Techniques to extract the structure of the marine atmospheric boundary layer from SAR images

Two techniques suitable for detecting non-periodic backscatter structures in the SAR images are presented: the Variable Interval Space Averaging (VISA) and the two-dimensional Continuous Wavelet Transform (CWT2) analyses. Both methods have been tested over SAR images taken under different geophysical situations. Despite these techniques require the definition of subjective parameters and the knowledge of the spatial scales of interest, the results indicate that they succeed in the identification of the non-periodic backscatter structures present in the SAR images, which may be referred to the imprint of the atmospheric boundary layer. This will allow the quantitative estimate of the size, number and orientation of the backscatter structures. On the contrary, when periodic structures as the wind rolls are present, only the CWT2 yields good results. An interesting development of these techniques will consist of the possibility to distinguish atmospheric from oceanographic features.