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Optimized strategy for the calibration of superconducting gravimeters at the one per mille level / Michel Van Camp in Journal of geodesy, vol 90 n° 1 (January 2016)  

Public [article]  inJournal of geodesy > vol 90 n° 1 (January 2016) . - pp 91- 99 Titre : Optimized strategy for the calibration of superconducting gravimeters at the one per mille level Type de document : Article/Communication Auteurs : Michel Van Camp, Auteur ; Bruno Meurers, Auteur ; Olivier de Viron, Auteur ; Thomas Forbriger, Auteur Année de publication : 2016 Article en page(s) : pp 91- 99 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] étalonnage d'instrument [Termes IGN] gravimètre absolu [Termes IGN] gravimètre supraconducteur [Termes IGN] marée terrestre Résumé : (auteur) This paper 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 http://static-content.springer.com/image/art%3A10.1007%2Fs00190-015-0856-7/MediaObjects/190_2015_856_IEq1_HTML.gif level. We demonstrate that a standard deviation at the level of http://static-content.springer.com/image/art%3A10.1007%2Fs00190-015-0856-7/MediaObjects/190_2015_856_IEq2_HTML.gif 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 http://static-content.springer.com/image/art%3A10.1007%2Fs00190-015-0856-7/MediaObjects/190_2015_856_IEq4_HTML.gif 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 http://static-content.springer.com/image/art%3A10.1007%2Fs00190-015-0856-7/MediaObjects/190_2015_856_IEq5_HTML.gif 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. Numéro de notice : A2016-021 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0856-7 Date de publication en ligne : 25/09/2015 En ligne : https://doi.org/10.1007/s00190-015-0856-7 Format de la ressource électronique : Url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79469 [article]