Global 3D\|Grids Based on Great Circle Arc QTM Sphere Octree and Unequal Octree

We describe the principle of QTM sphere solid partition based on great circle arc octree and unequal octree and the features of their grid system, derive the volume formula of grid cells, discuss the size of the volume deformation among the grid cells at the same layer and in the same column，and compare them with degenerated octree subdivision on the shape deformation, and explain the sphere octree encoding and decoding methods. The results show that， at the full use of great circle arc characteristics, global 3D\|grids based on QTM sphere octree of great circle arc have a simple shape, arranged in neat and moderate deformation. It can be used for the organization and management of spatial data of integrated earth.