Pass-by Noise Analysis

Array-based pass-by noise analysis is more complex to implement than standard measurements using isolated sound level meters. However, it provides invaluable support in optimizing noise reduction, with the contribution of the various noise sources to the overall noise level.

MicrodB’s experience in this type of application is indispensable for obtaining the required data quality following appropriate measurements and processing. The difficulty of pass-by noise measurements lies in their implementation and processing in the field. They can only be carried out in real traffic conditions, outdoors, coupled with vehicle trajectory information. Data analysis may require the signals to be de-dopplerized, which means acquiring a precise vehicle trajectory perfectly synchronized with the acoustic measurements. MicrodB can help you with such projects, either by supplying a device or by implementing it. Our teams will do their utmost to deliver the best results.

Pass-by noise array techniques are based on lateral measurements on runways for ground transportation, on the ground for aeronautics, and in the water using hydrophone arrays for marine and underwater equipment. MicrodB has an array optimization tool to define the array best suited to the measurement environment and the type of noise sources to be separated.

In the processing phase, various algorithms can be implemented depending on the speed of the craft: beamforming including de-dopplerization for fast speeds, or processing over short time windows for slow speeds, followed by deconvolution to best separate and quantify noise sources.

MicrodB has in-house software tools adapted to each application, and can build a measurement array if required. We can offer these tools for sale, or use them as part of a service package.