A compound random process for underwater ambient acoustic noise

A stationary compound process has been formulated and investigated as a model for underwater acoustic ambient noise pressure with long-term power fluctuations. The process is represented by
\sqrt{P(t)} G(t)
, where
P(t)
is a non-negative stationary random process, and
G(t)
is a zero-mean, unit-variance stationary Gaussian process independent of
P(t)
. The process
P(t)
, termed the power envelope, has a relaxation time much greater than that of
G(t)
and the latter determines the bandwidth of the compound process. With a suitable selection of parameters, the compound process conforms to the results of carefully analyzed experiments. The process has been employed to predict the performance of passive sonars operating in a fluctuating acoustical environment.