G1501-3-2 Study on an Error Eliminating filter using dynamic threshold for the Three Dimensional Position Surveying System for the Underground Pipes

Optical fiber cable for high-speed and large-capacity communication is usually covered by plastic pipe and buried under the ground. Then, we are required to grasp its real buried position before digging at the maintenance in order to prevent from the cutting of the optical fiber. This research aims to identitv easily the buried position of the pipe, using the information of the buried position from the pipe. It is confirmed that the new position surveying system can identify the buried position of a pipe that is 20 m long and has loose three-dimensional curvature in the error of 39 mm