| 摘要 |
This disclosure is directed to wavefield separation methods and systems. In one aspect, methods and systems compute an approximate vertical particle velocity wavefield based on a measured pressure wavefield and knowledge of a free-surface of a body of water when the pressure wavefield was measured. Forward and backward extrapolated gathers are computed based on a pressure wavefield gather for each trial depth of a series of trial depths of the body of water. For each trial depth, a set of maximum energy differences for each time window of a series of time windows applied to the extrapolated gathers may be computed. For each window, a peak energy may be computed from the sets of maximum energy differences computed for each depth. The extrapolated gathers are used to compute 2301 an approximate frozen free-surface profile. The approximate frozen free-surface profile and the measured pressure wavefield are used to compute 2306 an approximate vertical particle velocity wavefield. The approximate vertical particle velocity wavefield and measured pressure wavefield is used to compute one of separate up-going and down-going vertical particle velocity wavefields. |
