some metric problems on the global grid systems

Abstract

The Discrete Global Grid Systems (or the global position location framework) is a kind of scientific and concise spatial reference system, which is the discretization, accurate and systematic representation of the earth information data. In recent years, with the development of GPS and Beidou satellite system and the process of globalization, the global metric and accuracy of spatial analysis should be pay more attention by people. In this paper, first, for the progress and insufficiency over recent years of the earth grid research, the author discusses several quantity issues include:the integrity of meshing, logical consistency, and some related problems. Then regarding the questions of position and metric, the author points out that the Earth is the target object of meshing its characteristics of metric space. The revolutionary demand of "3D structure and centimeter level accuracy" will have a significant impact on global GIS system. Next, the 3D meshing approaches to the ellipsoid of the earth are stressed, and the author also introduces the corresponding experiments and theoretical approach in map algebra on the 3D earth meshing. Finally, this paper reaffirms that the 3 sets of (B, L, H) orthogonal surface should be the most appropriate way on metric for the Earth meshing.