DISIA project

Simulation of Environmental Noise

in Urban Areas 

This page describes the computer programs included in the DISIA package. They have been developed, since 1995, by Angelo Farina, professor of Applied Acoustics at the University of Parma, Italy, under a contract with the Italian Ministry for the Environment. The DISIA package can be used freely at Universities, Schools, Research Centers, Public Health organizations, and in general at any public administration office, or at no-profit organizations taking care of environment and health, even if not-governative. The package cannot be sold to, or employed by, professional consultants or technicians who employ it for a profit. These subjects should use, instead, any of the available commercial programs, such as Soundplan, Mythra, Lima, etc.

Download =>

The DISIA package can be downloaded from http://pcfarina.eng.unipr.it/Public/DISIA/Download Subjects who qualify for its usage (see above) should contact the author for getting the installation password.  Email address: farina@unipr.it. Please do not bother to ask the password if you do not qualify for free usage....

Scheme of the programs and their interactions

Not all the programs shown above are part of the DISIA package. In particular Autocad™ and Surfer™ are commercial products, to be purchased separately.

The main modules of the DISIA package are:

• CITYMAP: this is the most important module, performing simulations and map with the "simplified" model (working in wide-band). It is also the interface program among the other modules (which are only required in case of "detailed" simulations) - most users only employ CITYMAP...

• DISIAPYR: computational engine performing "detailed" model simulations, employing the "Pyramid Tracing" method

• RAYCAD: simplified version of Ramsete CAD, for editing 3D geometries (required from the "detailed" model only) without need of using AutoCAD

• SOURCE MANAGER: editor of point source data, including directivity balloons and octave-band Sound Power Levels

• MATERIAL MANAGER: editor of acoustical properties of surfaces (octave-band absorption coefficient values)

Citymap
The workflow starts from AutoCAD™, or any other CAD capable of creating properly-formatted DXF files. Here is an example of the urban cartography as seen in AutoCAD:

The coloured entities are the acoustically-relevant objects, such as roads, railways, houses, noise barriers. All these are POLYLINE or 3DPOLY entities on proper layers.

It is also possible to draw point sources (ATTDEF or CIRCLE entities on the SOURCES layer) and receivers (CIRCLE entities on the RECEIVERS layer).

The relevant entities are exported to an ASCII DXF file, which is read by CITYMAP:

By right-clicking over any entity, it is possible to edit the acoustical information associated with it such as road or railway traffic data, etc:

Once all the information has been entered, it is possible to perform the computation of the sound pressure level, either at the previously-defined receiver points, or mapping over the whole area:

And this is an example of the colour mapping obtained:

The results are also saved in a standard GRD file, which can be employed by advancing mapping software, such as Surfer™, for creating more refined graphical rendering of the results (contour lines, etc.):

Finally, the contour line can be exported as a vectorial drawing, for example in DXF format, and hence it can be overcharted on the original cartography in AutoCAD™.

Bibliograhy
Several papers have been authored by Angelo Farina with reference to the DISIA project. All of them can be freely downloaded from here:

Copyright legal disclaimer. 

This web site is hosted on a computer located at the University of Parma (a public institution of the Italian Government, Ministry of Instruction, University and Research), under the direct control of Angelo Farina, who is a full-time employee of the University of Parma. The information contained here is just a reference for the underlying research work. This page IS NOT an advertisement for a commercial product. The software described here and the contents of this web site are subject to the normal law regarding copyright protection. No patent law is applicable.