INTERNAL INTERFACE CONDITIONS FOR FINITE-DIFFERENCE PE APPLICATIONS TO LAYERED ACOUSTIC MEDIA

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Authors
  1. Brooke, G.H.
  2. Wort, P.M.
Corporate Authors
Defence Research Establishment Pacific, Victoria BC (CAN)
Abstract
The traditional one-way parabolic equation (PE) formulation for range-dependent layered acoustic media is modified to include effects associated with interfaces internal to the computational grid. Both first- and second-order approximations are derived which effectively translate the effects of internal boundary conditions onto nearby grid points. The approximations are based on a procedure presented by Collins (J. Acoust. Soc. Am., 86 (1989), 1459-1464) in which auxiliary field variables are defined above and below the interface. Consideration of second-order conditions also allows sloping internal interfaces to be accommodated. Numerical results obtained for standard test cases are used to demonstrate the application of the analysis. In shallow water, particularly at ranges greater than 20 km, there is an indication that precise definition of the interface depth is required in order to minimize errors that could negatively affect matched field processing applications. Alternatively, imprecision in interface location to within one computational grid width does not significantly affect the field prediction in oceans with water depths greater than 500 m or so.
Keywords
GHBPE ALGORITHM
Report Number
DREP-TM-94-145 — Technical Memorandum
Date of publication
01 Dec 1994
Number of Pages
38
DSTKIM No
95-02996
CANDIS No
149066
Format(s):
Document Image stored on Optical Disk;Hardcopy

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