Calibration of geophone and hydrophone pairs

A method of performing a seismic survey in a marine environment using a seismic data acquisition system, comprising:

• providing a seismic data acquisition system disposed on a seabed of the marine environment;
• acquiring, by a geophone of the seismic data acquisition system, geophone trace data responsive to an acoustic signal propagated from an acoustic source;
• acquiring, by a hydrophone of the seismic data acquisition system, hydrophone trace data responsive to the acoustic signal propagated from the acoustic source;
• selecting, by a calibration component executed by one or more processors of a data processing system, from the geophone trace data, first seismic data within a first frequency band;
• selecting, by the calibration component, from the hydrophone trace data, second seismic data within the first frequency band;
• generating, by the calibration component, first phase shifted seismic data by applying a first phase shift to the first seismic data,
• generating, by the calibration component, second phase shifted seismic data by applying a second phase shift to the first seismic data, the second phase shift different from the first phase shift;
• generating, by the calibration component, a first upgoing wavefield based on a sum of the first phase shifted seismic data and the second seismic data;
• generating, by the calibration component, a second upgoing wavefield based on a sum of the second phase shifted seismic data and the second seismic data;
• generating, by the calibration component, a first downgoing wavefield based on a difference of the first phase shifted seismic data and the second seismic data;
• generating, by the calibration component, a second downgoing wavefield based on a difference of the second phase shifted seismic data and the second seismic data;
• determining, by the calibration component, a first ratio of the first upgoing wavefield and the first downgoing wavefield;
• determining, by the calibration component, a second ratio of the second upgoing wavefield and the second downgoing wavefield;
• and
• selecting, by the calibration component, the first phase shift based on the first ratio being greater than the second ratio to produce a calibrated image that compensates for a coupling of the geophone to earth.