Missing results are shown as -99. This indicates that no noise level has been calculated for that case. This can happen in many ways, for example:
- A tile was not calculated
- The receiver point was outside the angle of view or beyond the cut-off distance
- The receiver point was inside a building
- There were no noise sources of the type applicable to the chosen calculation
Your case was the last of these - you wanted to calculate the Leq of
rail noise sources, but chose the CRTN calculation method.
Each calculation method is applicable to its own type of source:
- CRTN for Roads
- CRN & TNPM for Rail
- BS5228 for Open sites
Please beware that choosing Leq calculations will NOT calculate noise for all types of source.
Please also beware that the choosing a category combination like Road + Rail does not (and cannot) add together noise from road and rail sources.
Adding noise from different types of noise source
To do this, you must
- firstly calculate the road sources using CRTN and the rail sources using CRN or TNPM; and then
- use the Results Processor to add together the noise from the two types of noise source
