Laser scanning for highly accurate data
In order to capture a facade three-dimensionally and in detail, laser scanning technology has been applied. By means of the laser scanner FARO Focus3D, five scans of a facade could be created within one hour. The gained laser scanner data shall serve as a basis for precise, scaled drawings in the CAD system GEOgraf and allow detailed planning.
Scanning of the facade
In order to capture all distinctive edges and hidden angles, five sites have been determined for the scanner. By means of the various positions and a scan radius of 15m (590.5 in), the façade has been recorded completely and of high quality (resolution of 0,002m (0.08 in)). The results of the scanning, the point clouds, provide millions of points of the facade. By means of reference spheres used for laser scanning, the single point clouds have been referenced and merged to a comprehensive point cloud.
Façade to be scanned. The distinctive edges are marked by means of arrows.
Scan radius of the single scanner positions
Position of the reference spheres
In order to scan a facade optimally and to determine the appropriate laser scanne rpositions, read the following article: How do I position a laser scanner to scan a facade?
Analysis and interpretation of the scan results
The scan results have been analyzed and interpreted within only 45 minutes. In our laser scanning software PointCab, a layout and a sectional view of the facade have been generated in a short time. The calculation was realized in black and white as well as in color. The results in black and white show the edges very clearly and, thus, they are suitable for construction purposes. However, colored images allow an easy determination of the single materials. Afterwards, the results can be used in different CAD systems.
Section of the façade in color – PointCab layout
Section of the façade in black and white – PointCab layout
Sectional view in color in PointCab
Layout in black and white in PointCab
Laser scanning – The appropriate method for facade measurement
Facade measurements are used for structural changes of the facade, for instance for assembling balconies or for the restoration of buildings and facades. Detailed facade measurements for the monuments administration, for instance, can easily and quickly be registered by means of this method.
Until now, facades often have been analyzed by means of a tachymetrical method or photogrammetry. By use of the total station, only single points could be determined; in photogrammetry, differences in the facade's depth could only be determined sophisticatedly. Laser scanning in conjunction with PointCab not only provides a detailed extensive image as well-known from photogrammetry. Even precise geometric data (xyz-coordinates) of all façade points is exactly captured.
