Wind, slick, and fishing boat observations with Radarsat ScanSAR

The wide swath (450 km) of ScanSAR (synthetic aperture radar) images provides a greater opportunity for imaging surface phenomena and sporadic events, as well as fuller coverage of large-area patterns than the 100-km swaths of previous satellite SARs. To evaluate the ability of Radarsat ScanSAR to yield wind speed, we compare scaled radar intensities with wind speeds and directions measured by an array of buoys. The root-me an-square difference was less than 2 mis in wind speed for 173 estimates. Among the Radarsat images were several showing large-scale dark slicks. Attempts to link these patterns to surfactants produced by bright plankton blooms detected in Advanced Very High Resolution Radiometer imagery were unsuccessful. Two images coincided with openings for seine fishing operations. In addition, boats with lengths of 18 to 25m were clearly visible, even though the radar signals were near the lower detection limit.