The Copenhagen-Taastrup Railway Survey with RS4
Mobile Mapping Survey for the Copenhagen-Taastrup Railway Line
The Road-Scanner4 Mobile Mapping System, equipped with a Ladybug 5 camera, two Z+F Profiler 9012 laser scanners, and an IXBLUE Landins INS, was installed on a cantilever support of a service locomotive.
System and sensor were controlled and monitored during the survey missions from the locomotive cabin by means of a laptop connected to the Road-Scanner internal pc via Ethernet.
The survey included main and connecting lines for a total length of 18 kms.
In order to meet the requirements, 2 surveys were carried out: one by night, at the reduced speed of 18km/h, that produced very high density point clouds getting high accuracy (<2 cm) and one by day at the standard operating speed of 70/80 km/ h, to get high quality spherical images, acquired at a 3 m step.
The final results fully met the requirements:
• Absolute accuracy less than 2 cm
• High density point clouds, i.e. 2.5 cm distance between two scan-lines
• High quality spherical images
Forty Ground Control Points (GCP) were positioned along the lines. At each GCP, a very high accuracy of point clouds was registered, between 1 and 4.3 cm, with an average value of 1.9 cm. By calibrating the trajectories, the deviations were reduced to 1.5 cm at each points, with a perfect registration of the point clouds acquired in the various missions.
The previously surveyed GCPs were partially highlighted with suitable markers and partly collimated directly on the point cloud thanks to the high point cloud density and the software features.
The rough survey data (trajectories, images, and point clouds) were exported in standard format and used in various software applications for the production of the requested deliverables (planimetries, profiles, and sections).