The evaluation of digitally enhanced Indian Remote Sensing Satellite (IRS) data for lithological and structural mapping
Author: Krishnamurthy, J.
Source: International Journal of Remote Sensing, Volume 18, Number 16, 1997 , pp. 3409-3437(29)
Publisher: Taylor and Francis Ltd
Abstract:The potential of digitally enhanced Indian Remote Sensing Satellite (IRS) data for preparation of lithological and structural maps is explored in two test sites representing different geological settings in parts of Karnataka. Test site 1 is an area around Mattod, which mainly consists of Chitradurga rocks and peninsular gneiss, and the terrain is characterized by bare soil and is devoid of thick vegetation. Test site 2 is an area around the Bababudan belt, which mainly comprised of Bababudan and Chitradurga rocks and peninsular gneiss, and the major part of the area is covered under thick vegetation. Different digital enhancement techniques have been performed, and the expression of different lithological and structural features in the digitally enhanced products were qualitatively assessed. Based on this assessment, only those products which offered additional information than the standard false colour component (FCC) were selected and utilized along with standard FCC in the preparation of geological and structural maps. Attempts have been made to understand the advantages and limitations of using optical remote sensing data for deriving lithological and structural details. The maps created through using digitally enhanced IRS data have helped to revise/modify the existing geological map prepared through conventional method of mapping to considerable extent in terms of refined lithological boundaries, delineation of unmapped rock units, mapping of lineaments, and their networks. The results of the study has clearly brought out the fact that the geological map prepared from the optical remote sensing data at a shorter time interval is broadly comparable to that of the geological map prepared through conventional techniques over several years. Also the study has highlighted that the broad-band spectral resolution optical remote sensing data can be effectively utilized for lithological and structural demarcation, only when the terrain is: (i) exposed with rock outcrops and their weathered derivatives; (ii) characterized by rock units which greatly differ in terms of physico-chemical properties; and (iii) devoid of vegetation cover.
Document Type: Research Article
Publication date: 1997-11-10