改进粒子滤波在海底地声参数反演中的应用

Application of improved particle filtering in geoacoustic inversion

海底地声参数作为海洋声信道的重要组成部分,很大程度上决定了海洋声传播特性。地声参数可以通过反演算法获得,与距离相关的地声反演问题近年来是研究的热点。粒子滤波是一种高效的序贯寻优算法,可以在海底声学特性随距离缓慢变化情形下,有效解决地声参数的估计问题。但当海底声学特性随距离变化剧烈,如沉积层分层情况发生改变时,传统的粒子滤波则可能失效。为解决此问题,有文献使用了带桥接重采样的粒子滤波反演地声参数。文章在此基础上进一步改进了粒子的采样方式,并将此方法应用到基于海底反射系数的反演中。通过仿真数据处理结果证明,文中提出的改进粒子滤波在地声参数随距离变化剧烈的情况下仍具有较好性能,可以准确地估计海底特性随距离的变化规律和海底沉积层的声学参数。

As an important part of ocean acoustic channel,the geoacoustic parameters of seabed largely determine the characteristics of ocean acoustic transmission.Geoacoustic parameters can be obtained by inversion algorithm,and the range-dependent geoacoustic inversion is a hot research issue in recent years.Particle filtering is an efficient sequential optimization algorithm,and the traditional particle filtering algorithm can be used to estimate the geoacoustic parameters when the seabed characteristics change slowly with range.However,when the seabed characteristics change dramatically with range,such as in the case of stratification change,the traditional particle filtering algorithm may fail.In order to solve this problem,some literatures use the particle filtering with bridging re-sampling for geoacoustic parameters inversion.On this basis,the particle sampling method is further improved in this paper,and the improved method is applied to the inversion of seafloor reflection coefficient.The processing results of the simulation data prove that the improved particle filtering algorithm proposed in this paper still has good performance under the condition that the geoacoustic parameters of seabed change dramatically with range,and can accurately estimate the variation law of seabed characteristics with distance and the geoacoustic parameters of sediment layers.