With the development of remote sensing technologies, computer friendly systems for the display and analysis of global geospatial information become more and more important. This paper concerns a method for computer representation and manipulation of global data based on multi-resolution subdivisions of regular polyhedra. A simple and efficient indexing of the cells of such a subdivision, called A3-coordinates, is introduced. These can be used to encode the 18 · 4n+1 - 32 cells at the nth level of resolution of the octahedral aperture 4 hexagonal discrete global grid using 2n + 3 bits.