Method for reducing inline directivity of air-gun source signature by optimizing spatial distribution of air-guns

A method for reducing inline directivity of an air-gun source signature by optimizing a spatial distribution of air-guns, comprising:

• for an air-gun array, setting a constraint condition in which a spacing between adjacent air-guns and a horizontal spacing between adjacent air-guns satisfy a preset range, and setting an objective function based on the spatial distribution of the air-guns;
• in a vertical plane, determining a maximum of the objective function by changing an inline location and a depth location of each single air-gun, obtaining inline locations and depth locations of air-guns corresponding to the maximum of the objective function, as an optimized air-gun array;
• and
• setting different firing times for air-guns at different depths in the optimized air-gun array, to align downgoing primaries of air-guns at different depths to reduce an inline directivity of the air-gun source signature.