|| During the last decades the need for a global estimation with high temporal resolution of key environmental variables such as soil moisture and ocean salinity has grown greatly (Robock et al. 2000; Dai et al. 2004; Roemmich et al. 2000). Satellites represent the best mean for satisfying such need, and several instruments have been launched on-board European and American satellites with the intent of retrieving large-scale soil moisture and ocean salinity maps.
These instruments are based on different principles. They may involve radiometers (Njoku et al. 2003), scatterometers (Bartalis et al. 2007), interferometric radiometers (Kerr et al. 2001), or they may rely on both passive and active elements (LeVine et al. 2007; Entekhabi et al. 2010).
Although different technologies were adopted, all these instruments are limited by a native spatial resolution of few tens of kilometers. In order to be able to make use of these data in hydrological models, and for many other applications, like the survey of water resources at the scale of irrigated zones, a better spatial resolution must be achieved, typically it should be improved by an order of magnitude.
To assure continuous monitoring of soil moisture and ocean salinity, while attaining an unprecedented fine spatial resolution, an original concept was proposed in Kerr et al. 2010, which aims at achieving a spatial resolution of few kilometers while maintaining the same radiometric resolution. The concept relies on a two prong approach. a) capitalize on the 2D interferometric system and suppress the aliasing issue while reducing the noise level and b) use fully the spectrum to gain a factor 2 in resolution. The structure is a square to enable exploring the angular range across the whole swath. It will also include a RFI detection system. The project has been submitted for a CNES phase 0.
This presentation will give an overview of the new concept : SMOS HR, together with project status and the main accomplishments in terms of theoretical modelling of the instrument hardware principle validation and next steps.|