Assessment and Evaluation of Band Ratios, Brovey and HSV Techniques for Lithologic Discrimination and Mapping Using Landsat ETM<sup>+</sup> and SPOT-5 Data

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.

Spectroscopy of olivine basalts using FieldSpec and ASTER data: A case study from Wadi Natash volcanic field, south Eastern Desert, Egypt

“…The false colour composite ratio image (3/2:R; 8/1:G and 8/5:B) discriminates easily the fresh olivine basalt by deep blue colour and altered olivine basalt by reddish blue colour. Several authors dealt with the assessment and evaluation of fusion techniques (Marcelino et al 2009;Klonus and Ehlers 2009;Madani 2014). Visual and statistical assessment methods are used to ensure the improvement of spatial resolution and preservation of spectral characteristics of the original band ratios false colour composite image.…”

Sequential Band-Ratio in Landsat 8 OLI/TIRS to Enhance the Suspended Sediment Direction Monitoring in Urban Coastal Area

“…2). Band ratio has been widely used for its high effectiveness in identifying shoreline changes (Madani & Madani, 2014;Sutari et al, 2020;Trihatmoko, 2017). The band ratio R formulation derived from the ratio of the digital number DN of the particular band m to the other band n as follows:…”

Spatial Analysis of Linear Structures in the Exploration of Groundwater

“…Band ratios based on the notion of reflectance reduced the topography effects and enhanced the contrast reflections between mineral surfaces [16][17][18]. Ratios TM4/TM3, TM4/TM5, and TM4/TM7 were realized, and the colored compositions generated from the neo-bands allowed lithological identification ( Figure 4).…”