Apparatus for measuring rail rolling surface ruggedness during track exploitation

The measuring device uses a distance measuring head (12) with an electromagnetic radiation source and a detector for the radiation (16) reflected from the track rail surface (14), evaluated for providing the characteristic surface roughness of the track rail. An acceleration sensor (13) is attached to the measuring head for measuring the acceleration component perpendicular to the rail surface, which is integrated for providing a position variation signal combined with the rail distance signal before Fourier transformation.