Radar measurement of directional ocean wave spectra at low incidence angles†

Abstract

Abstract There exist several techniques for the measurement of directional ocean wave spectra. The most conventional technique is the employment of pitch-roll buoys but a disadvantage of this technique is that it measures at a fixed point. Another promising technique is the use of airborne or spaceborne radars. We present here results of a comparison between the data from an airborne radar, which is measuring near vertical incidence, and measurements of directional wave spectra obtained by means of a pitch-roll buoy and processed by using the Long-Hasselmann iterative algorithm. Although preliminary, these results constitute a step towards the employment of the airborne radar based on the Radar Ocean Wave Spectrometer (ROWS) principle as defined by Jackson (1981), as a validation tool for spaceborne synthetic aperture radars.