Calculation and Mapping
Noise levels at a receiver point can be calculated instead of measured. In addition, noise propagation from one measurement point to another can also be calculated.
In the following cases, calculation is preferable and may be the only method practicable:
- Where the levels to be measured are contaminated by high background noise, for example, when determining the noise from an industrial plant in the vicinity of a busy road
- Where future levels need to be predicted
- Where alternative development and noise reduction scenarios need to be compared
- Where noise contour maps need to be produced
- Where there is limited access to the measurement position
Calculation is normally performed in accordance with a recognised standard algorithm. This is usually determined nationally, or by industry sector, and often depends on the type of source.
Global, or strategic noise planning tries to prevent noise issues arising and to optimise the use of limited resources by mapping and managing the noise environment of a large area such as a city or airport.
Noise maps can be made by:
- Plotting measurements from long or short term noise surveys
- Plotting measurements from permanent monitoring stations