A Method of Constructing Approximate Equal-Area Diamond Gird

The Equal-area characteristics of the global discrete gird have contributed to the improvement of spatial analysis precision. In this paper, a method for constructing approximate equal-area diamond girds is proposed based on the octahedron using the Snyder projection. Area deformation rules for diamonds are analyzed and the spatial distribution of diamond grids with different area deformations is presented. The analysis results indicate: 1. area deformation ratios of most cells in diamond grids are between-0.25% and 0.25%; when subdivision level is equal to six, while the area deformation ratios of 99% of diamond grids are between-0.25% and 0.25%; 2. three girds with the maximum area deformation are near to center point of subdivision surface of the octahedron, while the spatial distribution of grids with different area deformations is symmetrical.