Vilniaus miesto grafinių duomenų papildymas topologiniais ryšiais

Abstract

Complicated objectives, such as automated map drawing or analysis of geodata, require to define exact relationships between graphic objects , ie to create topologic relationships. Topological data structuring provides additional information to the geodatabase (GDB). Topological data structuring shows which cartographic objects are linked in a logic way. Before establishing topological relationship, it is important to develop suitable GDB structure which would allow to achieve planned objectives. Four main structures of GDB can be highlighted: topical, territorial, administrative, and qualitative. The main lines of topical structure: separate continuous buildings, ground, altitudes, lines GDB for the whole city. GDB is divided according to the sizes of map-cases, airtriangulation models or city territories. Administrative structure has specific GDB purpose eg GDB plots, environment protection GDB, agriculture GDB, topographical data GDB, engineering network GDB. Qualitative structure has GDB divided according to qualitative characteristics (photogrammetric data, digital data, scanned data). For Vilnius city, topographical-engineering GDB forming data are taken from various sources of information, such as air-photography, map-cases, discovered views. Each information source used has its qualitative and territorial characteristics. In forming city’s topographical-engineerical GDB, it could not be chosen only one of the structures of GDB. The main feature of Vilnius topographical-engineering GDB structure is a homogeneity of the same quality data and uniform specification of data, which allow to distinguish main features of thematic and quality structure. The GDB administration structure defines distribution of duties and responsibilities among institutions. From this point of view Vilnius topographical-engineering GDB is in the influence sphere of the Department of Architecture and Building.