脉冲对实现回波频偏测量的算法研究

Study on Pulse-to-Pulse Algorithmfor Measuring Acoustic Frequency Offset

声学多普勒流速剖面仪———ADCP技术是根据多普勒原理利用矢量合成法 ,遥测海流的垂直分布。频谱估计方法的研究是该技术的核心。文章详细剖析了脉冲对技术进行流速测量的方法 ,利用该算法可以很好的提取出淹没在白噪声下的频偏信息。由于信噪比SNR是影响该算法的一个重要参数 ,但不易直接获取 ,所以给出了评判参数C-SNR ,论证了C-SNR与SNR之间的必然关系。利用matlab6 5和VC ++6 . 0进行了仿真实验 ,并在DSP5 4 10中实现了该算法 ,海量实验数据证明 ,当C-SNR对应的值大于 0 .4 3时 ,频偏属于测频范围 [- 1/ 2τ ,1/ 2τ]内时 ,对应的数据是鲁棒的。

The ADCP(Acoustic Doppler Current Profiler) technique is used to far-measure the stereo velocity of ocean current with vector synthesis according to Doppler theory. And the frequency estimation algorithm is critical for it. Pulse-to-Pulse algorithm is discussed, and frequency offset estimate can be obtained easily with it. The parameter SNR is important to the algorithm, but it can't be achieved in general. The C_-SNR is raised and the certain relation between them is demonstrated. The results with matlab 6.5, VC++6.0 and DSP5410 indicate that frequency offset can be obtained robustly within [-1/2τ,1/2τ]when C_-SNR is no less than 0.43.