Vertical Directionality of Low Frequency Ambient Noise in the South Fiji Basin

摘要

The vertical directionality of ambient noise has been measured at two sites in the South Fiji Basin for the frequency range 10-200 Hz. The results are compared with the depth dependence of omnidirectional data taken previously at the same location. (R. W. Bannister, J. Acoust. Soc. Am., Suppl. 1, 60, S20 (1976)). For frequencies above 100 Hz, the measured noise is uniformly distributed throughout the water column and is principally due to local wind generated noise. Below 100 Hz, there is an additional broad peak in level centered at the deep sound channel axis. This peak is apparently due to long range noise sources received via SOFAR propagation paths. An analysis of the standard deviation could not determine conclusively whether these distant noise sources were storms or ships.