| 摘要 |
<p>One aspect provides a marine acoustic vibrator 100, comprising: an outer shell 104; and a variable gas flow restrictor 102 disposed within the outer shell; wherein the marine acoustic vibrator 100 has a resonance frequency selectable based at least in part on the variable gas flow restrictor. Another aspect relates to a method of towing an acoustic vibrator and restricting the gas flow in the vibrator to control a first resonant frequency. A further aspect relates to a marine vibrator with a flextensional outer shell, a fixture 109 and a driver 108 having two ends coupled to the shell and the fixture respectively. The value of the gas spring is changed by restricting gas flow in the vibrator. The vibrator may have at least two resonant frequencies at 10 Hz or lower when submerged in water at a depth of 0-300m. The gas flow restrictor may comprise a first and second plate with holes wherein the second plate is movable to at least partially cover the holes of the first plate.</p> |
