Environment objects contain settings that affect sound propagation, such as air and ground properties.

Environment objects are also the containers for Barrier objects.

Input Parameters

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Name Data type Unit Comment
Library item Lib. item - The library item for the environment.
Ground height Number m The relative height between the ground and the top of the rail. Value must be negative, i.e. the ground is below the top of the rail.
Absorption model Choice - The absorption model used in the calculations. Available options are: No ground, Rigid ground, Miki, Delany-Bazley, or Hamet-Bérengier.
Thickness Number m The thickness of the ground layer.
Flow resistivity Number Pa.s/m2 The flow resistivity of the ground layer.
Porosity Number - The porosity of the ground layer.
Tortuosity Number - The tortuosity of the ground layer.
Air temperature Number °C The temperature of the air.
Density Number kg/m3 The density of the air.
Speed of sound Number m/s The speed of sound in air.
Custom graphics file File - Custom background graphics can be added to the model; the file to use is specified here (with ’.xml’ file extension ).