Geoid investigations for the new vertical datum in Canada
Why this work is in the frame
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Bibliographic record
Abstract
The aim of this study is to investigate the current vertical datums in North America and to assess the possible improvements to them coming from the recently obtained satellite gravity models.The study is conducted in two steps.First, the geoid models computed from the first and the second generation GOCE-only and GRACE-GOCE combined satellite-only models and truncated for different spherical harmonic degrees are compared to the GPS/leveling geoid heights which are reduced to the same spectral band of the gravity field.The GPS/leveling-derived geoid heights are used as independent controls in the assessment of the geoid models.The comparison results indicate that the GOCE models show a full power of gravity signal in terms of geoid undulation up to about spherical harmonic degree 150.Second, one of the first generation GOCE satellite-only models developed by the time-wise approach, TW01, is complemented with local terrestrial data and tested against the GPS/leveling-derived geoid undulations in full spectrum of the gravity field and compared with the official global and regional geoid models.Based on these results there is not enough evidence indicating significant improvement (cm level) from the first generation GOCE models to the geoid modeling in Canada and the two sub-regions, the Great Lakes area and Rocky Mountains investigated, compared to EGM2008 and the existing regional geoid models.One important contribution is the evaluation of the GOCE-only and complementary terrestrial data combined geoid model in Canada without any effect of the other satellite and geodetic techniques.The preliminary investigations on the second generation GOCE models show that the future GOCE-only and combined GRACE-GOCE models can provide more accurate and consistent geoid solutions for Canada.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.011 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.004 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
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 it