Research on geo-referencing methodology of point cloud data

The Terrestrial Laser Scanner (TLS) has been widely used in many engineering fields because it provides us with direct measurement of 3D information of objects with high resolution and reliable accuracy. The TLS measures distances and angles from the sensor to the reflecting target, and only the relative positions are recorded. Thus, geo-referencing of point cloud data is required to provide the products with their absolute position in the real world. In the past, geo-referencing of point cloud data was achieved by using a total station. Firstly, the surveyor conducted a control survey by using a GPS, and set up the total station at the control point. The surveyor attached the special target on the surface of the object, and measured the absolute position of it. Then, the geo-referencing was conducted through post-processing. However, this conventional process requires too much time, and errors in total station are propagated to the coordinates of the point cloud data. In the current study, we suggest a new methodology which simplifies the geo-referencing process by integrating the GPS and targets. It is expected that a great deal of time and cost can be saved by implementing our suggested methodology.