Great Theodolite
The Bache- Wurdemann Compensating Device
Eimbeck Duplex Bars
Iced Bar B 17
Steel Tape with Tape Stretcher
Invar Tape
AGA Geodimeter NASM-2A
Tellurometer Model M/RA 1
Laser Signal and Prismatic Mirror Reflecting System
AGA Geodimeters, Models 4D and 4L
Big Red
AGA Geodimeter Model 6
Hewlett-Packard Model 3800B Distance Meter
Tellurometer Model MA-100
Ranger III and Rangemaster III
Topcon ET-1 Total Station
Trimble GPS Antenna
Ranger III and Rangemaster III
Released in 1970, the Ranger series of electronic distance measurement instruments used lasers to measure distances. Easier to use than earlier electronic distance measurement instruments, these instruments were completely automatic, fast, and featured an electronic read-out panel. These instruments were used by the National Geodetic Survey throughout the 1970s.
Ranger systems (top) and Rangemaster (bottom). Photos courtesy of Charlie Glover.
The first automatic electro-optical distance measuring instrument to be made available to the general public was a Ranger. This first Ranger was designed by John Shipp partly as a challenge to the AGA Corporation of Sweden: up until about 1969, the only survey-grade instrument of this type was the AGA's Geodimeter. Unveiled at an American Congress of Surveying and Mapping convention in Washington, DC, the Ranger sent a red laser to a reflector mounted on the wall about 50 feet (15.2 meters) away. The Ranger's "MEASURE" button was a proximity switch that did not move when touched, working instead from the added electrical energy generated by the contact of a finger to the button. This touch triggered a measuring sequence that resulted in the appearance of the distance on an light-emitting diode (LED) display within seconds.
Shipp established Laser Systems & Electronics, Inc. (LSE), selling the electronic distance measurement instruments branch to Keuffel & Esser in 1971, who then produced the Rangemaster series. The Ranger and Rangemasters were used by the National Geodetic Survey for mark maintenance and special projects work in the 1970s. Shipp himself went on to design a heart monitor that transmitted the results over a phone line.
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Distance Measurement Instrument Shown: Ranger III and Rangemaster III - Location: Corbin, Virginia
- Manufacture Date: 1970
- Dates of Use: 1970s
- Photo Date: 2006
Works Consulted
Burger, T. C., Tomlinson, R. W. (1975). Electronic Distance Measuring Instruments. Washington, DC: American Congress on Surveying and Mapping.
Smithsonian Virtual Surveying Instrument Collection. EDM (Ranger). Retrieved June, 2006, from:
http://americanhistory.si.edu/collections/surveying/object.cfm?recordnumber=748794.
Smithsonian Virtual Surveying Instrument Collection. Laser Systems & Electronics. Retrieved June 2006, from: http://americanhistory2.si.edu/collections/surveying/maker.cfm?makerid=45.