摘要
对于相位敏感的算法,声场时间相关长度是一个重要的参数。它能确定与相位有关的水声通讯算法的比特率和误码率,以及其他对相位敏感的信号处理算法如匹配场处理的信号增益。为了考察南海线性内波对匹配场时间相关长度的影响,本文分析了2001年亚洲海国际声学实验(ASIAEX2001)南中国海实验的水文数据,得到了符合该海域的内波频谱表示,并通过数值仿真研究了该海域存在线性内波时匹配场时间相关长度与声源频率f、收发距离R以及声速起伏δC的关系,总结了南海线性内波环境中匹配场时间相关长度的经验表示。仿真中所用的声源频率f为150～1200 Hz,收发距离R为20～32 km,声速起伏δC为1.37～5.0 m/s。结果表明,在该实验水文条件下,匹配场时间相关长度与δC^(-1.3)和f^(-1.1)成正比;在海底水平不变和水平变化时分别与R^(0.7)和R^(-0.5)成正比。
The signal coherence-time is an important parameter for phase-sensitive sonar applications.The signal coherence-time can determine the bit rate and error rate for phase-coherent acoustic communications algorithms and signal gain for the phase-sensitive signal processing algorithms such as matched-field processing（MFP）.In order to investigate the effects of linear internal waves on the coherence-time of MFP in the South China Sea,the internal wave spectrum is analyzed based on the oceanographic data,and the relationship between the signal coherence-time of MFP and the acoustic frequency f,the source-receiver range R,and the sound speed standard deviation（STD）δC is numerically investigated.In the simulation,the frequency is from 150 Hz to 1200 Hz,the source-receiver range is from 20 km to 32 km,and the STDδC is from 1.37 m/s to 5.0 m/s.It is found that the coherence-time can be fitted with an empirical equation satisfying a -1.3 power dependence ofδC,a -1.1 power dependence of frequency in this environment, and a -0.7 and -0.5 power dependence of range with range independent and range dependent water depth respectively.
出处
《声学学报》
EI
CSCD
北大核心
2011年第1期1-7,共7页
Acta Acustica
基金
中国科学院知识创新工程重大项目(KZCX1-YW-12-2)
国家自然科学基金项目(10974218
10734100)共同资助
