Rain rate observation by radar altimeter

The importance of precipitation in understanding the hydrological cycle and climate is well established. Global information on the three dimensional structure of rainfall is of paramount importance for the interpretation of precipitation processes, for the detection of climate change and the validation of numerical weather prediction models. This need has been clearly expressed through the GEWEX (Global Energy and Water Cycle Experiment) program. A spaceborne radar is a very attractive way to obtain global three dimensional rainfall data. In order to satisfy scientific requirement, the idea to modify the existing planned radar altimeter RA-2 belonging to the ENVISAT-1 mission has gained increasing interest. A detailed feasibility study is in progress in Alenia Spazio under ESA contract. The preliminary results of the study are presented