Is it optimal to tow air guns shallow to enhance low frequencies
Is it optimal to tow air guns shallow to enhance low frequencies
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DOI：
10.1190/geo2013-0348.1
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发表时间：
2014-03
期刊：
影响因子：
3.3
通讯作者：
M. Landrø;L. Amundsen
中科院分区：
文献类型：
--
作者：
M. Landrø;L. Amundsen
ABSTRACTIn marine seismic acquisition, it used to be commonly accepted that it is optimal to tow the source deep to enhance the low-frequency content in the seismic data. However, Mayne and Quay found in 1971 that the low-frequency response of air guns actually improves as the source depth decreases. We evaluated a simple ad hoc theory that demonstrates that two effects are counteracting each other: The free-surface effect favors deep-towed sources, whereas the bubble time period (increasing with decreasing source depth) favors shallower tow depths. From a fjord test, we found that combining several source depths in an air gun array might flatten and improve the low-frequency part of the source spectrum. The experiment confirms that various source depths result in local, characteristic maxima in the low-frequency spectrum, corresponding to the bubble time period of the air gun.
