GRS-80

The Geodetic Reference System 1980 (GRS-80) is a globally recognized reference ellipsoid used as the foundation for modern geospatial datums, including WGS 84 and NAD83. It provides a highly accurate mathematical model of the Earth as an oblate spheroid, defined by key parameters such as the equatorial radius, polar radius, and flattening. GRS-80 was developed to improve the precision of global positioning and mapping systems by offering a consistent and standardized representation of the Earth’s shape. Unlike a perfect sphere, it accounts for the Earth’s equatorial bulge caused by rotation, making it more realistic for geodetic calculations. This ellipsoid supports accurate coordinate referencing, distance measurement, and spatial analysis across global and regional systems. It plays a critical role in satellite navigation, GIS applications, surveying, and geodesy by ensuring compatibility and uniformity in geospatial data worldwide.