Passive remote sensing based upon electromagnetic sources of opportunity provides the promise of a useful tool for monitoring natural environments and especially marine environments [1], [2], [3]. In this context, the Global Navigation Satellite Systems GNSS (GPS,...) appear as one of the most relevant solution since the emitted signals (in LBand) are reliable, available all over the world, deterministic and perfectly known. In this study, we propose to analyze and to assess the possibility of sensing the sea wave movements using the reflected L-Band signals (see figure 1). Thus, based upon numerical simulations of the electromagnetic scattered field (Method of Moments), we investigate the connections between a time evolving surface and the features in the timefrequency (TF) domain of the signal scattered by this surface (using Wigner-Ville transform). The idea is to take advantage of these representations to extract from Doppler and micro- Doppler signatures the oceanographic parameters of interest