抄録
The exact location of an excavating machine for allocating small size sewage pipes to be placed under the ground should be measured. A total station used to be applied for the traverse survey in case of larger size of pipes, but it would be difficult for those small size pipes as the total station could not be set in the small pipes. A special digital camera system with two cameras with forward and backward looking has been developed to measure the horizontal and vertical angle between the pipe units which made the traverse survey possible with high accuracy as the length of the pipe unit was precisely measured. However in order to achieve the required accuracy the camera calibration should be performed to assure the angle measurement accuracy. The paper describes the development of the special digital camera system, camera calibration and accuracy analysis.
