The influence of environment and source motion on broadband acoustic correlations: A normal mode approach Free

We deal with a source which emits a broadband signal S(t) while moving through a shallow (⩽300 m), range‐invariant environment at constant speed, depth, and bearing. The received signal is constructed from the result [K. E. Hawker, J. Acoust. Soc. Am. 63, 675–681 (1979)] for the S(t)∼e^iωt case. In terms of Fourier transforms, is the signal at r,z,t from a source on trajectory r₀(t) at depth z₀ and speech ν₀. θ(t) is the source‐receiver angle, $εn(ω) = ν0/νngp(ω)<1$⁠, and $ωn(ω,t) = ω − ν0kn (ω)[cos θ(t) − εn (ω)]$ is a Doppler‐shifted frequency. We model subkilohertz‐band signals in this way for fixed explosive sources (SUS) and for moving noise sources. The signal and its autocorrelation are compared with experimental data to determine the importance of environmental factors (gross SVP features, finer SVP details, bottom attentuation profile) and source motion (speed and cpa range), as well as source and receiver depths. [Work supported by DARPATTO and Naval Electronics Systems Command (Code 612).]