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

Daily MODIS V006 BRDF, Albedo, NBAR Status 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

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    …      …      …  … … …

… …

7

Updates: Number of input observations

▸  V005: The first 4 layers

▸  V006: All the available layers

Tile h16v01 Number of observations DOY 240 8

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

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).

11

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

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

Spatial Representativeness Harvard Forest

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 Anisotropy Lidar Validation Efforts

Alan Strahler