全球离散格网系统结构要素一体化编码与生成方法

全球离散格网系统是用于构建数字地球的一种有效空间数据组织框架,其中,三角形、四边形和六边形等多种单元形状的格网已在各领域广泛应用。各具特色的格网满足了各专业领域的应用需求,但也因其格网类型的差异而阻碍了跨领域的数据共享,同时单一格网在面向多领域科学问题上存在一定的局限性,因此实现多类型离散格网系统之间的互操作功能具有重要的研究意义。不同类型格网结构要素相互转换机制的建立,是实现异构格网数据集互操作的关键。本文针对这一问题,首先,研究了三类全球离散格网系统结构要素的统一特征及格点和格元的相互关系,进一步揭示了其等差圈层的分布模式;其次,以球面四元三角网为例,建立了格点的等差圈层编码,随后,根据格点与格元的关系提出了基于格点索引的全球离散格网一体化编码与生成方法;最后,利用该方法生成了河南省地表高程的格点模型、三角形格网模型、菱形格网模型和六边形格网模型,并验证了其正确性和可行性,为全球离散格网的互操作机制提供一种新思路。

The Uniform Encoding and Generation Method of Structure Elements of Discrete Global Grid Systems

As the supporting technology of the digital Earth platform, the Discrete Global Grid System is a frontier and hotspot in the field of Earth information science and has been the subject of abundant researches. It can subdivide an ellipsoid without changing its grid shape. Each subdivision level has a regular structure, so there are strict transformation relations between grids at different subdivision levels, which provides a unified expression model for the fusion of geographic data with arbitrary distribution and different scales. In Discrete Global Grid System, triangular, diamond, and hexagon grid cells are widely used. Although each grid system has its own characteristics and can meet the application needs in various professional fields, but the differences among different grid systems inevitably hinder cross-field data sharing. Different grid systems have their own advantages and disadvantages in solving different scientific problems, and their corresponding spatial operation and computational analysis also vary in complexity. Furthermore, because the data representation of a single type of grid division is limited in multi-domain scientific problems, the development of an interoperation function of a multi-type Discrete Global Grid System is of great significance. The key to realize the interoperation of heterogeneous grid data sets is to establish a mechanism for the interconversion of different types of grid structure elements. Aiming at this problem, this paper studied the unified characteristics of structural elements in three Discrete Global Grid Systems, the relationships between vertices and grids, as well as the distribution patterns of the arithmetic layer. Secondly, taking the Quaternary Triangular Mesh as an example, the arithmetic layer encoding and generation method of the vertices were established while the uniformity of the vertices was analyzed. Then, according to the relationships between the vertices and grids, this paper proposed a uniform encoding and generation method for Discrete Global Grid System based on the vertices index. Finally, using this method, we generated the vertex model, triangle grid model, diamond grid model, and hexagonal grid model of surface elevation of Henan Province. We further verified the correctness and feasibility of the methods. This study provides a theoretical basis for exchanging, unifying, and standardizing the data in different types of Discrete Global Grid Systems and a new idea for the interoperability mechanism of different Discrete Global Grid Systems.