PHAVEOS - the PHenology And Vegetation EO Service. - PowerPoint PPT Presentation
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PHAVEOS - the PHenology And Vegetation EO Service.
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PHAVEOS - the PHenology And Vegetation EO Service. Lankester, T., Dash, J.1, Baret, F.2, Koetz, B.3 & Hubbard, S. Presented by: Thomas Lankester – PowerPoint PPT presentation
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Title: PHAVEOS - the PHenology And Vegetation EO Service.
1
PHAVEOS - the PHenology And Vegetation EO
Service.
Lankester, T., Dash, J.1, Baret, F.2, Koetz, B.3
Hubbard, S.
Presented by Thomas Lankester 18th June 2010
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Objectives
- Provide time series of a range of vegetation
parameters, utilising the unique spectral,
spatial and temporal resolution of the MERIS
instrument - Make spatially and temporally continuous time
series available through visualisation and
download of maps and phenology curves for
individual locations - Support the development of a validated baseline
time series (2005 - ) in advance of the launch of
Sentinels 2 and 3
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Level 1b to Level 3 processing approach
- Convert MERIS Level 1b data to Level 3 gridded
maps, on a daily basis - geometric correction
- radiometric correction
- atmospheric correction
- derive biophysical variable(s)
- resample direct to target map grid (latlong,
OSGB36, Irish Grid)
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Level 1b geometric accuracy issues
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Level 1b geometric accuracy issues
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Level 3 geometric accuracy
- To preserve geometric fidelity, resampling into
the target map grid is carried out in a single
step
- To conserve the scene statistics area weighted
(flux-conserving) resampling is used
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Level 4 processing - interpolation
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Level 4 processing - smoothing
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Level 4 processing interpolation metrics
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Level 4 processing smoothing metric
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Level 3 validation
- Moving from Stage 1 to Stage 2() validation
requires considerable product generation - PHAVEOS is utilising the ESA Grid Processing
On-Demand (G-POD) environment - Based on MERIS FRS data from 2005 present, will
deliver a range of Level 3 and Level 4 time
series - LAI, fAPAR, fCover, MTCI, NDVI, 2G_RBi, .
- Provision of Level 3 products for MODIS match up
sites (N. America) - Coverage of PAR_at_METER sites
- OnLine Interactive Validation Exercise (OLIVE)
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Level 4 validation
- Land Surface Phenology product validation methods
TBD. - issues of spatial disparity where Sentinel 2
could bridge the gap. - Access to Forestry Commission intense monitoring
sites (leaf litter collections, phenocams) - Access to UK Phenology Network
- Access to tropical (DRC) deforestation ground
truth
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Web Map Service dissemination concept
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Phenology metrics what is the point?
- Why use, and validate / inter-compare, basic
phenology statistics? - Loss of information from a continuous time series
(are we hiding intra-annular information) - Why inter-compare on a handful of measures when
full time series are available? - Extraction of metrics is sensitive to interaction
of smoothing and metric extraction methods - Different users are interested in different
aspects of time series (phenology curves) - Are simple metrics capturing a relevant reality?
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Phenological beauty is in the eye of the beholder
Any questions
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