Geodimeter
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 and commercialized in 1953 by the AGA (Aktiebolaget Gasaccumulator) company of Sweden.[5][6] It was used in the Transcontinental Traverse.
The Geodimeter business was acquired by SpectraPrecision which was acquired by Trimble Inc.[citation needed]
Electronic mechanism
[edit | edit source]The mechanism uses a Kerr cell in an optical train that chops a collimated beam of light under the control of a precision electronic oscillator in the megahertz range.[7] It is similar in principle to the mechanical chopper in Fizeau's measurement of the speed of light in air that used a toothed wheel.[8]
See also
[edit | edit source]References
[edit | edit source]- ^ Rüeger 2012, p. 15.
- ^ Bergstrand 1952.
- ^ Froome & Essen 1969.
- ^ Bergstrand 1950.
- ^ Laurila 1960, p. 194.
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- ^ Poling 1959.
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Sources
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Further reading
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External links
[edit | edit source]- AGA Geodimeter Model 6 (Going the Distance: A Photo Collection Illustrating the History of Distance Measurement Tools at the National Geodetic Survey)
