NMPB-Routes 2008
Calculation accord. to ...
CadnaA displays the edition on which the contemporary implementation is based upon.
Calc exactly one Reflection Order
By default, this option is deactivated. In this case, the maximum order of reflection is specified via the „Reflection“ tab (see Reflection Tab).
With this option being activated just 1st order of reflection will be considered. In this case, higher reflections should be accounted for by the multiple reflection correction according to RLS-90 RLS-1990 (see below).
Use Multiple Reflection Correction
When this option is activated the multiple reflection correction is calculated according to RLS-90 (see RLS-90), based on additional input data in the edit dialog of each road object. By default, this option is deactivated.
Note
The application of both options, „Calc exactly one Reflection Order“ and „Use Multiple Reflection Correction“, may heavily reduce the calculation time as NMPB-method usually requires a higher order of reflection to be selected to obtain realistic levels.
In this case the dialog is extended at the bottom right by an input scheme to enter the required data (for details see RLS-90, Correction for Multiple Reflections).
Calculate outer Lanes separately
By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.05 m). When this option is deactivated just the road’s center line represents the emission line.
Year of Calculation
Enter here the actual year of calculation used to correct for the aging of the road surface (for details see NMPB-Routes 2008).
Calc Atalus
In NMPB 2008, the attenuation due to the embankment Atalus is part of the attenuation due to the boundary of the propagation medium in downward refraction conditions Afront,F („talus“ is French for „embankment“).
This option is activated by default. In this case, Atalus is calculated and included in Afront,F. When deactivated, Atalus is zero.
Note
This option is also relevant when applying the „reference DLL“ (see below).
Use Ch in Calculation of Abar
By the factor Ch the attenuation by „pure diffraction“ is modified for barriers (not for terrain contours). Activating this option may lead to a lower barrier attenuation (for details see NFS31-133-2011).
Use reference DLL
This option is deactivated by default. In this case, CadnaA code is used for the calculation, implemented based on the printed documentation of NMPB 2008.
By activating this option the later released, but officially provided reference DLL (developed by the French consortium) is used for the calculation.
This option requires to copy the reference DLL (PropagationNMPB.dll) into the respective CadnaA installation directory. The DLL is not part of the CadnaA installation procedure and is, therefore, distributed separately.