A RADARSAT-2 polarimetric multi-incidence angle analysis over archaeological sites. The ancient UNESCO city of Samarra (Iraq)
Notice bibliographique
Résumé
The present is part of a PhD project carried out between the University of Rome “Sapienza” and the University of Rennes1. This work has as goal the detection of archaeological buried remains and the monitoring of the external ones. \nThe archaeological site taken into account for this purpose is the area of the ancient octagonal city funded by Harun al-Rashid: al-Qadisiyya. This city, located in the southern part of the Samarra territory (Longitudes 43°45’- 43°51’; Latitudes 34°25’-34°05’ for a total extension of 15058 hectares), was abandoned unfinished when the caliph moved to Raqqa (Syria) in 796 A.D. Bigness of the structures and extensive excavation not yet occurred in that zone (as for the remaining 80% of the whole archaeological zone – 45km x 6km extension), the unstable political situation and agricultural expansion threats (that let the city of Samarra be inscribed in the UNESO list of sites in danger since 2007) gave us a reason more to investigate this area. \n \nThe study was carried out with four fine quad-pol imagery of the Canadian satellite RADARSAT-2, launched in December 2007. The images were scheduled and provided by VigiSat, in the frame of the GIS BRETEL and processed with the PolSARpro software. However C-band lower capability of penetration compared to ALOS PALSAR L-band, the choice of this satellite is due to its higher spatial resolution compared to the PALSAR one, whose data were employed in a previous study. Thanks to the higher spatial resolution and the location of the site in a semi desert area, we succeeded in balancing a probable lower waves penetration. \nOur analysis focused on four polarimetric images, two with a 23° incidence angle and two with a 45° incidence angle, acquired in different moments of the year 2012. The difference between the angles was motivated, respectively, by the possibility of a higher penetration of the microwaves in the ground and by the higher possibility of double bounce response in the case of presence of buried structures. The time spacing, on the other hand, allowed a temporal analysis over different months of the same year accompanied by meteorological condition available on the web for the zone. \nThe potentiality of this SAR research for archaeology is well known, in particular for those areas of the Globe where surveys in situ are not allowed because of political instability (as in the case of Samarra), or for those zones in which a cloud cover is always present and where optical satellites cannot acquire as radar does in any kind of illumination and in any sky coverage. As known there are still some limitations due to several natural factors (condition in soil humidity is the most important) and due to technical aspects (spatial resolution, inappropriate wave-band), that we hope will be settled in the near future.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| 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 | 0,003 | 0,003 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 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) | 0,002 | 0,001 |
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 source (Gemma direct ou Codex distillé), 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 ».