Talk:Bessel ellipsoid

Latest comment: 3 years ago by Mwtoews in topic EPSG:7004

Where is the source

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This page contains this statement: "The Bessel ellipsoid fits especially well to the geoid curvature of Europe and Eurasia." Where can I find source for this statement? Is there any comparison between Bessel and other ellipsoids (IUGG, WGS etc.)? Péter 11:36, 15 November 2008 (UTC)Reply

EPSG:7004

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There are currently a few issues with this article that are highlighted by EPSG:7004

  • The "Bessel 1841" ellipsoid is defined to be exactly a = 6377397.155 m, 1/f = 299.1528128. The current articles does not state these numbers, but shows unsourced values.
  • OGP's remarks are revealing:

    Original Bessel definition is a=3272077.14 and b=3261139.33 toise. This used a weighted mean of values from several authors but did not account for differences in the length of the various toise: the "Bessel toise" is therefore of uncertain length.

    • The secondary reference for this US Army Map Service Technical Manual; 1943. I can't easily find this source, but this would be a good reference to have.
    • The primary source is Bessel, F. W. (1841). "Ueber einen Fehler in der Berechnung der französischen Gradmessung und seinen Einfluß auf die Bestimmung der Figur der Erde" [Concerning an error in the calculation of the French survey and its influence on the determination of the figure of the Earth]. Astronomische Nachrichten (in German). 19 (438): 97–116. Bibcode:1841AN.....19...97B. doi:10.1002/asna.18420190702.. Look at the last page for a and b. It also has log a and log b values too.

If anyone has time to integrate this information into the article, please do. If not, then I'll get to this when time permits (it never does). +mt 00:44, 13 May 2021 (UTC)Reply