The Synthetic Aperture Radars (SARs) on ERS and RADARSAT are sensitive to changes in the small-scale surface roughness present on the ocean surface, which is altered by the velocity field associated with internal waves. More than 2600 SAR images from Norwegian waters were analyzed to obtain geometric and radiometric signature statistics of internal waves. The statistical analysis shows that the dispersion properties can be described by a single wavelength scaling parameter of 1.4, allowing internal waves to be detected and characterized with a wavelet based algorithm. Internal waves are identified mainly in four hot-spot areas with somewhat distinctive characteristics. Information on internal waves is useful for the offshore oil industry and for the military, both for planning purposes and operationally in near real time. ¿ 2001 American Geophysical Union