AcousticsToolbox

This package provides a Julia wrapper to the OALIB acoustic propagation modeling toolbox, making it available for use with UnderwaterAcoustics.jl.

Currently, only two of the OALIB models are supported:

• Bellhop 2D Gaussian beam tracer (almost complete support)
• Kraken 2D normal mode model (partial support)

---

Installation

julia> # press ]
pkg> add UnderwaterAcoustics
pkg> add AcousticsToolbox
pkg> # press BACKSPACE
julia> using UnderwaterAcoustics
julia> using AcousticsToolbox
julia> models()
3-element Vector{Any}:
 PekerisRayModel
 Bellhop
 Kraken

Usage

The propagation modeling API is detailed in the UnderwaterAcoustics documentation. We assume that the reader is familiar with it. This documentation only provides guidance on specific use of Bellhop and Kraken propagation models.

Bellhop

Additional options available with Bellhop:

• nbeams -- number of beams used for ray tracing (default: auto)
• minangle -- minimum beam angle in radians (default: -80°)
• maxangle -- maximum beam angle in radians (default: 80°)
• gaussian -- geometric rays if false, Gaussian beams if true (default: false)
• debug -- if true, intermediate Bellhop files are made available for user inspection (default: false)

Example:

using UnderwaterAcoustics
using AcousticsToolbox
using Plots

env = UnderwaterEnvironment(
  seasurface = Vacuum,
  seabed = SandyClay,
  ssp = SampledSSP(0.0:20.0:40.0, [1540.0, 1510.0, 1520.0], :smooth),
  bathymetry = SampledDepth(0.0:50.0:100.0, [40.0, 35.0, 38.0], :linear)
)
pm = Bellhop(env; gaussian=true)
tx = AcousticSource(0.0, -5.0, 1000.0)
rx = AcousticReceiverGrid2D(1.0, 0.1, 1000, -40.0, 0.2, 200)
x = transmissionloss(pm, tx, rx)
plot(env; receivers=rx, transmissionloss=x)

For more information on how to use the propagation models, see Propagation modeling toolkit.

Kraken

Additional options available with Kraken:

• nmodes -- maximum number of modes (default: 9999)
• nmedia -- number of medium (default: 1)
• nmesh -- number of mesh point to use initially (0=auto, default: 0)
• clow -- lower phase speed limit in m/s (0=auto, default: 0)
• chigh -- higher phase speed limit in m/s (larger values => more modes, default: 1600)
• debug -- if true, intermediate Kraken files are made available for user inspection (default: false)

Example:

using UnderwaterAcoustics
using AcousticsToolbox
using Plots

env = UnderwaterEnvironment(
  seasurface = Vacuum,
  seabed = SandyClay,
  ssp = SampledSSP(0.0:15.0:30.0, [1447.0, 1455.0, 1460.0], :smooth),
  bathymetry =  ConstantDepth(30.0)
)
pm = Kraken(env)
tx = AcousticSource(0.0, -5.0, 1000.0)
rx = AcousticReceiverGrid2D(1.0, 0.1, 5000, -30.0, 0.2, 150)
x = transmissionloss(pm, tx, rx)

plot(env; receivers=rx, transmissionloss=x, clims = (-60.0,0.0))

For more information on how to use the propagation models, see Propagation modeling toolkit.

Contributing

Contributions in the form of bug reports, feature requests, ideas/suggestions, bug fixes, code enhancements, and documentation updates are most welcome. Please read contribution guidelines if you wish to start contributing.

The scopes active in this repository are:

• bellhop: Bellhop
• kraken: Kraken