SWIM: A Multi-Incidence Beams Ku-band Real Aperture Radar for the Observation of the Ocean Wave Field Spectra

• Main Authors: Enjolras, V., Caubet, E., Richard, J., Lorenzo, J., Carayon, G., Castillanr, P.
• Format: Conference Proceeding
• Language: English
• Subjects: architecture; Azimuth; Extraterrestrial measurements; Instruments; ocean wave; Ocean waves; processing; radar; Radar cross section; Sea measurements; Sea surface; Spaceborne radar; Surface waves; Velocity measurement
• ISSN: 2153-6996; 2153-7003
• DOI: 10.1109/IGARSS.2008.4780071

The instrument SWIM (Surface Waves Investigation and Monitoring) on the CFOSAT (Chinese French Oceanographic Satellite) project aims at measuring the directional spectra of ocean waves on a 180 km wide swath. Orbiting on a 500 km sun-synchronous orbit, it provides with a global full coverage of the oceans between -80 and 80deg. It consists in a real aperture radar (RAR) operating in Ku-band (13.575 GHz) on 6 distinct beams pointing at incidence angles from 0deg (nadir) to 10deg, while scanning the whole azimuth angles (0-360deg). The nadir beam is similar to the one provided by a standard altimeter. Its main objective is to measure the significant wave height and wind speed (from the measurement of the radar cross section). Radar cross-sections are also estimated from 2 to 10deg off-nadir observations, then ensuring the access to profiles dependence with incidence and azimuth angles. Appropriate processes of observations at 4 to 10deg incidence provide with an estimate of the spectral properties of the local wave field.