Abstract: In order to solve the problem that the measuring ocean waves results of ocean wave spectrometer were effected by speckle noise and radar response function,an estimation method for speckle noise was proposed based on the test data obtained from ocean wave spectrometer in flight experiments. The parameters of the Gaussian function were estimated by using least square fitting algorithm to the experimental values of speckle noise and radar response function. Then the wave modulation spectrum was corrected, and effects of speckle noise and radar response function on measuring ocean wave results were given. The results show that, when applying the speckle noise correction, the mean significant wave height is decreased by 12%; and there would be a 2.9% underestimate of the mean significant wave height, if the radar response correction are not taken into account. Then it is proved that the speckle noise correction is essential if one wishes to estimate the physical quantities associated to the wave spectra, and the estimation method is effective.