page_title: Transcontinental Traverse
section_title: Equipment and methods
hierarchical_section_title: Transcontinental Traverse / Equipment and methods
caption_attribution_description: English: Two complete Bilby Towers on Transcontinental Geodimieter Traverse. (original image caption)
context_page_description: The Transcontinental Traverse was a geodetic survey traverse conducted in the Continental United States by the U.S. Coast and Geodetic Survey between 1961 and 1976. It was the most accurate large-area survey ever done prior to Global Positioning System surveys. TCT included over 2,700 survey stations, covered over 13,600 miles, and passed through 44 states.
  This nationwide survey increased the accuracy of the existing U.S. survey network. It was also fundamental to the sophisticated mathematical readjustment of the nation's survey network known as the North American Datum of 1983. It was the "end of an era" as the last conventional, purely terrestrial large scale survey.
context_section_description: The traverse made use of the geodimeter, a lightwave phase electronic distance measurement instrument that had just been invented when the traverse began. The instruments were located atop Bilby towers many meters above ground level to avoid obscuring objects and to get a smoother air temperature profile for accuracy. Due to the light source then in use, the geodimeter could only be operated at night.
caption: Two complete Bilby towers on Transcontinental Traverse
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