ASA 126th Meeting Denver 1993 October 4-8

4aUW10. Acoustic signatures of imploding underwater light bulbs.

William J. Marshall, Jr.

BBN Systems & Technol., Union Station, New London, CT 06320

Imploding light bulbs are sometimes used as underwater sound sources because they produce impulsive signals similar to small explosions, yet are cheaper and more convenient to procure, store, and use. On a recent sea trial, light bulb sources were used to measure the straightness of a bottom-mounted hydrophone array. For this purpose the sharp leading edge was the most important characteristic of the acoustic signature, however the test provided a good opportunity to record and study other signature features as well. Results for a moderate number of common household light bulbs are given. Data include statistics on crush depths, measured acoustic waveforms, and energy spectral levels, and correspondence between these observations and a simple theory of sound generation by imploding gas bubbles. This information should be useful to others planning acoustical tests using such sources. [Work sponsored by the Advanced Research Projects Agency.]