Method of Landslide Measurement by Ground Based Lidar

Landslide is a phenomenon of mass movement of terrain. In order to prevent landslide, understanding the behavior of the landslide is important. The behavior of the landslide is usually measured by extensometer, inclinometer or GPS (global positioning system). These equipments are measuring some points or along the lines; it is difficult to measure the whole landslide area. Currently, it is expected that ground based LiDAR can be used to monitor the whole landslide area, because the LiDAR can acquire threedimensional data of wide area in a short time. The acquired time series data should be analyzed to measure the land movement to understand the behaviour of the landslide. Author report the method of landslide measurement with a LiDAR based on the best past results of the research. For accurate measurement, surface of flat plane should be used. At least 256 points or more points are used in surface measurement, the error margin produced less than 1cm. When, the object surface is small, repeat measurement will be effective. Next, materials or GCP were evaluated. The result showed reflector sheets had accurate than the prism. Acquisition of the vicinity of the center of coordinates in the method used the averaging weight of reflection strength in selection of GCP. When the position of the LiDAR was setup on a fixed place, the transformation model must be fit to the situation and it is established. Method of the object matching for landslide monitoring is developed using these data, and the displacement extraction of the landslide will be able to present in future.