【摘要】 声学多普勒流速剖面仪(ADCP)[1]技术是目前观测海流剖面的最有效方法,其基本原理是测定声波入射到海水中微颗粒后向散射造成的多普勒频移。文章详细剖析了复自相关技术进行流速测量的方法,给出了评判参数C-SNR,论证了C-SNR与信噪比(SNR)之间的必然关系,作为取舍数据的评判标准。海量实验数据证明,当C-SNR对应的值大于0.43时,频偏属于测频范围-21τ,21τ内时,对应的数据是鲁棒的。详细地的介绍在定点DSP-TMS320VC5410中实现该算法的过程,并和传统最小二乘算法(LMS)[2]在DSP中的运行时间进行了比较,结果表明复自相关算法在提高计算精度的过程中能够保持更高的运算速度,随样本比例增加,耗时比约为2.1∶1.更多还原

【Abstract】 The acoustic Doppler current profiler(ADCP) is regarded as the best means in the observation of the stereo velocity of ocean current.Its basic theory lies in the estimation of the Doppler frequency offset.A complex correlation algorithm was analysed in detail,and frequency offset estimation was easily obtained with it.The parameter,C_-SNR,was obtained and the necessary relation between C_-SNR and SNR was demonstrated.The enormous data indicate that the frequency offset is robustly obtained within-12τ,12τ when C_-SNR is no less than 0.43.Realization of the algorithm in fixed-point DSP-TMS320C5410 was explained in some detail.Also,the running time of complex correlation algorithm and LMS in DSP was determined.The results indicate that the ratio of consumed time is 2.1∶1 when compared with the sample data growing as direct proportion.更多还原