Precise Gravimetric Surveys with the Field Absolute Gravimeter A-10

Falk, Reinhard; Müller, Ja.; Lux, N.; Wilmes, H.; Wziontek, Hartmut

doi:10.1007/978-3-642-20338-1_33

Cited by 14 publications

(8 citation statements)

References 5 publications

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“…This approach can be understood as if the measurements of a particular gravimeter carried out within a few days are affected by a group of systematic errors that remain the same. For a few other types of instruments as A-10, CAG-01, a similar ratio between repeatability and declared uncertainty has been published (Falk et al 2012;Karcher et al 2018); therefore, we decided to apply the approach described for FG5/X for all other type of gravimeters, except the rise and fall type of gravimeter IMGC-02 (D'Agostino et al 2008), where random errors are dominating in the error budget (A. Prato, personal communication), and covariances have been set to zero.…”

Section: Construction Of the Input Covariance/weight Matrixmentioning

confidence: 88%

Evaluation of comparisons of absolute gravimeters using correlated quantities: reprocessing and analyses of recent comparisons

Pálinkáš

Wziontek

Vaľko

et al. 2021

J Geod

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Due to the lack of a natural reference for the absolute acceleration of free fall and gravity, absolute gravimeters are compared at international comparisons, where the gravity reference is realized based on a set of precise absolute measurements and the functional model for their processing. The main estimates of comparisons, specifically, the reference values, deviations of gravimeters (biases) and associated uncertainty estimates, are obtained by the method of constrained least squares. In this paper, based on data from six comparisons, we demonstrate and discuss the importance of several aspects that significantly influence the estimated parameters, such as the type of the constraint, the weighting schemes, the correlations between measurements or outlier detection. Following the state-of-the-art key comparisons in metrology, we are applying correlations between measurements of a particular gravimeter for the first time, showing the ability to obtain appropriate uncertainty estimates, strictly applying the law of error propagation. The processing of comparisons by the method of least squares is described step by step to provide a background for analyses of absolute gravimeter comparisons in the future, reflecting all specifics of these comparisons. Estimated parameters from uniformly elaborated comparisons represent an interesting statistical data set that has been used to analyse the significance of differences between FG5, FG5X and other types of gravimeters. We believe that the described method of processing, as well as the published results, will be especially useful in the realization of the International Gravity Reference System.

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Section: Construction Of the Input Covariance/weight Matrixmentioning

confidence: 88%

Evaluation of comparisons of absolute gravimeters using correlated quantities: reprocessing and analyses of recent comparisons

Pálinkáš

Wziontek

Vaľko

et al. 2021

J Geod

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“…Compatible infrastructure (markers, points) and documentation (database) used today. Field versions (e.g., A10 by Micro-g LaCoste) allow surveys with an accuracy of 5-10 µGal (Falk et al 2012), and the rapid development of quantum gravimeters (Gillot et al 2016;Freier et al 2016) opens up new perspectives and has brought with the Absolute Quantum Gravimeter (AQG) a first model on the market (Ménoret et al 2018). Such instrumentation guaranteeing a relative accuracy of 10 −8 and better has been demonstrated to be relevant in metrology for the realization of the definition of the kilogram with the Kibble balance (Robinson 2011;Robinson and Schlamminger 2016) and in geosciences to study geodynamics, hydrology and global change in the Earth system (Van Camp et al 2017).…”

