Non-uniform azimuth image shift caused by the pitching motion of ships observed in Radarsat images

Non-uniform azimuth image shift of a rigid body is observed, for the first time, in the Radarsat images of moving ships in pitching motion. The pitching velocity is estimated from the SAR image of a known ship, and compared with that computed using a numerical model with the meteorological and ship's data; further comparison is made with the wave orbital velocity. The results are shown to be all in excellent agreement. Comparisons are also made between the pitching velocities of unknown ships with the wave orbital velocity, and a reasonable agreement is obtained.