Land Product Validation

Transcription

1 CEOS WGCV Land Product Validation Sub-Group Joanne Nightingale 1, Jaime Nickeson 1 & Gabriela Schaepman-Strub 2 ( 1 Sigma Space Corp / NASA GSFC, 2 University of Zurich) ~ With input from LPV Focus Group Leads

2 Outline Objectives and Goals LPV Structure Role in GEOSS LPV activities per Focus Area 2

3 LPV Objective & Goals To foster and coordinate quantitative validationof higher level global land products derived from remotely sensed data, in a traceable way, and to relay results so they are relevant to users To increase the quality and efficiency of global satellite product validation by developing and promoting international standards andprotocolsfor: Field sampling Scaling techniques Accuracy reporting Data / information exchange To provide feedback to international structures (GEOSS) for: Requirements on product accuracy and quality assurance (QA4EO) Terrestrial ECV measurement standards Definitions for future missions 3

4 LPV Sub-group Structure Chair:Joanne Nightingale (NASA GSFC) Vice-Chair: (University of Zurich) Support: (NASA GSFC) Gabriela Schaepman-Strub Jaime Nickeson 8 Land Product Focus Groups 2 international co-leads 4

5 Focus Groups * ECV 5

6 Role of LPV Focus Groups Engage community members (via listserv/website) Periodic updates sent to mailing lists Meeting announcements on website Organize at least 1 topical workshop within leadership term Land Cover June 2011 LAI/fPAR OLIVE Feb 2012 Phenology, LAI protocol workshop September 2012 Expand LPV activities, field sites, collaborationglobally Lead / Guide the development and writing of best practice land product validation protocols Guide / Lead product inter-comparison activities Define product error definitions for ECV s / LTDR s for the climate modeling community 6

7 LPV Webpage Background Products Subscribe to a focus area! Meetings Case Studies Inter comparisons 7

8 LPV Involvement in GEO Ensuring land validation community needs are addressed by GXOS CEOS response to GCOS IP 138 action items / 12 relate directly to land validation: (data quality, inter-comparison, collection of in-situ data) Providing recommendations to IGBP Integrated Observing Strategy & IPCC Assessments Coordination between ground / space based observations Providing input to CEOS ECV inventory (WG Climate) Advising new satellite missions and projects on land product validation planning e.g. NASA Decadal Survey HyspIRI, SMAP ESA Climate Change Initiative 8

9 LPV and Data Quality LPV involvement with GEO QA4EO, WGCV WGISS and ESIP Federation Information Quality Cluster (GSFC) Quality Information Standards for ALL remote sensing products : Metadata QA flags Assessment of fitness for purpose and ways of defining this within product meta-data Needs to be conducted on a product-by-product basis 9

10 Land Product Protocols Best practice for land product validation Current: knowledge, data, tools & methods Peer-reviewed CEOS endorsed/published Key for ECV product validation Draft validation protocols: Leaf Area Index Land cover area change (via GOFC-GOLD) Burned Area (via GOFC-Fire) Status of these provided within focus area status updates 10

11 Land Product Inter-comparison Many sensors - similar products Evaluation of spatial & temporal consistency between products Indirect product assessment Highlights regions/temporal periods where detailed direct validation studies are warranted LAI product inter-comparison Investigated the performance of 4 global LAI products at ~10km sampling / monthly time step GCOS recommendation to conduct LAI product inter-comparison at a finer spatial resolution ~1km 11

12 Focus Group Reports Key activities related to GCOS IP action items recommending validation Planned activities / meetings 12

13 Land Cover Focus Group GCOS Action T27 [IP-04 T26] Action: Generate annual products documenting global land-cover characteristics and dynamics at resolutions between 250 m and 1 km, according to internationally-agreed standards and accompanied by statistical descriptions of their accuracy. GCOS Action T28 [IP-04 T27] Action: Generate maps documenting global land cover based on continuous m land surface imagery every 5 years, according to internationallyagreed standards and accompanied by statistical descriptions of their accuracy. 13

14 Land Cover Focus Group Land cover product validation activities continuous, active process, spanning multiple projects, several decades GOFC-GOLD land cover project office serves as focal point for coordination of International community in the development of global and regional validation datasets and best practice protocols Implement / support global land cover validation efforts: Product development and enhancement: GLC2000, GLOBCOVER New approaches driven by ECV requirements (i.e. ESA land cover CCI) In situ measurements and sampling designs: JRC/FAO FRA and BU global systematic sampling & stratified random design independent of existing datasets Product comparison and move to synergy among existing global datasets Based on quantitative information of uncertainties 14

15 Land Cover Focus Group Global sample design and database for LC validation independent of specific products Design provides a global stratified sample of 500 LC validation sites based on climate/vegetation biomes & population data, sample sites are 5km x 5km Ground truth derived from very high resolution imagery with the assistance of local experts Global Validation Sites: Stratification & Geographic Sampling 15

16 Land Cover Focus Group 16

17 Fire Focus Group GCOS Action T36 [IP-04 T33] Action: Continue generation of consistent burnt area, active fire, and FRP products from low orbit satellites, including version inter-comparisons to allow unbiased, long-term record development. GCOS Action T37 [IP-04 T34] Action: Develop and apply validation protocol to fire disturbance data. 17

