Accession Number ADA571772
Title Travel-Time and Amplitude Sensitivity Kernels.
Publication Date Sep 2011
Media Count 13p
Personal Author B. Cornuelle E. Skarsoulis M. Dzieciuch
Abstract LONG-TERM GOALS: Our long-term goal is to study the sensitivity behavior of travel-time and arrival-amplitude observables due to sound-speed perturbations in low-frequency, long-range acoustic propagation in the ocean. OBJECTIVES: The leading objective of this project is to rigorously study the asymptotic behavior of wave-theoretic travel-time sensitivity kernels with increasing range, as a means to explain their observed convergence towards the corresponding ray-theoretic sensitivity kernels even at low frequencies. Further objectives include the derivation and study of 2D and 3D first-order amplitude sensitivity kernels, as well as vertical sensitivity kernels for arrival amplitudes, first-and second-order. A last objective is the study of sensitivity behavior of late arrivals depending on propagation frequency and range. APPROACH: Previous work has revealed a numerical convergence of wave-theoretic travel-time vertical sensitivity kernels (VTSKs) towards the corresponding ray-theoretic sensitivity kernels with increasing range even at low frequencies. To study this behavior, the asymptotic form of finite-frequency kernels with increasing range is rigorously derived here using a stationary-phase approach. The wave-theoretic VTSK involves an integral over frequency with a rapidly oscillating kernel, the oscillation rate increasing with propagation range. The stationary-phase approach is used to evaluate the asymptotic form of this integral and finally of the VTSK for long ranges.
Keywords Acoustic velocity
Amplitude
Asymptotic series
Behavior
Convergence
Frequency
Low frequency
Numerical analysis
Ocean environments
Oscillation
Perturbations
Propagation
Sensitivity
Sound transmission
Travel time
Vertical orientation


 
Source Agency Non Paid ADAS
NTIS Subject Category 47C - Physical & Chemical Oceanography
46A - Acoustics
Corporate Author Scripps Institution of Oceanography, La Jolla, CA.
Document Type Technical report
Title Note Annual rept.
NTIS Issue Number 1316
Contract Number N00014-11-1-0186

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