摘要
全球离散格网系统是一种新型的地球空间数据模型,是平面格网模型在球面上的扩展。由于六边形的几何结构优势,经常被用于球面离散格网的构建。在平面格网向球面映射过程中,因球面的不可展性,格网上的距离和方向都会发生巨大变化,导致矢量数据球面格网化绘制的精度无法得到保证,这成为矢量数据在全球离散格网显示的一个重要瓶颈,直接制约了球面格网上空间度量关系的建立。本文针对全球六边形离散格网上矢量线数据的绘制问题,研究了平面-球面映射过程,对直线方向影响的统计变化规律,对矢量线数据的格网化表达进行了精度控制,使得平面格网上的矢量绘制方法,能在球面格网上进行高精度的绘制,并保证矢量数据的球面格网绘制误差严格控制在当前层次格网的一个单元内,为格网化数据的高精度显示和格网空间度量的建立奠定了理论基础。
The Discrete Global Grid System （DGGS） is a new type of global spatial data model and is the exten- sion of the plane grid on a sphere. Hexagon is usually used in the construction of DGGS for its advantageous geometric structure. Since sphere is unextended, in the process of plane grid mapping, the distance and direction of the grid will change greatly. As a result, the accuracy of drawing vector data in the global grid cannot be guar- anteed. This has been a critical choke point for the display of vector data in DGGS and has directly restricted the establishment of spatial measurement relationship on a spherical grid. In order to solve the drawing problems of vector line data in hexagon DGGS, this paper has studied the distortion regularity that the plane-sphere mapping process affects the linear direction, and control the accuracy of vector line data grid transformation. As a result, the vector drawing method on a plane grid can also be adopted to deal with high-accuracy drawing on a spherical grid, and it guarantees that the spherical grid drawing errors of the vector data can be controlled strictly in one cell of the current layer＇s grid. This paper also lays the theoretical foundation for high-accuracy display of grid transformation data and the establishment of spherical grid spatial measurement.
出处
《地球信息科学学报》
CSCD
北大核心
2015年第7期804-809,共6页
Journal of Geo-information Science
基金
国家自然科学基金项目(41201392
41271391
40930104)
中国博士后科学基金项目(2013M542456)
关键词
全球离散格网
六边形
控制精度
矢量绘制
多面体投影
discrete global grid system
hexagon
accuracy control
vector drawing
polyhedral projection
