Development of Ladder-type Laser Scanning System for 3-D Modeling of Vertical and Narrow Areas by Space-time Analysis

In this paper, we propose a novel type of 3-D scanning system named ‘Ladder-type laser scanning system,’ designed for scanning vertical and narrow areas. Two line scanners are equipped on a moving platform on a ladder, and scan through the whole target while the platform moves downwards along the ladder. One scanner (main) is for scanning the target, and the other scanner (sub) is for localizing the platform by using spatio-temporal range image. We can accurately calculate the speed of the moving platform, with which a correct 3-D model can be constructed from the main scanner. The system was used for modeling Bayon Temple in Cambodia as a part of our digital archiving project of cultural assets, and the scanning results proved that the system gives a sufficiently accurate 3-D model.