Turimų planų naudojimas Vilniaus GIS baziniam žemėlapiui sudaryti

Abstract

The peculiarities of constructing a basic digital map for city GIS using digital data from existing plans at a scale of 1:500 are investigated. Digitisation of geodetic elevation points and buildings for experiment in a small area was carried out for facilitating the establishment of a digital map by stereophotogrammetric approach. Analysis of data obtained from digitisation in the existing plans and from stereophotogrammetric digitisation using the computerised analogue photogrammetric instruments such as Wild autograph A8 and Santoni- Gallileo stereosimplex lie is presented. The number of points which values of digitised elevations and stereodigitised elevations do not coincide at a required accuracy are about 5%. Import of digitised high points to stereophotogrammetric data base facilitates and speeds up the construction of digital map both in woodlands and in the territories built on by high buildings; digital data are only information about the relief. The experiment shows that digitisation of buildings for digital stereophotography is unfit for use. The outlines of buildings do not coincide at a required accuracy and checking, editing also takes up too much time. Digitisation of buildings is necessary only in wooded territories.