Recent advances in land monitoring using GNSS-R techniques

Soil moisture and land surface's temperature are proxys of forest fires risk. In the frame of the DANTE project, ADTelecom (Barcelona, Spain) is working in the design of an instrument: 1) to estimate the risk of forest fires, based on surface temperature and soil moisture measurements, 2) to detect and localize the ignition of forest fires by image processing techniques, and finally, once the forest fire has ignited, 3) to estimate the direction of propagation of the fire based on short-range wind lidars. This paper is focused on the design of the soil moisture remote sensor. To do that, some of the existing techniques for ground-based soil moisture monitoring based on the use of signals of opportunity transmitted from Global Navigation Satellite Systems after reflection on the land surface are first reviewed. Then, some conclusions drawn to design a new and simpler remote sensing instrument for soil moisture monitoring taking the advantages of all each of the individual systems revised before. Finally, the instrument developed is presented together with some preliminary results, pending on the development of more refined retrieval methods through the processing of more experimental data.