Measurement of Landslide Displacement by object extration with ground based Portable Lased Scanner
Kouji UJIKE and Msataka TAKAGI
Kochi University of Technology
Tosayamada-cho, Kochi, 782-8502, Japan
Email: 075013b@gs.kochi-tech.ac.jp
ABSTRACT
Landslide is a phenomenon of mass slowly movement in very wide area. Currently, it is
difficult to measure whole landslide area using existing landside displacement monitoring
systems. Because landslide displacement monitoring systems can measure at some points or
along lines. The ground based portable Laser Scanner has some advantages; wide area and high
resolution data can be obtained in a short time. Therefore, the ground based portable Laser
Scanner may be useful for landslide monitoring. However, portable Laser Scanner has a
problem for highly accurate measurement. Because, Laser Scanner does not have telescope for
collimation, then it is difficult to measure same points in each observation. To solve the problem,
the extraction of three dimensional objects from laser scanning data will be necessary to detect
landslide displacement. In this study, the method for measurement of landslide displacement by
object extraction with ground based portable Laser Scanner was discussed. For object extraction,
training data which were three dimensional object model by CAD will be compared with laser
scanning data. High accurate location of the training data were calculated by finding nearest
distances between Laser Scanner data and each surface of object model. After that, landslide
displacement will be detected by using time series data which extracted object. The object
extraction showed reliable result for monitoring landslide by comparing with survey data using
Total Station.
1. INTRODUCTION
Currently, Laser Scanner is expected in many fields. Because, it can acquire
three-dimensional data in a short time, in wide area. Therefore, Laser Scanner can be used for a
disaster prevention or 3D topographic surveying in high resolution. In case of measuring
movement phenomenon like landslide must be compared with same points in time series data.
However, measurement using Laser Scanner is difficult to compare same points in each
observation, because Laser Scanner has not telescope for collimation.
