We were pleasantly surprised by the excellent results, so we will soon be using the FARO Focus laser scanner for measurements that require high point-to-point accuracy.
Measurements:
Two adjacent planes were carefully scanned using the FARO ScanArm (measuring arm with LLP). A target surface was then generated from this data (=reference mesh).
The two planes were also scanned using the terrestrial laser scanner (TLS) at distances of 5 m, 9.5 m, and 17.5 m.
Alignment:
Best-fit alignment of each TLS point cloud to the reference mesh.
Analysis:
- The measurements from each TLS station at the three distances are considered individually.
- The TLS data is first processed using Faro Scene (no filtering; only the object of interest is extracted from the overall point cloud).
- Import of the FLS data into Polyworks (as a point cloud) and subsequent alignment of each point cloud to the reference mesh using best-fit.
- Calculation of a comparison between the TLS point cloud and the reference polygon mesh, and generation of a color comparison.
- Calculation of cross-sections through the generated color comparisons.
Conclusion:
An expected increase in deviations with increasing measurement distance could
not be detected (distances of 5 m, 9.5 m, and 17.5 m).
The level of accuracy can be determined within a range of ±0.5 mm.