Patent ID: 7768869

Claim:
A computer readable medium with a computer program stored thereon, the program having logic operable to cause a programmable computer to perform steps to provide a more accurate representation of earth's subsurface, comprising: decomposing seismic data representative of structures and composition of subsurface earth formations acquired using sensors that generate signals in response to seismic energy and that measure the same parameter at two water depths over the location of the subsurface earth formations into upgoing and downgoing pressure wavefield components, said upgoing pressure wavefield component being a deghosted wavefield; determining a substantially multiple-free vertical particle velocity wavefield from the decomposed pressure wavefield components, independently of knowledge of the source wavelet, wherein the substantially multiple-free vertical particle velocity wavefield is a reflected up-going wavefield at the sensors that would occur in the hypothetical absence of the water surface; determining a substantially multiple-free pressure wavefield from the substantially multiple-free vertical particle velocity wavefield; and inferring the structures of and compositions of the subsurface earth formations to provide a more accurate representation of the earth's subsurface, using the substantially multiple-free pressure wavefield.