Measurement of wave coherence properties using spaceborne synthetic aperture radar

There has been considerable recent interest in assessing the feasibility of constructing very large offshore structures with linear dimensions of over a kilometer. The climatology of very long ocean surface wave fields which might resonate with such structures fall outside the experience of conventional maritime design. Of particular importance are properties of wave coherence, i.e. wave groupiness and wave crest length. Spaceborne synthetic aperture radars produce high-resolution wave images over swaths 100 km wide or larger. In this paper, we review the theory of wave imaging by synthetic aperture radar, describe techniques to objectively measure the properties of wave groupiness and crest length, and apply these techniques to synthetic aperture radar images in the vicinity of hurricanes. We show that wave groupiness and wave long-crestedness are more prevalent than one might expect purely on the basis of the associated ocean wave spectrum.