The Geodimeter (acronym of geodetic distance meter) was the first optical electronic distance meter surveying instrument.[1][2] It was originally developed for measuring the speed of light.[3][4] It was invented in 1947 by Erik Osten Bergstrand [sv] and commercialized in 1953 by the AGA (Aktiebolaget Gasaccumulator) company of Sweden.[5][6] It was used in the Transcontinental Traverse.

Operator controls and sight of a Geodimeter

Electronic mechanismEdit

The mechanism uses a Kerr cell in an optical train that chops a collimated light beam under the control of a precision electronic oscillator in the megahertz range.[7] It is similar in principle to earlier mechanical choppers in Fizeau–Foucault apparatus that used a toothed wheel or a rotating mirror.[8]

See alsoEdit


  1. ^ Rüeger 2012, p. 15.
  2. ^ Bergstrand 1952.
  3. ^ Froome & Essen 1969.
  4. ^ Bergstrand 1950.
  5. ^ Laurila 1960, p. 194.
  6. ^ "AGA Geodimeter". AGA Museum. 2014-10-03. Retrieved 2020-09-24.
  7. ^ Poling 1959.
  8. ^ "EDM (Geodimeter Model 2A)", Database: Physical Sciences Collection - Surveying and Geodesy, Smithsonian Institution, catalog number 1998.3094.01, retrieved 2018-05-02


Further readingEdit

External linksEdit