首页   按字顺浏览 期刊浏览 卷期浏览 The effect of saturated transmission scintillation on ocean acoustic intensity measurem...
The effect of saturated transmission scintillation on ocean acoustic intensity measurements

 

作者: Nicholas C. Makris,  

 

期刊: The Journal of the Acoustical Society of America  (AIP Available online 1996)
卷期: Volume 100, issue 2  

页码: 769-783

 

ISSN:0001-4966

 

年代: 1996

 

DOI:10.1121/1.416239

 

出版商: Acoustical Society of America

 

数据来源: AIP

 

摘要:

Coherence theory is used to analyze the statistical properties of ocean‐acoustic intensity fluctuations measured after saturated multipath propagation. Previous analyses in this area have been implicitly limited to certain special cases for which the time‐bandwidth product of the field received from a given source is unity. In this paper, the statistical description is extended and generalized to be a function of measurement time and temporal coherence. As a result, the well known 5.6‐dB transmission loss (TL) standard deviation of Dyer is found to be a special case of a more general TL standard deviation that approximates 4.34 sqrt(1/μ) dB when the time‐bandwidth product μ is large. Therefore, the TL standard deviation approaches zero for increasing μ, as it must in the deterministic limit of an arbitrarily large sample size. A similar generalization is obtained for the TL mean, from which it is found that the sonar equation must be corrected for a μ‐dependent bias that vanishes in the deterministic limit of large μ. Additionally, asymptotic analysis shows that intensity statistics in the saturated region converge to a log‐normal distribution, where μ≳4 is typically sufficient for the log‐normal approximation to be made.

 

点击下载:  PDF (272KB)



返 回