Terrestrial Ecology and Land Cover/Change Science Review: Basis of Successful Land Product Validation Jeffrey L. Privette NASA’s Goddard Space Flight Center Warren Cohen, John Dwyer, S. Tom Gower, Simon Hook, Chris Justice, Alfredo Huete, Jeff Morisette, Ranga Myneni, Dick Olson, Steve Running, David Starr
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Terrestrial Ecology and Land Cover/Change Science Review: Basis of Successful Land Product Validation Jeffrey L. Privette NASA’s Goddard Space Flight Center.
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Terrestrial Ecology and Land Cover/Change Science Review:
Basis of Successful Land Product Validation
Jeffrey L. PrivetteNASA’s Goddard Space Flight Center
Warren Cohen, John Dwyer, S. Tom Gower, Simon Hook, Chris Justice, Alfredo Huete, Jeff Morisette, Ranga Myneni, Dick Olson, Steve Running,
David Starr
Challenge
One of the five primary objectives of the Earth Science Enterprise:
Identify and measure the primary causes of change
Impossible to accomplish without knowledge of measurement uncertainties
No precedent for global validation of land products
What We Knew Going In…
Excellent knowledge of point issuesLimited knowledge of site (25 km2) issues
spatial and temporal sampling scaling of point measurements error budgeting
Poor knowledge of global sampling issues except inherently cost-prohibitive without strategic planning
EOS Response
EOS Validation Program Office/D. Starr
Guidance from Instrument Teams Priorities (e.g., low level products first)
Approaches
Community resources
1997 NRA for EOS Validation Investigators Shared responsibility with product developers
Strategic Plan 1:Focus Sites
EOS Land Validation Core Sites Facilitate resource sharing and synergies in validating multiple sensors and products
Built on existing stations, resources, experts• FLUXNET, AERONET, LTER, etc.
• Long-term duration
Stratified by “6 biomes” of Myneni/Running
Jointly nominated by Instrument and (newly selected) Validation PIs
EOS Land Validation Core Sites
Solutions Data “stockpiles” for EOS Core Sites
• Unique online ftp directories at EROS Data Center 200 km x 200 km MODLAND product subsets Landsat 7 ETM+ scenes (coordinated by MODLAND)
• SeaWiFS, ASTER, UMD/CRESS, others joined
Centralized field data registry• WWW metadata catalog and data linking at ORNL• Field investigator upkeep and control of native data• Accommodates 6-month public release policy for
EOS Validation Investigators
Strategic Plan 2:Simple, Fast Data Provision
/1999 /2000 /2001
EOS Land Product Validation FTP Server
/GLCTS /Landsat7
/”site name”
/Geocover /MODIS /ASTER
/”site name”/”site name”
Level-0RLevel-1G
MOD09A1MOD13A2MOD43B3
AST_L1B
• Accessible from Land Validation Web Site or ORNL DAAC Mercury
Committee on Earth Observing Satellites (CEOS)Composed of the world’s space agencies Coordinates civilian observations from spaceWorking Group for Calibration and Validation (WGCV)
Facilitates and encourages standards, efficiencies, best practices Four Subgroups
No mechanism for coordinating or advancing validation of higher level land products
Calibrationemphasis
Strategic Plan 3:International Buy-in
Committee on Earth Observing Satellites (CEOS)Composed of the world’s space agencies Coordinates civilian observations from spaceWorking Group for Calibration and Validation (WGCV)
Facilitates and encourages standards, efficiencies, best practices Five Subgroups
Synthetic Aperture Radar Microwave Sensors Infrared and Visible Optical Sensors (IVOS) Terrain Mapping Land Product Validation
Calibrationemphasis
WGCV Subgroup onLand Product Validation
Chartered in 2000 with strong NASA advocacy
Founding focus: Support of Global Observations of Forest Cover (GOFC/GOLD) needs (fire, land cover and biophysical products)
Multinational endorsement and participationparticularly from Europe and Japan (ENVISAT, ADEOS2/GLI/ POLDER2)
Case Study 1: ASTER/Hook
MODIS and ASTER thermal infrared systems and products
ApproachVerification of sensor calibration at simple sites
Determination of lower- to higher level product uncertainties at realistic sites
Data from ground, aircraft, other sensor and lunar looks
Sites: 6 in U.S., 3 in Australia
MkIV Raft with Radiometer, Meteorological Station and Temperature Loggers
% Radiance Difference between Vicarious and OBC DerivedRadiances, v1.0.2 (1-7) and v2.05 (8-10) ((V-O)/V)*100
-2.00
-1.50
-1.00
-0.50
0.00
0.50
1.00
1.50
2.00
1(03/12/00)
2(06/24/00)
3(08/04/00)
4(08/19/00)
5(09/28/00)
