PRETTY - ESA's GNSS Reflection Technology for Remote Sensing of the Earth
Notice bibliographique
Résumé
PRETTY (Passive REflecTometry and dosiomeTrY) is a small satellite project of the European Space Agency (ESA). The PRETTY CubeSat is a nanosatellite, measuring 30 cm by 10 cm by 10 cm in the launch configuration. On 9 October 2023, the satellites was launched into a sun-synchronous polar Low Earth Orbit (LEO) with an inclination of (97.66)°, a low orbit eccentricity and a mean orbit height of 564 km. PRETTY includes a demonstrator payload for passive Global Navigation Satellite Systems (GNSS) based Reflectometry (GNSS-R) focusing on low elevation angles whereby the direct and reflected signal are received via the same antenna. PRETTY also includes a novel dosimeter to measure the Total Ionizing Dose (TID). The main scientific goal of the mission is the precise altimetric determination of water and ice surfaces. High-precision results are expected with a phase altimetric approach. However, phase altimetry using reflected GNSS signals requires coherent reflection conditions that are dependent on surface roughness conditions and usually limited to smooth surface over calm ocean, sea-ice, and inland water bodies. A second approach will use group delay measurements to investigate the altimetric application under higher ocean roughness conditions. Possibility of making use of PRETTY's scatterometry data to study wind, ocean and soil moistures will also be investigated as the secondary scientific goal. Three levels of data are produced within the data recording and processing steps of the PRETTY. The lowest level of data, i.e., Level 0 includes the correlation sums at In-phase and Quadrature (I/Q) channels produced by the PRETTY onboard processor. Level 1 data includes the complex delay waveforms and power Delay-Doppler Maps (DDM) accompanied by different pieces of ancillary information and metadata. The scientific data products of PRETTY, i.e., altimetric and scatterometric measurements, are being tested now, and they will be provided as Level 2 data. The Level 1 and Level 2 data products are released in the form of NetCDF files. On 15 February 2024, we witnessed PRETTY's first light over a lonely polar island in the Canadian Arctic. Quality of the result was very good as this was basically the first time the PRETTY's software was turned on since reaching orbit. More data are gathered since February and testing and cross-checking of results are performed. The initial data sets, tracks, the signal strength as a function of coherent integration, the recording of the carrier phase, and the level 2 altimetric products will be presented.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,014 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».