Barbera, Eliana (2014) COSMO-SkyMed polarimetric data for soil moisture retrieval: capability of SAR data for landslide monitoring. [Tesi di dottorato]

Preview

Text Barbera_Eliana_26.pdf Download (10MB) | Preview

Collection description

In the last years the interest in the study and monitoring of the Earth has been gradually growing, and many institutions have planned missions for these purposes. Synthetic Aperture Radar (SAR) is one of the most promising approaches to acquire images of every part of the world in short time. The characteristics that make the SAR a very powerful instrument are its capability to operate independently of weather conditions, at day and night, and to reach target that are inaccessible to ground measurement. There are many fields of interest for Earth Observation (both civilian and military), such as the detection and surveillance of ships or marine traffic, monitoring of agricultural fields, study of the winds in tropical storms and study of oceanic current, monitoring the damage caused by earthquakes, floods, tsunamis, inundation or other natural disasters, and more over. Natural disasters, in particular landslides, frequently affect our country, Italy. The hydrogeological risk is very high during rainy periods, and a space observation can be useful as support to civil protection in times of emergency, but also in the next phase of damage assessment. The knowledge of soil moisture behaviour is critical in different environmental and land activities; for example is the basis for prediction of river floods, rainfalls, avalanches and landslides. Given the link between specific soil parameters (such as moisture and surface roughness) and permittivity, it is possible to accurately measure these parameters with SAR data, starting from the measurements of the dielectric constant. The main problem is to separate the individual effects of the various parameters on the backscattered signal. However, this is possible using polarimetric data, in fact this data permits to minimize the effect of vegetation and surface roughness by using polarization ratios: combining cross- and co- polarizations ratios it can be possible to determine the soil moisture regardless of surface roughness. This research is funded by the Italian Space Agency in the framework of Cosmo-SkyMed Seconda Generazione project; it is focused on soil moisture retrieval by using polarimetric data. I analysed some Cosmo-SkyMed first generation polarimetric data (provided by courtesy of Italian Space Agency), in order to demonstrate the capability of the new generation of high resolution SAR system, and to suggest some possible upgrades or improvements for the new generation of ASI satellites.

Downloads

Actions (login required)

View Item