Real aperture radar imaging of ocean waves during SAXON‐FPN: A case of azimuth‐traveling waves

Abstract

This paper investigates the radar imaging of ocean waves under two separate wind speed and sea state conditions using an X band real aperture radar (RAR). It is shown experimentally that for the case of higher sea state and wind speed (9.1 m/s), the RAR is capable of imaging the waves from all directions including the azimuth. The case for low sea state and wind speed (4.5 m/s), however, shows somewhat stronger imaging contrast in the range direction with reduced contrast for the azimuth‐traveling waves. The results of the aircraft observations are compared with numerical simulations of a RAR imaging model. Simulations show that cross tilt is a viable mechanism for enhancing the azimuthal modulations, but the results are sensitive to the level of upwind/cross‐wind anisotropy of the shortwave spectrum. Simulations also show that the variations in incidence angle create irregularities in the azimuthal angle distribution.