Active-Passive Soil Moisture Retrievals During the SMAP Validation Experiment 2012

作者：Leroux Delphine J; Das Narendra N^*; Entekhabi Dara; Colliander Andreas; Njoku Eni; Jackson Thomas J; Yueh Simon

来源：IEEE Geoscience and Remote Sensing Letters, 2016, 13(4): 475-479.

DOI：10.1109/LGRS.2015.2491643

• Active-passive
• brightness temperature disaggregation
• SMAP
• soil moisture

The goal of this study is to assess the performance of the active-passive algorithm for the NASA Soil Moisture Active Passive mission (SMAP) using airborne and ground observations from a field campaign. The SMAP active-passive algorithm disaggregates the coarse-resolution radiometer brightness temperature (TB) using high-resolution radar backscatter (sigma(o)) observations. The colocated TB and sigma(o) acquired by the aircraft-based Passive Active L-and S-band sensor during the SMAP Validation Experiment 2012 (SMAPVEX12) are used to evaluate this algorithm. The estimation of its parameters is affected by changes in vegetation during the campaign. Key features of the campaign were the wide range of vegetation growth and soil moisture conditions during the experiment period. The algorithm performance is evaluated by comparing retrieved soil moisture from the disaggregated brightness temperatures to in situ soil moisture measurements. A minimum performance algorithm is also applied, where the radar data are withheld. The minimum performance algorithm serves as a benchmark to asses the value of the radar to the SMAP active-passive algorithm. The temporal correlation between ground samples and the SMAP active-passive algorithm is improved by 21% relative to minimum performance. The unbiased root-mean-square error is decreased by 15% overall.

• 出版日期2016-4