A Preliminary Evaluation of the SMAP Radiometer Soil Moisture Product Over United States and Europe Using Ground-Based Measurements

作者:Zeng, JY (Zeng, Jiangyuan)[ 1 ] ; Chen, KS (Chen, Kun-Shan)[ 1,2 ] ; Bi, HY (Bi, Haiyun)[ 3 ] ; Chen, Q (Chen, Quan)[ 4 ]

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING

卷: 54  期: 8  页: 4929-4940

DOI: 10.1109/TGRS.2016.2553085

出版年: AUG 2016

摘要

The Soil Moisture Active Passive (SMAP) mission, which is the newest L-band satellite that is specifically designed for soil moisture monitoring, was launched on January 31, 2015. A beta quality version of the SMAP radiometer soil moisture product was recently released to the public. It is crucial to evaluate the reliability of this product before it can be routinely used in hydrometeorological studies at a global scale. In this paper, we carried out a preliminary evaluation of the SMAP radiometer soil moisture product against in situ measurements collected from three networks that cover different climatic and land surface conditions, including two dense networks established in the U.S. and Finland, and one sparse network set up in Romania. Results show that the SMAP soil moisture product is in good agreement with the in situ measurements, although it exhibits dry or wet bias at different network regions. It well reproduces the temporal evolution and anomalies of the observed soil moisture with a favorable correlation greater than 0.7. The overall ubRMSE(unbiased root mean square error) of SMAP product is 0.036 m(3).m(-3), well within the mission requirement of 0.04 m(3).m(-3). The error sources of SMAP soil moisture product may be associated with the parameterization of vegetation and surface roughness but still needs to be tested and confirmed in more extent. Considering that the algorithms are still under refinement, it can be reasonably expected that hydrometeorological applications will benefit from the SMAP radiometer soil moisture product.

通讯作者地址: Zeng, JY (通讯作者)

Chinese Acad Sci, State Key Lab Remote Sensing Sci, Inst Remote Sensing & Digital Earth, Beijing 100101, Peoples R China.

地址:

[ 1 ] Chinese Acad Sci, State Key Lab Remote Sensing Sci, Inst Remote Sensing & Digital Earth, Beijing 100101, Peoples R China

[ 2 ] Univ Texas Arlington, Dept Elect Engn, Arlington, TX 76019 USA

[ 3 ] China Earthquake Adm, Key Lab Earthquake Dynam, Inst Geol, Beijing 100029, Peoples R China

[ 4 ] Chinese Acad Sci, Airborne Remote Sensing Ctr, Inst Remote Sensing & Digital Earth, Beijing 100094, Peoples R China