The study of geospatial data extraction based on MicroStation

Geospatial data extraction, which extracts geometric information and attributes information from the graphical data file, attributes database to binary point, line, surface storage format to form an intermediate file. According to the software demand the middle point of the document line elements are separated and stored in accordance, then the elements are placed in corresponding layers. In essence, geospatial data extraction is actually the inverse process for geospatial data symbolization. In the digital map production, it both meet the needs of hard-copy map (such as map printing, plotter output etc.), but also meet the geospatial geographic data warehousing, data format conversion and other demands. The realization of geospatial data extraction in MicroStation is analyzed and the implement methods are given in this paper.