@inproceedings{oai:kutarr.kochi-tech.ac.jp:00000898,
 author = {Miyazaki, Tomonori and Kinoshita, Kazu and Takagi, Masataka},
 book = {Society for Social Management Systems Internet Journal},
 issue = {1},
 month = {Mar},
 note = {Landslide is a phenomenon of mass slowly movement in wide area. It is difficult to measure whole landslide area by using existing monitoring systems. Nowadays, ground based portable the laser scanner is expected to monitor landslide, because the laser scanner can acquire three-dimensional data of wide area in a short time. The acquired data by the laser scanner has own coordinates. The coordinate is called laser coordinate in this study. The laser coordinate must be transformed into the ground coordinates using Ground Control Point(GCP). The prism or reflector sheet is usually used as GCP. GCPs of ground coordinate can be precisely measured by total station. The laser coordinates of GCPs can be acquired automatically by image processing software of laser scanner. The image processing is based on reflection strength of the laser around the prism or reflector sheet. The reflection strength of the prism is higher than reflector sheet. Then prism can be set up widely. However, cost of the prism is so expensive that many prisms cannot be set up. On the other hand, cost of reflector sheet is so cheap that many reflector sheets can be set up. Therefore, the prism and the reflector sheet should be compared in order to establish accurate transformation method. In this study, 6 prisms and 16 reflector sheets were used for geometric transformation. The accuracy of geometric transformation was discussed. The required accuracy is 10mm of Root Mean Square Error(RMSE) for land slide monitoring. In the case of prisms, result showed 95.9mm RMSE. In the case of reflector sheets, result showed 25.0mm RMSE. Many reflector sheets were effective for accurate transformation. Repeat measurement will make accurate transformation by average calculation. The average calculation of 10 times measurement showed 5.4mm error. Therefore, this measurement method will be effective to monitor land slide.},
 publisher = {Society for Social Management Systems},
 title = {Accurate Geometric Transformation of Laser Scanner Data for Landslide Monitoring},
 volume = {4},
 year = {2008}
}