Location, Characterization and Quantification of Hydroacoustic Signals in the Indian Ocean

摘要

Data from three Indian Ocean hydroacoustic stations (Diego Garcia North, Diego Garcia South, and Cape Leeuwin) have been characterized and quantified for the calendar year 2002. These results were delivered in the form of a 2002 catalogue, and are briefly summarized here, with additional consideration of their significance in the overall station characterization. Background noise spectra for each station have been characterized for the entire year and show distinct seasonal variations, as well as station-to-station differences. For the most part, Garcia North is the quietest station, with Garcia South being slightly noisier, and Cape Leeuwin being the noisiest station. These observations in background noise variations help explain variations in some of the signals observed at each station. Quantification of observed signals show that ship noise is the most commonly observed signal at all three sites with a whale call being a frequent source of background signal. Airgunning is also observed at the three sites.