engleski

Quality analyses of the geodetic control for monitoring vertical displacements of Dubrovnik city

For the deformation analysis of natural or man-made structures it is very important to analyze the quality (accuracy) of established geodetic control being the base for all surveying activities. In this article the quality analysis of the geodetic control is shown on the example of vertical geodetic network established for monitoring vertical displacements of the Old City of Dubrovnik. This leveling network was established after the earthquake in 1979 which caused significant damage. Seismically active area where the city was build was one of the main reasons for the needs of monitoring. Due to the specific and extremely unfavorable conditions because of land configuration and characteristics of the the city's architecture, great attention should be paid to developing a quality project of the network and planning of survey that would ensure high-precision measurement results. For these reasons, before any interpretation of certain displacements, it was necessary to examine the quality of geodetic control. The main two elements of geodetic control quality are its precision and reliability. In this paper new standards for reporting the precision of positioning geodetic control points prescribed by international standards in the field of geospatial information that have been accepted as European, i.e. Croatian standards (ISO 19113) will be presented. In analyzing reliability of the network, traditional Baarda's approach is used. The adjustment of the network was performed using software Columbus 3.8. This software, as its output, shows all the precision and reliability measures described in this paper.

deformations; displacements; geodetic control; accuracy standards;

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