Issue link: https://geospatial.trimble.com/en/resources/i/1397758
as switching boxes, passenger benches and electrical housings that were not visible in the aerial images. A 600-m-long tunnel also required a team to install six LED headlights to compensate for the low-light conditions to capture features inside the tunnel walls. In total, the MX7 system collected 20,000 images. INTO THE ORTHO AVT personnel imported the processed aerial images and aircraft trajectory data and the GCPs into the MATCH- AT georeferencing module of Inpho to automatically triangulate the images. Using an image pyramid process, the software analyzed the 1300 images and automatically pinpointed 15,500 common features or tie points (TPs) across the images, averaging 200 TPs per image. The MATCH-AT module then used a bundle- The Trimble Geo 7X handheld can produce horizontal accuracy of 10 cm in real time. block adjustment process to automatically and precisely orient the imagery at an accuracy of around 1 cm in planimetry and altimetry. With the OrthoMaster module, the software automatically orthorectified the individual images with a ground resolution of 2 cm and OrthoVista stitched together each orthophoto to create a 2D orthomosaic for the whole AOI. With the OrthoVista Seam Edit tool, operators manually checked the seam lines to ensure they didn't cross objects like bridges which would be distorted in the mosaic. Any imperfections were fixed to create a seamless, color- balanced and geometrically correct orthomosaic of the 40-km-corridor. From there, the aerial images were exported into DAT/EM Summit Evolution software to create a 3D vector map of all railway-related features. The map was customized and finalized in AutoCAD. Top left: Designed for speeds up to 220 km/h, the Kundl- Baumkirchen dual railway crosses the Alps and is the northern connection to the Brenner Base Tunnel. Credit: OEBB Lower Left: The 40-km Kundl-Baumkirchen railway section was the first segment of the LIV that opened in November 2012. Above: The Trimble MX7 mobile imaging system was mounted on the roof of a small van and pulled by a special locomotive of the ÖBB. The mobile mapper complemented the aerial campaign. Cerdit: OEBB