Acoustic sensing of temperature changes in a strongly range-dependent ocean
K A Naugolnykh; E C Shang; Yun-Yu Wang
Журнал:
Inverse Problems
Дата:
2000-12-01
Аннотация:
The inverse problem of inferring information about the
intervening ocean can be solved by a comparison of the computed
arrival times and measured patterns of arrivals. This approach
is very effective if in the process of sound signal propagation
the modal energy exchange is negligible, the mode propagation
can be considered as adiabatic and each mode has a clear
amplitude and phase. In the range-dependent ocean, drastic
`repopulation' of the modes takes place due to intense energy
exchange. The energy distribution between modes changes, and the
order of modal arrivals varies. For the strong-mode-coupling case a
fixed mode travel time does not have a monotonic relationship
with the temperature variation. To obtain monotonic dependence of
the sound signal parameters upon the environmental
characteristics, specific approaches to the forward problem
solution have to be used; two of them - the collective arrival
time and the cumulative sum - are considered in
this paper. They consists of defining trends in the
signal arrival pattern caused by the temperature changes, and
computing average parameters of the arriving signal ensemble.
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