Laser scanning ensures exhaustive data capture within a tunnel ; the subsequent processing provides both a survey of the existing situation and a check on the structure gauge (checking of clearances).
Depending on the accuracy required, the density of information and the time available for survey operations, several methods are possible. The use of a fixed or mobile scanner will depend on the technical specification.
If necessary we can also run precise traverses to control the scanner stations; the structure as a whole is thus represented by a complete point cloud from which all necessary information can be extracted.
The tunnel survey results can then be expressed in terms of the extraction of profiles, the highlighting of clash zones between the structure gauge and the existing situation, a check on clearances or a measurement of volume.