Side-looking airborne radar near Cape Hatteras, North Carolina, recorded images of ocean waves, wind streaks, and intermediate water bodies within the Gulf Stream front. In the enclosed waters of Pamlico Sound the radar images showed good accuracy in defining directions and distinguished waves from wind streaks at overlapping frequencies in the spectrum. In passing through the cyclonic shear in the Gulf stream front, waves from both sides turned to their left and so specified their directions of propagation. Differences between spectra obtained across the front are in accord with current refraction theory. An inverse wave refraction calculation furnished current shear values from which horizontal profiles of water velocity were compiled. The total calculated velocity change of 1.5 m/s is similar to previous measurements. A secondary front near shore contained a velocity difference of 0.25 m/s. Velocity changes across the Gulf Stream front were correlated with temperature changes. The radar there showed bands of high reflectivity at the edges of intermediate water bodies, whose temperature differences implied very small velocity steps. Increased roughness at the intermediate water boundaries was attributed to current interaction with waves. |