Abstract：High velocity resolution for shallow strata is needed during gas hydrate seismic data processing.Present velocity analysis algorithms mostly have certain limits and could not meet the requirements of high resolution and high precision.We improve the statistical phase-correlation velocity analysis algorithm by setting threshold value to limit concentration functions,which enhances the reliability of discriminating phase probability distribution of noise and signal in "R Test".We apply the improved algorithm in gas hydrate seismic data processing of the northern part in the South China Sea.It is proved that the resolution and precision of velocity spectrum calculated by this algorithm are improved,which leads velocity picking more easily.BSR is identified clearly in the stack sections and the improved algorithm could meet the requirements of gas hydrate seismic data processing.
