Abstract
This paper describes an accurate long-distance position measurement system using laser range finders, and application of construction foundation work. Since the LRF is a sensor which can measure distance to surfaces of objects by radiating laser beams from itself and receiving the reflected ones, an obtained data from the LRF are nothing more than the contours of objects. Therefore, as the survey target, we adopted the cylindrical shape object that was invariant against rotation, and the center position of the circular arc was analyzed by applying the least square method and maximum likelihood estimation. The error between the analysis and the measurement was corresponds enough to the allowable accurate range. Additionally, improving the angular resolution of the LRF by using a pan unit, the highest accurate center position was able to acquire. Applying this system to the construction work, the high accurate pile marking and pile drive positioning were recognized. Since this measurement was achieved by only a worker and the position and direction of the worker was easily found, the high efficient and short term works were surely performed
