Remote Sensing data product Contribution from data providers/algorithm development team
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Transcript of Remote Sensing data product Contribution from data providers/algorithm development team
Remote Sensing data product
Contribution from data providers/algorithm development team
Data from many moderate resolution remote sensing sensor, mainly vegetation indices at a compositing period
We broadly follow three steps to derive phenological matrices• Data filtering• Temporal smoothing (many methods)• Derived matrices ( many method and many matrices)
JÖNSSON and EKLUNDH, 2004
MODIS NACP Phenology ProductsRetrieved Phenology Metrics
1. Beginning of season2. End of season3. Length of season4. Base VI value5. Peak time 6. Peak value7. Amplitude8. Left derivative9. Right derivative10. Integral over season
- absolute11. Integral over season
- scaled12. Maximum value13. Minimum value14. Mean value15. RMSE of fitting
MODIS NACP Phenology ProductsAvailability and Status
Availability: From http://accweb.nascom.nasa.gov/
Products: phenology metrics derived from LAI/EVI/NDVI, and
original, smooth/gap-filled LAI, FPAR, EVI & NDVI.
Temporal Coverage: From 2001 to 2010.
Spatial Coverage: Full North America, partially South America.
Asia is under processing.
Online data services: Subset by geographic area Subset by data layer Reproject Mosaic Aggregation Re-format (to GeoTIFF).
MCD12Q2 C5 Product• Global database
– Annual since 2001, 500-m
• Includes 7 metrics– Onset of EVI increase – Onset of EVI maximum – Onset of EVI decrease– Onset of EVI mimimum
– Min EVI
– Max EVI
– Sum of growing season EVI
• Validation:– Opportunistic, largely in New England
– Current focus on PhenoCam Data
Timing
AnnualMetrics
Mark Friedl
USGS EROS Vegetation Dynamics
Availability: From http://phenology.cr.usgs.gov//
Products: Nine annual remote sensing phenological indicators
(served as raster data sets) are available at two spatial resolutions
(1000 m2 and 250 m2) based on NDVI
Temporal Coverage: AVHRR (1989-2011)
MODIS (2001-2011)
Spatial Coverage: conterminous U.S.
Method : Delayed Moving Average (DMA) method (Reed et al.,
1994).
Considerable QA checking done on USGS phenological data
Jesslyn Brown
Phenological metrics available at multiple resolutions
Jesslyn Brown
Phenological metrics available at multiple resolutions
Jesslyn Brown
Jesslyn Brown
The “VGT4Africa” phenology product• Algorithm developed by the Joint Research Centre (European
Commission)• Product generated by VITO (Belgium)• Based on the processing of a moving time-window of 1.5 year
of NDVI from the VEGETATION instrument• Updated within 3 days after every 10-day period (“dekad”)• Covers the whole African continent• Provides dekad dates for “start of growth”, “max NDVI” and
“half-senescence”• Availability: from VITO through ftp and EUMETCast, jan 2007
until present• Product description: Combal B. & Bartholomé E. 2006: Phenology. In: Bartholomé
edit: VGT4Africa user manual 1st edition, European Commission ref EUR 22344 EN: 165-212
• Method: Combal B. & Bartholomé E. 2010: Retrieving phenological stages from low resolution Earth observation data. In: Maselli & al.: Remote Sensing Optical Observations of Vegetation Properties, Research Signpost, Kerala, India, 115-129.
