The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
Date 
DOY 
Site 
BR(field) 
BR(Est) 
25-Jul 
206 
Crop 
0.324 
0.451 
28-Jul 
209 
Crop 
0.945 
0.725 
5-Aug 
217 
Crop 
0.711 
0.510 
8-Aug 
220 
Crop 
0.738 
0.691 
9-Aug 
221 
Crop 
0.466 
0.554 
25-Jul 
206 
Grass 
0.552 
0.561 
28-Jul 
209 
Grass 
0.672 
0.582 
5-Aug 
217 
Grass 
0.666 
0.676 
8-Aug 
220 
Grass 
0.739 
0.682 
9-Aug 
221 
Grass 
0.534 
0.406 
Table III. comparison of Bowen ratio in TOngyu, 2003 
Results in Table III show that BR estimated tend to be less 
variable than field data, partly caused by the spatial average. 
The H/LE patterns are good consistent with field 
data(coefficient of correlation, r=0.762), although absolute error 
in daily ET is about 20% that means error in a single day could 
reach 2mm/day at most. But for a longer term, such error will 
decline rapidly. 
4.5 Sensible heat maps 
Figure III shows results for output sensible heat components, 
briefly decomposed using fractional vegetation cover, fc. The 
gross main structure of the sensible heat flux on canopy is 
explained by the fc derived from MODIS LAI products, but 
such simplified assumption of thermodynamic temperature 
decomposed would be improper in refined resolution. 
SitiSible Ileal Flux in Ttmfcy u.Sep-10-2003 
it? it mam m is mti 
UTR tut are. i2».e m are 
Sensible Heat Mux uf $<Hl,Tu«i&yu.Sep-10-2003 
u? it MfWK taut m art mi< 
117 R 120 E 121 are 
‘iis*bk‘ Ileal Mux uf Plant Ciuop),Toog)«LScp-10-20®3 
it?« n«ar»i taut i?t*m mn 
¡i? r ttaarK i2qe i2i are 
Figure 3: (left)(center)(right),tongyu,09/10/2003 
5. CONCLUSION 
A new method to estimate surface fluxes using two-time surface 
temperature measurement is presented. It is a combination of 
PBL and SVAT: The surface energy balance equations serve as 
a lower boundary constraint for a simple model of planetary 
boundary evolution, and the sensible heat flux happened on the 
surface layer could be related to variation of surface 
temperature. The primary strength of the methods is that it 
requires no more precious and spatialized air temperature as 
model input. 
The model has been validated using limited field data from 
Tongyu site of CEOP experiment, 2003. Comparisons between 
modeled and measured fluxes and air temperature show 
relatively small RMSE. And Bowen ratio shows an accepted 
correlation coefficient(r=0.76) in clear-sky cases. Because of 
the limited verification data and dates, the model results are 
preliminary and need further testing. 
The model can be improved in the follow aspect: A temporal 
scaling component would be introduced to fill the gaps 
contaminated by cloud; the spatial patterns of Bowen ratio 
should be compared with refined resolution image such as 
ASTER or ETM to analyze the influence of linear 
decomposition of Trad to soil temperature and canopy 
temperature using LAI. 
ACKNOWLEDGMENT 
Thanks to CEOP for providing fluxes and meteorological data 
of Tongyu station, 2002-2003. 
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