Digital raster graphic(DRG) and digital line graphic(DLG) are two digital maps that can be taken cheaply, and DLG is a commonest data format now, it is the main data source of GIS.
数字栅格图和数字线划图是可以低成本获取的两种数字地图，而DLG是目前最普遍的矢量数据格式，是GIS的主要数据来源。
Meanwhile the feasibility of integration of "three maps" is discussed from the sameness and differences of surveying of three maps, making digital maps, GIS database and so on.
并从“三图”测绘工作的异同点、数字测图制图、GIS数据库等方面探讨了它的可行性。
Because of their advantages such as small data size, high precision, lossless scaling and easiness to manipulate, vector digital maps are the most important resources in GIS.
其中矢量形式的数字地图由于具有数据量小，精度高，可以无损缩放，便于进行各种操作等优点，是GIS中最重要的资源。
应用推荐