UNIVERSITY OF CALGARY Terrain Effects on Geoid Determination
Bibliographic record
Abstract
Gravimetric reduction schemes play an important role on precise geoid determination, especially in rugged areas. The main theme of this research is to explore different gravimetric reduction schemes in the context of precise geoid determination, in addition to the usual Helmert’s second method of condensation and residual terrain model (RTM). A numerical investigation is carried out in the rugged area of the Canadian Rockies to study gravimetric geoid solutions based on the Rudzki inversion scheme, Helmert’s second method of condensation, RTM, and the topographic-isostatic reduction methods of Airy-Heiskanen (AH) and Pratt-Hayford (PH). The mathematical formulations of each of these techniques are presented. This study shows that the Rudzki inversion scheme, which had neither been used in practice in the past nor is it used at present, can become a standard tool for gravimetric geoid determination since the Rudzki geoid performs as well as the Helmert and RTM geoids (in terms of standard deviation and range of maximum and minimum values) when compared to the GPS-levelling geoid of the test area. Also, it is the only gravimetric reduction scheme which does not change the equipotential surface
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.028 | 0.005 |
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".