摘要
通过时频分析法从海底环境噪声数据中提取界面波频散曲线,进而采用非线性贝叶斯反演方法估算海底沉积物厚度、剪切波速度、压缩波速度和密度等参数及其不确定性。参数的最大后验概率(MAP)估计值和边缘概率分布分别通过自适应单纯形模拟退火法和Metropolis-Hastings采样法在各参数先验区间内搜索获得,采用贝叶斯信息准则(BIC)从不同参数化模型中选择最优模型。界面波频散曲线反演结果表明:满足实测数据的最优海底模型结构为3层均匀分布剪切波速度剖面结构,海底深度的反演精度在800m以内,比起压缩波速度和密度,剪切波速度的不确定性更小,对界面波频散曲线更敏感。
This paper applies a dataset of ocean ambient noise data to extract interface-wave dispersion curves using time-frequency analysis.The nonlinear Bayesian inversion is applied to estimate seabed sediment parameters such as thickness,shear-wave velocity,compression wave velocity and density,and their uncertainties from interface-wave dispersion curves.The maximum a posterior（MAP） model and marginal probability distributions of parameters are estimated using posterior probability densities computed by adaptive simplex simulated annealing and Metropolis-Hastings sampling methods.The Bayesian information criterion is applied to determine the optimal model that fully explains the observed data by the different parameterizations.The inversion results indicate that 3-uniform-layer model is chosen as the preferred parameterization.The resolution of inversion is up to 800 m-depth.The shear-wave velocity and layer thickness have fewer uncertainties and are more sensitive to the interface wave dispersion than the compression wave velocity and density.
出处
《声学学报》
EI
CSCD
北大核心
2012年第3期225-231,共7页
Acta Acustica
基金
国家科技重大专项(2011ZX05026-004-06)
国家高技术研究发展计划(2009AA093401)资助项目
