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Daily MODIS V006 BRDF, Albedo, NBAR Status and Updates. Zhuosen Wang, Crystal Schaaf, Qingsong Sun, Yan Liu, Alan Strahler University of Massachusetts Boston, Boston University, NASA/GSFC And the large contingent of colleagues who have contributed to the development and validation of MCD43.
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Daily MODIS V006 BRDF, Albedo, NBARStatus and Updates Zhuosen Wang, Crystal Schaaf, Qingsong Sun, Yan Liu, Alan Strahler University of Massachusetts Boston, Boston University, NASA/GSFC And the large contingent of colleagues who have contributed to the development and validation of MCD43
Daily MODIS V006 BRDF, Albedo, NBARStatus and Updates • MCD43A • Albedo (ECV), NBAR (phenology, landcover, biomass, clear-sky), BRDF (anisotropy, structure, clumping) etc.
Daily MODIS V006 BRDF, Albedo, NBAR • DAILY MCD43A • Was originally proposed as a daily product • Retrieved each day utilizing all high-quality, multi-date, multi-angle, cloud-free surface reflectances from a rolling 16-day period • Day of interest is center date • Fit semi-empirical Ross Thick Lis Sparce Reciprocal BRDF Model • Number of angularly well distributed obs (RMSE, WoD) • Weighted by quality, obscov, vicinity to day of interest • Produced in 10˚ tiles on a 500m sinusoidal grid
Daily MODIS V006 BRDF, Albedo, NBAR • DAILY MCD43A • Extensive Quality flags • Byte, not bit packed (mostly - dates used) • Snow albedo retrieval (utilizing MO/YD10) • Conservative high quality full inversion retrievals • Poor quality back up magnitude inversion algorithm uses more recent high quality retrieval as a priori BRDF shape • USE the QA!!
Daily MODIS V006 BRDF, Albedo, NBAR • Daily CMG BRDF, Albedo, NBAR (MCD43D) • 30arc-second global • Separate full retrieval • Uncertainty measures • MCD43C (0.05 degree CMG) is average of underlying parameters • Quality based on majority of underlying qualities • MCD43_GF 30arc-second snow-free, gap-filled global CMG • V005 version is available
Red 0-0.3 Blue 0-0.3 Green 0-0.3 V006 True color NBAR DOY 201, 2003 V006 Shortwave WSA DOY 201, 2003
MCD43 Collection V006 Eight Day -> Daily Collection V005 eight day product oldest Dynamic observation stream newest day 1, day 2 ... day 9, … day 16, day xxx … day 24 , day 25 … day xxx+15 … … … … … Collection V006 daily product oldest Dynamic observation stream newest day -8, day -7…DOI…, day 8, day xxx … day 16 , day 17 … day xxx+15 … … … … … … Observation weights Temporal, observation coverage, band quality
Updates: Number of input observations • V005: The first 4 layers • V006: All the available layers Tile h16v01 Number of observations DOY 240
Extensive Validation • CEOS/WGCV/Land Product Validation • BSRN (gold standard of tower albedo measurements) • Ameriflux, Surfrad, NEON, ARM, Fluxnet etc. • Spatial representativeness of sites (Román et al., 2009) • Multi-angle Airborne measurement (CAR, GLiHT etc) • Lidar Measurements of Structure (DWEL, CBL, Airborne)
Validate MODIS/Landsat albedo using CAR In general, the satellite derived estimates meet the accuracy requirements established for the high-quality MODIS operational albedos at 500 m (the greater of 0.02 units or ±10% of surface measured values). Román et al., IEEE Transactions on Geoscience and Remote Sensing,2013
Validation Sites CCP: Canadian Carbon Program IMECC: Infrastructure for Measurements of the European Carbon Cycle
Validation Results * RMSE during fully snow covered period
Validation Efforts Daily V006 NBAR (500m MCD43A4) data for tile h12v04 on 5 Aug 2007 (DOY 2007217). Harvard Experimental Forest Petersham MA
V006 NBAR (500m MCD43A4) data for tile h12v02 on 6 Sep 2009 (DOY 2009249) over the Imnaviat, Alaska Flux Site
Gap-filled Snow-free MODIS Albedo V005 White-sky Albedo DOY 193 2010 RGB
Gap-filled Snow-added-back-in MODIS Albedo White-sky Albedo DOY 289 2010
Gap-filled Snow-free MODIS Albedo Quality V005 White-sky Albedo DOY 193 2010 QUALITY!!!!!!!!
Surface Structure and AnisotropyLidar Validation Efforts Alan Strahler