Patent attributes
A method of determining a vertical component of particle velocity from seismic data acquired using at least one receiver disposed within a water column comprises determining the vertical component of particle velocity from the pressure at a first location and a second location. The first location is the location of a first receiver, and is vertically beneath the second location. The method uses an operator accurate for seismic data acquired at a vertical separation between the first and second locations of up to at least 0.4 times the minimum wavelength of seismic energy used to acquire the seismic data. The second location may be at or above the surface of the water column. Alternatively, the method be applied to a twin streamer seismic surveying arrangement in which the second location is below the surface of the water column and is the location of a second receiver.