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Description
The primary objective of the RailNoise project is to enable reliable railway noise calculations using the calculation methods Nord2000 and CNOSSOS-EU. This requires gathering source emission data for both methods representing all operational train classes currently in regular use, and addressing limitations within standard CNOSSOS-EU, which lacks the 1/3-octave band resolution and maximum sound level (Lmax) results required by Norwegian noise regulations. The noise measurements are based on ISO 3095/NS 8177 but adapted for measuring in-service trains on operational railway lines. Computational back-propagation techniques are applied to account for locally varying ground impedance and to derive absolute sound power levels. Based on measured data, rails and wheels are classified by surface quality, for use in noise calculations.This paper presents the measurement methodology, the back-propagation process, and the process of converting the measured emission data into source data.