TITLE:
Mapping of Aluminous Rich Laterite Depositions through Hyper Spectral Remote Sensing
AUTHORS:
M. J. Ratnakanth Babu, E. N. Dhanamjaya Rao, Lalitha Kallempudi, Das Iswar Chandra
KEYWORDS:
Hyperspectral Remote Sensing, Aluminous Rich Laterite, Imaging Spectroscopy, Hydro Thermal Altered Ores
JOURNAL NAME:
International Journal of Geosciences,
Vol.9 No.2,
February
13,
2018
ABSTRACT: Increased dimensionality of the satellite data proves to be very useful for discriminating
features with very close spectral matching. Present study concentrates
on the retrieval of reflectance spectra from the level one radiometrically
corrected data in Koraput district (Orissa) for the Bauxite ore. In the present
study, atmospheric correction model FLAASH has been used to retrieve reflectance
from the radiance data. Preprocessing of the dataset has been done
before applying atmospheric correction on the dataset. Spectral subsetting of
noise prone bands has been successfully done. Local destriping of the affected
bands has been done using a 3*3 local mean filter. Spectral signatures of samples
were derived from the processed data. Spectral signature of each sample
and derived features vectors were correlated with the satellite image of the
area and distribution of each feature was demarcated. Spatial abundance of
each feature was used in preparation of mineral abundance map. Accuracy of
the map was assessed using training sets of representative geological units.
The mineral abundance mapping using the spectral analysis of the reflectance
image involves the endmember collection using the N-Dimensional visualizer
tool in ENVI software. Laterite, Bauxite, Iron and silica rich Aluminous laterite
soil, Alluvium and Forest were selected as the end members after understanding
the geology and analysis of the reflectance image. Various mapping
techniques were applied to generate the final classified mineral abundance
Map, Linear Spectral Unmixing, Mixture Tune Matched Filtering, Spectral
Feature Fitting, Spectral Angle Mapper were the techniques used. Results have
revealed the ability of Hyper spectral Remote sensing data for the identification
and mapping of Hydrothermal altered products like Bauxite, Aluminous Laterite. This technology can be utilized for targeting minerals in the altered
zone.