Beamlet domain premigration deghosting on variable depth streamer seismic data

Local space and local wavenumber domain (beamlet domain) deghosting method is proposed in this work. Local Cosine Transform (LCT) is applied to the spatial axes of the frequency domain seismic data, and deghosting is achieved in each local spatial window which is defined by the LCT. In each window, different depth reference can be selected for the deghosting operator, which can adopt to the depth change of variable depth streamer. This method also avoids the long Fourier transform on spatial axes. The effectiveness has been validated by preliminary 2D tests on variable streamer synthetic seismic data.