Significant wave height (SWH) is one of the major ocean altimetry products. This paper proposes a fast algorithm in retrieving the SWH from altimeter waveform. The idea is to differentiate the echo waveform and acquire a Gaussian-shape waveform. Then the standard deviation of the Gaussian function is computed directly and the standard deviation of the scatter probability density function (hence, SWH) is retrieved. The performance of the algorithm is verified by Jason-2 altimeter data. This algorithm can be employed onboard or in the near-real-time processing in future altimeter missions.
