The Geodetic Reference System 1980 (GRS80) consists of a global reference ellipsoid and a normal gravity model.

Normal gravity g = grad!U at the surface of the ellipsoid is given by the closed formula of Somilgiana, where the constants ge and gp denote normal gravity at the equator and at the poles, and F denotes geographical latitude.

2024年6月18日 · GRS80 and NAD83 are geodetic reference systems used for mapping and surveying. GRS80 is a global reference system, while NAD83 is used in North America. They provide coordinate systems and control points for accurate positioning and spatial data analysis in their respective regions.

2015年9月8日 · GRS80 is a geodetic reference system consisting of a global reference spheroid and gravity field model. WGS84 is an Earth-centred, fixed terrestrial reference system and geodetic datum. WGS84 describes earth’s parameters including: • Semi-Major Axis : 6378137.0m • Flattening Factor : 298.257223563. The difference between them is?

2024年7月29日 · Storing only these four values and computing derivative values on the fly is the most rigorous way to adopt and use GRS80. The equations defining any derived value cannot yield a number with an exact value (that is, all digits are known).

2017年4月14日 · GRS80 is an ellipsoid/spheroid, not a true geodetic datum / geographic coordinate system. If that's all that is listed (particularly for GRIDs or coverages), the software will create a "GRS80-based" geographic coordinate system.

[geodesy] Also known by the acronym GRS80. The standard measurements of the earth's shape and size adopted by the International Union of Geodesy and Geophysics in 1979; an ellipsoid that is essentially identical to the World Geodetic System of 1984 ellipsoid.