Revisiting absolute gravimeter intercomparisons

O de Viron (1) , M van Camp (2) , O Francis (3)

1 IPGP - Institut de Physique du Globe de Paris
2 ROB - Royal Observatory of Belgium = Observatoire Royal de Belgique
3 FSTC - Faculty of Science, Technology and Communication [Luxembourg]

Absolute gravimeter allows to determine the local value of gravity, which makes challenging its accuracy assessment. The instrumental offsets are classically estimated by performing comparisons of the results obtained by a set of instruments measuring at the same location but at different epochs (measuring at the same place and epoch is physically impossible). Such intercomparison campaigns have been done a few times since 1980. In this paper, we discuss the method of data processing used for those comparisons. We demonstrate that one of the methods used is inadequate, as it underestimates the dispersion of the instrumental offsets, which is the only reliable quantity that can be obtained from such a comparison. We also propose a new criterion, based on the minimization of the L1 norm of the offsets, for fixing the constant of the ill-conditioned problem, which we show to be statistically more precise than the one classically used.

Domaines: Géophysique [physics.geo-ph]

O de Viron, M van Camp, O Francis. Revisiting absolute gravimeter intercomparisons. Metrologia, 2011, 48, pp.290 - 298. ⟨10.1088/0026-1394/48/5/008⟩. ⟨hal-01087247⟩