examples of formosat-2 data use: nezer-arcachon datasets framework:
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Examples of Formosat-2 data use: Nezer-Arcachon datasets Framework: Vegetation and environnement monitoring of agriculture and forest landscapes in Aquitaine under global change (climate, anthropogenic activities) Dominique Guyon, INRA Bordeaux, Unité EPHYSE. Formosat2/VENµS Users meeting - PowerPoint PPT PresentationTRANSCRIPT
Examples of Formosat-2 data use:
Nezer-Arcachon datasets
Framework:
Vegetation and environnement monitoring of agriculture and forest landscapes in Aquitaine under global change (climate, anthropogenic activities)
Dominique Guyon, INRA Bordeaux, Unité EPHYSE
Formosat2/VENµS Users meeting
CESBIO, Toulouse, January 12th 2010
Venµs, Formosat-2 : high spatial resolution + high repetitivity
-> separate immediate changes due to agricultural practices operating at field level from those due to natural environment (soil, climate).
-> complementary approaches:
- monitoring the seasonal/interannual changes of the remote sensing signal (e.g. NDVI, red-edge bands reflectance):
dating phenological stages,
dating and detecting agricultural activities (sowing, thinning out of leaves, harvest, felling…),
detecting events of climate accidents (storm), stress or early senescence
- mapping of vegetation based on seasonal changes during the whole year
- retrieval of the annual course of biophysical variables at plot scale : LAI, Fcover, faPAR
- assessing the information loss due to a scaling from local measurements to low resolution remote sensing time-series (e.g. VEGETATION or MODIS).
- coupling to process-based models: biomass production, crop yield, productivity, C and water fluxes
VENµS: Propositions de sites
UR EPHYSE (terrestrial ecosystems)
UMR EPOC (maritime ecosystems)
FORMOSAT2: Database KALIDEoS-Littoral / CNES
KALIDEOS-Littoral
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2
3
Some INRA’s sites:1: NEZER (forest landscape) and BILOS (fluxes meas.)2, 3: Watersheds of Bouron, Tagon
► forest structure changes monitoring with VHR imagery
Programm ORFEO/Cnes, PhD 2010-2013?
Collaboration EGID-Univ. Bordeaux3
• Nezer
•Climate events and sylvicultural changes (thinning, felling)
•application to map the 24th January 2009 windfall damages
► Phenology monitoring
tree layer and understory vegetation
•Bilos ; 2008-2009
•Ground-based measurements of LAI and fAPAR,
•Seasonal change of vegetation indices from Spot/VEGETATION
•Formosat/VEGETATION: to be done
FORMOSAT2:
- time-series 2008-2009
NEZER + Bilos
14/03/200821/08/200822/12/2008 Storm on January 2904/02/200929/05/200924/06/200916/06/200913/08/200907/09/2009
- after 2009?
Other landscape site?
Estimation of C and water fluxes
Forest structure changes monitoring with VHR imagery
Programm ORFEO/CNES
► mapping the 24th January 2009 windfall damages: First results
C.ORNY12, N.CHEHATA1, S.BOUKIR2, D.GUYON1, 2009
1 EGID-Université Bordeaux3, 2 INRA
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Before the storm: 22/12/2008 After the storm: 04/02/2009
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Radiometric features extraction :- Textural- Temporal change- Vegetation indices.
Segmentation -> areas with same changes
unsupervised classificationautomatical binary
classification
before and after storm
Methodology – overall framefrom algorithms in Orfeo Tool Box (CNES) / mean shift algorithm
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Satisfactory results: Unsupervised classification concentrated damages (MMU)
Errors :
No detection of damages in young stands
Difficult for plot edge (shadows and class limits)
false détection due to shadows moving To be estimated for diffuse damages
intact
damaged
1 km
Confusion matrix :
Results: binary map of damages and validation
Ground level
sate
llit
e le
vel
MMU = 5 pixels = 300m² ->5 to 45 trees according to density