PowerPoint-Pr

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Tree height estimation from multi-temporal ERS
SAR interferometric phase
M. Santoro(1), J. Askne(2), P. B. G. Dammert(3)
(1) Friedrich-Schiller-University Jena (2)
Chalmers University of Technology (3)
Ericsson Microwave AB Jena, Germany
Gothenburg, Sweden Mölndal, Sweden
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Introduction
Question How feasible is tree height retrieval
from ERS InSAR phase?
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InSAR Phase
The InSAR phase can be used to determine the
topography of an area
What happens in a forest?
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Test sites

• Kättböle, Sweden
• Forest stands estate 5.5 km2
• Intensively managed forest
• Boreal coniferous
• 42 stands gt 2 ha
• Tree height 2-23 m
• 9 ERS-1/2 pairs

• Tuusula, Finland
• Mixed forest landscape 20 km2
• Intensively managed forest
• Boreal, coniferous
• 6 stands gt 10 ha
• Tree height 10-27 m
• 8 ERS-1/2 pairs

• Bois de Boulogne, Paris
• Park 9 km2
• Urban environment
• Temperate, deciduous
• 4 stands gt 20 ha
• Tree height 18-23 m
• 9 ERS-1/2 pairs

• Thüringer Wald, Germany
• Forests 40x10 km2
• Managed forests, mountains, fields
• Temperate, coniferous
• 5 ERS-1/2 pairs

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Atmospheric artefacts
Approaches to atmospheric filtering
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Interferometric tree height
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Interferometric Water Cloud Model
The total forest coherence is a sum of 2
contributions
Ground coherence, ?gr Vegetation coherence,
?veg
Model considers tree attenuation (?), gaps (?),
InSAR geometry (?)
Interferometric tree height
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Modelling

• Estimate model unknowns s 0veg, s 0gr, b, ?veg
  and ?gr.
• Non-linear regression using (?, V) and (s 0,V)
  measurements
• Accurate measurements
• 3. InSAR phase does not affect the regression

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Tree height retrieval
Vegetation height
Interferometric tree height
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Conclusions

• ?
• More knowledge about InSAR phase properties in
  forests
• IWCM describes the forest topographic effects
  well

• ?
• Compensation of atmospheric artefacts difficult
  in large forests
• Phase noise is dominant
• Number of useful InSAR pairs is small
• Tree height estimation is limited