文献类型：期刊文献

中文题名：基于经验正交函数的剖面重构及其物理意义分析

英文题名：Profile Reconstruction Based on Empirical Orthogonal Function and Its Physical Meaning Analysis

作者：钟玮琪[1];屈科[1];梁羿[1]

机构：[1]广东海洋大学电子与信息工程学院,广东湛江524088

年份：2022

卷号：41

期号：1

起止页码：57

中文期刊名：海洋技术学报

外文期刊名：Journal of Ocean Technology

收录：CSTPCD

基金：大学生创新训练资助项目(S202110566056)。

语种：中文

中文关键词：经验正交函数;声速剖面重构;投影系数

外文关键词：Empirical Orthogonal Function;reconstruction of sound speed profile;projection coefficients

中文摘要：为了降低声速剖面在水声学逆问题中未知参数的维度,通常将海洋声速剖面表示为恒定的背景剖面与扰动项的叠加,通过提取样本扰动的主成分,使用若干阶经验正交函数EOF和投影系数描述声速剖面。EOF作为一种数值统计方法,实质上是样本数据矩阵的特征,没有明确的物理意义。为了提升对EOF方法反演结果的解析,本文基于中美联合实验在南海北部测量的温度链数据对EOF系数扰动与海洋变化规律进行了讨论,分析第一、二阶投影系数所对应的物理意义和前两阶投影系数时间变化率与内波之间的联系。研究结果表明:一阶投影系数与等声速线扰动具有强相关;跃层梯度受到二阶模态控制;根据一个内孤立波动力学周期内的密度层扰动规律,可以通过双振荡结构识别内孤立波,相关的结果可以为声速剖面相关的反演提供参考。

外文摘要：In order to reduce the dimension of the unknown parameters of the sound speed profile in the inverse problem of underwater acoustics,the ocean sound speed profile is often expressed as the superposition of a constant background profile and a disturbance term.By extracting the principal components of the sample disturbance,several order empirical orthogonal functions(Empirical Orthogonal Function,EOF) and projection coefficients are used to describe the sound speed profile.As a numerical statistical method,EOF is essentially the characteristic of sample data matrix and has no clear physical meaning.In order to improve the analysis of the inversion results of the EOF method,based on the temperature chain data measured by The Asian Seas International Experiment in the northern part of the South China Sea,this paper discusses the disturbance of the EOF coefficient and the law of ocean variation,and analyzes the physical meaning of the first and second order projection coefficients and the relationship between the time change rate of the first two order projection coefficients and internal waves.The results show that there is a strong correlation between the first-order projection coefficient and the equal sound velocity line.The thermocline gradient is controlled by second-order modes.According to the density of a solitary wave mechanics within the cycle layer disturbance,to identify internal solitary wave through double oscillation structure.Relevant results can provide reference for sound speed profile of inversion.