Development of autonomous acoustic observation system using click sounds emitted by small cetacean and field experiments

在这项研究中，我们提出了一个先进的自主声学观测系统，使用小齿鲸类物种，如伊洛瓦底江海豚和恒河海豚发出的咔哒声。这些物种由于人类活动造成的环境变化而濒临灭绝。了解它们的数量和水下行为对于研究保护它们的方法非常重要，因此我们开发了多水听器阵列系统，可以使用LBL系统和SBL系统检测它们的点击源位置并记录它们。从而实现了海豚的半实时三维定位。然后，通过离线分析数据，我们可以识别海豚的更详细的位置和生物声纳特征，以了解它们的水下行为。在测试了属于Odontoceti物种并栖息在日本沿海地区的江豚之后，我们于2006年1月将其带到印度。这次访问的目的是观察伊洛瓦底江海豚， ...更多信息 其中100只栖息在印度奥里萨邦的奇利卡湖。我们与德里的印度理工学院、CDA（Cilika发展管理局）和世界自然基金会印度分会合作，将该阵列部署到湖泊并记录点击数据。我们成功地实现了一些海豚的轨迹在半实时。基于这一结果，世界自然基金会印度分会已同意将该系统应用于恒河海豚调查。我们对2005年12月在奥里萨邦Budhabalanga河上游发现的恒河海豚进行了实验。根据资料，阐明了恒河海豚的特殊特征，如极窄的波束图（12°）。然后，我们在2007年2月在德里郊区的纳罗拉的恒河进行了初步实验。预期我们将发展一套坚固而紧凑的声学系统，以供恒河海豚调查之用，并适用于恶劣的河流环境。在伊洛瓦底江海豚调查中，我们开发了一种用于长期监测的自主真实的声学系统原型，该系统由水上基地和陆地基地组成。2007年1月开始施工和监测。我们得出的结论是，应该建立更具体的观测站和通信网络的基础设施，如互联网系统，开发一个新的监测系统，可以连接什么是在湖下发生的真实的时间与世界。少

In this research, we proposed an advanced autonomous acoustic observation system using click sounds emitted by small Odontoceti species such as the Irrawaddy dolphin and the Ganges river dolphin. These species are endangered because of environmental change due to human activities. Understanding their population and underwater behavior is important to examine the methods to preserve them, so that we developed the multi-hydrophone array system which can detect their location of clicks source using LBL system and SBL system and record them. Thus, we can achieve dolphin's 3D-locationos in semi-real time. Then, by analyzing the data in off-line, we can identify more detailed location and bio-sonar characteristics of dolphins to know their underwater behaviorAfter testing the array targeting the finless porpoise which belongs to Odontoceti species and inhabits Japanese costal area, we brought it to India in January, 2006. Purpose of the visit is to observe the Irrawaddy dolphin, approximatel … More y 100 numbers of which inhabit in Chilika Lake in Orissa state in India. Collaborating with Indian Institute of Technology, Delhi, CDA (Cilika Development Authority) and WWF-India, we deployed the array to the Lake and recorded clicks data. We succeed in achieving some dolphins trajectories in semi-real time. Based on this result, WWF-India has agreed to apply the system to Ganges river dolphin survey. We made experiments on an isolated Ganges river dolphin which was found at the upper stream of Budhabalanga river in Orissa state in December 2005. From data, Ganges river dolphin's special characteristics such as very narrow beam pattern (12°) have been claritied. Then, we made preliminary experiments in Ganges river in February 2007, in Narora on the outskirts of Delhi. It is expected that we will develop a robust and compact acoustic system for Ganges river dolphin survey, which is suitable for the harsh river environment. In regard to Irrawaddy dolphin survey, we have developed a proto-type of autonomous real time acoustic system for a long term monitoring which consists of a water base and a land base. Construction and monitoring started in January 2007. We came up with conclusion that more concrete observatories and infrastructure for communication networks such as internet system should be constructed to develop a new monitoring system which can connect what is happening under the lake with the world in real time. Less