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Mapping of hydrothermal alternation zones and regional rock types using computer enhanced ERTS MSS imagesA combination of digital computer processing and color compositing of ERTS MSS images has been used to map hydrothermal alternation zones and regional rock types in south-central Nevada. The technique is based on enhancement of subtle visible and near infrared reflectivity differences between mineralogically dissimilar rocks, especially unaltered and altered rocks. MSS spectral bands are ratioed, pixel by pixel, in the computer and subsequently stretched. These ratio values are used to produce a new black and white image which shows the subtle spectral reflectivity differences. Additional enhancement is achieved by preparing color composites of two or more stretched ratio images. The choice of MSS bands for rationing depends on the spectral reflectance properties of the rocks to be discriminated. Although this technique is in the initial stage of development and is untested in other areas, it already appears to have considerable potential for targeting mineral prospects and for regional geologic mapping.
Document ID
19740022648
Document Type
Conference Paper
Authors
Rowan, L. C.
(Geological Survey Reston, VA, United States)
Wetlaufer, P. H.
(Geological Survey Reston, VA, United States)
Billingsley, F. C.
(JPL)
Goetz, A. F. H.
(JPL)
Date Acquired
August 7, 2013
Publication Date
January 1, 1974
Publication Information
Publication: NASA. Goddard Space Flight Center 3d ERTS-1 Symp., Vol. 1, Sect. A
Subject Category
Geophysics
Report/Patent Number
PAPER-G16
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19740022592Analytic PrimaryThird Earth Resources Technology Satellite-1 Symposium. Volume 1: Technical Presentations, section A
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