The 3-dimension sea surface is simulated by using empirical sea wave spectrum

and then the radar cross section is computed with the use of specular reflection theory.The signal returned from sea surface is then computed by employing radar equation and synthetic processing to simulate sea surface echo wave.Although there is no synthetic aperture radar altimeter data at present

the simulation result shows that synthetic aperture radar altimeter is efficient and the echo wave model could be used to describe its return wave.The conventional return wave simulation is also presented simultaneously to compare with echo wave of synthetic aperture radar altimeter.Another conclusion is that synthetic aperture radar altimeter may reveal wave direction from simulation result of some sea status.