A focused activity
of the CEOS WGCV
Land Product Validation (LPV) Subgroup
LAI Intercomparison sites
LPV participants have recommended several activities deserving immediate attention. One prominent need is an intercomparison of research and operational LAI products, together with an assessment and development of standards for field LAI measurements and scaling.Toward this need, field data collectors have agreed to share their data sets collected in 2000 (and beyond) for this purpose. An October, 2000, survey revealed that field data from at least 22 sites were available. Further, remote sensing data from at least 10 different sensors had been collected in association with the field efforts. These data serve as the basis for the intercomparison.
To date, most investigators have worked
exclusively on their own data sets. Now, through this activity we are providing web-based access to the image and field data for participating sites.
Link to data and information for a site:
Background Information
Initial meeting,
hosted by ESA, Frascati, Italy
June 7-8, 2001
The initial step for this activity was a workshop
held in June, 2001. This provided an opportunity to share insights
and evaluate progress on LAI product validation and place this work in
the context of the Global Observation of Forest Cover (GOFC)
program. Based on the discussion and presentations at the meeting,
the LPV subgroup is preparing a report outlining best-practice strategies
for validating satellite-derived LAI products. This report will be displayed
on the LPV WWW site upon completion and submitted for publication in a
peer review journal.
This meeting is reported in The Earth Observer article
"Summary of the International Workshop on LAI Product Validation")
Agenda:
Presentations from the meeting are linked below.Any reference or duplication of the materials should be confirmed with the author(s) of the material.
Day one, June 7
1330 Welcome (Desnos/Privette)
1345 Charge (Privette)
1400 Status of LAI Products from Current/Future SystemsRate Current Product Performance Draft Field Method and Analysis Protocol
(Including GCM LAI Products from NDVI)
(20 min. ea., Privette chairing)
- MODIS (Myneni)
- AVHRR (Los)
- LAI production from POLDER (Leroy)
- Biophysical products from MERIS (Pinty) (related bibliography)
- CCRS Perspective on LAI Products from Current/Future Systems (Fernandez)
1615 LPV Staff Activity in Support of LAI Intercomparison: Status (Morisette)
- Participating Site Catalog
- MODIS LAI distribution
(interactive drafting of performance matrix: biome vs. sensor, initial assessment)
(20 min ea.; Morisette chairing)
- SAVE (Privette)
- Validation of biophysical products from large swath sensors: VALERI (Baret)
- Canada LAI Network: algorithm & validation (Fernandez)
- BigFoot (Gower)
- Belgium (Verastroute, document submitted)
- Krasnoyarsk (Conley/Deering, submitted material)
- LAI Measurement Protocols and Scaling (Chen)
- Airborne Vegetation Canopy Lidar - Australian Developments (Barton)
1900 Adjourn
Related information not presented at the
meeting:
Leaf
Area Index (LAI): a historical field data set for global vegetation modeling
and remote sensing validation
Jonathan Scurlock and Dick Olson
Day 2, June 8
0830 Satellite LAI cross-comparisons
and Fine Resolution LAI products in support of med. res. Products
- Multiple satellite product comparison (Morisette)
- SPOT data in support of land product validation activities (tentative: Hervé Jeanjean)
0900 Developing an LAI Validation protocol
- Indirect methods to characterize LAI from ground measurements (Weiss/Baret)
- protocol considerations (group, led by Privette/Baret)
- land cover type
- heterogeneity/clumping
- objective/required accuracy
- field instrument
- sample design in space and time
1300 Lunch
1430 Other Business (Privette, Morisette)
- Publication of global, site-based LAI evaluation (20 min)
- Data Reanalysis/ use of common data set (15 min)
- Moving from qualitative evaluation to quantitative (40 min)
- Formalization and release/publication of LPV protocols and caveats (20 min)
1600 Future GOFC-LPV Coordination and
Support (TBD)
1645 Next Meeting, Path Forward (all)
1700 Adjourn
Action items:
- Presenters to provide electronic copy and any related bibliography to Morisette
- Morisette to post presentations on LAI inter-comparison page
- Baret to prepare summary of Friday a.m. discussion, and forward to Morisette
- Privette, Morisette, Weiss and Baret to prepare Earth Observer article and ESA EO quarterly
- Gower to start outline for LAI validation guideline article (author=“LPV”, contributing authors listed in table alphabetically), deadline: before CEOS plenary, November 2001
- Morisette to keep group informed on the outcome of CEOS Land Validation Core Sites (intend to submit proposal to WGISS during the week of June 18th)
- Myneni/BU to provide “user support” for MODIS LAI product-subset tool, et al.
- VALERI, BigFoot, CCRS to provide access to high-res LAI maps or field data
- Gower, Privette, Morisette to revisit global representation–fill gaps
- Privette to write GOFC and/or TCO, requesting delegate on LPV (Baret)
