On the effective position of the free-fall solution and the self-attraction effect of the FG5 gravimeters
Bibliographic record
Abstract
FG5 absolute gravimeters are the most accurate gravimeters available at present and have significant influence on the realization of a gravity reference through international comparisons of absolute gravimeters. The latter comparisons are the only way to maintain the traceability of absolute gravimetry to the International System of Units (SI). Sources of systematic error such as the self-attraction effect (SAE) have to be taken into account when determining accurate values of the acceleration due to gravity, as needed, for example, for the watt balance project or the International Gravity Reference System. In this paper the SAE for two types of FG5 gravimeter is estimated using two independent methods. The resulting SAEs are 1.2(0.2) µGal and 1.7(0.2) µGal for FG5 with fibre and bulk interferometer types, respectively. The importance of accurately defining the measurement height is emphasized in the context of the SAE. The accuracy and advantages of referring gravity measurements to an effective position of the free-fall solution are demonstrated together with a simple and accurate empirical estimation of this effective position.
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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 | 0.003 | 0.007 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".