深海不平海底对声场水平纵向相关性的影响

发布时间：2018-05-02 11:52

本文选题：射线声学 + 次声学　；参考：《声学学报》2016年05期

【摘要】：海底地形变化对与海底作用的声反射区声场空间相关性有重要影响。利用南中国海某深海海域的一次声学实验数据,对深海海底反射区的声场空间相关性进行了分析。实验观测到,在距离声源约29 km至35 km距离范围处,不平海底环境下的水平纵向相关性出现了一些不同于平坦海底环境下的振荡结构,利用射线声学理论分析并解释了这两种不同海底环境产生水平纵向相关差异的原因。结果表明,在深海平坦海底方向一次海底反射到达区,对声场起主要贡献的经过一次海底反射声线间的到达时间差随着水平距离的增加而逐渐减少,从而干涉叠加后的相位差在[0,2π]内发生周期性变化,导致该区域声场的水平纵向相关性随着间距增加呈周期性振荡现象;而不平海底方向的海底小山丘恰对一次海底反射声线的阻挡影响,不仅使得与平坦海底方向相同区域的声传播损失明显增大,而且由于相对更多的本征声线路径的复杂多途干涉,该区域水平纵向相关性不再呈现明显的振荡周期,相关系数也有所下降。研究结果对于分析在深海复杂海底地形环境下的声呐阵列探测性能具有重要意义。
[Abstract]:The variation of submarine topography has an important influence on the spatial correlation of acoustic field in the acoustic reflection region. Based on the acoustic experimental data of a deep sea area in the South China Sea, the spatial correlation of acoustic field in the deep sea reflection zone is analyzed. It has been observed experimentally that in the range of 29 km to 35 km from the sound source, there are some oscillatory structures in the horizontal longitudinal correlation under the uneven seabed environment, which are different from those in the flat seabed environment. The reasons for the horizontal longitudinal correlation between these two different seabed environments are analyzed and explained by means of ray acoustics theory. The results show that the time difference of arrival between the acoustic lines which contribute to the sound field is gradually decreased with the increase of horizontal distance in the area of a sea bottom reflection in the direction of deep sea flat seabed. Therefore, the phase difference after interference superposition changes periodically in [0 ~ 2 蟺], which causes the horizontal and longitudinal correlation of sound field in this region to oscillate periodically with the increase of spacing. However, the blocking effect of a small submarine hill with uneven undersea direction on a sea floor reflected sound line not only increases the sound propagation loss in the same area as the flat sea floor direction, but also increases the sound propagation loss in the same area as the flat sea floor. Moreover, because of more complex multipath interference of intrinsic sound path, the horizontal and longitudinal correlation of the region no longer presents an obvious oscillation period, and the correlation coefficient also decreases. The results are of great significance to the analysis of sonar array detection performance in the deep sea complex seabed terrain environment.
【作者单位】：中国科学院声学研究所声场声信息国家重点实验室;中国科学院大学;中国科学院声学研究所南海研究站;
【基金】：国家自然科学基金项目(11434012,41561144006,11174312,11404366)资助
【分类号】：P733.2

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