system IGb08), 202 of which are located in Ukraine. The maximum assessment period was from December 7, 1997 – January 28, 2017, or 6,993 days (approximately 20 years). The rate estimation is based on GNSS observations of state, academic, university and commercial networks of Ukraine. The velocity vectors were obtained using the Bernese GNSS Software Ver. 5.2 (ADDNEQ2 and FODITS software modules were used) recommended by the GNSS Data Analysis Centers, in particular by the EUREF European Center for research of this type. The obtained estimates of the velocity vectors fully coincide with the movement of the Eurasian lithospheric plate. For further use in studies on the deformation of the Earth's crust, each GNSS station should be thoroughly tested for possible effects (caused by the operation of the apparatus, human factor, etc.), as well as to satisfy the minimum observation period of three years.
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