tesseral surface harmonic
1geoid — geoidal, adj. /jee oyd/, n. 1. an imaginary surface that coincides with mean sea level in the ocean and its extension through the continents. 2. the geometric figure formed by this surface, an ellipsoid flattened at the poles. [1880 85; < Gk… …
2Spherical harmonics — In mathematics, the spherical harmonics are the angular portion of an orthogonal set of solutions to Laplace s equation represented in a system of spherical coordinates. Spherical harmonics are important in many theoretical and practical… …
