Observations and Bayesian location methodology of transient acoustic signals (likely blue whales) in the Indian Ocean, using a hydrophone triplet
- Author(s)
- Ronan Le Bras, Heidi Kuzma, Victor Sucic, Götz Bokelmann
- Abstract
A notable sequence of calls was encountered, spanning several days in January 2003, in the central part of the Indian Ocean on a hydrophone triplet recording acoustic data at a 250 Hz sampling rate. This paper presents signal processing methods applied to the waveform data to detect, group, extract amplitude and bearing estimates for the recorded signals. An approximate location for the source of the sequence of calls is inferred from extracting the features from the waveform. As the source approaches the hydrophone triplet, the source level (SL) of the calls is estimated at 187 ± 6 dB re: 1 μPa-1 m in the 15-60 Hz frequency range. The calls are attributed to a subgroup of blue whales, Balaenoptera musculus, with a characteristic acoustic signature. A Bayesian location method using probabilistic models for bearing and amplitude is demonstrated on the calls sequence. The method is applied to the case of detection at a single triad of hydrophones and results in a probability distribution map for the origin of the calls. It can be extended to detections at multiple triads and because of the Bayesian formulation, additional modeling complexity can be built-in as needed.
- Organisation(s)
- Department of Meteorology and Geophysics
- External organisation(s)
- CTBTO Preparatory Comission, Chatelet Resources LLC, University of Rijeka
- Journal
- Journal of the Acoustical Society of America
- Volume
- 139
- Pages
- 2656-2667
- No. of pages
- 12
- ISSN
- 0001-4966
- DOI
- https://doi.org/10.1121/1.4948758
- Publication date
- 05-2016
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105126 Applied geophysics, 105122 Seismic, 105102 General geophysics, 105124 Tectonics
- Keywords
- ASJC Scopus subject areas
- Arts and Humanities (miscellaneous), Acoustics and Ultrasonics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/b0996866-b5b6-4308-90fa-fdad92c0cdc5