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The Geodimeter (acronym of geodetic distance meter) was the first optical electronic distance meter
AGA Geodimeter Model 6
(''Going the Distance: A Photo Collection Illustrating the History of Distance Measurement Tools at the
The Geodimeter (acronym of geodetic distance meter) was the first optical electronic distance meter surveying instrument
Instruments used in surveying include:
* Alidade
* Alidade table
* Cosmolabe
* Dioptra
* Dumpy level
* Engineer's chain
* Geodimeter
* Graphometer
* Groma (surveying)
* Laser scanning
* Level
* Level staff
* Measuring tape
* Plane table
* ...
.
It was originally developed for measuring the speed of light.
It was invented in 1947 by and commercialized in 1953 by the AGA (''Aktiebolaget Gasaccumulator'') company of Sweden.
It was used in the Transcontinental Traverse.
The Geodimeter business was acquired by SpectraPrecision which was acquired by Trimble Inc
Trimble Inc. is an American software, hardware, and services technology company. Trimble also does hardware development of global navigation satellite system (GNSS) receivers, scanners, total stations, laser rangefinders, unmanned aerial vehicl ...
.
Electronic mechanism
The mechanism uses a Kerr cell in an optical train that chops a collimated beam of light under the control of a precisionelectronic oscillator
An electronic oscillator is an electronic circuit that produces a periodic, oscillating or alternating current (AC) signal, usually a sine wave, square wave or a triangle wave, powered by a direct current (DC) source. Oscillators are found ...
in the megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base ...
range. 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.
See also
*Laser rangefinder
A laser rangefinder, also known as a laser telemeter or laser distance meter, is a rangefinder that uses a laser beam to determine the distance to an object. The most common form of laser rangefinder operates on the time of flight principle by ...
*Lidar
Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...
* Tellurometer
References
Sources
* * * * * *Further reading
* * * *External links
AGA Geodimeter Model 6
(''Going the Distance: A Photo Collection Illustrating the History of Distance Measurement Tools at the
National Geodetic Survey
The National Geodetic Survey (NGS) is a List of federal agencies in the United States, United States federal agency based in Washington, D.C. that defines and manages a national geographic coordinate system, coordinate system, providing the fou ...
'')
20th-century inventions
Surveying instruments
Swedish inventions
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