Research News

Study Reveals Impact of Surface Heterogeneity on Satellite Soil Moisture Products

March 25, 2024

A study conducted by researchers at the State Key Laboratory of Remote Sensing Science, the Aerospace Information Research Institute (AIR) under the Chinese Academy of Sciences (CAS), sheds light on the reliability and error tracing of microwave soil moisture products on a global scale. 

Led by associate professor ZENG Jiangyuan from AIR, the team utilized various assessment strategies to evaluate the accuracy of eight state-of-the-art microwave soil moisture products. The study was published in the IEEE Transactions on Geoscience and Remote Sensing on Feb.05, 2024.

Soil moisture, crucial for water, carbon, and energy cycles, serves as a vital component of soil and a primary water source for plants. Microwave remote sensing, with its capability for all-weather, all-day observation and sensitivity to soil dielectric properties, stands out as the most effective means for large-scale soil moisture monitoring.

The study compared three evaluation methods: model/reanalysis-based cross-validation, global dense observational networks, and the Extended Triple Collocation (ETC) method. By employing these methods, the team provided comprehensive assessments of the soil moisture products while highlighting their strengths and limitations. Notably, they uncovered the non-ignorable impact of surface heterogeneity, mainly including the heterogeneity in vegetation coverage, land cover types, and terrain, on product accuracy.

The findings underscore the necessity of considering surface heterogeneity in soil moisture retrieval algorithms, as existing methods often overlook these effects. Addressing this gap could lead to further improvements in soil moisture retrieval accuracy, enhancing the reliability of these critical environmental monitoring datasets.

Contact: luyq@aircas.ac.cn