IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND)
Lichens are the dominant autotrophs of polar and subpolar ecosystems commonly encrust the rock outcrops. Spectral mixing of lichens and bare rock can shift diagnostic spectral features of materials of interest thus leading to misinterpretation and false positives if mapping is done based on perfect...
Published in: | The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences |
---|---|
Main Authors: | , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/isprs-archives-XLI-B7-973-2016 https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B7/973/2016/ |
id |
ftcopernicus:oai:publications.copernicus.org:isprs-archives53184 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:isprs-archives53184 2023-05-15T16:28:28+02:00 IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) Salehi, S. Karami, M. Fensholt, R. 2018-01-15 application/pdf https://doi.org/10.5194/isprs-archives-XLI-B7-973-2016 https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B7/973/2016/ eng eng doi:10.5194/isprs-archives-XLI-B7-973-2016 https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B7/973/2016/ eISSN: 2194-9034 Text 2018 ftcopernicus https://doi.org/10.5194/isprs-archives-XLI-B7-973-2016 2019-12-24T09:52:14Z Lichens are the dominant autotrophs of polar and subpolar ecosystems commonly encrust the rock outcrops. Spectral mixing of lichens and bare rock can shift diagnostic spectral features of materials of interest thus leading to misinterpretation and false positives if mapping is done based on perfect spectral matching methodologies. Therefore, the ability to distinguish the lichen coverage from rock and decomposing a mixed pixel into a collection of pure reflectance spectra, can improve the applicability of hyperspectral methods for mineral exploration. The objective of this study is to propose a robust lichen index that can be used to estimate lichen coverage, regardless of the mineral composition of the underlying rocks. The performance of three index structures of ratio, normalized ratio and subtraction have been investigated using synthetic linear mixtures of pure rock and lichen spectra with prescribed mixing ratios. Laboratory spectroscopic data are obtained from lichen covered samples collected from Karrat, Liverpool Land, and Sisimiut regions in Greenland. The spectra are then resampled to Hyperspectral Mapper (HyMAP) resolution, in order to further investigate the functionality of the indices for the airborne platform. In both resolutions, a Pattern Search (PS) algorithm is used to identify the optimal band wavelengths and bandwidths for the lichen index. The results of our band optimization procedure revealed that the ratio between R 894-1246 and R 1110 explains most of the variability in the hyperspectral data at the original laboratory resolution (R 2 =0.769). However, the normalized index incorporating R 1106-1121 and R 904-1251 yields the best results for the HyMAP resolution (R 2 =0.765). Text Greenland Sisimiut Copernicus Publications: E-Journals Bare Rock ENVELOPE(-45.589,-45.589,-60.704,-60.704) Greenland Liverpool Land ENVELOPE(-22.200,-22.200,70.917,70.917) Sisimiut ENVELOPE(-53.674,-53.674,66.939,66.939) The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 973 979 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Lichens are the dominant autotrophs of polar and subpolar ecosystems commonly encrust the rock outcrops. Spectral mixing of lichens and bare rock can shift diagnostic spectral features of materials of interest thus leading to misinterpretation and false positives if mapping is done based on perfect spectral matching methodologies. Therefore, the ability to distinguish the lichen coverage from rock and decomposing a mixed pixel into a collection of pure reflectance spectra, can improve the applicability of hyperspectral methods for mineral exploration. The objective of this study is to propose a robust lichen index that can be used to estimate lichen coverage, regardless of the mineral composition of the underlying rocks. The performance of three index structures of ratio, normalized ratio and subtraction have been investigated using synthetic linear mixtures of pure rock and lichen spectra with prescribed mixing ratios. Laboratory spectroscopic data are obtained from lichen covered samples collected from Karrat, Liverpool Land, and Sisimiut regions in Greenland. The spectra are then resampled to Hyperspectral Mapper (HyMAP) resolution, in order to further investigate the functionality of the indices for the airborne platform. In both resolutions, a Pattern Search (PS) algorithm is used to identify the optimal band wavelengths and bandwidths for the lichen index. The results of our band optimization procedure revealed that the ratio between R 894-1246 and R 1110 explains most of the variability in the hyperspectral data at the original laboratory resolution (R 2 =0.769). However, the normalized index incorporating R 1106-1121 and R 904-1251 yields the best results for the HyMAP resolution (R 2 =0.765). |
format |
Text |
author |
Salehi, S. Karami, M. Fensholt, R. |
spellingShingle |
Salehi, S. Karami, M. Fensholt, R. IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) |
author_facet |
Salehi, S. Karami, M. Fensholt, R. |
author_sort |
Salehi, S. |
title |
IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) |
title_short |
IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) |
title_full |
IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) |
title_fullStr |
IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) |
title_full_unstemmed |
IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND) |
title_sort |
identification of a robust lichen index for the deconvolution of lichen and rock mixtures using pattern search algorithm (case study: greenland) |
publishDate |
2018 |
url |
https://doi.org/10.5194/isprs-archives-XLI-B7-973-2016 https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B7/973/2016/ |
long_lat |
ENVELOPE(-45.589,-45.589,-60.704,-60.704) ENVELOPE(-22.200,-22.200,70.917,70.917) ENVELOPE(-53.674,-53.674,66.939,66.939) |
geographic |
Bare Rock Greenland Liverpool Land Sisimiut |
geographic_facet |
Bare Rock Greenland Liverpool Land Sisimiut |
genre |
Greenland Sisimiut |
genre_facet |
Greenland Sisimiut |
op_source |
eISSN: 2194-9034 |
op_relation |
doi:10.5194/isprs-archives-XLI-B7-973-2016 https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B7/973/2016/ |
op_doi |
https://doi.org/10.5194/isprs-archives-XLI-B7-973-2016 |
container_title |
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences |
container_volume |
XLI-B7 |
container_start_page |
973 |
op_container_end_page |
979 |
_version_ |
1766018122059350016 |