地球剖分网格(或全球位置定位框架)系一种科学简明的空间参考系统,是地球信息数据的离散化、准确化、系统化的表现,这是地理信息科学和数字地球中重要的基础性问题,是全部地理计算的源头和归宿。近年来,随着GPS、北斗等卫星系统日趋发展和全球化应用,此相关于全球三维位置准确性、度量和全部空间分析准确性等基础问题受到人们高度重视。本文首先针对多年来地球剖分网格研究的进展和不足,提出和分析了网格数据的质量的若干问题,即剖分的完整性、逻辑一致性、准确度和一些相关问题;然后面向剖分中的定位和度量,指出了剖分对象及其度量空间特征,剖析了"3维结构及厘米级准确度"的革命性需求将对GIS体系和剖分科技体系发展产生重大的影响;接着,着重指出地球剖分的椭球三维途径的主体和剖分途径,论述了加强剖分基础理论阐述的内容和意义,并介绍了地图代数在地球剖分基础对象、椭球三维剖分和理论途径和相应试验。最后,课题组认为椭球型、(B,L,H)三组正交曲面剖分是地球剖分工作的正确途径,建议大力强化剖分理论基础研究,发展和完善剖分的标准体系,迅速创建地球剖分试验平台。
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 "3Dstructure and centimeter level accuracy"will have a significant impact on global GIS system.Next,the 3Dmeshing 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 3Dearth meshing.Finally,this paper reaffirms that the 3sets of(B,L,H)orthogonal surface should be the most appropriate way on metric for the Earth meshing.