The detection of internal waves in the North Atlantic using real aperture airborne radar

Abstract

The surface signatures of numerous internal waves in the North Atlantic Ocean were clearly imaged by an airborne real aperture radar on a series of flights during the summer of 1983. The present work describes a preliminary analysis of the data recorded on these flights. A ship-borne acoustic echo sounder provided a measurement of the displacement of the deep scattering layer from which an estimate of the average wavelength and amplitude of an internal wave group propagating in the same sea area is made. Further work is in progress to interpret the radar signatures and to deduce from them information about the density stratification in the deep interior of the ocean. The survey shows that real aperture aircraft-borne radars can, like synthetic aperture radars on aircraft and satellites, provide excellent imagery of the surface signatures of internal waves without requiring the extensive signal processing generally involved with the latter technique and that the northern approaches to the U.K. provide rich and relatively accessible sources of internal waves for further study.