• journal_title：Geophysics
• Contributor：Richard E. Duren ; Stan V. Morris
• Publisher：Society of Exploration Geophysicists
• Date：1992-
• Format：text/html
• Language：en
• Identifier：10.1190/1.1443229
• journal_abbrev：Geophysics
• issn：0016-8033
• volume：57
• issue：12
• firstpage：1623
• section：Articles

Null steering refers to the removal (or zeroing) of interferences at specified dips by creating receiving patterns with nulls that are aligned on the interferences. This type of beamforming is more effective than forming a simple crossline array and can be applied to both multistreamer and swath data for reducing out-of-plane interferences (sideswipe, boat interference, etc.) that corrupt two-dimensional (2-D) data (the desired signal). Many beamforming techniques lead to signal cancellation when the interferences are correlated with the desired signal. However, a beamforming technique that has been developed is effective in the presence of signal correlated interferences. The technique can be effectively extended to prestack and poststack seismic data.The number of interferences and their dips are identified by a visual examination of the plotted data. This information can be used to design filters that are applied to the total data set. The resulting 2-D data set is free from the crossline interferences with the inline 2-D data remaining unaltered.Model and real data comparisons between null steering and simple crossline array summation show that: (1) null steering significantly attenuates crossline interference, and (2) 2-D inline data, masked by sideswipe, can be revealed once sideswipe is attenuated by null steering. The real data examples show the identification and effective attenuation of interferences that could easily be interpreted as inline 2-D data: (1) an apparent steeply dipping event, and (2) an apparent flat 'bright spot.'