Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Evaluating the potential of satellite data to classify tree species and multiple stages of
tree damages
Lars Waser Kai JütteTheresia Stampfer
Landesforst Mecklenburg-VorpommernAnstalt des öffentlichen Rechts
Betriebsteil Forstplanung, Versuchswesen, Forstliche Informationssysteme
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Tornado „Doris“
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Situation / goals
Tornado „Doris“ – severe storm & hail; 11 June 2010
> 2000 ha of forest affected / destroyed
=> Focus on detecting multiple stages of tree damages (ash / Scots pine)
=> Which tree species are affected most? (tree species classification)
Which satellite system is most appropriate? (costs, Pros / Cons)
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Study areasGerman State Mecklenburg-Vorpommern
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Satellite data
- Passive optical system, 2 m- 8 bands RGBI, costal, yellow, NIR2, Rededge
WorldView-2 images - Active system, X-band (3 cm)- 1.25 m
TerraSAR-X images
4/13
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Training / reference data 7 Tree species: Delineated tree crown polygons (756)
4 stages of tree damages (ash / Scots pine): 4 x 120 polygons
=> Ash, beech, Douglas fir, larch, Norway spruce, oak, poplar
Terr
estri
al
surv
eyC
row
n vi
ew
from
a c
rane
1 (0-25%) 2 (25-50%) 3 (50-75%) 4 (75-100%)destroyed foliage
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
In-situ spectral measurements
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e.g. damage stage 3
a mobile crane Aerial images
Terrestrial survey
Crown view from:
WorldView-2 images
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Training / reference data
- Delineated tree crown polygons (756)Different stages of damaged Scots pine (2011)
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Classification Pre-processing - De-Hazing+Atmospheric Correction
- Original bands & 22 Vegetation indices
- 20 indices (filters, textural & structural)
Signatures (variables)
Validation of prediction: external, independent reference data (polygons)
- Noise reduction
Multinomial log. regression
- Cross-Validation (10-fold)
- Variable selection
- Image segmentations
8/13
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Results
TerraSAR-X
Waser et al. in prep. for Remote Sensing of Environment
WorldView-2
7 tree species
ash
Scots pine
Overallacc.
Overallacc.kappa kappa
0.90 0.83 0.310.56
=> ash and poplar > 0.7
ash, beech, Douglas fir, larch, Norway spruce, oak, poplar
Stage of damage
1 32 4 1 32 4
0.83 0.730.65 0.78 0.62 0.520.44 0.56
0.78 0.710.62 0.72 0.62 0.530.39 0.59
10-fold cross-validated
9/13
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Results
TerraSAR-X
Waser et al. in prep. for Remote Sensing of Environment
WorldView-2
7 tree species
ash
Scots pine
Overallacc.
Overallacc.kappa kappa
0.90 0.83 0.310.56
=> ash and poplar > 0.7
ash, beech, Douglas fir, larch, Norway spruce, oak, poplar
Stage of damage
1 32 4 1 32 4
0.83 0.730.65 0.78 0.62 0.520.44 0.56
0.78 0.710.62 0.72 0.62 0.530.39 0.59
10-fold cross-validated
9/13
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Results
TerraSAR-X
Waser et al. in prep. for Remote Sensing of Environment
WorldView-2
7 tree species
ash
Scots pine
Overallacc.
Overallacc.kappa kappa
0.90 0.83 0.310.56
=> ash and poplar > 0.7
ash, beech, Douglas fir, larch, Norway spruce, oak, poplar
Stage of damage
1 32 4 1 32 4
0.83 0.730.65 0.78 0.62 0.520.44 0.56
0.79 0.710.62 0.76 0.62 0.530.39 0.59
10-fold cross-validated
9/13
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Overall accuracies of prediction (independent reference data) 81% 50%
WorldView-2 versus TerraSAR-X: tree species
WorldView-2 TerraSAR-X
10/13
Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
WorldView-2 versus TerraSAR-X: damaged ash
WorldView-2 TerraSAR-X
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
WorldView-2 versus TerraSAR-X: damaged Scots pine
WorldView-2 TerraSAR-X
Overall accuracies of prediction (independent reference data) 72% 35%
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
Conclusions & outlook
Multispectral WorldView-2 have a high potential for classifying: - tree species (7)
- 4 different stages of damaged ash and Scots pine
TerraSAR-X data less (not) appropriate (exceptions)
Calculation of indices significantly (p = 0.01) improved classification accuracies
Reasonable amount of effort regarding data acquisition and pre-processing
Testing aerial images (lower costs, more flexible)
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Evaluating the potential of satellite data to classify tree species and multiple stages of tree damages
RU-Science Day 4 June 2013
13/13
Thank you!
