Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra
Satellites provide the only practical source of data for estimating biomass of large and remote areas such as the Alaskan Arctic. Researchers have found that the normalized difference vegetation index (NDVI) correlates well with biomass sampled on the ground. However, errors in NDVI and biomass esti...
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ftdoajarticles:oai:doaj.org/article:43734ba018044971a321e923930b411c 2023-09-05T13:11:19+02:00 Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra Marcel Buchhorn Martha K Raynolds Donald A Walker 2016-01-01T00:00:00Z https://doi.org/10.1088/1748-9326/11/12/125002 https://doaj.org/article/43734ba018044971a321e923930b411c EN eng IOP Publishing https://doi.org/10.1088/1748-9326/11/12/125002 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/11/12/125002 1748-9326 https://doaj.org/article/43734ba018044971a321e923930b411c Environmental Research Letters, Vol 11, Iss 12, p 125002 (2016) biomass BRDF anisotropy effects NDVI Alaska North Slope Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 article 2016 ftdoajarticles https://doi.org/10.1088/1748-9326/11/12/125002 2023-08-13T00:37:52Z Satellites provide the only practical source of data for estimating biomass of large and remote areas such as the Alaskan Arctic. Researchers have found that the normalized difference vegetation index (NDVI) correlates well with biomass sampled on the ground. However, errors in NDVI and biomass estimates due to bidirectional reflectance distribution function (BRDF) effects are not well reported in the literature. Sun-sensor-object geometries and sensor band-width affect the BRDF, and formulas relating NDVI to ground-sampled biomass vary between projects. We examined the effects of these different variables on five studies that estimated above-ground tundra biomass of two common arctic vegetation types that dominate the Alaska tundra, moist acidic tussock tundra (MAT) and moist non-acidic tundra (MNT). We found that biomass estimates were up to 33% (excluding extremes) more sensitive than NDVI to BRDF effects. Variation between the sensors resulted in differences in NDVI of under 3% over all viewing geometries, and wider bands were more stable in their biomass estimates than narrow bands. MAT was more sensitive than MNT to BRDF effects due to irregularities in surface reflectance created by the tussocks. Finally, we found that studies that sampled only a narrow range of biomass and NDVI produced equations that were more difficult to correct for BRDF effects. Article in Journal/Newspaper Alaska North Slope Arctic north slope Tundra Alaska Directory of Open Access Journals: DOAJ Articles Arctic Environmental Research Letters 11 12 125002 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
biomass BRDF anisotropy effects NDVI Alaska North Slope Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
spellingShingle |
biomass BRDF anisotropy effects NDVI Alaska North Slope Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 Marcel Buchhorn Martha K Raynolds Donald A Walker Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra |
topic_facet |
biomass BRDF anisotropy effects NDVI Alaska North Slope Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
description |
Satellites provide the only practical source of data for estimating biomass of large and remote areas such as the Alaskan Arctic. Researchers have found that the normalized difference vegetation index (NDVI) correlates well with biomass sampled on the ground. However, errors in NDVI and biomass estimates due to bidirectional reflectance distribution function (BRDF) effects are not well reported in the literature. Sun-sensor-object geometries and sensor band-width affect the BRDF, and formulas relating NDVI to ground-sampled biomass vary between projects. We examined the effects of these different variables on five studies that estimated above-ground tundra biomass of two common arctic vegetation types that dominate the Alaska tundra, moist acidic tussock tundra (MAT) and moist non-acidic tundra (MNT). We found that biomass estimates were up to 33% (excluding extremes) more sensitive than NDVI to BRDF effects. Variation between the sensors resulted in differences in NDVI of under 3% over all viewing geometries, and wider bands were more stable in their biomass estimates than narrow bands. MAT was more sensitive than MNT to BRDF effects due to irregularities in surface reflectance created by the tussocks. Finally, we found that studies that sampled only a narrow range of biomass and NDVI produced equations that were more difficult to correct for BRDF effects. |
format |
Article in Journal/Newspaper |
author |
Marcel Buchhorn Martha K Raynolds Donald A Walker |
author_facet |
Marcel Buchhorn Martha K Raynolds Donald A Walker |
author_sort |
Marcel Buchhorn |
title |
Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra |
title_short |
Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra |
title_full |
Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra |
title_fullStr |
Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra |
title_full_unstemmed |
Influence of BRDF on NDVI and biomass estimations of Alaska Arctic tundra |
title_sort |
influence of brdf on ndvi and biomass estimations of alaska arctic tundra |
publisher |
IOP Publishing |
publishDate |
2016 |
url |
https://doi.org/10.1088/1748-9326/11/12/125002 https://doaj.org/article/43734ba018044971a321e923930b411c |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Alaska North Slope Arctic north slope Tundra Alaska |
genre_facet |
Alaska North Slope Arctic north slope Tundra Alaska |
op_source |
Environmental Research Letters, Vol 11, Iss 12, p 125002 (2016) |
op_relation |
https://doi.org/10.1088/1748-9326/11/12/125002 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/11/12/125002 1748-9326 https://doaj.org/article/43734ba018044971a321e923930b411c |
op_doi |
https://doi.org/10.1088/1748-9326/11/12/125002 |
container_title |
Environmental Research Letters |
container_volume |
11 |
container_issue |
12 |
container_start_page |
125002 |
_version_ |
1776203904334168064 |