中文摘要：

球面离散网格只进行地球表面剖分，而球体退化八叉树网格（SDOG）可对整个球体空间进行多层次连续的三维递归剖分，且网格大小均匀、变形稳定，适合作为全球三维空间基础框架。该文研究SDOG的编码与解码问题，剖析了SDOG网格编码的原理，提出两种网格编码方法，即单层次退化Z曲线填充编码（SDZ）和多层次退化z曲线填充编码（MDZ），设计了相应的编码与解码算法。通过实验比较了SDZ、MDZ和QuaPA主码在编码效率、解码效率及编码长度方面的差异，结果表明MDZ是一种优异的多分辨率动态网格编码方法，可服务于基于SDOG的全球三维空间基础框架。

英文摘要：

The Global Discrete Grid （GDG） only do spatial division on the Earth surface, but the Sphere Degenerated-Octree Grid （SDOG） do hierarchical continuous three dimensional spatial division on the whole Earth including its surface,inside and outside space. SDOG is nice to be a general three dimensional fundamental framework of the Earth. In this paper, the coding and decoding principles for SDOG are studied. The coding principle for SDOG is analyzed, and two coding methods, viz. single hierarchy degenerated-Z curves coding （SDZ） and multi-hierarchy degenerated Z curves coding （MDZ） are presented. The related coding and decoding algorithms for SDZ and MDZ are designed. Furthermore, the coding efficiency, decoding efficiency and code length are compared between MDZ,SDZ and QuaPA via experimental test. The test shows that MDZ is an excellent method for the multi solution dynamic 3D grid, and can serve the SDOG-based three dimensional fundamental framework of the Earth.