Atmospheric Effects in Geodetic Levelling

Abstract

The knowledge of physical processes and changes in the atmosphere is essential when addressing the fundamental problem, i.e. the accuracy of geodetic measurements. In levelling operations, all these changes are explained as the effect of refraction, which systematically distorts the results of levelling. Different ways of addressing the effect of refraction are represented based on the modelling of the vertical temperature gradient as the quantity that has the most influence on the refraction phenomenon.

On the Use of Repeat Leveling for the Determination of Vertical Land Motion: Artifacts, Aliasing, and Extrapolation Errors

“…Atmospheric refraction is considered the most complex source of systematic error affecting leveling observations (e.g., Angus-Leppan, 1979;Breznikar & Aksamitauskas, 2012;Holdahl, 1981;Kukkamäki, 1938Kukkamäki, , 1939Shaw & Smietana, 1983;Skeivalas, 2005;Stein et al, 1986;Strange, 1981). The variability of atmospheric conditions within and between each epoch of a repeat leveling campaign has the potential to introduce artifacts into the resulting time series.…”