When driving by, even a long freight train is put together to form a single picture and color-coded with the acoustic data. This pass-by picture shows at a glance in which areas of the entire train the loud places can be found.
The PassBy 2D software module creates a panoramic image with the feature point method. That means: Looking for feature points in individual frames and stitching them together. From the moving distances of the feature points and the frame rate of the camera velocity information of the measured object is also created.
The calculation of an acoustic map works like a TDBF (time domain beamforming) algorithm with variable runtimes. Every point of the measured object is followed a given amount of time while it is in the proximity of the microphone array.
- Pass-by analysis
- Time and frequency domain
- Frequency bands (narrow, 1/3-, 1/1-octave)