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This paper deals with the practical use
of simple computer tools in assessing and mapping external noise. The process
is divided into five main steps:
1. Evaluation of the external noise
situation (e.g. road traffic noise, noise from railbound traffic, noise from
wind turbines, shooting range noise).
2. Conditioning of input data using
low-cost computer tools. The emphasis will be on topography and buildings.
3. Building the corresponding noise
model in a computer tool.
4. Output data conditioning using low-cost
computer tools.
5. Noise maps and other graphical
presentations using a low-cost mapping tool.
The main output data from the noise
model is regular or non-regular grids of computed dB-values. For noise mapping
these grids must be interpolated in some way.
Different ways of such interpolations
are discussed in some detail, showing typical variations and pitfalls.
The process is similar to the
corresponding process using off-the shelf computer tools but the steps have to
be done separately using stand-alone tools, yielding
a less automated but in some instances a more flexible and
cost-effecive way to do the noise assessment tasks.