Mapping soil moisture and inundation at high resolution

The course aims at introducing to the use of SAR for hydrological applications. In particular, in order to generate soil moisture maps at high resolution and inundation maps. The course provides foundations on the physical mechanisms which determine the sensitivity of the radar to water (water in the soil and standing water) and the confounding effects of topography, vegetation, roughness, land cover in general. The foundations of SAR imaging, the main characteristics of the images and the algorithm that can be used to generate the final products are also illustrated. The satellite missions that can be used to this scope and some elementary pre-processing steps are presented using the SNAP software package.

The content of the course is the following.

Introduction to remote sensing. Synthetic Aperture Radar principles. Main characteristics of SAR images. Radar observables and radar equation. System requirements for moisture and flood mapping. Introduction to electromagnetic interaction. Scattering from rough soil. Physical Optics, Geometric Optics and Small Perturbation Models. Volume scattering from vegetation.  The Water Cloud Model and Double Bounce. Approaches to estimate soil moisture from SAR: change detection, data-driven, multitemporal, merging of radiometric and radar data. Multitemporal Bayesian retrieval of soil moisture. SAR-based flood mapping principles. SAR-based flood mapping over vegetated areas. SAR-based flood mapping over urban areas. SAR based satellite missions. Elements of preprocessing of Sentinel-1 data using SNAP.