MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone
A validation of the 2005 500m MODIS vegetation continuous fields (VCF) tree cover product in the circumpolar taiga-tundra ecotone was performed using high resolution Quickbird imagery. Assessing the VCF's performance near the northern limits of the boreal forest can help quantify the accuracy o...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20100020839 2023-05-15T18:30:32+02:00 MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone Sun, G. Ranson, K. J. Nelson, R. Kerber, A. Montesano, P. M. Margolis, H. Unclassified, Unlimited, Publicly available July 14, 2009 application/pdf http://hdl.handle.net/2060/20100020839 unknown Document ID: 20100020839 http://hdl.handle.net/2060/20100020839 Copyright, Distribution as joint owner in the copyright CASI Earth Resources and Remote Sensing Remote Sensing of Environment; Volume 113; Issue 10; 2130-2141 2009 ftnasantrs 2018-06-09T22:58:03Z A validation of the 2005 500m MODIS vegetation continuous fields (VCF) tree cover product in the circumpolar taiga-tundra ecotone was performed using high resolution Quickbird imagery. Assessing the VCF's performance near the northern limits of the boreal forest can help quantify the accuracy of the product within this vegetation transition area. The circumpolar region was divided into longitudinal zones and validation sites were selected in areas of varying tree cover where Quickbird imagery is available in Google Earth. Each site was linked to the corresponding VCF pixel and overlaid with a regular dot grid within the VCF pixel's boundary to estimate percent tree crown cover in the area. Percent tree crown cover was estimated using Quickbird imagery for 396 sites throughout the circumpolar region and related to the VCF's estimates of canopy cover for 2000-2005. Regression results of VCF inter-annual comparisons (2000-2005) and VCF-Quickbird image-interpreted estimates indicate that: (1) Pixel-level, inter-annual comparisons of VCF estimates of percent canopy cover were linearly related (mean R(sup 2) = 0.77) and exhibited an average root mean square error (RMSE) of 10.1 % and an average root mean square difference (RMSD) of 7.3%. (2) A comparison of image-interpreted percent tree crown cover estimates based on dot counts on Quickbird color images by two different interpreters were more variable (R(sup 2) = 0.73, RMSE = 14.8%, RMSD = 18.7%) than VCF inter-annual comparisons. (3) Across the circumpolar boreal region, 2005 VCF-Quickbird comparisons were linearly related, with an R(sup 2) = 0.57, a RMSE = 13.4% and a RMSD = 21.3%, with a tendency to over-estimate areas of low percent tree cover and anomalous VCF results in Scandinavia. The relationship of the VCF estimates and ground reference indicate to potential users that the VCF's tree cover values for individual pixels, particularly those below 20% tree cover, may not be precise enough to monitor 500m pixel-level tree cover in the taiga-tundra transition zone. Other/Unknown Material taiga Tundra NASA Technical Reports Server (NTRS) |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Earth Resources and Remote Sensing |
spellingShingle |
Earth Resources and Remote Sensing Sun, G. Ranson, K. J. Nelson, R. Kerber, A. Montesano, P. M. Margolis, H. MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone |
topic_facet |
Earth Resources and Remote Sensing |
description |
A validation of the 2005 500m MODIS vegetation continuous fields (VCF) tree cover product in the circumpolar taiga-tundra ecotone was performed using high resolution Quickbird imagery. Assessing the VCF's performance near the northern limits of the boreal forest can help quantify the accuracy of the product within this vegetation transition area. The circumpolar region was divided into longitudinal zones and validation sites were selected in areas of varying tree cover where Quickbird imagery is available in Google Earth. Each site was linked to the corresponding VCF pixel and overlaid with a regular dot grid within the VCF pixel's boundary to estimate percent tree crown cover in the area. Percent tree crown cover was estimated using Quickbird imagery for 396 sites throughout the circumpolar region and related to the VCF's estimates of canopy cover for 2000-2005. Regression results of VCF inter-annual comparisons (2000-2005) and VCF-Quickbird image-interpreted estimates indicate that: (1) Pixel-level, inter-annual comparisons of VCF estimates of percent canopy cover were linearly related (mean R(sup 2) = 0.77) and exhibited an average root mean square error (RMSE) of 10.1 % and an average root mean square difference (RMSD) of 7.3%. (2) A comparison of image-interpreted percent tree crown cover estimates based on dot counts on Quickbird color images by two different interpreters were more variable (R(sup 2) = 0.73, RMSE = 14.8%, RMSD = 18.7%) than VCF inter-annual comparisons. (3) Across the circumpolar boreal region, 2005 VCF-Quickbird comparisons were linearly related, with an R(sup 2) = 0.57, a RMSE = 13.4% and a RMSD = 21.3%, with a tendency to over-estimate areas of low percent tree cover and anomalous VCF results in Scandinavia. The relationship of the VCF estimates and ground reference indicate to potential users that the VCF's tree cover values for individual pixels, particularly those below 20% tree cover, may not be precise enough to monitor 500m pixel-level tree cover in the taiga-tundra transition zone. |
format |
Other/Unknown Material |
author |
Sun, G. Ranson, K. J. Nelson, R. Kerber, A. Montesano, P. M. Margolis, H. |
author_facet |
Sun, G. Ranson, K. J. Nelson, R. Kerber, A. Montesano, P. M. Margolis, H. |
author_sort |
Sun, G. |
title |
MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone |
title_short |
MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone |
title_full |
MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone |
title_fullStr |
MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone |
title_full_unstemmed |
MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone |
title_sort |
modis tree cover validation for the circumpolar taiga-tundra transition zone |
publishDate |
2009 |
url |
http://hdl.handle.net/2060/20100020839 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
taiga Tundra |
genre_facet |
taiga Tundra |
op_source |
CASI |
op_relation |
Document ID: 20100020839 http://hdl.handle.net/2060/20100020839 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766214060507922432 |