Driving changes

The German Fraunhofer Institute for Physical Measurement Techniques IPM has now developed the first laser scanner to deliver a 3D profile of the entire road surface and satisfy all the requirements for recording transverse evenness for condition surveys and construction acceptances. The 'pavement profile scanner' (PPS) is fitted to a vehicle belonging to the road German survey specialist Lehmann + Partner GmbH, which also developed the software for the system. In May 2012, the German Federal Highway Research Institute granted the PPS a limited-term permit to operate - the first time in Germany that a laser scanner has been registered to record road evenness. The laser scanner works on the principle of very high-speed time-offlight (TOF) measuring, based on the phase shift method. This involves modulating a laser beam and measuring the phase position of the backscattered light from this modulation signal. This method permits measurement of the laser beam's TOF with a res olution of just a few picoseconds.