短波红外垂直失水指数观测误差估计方法及其同化方案

发展了一个基于短波红外垂直失水指数的土壤水分观测误差空间分析方法,据此改进了以遥感和生态过程模型为基础的两阶段土壤水分同化方案.通过实地同化实验,证明了改进的土壤水分同化方案能较好地体现空间植被覆盖和数量的异质性导致的表层土壤水分的空间变异,进一步提高了遥感数据在空间上的同化精度.

Estimates of observation error based on shortwave infrared perpendicular water stress index for regional assimilation

Confirming observation operator and its spatial form of error variance is especially important for regional data assimilation scheme. In previous studies, observation error derived from remote sensing data is assumed only correlated with time while its spatial heterogeneity is often ignored. This assuming alleviates the computing pressure while also brings error to the assimilation process. In this study, new method for estimating the observation error based on shortwave infrared perpendicular water stress index was presented. The new observation error estimation method was further used into a two stage data assimilation scheme. From data assimilation experiment, it was demonstrated that the improved data assimilation scheme can fairly reveal spatial variations of surface soil moisture resulted from spatial and quantitative heterogeneous of vegetation and further improve assimilation accuracy.