Proceedings ArticleDOI
Development of AUV-based system for acoustic tracking of diving sperm whales
Tamaki Ura,Rajendar Bahl,M. Sakata,Junichi Kojima,Tetsuo Fukuchi,J. Ura,K. Mori,Takeshi Nakatani,Y. Nose,Harumi Sugimatsu +9 more
- Vol. 4, pp 2302-2307
TLDR
In this paper, the authors used an AUV as an observation platform for sperm whales to detect sperm whale clicks and track them by listening to their clicks using a set of 4-hydrophone arrays.Abstract:
Sperm whales are known to dive to a depth of over two thousand meters. They emit loud impulsive broadband sounds called "clicks" during their diving. To investigate the sperm whale behavior, we attempt to apply the autonomous underwater vehicle (AUV) as an observation platform for sperm whales. AUV recognizes sperm whales individually and tracks them by listening to their clicks. As an initial stage for these objectives, we set up an experiment to test our observation system using two boats without an AUV. The observation system consists of two sets of 4-hydrophone arrays. Each hydrophone array works as a short baseline (SBL) system. The SBL system detects sperm whale clicks and calculates the orientation to sperm whales. Two relative directions from the two SBL arrays separated over a long base line (LBL) tell us the position of whale by triangulation. In the middle of August 2003, we carried out an experiment of the test system off Chichijima Island in Ogasawara. We deployed two boats each with a hydrophone array. An acoustic link between the SBL arrays was established to obtain the LBL length. During the experiments over five days we encountered at least fourteen sperm whales and succeeded in tracking some sperm whales by our observation system. Later in September 2004, we will perform another experiment using an AUV that works as one of the SBL systems. We expect this AUV-based observation system will give us a better understanding of sperm whale diving behavior and eco-systemread more
Citations
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Journal ArticleDOI
Localization of sperm whales in a group using clicks received at two separated short baseline arrays.
Ryo Hirotsu,Masao Yanagisawa,Tamaki Ura,M. Sakata,Harumi Sugimatsu,Junichi Kojima,Rajendar Bahl +6 more
TL;DR: The proposed sperm whale click analysis scheme is able to localize the positions of the whales in a group using data received at two arrays deployed near the surface using the three-dimensional underwater trajectories of six sperm whales.
Separation of Sperm Whale Click-Trains for Multipath Rejection and Localization
TL;DR: In this article, an algorithm is described for separation and grouping of sperm whale clicks received at a single hydrophone, where the clicks are separated into click-trains from separate animals and separate propagation paths.
Journal ArticleDOI
Separation of sperm whale click-trains for multipath rejection
TL;DR: An algorithm is described for grouping sperm whale clicks received at a single hydrophone into click-trains associated with a given whale and propagation path, showing the elimination of time-delay ambiguities associated with the reverberation paths observed at sensor pairs.
Dissertation
Design and experimental evaluation of an Autonomous Surface Craft to support AUV operations
TL;DR: Tide et al. as mentioned in this paper used an Autonomous surface craft (ASC) with a wet bay from which to launch an AUV, including a launch capability, and used a towed underwater modem to increase the communication range over two kilometers.
Journal ArticleDOI
Whale rover moving along the surface of sperm whale
TL;DR: A novel roving biologger or whale rover that travels along a sperm whale's body surface from its back to its mouth area using robotic technology is proposed and further improved the whale rover design to allow for adapted travel on curved or uneven surfaces.
References
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Journal ArticleDOI
A digital acoustic recording tag for measuring the response of wild marine mammals to sound
Mark Johnson,Peter L. Tyack +1 more
TL;DR: In this paper, a novel archival tag, called the DTAG, has been developed to monitor the behavior of marine mammals, and their response to sound, continuously throughout the dive cycle.
Journal ArticleDOI
The monopulsed nature of sperm whale clicks
TL;DR: On-axis click properties support previous work proposing the nose of sperm whales to operate as a generator of sound.
Journal ArticleDOI
Sperm whale sound production studied with ultrasound time/depth-recording tags.
TL;DR: Shared click features suggest that sound production in sperm whales is based on the same fundamental biomechanics as in smaller odontocetes and that the nasal complexes are therefore not only anatomically but also functionally homologous in generating the initial sound pulse.
Journal ArticleDOI
Time and frequency domain characteristics of sperm whale clicks
John Goold,S.E. Jones +1 more
TL;DR: The frequencies at which the multiples emerge in male and female clicks supports the idea of air cavities in the sperm whale head acting as sound reflectors, although the magnitude of the second pulse at high frequencies suggests some form of off axis distortion.
Journal ArticleDOI
Vocal behavior of male sperm whales: Why do they click?
TL;DR: The results of this study suggest that usual clicks and creaks are both used for echolocation purposes, the former to gather information about acoustically reflective features and the latter to detect prey.