On the detection of spatially varying current fields at the ocean surface by along-track interferometric synthetic aperture radar

The phase information in along-track interferometric synthetic aperture radar (along-track INSAR, ATI) images is a measure of the Doppler offset of the backscattered signal and thus of the line-of-sight velocity of the scatterers. It is hoped that this information can be exploited for oceanic surface current measurements from aircraft or spacecraft. However, the Doppler offset of the radar backscatter from the ocean arises not exclusively from the mean surface current, but it includes contributions associated with surface wave motions. The authors have developed a very efficient model for the computation of these contributions and of the complete Doppler spectra. In this work, they present the theoretical concept of the model and discuss the actual possibilities and limitations of oceanic current measurements by ATI