Abstract
The cross-hairs reticles of non-prism total stations cannot accurately measure the target on the objects which don't have a mark to put the cross-hairs on. Especially, it is too difficult to measure the centers of cylindrical structures. In this research, we propose to use a concentric reticle, the Baum, instead of the conventional cross-hairs reticles, and estimated the error from experiments. Total stations equipped with the Baum can measure the cylindrical structures. By measuring two points on the center, the tilt and the position of the axis can be measured, Applying this technology to driving pile, we have developed a navigation system for driving tilted piles which had been difficult to control their operation. The numerical value of to what degree the angle and distance should be adjusted is displayed from the operator's view. Also, the operation history can be recorded.