daily modis v006 brdf, albedo, nbar status and updates zhuosen wang, crystal schaaf, qingsong sun,...

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

MCD43AAlbedo (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 0-0.3Blue 0-0.3Green 0-0.3

V006 True color NBAR DOY 201, 2003

V006 Shortwave WSADOY 201, 2003

MCD43 Collection V006 Eight Day -> Daily

Observation weights Temporal, observation coverage, band quality

oldest Dynamic observation stream newest

day 1, day 2 ... day 9, … day 16, day xxx … day 24 , day 25 … day xxx+15 … … …

Collection V005 eight day product

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 … … …… ……

… …

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 TypeFlux 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 AmeriFluxSK-1989 Fire 54.254 -105.878 h11v03 Mixed Forests CCP

Bily Kriz- Beskidy Mountains 49.502 18.537 h19v04 Mixed Forests IMECCHainich 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 IMECCSkukuza -25.020 31.497 h20v11 Savannas CarboAfricaEl Saler-Sueca 39.276 -0.315 h17v05 Croplands IMECCLangerak 52.004 4.806 h18v03 Croplands IMECCDripsey 51.987 -8.752 h17v03 Grasslands IMECCFort Peck 48.308 -105.102 h11v04 Grasslands SURFRADBoulder 40.050 -105.010 h09v04 Grasslands BSRNCottonwood 43.950 -101.847 h10v04 Grasslands AmeriFluxBarrow 71.323 -156.609 h12v01 Tundra BSRNImnaviat 68.613 -149.312 h12v02 Tundra LTERDesert Rock 36.620 -116.020 h08v05 Desert SURFRAD

IMECC:Infrastructure for Measurements of the European Carbon Cycle

CCP:Canadian Carbon Program

Validation Sites

Mixed ForestNeedleleaf

ForestBroadleaf

ForestSavanna/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/A0.0634

(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 AnisotropyLidar Validation Efforts

Alan Strahler