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为了获取海底沉积物的物理和地声特性,根据等效密度流体近似反射模型得到的不同掠射角下的海底反射损失,利用差分进化算法和粒子群算法相结合的两级混合优化算法以及Bayesian反演方法对海底沉积物的孔隙度、平均颗粒粒度、颗粒质量密度以及颗粒体积弹性模量进行反演,再根据这4个物理参数的估计值进一步计算出海底地声参数,包括声速和衰减。通过反演结果与仿真真值的比较可以看出,除颗粒体积弹性模量外,得到的估计结果是令人满意的,特别是这种间接反演海底地声参数的方法对地声参数的估计具有较高的精确性和较强的稳健性,相对误差分别为0.092%和17%。最后,对实验室水池池底沙质沉积物的反射损失数据进行处理,给出了沙质沉积物各参数的估计值、不确定性和相关性,并通过反演结果与部分实测参数值的比较验证了反演方法的可行性。
In order to obtain the physical and geophone characteristics of seafloor sediment, based on the reflection loss of seafloor at different grazing angles obtained from the approximate reflection model of equivalent density fluid, a two-level hybrid optimization algorithm based on differential evolution algorithm and particle swarm optimization algorithm and Bayesian The inversion method inverts the porosity, average particle size, particle mass density, and bulk modulus of the seabed sediments. Based on these four physical parameter estimates, the seabed ground acoustic parameters are further calculated, including the sound velocity and attenuation . By comparing the inversion results with the simulation truth values, we can see that the estimated results except for the bulk modulus of particles are satisfactory, especially the method of indirect inversion of submarine ground acoustic parameters The estimates are of high accuracy and robustness with relative errors of 0.092% and 17%, respectively. Finally, the data of reflection losses of sandy sediments at the bottom of the pool in the laboratory are processed, and the estimated values, uncertainties and correlations of various parameters of sandy sediments are given. Based on the results of inversion and some measured values The feasibility of inversion method is verified by comparison.