Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination
Hyperspectral imagery of a vertical mine face acquired from a field-based platform is used to evaluate the effects of different conditions of illumination on absorption feature parameters wavelength position, depth and width. Imagery was acquired at different times of the day under direct solar illu...
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doaj-e3f8c617e0d8484290be72832cb647722020-11-24T20:49:00ZengMDPI AGRemote Sensing2072-42922014-09-01699104912910.3390/rs6099104rs6099104Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of IlluminationRichard J. Murphy0Sven Schneider1Sildomar T. Monteiro2Australian Centre for Field Robotics, Department of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, The Rose Street Building J04, NSW 2010, AustraliaAustralian Centre for Field Robotics, Department of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, The Rose Street Building J04, NSW 2010, AustraliaCenter for Imaging Science and Department of Electrical and Microelectronic Engineering, Rochester Institute of Technology, 79 Lomb Memorial Drive, Rochester, NY 14623, USAHyperspectral imagery of a vertical mine face acquired from a field-based platform is used to evaluate the effects of different conditions of illumination on absorption feature parameters wavelength position, depth and width. Imagery was acquired at different times of the day under direct solar illumination and under diffuse illumination imposed by cloud cover. Imagery acquired under direct solar illumination did not show large amounts of variability in any absorption feature parameter; however, imagery acquired under cloud caused changes in absorption feature parameters. These included the introduction of a spurious absorption feature at wavelengths > 2250 nm and a shifting of the wavelength position of specific clay absorption features to longer or shorter wavelengths. Absorption feature depth increased. The spatial patterns of clay absorption in imagery acquired under similar conditions of direct illumination were preserved but not in imagery acquired under cloud. Kaolinite, ferruginous smectite and nontronite were identified and mapped on the mine face. Results were validated by comparing them with predictions from x-ray diffraction and laboratory hyperspectral imagery of samples acquired from the mine face. These results have implications for the collection of hyperspectral data from field-based platforms.http://www.mdpi.com/2072-4292/6/9/9104Hyperspectralclay mineralsabsorption featuremine-faceremote sensing |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Richard J. Murphy Sven Schneider Sildomar T. Monteiro |
spellingShingle |
Richard J. Murphy Sven Schneider Sildomar T. Monteiro Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination Remote Sensing Hyperspectral clay minerals absorption feature mine-face remote sensing |
author_facet |
Richard J. Murphy Sven Schneider Sildomar T. Monteiro |
author_sort |
Richard J. Murphy |
title |
Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination |
title_short |
Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination |
title_full |
Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination |
title_fullStr |
Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination |
title_full_unstemmed |
Mapping Layers of Clay in a Vertical Geological Surface Using Hyperspectral Imagery: Variability in Parameters of SWIR Absorption Features under Different Conditions of Illumination |
title_sort |
mapping layers of clay in a vertical geological surface using hyperspectral imagery: variability in parameters of swir absorption features under different conditions of illumination |
publisher |
MDPI AG |
series |
Remote Sensing |
issn |
2072-4292 |
publishDate |
2014-09-01 |
description |
Hyperspectral imagery of a vertical mine face acquired from a field-based platform is used to evaluate the effects of different conditions of illumination on absorption feature parameters wavelength position, depth and width. Imagery was acquired at different times of the day under direct solar illumination and under diffuse illumination imposed by cloud cover. Imagery acquired under direct solar illumination did not show large amounts of variability in any absorption feature parameter; however, imagery acquired under cloud caused changes in absorption feature parameters. These included the introduction of a spurious absorption feature at wavelengths > 2250 nm and a shifting of the wavelength position of specific clay absorption features to longer or shorter wavelengths. Absorption feature depth increased. The spatial patterns of clay absorption in imagery acquired under similar conditions of direct illumination were preserved but not in imagery acquired under cloud. Kaolinite, ferruginous smectite and nontronite were identified and mapped on the mine face. Results were validated by comparing them with predictions from x-ray diffraction and laboratory hyperspectral imagery of samples acquired from the mine face. These results have implications for the collection of hyperspectral data from field-based platforms. |
topic |
Hyperspectral clay minerals absorption feature mine-face remote sensing |
url |
http://www.mdpi.com/2072-4292/6/9/9104 |
work_keys_str_mv |
AT richardjmurphy mappinglayersofclayinaverticalgeologicalsurfaceusinghyperspectralimageryvariabilityinparametersofswirabsorptionfeaturesunderdifferentconditionsofillumination AT svenschneider mappinglayersofclayinaverticalgeologicalsurfaceusinghyperspectralimageryvariabilityinparametersofswirabsorptionfeaturesunderdifferentconditionsofillumination AT sildomartmonteiro mappinglayersofclayinaverticalgeologicalsurfaceusinghyperspectralimageryvariabilityinparametersofswirabsorptionfeaturesunderdifferentconditionsofillumination |
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1716807158779084800 |