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Removal of refraction errors in geodetic leveling

Published online by Cambridge University Press:  14 August 2015

Sandford R. Holdahl*
Affiliation:
National Geodetic Survey National Ocean Survey/NOAA Rockville, Maryland 20782

Extract

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Refraction error is often regarded as the most serious problem with geodetic leveling. Its accumulation depends on the slope of the terrain being leveled, length of sight, and the vertical temperature gradient. Refraction error can be minimized by limiting and balancing sight lengths, and by not reading the portion of the level rod which is within 0.5 meter of the ground where air density changes most rapidly. The remaining refraction error should be removed by application of a correction to leveling data, otherwise heights and crustal motion may be determined so weakly that meaningful conclusions or interpretations cannot be inferred from the data by geophysicists.

Type
Research Article
Copyright
Copyright © Reidel 1979 

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