Method and device to deghost seismic data

An apparatus for processing seismic data related to a subsurface of a body of water to generate an image of the subsurface, that apparatus comprising:

• an interface configured to receive seismic data acquired using detectors disposed on a depth-varying profile;
• and
• a data processing unit connected to the interface and configured
• (i) to generate, from the seismic data,
• first traces (UP) that correspond to traces as recorded by the detectors and migrated to water surface, and
• second traces (DW) that correspond to traces as would be recorded by virtual detectors mirroring the detectors relative to the water surface and migrated to water surface,
• (ii) to generate (A) third traces (SYM) as a sum of corresponding ones among the first traces and the second traces, and (B) fourth traces (DBG) as a difference of the corresponding ones among the first traces and the second traces, and
• (iii) to deghost at least one of the first traces and the second traces using positive and negative polarity portions of the third traces and of the fourth traces.

A computer readable medium non-transitorily storing executable codes which when executed on a computer receiving seismic data acquired using detectors disposed on a depth-varying profile make the computer perform a seismic data processing method comprising:

• generating, from the seismic data,
• first traces (UP) that correspond to traces as recorded by the detectors and migrated to water surface, and
• second traces (DW) that correspond to traces as would be recorded by virtual detectors mirroring the detectors relative to the water surface and migrated to water surface;
• generating (A) third traces (SYM) as a sum of corresponding ones among the first traces and the second traces, and (B) fourth traces (DBG) as a difference of the corresponding ones among the first traces and the second traces;
• and
• deghosting at least one of the first traces and the second traces using positive and negative polarity portions of the third traces and of the fourth traces.