Precise Long Tunnel Survey using the Riegl VMX-250 Mobile Laser Scanning System

Our company has been using the RIEGL VMX-250 since July 2010 in diverse scenarios, especially where data acquisition productivity is pertinent. In this presentation, we will be describing a long tunnel survey project. Spain has the longest high speed trail network in Europe. Recently, two parallel 25 km long tunnels were built and an accurate 3D survey was demanded by the Spanish authorities. Artescan accomplished this survey using the RIEGL VMX-250. The integrated INS-GNSS is specified for 1 minute GPS outages; however, in this case, each survey project was realized with approximately 1 hour of total GPS outage in the mobile receiver. An absolute accuracy of 2 cm was achieved by using a combination of well acquired exterior GPS positioning, INS and odometer measures inside the tunnel and use of control points. For trajectory adjustment, RiProcess powerful tools were successfully used.