Device and method for deghosting variable depth streamer data

A computing device configured to de-ghost seismic data related to a subsurface of a body of water, the computing device comprising:

• an interface configured to receive seismic data recorded by a plurality of seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain and the seismic receivers are located at different depths (zr) in the body of water;
• a processor configured to generate migration data (du) and mirror migration data (dd) from the seismic data;
• the processor further configured to derive a ghost free model (m) based on simultaneously using the migration data (du) and mirror migration data (dd);
• the processor further configured to generate a deghosted dataset based on the ghost free model (m);
• and
• the processor further configured to use the deghosted dataset to generate a final image (f) of the subsurface.

A method for processing seismic data related to a subsurface of a body of water, the method comprising:

• receiving migration data (du) and mirror migration data (dd) generated from input seismic data recorded by a plurality of seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain and the seismic receivers are located at different depths (zr) in the body of water;
• deriving a first ghost lag model (τgu) corresponding to the migration data (du) that estimates a first ghost lag to a seismic source as a function of an offset h of each seismic receiver of the plurality of seismic receivers;
• deriving a second ghost lag model (τgd) corresponding to the mirrored migration data (dd) that estimates a second ghost lag to the seismic source as a function of an offset h of each seismic receiver of the plurality of seismic receivers;
• and
• processing the migration data (du) using the first and second ghost lag models to provide a final image (f) of the subsurface.