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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, NBAR Status and Updates
MCD43A Albedo (ECV), NBAR (phenology, landcover, biomass, clear-sky), BRDF (anisotropy, structure, clumping) etc.
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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
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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!!
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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
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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
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MCD43 Collection V006 Eight Day -> Daily
Observa(on weights Temporal, observa.on coverage, band quality
oldest Dynamic observa.on stream newest
day 1, day 2 ... day 9, … day 16, day xxx … day 24 , day 25 … day xxx+15 … … …
Collec(on V005 eight day product
Collec(on V006 daily product
oldest Dynamic observa.on stream newest
day -‐8, day -‐7…DOI…, day 8, day xxx … day 16 , day 17 … day xxx+15 … … … … … …
… …
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Updates: Number of input observations
▸ V005: The first 4 layers
▸ V006: All the available layers
Tile h16v01 Number of observations DOY 240 8
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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)
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Validate MODIS/Landsat albedo using CAR
Román et al., IEEE Transactions on Geoscience and Remote Sensing,2013
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).
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Site Name Lat Lon MODIS Tile Land Type Flux Networks
BC-‐Campbell River 1949 Douglas-‐fir 49.867 -‐125.334 h09v04 Evergreen Needleleaf Forest CCP
SK-‐1998 Fire 54.092 -‐106.005 h11v03 Evergreen Needleleaf Forest CCP
Wetzstein 50.454 11.458 h18v03 Evergreen Needleleaf Forest IMECC
Griffin-‐ Aberfeldy-‐Scotland 56.607 -‐3.798 h17v03 Evergreen Needleleaf Forest AmeriFlux
Tumbarumba -‐35.656 148.152 h30v12 Evergreen Broadleaf Forest OzFlux
Hesse Forest-‐ Sarrebourg 48.674 7.066 h18v04 Deciduous Broadleaf Forest IMECC
Walker Branch 35.959 -‐84.287 h11v05 Deciduous Broadleaf Forest AmeriFlux SK-‐1989 Fire 54.254 -‐105.878 h11v03 Mixed Forests CCP Bily Kriz-‐ Beskidy Mountains 49.502 18.537 h19v04 Mixed Forests IMECC Hainich 51.079 10.452 h18v03 Mixed Forests IMECC
Harvard Forest 42.538 -‐72.172 h12v04 Mixed Forest Ameriflux Las Majadas del Tietar 39.942 -‐5.773 h17v05 Closed Shrublands IMECC Skukuza -‐25.020 31.497 h20v11 Savannas CarboAfrica El Saler-‐Sueca 39.276 -‐0.315 h17v05 Croplands IMECC Langerak 52.004 4.806 h18v03 Croplands IMECC Dripsey 51.987 -‐8.752 h17v03 Grasslands IMECC Fort Peck 48.308 -‐105.102 h11v04 Grasslands SURFRAD Boulder 40.050 -‐105.010 h09v04 Grasslands BSRN Coconwood 43.950 -‐101.847 h10v04 Grasslands AmeriFlux Barrow 71.323 -‐156.609 h12v01 Tundra BSRN Imnaviat 68.613 -‐149.312 h12v02 Tundra LTER Desert Rock 36.620 -‐116.020 h08v05 Desert SURFRAD
IMECC: Infrastructure for Measurements of the European Carbon Cycle
CCP: Canadian Carbon Program
Validation Sites
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Mixed Forest Needleleaf Forest
Broadleaf Forest
Savanna/ Shrubland
Grassland/ Cropland/ Tundra Desert
All quality
Bias -‐0.0015 -‐0.0074 -‐0.0037 0.0071 0.0047 0.0028
RMSE 0.0187 0.0241 0.0162 0.0129 0.0293 0.0118
Full inversion
Bias -‐0.0005 -‐0.0067 -‐0.0025 0.0086 -‐0.0006 0.0025
RMSE 0.0152 0.016 0.0123 0.0136 0.0211 0.0108
Magnitude inversion
Bias -‐0.0025 -‐0.0079 -‐0.0052 0.0008 0.0118 0.0107
RMSE 0.0215 0.0294 0.0203 0.0096 0.0375 0.0218
Snow free
Bias -‐0.0013 -‐0.0081 -‐0.0032 0.0071 0.0033 0.0029
RMSE 0.0183 0.0189 0.0151 0.0129 0.0224 0.0117
Snow covered
Bias -‐0.0102 -‐0.0018 -‐0.0275 N/A 0.0175 N/A
RMSE 0.0274 0.0487 0.0465 N/A 0.0634
(0.0465)* N/A
* RMSE during fully snow covered period
Validation Results
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Spatial Representativeness Harvard Forest
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Validation Efforts
Daily V006 NBAR (500m MCD43A4) data for tile h12v04 on 5 Aug 2007 (DOY 2007217). Harvard Experimental Forest Petersham MA
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V006 NBAR (500m MCD43A4) data for tile h12v02 on 6 Sep 2009 (DOY 2009249) over the Imnaviat, Alaska Flux Site
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Gap-filled Snow-free MODIS Albedo V005
White-sky Albedo DOY 193 2010 RGB
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Gap-filled Snow-added-back-in MODIS Albedo
White-sky Albedo DOY 289 2010
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Gap-filled Snow-free MODIS Albedo Quality V005
White-sky Albedo DOY 193 2010 QUALITY!!!!!!!!
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Surface Structure and Anisotropy Lidar Validation Efforts
Alan Strahler