Section: Reference Systemmentioning

confidence: 99%

Status of the International Gravity Reference System and Frame

Wziontek

Bonvalot

Falk

et al. 2021

J Geod

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The increasing importance of terrestrial gravimetry in monitoring global change processes, in providing a reference for satellite measurements and in applications in metrology necessitates a stable reference system reflecting the measurement accuracy achievable by modern gravimeters. Therefore, over the last decade, the International Association of Geodesy (IAG) has developed a system to achieve accurate, homogeneous, long-term global recording of Earth’s gravity, while taking advantage of the potential of today’s absolute gravity measurements. The current status of the International Gravity Reference System and Frame is presented as worked out by the IAG Joint Working Group 2.1.1 “Establishment of a global absolute gravity reference system” during the period 2015–2019. Here, the system is defined by the instantaneous acceleration of free-fall, expressed in the International System of Units (SI) and a set of conventional corrections for the time-independent components of gravity effects. The frame as the systems realization includes a set of conventional temporal gravity corrections which represent a uniform set of minimum requirements. Measurements with absolute gravimeters, the traceability of which is ensured by comparisons and monitoring at reference stations, provide the basis of the frame. A global set of such stations providing absolute gravity values at the microgal level is the backbone of the frame. Core stations with at least one available space geodetic technique will provide a link to the terrestrial reference frame. Expanded facilities enabling instrumental verification as well as repeated regional and additional comparisons will complement key comparisons at the level of the International Committee for Weights and Measures (CIPM) and ensure a common reference and the traceability to the SI. To make the gravity reference system accessible to any user and to replace the previous IGSN71 network, an infrastructure based on absolute gravity observations needs to be built up. This requires the support of national agencies, which are encouraged to establish compatible first order gravity networks and to provide information about existing absolute gravity observations.

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“…Both the A10 [5,18] and the FG5 [21] are free-fall gravimeters with similar working principles, i.e. they allow gravity to be estimated from time-distance pairs describing the trajectory of a free-falling test mass inside a vacuum chamber.…”

Section: Analysis Of Gravity Observationsmentioning

confidence: 99%

“…Unfortunately, the A10's robustness is at cost of accuracy. It has an accuracy of better than 10 µGal (1 µGal = 10 −8 m/s 2 ) at field sites, assuming that instrument standards are checked [5]. In contrast, the FG5 provides measurements with an accuracy of typically 1-2 µGal and allows gravity changes to be estimated with a precision of 0.5 µGal/yr after 10 years of annual measurements [35].…”

Section: Analysis Of Gravity Observationsmentioning

confidence: 99%

Research Article. A new gravity laboratory in Ny-Ålesund, Svalbard

Breili

Hougen

Lysaker

et al. 2017

Journal of Geodetic Science

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Abstract:The Norwegian Mapping Authority (NMA) has recently established a new gravity laboratory in Ny-Ålesund at Svalbard, Norway. The laboratory consists of three independent pillars and is part of the geodetic core station that is presently under construction at Brandal, approximately 1.5 km north of NMA's old station. In anticipation of future use of the new gravity laboratory, we present benchmark gravity values, gravity gradients, and final coordinates of all new pillars. Test measurements indicate a higher noise level at Brandal compared to the old station. The increased noise level is attributed to higher sensitivity to wind. We have also investigated possible consequences of moving to Brandal when it comes to the gravitational signal of present-day ice mass changes and ocean tide loading. Plausible models representing ice mass changes at the Svalbard archipelago indicate that the gravitational signal at Brandal may differ from that at the old site with a size detectable with modern gravimeters. Users of gravity data from Ny-Ålesund should, therefore, be cautious if future observations from the new observatory are used to extend the existing gravity record. Due to its lower elevation, Brandal is significantly less sensitive to gravitational ocean tide loading. In the future, Brandal will be the prime site for gravimetry in Ny-Ålesund. This ensures gravity measurements collocated with space geodetic techniques like VLBI, SLR, and GNSS.

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Precise Gravimetric Surveys with the Field Absolute Gravimeter A-10

Cited by 14 publications

References 5 publications

Evaluation of comparisons of absolute gravimeters using correlated quantities: reprocessing and analyses of recent comparisons

Evaluation of comparisons of absolute gravimeters using correlated quantities: reprocessing and analyses of recent comparisons

Status of the International Gravity Reference System and Frame

Research Article. A new gravity laboratory in Ny-Ålesund, Svalbard

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