Bessel ellipsoid

The Bessel ellipsoid (or Bessel 1841) is an important reference ellipsoid of geodesy. It is currently used by several countries for their national geodetic surveys, but will be replaced in the next decades by modern ellipsoids of satellite geodesy.

The Bessel ellipsoid was derived 1841 by Friedrich Wilhelm Bessel, based on several meridian arcs and other data of continental geodetic networks of Europe, Russia and the British Survey of India. It is based on 10 meridional arcs and 38 precise measurements of the astro—geographic latitude and longitude (see also astro geodesy). The dimensions of the ellipsoid axes were defined by logarithms in keeping with former calculation methods.