Use of microwave remote sensing data to monitor spatio temporal characteristics of surface soil moisture at local and regional scales

摘要

Hydrologic processes, such as runoff production or evapotranspiration,largely depend on the variation of soil moisture and its spatial pattern.The interaction of electromagnetic waves with the land surface can bedependant on the water content of the uppermost soil layer. Especially inthe microwave domain of the electromagnetic spectrum, this is the case. Newsensors as e.g. ENVISAT ASAR, allow for frequent, synoptically andhomogeneous image acquisitions over larger areas. Parameter inversion modelsare therefore developed to derive bio- and geophysical parameters from theimage products. The paper presents a soil moisture inversion model forENVISAT ASAR data for local and regional scale applications. The model isvalidated against in situ soil moisture measurements. The various sources ofuncertainties, being related to the inversion process are assessed andquantified.