Global Equal-area Quadtree Discrete Grid Modeling And Coding System

As space technology and information technology continues to progress, especially inremote sensing and global positioning technology rapid development, so that we can obtainmulti-resolution, massive, real-time observational data of the Earth and its various resourcesand environment and social phenomena. But how to effectively express and manage hugeamounts of data on the global has become a major problem faced by domestic and foreignacademia and departments. Global spatial information grid is based on such background,and immediately became one of the hot fields of geological and other related discipline athome and abroad.Global discrete grid is a kind of qualified nets that based on the sphere which caninfinite subdivision, but do not change its shape. When subdivided to a certain extent, it canachieve the purpose of simulation the surface of the earth. It has different levels and globalcontinuity, not only avoids the plane projection which brings the angle, the length and thearea of the deformation and its spatial data of discontinuity, and overcomes the limitations ofGIS application restraint and not qualitative, namely, in any position on the earth of the gainof multi-resolution (different precision) spatial data can regulate to express and analysis, andthe precision is determined multi-resolution operation; It can fundamentally solve planemodels in the global multi-scale spatial data management data fracture, deformation andtopological inconsistencies, and can easily be in the grid computing environment to realizethe integration of spatial information resources sharing, and utilization.This paper introduces the current domestic and foreign several global discrete grid andits hierarchical subdivision structure and encoding method, and based on analyzing the areaformula of spherical crown and band, the article proposes the modeling method for theglobal grids with equal-area and quadtree structure, elaborates the delimiting mechanism,formulate the number system, constructs the formula from the number to longitude andlatitude of the center and from longitude and latitude to the number，assumes the aspects inuse. The grids have uniform shape and area, edges parallel to meridian and parallel, andaccord with Goodchild discrete global grid evaluation standard.