多波束测量声速剖面EOF表示阶次选取研究

经验正交函数(EOF)是描述声速剖面的有效基函数,通常只需要前几阶EOF即可较为精确地表示声速剖面。但使用EOF重构的声速剖面进行多波束测量声速改正时,选取的阶次未必满足多波束测深精度要求。针对此问题,首先介绍了EOF表示声速剖面的原理及流程,然后以北海某区域实测声速剖面数据为例,分析了不同阶次EOF拟合声速剖面误差以及不同阶次EOF拟合声速剖面对多波束测深的影响,最后结合NOAA对多波束测量声速剖面误差造成的水深限差要求确定EOF阶次,实现了在满足多波束测深精度的同时,合理确定EOF阶次的目的。

Order Selection of EOF Expression of Sound Velocity Profile in Multibeam Surveys

The empirical orthogonal function (EOF),an effective basis function,is used to describe the sound velocity profile which can be usually expressed by fore some orders of EOF.However,the order selection of EOF may dissatisfy the accuracy of multibeam bathymetry when the reconstruction sound velocity profile with EOF is used for sound velocity correction.In order to solve the problem,firstly,the principle and procedure of sound velocity profile expressed with EOF is introduced,secondly,the fitting error of sound velocity profile and the influence of the multibeam bathymetry with different orders are analyzed,and finally,the orders of EOF are obtained combining the NOAA tolerance for sound velocity profile error in the multibeam survey.The research achieves the goals of satisfying the accuracy of multibeam bathymetry as well as confirming the EOF orders reasonably.