Naval Undersea Warfare Center, Division Newport, 1176 Howell Street, Newport, Rhode Island, USA.
J Acoust Soc Am. 2011 Feb;129(2):662-9. doi: 10.1121/1.3531844.
Passive acoustic detection is being increasingly used to monitor visually cryptic cetaceans such as Blainville's beaked whales (Mesoplodon densirostris) that may be especially sensitive to underwater sound. The efficacy of passive acoustic detection is traditionally characterized by the probability of detecting the animal's sound emissions as a function of signal-to-noise ratio. The probability of detection can be predicted using accepted, but not necessarily accurate, models of the underwater acoustic environment. Recent field studies combining far-field hydrophone arrays with on-animal acoustic recording tags have yielded the location and time of each sound emission from tagged animals, enabling in-situ measurements of the probability of detection. However, tagging studies can only take place in calm seas and so do not reflect the full range of ambient noise conditions under which passive acoustic detection may be used. Increased surface-generated noise from wind and wave interaction degrades the signal-to-noise ratio of animal sound receptions at a given distance leading to a reduction in probability of detection. This paper presents a case study simulating the effect of increasing ambient noise on detection of M. densirostris foraging clicks recorded from a tagged whale swimming in the vicinity of a deep-water, bottom-mounted hydrophone array.
被动声学探测技术正被越来越多地用于监测诸如柏氏中喙鲸（Mesoplodon densirostris）等视觉上隐蔽的鲸类，因为这些鲸类可能对水下声音特别敏感。被动声学探测的有效性传统上是通过信噪比函数来确定探测到动物声音排放的概率来描述的。可以使用公认的、但不一定准确的水下声学环境模型来预测探测概率。最近的现场研究结合了远场水听器阵和动物声学记录标签，得出了标记动物每次声音排放的位置和时间，从而能够对探测概率进行现场测量。然而，标记研究只能在平静的海况下进行，因此不能反映在被动声学探测可能使用的完整环境噪声条件范围内。风与浪相互作用产生的表面噪声增加，导致在给定距离处动物声音接收的信噪比降低，从而降低了探测概率。本文通过模拟深海底部安装的水听器阵附近游动的标记鲸鱼的觅食声记录，展示了环境噪声增加对柏氏中喙鲸探测的影响。
