干旱区生态环境知识资源中心(Arid): True global error maps for SMAP, SMOS, and ASCAT soil moisture data based on machine learning and triple collocation analysis

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DOI	10.1016/j.rse.2023.113776
	True global error maps for SMAP, SMOS, and ASCAT soil moisture data based on machine learning and triple collocation analysis
	Kim, Hyunglok; Crow, Wade; Li, Xiaojun; Wagner, Wolfgang; Hahn, Sebastian; Lakshmi, Venkataraman
通讯作者	Kim, H
来源期刊	REMOTE SENSING OF ENVIRONMENT
ISSN	0034-4257
EISSN	1879-0704
出版年	2023
卷号	298
英文摘要	Quantifying the accuracy of the satellite-based soil moisture (SM) data is important for a number of key applications, such as: combining satellite-basedSM products for long-term SM analyses, assimilating SM data into land surface models, and providing quality flags to mask bad quality SM data. A range of statistical methods have been proposed to estimate error statistics for large-scale SM datasets including the: instrumental variable (IV) method, triple collocation analysis (TCA), and quadruple collocation analysis (QCDA). While requiring only two input products, the IV method also imposes an additional assumption that one input product possesses serially uncorrelated errors -thus limiting its scope compared to TC. Likewise, QCDA requires four independent SM data products that are difficult to obtain and may not always be available for analysis. Nonetheless, TCA-based methods still cannot provide truly global error maps for satellite SM products due to the limited number of independent SM products and difficulties with baseline TCA assumptions. Moreover, temporal sampling requirements for TCA are often impractical because of low SM retrieval skill in forested and arid areas - as well as in regions prone to radio frequency interference.Here, we seek to fill significant spatial gaps in TCA results using machine learning (ML) and therefore provide spatially complete error maps for the satellite-based SM data products derived from the Soil Moisture Active Passive (SMAP), Soil Moisture and Ocean Salinity (SMOS), and Advanced Scatterometer (ASCAT) systems. Furthermore, we use SHapley Additive exPlanations (SHAP) values, a model-agnostic technique for interpreting ML models, to examine the impact of various environmental conditions on the quality of satellite-based SM retrievals.Globally, and across all three products, 72.0% of missing error information in a TCA-based analysis, due to either the lack of valid data or the inability of TCA to provide reliable results, can be reconstructed from the ensemble prediction mean of the ML models. Overall, we found that 22.7% (a.m.) and 34.2% (p.m.) of the Earth'sSM dynamics (between 60 degrees S to 60 degrees N) have not been investigated properly across all three satellite missions.
英文关键词	Machine learning Triple collocation analysis Remotely sensed soil moisture Time -varying geophysical data Quality control
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:001074756600001
WOS关键词	VEGETATION OPTICAL DEPTH ; INTERFERENCE ; METHODOLOGY ; VALIDATION ; PRODUCT ; ALBEDO
WOS类目	Environmental Sciences ; Remote Sensing ; Imaging Science & Photographic Technology
WOS研究方向	Environmental Sciences & Ecology ; Remote Sensing ; Imaging Science & Photographic Technology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/398359
推荐引用方式 GB/T 7714	Kim, Hyunglok,Crow, Wade,Li, Xiaojun,et al. True global error maps for SMAP, SMOS, and ASCAT soil moisture data based on machine learning and triple collocation analysis[J],2023,298.
APA	Kim, Hyunglok,Crow, Wade,Li, Xiaojun,Wagner, Wolfgang,Hahn, Sebastian,&Lakshmi, Venkataraman.(2023).True global error maps for SMAP, SMOS, and ASCAT soil moisture data based on machine learning and triple collocation analysis.REMOTE SENSING OF ENVIRONMENT,298.
MLA	Kim, Hyunglok,et al."True global error maps for SMAP, SMOS, and ASCAT soil moisture data based on machine learning and triple collocation analysis".REMOTE SENSING OF ENVIRONMENT 298(2023).