Foliage echoes:: A probe into the ecological acoustics of bat echolocation
Foliage echoes:: A probe into the ecological acoustics of bat echolocation
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DOI：
10.1121/1.429617
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发表时间：
2000-08-01
影响因子：
2.4
通讯作者：
Kuc, R
中科院分区：
文献类型：
--
作者：
Müller, R;Kuc, R
这里报道的研究旨在根据蝙蝠的自然输入（生态声学）的特性来了解蝙蝠的生物声纳系统。来自树叶的回声被作为无处不在的自然目标的例子进行研究。描述了回波特性及其与植物结构的定性关系。人们发现这些回波具有极大的随机性，并且通常既不是高斯分布也不是静止的。因此，对于区分此类目标类别有用的特征将仅限于估计的随机过程参数。识别了几个这样的统计信号特征，这些特征足够不变以允许对所使用的示例植物进行分类：振幅分布的α稳定模型的特征指数和色散、定义为最大平方振幅和信号能量之比的波峰因数、第一阈值通道分布的色散、相关矩阵的结构以及声音通道增益的非平稳性。通过成对组合特征可以降低判别错误概率。最佳组合是时变声道增益的对数线性模型的波峰因数和相关系数；对于从不同视图汇集的数据，其估计贝叶斯风险为 6.9%。 (C) 2000 年美国声学学会。 [S0001-4966(00)01808-7]。
The research reported here aims at understanding the biosonar system of bats based on the properties of its natural inputs (ecological acoustics). Echoes from foliages are studied as examples of ubiquitous, natural targets. The echo properties and their qualitative relationship to plant architecture are described. The echoes were found to be profoundly stochastic and in general neither Gaussian nor stationary. Consequently, features useful for discrimination of such target classes will be confined to estimated random process parameters. Several such statistical signal features which are sufficiently invariant to allow a classification of the used example plants were identified: the characteristic exponent and the dispersion of an alpha-stable model for the amplitude distribution, a crest factor defined as the ratio of maximum squared amplitude and signal energy, the dispersion of the first threshold passage distribution, the structure of the correlation matrix, and a nonstationarity in sound channel gain. Discrimination error probability could be reduced by combining features pairwise. The best combination was the crest factor and the correlation coefficient of a log-linear model of the time-variant sound channel gain; it yielded an estimated Bayes risk of 6.9% for data pooled from different views. (C) 2000 Acoustical Society of America. [S0001-4966(00)01808-7].