Retracing positions of terrestrial laser scanners to reinstate legacy point clouds

Laser scanners provide a mostly geometric representation, but further details can be collected by analysing the recording setup. While the recording configuration is needed in post-processing, it is generally not passed on to the engineers as most scans are created by surveyors and handled by subcontractors. This disconnection between the consumer and the creator can be observed by the fact, that most laser scanned point clouds include intensity information. In day to day use, the intensity information serves as a substitute for colour as it provides contrasts between different objects in the recording. However, from the technical perspective the intensity is the result of the recording device interacting with the surface. This interaction should not be used for automation as different recording setups may result in different interactions and outcomes. Facing this problem, we propose a mechanism to enrich terrestrial laser scans by recreating original scan parameters and further converting the intensity to reflectivity - a sole property of the recorded surface.