A Study of the Validation Method of Remotely Sensed Evapotranspiration based on Observation Data
A comprehensive validation method of remotely sensed Evapotranspiration (ET) based on observation data was proposed to ensure the accuracy of estimated ET. Thus, an observation system was equipped with a large aperture scintillometer, an eddy covariance system and an automatic weather station, and then an observation network was established at Miyun, Guantao, Daxing and Xiaotangshan sites in Hai river basin, which were set up from 2002 for ET and correlative parameters measurements at different satellite pixel scales. On this basis, rigorous data process and quality control were executed to ensure the high quality of observations. Meanwhile, a validation procedure of remotely sensed ET based on ground measurements was presented, and the method of selecting validation pixels and evaluation index were investigated intensively. According to this method, validation of remote sensing ET was performed in Beijing. Based on the LAS measurements at Miyun and Daxing sites in 2008, regional ET in Beijing area estimated by MODIS data was validated. The results demonstrated that the proposed validation method based on LAS observation data was feasible. The RMSE and MRE of estimated monthly and daily ET were 13. 75、0.91 mm and 22. 79%、18. 61% respectively.
NETL
NSTL
万方数据
维普
