Miesto GIS bazinio žemėlapio sudarymas stereofotogrametriniu metodu

Abstract

The Geodesy Institute of Vilnius Technical University is accomplishing works on making the basic digital map for city Vilnius. Topographic databases are being formed. In constructing an appropriate specification the GIS requirements and the possibility to identify the planimetric features in stereomodel without the field interpretation were taken in account. Essentially an accurate map compilation technology is applied and further improved. The planimetric absolute accuracy for defined features is predicted to be 20 to 30 cm. Soon the databases shall be supplemented by information of the engineering installation networks. These works and the technical aid are partly sponsored by the Government of Norway. The map is constructed by digital photogrammetric approach applying the stereodigitalisation of the features. The aerophotography was taken at scale of 1:6 000 by the Norwegian AO Fjellanger Widerøe on an area of 250 km2. For determining the space positions of the air stations for photographs the kinematic GPS system was used. The aerotriangulation was constructed in blocks amounting to 340 photographs in a unit. Adjustment of triangulation blocks was performed according to the program NLHBUNT installed by Norwegian specialists. The digital map is digitalised using the computerised analogue photogrammetric instruments such as Wild autograph A8 and Santoni-Gallileo stereosimplex IIc.