中文摘要：

本文主要讨论浅海水平不变波导中的低频声传播问题，为环境适配声纳设计奠定基础。通过仿真分析了海水及海底环境参数对传播损失的影响，根据仿真及实验结果，建立了声速剖面随机扰动及海面、海底起伏条件下的声强分布概率模型，并利用模型中的形状参数α和尺度参数β，提出了局部蒙特卡洛模拟加曲线拟合的声场敏感性分析方法。仿真及实验结果表明声场传播损失服从伽马分布，良好水文条件下10km距离的声场能量起伏也达到10dB，随着距离增加，声场敏感性增加。本文所提出方法通过对近场声场的测量和统计实现对远场声场敏感性的预报，与全声场蒙特卡洛模拟相比计算量减小一个数量级。

英文摘要：

Low-frequency sound propagation through range-independent waveguide in shallow water, which lays the foundation for environment adapted sonar design, was discussed in the present work. Impacts of environmental parameters （i.e. seawater and seabed quality） on transmission loss were analyzed through simulation. The probability model of intensity distribution in conditions of random sound-speed perturbations, rough sea surface and bottom was established according to simulation and experimental results. Using shape parameter a and scale parameter β in model, a sensitivity analysis method by local Monte Carlo simulation plus curve fitting was proposed. Experimental measurements and simulation results suggest that transmission loss obeys the gamma distribution. Energy fluctuation reaches the level of 10 dB at the distance of 10 kilometer for favorable hydrological conditions, and the acoustic field sensitivity increases as the distance increases. The proposed method forecasts far-field sensitivity by near-field measurements and statistics, its calculation complexity is an order of magnitude less than that of global Monte Carlo simulation.