Sound‐level fluctuations in a multipath environment

Abstract

For each array sensor j in a medium of M multipaths, the composite sound‐level mean‐squared sound‐level fluctuation (χ′j2)¯ can be found by a complicated development to be constructed from the summation of the individual multipath mean‐squared sound‐level fluctuations (χ′mj)2)¯ and of the multipath mean‐square phase fluctuation (θmj2)¯ where χ = In A, A is the signal amplitude and m = 1, 2, …, M. Applying the appropriate fluctuation relations from Tatarski [Wave Propagation in a Turbulent Medium (McGraw‐Hill, New York 1961)] and Schvachoko [“Sound fluctuations and random inhomogeneities in the ocean,” Sov. Phys‐Acoust. 13, 93 (1967)], the result is (χ′j)2¯ ≃ 4Mμ2Lnk02R, where μ2 is the mean‐square sound‐speed fluctuations, Ln is integral scale, K0 is the wavenumber and R is the range. [Work supported by NAVELEX Code 320.]