Potential Use of ASTER Derived Emissivity, Thermal Inertia and Albedo Image for Discriminating Different Rock Types of Aravalli Group of Rocks, Rajasthan

Abstract

In the present study, broad band emissivity, apparent thermal inertia and albedo image products have been derived based on processing of Advanced Spaceborne Thermal Emission and reflection (ASTER) data and analyzed their potential for delineating different metasedimentary units of Aravalli Group in Rajasthan. The major focus of the work is to analyze the potential of emissivity bands with respect to conjugated image product of emissivity, albedo and inertia for discriminating different rock types. In this regard, it was observed that combined use of emissivity, thermal inertia and albedo was effective for delineating different rock types as the combined variation of thermo-physical and mineralogical properties were recorded in these parameters. On the other hand, broad band emissivity spectra of rocks of the study area had subtle contrast, which was not optimum for the discrimination of different rock types. This was evident in the ASTER derived emissivity composite in which spatial delineation of rocks of the study area was not possible. Therefore, it is concluded that the combined use of albedo, thermal inertia and emissivity was suitable to delineate different metasedimentary rocks. This was also evident from the three dimensional data plot of selected emissivity band, inertia and albedo which separated different rocks from one another.