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EPA MODIS LAI Evaluation Activities in the Albemarle-Pamlico Basin, NC/VA

This workshop outlines the EPA's MODIS LAI project, including field studies, results, and data sets for archiving remotely sensed data. It also discusses potential applications of MODIS LAI at EPA.

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EPA MODIS LAI Evaluation Activities in the Albemarle-Pamlico Basin, NC/VA

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  1. Drew Pilant, Ph.D. Timothy Lewis, Ph.D., John Iiames, Mark Murphy (US EPA) Jayantha Ediriwickrema, Ph.D. (Computer Sciences Corporation) MODIS Vegetation Workshop II, Missoula MT August 16, 2004 EPA MODIS LAI Evaluation Activities in the Albemarle-Pamlico Basin, NC/VA

  2. Outline • EPA LAI project at a glance • Applications of MODIS LAI at EPA • Describe field studies • Results and observations • Data sets for archiving

  3. Remotely Sensed Data: • MODIS LAI (MOD15A2) 8 day time series • MODIS NDVI (MOD13Q1) 16 day time series • Landsat ETM+ time series (2-8 images/site) • 4 IKONOS XS scenes • Digital Elevation Model • Field Measurements at Multiyear Study Sites, 2001-2004: • TRAC sunfleck profiling • Hemispherical photography • Baseline forest biometrics • Ground and canopy photos for each site visited LAI Project at a Glance

  4. Potential Applications of MODIS LAI (MOD15A2) at US EPA • Biogenic emissions models (BEIS2) • Air quality models (CMAQ) • Atmospheric deposition models • Landscape characterization and monitoring • Vegetation phenology in land cover mapping and change detection

  5. LAI Field Studies Iiames, J.S., A.N. Pilant, T.E. Lewis. 2004. In-situ estimates of forest LAI for MODIS data validation. in: Lunetta, R. and J. Lyon (eds.), Remote Sensing and GIS Accuracy Assessment, CRC Press, Boca Raton, FL.

  6. EPA RTP Long term field sites: Study Area: Albemarle-Pamlico Basin, NC/VA EPA Research Lab At Research Triangle Park, NC

  7. Hemiphoto: Optical Measurements of In Situ LAI Hemispherical photography Upward looking Dawn/dusk/overcast days

  8. TRAC: Optical Measurements of In Situ LAI Sunfleck profiling: TRAC (Tracing Radiation and Architecture of Canopies) Full sun/mid-day

  9. Real time differential GPS geolocation for grids/transects

  10. 8/6/2002 7/29/2002 Baseline Forest Biometrics Species distributions Tube densiometer Photo time series 0o 45o Grid stake

  11. Canopy gap PPFD (light intensity) 50 m Field LAI Sampling Grids and Transects 100 m 100 m

  12. Quadrants 100x100 m Subplots Two 50 m lines Fairystone, VA site: montane province Scaling: Field Transects to Landsat ETM+ Landsat ETM+ image 30 m pixels Quadrants and subplots inside hypothetical 1 km MODIS LAI pixel

  13. LAI Scaling: Field to MODIS

  14. Results and Observations • LAI phenology shows green-up • Understory removal effects on NDVI • MODIS NDVI in LAI backup algorithm • Field data: MODIS LAI direct comparison

  15. 1 2 3 4 MODIS LAI Time Series in Albemarle-Pamlico Basin

  16. Understory Removal in 100x100 m plot: Effect on IKONOS NDVI Before understory cut After understory cut Iiames, J. S., Pilant A.N. , Lewis T. Congalton R. Leaf Area Index (LAI) change detection on loblolly pine forest stands with complete understory removal,   Proc. ASPRS 2004 Annual Conference, 05/23/04, Denver, CO.

  17. 0523_2002 0803_2002 Understory Removal in 100x100 m plot: Effect on IKONOS NDVI IKONOS NDVI image Before understory cut After understory cut Understory removal: 3% NDVI reduction (p<0.05) Iiames, J. S., Pilant A.N. , Lewis T. Congalton R. Leaf Area Index (LAI) change detection on loblolly pine forest stands with complete understory removal,   Proc. ASPRS 2004 Annual Conference, 05/23/04, Denver, CO.

  18. Failure RT Algorithm (Backup) Success RT Algorithm MOD15A2: Radiative Transfer vs NDVI Algorithm5x5 km (25 pixels) sample • Begin your presentation here

  19. Version 4 Version 3 MODIS NDVI: Data Challenges

  20. MODIS LAI spectral profiles from 5 adjacent pixels LAI * 10 + + + Jan Feb Mar Apr May Jun Jul Aug Sep + = in situhemispherical photoLAI MODIS and Hemiphoto LAI Time Series at Fairystone Site (deciduous)

  21. MODIS and TRAC LAI Time Series at Appomattox Site (pine) MODIS LAI spectral profiles from 5 adjacent pixels + + LAI * 10 + + Jan Feb Mar Apr May Jun Jul Aug Sep + = in situTRACLAI

  22. LAI Field Data Sets for Archiving

  23. LAI Image Data Sets for Archiving

  24. Ongoing work • Validation of TRAC and Hemiphoto methods • Comparison with destructive harvest at NCSU sites • TRAC/Hemiphoto repeatability measurements • Develop 500-1000 m TRAC transect method • Methods for scaling • Field: Landsat ETM:MODIS • Organize / QA Data Archiving

  25. Begin your presentation here Thank you! Acknowledgments: NASA State of VA State of NC NCSU Duke University Westvaco International Paper pilant.drew@epa.gov

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