The study of vegetation repartition and evolution is a wide research field and application task for environmental modeling. The objective of our study is to discriminate different vegetation types by their temporal evolution. For that purpose, we use two different sensors: the SPOT sensor provides monthly data with a sufficient spatial resolution, while the NOAA sensor provides daily data, but with a poor spatial resolution. Combining these two complementary sensors seems to be a promising way to lead the study. We propose here a three-step experiment showing that the simultaneous use of these two sensors allows us to obtain a fine segmentation of land cover.