1. In a process for generating an image of a subterranean formation using marine seismic techniques in which pressure and particle motion wavefields reflected from the subterranean formation are measured by co-located pressure and particle motion sensors, the specific improvement comprising: computing a matching operator that relates the pressure sensor and the particle motion sensor responses of the co-located pressure and particle motion sensors based on pressure and particle motion wavefields; computing at least one of up-going pressure wavefield and up-going particle motion wavefield based on the matching operator and the measured pressure and particle motion wavefields; and using one of the up-going pressure wavefield and the up-going particle motion wavefield in generating an image of the subterranean formation without receiver ghost effects, thereby enhancing the image of the subterranean formation.