相位编码信号声学多普勒测流中的波形参数优化方法

Optimization of phase coded waveform parameters in acoustic Doppler current measurement

针对相位编码声学多普勒测流中发射信号参数固定引起的适应性不强的问题,在基于信号模糊函数及其模的二阶导数的基础上,提出了两种根据测量需求和环境条件调整发射信号波形参数的优化方法,它们是分层精度约束下取得最佳速度估计精度的波形参数优化方法以及测速精度约束下实现最细分层厚度的波形参数优化方法,分别给出了参数优化的原理和具体的操作步骤。理论分析和实验数据分析结果均表明,相对于缺省参数信号,优化参数方法得到的信号具有明显的性能优势,且优化程度与理论预测基本相符。

In order to solve the problem of weak adaptability of the phase coded acoustic Doppler current measurement using the transmitting signal of fixed parameters,based on the signal ambiguity function and the second derivative of its modulus,two optimization methods are proposed to adjust the parameters of the transmitting signal waveform according to the measurement requirements and environmental conditions.One of the two waveform parameter optimization methods is to obtain the best velocity estimation accuracy under the constraint of layered accuracy and the another one is to achieve the most subdivided layer thickness under the constraint of velocity measurement accuracy.The principle and specific operation steps of waveform parameter optimization are given respectively in this paper.The results of theoretical analysis and experimental data analysis show that compared with the signal of default parameters,the signal obtained by the optimized parameter method has obvious performance advantages,and the optimization degree is basically consistent with the theoretical prediction.