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Record W2793956763 · doi:10.4095/286332

Application of GPS heights to Bay of Fundy multibeam data

2010· report· en· W2793956763 on OpenAlexaboutno aff
David Dodd

Bibliographic record

Venuenot available
Typereport
Languageen
FieldEarth and Planetary Sciences
TopicGeophysics and Gravity Measurements
Canadian institutionsnot available
Fundersnot available
KeywordsBayGlobal Positioning SystemGeodesyGeologyOceanographyRemote sensingTelecommunicationsComputer science

Abstract

fetched live from OpenAlex

Between 1996 and 2009 several different vessels conducted mutibeam surveys in the Bay of Fundy. Removal of the tidal effect and the establishment of a vertical reference were the most challenging aspects of the data reduction process. Due to the tidal range (8 to 16 metres) these effects must be removed in order for the results to be used effectively. Simply establishing gauges and measuring tides is extremely challenging, which makes this environment ideal for the use of GPS heights. Surveys conducted in 2007, 2008 and 2009 observed GPS heights during multibeam data collection. Surveys conducted prior to 2007 relied on a combination of tide gauge observations and predicted tides. The mandate for this project was to reduce the 2007 to 2009 surveys to a common Mean Sea Level (MSL) datum, and to try to incorporate surveys conducted prior to 2007. GPS heights from multibeam surveys conducted by the Creed, Matthew, Plover and Pipit in 2007, 2008 and 2009 were used to remove tidal effects and establish the vertical datum. GPS height observations were evaluated with respect to the Saint John tide gauge. GPS Tides were edited to remove sections where high-accuracy GPS solution was not available. Depths were determined relative to the International Terrestrial Reference Frame (ITRF), as established by the GPS observations. Lines where GPS heights were not available were removed from the process. Depths from each survey were used to create regular gridded surfaces at a 5X5 metre resolution. All surfaces were compared to ensure consistency in overlap areas and combined into a single surface. Three surveys conducted by the Creed prior to 2007 (without GPS heights) were included in the final surface. These included surveys conducted in 1996, 1999 and 2006. Initial tidal references were derived from predicted tides. Surfaces derived from these tidal datums were adjusted to the ITRF97 (1997 epoch) reference through a geoid-to-ellipsoid model (Canadian Spatial Reference System [CSRS] NT2). These surfaces were then compared to 2007-2009 surfaces where overlap occurred. Biases between the GPS derived ITRF surfaces and the MSL shifted surfaces ranged between 0.15 to 0.45 m. Sea Surface topography was not included in the shifting and will be included in the bias value. The standard deviation (1sigma) ranged between 0.6 and 1.6 metres. The high standard deviations can be attributed to the tidal model (Scotia Shelf) used to derive the predicted tides. Surveys conducted by the UNB OMG using the Heron were also incorporated into the final project.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.701
Threshold uncertainty score0.975

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.083
GPT teacher head0.292
Teacher spread0.208 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations6
Published2010
Admission routes1
Has abstractyes

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