摘要
针对海水媒质分布不均匀的特性,本文提出了一种在非均匀媒质中联合到达时间(TOA)和到达角度(DOA)浅海多径环境下的定位算法.该算法不仅能够克服声速变化引起的路径弯曲问题,还可以减少海水流动对节点拓扑结构产生的影响.首先分别以海面和海底为反射面建立锚节点的虚拟节点(VN),把多径环境下的非视距(NLOS)问题转化为视距(LOS)问题,然后根据声速剖面(SSP)利用费马原理获得声波曲线路径的表达式.又由于海面、海底形状的不规则性,信号在反射点发生散射现象,因此将反射点当作分布式信源,利用散射信号中心波达方向作为DOA,平均波达时间作为TOA.最后利用到达时间和到达角度估计目标的位置参数.仿真结果表明,本方法在定位精度和鲁棒性等方面优于传统的直线传输模型.
To overcome the problem caused by the inhomogeneous water medium,a joint time-of-arrival(TOA) and direction-of-arrival (DOA) localization algorithm considering theinhomogeneous water medium in shallow ocean multipath environment is proposed. This algorithm can not only avoid the slanted path induced by the various soundspeeds,but also reduce the influence of dynamic underwater network topology. Firstly,the virtual node (VN) of the anchor node was set up based on the surface and the bottom of the sea to convert the non-line-of-sight (NLOS) prob-lem into a line-of-sight (LOS) problem. Then,according to the known sound speed profile (SSP),the numerical path of signal was derived by using Fermat’s principle. Furthermore,due to the irregularity of sea surface and seabed,the signal was scattered at the reflection point. So the reflection point was regarded as a distributed source,and the central angle and the average arrival time was regarded as DOA and TOA,respectively. Finally,the location parameter of target was estimated by TOA and DOA. The simulation results indicate that the proposed method is supe-rior to conventional straight line propagation model in location accuracy and robustness.
出处
《天津大学学报(自然科学与工程技术版)》
EI
CSCD
北大核心
2018年第2期129-134,共6页
Journal of Tianjin University:Science and Technology
基金
国家自然科学基金资助项目(61501322)~~
关键词
非均匀媒质
多径
声音速度剖面
费马原理
虚拟节点
inhomogeneous medium
multipath
sound speed profile
Fermat’s principle
virtual node