Efficient digitization of the Zentrum am Berg research tunnel – From laser scan to triangulated surface model within one day.

Unthinkable just a few years ago, the precise laser‐scanning survey of a kilometer‐long tunnel in one day by one operator has become possible. This article describes how 261 scans were taken with a RIEGL VZ‐400i laser scanner to digitize the Zentrum am Berg (ZaB) research tunnel with millimeter resolution. The data has been automatically registered during the acquisition process within the instrument. After applying multistation adjustment, a block adjustment postprocess step, the high accuracy of the point cloud with respect to a network of 35 retroreflective bireflex targets has been approved. For further applications such as analysis, simulation, or visualization, a homogeneous 3D‐meshed surface model has been created automatically from the point cloud representing an as‐built 3D documentation of the tunnel. [ABSTRACT FROM AUTHOR]