CCM.G-K2.2023: CIPM key comparison of absolute gravimeters
Bibliographic record
Abstract
Main text The Key Comparison of Absolute Gravimeters, CCM.G-K2.2023, was conducted at the Table Mountain Geophysical Observatory (TMGO) near Boulder, Colorado between 21 August and 29 September, 2023. Dr David Newell of the National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, served as the Pilot Laboratory representative, while Dr Derek van Westrum of the National Oceanic and Atmospheric Administration National Geodetic Survey (NOAA-NGS), Boulder, Colorado, served as the site host and coordinator. The comparison was organized in accordance with the International Committee for Weights and Measures (CIPM) document CIPM MRA-G-11 of the Consultative Committee for Mass and Related Quantities (CCM) and is registered with the CIPM as CCM.G-K2.2023. Fifteen National Metrology Institutes (NMIs) or Designated Institutes (DIs) participated, with a total of 30 absolute gravimeters from 27 institutes, including 2 atom gravimeters. Since all the contributions of absolute gravity data were consistent within the 95% confidence level of applied consistency tests, no data were omitted in the final analysis. The standard deviation of the gravimeters' degrees of equivalence (DoEs) for CCM.G-K2.2023 is less than 1.3 µGal, indicating excellent agreement among the gravimeters. In this report, the gal (symbol: Gal) is a non-SI unit of acceleration employed in geodesy and geophysics to express acceleration due to gravity, where 1 Gal = 1 cm s-2 (1 µGal = 10-8 m s-2). To reach the main text of this paper, click on Final Report . Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/ . The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.012 | 0.028 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.005 | 0.007 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.004 | 0.003 |
| Open science | 0.006 | 0.003 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.125 | 0.078 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".