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Results of the first North American comparison of absolute gravimeters, NACAG-2010

January 1, 2012

The first North American Comparison of absolute gravimeters (NACAG-2010) was hosted by the National Oceanic and Atmospheric Administration at its newly renovated Table Mountain Geophysical Observatory (TMGO) north of Boulder, Colorado, in October 2010. NACAG-2010 and the renovation of TMGO are part of NGS’s GRAV-D project (Gravity for the Redefinition of the American Vertical Datum). Nine absolute gravimeters from three countries participated in the comparison. Before the comparison, the gravimeter operators agreed to a protocol describing the strategy to measure, calculate, and present the results. Nine sites were used to measure the free-fall acceleration of g. Each gravimeter measured the value of g at a subset of three of the sites, for a total set of 27 g-values for the comparison. The absolute gravimeters agree with one another with a standard deviation of 1.6 µGal (1 Gal = 1 cm s-2). The minimum and maximum offsets are -2.8 and 2.7 µGal. This is an excellent agreement and can be attributed to multiple factors, including gravimeters that were in good working order, good operators, a quiet observatory, and a short duration time for the experiment. These results can be used to standardize gravity surveys internationally.

Publication Year 2012
Title Results of the first North American comparison of absolute gravimeters, NACAG-2010
DOI 10.1007/s00190-011-0539-y
Authors David Schmerge, Olvier Francis, J. Henton, D. Ingles, D. Jones, Jeffrey R. Kennedy, K. Krauterbluth, J. Liard, D. Newell, R. Sands, J. Schiel, J. Silliker, D. van Westrum
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Geodesy
Index ID 70045211
Record Source USGS Publications Warehouse
USGS Organization Arizona Water Science Center