LiDAR data in a local coordinate system may need to be georeferenced and converted into a geographic or projected system. In coordinate transformation, the 7-parameter Helmet
transformation method is usually used in measurements to eliminate the systematic errors made by a laser scanner. However, 7-parameter coordinate transformation assumes that there is only one scale error in all of the systematic errors. This study used 12 parameter affine transformation for coordinate transformation of airborne LiDAR data and terrestrial LiDAR data. The LiDAR data accuracy results
upon 6-parameter similarity transformation, 7-parameter similarity transformation, and 12-parameter affine transformation were compared. The results showed that using 12-parameter affine transformation the airborne LiDAR and terrestrial LiDAR data have 2-3 times greater accuracy than do 7-parameter or 6-parameter transformations.
Key Words : LiDAR, coordinate transformation, 12-parameter, affine transformation.
Department of Civil Engineering, National Chiao Tung University, Hsinchu, Taiwan, R.O.C.
Disaster Prevention Technology Research Center, Sinotech Engineering Consultants, Inc.
Department of Geomatics, Chien Hsin University of Science and Technology, Taoyuan County, Taiwan, R.O.C. * Corresponding Author. E-mail : Kenwu@uch.edu.tw