18 Fire Focus Group Activities being coordinated with US- and EU/ESA-led projects and GOFC- GOLD Fire IT GEOLAND2 ESA CCI MODIS Active Fire and Burned Area products VIIRS Validation of burned area products was discussed at length at 2 significant workshops in late 2011: ESA CCI project Round-Robin workshop: The Fire CCI project, funded under the Climate Change Initiative of the European Space Agency, aims to generate consistent and accurate global burned area (BA) information for climate-vegetation modellers BA product validation plan has been created and is currently in review with ESA. GOFC-GOLD Fire workshop: Focussed on discussion of GCOS IP templates for BA product validation requirements in the coming 10 years 18

19 Fire Focus Group Work is finally underway for the generation of a CEOS Stage 3 burned area validation dataset References datasets primarily consist of Landsat Pairs Burned Area Validation Protocol - stillin progress The theoretical work / documentation will be completed by June 2012, and the dataset will be ready by the end of the year 19

20 Biophysical Focus Group GCOS Action T29 [IP-04 T29] Action: Establish a calibration/validation network of in situ reference sites for FAPAR and LAI and conduct systematic, comprehensive evaluation campaigns to understand and resolve differences between the products and increase their accuracy. [IP-10 Action T3] Develop a subset of current LTER and FLUXNET sites into a global terrestrial reference network for monitoring sites, with sustained funding perspective and co-located measurements of meteorological ECVs GCOS Action T30 [IP-04 T30] Action:Evaluate the various LAI satellite products and benchmark them against in situ measurements to arrive at an agreed operational product. 20

21 Biophysical Focus Group LAI Validation Protocol Initial meeting, draft outline March 2009 Full draft complete and sent for community review February 2012 Defines internationally accepted definitions of LAI and associated quantities to ensure thematic compatibility Defines conversions between quantities, reviews sampling and scaling techniques, direct and indirect validation and consistency checking measures Provides 104 detailed recommendations for best practice to: CEOS agencies LAI product producers Scientific research community LAI product validation investigators 21

22 OLIVE (OnLineInteractive Validation Exercise) (Baret et al.) Web-interface tool for independent validation of biophysical land products (LAI, fapar and Albedo) Will provide existing in situ data and high resolution reference maps for validation, new validation datasets may be submitted Technical specifications document undergone review by ESA and key LPV members Operational ~

23 Surface Radiation Focus Group GCOS Action T24 [IP-04 T19] Action:Obtain, archive and make available in situ calibration/validation measurements and collocated albedo products from all space agencies generating such products; promote benchmarking activities to assess the quality and reliability of albedo products. 23

24 Surface Radiation Focus Group Activities being coordinated with US- and EU-led projects GLOBALBEDO (major data processing issues, production expected to restart in Feb 2012) GEOLAND 2 Validation report has been through review with ESA and will be available in Feb 2012 MODIS Albedo MODIS BRDF/albedo algorithm improvements based on previous validation studies (Wang et al. 2011, RSE), dataset reprocessing to begin in Fall 2012 VIIRS Albedo Successful launch of NPP in October 2011, preliminary products currently being produced and evaluated internally Albedo Validation Protocol Writing team members identified just too busy! 24

25 Surface Radiation Focus Group Evaluation of tower sites for representativeness using geo-statistical measures and high resolution imagery over various seasons ~100 sites characterized for leaf on/off Fluxnet, NEON, BSRN Assessment of representativeness for sensors beyond MODIS Establishment of more instrumented sites required 25

26 Soil Moisture Focus Group GCOS Action T13 Action:Develop a record of validated globally-gridded near-surface soil moisture from satellites. GCOS Action T14 Action:Develop Global Terrestrial Network for Soil Moisture (GTN-SM). 26

27 Soil Moisture Focus Group International Soil Moisture Network Dorigo et al EOS. Vol92 p 141 Launch first global Soil Moisture product intercomparison assessment for 2010 Only global, freely available datasets Conducted by independent party Point-wide validation, comparison with in-situ measurements (10-20 sites) and modeled surface SM data Global product inter-comparison Findings indicate that after bias correction, the SM retrieval skill of SMOS, ASCAT, AMSR-E is comparable and of good quality in regions with sparse to moderate vegetation cover Parrens et al. 2012; Albergel et al. 2012; Brocca et al. 2011) 27

28 Soil Moisture Focus Group 2012 funding available for the ESA CCI Soil Moisture product project to start some round-robin exercises for AMSR-E and ASCAT. Coordination of a Soil Moisture Master Document Meet all reporting needs related to calibration, validation, product specifications, ECV standardization etc. Lead by GEWEX with input from SMOS, SMAP Science Teams, LPV 28

29 Moving Forward LPV will continue to promote Land Validation in the GEOSS setting LPV will continue to work with IGBP, WCRP WOAP, IPCC, GCOS, GTOS, TOPC Product validation standardized measurements and methods Future validation requirements LPV Protocols Extremely important for ECV product validation Development slow funding / resources / time constraints / coordination with other international groups Global terrestrial reference network of multi-instrumented monitoring sites, with sustained funding perspective, is essential Utilize existing networks (LTER, FLUXNET, NEON, TERN) Address scaling issues Enhance spatial and temporal understanding of satellite resources for earth system monitoring Validation activities MUST be internationally coordinated and receive dedicated space agency funding 29

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