**3.2 Satellite-based remote sensing**

High spatial resolution is necessary for analyzing soil moisture [101]. Thereby, satellites are the principal instruments for characterization and monitoring soil moisture with an accuracy of approximately 5 cm [102]. Ahlmer et al. [103] demonstrated that using satellite data enhances the reliability of flood forecasting. The microwave brightness temperature is sensitive to soil moisture content due to water affecting the dielectric constant [104]. In recent years, digital agriculture has made enormous progress in estimating soil moisture by applying microwave sensors. In contrast, advancements have been restrained owing to heterogeneities between satellite data resolution and hydrological scales, vegetation, and low microwave infiltration [105]. Satellite
