Soldner coordinate system

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Soldner coordinate systems in the German states around 1900

The Soldner coordinate system is a Cartesian coordinate system that goes back to the astronomer, geodesist , mathematician and physicist Johann Georg von Soldner .

The map network design of this coordinate system is an equidistant cylindrical image in a transverse position. Here is the meridian ( central meridian ), which should be at the center of the survey area, length faithfully displayed. On the map, it represents the vertical X-axis ( abscissa ), which is positive towards north. The positive legal values are at right angles thereto (d. E. Horizontally) measured in the direction East, and also shown true length. Since the high values in the mapping of the earth's ellipsoid on the cylinder are distorted the further one moves away from the central meridian, the areas shown are limited to 64 km on both sides of the main meridian.

So that no negative coordinates arise, these have been enlarged by 100 km (decadic additions, marked with x), or the coordinate origin is fictitiously relocated to a point southwest of the mapping area by using additional coordinates.

The limitation in width led to a large number of local coordinate systems for which different reference surfaces were also intended (e.g. Bavaria: sphere, Prussia: Bessel ellipsoid ). Soldner coordinates were used in large parts of Germany well into the 20th century, but then largely replaced by the Gauß-Krüger coordinate system and today the ETRS 89 reference system from the 1920s .

In the state of Berlin , due to its location in the transition between Gauß-Krüger zones 4 and 5 (central meridians 12 ° and 15 ° east longitude) , the 18th Soldner coordinate system of the Prussian cadastral survey , established in 1879, was used for the real estate cadastre until July 20, 2015 , which has its origin in the first order trigonometric point Müggelberg .

Further examples for the choice of the origin of Soldner coordinate systems are:

literature

  • Günter Hake : Cartography. Volume 1: Map recording, network designs, design features, topographical maps (= Göschen Collection 9030). 5th revised edition. de Gruyter, Berlin et al. 1975, ISBN 3-11-005769-7 .
  • Hans-Gerd Becker: Müggelberg Soldner System - A Surveying Monument? in On the trail of land surveying in Berlin and Brandenburg , 2014, Potsdam, p. 22

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