Adaptive deghosting for a rough and dynamic sea surface

Abstract

The sea surface is a strong reflector that results in a ghost wavefield at the source and the detector side. Consequently, a interference pattern occurs in the wavenumber-frequency domain. For a flat sea surface deep notch areas in the spectrum appear where there is destructive interference. The SNR (signal-tonoise ratio) is low in these areas. A rough and dynamic sea surface affects the propagation of the ghost wavefields and will distort the notch areas. If a rough and dynamic sea surface is present it should be taken into account in the process of deghosting. When the rough and dynamic sea surface is neglected the estimated ghost-free data will contain more noise. Often there are no additional measurements available that provide the exact shape of the rough and dynamic sea surface to model its corresponding ghost effect. Therefore, we introduce an adaptive deghosting method that takes into account a rough and dynamic sea surface without any prior information of this sea surface.