1. landsat vs. rapideye tree box s7 e39 (in dash line) 1 3 4 2 5 landsat 17/05/2010 rapideye...
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1. Landsat vs. Rapideye TREE box S7 E39 (in dash line)
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Landsat 17/05/2010 Rapideye 02/07/2010
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Site5
2. Change detection
Landsat 17/5/2010
Rapideye 2/7/2010
Landsat 30/6/2000
Landsat 30/6/2000 Landsat 1/7/2010 Rapideye 2/7/2010
3. Forest cover detectionLandsat 1/7/2010
Rapideye 2/7/2010
VHR image 05/10/2009
Object-based segmentation
Rapideye vs. Landsat
Landsat 2010
Rapideye 2010
Analysis of no-change polygons
Landsat overestimation of logged area
VHR
LS
RE
VHR
LS
RE
Non detection of small forest blocks
82% forest cover
81% forest cover
47% forest cover
VHR
LS
RE
Underestimation of forest cover
y = 0.6111x - 0.1532R² = 0.3624
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st p
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Land
sat
forest proportion - high resolution
Landsat Polygons greater than 0.5 ha
Rapideye vs. Landsat
• In fragmented landscapes, Landsat fails to detect forest in many areas with forest cover of 20-90% (errors of omission)
• In homogeneous landscapes, Landsat fails to detect small canopy openings (errors of forest commission)
• Landsat forest estimates have high variance in those areas with forest cover higher than 90% (inaccuracy and lack of precision).
y = 0.8023x - 0.0648R² = 0.6169
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Sen
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forest proportion - high resolution
'Sentinel' Polygons greater than 0.5 ha
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poly
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forest proportion
Area and detection - Landsat
Rapideye vs. Landsat
• Landsat fails to detect forest in many areas smaller than 1 ha.
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forest proportion
Area and detection 'Sentinel'
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forest proportion
Area and detection - High resolution
Actual distribution of forest cover within polygons from VHR data (just for comparison with the previous slide).
Landsat overestimation of logged area
VHR
LS
SE_S
VHR
LS
SE_S
Non detection of small forest blocks
82 % forest cover
76 % forest cover
47 % forest cover
VHR
LS
SE_S
Underestimation of forest cover