千岛湖复杂地形条件下传播损失的估计与现场测量

湖区、港口近海、多山浅海等复杂地形条件下声传播建模难度大、距离相关的逐点测量过程复杂，本文提出使用UUV（Unmanned Underwater Vehicle）平台进行现场测量，其具有机动性强、快速高效等优点。本文使用统计学方法来处理湖试实验数据，同时用BELLHOP模型对信道仿真建模并估计传播损失参数。对比发现，当声源在恒温层时仿真与实测相符，在负梯度层时相差较大，主因在于湖区地形和底质的复杂多变导致触底声波的折射与吸收难以估计。实验说明复杂地形环境中传播损失的估计仍需依赖现场测量，而使用UUV平台的快速测量法是一种高效可靠手段。 

Estimation and field measurment of the transmission loss under complex terrain conditions of the Qiandao lake

As we known, to simulate and measure the sound Transmission Loss (TL) in complex terrain environment such as lake, coastal port and mountainous shallow water face a lot of difficulties. We propose to measure the TL by using UUV platform which may bring with advantages of good maneuverability and efficiency. The data of lake experiments are handled with statistical methods. Meanwhile, the transmission models are simulated by BELLHOP to estimate the TL of experiments. When the source is placed in thermostat layer, the simulation agrees well with the measurement. However, when it is placed in negative gradient layer, the simulation is not corresponding to the measurement. By comparison, it is mainly because of the complex terrain and sediment of lake Bottom, which leads to difficulties of estimation on sound wave refraction and absorption. The experiments declared that field measurement have to be employed in this case, and the proposed method using UUV is proved to be more efficient and reliable.