Multi-scale feature tracking in sequential satellite images with wavelet analysis to measure sea surface currents in the Gulf of St. Lawrence
Bibliographic record
Abstract
AbstractMeasuring sea surface currents is a technological challenge in oceanography. Feature tracking in time series of remote sensing imagery has been proposed as a way to address this problem. The most commonly used approach is the maximum cross-correlation (MCC) method, originally developed to track cloud motion. We propose a new technique that makes use of Daubechies wavelet analysis combined with the MCC method. In our approach, satellite images are decomposed into various spatial scales using the wavelet transform, and the location with the MCC coefficient among all the scales is selected as the most likely new position of the tracked feature. Results from the analysis of five pairs of sequential National Oceanic and Atmospheric Administration (NOAA) advanced very high resolution radiometer (AVHRR) images of the Gulf of St. Lawrence area show that wavelet analysis improves the estimated sea surface current field by increasing the number of current vectors about 20% under the same confidence level (0.9) as compared with that using the MCC method alone.La mesure des courants océaniques de surface représente un défi technologique en océanographie. Le suivi de traceurs utilisant les séries chronologiques d'images de télédétection a été proposé comme solution à cette problématique. L'approche la plus utilisée est la méthode du maximum de corrélation croisée (MCC; « maximum cross-correlation ») développée au départ pour le suivi du mouvement des nuages. Nous proposons une nouvelle technique utilisant l'analyse par ondelettes Daubechies combinée à la méthode MCC. Dans notre approche, les images satellites sont décomposées en diverses échelles spatiales à l'aide de la transformée en ondelettes et la position affichant le coefficient de corrélation croisée maximum parmi toutes les échelles est choisie en tant que nouvelle position la plus plausible du traceur. Les résultats de l'analyse de cinq paires d'images séquentielles AVHRR (« advanced very high resolution radiometer ») de NOAA (« National Oceanic and Atmospheric Administration ») du golfe du Saint-Laurent montrent que l'analyse en ondelettes améliore l'estimation du champ de courant océanique de surface en augmentant le nombre de vecteurs de courant d'environ 20 %, avec le même niveau de confiance (0,9) par rapport à la méthode MCC seule.[Traduit par la Rédaction]
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How this classification was reachedexpand
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".