Hyperspectral Remote Sensing and Zone of Degasification in Part of Sabatayn Basin-Yemen

摘要

Aster data of the Sabatyayn Basin,was used to evaluate the potential of hyperspectral data to identify possible mineral alteration associated with petroleum hydrocarbon microseeps.Spectral analyses,one of the most advanced remote sensing techniques,were used as a possible means of identifying the altered minerals.Different spectral processes were used to execute the prospective spectral analyses.The processes include: i.the atmospheric correction(FLAASH)of Aster images belonging to the study area,ii.using minimum noise fraction(MNF)transformation and iii.Creating the pixel purity index(PPI),which was used to the most”spectrally pure”,extreme,pixel in multi-spectral images.Spectral analyses of the altered minerals of the study area were obtained by matching the unknown spectra of the purest pixels to pre-defined(library)spectra providing scores with respect to the library spectra.Three methods,namely Spectral Feature Fitting(SFF),Spectral Angle Mapper(SAM)and Binary Encoding(BE)were used to produce a score between 0 and 1,where the value of 1 equals a perfect match showing the exact mineral type.We were able to identify 5 possible altered minerals i.e.,alunite,kaolinite,calcite,siderite and halloysite,recording different scores related to their abundance in the soils.Spectral Feature Fitting(SFF)Mapping techniques were used to classify minerals in the images.