Preliminary studyon electronic map based on surface of ellipsoid

Map carrier not only decides the storage mode of map information, it also has important influence on mathematic foundation and expression mode of geographical information. Based on analysis of the limitations lying in the flat map, this paper introduces the concept of the digital map and electronic map on ellipsoid surface, elaborates on the superiority. The paper investigates the fundamental method of drawing, display and analysis of the digital map on ellipsoid surface farther. Compared with conventional map mode, the digital map on ellipsoid surface is a new concept, it fits the spatial data visual mode based on geographical features superlatively well and suits the people’s cognitive and thought habit who regards earth surface as a ellipsoid; it carries out a reform of expression mode of the existing digital map, and will explore the analysis function and application scope of electronic map and digital map effectively.