The Upper Danube soil moisture validation site: measurements and activities

Abstract

The validation of soil moisture products from ESA’s Soil Moisture and Ocean Salinity (SMOS) mission requires the maintenance of long term soil moisture monitoring sites. The Upper Danube catchment, situated mostly in Southern Germany, was chosen as one of two main test sites in Europe for the SMOS cal/val activities. Its main part is situated in the alpine foreland with heterogenous land cover and large natural gradients from the Alps northwards. Best soil moisture retrieval performance is expected in the smaller catchment of the river Vils, because there are neither open water bodies nor large urban areas and terrain as well as soil texture are fairly homogeneous. The Vils reference site is equipped with a more dense network of currently 5 soil moisture measuring stations as it is the focus of flight campaigns and studies of scaling issues. THE UPPER DANUBE SOIL MOISTURE VALIDATION SITE: MEASUREMENTS AND ACTIVITIES