摘要
阐述准周期性随机声脉冲序列作为船舶噪声模型的普适性,侧重讨论船舶噪声准周期性随机声脉冲序列所产生的线谱经随机海洋信道传输后的变化。指出在大多数工况下,船舶噪声并不是以几种不同频率的加性正弦波直接叠加在宽带连续谱噪声上,而是一类本身并不含有任何有限强度加性正弦波分量的信号。研究结果表明:海洋信道多途效应引起船舶噪声脉冲序列信号时域上时延扩展;海洋信道的随机性使船舶噪声随机声脉冲序列信号准周期性下降,导致船舶噪声线谱相对幅度"额外"快速衰减,对于存在大范围不均匀水团的海洋信道,50 km传播距离上其介质随机起伏引起的船舶噪声线谱"额外"衰减最高可达11 dB。海洋信道随机性引起的船舶噪声线谱衰减不可忽视。
The universality of quasi-periodic random sound pulse sequence ship noise model is elaborated. The focus is on studying changes of line-spectra produced by quasi-periodic random sound pulse sequence after transmission in random inhomogeneous ocean channel. It is pointed out that under most working conditions, ship noise is not the superposition of several different frequency additive sine waves and the broadb and continuous spectrum noise directly, but is a kind of signal itself without containing any limited strength additivesinusoidal components. It is shown that the ocean channel multipath effect causes time delay extension of shipnoise pulse sequence signal, and the random inhomogeneity of the ocean channel makes the quasi-periodicity downturn of ship noise random sound pulse sequence signal,and can lead to ship noise line-spectrum ＂extra＂ attenuation. For the ocean channel with a wide range non-uniform watermass, the random inhomogeneity of water medium can cause ship noise line-spectrum ＂extra＂ attenuation of up to 11 dB on the propagation distance of 50 km
出处
《声学学报》
EI
CSCD
北大核心
2015年第2期170-177,共8页
Acta Acustica
基金
国家自然科学基金(11474301)
中国科学院声学研究所创新基金资助
