Gaussian grid


A Gaussian grid is used in the earth sciences as a gridded horizontal coordinate system for scientific modeling on a sphere. The grid is rectangular, with a set number of orthogonal coordinates.
At a given latitude, the gridpoints are equally spaced. On the contrary along a longitude the gridpoints are unequally spaced. The spacing between grid points is defined by Gaussian quadrature. By contrast, in the "normal" geographic latitude-longitude grid, gridpoints are equally spaced along both latitudes and longitudes. Gaussian grids also have no grid points at the poles.
In a regular Gaussian grid, the number of gridpoints along the longitudes is constant, usually double the number along the latitudes. In a reduced Gaussian grid, the number of gridpoints in the rows decreases towards the poles, which keeps the gridpoint separation approximately constant across the sphere.

Examples of Gaussian grids