复杂声速剖面约束下的深海水层速度反演  

Velocity inversion of deep seawater under constraints of complicated acoustic channels

作　　者：高子傲 孙建国[1] GAO Ziao;SUN Jianguo(College of Geo-Exploration Science and Technology,Jilin University,Changchun 130026,China)

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026

出　　处：《世界地质》2022年第4期853-865,共13页World Geology

基　　金：国家重点研究发展计划(2019YFC0312004)。

摘　　要：为对复杂声速剖面进行反演,笔者采用速度分析建模与伴随状态法层析成像反演建模相结合的方法获得声速剖面沿垂向速度。采用Munk公式描述水层速度垂向变化,并引入随机声速剖面复杂速度建模。在此基础上,使用海底反射走时伴随状态法层析成像反演复杂声速剖面。将声速剖面较准确的速度分析结果作为初始迭代,通过求解伴随偏微分方程得到非线性目标函数的梯度,避免了对Fréchet导数的大量计算。较准确叠加速度初始模型的引入提高了迭代效率与计算精度。最终得到了与真实模型速度吻合的结果。In order to invert complicated acoustic channels,the authors use the velocity analysis modeling combined with the adjoint tomography modeling to obtain the vertical velocity of the acoustic channel.On the premise of using Munk formula to describe the vertical change of the water layer velocity,as well as introducing the stochastic velocity complicated modeling,the complicated acoustic channel is inverted by using the seabed reflection traveltime and adjoint tomography.By using the precise velocity analysis results of the acoustic channel as the initial iteration velocity,the gradient of the nonlinear objective function is obtained by solving the adjoint partial differential equation to avoid a large number of calculations of the Fréchet derivative.The introduction of the accurate superposition velocity initial model improves the efficiency of iteration and calculation accuracy.Finally,the results that are consistent with the real model velocity are obtained.

关 键 词：声速剖面 Munk公式 速度反演 伴随状态法层析成像 

分 类 号：P631.46[天文地球—地质矿产勘探]