%0 Journal Article %T Peakedness Effects in Near-Nadir Radar Observations of the Sea Surface %+ 1 %+ Laboratoire d'Océanographie Spatiale (LOS) %A Bringer, Alexandra %A Guérin, Charles-Antoine %A Chapron, Bertrand %A Mouche, Alexis %< avec comité de lecture %Z MIO:12-075 %@ 0196-2892 %J IEEE Transactions on Geoscience and Remote Sensing %I Institute of Electrical and Electronics Engineers %V 50 %N 9 %P 3293--3301 %8 2012-09-01 %D 2012 %R 10.1109/TGRS.2012.2183605 %K nadir NRCS %K microwave ocean remote sensing %K peakedness %K multi-band %Z Physics [physics]/Physics [physics]/General Physics [physics.gen-ph]Journal articles %X The simulation and interpretation of microwave sea radar return in the near-nadir region is still an issue in view of the limitations of the Geometrical Optics approximation and the multi-scale and non-Gaussian nature of the surface. We show that an unambiguous and fully consistent physical approach can be reached in the framework of the Physical Optics. The model is developed on the basis of various satellite and airborne C-, Ku- and Ka-band measurements using different reference surface roughness spectra. As found the introduction of a peakedness correction based upon the excess kurtosis of slopes is necessary to obtain consistent analysis across the microwave frequency range. The model yields accurate simulations for the omnidirectional near-nadir NRCS in different frequency bands, provided the spectrum satisfies some a priori constraints on the distribution of total and filtered slopes. %G English %L hal-00743902 %U https://hal.science/hal-00743902 %~ INSU %~ UNIV-TLN %~ CNRS %~ UNIV-AMU %~ IFREMER %~ MIO %~ OSU-INSTITUT-PYTHEAS %~ CMM %~ MIO-OPLC %~ ANR