%0 Journal Article
%A Tongren Xu
%A Shaomin Liu
%A Lu Xu
%A Yujie Chen
%A Zhenzhen Jia
%A Ziwei Xu
%A Jeffrey Nielson
%+ State Key Laboratory of Remote Sensing Science, Research Center for Remote Sensing and GIS, and School of Geography, Beijing Normal University, No.19, Xinjiekouwai Street, 100875 Beijing, China;;Information Technology Department, National Library of China, No. 33, Zhongguancun Nandajie, 100081 Beijing, China;;Yangzhou Environmental Monitoring Center, No.446, Yangzijiangbei Road, 225007 Yangzhou, China;;Department of Civil and Environmental Engineering and Water Resource Research Center, University of Hawaii at Manoa, Honolulu, HI 96822, USA
%T Temporal Upscaling and Reconstruction of Thermal Remotely Sensed Instantaneous Evapotranspiration
%J Remote Sensing
%D 2015
%N 3
%V 7
%K evapotranspiration;thermal remote sensing;temporal upscaling;continuously daily ET reconstruction;regional ET production
%X Currently, thermal remote sensing-based evapotranspiration (ET) models can only calculate instantaneous ET at the time of satellite overpass. Five temporal upscaling methods, namely, constant evaporative fraction (ConEF), corrected ConEF (CorEF), diurnal evaporative fraction (DiEF), constant solar radiation ratio (SolRad), and constant reference evaporative fraction (ConET<sub>r</sub>F), were selected to upscale the instantaneous ET to daily values. Moreover, five temporal reconstruction approaches, namely, data assimilation (ET_EnKF and ET_SCE_UA), surface resistance (ET_SR), reference evapotranspiration (ET_ET<sub>r</sub>F), and harmonic analysis of time series (ET_HANTS), were used to produce continuous daily ET with discrete clear-sky daily ET values. For clear-sky daily ET generation, SolRad and ConET<sub>r</sub>F produced the best estimates. In contrast, ConEF usually underestimated the daily ET. The optimum method, however, was found by combining SolRad and ConET<sub>r</sub>F, which produced the lowest root-mean-square error (RMSE) values. For continuous daily ET production, ET_ET<sub>r</sub>F and ET_SCE_UA performed the best, whereas the ET_SR and ET_HANTS methods had large errors. The annual ET distributions over the Beijing area were calculated with these methods. The spatial ET distributions from ET_ET<sub>r</sub>F and ET_SCE_UA had the same trend as ETWatch products, and had a smaller RMSE when compared with ET observations derived from the water balance method.
%W CNKI