Since Synthetic Aperture Radar (SAR) can produce radar cross-sectional images at 100m resolution over swaths of hundreds of kilometers, it has great utility for mapping the winds over Alaskan waters. Radar cross section depends on the wind speed and direction with respect to the SAR look angle. As the ocean surface becomes rougher, with higher wind speed, the backscatter return grows. Using software developed at Johns Hopkins University Applied Physics Lab, it is possible to extract wind speeds between 0 and 40 knots, with an accuracy on the order of 3 knots.

The Alaska Satellite Facility (ASF) routinely downlinks SAR imagery over the Pacific Ocean, the Bering Sea, and the Arctic Ocean. All of this ScanSAR data is processed in near-real time to yield wind speed plots. Unlike other space-borne techniques for determining wind speed, SAR offers much higher resolution and provides accurate results in coastal waters. Using this web page, users will be able to access the most current wind speed data or retrieve retrospective data from the archives.