Since the beginning of SMOS (Soil Moisture and Ocean Salinity) activities, field campaigns have been of great importance to calibrate the model and validate the SMOS derived soil moisture. Many sites have been equipped with soil moisture probes and even with L-Band radiometer like Smosrex in France, Vas in the Valencia region, Jülich in Germany, Sodankyla in Finland. In these cases, the L-band radiometers have been placed on structures about 10 meters above ground level, observing a unique surface, i.e. one type of vegetation cover, whereas the SMOS instrument characterized by a radiometric resolution of ~40km is observing a mix of different landscapes. Keeping this issue in mind, a new experimental site is proposed here with the main objective to observe complex scenes (similar to SMOS instrument) and to test and improve SMOS soil moisture retrieval. The LEWIS (L-Band radiometer for Estimating Water in Soil) radiometer has been placed by a cliff in St Hilaire du Touvet, in the French Alps near Grenoble since May 2014. Its position allows us to monitor a flat valley 800 meters below. With a beamwidth of 13.6°, the observed areas are about 300-500 meters wide. The instrument - equipped with 2 motors - moves in two directions (azimuth and elevation) monitoring continuously various targets composed with agricultural fields, forest and the Montfort marshes. In addition, soil moisture and temperatures probes (theta probes and Cosmos) are placed in 3 locations in the valley, and a pyrometer is installed with the radiometer to measure the skin temperature of the observed scenes. The aim of this communication is to present its setting and the first results of a long continuous time series of soil moisture and L-band brightness temperatures.< Leer menos