两步法提高时延差估计精度的分析和实验验证

为提高短基线水声定位系统的定位精度,对利用两次估计提高时延差计算精度的方法进行了理论分析、仿真和实验验证,并给出了具体的实现步骤。该方法将时延差估计值分解成了时延差初测值和时延差修正值,前者直接利用相关函数包络求解,后者与相关函数相位差之间存在映射关系,通过频域的相位差估计获得。仿真和实验的结果显示,采用这一方法能够获得很高的时延差估计精度。两步法具有很强的实用性,可以有效的提高短基线水声定位系统定位精度。 

Analysis and experimental verification on improving time-delay difference estimation accuracy with two-step algorithm

In order to improve the positioning accuracy of short-base-line underwater acoustic positioning systems,a two-step algorithm for estimating time-delay difference value is analyzed theoretically and verified by simulation and experiments,and the implementing procedures are presented.In the algorithm,time-delay difference value is regards as combination of the value of initial time-delay difference testing and the value of time-delay difference modifying. The former is obtained from the peak value of envelopes of correlation function;the latter is calculated by phase difference estimation in frequency domain,because mapping exits between time-delay difference modifying value and phase difference value.The simulation and experimental results show that this method achieves high accuracy for time-delay difference estimation.The two-step algorithm is practical and can improve the positioning accuracy of shortbase-line underwater acoustic positioning systems effectively.