TITLE:
Assessment and Evaluation of Band Ratios, Brovey and HSV Techniques for Lithologic Discrimination and Mapping Using Landsat ETM+ and SPOT-5 Data
AUTHORS:
Ahmed Madani
KEYWORDS:
Landsat ETM+ Data; SPOT-5 Panchromatic Image; Band Ratios-Brovey and HSV Techniques
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.1,
January
21,
2014
ABSTRACT:
This study aims to assess and to evaluate band ratios,
brovey and HSV (Hue-Saturation-Value) techniques for discrimination and mapping
the basement rock units exposed at Wadi Bulghah area, Saudi Arabia using multispectral
Landsat ETM+ and SPOT-5 panchromatic data.FieldSpec instrument is
utilized to collect the spectral data of diorite, marble, gossan and volcanics,
the main rock units exposed at the study area. Spectral profile of diorite
exhibits very distinguished absorption features around 2.20 μm and
2.35 μm wavelength regions. These absorption features lead to lowering the
band ratio values within the band-7 wavelength region. Diorite intrusions
appear to have grey and dark grey image signatures on 7/3 and 7/2 band ratio
images respectively. On the false color composite ratio image (7/3:R; 7/2:G and
5/2:B), diorite, marble, gossan and volcanics have very dark brown, dark
blue, white and yellowish brown image signatures respectively. Image
fusion between previously mentioned FCC ratio image and high
spatial resolution (5 meters) SPOT-5 panchromatic image is carried out by using brovey and HSV transformation methods. Visual and statistical
assessment methods prove that HSV fused image yields best
image interpretability results rather than brovey image. It improves the spatial
resolution of the original FCC ratios image with acceptable spectral
preservation.