Far field signature determination

A non-transitory machine-readable medium storing instructions executable by a processing resource to:

• determine, based on a sea surface state during each of a plurality of actuations of a plurality of sources of a source array, a coherent portion and an incoherent portion of a reflection coefficient of the sea surface;
• determine a notional source signature for each of the plurality of sources of the source array based on the coherent portion and the incoherent portion;
• and
• determine a far field signature of the source array at a particular location by propagating and summing the notional source signatures at the particular location.

A system, comprising:

• an averaging engine to average received near field data associated with each of a plurality of sources within a source array over a line;
• a first coherency engine to determine a coherent portion of a reflection coefficient of a sea surface associated with the source array;
• a second coherency engine to determine an incoherent portion of a reflection coefficient of the sea surface associated with the source array;
• a notional engine to determine a notional source signature for each of the plurality of sources based on the averaged near field data, the coherent portion, the incoherent portion, and a root mean square (RMS) of a depth variation relative to a nominal depth over the line;
• a determination engine to determine a far field signature of the source array based on the notional source signatures.

A method to manufacture a geophysical data product, the method comprising:

• obtaining geophysical data, wherein obtaining the geophysical data comprises:
• receiving data associated with a sea surface state;
• determining a coherent portion and an incoherent portion of a reflection coefficient of the sea surface based on the received data;
• determining a notional source signature of each source of a source array based on the coherent portion, the incoherent portion, and near field data associated with each of the sources;
• and
• determining a far field signature of the source array based on the notional source signatures of each of the sources;
• processing the geophysical data to generate a seismic image;
• and
• recording the geophysical data on one or more non-transitory machine-readable media, thereby creating the geophysical data product.