Soil Moisture from ASCAT
Sebastian Hahn from the Vienna Technical University talks in his presentation about the different sensors for the retrieval of soil moisture onboard polar orbiting satellites and describes the SM algorithm developed at the TU-Wien.
Although soil moisture represents only about 0.005% of the global water resources, it is one of the crucial variables in hydrological processes, influencing the exchange of water and energy fluxes at the land/atmosphere interface. For many environmental studies it is important to have accurate estimates of the spatial and temporal variations of soil moisture (e.g. hydrology, meteorology). Advances in satellite remote sensing have shown the potential of estimating soil moisture using various remote sensing techniques. This presentation will focus on an introduction using active and passive microwave remote sensing for the retrieval of soil moisture. In case of the active retrieval a detailed description of the semi-empirical model used for the METOP ASCAT soil moisture product will be shown step by step, especially highlighting assumptions and limitations. In the end various applications using satellite based soil moisture products will be summarised.