Assessment of the impact of spatial heterogeneity on microwave satellite soil moisture periodic error

REMOTE SENSING OF ENVIRONMENT

卷:205

Article

Lei, Fangni^1,2  Crow, Wade T.¹  Shen, Huanfeng²  Su, Chun-Hsu³  Holmes, Thomas R. H.⁴  Parinussa, Robert M.⁵  Wang, Guojie⁶ 

[1] USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA

[2] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Hubei, Peoples R China

[3] Univ Melbourne, Dept Infrastruct Engn, Parkville, Vic 3010, Australia

[4] NASA, GSFC Hydrol Sci Lab, Greenbelt, MD 20771 USA

[5] Transmissivity BV, VanderSat BV, Space Technol Business Pk,Huygenstr 34, NL-2201 DK Noordwijk, Netherlands

[6] Nanjing Univ Informat Sci & Technol, Sch Geog & Remote Sensing, Nanjing 210044, Jiangsu, Peoples R China

关键词: Microwave remote sensing;    Satellite-derived soil moisture;    Spectral analysis;    Periodicity;    Spatial heterogeneity;   

DOI  :  10.1016/j.rse.2017.11.002

来源: Elsevier

【 摘 要 】

An accurate temporal and spatial characterization of errors is required for the efficient processing, evaluation, and assimilation of remotely-sensed surface soil moisture retrievals. However, empirical evidence exists that passive microwave soil moisture retrievals are prone to periodic artifacts which may complicate their application in data assimilation systems (which commonly treat observational errors as being temporally white). In this paper, the link between such temporally-periodic errors and spatial land surface heterogeneity is examined. Both the synthetic experiment and site-specified cases reveal that, when combined with strong spatial heterogeneity, temporal periodicity in satellite sampling patterns (associated with exact repeat intervals of the polar-orbiting satellites) can lead to spurious high frequency spectral peaks in soil moisture retrievals. In addition, the global distribution of the most prominent and consistent 8-day spectral peak in the Advanced Microwave Scanning Radiometer Earth Observing System soil moisture retrievals is revealed via a peak detection method. Three spatial heterogeneity indicators based on microwave brightness temperature, land cover types, and long-term averaged vegetation index are proposed to characterize the degree to which the variability of land surface is capable of inducing periodic error into satellite-based soil moisture retrievals. Regions demonstrating 8-day periodic errors are generally consistent with those exhibiting relatively higher heterogeneity indicators. This implies a causal relationship between spatial land surface heterogeneity and temporal periodic error in remotely sensed surface soil moisture retrievals.

【 授权许可】

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