When you have calculated a noise contour or noise levels at individual receivers, you will need to analyse them to extract conclusions about the noise impact of your project.
NoiseMap has a ‘Results Processor’ to help with this. Previous versions of NoiseMap had ‘Compare contour’ , ‘Noise Floor’ and ‘Offset to add’ functions, but the Results Processor lets you create your own processing functions.
In summary, you can:
- Download multiple results sets – eg multiple contour or receiver results
- Process the results sets to add and subtract both arithmetically and logarithmically,
- Add or subtract different source types, e.g. road and rail; industrial and background noise;
- Import results for receivers from an external file, for example to use as a background, a noise floor, or a noise criterion;
- Undertake comparisons between results, for example to show those exceeding a criterion;
- ‘Live’ receiver calculations can be included in the results processor.
The results processing can be as complex as you need, although ‘house-counting’ functions will come later.
Creating results expressions
You write expressions using a notation similar to that of Excel. For example, assuming R1, R2 and R3 are three sets of noise contours or receiver results, then:
R1 – R2 calculates the difference contour/results
LOGSUM(R1, R2, R3) calculates the cumulative effect of the results
MAX(R1,30) applies a noise floor of 30 dB to result R1
If(R1>67.5) and (R1>(R2+1)),1,0) could test for noise insulation
The results processor provides 25 mathematical operators, permitting a wide range of in-line processing.
Moreover, because receiver noise levels can be imported from an external file, these could be used as criteria to check for exceedances, for example on a construction site.
You can import results expressions from a script file, which allows complex processes to be prepared in advance and used as required.
Practical examples are shown here.