6(11/07/00)
7(03/16/01)
8(06/03/01)
9(07/22/01)
10(08/22/01)
Overpass Date
Band 10 (8.29 um)
Band 11 (8.63 um)
Band 12 (9.08 um)
Band 13 (10.66 um)
Band 14 (11.29 um)
ASTER Spectral Calibration Accuracy with Time
Case Study II:BigFoot/FLUXNET
BigFoot: Site-based Sampling and Modeling Methodology
BigFoot: Site-based Sampling and Modeling Methodology
Ecosystem models are used to relate flux measurements
to MODIS derived products
VALIDATION
Based on Nemani/2/28/00
FLUXNET Validation Web Site:http://daac.ornl.gov/FLUXNET/data.html
FLUXNET Validation Web Site:http://daac.ornl.gov/FLUXNET/data.html
Online Access to FLUXNET Data
Case Study III:LAI Network/Myneni
Joint activity of CEOS LPV & MODLAND
MODIS LAI and FPAR
Open-invitation workshops from 1998- to 2000. Findings:
Several foreign groups sampling LAI, some addressing scaling
Strong interest in cross-comparisons, technical exchange and trouble-shooting
Regional networks could be developed for MODLAND LAI validation needs
Majura ValleyMajura Valley KioloaKioloa
Moreton BayMoreton Bay
Lake GeorgeLake George
Batt ReefBatt ReefCooper CreekCooper Creek
MossmanMossmanDaintreeDaintree
Cape TribulationCape Tribulation
Townsville ReefTownsville Reef
Lake ArgyleLake Argyle
GoldsworthyGoldsworthy
Lake Eyre Lake Eyre
Mt FittonMt Fitton
UardryUardry
Tinga tinganaTinga tingana
Tanjil BrenTanjil Bren
AmburlaAmburla
Port HedlandPort Hedland
KakaduKakadu
PanoramaPanorama
Hyperion SitesHyperion Sites
Other CSIRO SitesOther CSIRO Sites
KeyKeyToolabinToolabin
KunothKunoth
X band sitesX band sites
ThangooThangoo
Lake FromeLake Frome
CIGSN SitesCIGSN Sites
Endevour ReefEndevour Reef
Ray MertonRay Merton
Earth Observation Earth Observation CentreCentre
http://www.eoc.csiro.au
LAI Product Evaluation
12-18 month pathfinder
Leverage existing 2000-2001 field campaigns
Workshop: Rome, June 2001
MODLAND coordinating Landsat ETM+ acquisitions and MODLAND LAI subsets
LAI Product Evaluation: Participating Sites
Site Country BiomeBarton Bendish UK CroplandBondville IN, USA CroplandBOREAS NSA Canada Conif. ForestBOREAS SSA Canada Conif. ForestBrasschaat (De Inslag) BelgiumHarvard Forest MA, USA Decid. ForestJrvselja Estonia Boreal ForestKejimkujik Park, Nova Scotia Canada Decid. ForestKonza KS, USA GrasslandKrasnoyarsk Russia Boreal ForestLandes France Conif. ForestMali Mali ShrublandMaun Botswana WoodlandMongu Zambia WoodlandOkwa River Botswana ShrublandPandamentanga Botswana WoodlandPark Falls WI, USA Decid. ForestPodkamennaya Russia Boreal ForestRomilly France CroplandRuokolahti Finland Conif. ForestSkukuza S. Africa SavannaTshane Botswana SavannaWatson Lake, Yukon Canada Conif. Forest
Validation… What Works?
Dedicated science team liaisons for validationSimplified data access (dedicated archives) Strong communication between Product PIs and Validation PIs
Algorithm or product familiarity
Strong attention to error budgetingSatellite constellationsInternational partnerships and coordinationNetworks, networks, networks
Duration (mission succession), consistency
Validation… To Be Resolved
Global RepresentivityHow many points in time, space and biome?
ScalingInfancy for many products
Communication of ResultsFormal venues lacking
User InputBetter knowledge = greater cost How much is enough?
Uncertainty EmbeddingProduct data layer with pixel-by-pixel uncertainties
“Under-represented” Climate Combinations for North America and Asia
EOS underscored two relevant lessons:Sensor characteristics change throughout their lifetimes, including prelaunchAlgorithms change throughout their lifetimes
• Reprocessing happens.
Throughout NPP/NPOESS era (present to ~2020), NASA is purchasing products from industry
Is NASA ready to conduct performance verification?Could NASA credibly challenge a vendor on an underperforming high level product?
Permanent NASA Office on Calibration and Validation
Status of ASTER Data ProductsProduct Name Date of
Latest Upgrade
Current Release
State
Upgrade Schedule
Level 1a 28 Apr '01 ValidatedLevel 1b (AST03) 28 Apr '01 ValidatedDecorrelation Stretch (AST06) 19 Jun '01 ValidatedBrightness Temperature (AST04) 12 Jun '01 ValidatedSurface Reflectance (AST07) 24 Jan '01 Provisional Nov '01 (V)Surface Radiance VNIR, SWIR (AST09) 24 Jan '01 Provisional Nov '01 (V)
Surface Radiance TIR (AST09) 28 Mar '01 Provisional Nov '01 (V)Surface Kinetic Temperature (AST08) 09 Apr '01 Beta Nov '01 (P)
Feb '02 (V)Surface Emissivity (AST05) 09 Apr '01 Beta Nov '01 (P)
Feb '02 (V)Digital Elevation Model (DEM) (AST04) absolute