Bartholomé
Bartholomé
Start dates as observed on 3rd dekad of Dec 2011(note: actual time resolution of the product is the dekad, not the month)
VIP Data Explorer:30 Years of Multi-Sensor VI and Phenology Data
Availability: From vip.arizona.edu/viplab_data_explorer.php
Products: Vegetation index and phenology from AVHRR,
VEGETATION, MODIS (Sensor independent)
Temporal Coverage: 30+
Spatial Coverage: Global
Spatial resolution : 0.05 deg
Considerable data quality assessment
Kamel Didan
Kamel Didan
PHAVEOS – the Phenology And Vegetation EO Service
A service to provide:Vegetation maps of several biophysical variables relevant
to models of bio-geochemical cycles Leaf Area Index (LAI) fraction of Absorbed Photosynthetically Active Radiation (fAPAR)
MERIS Terrestrial Chlorophyll Index (MTCI) fraction of green land cover (fCover)
Continuous time series to support phenology studies and monitoring
Visualisation of individual maps and phenology curves for individual locations
Thomas Lankester
MERIS / MODIS
Sentinel 3 Sentinel 2 (LDCM)
Biophysical processing and mapping
Data sources
HiProGen and Overland
Daily Level 3 and Level 4 data dissemination
WebServerWeb client on user PC
Level 3 daily product examples
fCover LAI fAPAR
ftp://l3-server.infoterra.co.uk/pub/SNL/MTCI_L4_2009-2010_comparison.gif
Spring 2009 – 2010 comparison
Phenology Land Product Validation WorkshopCore Site Selection
Original Sites (2010 Dublin Workshop):• Do we keep the original sites?• Are more sites needed?• What are the essential variables and is it
necessary for every site to offer the same set of core variables/instruments?
Site Name Country Cover Type Lat Lon MET FLUX Pheno CameraRadiometer
PAR Pheno ObservationsTorgnon – Tellinod Italy Grassland 45.82 7.56 X X X X XTorgnon – Tronchaney Italy Larch Forest 45.82 7.56 X X X X XPark Falls USA Deciduous Broadleaf 45.95 -90.27 X X XHyytiala Finland Boreal Conifer 61.85 24.29 X X X X XHarvard USA Mixed Forest 42.54 -72.17 X X X XBartlett USA Mixed Forest 44.06 -71.29 X X XHowland USA Boreal Hardwood Trans 45.2 -68.74 X X XTakayama Japan Deciduous Broadleaf 36.15 137.42 X X X XTakayama Japan Evergreen Coniferous 36.14 137.37 X X X XBarrax Spain Cropland 39.05 -2.09Hubbard Brook USA Deciduous Hardwood 43.93 X X X XVaira Ranch USA Grassland 38.41 -120.95 X X X X…other suggestions? particularly Asian or Southern Hemisphere locations.
Phenology Land Product Validation WorkshopPanel Discussion
Working across scales:•Are site specific nested datasets (in-situ, phenocam, RS) and validation results applicable to validation of continental/global RS phenology products?• Do PhenoCams need to be validated with in-situ observations?
What standards need to be set for Phenology LPV:•Are standardized definitions needed for metrics? – Start of Season, End of Season•Are standardized methods needed to calculate metrics? – Curve fitting, Derivative peaks, etc. •What do we mean by Phenology Validation? Is it setting a realistic offset/error range between phenocam or in-situ and RS metrics? Is this application specific?•What are best practices for LPV using in-situ data?
Phenology Land Product Validation WorkshopPilot Project Definition
Core Sites Selection and Considerations:•Do we agree upon the site selections?•Is all data freely available? Creation of formal data sharing agreement.
Data Collections/Bundles:•RS products – size of subset over each site, 100km?•Centralized Storage and Access•Ground/In Situ Site Data – centralized storage?Project Objectives:•Do we allow for a flexible structure and let researchers dictate site by site analysis OR do all projects follow a set protocol?•Timeline – What is a realistic expectation? The LPV 5yr Plan states Validation Protocol established by 2013. Responsible Parties:•Data Collections/Bundles – must be available by…?•Who will conduct the research? PhD Students, Post-Docs, Staff Scientists.
Phenology Land Product Validation WorkshopWorkshop Review
Did we meet our objectives?Provide a synopisis of the majority available data sets.Review and discuss validation methods, current limitations and concerns.Selection of Core Sites.Agreement on data subsets, storage and access.Define Pilot Projects.Set a course for future Land Surface Phenology Validation
For the future:Do responsible parties understand their tasks (providing data, analysis, etc.)Write up of a Meeting Summary Publication – EOS.Summary Poster for AGU – Jadu and Matt with input from committee.Informal Meeting at AGU 2012 to discuss progress.