Krassowski ellipsoid
The Krassowski ellipsoid (named after the Russian geodesist Feodossi Nikolajewitsch Krassowski , often also written Theodor Krassovsky or Krassowskij ) describes a reference ellipsoid for approximating the actual earth figure (see also world network ), which is common in the former Eastern Bloc , especially for the Soviet general staff map , to this day is used.
The ellipsoid parameters calculated by Krassowski are
- Equator semi-axis a = 6,378,245.0 m, flattening of the earth f = 1: 298.3
and can in the table important reference ellipsoid are compared with other ellipsoids, as with the previously for Germany and Austria important Bessel ellipsoid of 1841. Originally, the Krasovsky ellipsoid was as triaxial ellipsoid designed, but because of its complicated to use, it was on two parameters reduced.
application
The Krassowski ellipsoid is particularly adapted to the geoid of Eurasia . Krassowski calculated it in the late 1930s from geodetic measurements, which supplemented the data bases of earlier ellipsoids (Bessel 1841, Hayford 1909 ) with surveying networks and astrogeodetic data from the Soviet Union . It is, like the above. Table shows in quality between its predecessors and the modern values. Only the values from Helmert 1906 are somewhat better globally, but this could only be shown by measurements of satellite geodesy from 1960 onwards.
In the GDR - as in the Soviet Union and all Eastern Bloc countries - the Krassowski ellipsoid was used as the basis for the Gauss-Krüger coordinate system. While in Germany the land surveying offices have switched from the Gauß-Krüger coordinates (Potsdam date, Bessel / Krassowski ellipsoid) to the UTM system with reference to the ETRS89 (system) with the GRS80 ellipsoid since the 1990s , the previous systems in the new federal states remained in place for a while. In the reunified Germany, Saxony was one of the last federal states in mid-2015 to implement the changeover.
Numerous map series published in the former Eastern Bloc are also based on the Krassowski ellipsoid, including the world map 1: 2.5 million .
literature
- Karl Ledersteger : Astronomical and Physical Geodesy . Volume V of the Jordan-Eggert- Kneissl series of books , Handbook of Surveying ; 871 pp., Verlag JB Metzler, Stuttgart 1969.
Individual evidence
- ↑ New official situation reference system ETRS89_UTM33 (change since July 2015) , Staatsbetrieb Geobasisinformation und Vermessung Sachsen