000002924 001__ 2924
000002924 005__ 20160915115813.0
000002924 037__ $$aCTALK-2016-0005
000002924 100__ $$aVan Camp, M.
000002924 245__ $$aOptimized strategy for the calibration of superconducting gravimeters at the one per mille level
000002924 260__ $$c2016
000002924 269__ $$c2016-02-23
000002924 520__ $$aThis reports on different sources of errors that occur in the calibration process of a superconducting gravimeter (SG), determined by comparison with a ballistic absolute gravimeter (AG); some of them have never been discussed in the literature.We then provide methods to mitigate the impact of those errors, to achieve a robust calibration estimate at the 1 0/00 level. We demonstrate that a standard deviation at the level of 1 0/00 can be reached within 48 h by measuring at spring tides and by increasing the AG sampling rate. This is much shorter than what is classically reported in previous empirical studies. Measuring more than 5 days around a tidal extreme does not improve the precision in the calibration factor significantly, as the variation in the error as a function of 1/√N does not apply, considering the decrease in signal amplitude due to the tidal modulation. However, we investigate the precision improvement up to 120 days, which can be useful if an AG is run continuously: at mid-latitude it would require 21 days to ensure a calibration factor at the 1 0/00 level with a 99.7 % confidence interval. We also show that restricting the AG measurement periods to tidal extrema can reduce instrument demand, while this does not affect the precision on the calibration factor significantly. Then, we quantify the effect of high microseismic noise causing aliasing in the AG time series. We eventually discuss the attenuation bias that might be induced by noisy time series of the SG. When experiments are performed at the 1 0/00 level,7 are needed to ensure that the error in the calibration estimate will be at the 1 per mille level with a 99 % confidence.
000002924 594__ $$aNO
000002924 700__ $$ade Viron, O.
000002924 700__ $$aMeurers, B.
000002924 700__ $$aForbriger, T.
000002924 773__ $$tCCM-WGG (consultative Committee for Mass and Related Quantities Working Group on Gravimetry) meeting, Brussels, 23-24 Feb 2016
000002924 8560_ $$fmichel.vancamp@observatoire.be
000002924 906__ $$aContributed
000002924 980__ $$aCTALKCONT