Reduction of sideswipe noise from seismic data by null steering

A method of determining the dip of unwanted out-of-plane energy contributions to seismic survey data obtained in a seismic line of profile by at least one seismic receiver in response to a seismic source along the profile line in a plane generally normal to the surface of the earth, comprising the steps of:

• (a) recording the seismic data collected from a seismic receiver geometry comprising receivers in-plane with the line of profile and receivers out-of-plane with the line of profile;
• (b) ordering the data in cross-line order in which seismic events along the line of profile are aligned in time and out-of-plane energy takes the form of a series of sawtoothed seismic events arriving at different times in the different lines of receivers;
• and
• (c) forming a display of the common offset gathers or shot records so that out-of-plane energy, if present, may be identified by the presence of sawtoothed seismic events arriving at different times across the out-of-plane receivers.