李丽等:A New Algorithm of the FPAR Product in the Heihe River Basin Considering the Contributions of Direct and Diffuse Solar Radiation Separately
被阅读 1161 次
2015-10-23
A New Algorithm of the FPAR Product in the Heihe River Basin Considering the Contributions of Direct and Diffuse Solar Radiation Separately
作者:Li, L (Li, Li)[ 1 ] ; Du, YM (Du, Yongming)[ 1 ] ; Tang, Y (Tang, Yong)[ 1 ] ; Xin, XZ (Xin, Xiaozhou)[ 1 ] ; Zhang, HL (Zhang, Hailong)[ 1 ] ; Wen, JG (Wen, Jianguang)[ 1 ] ; Liu, QH (Liu, Qinhuo)[ 1,2 ]
REMOTE SENSING
卷: 7  期: 5  页: 6414-6432
DOI: 10.3390/rs70506414
出版年: MAY 2015
 
摘要
It remains a challenging issue to accurately estimate the fraction of absorbed photosynthetically-active radiation (FPAR) using remote sensing data, as the direct and diffuse radiation reaching the vegetation canopy have different effects for FPAR. In this research, a FPAR inversion model was developed that may distinguish direct and diffuse radiation (the DnD model) based on the energy budget balance principle. Taking different solar zenith angles and diffuse PAR proportions as inputs, the instantaneous FPAR could be calculated. As the leaf area index (LAI) and surface albedo do not vary in a short periods, the FPAR not only on a clear day, but also on a cloudy day may be calculated. This new method was used to produce the FPAR products in the Heihe River Basin with the Moderate-Resolution Imaging Spectroradiometer (MODIS) LAI and surface albedo products as the input data source. The instantaneous FPAR was validated by using field-measured data (RMSE is 0.03, R-2 is 0.85). The daily average FPAR was compared with the MODIS FPAR product. The inversion results and the MODIS FPAR product are highly correlated, but the MODIS FPAR product is slightly high in forest areas, which is in agreement with other studies for MODIS FPAR products.
 
通讯作者地址: Liu, QH (通讯作者)
Chinese Acad Sci, Inst Remote Sensing & Digital Earth, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China.
地址:
[ 1 ] Chinese Acad Sci, Inst Remote Sensing & Digital Earth, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China
[ 2 ] JCGCS, Beijing 100875, Peoples R China