A synthetic aperture imaging radar flown on the NASA CV-990 aircraft has yielded pictures of ocean features interpreted as being due to short wavelength internal waves. Wave packets similar to those detected from the Landsat-1 satellite and other platforms have been observed off the coast of Alaska under conditions suitable for tidal excitation of internal waves. Both the radar and the Landsat images show variations in reflectivity across each wave in a packet that range from low to high to normal. The variations are evidence for the simultaneous existence of two mechanisms proposed to explain surface signatures of internal waves; roughening due to wave-current interactions and smoothing due to slick formation. The rough region leads the smooth one in phase by one-fourth to one-half a wavelength.