Mustafa BOLCA, Yusuf KURUCU, A.H. EL-NAHRY, Ünal ALTINBAŞ

Using advanced spectral anlayses techniques as possible means of identifying clay minerals

izmir ilinin güneyinde bulunan Küçük Menderes deltası topraklarında kil mineral tiplerinin belirlenmesinde uzaktan algılama tekniklerinden spektral analiz tekniği kullanılmıştır. Bu amaçla çalışma alanına ait TM görüntülerinin yansıma kalibrasyonu yapılmıştır. Minimum Noise Fraction (MNF) yöntemi ile görüntüdeki bozukluklar gerekli matematiksel algoritmalar kullanılarak azaltılmıştır. Pixel Purity Index (PPI) tekniği kullanılarak görüntünün piksel boyutundaki mineral tanecik yansımaları belirlenmiştir. MNF ve PPI teknikleri beraberce kullanılmış ve 3 boyutlu görünüm yardımıyla en iyi yansımayı veren piksellerin yerini bulmak, tanımlamak ve sınıflandırarak ayrımlı mineraller için en iyi spektral yansımalar belirlenmiştir. Çalışma alanına ait bilinmeyen spektral yansıma analizleri minerallerin yansıma özellikleri ile karşılaştırılmışım Spectral Feature Fitting (SFF), Spectral Angle Mapper (SAM) ve Binary Encoding (BE) teknikleri kullanılarak spektral yansımalarla mineral yansımaları arasında eşleştirilme yapılarak ayrımlı mineral tipleri belirlenmiştir. Bu yöntemlerde O ile l arasında değişen sayılar kullanılmıştır, l en uygun eşlemeye karşılık gelen spektral özellik olup, bir mineralin spektral özelliğine tam olarak uyan yansımayı göstermektedir. Çalışma alanı topraklarında bulunma yoğunluğuna göre kil mineralleri vermikulit, kaolinit, illit ve montmorillonit'tir. Kullanılan spektral yöntemlerde bulunan minerallere ait spektral değerlerin doğruluk analizleri için spektral analizlerin yapıldığı alanlardan toprak örnekleri alınmış ve toprak örneklerinin X-ray sonuçlan ile spektral analiz sonuçları arasında pozitif ilişki belirlenmiştir.

İleri spektral analiz teknikleri kullanılarak kil minerallerinin belirlenebilirliği

Spectral analyses, one of the most advanced remote sensing techniques, were used as a possible means of identifying the mineralogy of the clay fractions that corresponded to the Küçük Menderes Plain, south of Izmir, Turkey. Different spectral processes were used to execute the prospective spectral analyses. The processes include: i. the reflectance calibration of TM images belonging to the studied area, ii. using minimum noise fraction (MNF) transformation and iii. creating the pixel purity index (PP1), which was used to the most "spectrally pure", extreme, pixel in multi-spectral images. Spectral analyses of the clay mineralogy of the studied 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 4 clay minerals i.e., vermiculite, kaolinite, montmorillonite and illite, recording different scores related to their abundance in the soils. In order to check the validity and accuracy of the results obtained regarding the spectral signatures of the minerals identified, soil samples taken from the same localities were subjected to X- ray analysis. As a result a good correlation was found between the spectral signatures and the X- ray diffractions.

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