An Image-Based Inspection System for Canal Tunnel Heritage

Nowadays, 33 canal tunnels, mainly bored during the 19th and 20th centuries, are still used in France for commercial navigation and boating. The preservation of this heritage is not only essential for cultural and historical reasons but also for economical necessities and security issues. A French partnership proposes to develop a prototype dedicated to the image-based inspection of canal tunnels. In this paper, we address the problems of image quality and location accuracy, which is particularly challenging since no conventional global referencing system is available in tunnels. We introduce the dynamic imaging system that has been tested during recording campaigns in Niderviller tunnel. Several solutions to locate the inspection barge have been also investigated. The experimental evaluation on the accuracy of the referencing methods is presented and analyzed.