Warner Graham A, Dosso Stan E, Hannay David E, Dettmer Jan
School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty Road, Suite 405A, Victoria, British Columbia V8P 5C2, Canada.
JASCO Applied Sciences, 2305-4464 Markham Street, Victoria, British Columbia V8Z 7X8, Canada.
J Acoust Soc Am. 2016 Jul;140(1):20. doi: 10.1121/1.4954755.
This paper estimates bowhead whale locations and uncertainties using non-linear Bayesian inversion of their modally-dispersed calls recorded on asynchronous recorders in the Chukchi Sea, Alaska. Bowhead calls were recorded on a cluster of 7 asynchronous ocean-bottom hydrophones that were separated by 0.5-9.2 km. A warping time-frequency analysis is used to extract relative mode arrival times as a function of frequency for nine frequency-modulated whale calls that dispersed in the shallow water environment. Each call was recorded on multiple hydrophones and the mode arrival times are inverted for: the whale location in the horizontal plane, source instantaneous frequency (IF), water sound-speed profile, seabed geoacoustic parameters, relative recorder clock drifts, and residual error standard deviations, all with estimated uncertainties. A simulation study shows that accurate prior environmental knowledge is not required for accurate localization as long as the inversion treats the environment as unknown. Joint inversion of multiple recorded calls is shown to substantially reduce uncertainties in location, source IF, and relative clock drift. Whale location uncertainties are estimated to be 30-160 m and relative clock drift uncertainties are 3-26 ms.
本文利用在阿拉斯加楚科奇海异步记录仪上记录的北极露脊鲸模态分散叫声，通过非线性贝叶斯反演来估计北极露脊鲸的位置及不确定性。北极露脊鲸的叫声是在一组7个异步海底水听器上记录的，这些水听器相距0.5 - 9.2千米。采用一种时频扭曲分析方法，从在浅水环境中分散的9个调频鲸鱼叫声中提取相对模态到达时间作为频率的函数。每个叫声在多个水听器上被记录，对模态到达时间进行反演以获取：鲸鱼在水平面上的位置、声源瞬时频率（IF）、水体声速剖面、海底地球声学参数、记录仪相对时钟漂移以及残余误差标准偏差，所有这些都带有估计的不确定性。一项模拟研究表明，只要反演将环境视为未知，准确的先验环境知识对于精确定位并非必需。对多个记录叫声进行联合反演可大幅降低位置、声源IF和相对时钟漂移的不确定性。估计鲸鱼位置的不确定性为30 - 160米，相对时钟漂移的不确定性为3 - 26毫秒。
