Check of ocean observation capability of JERS-1 SAR

The Japanese Earth Observation Satellite-1 (JERS-1) carries an L-band synthetic aperture radar (SAR) with HH-polarization and the incidence angle of 39 degree. The main purpose of the satellite is to observe land targets. Because of the discharge trouble in the antenna, the transmitting power of JERS-1/SAR has been decreased to 1/4 of the first designed value. The conditions are serious for application of JERS-1/SAR to ocean observation. The authors have estimated the capability of JERS-1/SAR in observation of the ocean surfaces for various wind speeds, using the buoy data obtained by Japan Meteorological Agency (JMA). The result is pessimistic. Not only qualitative investigations but also quantitative ones may be impossible, because of the very low SNR even for high sea states with the wind speeds larger than 10 m/s. The authors have also estimated the L-band σ⁰ and its wind speed dependence at the incidence angle of 39 degree