Level Crossing Probabilities for Multipath Acoustic Processes with Bimodal Spectra

Abstract

A general method of evaluating upcrossing probabilities for a class of random processes consisting of two narrow_band signals is presented. One of the two significant frequencies of the corresponding bimodal spectra is assumed to be dominant. The method approximates the maxima of these processes by the corresponding values of the envelope processes. It is also assumed that the discrete processes of the maxima are Markov. The results have several applications. Two prominent examples are detection problems of multipath partially saturated processes in underwater acoustics and the problem of the structural reliability of marine diesel engine shafting systems.