FFT swept filtering: a bias-free method for processing fringe signals in absolute gravimeters

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00177016%3A_____%2F18%3AN0000004" target="_blank" >RIV/00177016:_____/18:N0000004 - isvavai.cz</a>

Alternative codes found

RIV/00025615:_____/19:N0000002

Result on the web

<a href="http://dx.doi.org/10.1007/s00190-018-1154-y" target="_blank" >http://dx.doi.org/10.1007/s00190-018-1154-y</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00190-018-1154-y" target="_blank" >10.1007/s00190-018-1154-y</a>

Result language

angličtina

Original language name

FFT swept filtering: a bias-free method for processing fringe signals in absolute gravimeters

Original language description

Absolute gravimeters, based on laser interferometry, are widely used for many applications in geoscience and metrology. Although currently the most accurate FG5 and FG5X gravimeters declare standard uncertainties at the level of 2−3μGal, their inherent systematic errors affect the gravity reference determined by international key comparisons based predominately on the use of FG5-type instruments. The measurement results for FG5-215 and FG5X-251 clearly showed that the measured g-values depend on the size of the fringe signal and that this effect might be approximated by a linear regression with a slope of up to 0.030 μGal/mV. However, these empirical results do not enable one to identify the source of the effect or to determine a reasonable reference fringe level for correcting g-values in an absolute sense. Therefore, both gravimeters were equipped with new measuring systems (according to Kˇren et al. in Metrologia 53:27–40, 2016. https://doi.org/10.1088/0026-1394/53/1/27 applied for FG5), running in parallel with the original systems. The new systems use an analogue-to-digital converter HS5 to digitize the fringe signal and a new method of fringe signal analysis based on FFT swept bandpass filtering. We demonstrate that the source of the fringe size effect is connected to a distortion of the fringe signal due to the electronic components used in the FG5(X) gravimeters. To obtain a bias-free g-value, the FFT swept method should be applied for the determination of zero-crossings. A comparison of g-values obtained from the new and the original systems clearly shows that the original system might be biased by approximately 3−5μGal due to improperly distorted fringe signal processing.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

<a href="/en/project/GA16-14105S" target="_blank" >GA16-14105S: Advanced processing of absolute gravity measurements and investigation of systematic instrumental effects</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Geodesy

ISSN

0949-7714

e-ISSN

—

Volume of the periodical

—

Issue of the periodical within the volume

2018

Country of publishing house

DE - GERMANY

Number of pages

9

Pages from-to

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UT code for WoS article

000459191400006

EID of the result in the Scopus database

2-s2.0-85047136123