Multifrequency analysis of radar sea clutter directionnal asymmetries

International audience; This paper reports the first results inferred from the investigation of sea clutter azimuthal variations and their dependence on the radar electromagnetic frequency. We summarize the results derived from the study of SAR data acquired simultaneously at X-and L-band by ONERA (The French aerospace laboratory) and compare them to results stemming from other experiments in the literature. The conclusions drawn suggest that the azimuthal asymmetry is more pronounced at X than L band, potentially indicating that the directional asymmetry of the NRCS is gradually diminished as the frequency decreases. This seems to entail that the asymmetry is likely associated to the small scales of roughness whose electromagnetic returns are measured at X band and not at L band.