北极典型冰下声信道建模及特性

发布时间：2018-12-13 21:22

【摘要】：将Burke-Twersky(BT)散射模型与射线理论相结合研究北极典型冰下的水声信道特性。BT模型将极地冰水界面的冰脊视为随机分布在自由表面的半椭圆柱。首先根据BT模型分别对高频和低频情况下的冰面反射系数取近似,计算不同频率的冰面反射系数。然后结合射线理论计算冰下声场并分析冰下信道特性,并与相同条件下绝对软界面的水声信道进行对比研究。结果显示,由于冰界面的存在,冰水界面与绝对软界面相比,冰面反射系数较小,使得部分声线不会传播很远,且随频率的增加衰减越发严重,因此不利于声信号远距离传播;此外在信道结构上,由于冰层反射系数较小,冰下信道多径相较于无冰的水-空气界面其多途现象不明显。研究结果对认知极地冰下水声信道特性以及开展极地水声系统性能预报具有一定意义。
[Abstract]:The Burke-Twersky (BT) scattering model is combined with the ray theory to study the underwater acoustic channel characteristics of typical Arctic ice. The BT model regards the ice ridge of the polar ice interface as a semi-elliptic column randomly distributed on the free surface. Firstly, according to the BT model, the ice surface reflection coefficient at high frequency and low frequency is approximated, and the ice surface reflection coefficient with different frequency is calculated. Then the acoustic field under ice is calculated with ray theory and the characteristics of subglacial channel are analyzed and compared with the underwater acoustic channel with absolute soft interface under the same conditions. The results show that due to the existence of ice interface, the reflection coefficient of ice surface is smaller than that of absolute soft interface, which makes some sound lines not propagate far, and the attenuation becomes more and more serious with the increase of frequency, which is not conducive to the long distance propagation of acoustic signal. In addition, as the reflection coefficient of the ice layer is small, the multipath phenomenon of the subglacial channel is not obvious compared with the ice-free water-air interface. The results of the study are of significance to the understanding of underwater acoustic channel characteristics under polar ice and the performance prediction of polar underwater acoustic systems.
【作者单位】：哈尔滨工程大学水声技术重点实验室;哈尔滨工程大学水声工程学院;
【基金】：国家自然科学基金重点项目(61631008);国家自然科学基金项目(61471137) 水声技术重点实验室开放基金(SSKF201500203) 霍英东教育基金项目(151007) 中央高校基本科研业务费专项资金(heucfd1506,heucfx1505)资助
【分类号】：TB56

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