适应性球体退化八叉树格网及其编码方法

Adaptable Spheroid Degenerated-Octree Grid and Its Coding Method

球体退化八叉树格网(SDOG)为具有经纬一致性、正交、粒度近似、非重叠、多层次性及多分辨率的三维全球空间格网(GSG),有望成为地球系统科学、全球GIS乃至数字地球的空间基础框架,但不便处理半径及球面维度上的分辨率非同步变化问题。该文在SDOG基础上沿某一方向进行独立递归细分,构建了一个能适应非同步变化的多分辨率的球体GSG———适应性SDOG,提出了其耦合退化Z(CDZ)曲线填充编码方法;并以NCEP提供的温度数据为实验,实现了基于适应性SDOG的全球大气温度场三维建模与可视化。结果表明:适应性SDOG具有更好的适应能力,能有效处理分辨率非同步变化问题,提高了SDOG作为全球空间基础框架的应用性能。

Spheroid Degenerated-Octree Grid （SIX）G） is a kind of spheroid Global Spatial Grid （GSG）, which has nice characteristics in longitude-latitude consistency, orthogonality, quasi-uniform, non-overlapping, multi-hierarchy and multi-resolution, and has potentiality to act as the basic spatial reference framework of Earth System Science （ESS）, Global GIS and Digital Earth. However, a huge difference in grid resolution may exist between the radial size and spherical size, which are not easy to be trea ted by SDOG. This paper developed an adaptable SDOG which can solve that problem well by making a refine subdivision along SDOGs radial direction or spherical direction, respectively. A special space filling curve, named Couple Degenerated Z-curve （CDZ-curve） ,was designed to fill adaptable SDOG and to realize the grid coding of adaptable SDOG. With global atmospheric temperature provided by NCEP being an example, the adaptable SDOG was experimentally applied for the global 3D spatial modeling of great resolution difference between radial and surface directions. The experiment shows that the adaptable SDOG has better adaptability for Earth System Science, and makes SDOG be qualified to be the basic spatial reference framework of planet Earth.