Netherlands Organisation for Applied Scientific Research, P.O. Box 96864, 2509 JG, The Hague, Netherlands.
J Acoust Soc Am. 2013 Nov;134(5):3506-12. doi: 10.1121/1.4823804.
Passive acoustic monitoring with a single hydrophone has been suggested as a cost-effective method to monitor population density of echolocating marine mammals, by estimating the distance at which the hydrophone is able to intercept the echolocation clicks and distinguish these from the background. To avoid a bias in the estimated population density, this method relies on an unbiased estimate of the detection range and therefore of the propagation loss (PL). When applying this method, it is common practice to estimate PL at the center frequency of a broadband echolocation click and to assume this narrowband PL applies also to the broadband click. For a typical situation this narrowband approximation overestimates PL, underestimates the detection range and consequently overestimates the population density by an amount that for fixed center frequency increases with increasing pulse bandwidth and sonar figure of merit.
被动声学监测（使用单个水听器）已被提议作为一种经济有效的方法来监测回声定位海洋哺乳动物的种群密度，通过估计水听器能够拦截回声定位点击的距离，并将这些与背景区分开来。为了避免在估计种群密度时出现偏差，这种方法依赖于对检测范围（即传播损耗（PL））的无偏估计。在应用这种方法时，通常的做法是在宽带回声定位点击的中心频率处估计 PL，并假设这种窄带 PL 也适用于宽带点击。对于典型情况，这种窄带近似会高估 PL，低估检测范围，从而高估种群密度，而且对于固定的中心频率，种群密度的高估量随着脉冲带宽和声纳品质因数的增加而增加。
