Les images satellitaires Radar. Utilisation en cartographie géologique et exploration minière (Guyane, Côte-d'Ivoire).
Résumé
The aim of the AURROS project conslsted in demonstrating the use of satellite radar data on sites representative of the problems encountered in geological and mineral exploralion. The objective is to improve characterisation methods for target zones, parlicularly in the early stages of the process leading to mining permit application. The dalabase integrales ERS (l and 2) data, RADARSAT (broad-swath Seansar mode and fine bi-angular viewing made) data, DEMs acquired by various means, and geophysical dala (airborne magnelics, spectral radiomelry). Various me/hods (fil/ering, geocoding and stereoscopy) have heen integrated or developed by BRGM to create differenl map types. These dala are analysed at various scales and validated using hvo approaches, namely checking in Ihe field and fusion wilh airhome geophysical data (spectral radiometry and aeromagnetics). The first results showed the radar to be a powerful mapping and deposit-prediction tool, and notably revealed that 1) the raw data con be used directly by geologists either for standard geological studies or as an exploration aid, and 2) fusion with geophysical data enables the identification of deformation structures where geophysics alone only reveals large masses, and rapidly and efficiently increases the possibilities of lithological discrimination. Correct use of the data nevertheless involves taking into consideration the scales used and currenl restrictions concerning the most suitable study environments. The development possibilities associated with radar stereoscopy constitute a major progress factor for the near future.
Origine : Accord explicite pour ce dépôt
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