Results of the Sixth International Comparison of Absolute Gravimeters, ICAG-2001

The Sixth International Comparison of Absolute Gravimeters was held from 2 July to 28 August 2001 at the Bureau International des Poids et Mesures (BIPM), Sèvres. Seventeen absolute gravimeters were used to make measurements at five sites of the BIPM gravity network. The vertical gravity gradients at the sites and the ties between them were also measured using seventeen relative gravimeters. For the first time the ties were also measured using the absolute gravimeters. Various methods of processing the absolute and relative data were tested to calculate the results. The final results of the ICAG-2001 are presented. The acceleration due to gravity at a height of 0.90 m is given as (980 925 701.2 ± 5.5) µGal and (980 928 018.8 ± 5.5) µGal for sites A and B, respectively, calculated using a combined adjustment of the absolute and relative data.