# Discrete Global Grid System (DGGS)

Discrete Global Grid System (DGGS) is a spatial reference system that uses a hierarchy of equal area tessellations to partition the surface of the Earth into grid cells or their analogous lattice points. In this way, information recorded about phenomena and observation measurements at a location can be easily referenced to the explicit area of the associated cell, integrated with other cell values, and provide statistically valid summaries based on any chosen selection of cells. In order for a grid based global spatial information framework to operate effectively as an analytical system it should be constructed using cells that represent the surface of the Earth uniformly. With equal area partitioning, spatial analyses can be replicated consistently anywhere on the Earth independently of resolution or indeed scales.

DGGS uses solid polyhedrons e.g. tetrahedrons, cubes, octahedrons to model the earth, these tessellations are inversely projected to create the reference system. So, DGGS intension is to define the required criteria and core functional algorithms to support operations of a conformant DGGS and not to intend to establish a single DGGS as a standard reference.

There are five common simple forms of DGGS, they are: tetrahedron, hexahedron, octahedron, dodecahedron, icosahedron.

Please refer to the following web pages for more inforamtion: