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For the purpose of analyzing the effect of uncertain environmental parameters on acoustic field in shallow water, the functional relations between acoustic field and uncertain environmental parameters are constructed by nonintrusive polynomial chaos expansion ( NPCE ) method, and an analytical method for the local sensitivity of acoustic field to single uncertain parameter is proposed. A method for analyzing the qualitative sensitivity is presented according to the variation of probability distribution of acoustic field before and after the variation of certain uncertain parameter when more parameters are uncertain, and then the global sensitivity is quantitatively calculated by introducing the Sobol index method. The results show that the proposed methods can be used to obtain the sensitivity of acoustic field in shallow water to certain parameters quickly, which can be use to optimize the model of uncertain environmental parameters. [ABSTRACT FROM AUTHOR]

A method is proposed for measuring the detection range of passive sonar in uncertain ocean environments. The relationship between the detection range of passive sonar and the uncertain parameters of ocean environment are inferred when there are single and multiple uncertain parameters in the ocean environment, the probability distribution functions of detection range of passive sonar are obtained, and then the detection ranges of passive sonar in ocean environment are determined based on the maximum likelihood criterion. For the cases of the single and multiple uncertain parameters of ocean environment, the detection ranges of passive sonar are calculated. The proposed method makes full use of information of PDF of the uncertain environmental parameters, and needs not to specify the type of PDF of ocean environmental parameters and set any threshold for determining the detection range as well. [ABSTRACT FROM AUTHOR]