Bessel ellipsoid
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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 in 1841 by
astro geodesy). The dimensions of the Earth ellipsoid axes were defined by logarithms in keeping with former calculation
methods.
The Bessel and GPS ellipsoids
The Bessel ellipsoid fits especially well to the geoid curvature of Europe and Eurasia. Therefore, it is optimal for National survey networks in these regions, although its axes are about 700 m shorter than that of the mean Earth ellipsoid derived by satellites.
Below there are the two axes a, b and the
WGS84 are shown, which is mainly used for modern surveys and the GPS
system.
- Bessel ellipsoid 1841 (defined by log a and f):
- Earth ellipsoid WGS84 (defined directly by a and f):
- a = 6378137.0 m
- f = 1 / 298.257223563
- b = 6356752.30 m.
Usage
The ellipsoid data published by Bessel (1841) were then the best and most modern data mapping the
International ellipsoid 1924. All of them are influenced by geophysical effects like vertical deflection, mean continental density, rock density and the distribution of network data. Every reference ellipsoid deviates from the worldwide data (e.g. of satellite geodesy
) in the same way as the pioneering work of Bessel.
In 1950 about 50% of the European
Krasovsky ellipsoid
of about 1940.
As of 2010 the Bessel ellipsoid is the geodetic system for Germany, for Austria and the
.See also
- Geodesy
- WGS 72
- WGS 84
- Gauss–Krüger coordinate system
- Helmert transformation
- Hayford ellipsoid
References
- ISSN 0004-6337.
- ^ Viik, T, F. W. Bessel and Geodesy, vol. Struve Geodetic Arc, 2006 International Conference, The Struve Arc Extension in Space and Time, Haparanda and Pajala, Sweden, 13–15 August 2006, pp. 8–10
- ^ "Formulas and constants for the calculation of the Swiss conformal cylindrical projection and for the transformation between coordinate systems" (PDF). swisstopo. 2016. p. 5. Archived (PDF) from the original on 2019-12-05. Retrieved 2021-09-25.