Remote sensing signature analysis of ASTER imagery for geological mapping of Gasus area, central eastern desert, Egypt
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REVIEW PAPER
Remote sensing signature analysis of ASTER imagery for geological mapping of Gasus area, central eastern desert, Egypt Osama El Ghrabawy 1 & Nehal Soliman 2 & Ahmed Tarshan 1,3 Received: 2 May 2018 / Accepted: 16 May 2019 / Published online: 26 June 2019 # Saudi Society for Geosciences 2019
Abstract The using of processed ASTER images and ASTER-GDEM (Advanced Spaceborne Thermal Emission and Reflection Radiometer-global digital elevation model) supplemented by extensive geological field work and spectral measurements of field samples enabled the creating of a new geological map of Gasus area. SVM (Support Vector Machine) method obtained 86% as overall accuracy of the classification and was verified by previous published maps and field verifications. Structure lineaments were automatically extracted and directional analysis of the automatically extracted lineament maps showing that the major trend of the lineaments are NW-SE and NNW-SSE, while NNE-SSW and NE-SW trends can also be recognized but in a less significant order. These trends are compatible and corresponding to the field verification. Keywords ASTER-GDEM . Supervised classification . SVM . And SAM
Introduction By the advent of the multispectral sensors, such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), several geological and mineralogical studies were carried out through the analysis of absorption features of specific minerals providing a scientific background for the interpretation of remotely sensed spectroscopic data (Crowley, 1986). Each Editorial handling: Nilanchal Patel * Osama El Ghrabawy [email protected]
mineral has a specific spectral signature depending on various crystallographic factors. Analyzing the measured spectra of a rock gives information about rock composition, mineral proportions, and crystallinity to provide insight in geological processes, such as magmatic differentiation, regional and contact metamorphism, hydrothermal alteration, and weathering (Pontual et al., 1997). The ASTER data have been chosen because of its relatively good spatial resolution, which make them suitable for mapping geological rock units. The aim of this study is to establish a geological map for the area under investigation, which is created by mapping the surface structure lineaments using ASTER-GDEM (global digital elevation model) and mapping the main rock units using ASTER data.
Nehal Soliman [email protected] Ahmed Tarshan [email protected] 1
Airborne Geophysics Department, Exploration Division, Nuclear Material Authority, P.O. Box 530, Maadi, Cairo, Egypt
2
Remote Sensing and Geographic Information system, Geological Department, National Authority for Remote Sensing & Space Sciences, Cairo, Egypt
3
Institute of Earth Science, Geophysics Department, Saint Petersburg State University, Saint Petersburg, Russia
Overview of the study area The present study area is located in the upper central eastern desert between latitude 26°21′22″ to 26°36′ 02″ N and longitude 33°39′22″ to 33°57′5
