Comparison of airgun clusters

Last year, Vaage, Strandenes & Metselaar [1] reported results from measurements of several symmetrical two gun clusters with varying separation distance, depth, firing pressure and source type. The source-types involved were Bolt 600 C airguns with volumes 10, 20 and 40 cu. inch, Sleeve airguns with volumes 10, 40, 70 and 150 cu. inch and Bolt Combo airguns with volumes 10, 40 and 90 cu. inch. It was found that the optimal gun separation in asymmetrical two gun cluster, based on this database, was 2.4 times the equilibrium radius, that the improvement in primary/bubble ratio on the average was a factor of 2.4 times the ratio for two corresponding non interacting guns and that the loss in primary peak amplitude at the optimal distance was 15 %.