Sea Surface Slope and Elevation Statistics To Support Radar Performance Modeling

Light reflected from the ocean surface is highly polarized, where the state of the polarization is dependent on the orientation of the ocean surface. By measuring the Stokes vector of the reflected light Areté Associates proposes to retrieve both the cross-look and the look components of the surface slope. Algorithms will be developed in Phase I to retrieve the absolute slope values and the surface elevations. Also during Phase I a measurement and data collection system will be designed using a multi-spectral, polarimetric, area-scan, CCD-based digital camera system. Using cameras with large CCDs will enable this system to measure the slope vector at centimeter spatial scales over a patch size greater than 20 m by 20 m. By measuring the slopes over a sizeable patch, correlations between steep slopes and breaking events will also be recovered, which is of strong interest to the radar modeling community. BENEFITS: Radar scattering from the ocean surface depends strongly on the detailed ocean surface structure, which in turn is impacted by the wind and other environmental factors. Developing a capability to measure ocean surface slopes at a high resolution over a relatively large patch would aid greatly in the development of models of radar scattering from the ocean. Such measurements would provide detailed understanding of the structure of the ocean surface and of the air/sea interface. Measurement systems of this type would be of interest for radar model development and could be used in radar assessments when the ocean surface is involved. This capability would also be of interest in studies of the air-sea interaction and for monitoring the ocean surface by organizations such as NOAA and the Coast Guard.