GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY

Abstract

The aim of this work – research of topological inconsistencies during adjustment and junction of adjacent map sheets of digital topographic maps of scale 1:50000 with the use of rigorous analytical geodetic methods on the reference ellipsoid in the geoinformation environment. The research analyzes the phenomenon of topological inconsistencies of frames of adjacent digital topographic maps of 1:50000 scale within the zones of Gauss-Krueger projections and the feasibility of transition to rigorous analytical geodetic methods in the geoinformation environment during the creation of the topographic database “The Main state topographic map” by determining the differences between the vertices of the frames of digital topographic maps at a scale of 1: 50000 at the boundaries of the projection zones. This phenomenon was discovered during work at the state enterprise “Research Institute of Geodesy and Cartography”. The dependences are shown and analyzed, which show the changes in the distances between the vertices of the frames of adjacent map sheets of scale 1: 50000 in longitude and latitude. These values range from 1 mm to 8 mm, which leads to topological inconsistencies in the form of gaps and overlaps of adjacent map sheets. These gaps and overlaps complicate the process of adjustment of map sheets and make it impossible to automate the process of the junction of features into the topographic database. The scientific novelty of the research is to justify the use of rigorous analytical geodetic methods and tools instead of analog cartometric and standard methods of instrumental GIS; the use of a reference ellipsoid, not just cartographic projections, a spheroid or a sphere. The practical significance of research is the use of rigorous analytical geodetic methods that significantly minimize the values of gaps and overlaps, as the establishment of tolerances for these values does not automate the process of correct adjustment and junction of map sheets. The performed research can be used to create the topographic database “The Basic topographic map scale 1: 10000”, during the creation and updating of geospatial data in the geoinformation environment and the implementation of geodetic methods to determine the cartometric characteristics of features using GIS. Given the results of research, we can conclude that the present stage of application of geographic information systems in topographic and geodetic activities requires increasing the level of data topology and accuracy of all cartometric methods, which leads to the transition to extremely rigorous analytical geodetic methods directly on the reference ellipsoid.