Temporal variations of the statistical properties of an underwater acoustic channel measured at a shallow water in 2009

Complicated and time-varying environment of the ocean makes it difficult to describe properties of underwater acoustic channels. Therefore, many researchers have tried to characterize underwater channels using a statistical approach. Although theoretical analysis shows that the probability density function (PDF) of the propagation channel may have Rayleigh or Rician distribution, we still do not know how the statistical properties change for different time and conditions. Recently, Kim et al. and Borowski confirmed again experimentally that PDFs can be fitted to Rayleigh or Rician distributions. However, the results are based on limited data of very short time. In this paper the change of statistical properties are examined using long time observation. Not only magnitude and phase but also phase change rate is analyzed. The results show that the statistical parameters are changing continuously with a certain amount.