  The 3D documentation of the tunnel surface during construction requires fast
and robust measurement systems. In the solution proposed in this paper, during
tunnel advance a single camera is taking pictures of the tunnel surface from
several positions. The recorded images are automatically processed to gain a 3D
tunnel surface model. Image acquisition is realized by the
tunneling/advance/driving personnel close to the tunnel face (= the front end
of the advance). Based on the following fully automatic analysis/evaluation, a
decision on the quality of the outbreak can be made within a few minutes. This
paper describes the image recording system and conditions as well as the
stereo-photogrammetry based workflow for the continuously merged dense 3D
reconstruction of the entire advance region. Geo-reference is realized by means
of signalized targets that are automatically detected in the images. We report
on the results of recent testing under real construction conditions, and
conclude with prospects for further development in terms of on-site
performance.
