Surveying method of points on axis of cyllindrical pipe

:To determine axes line of pipe or structural building which has a round normal section is recurrent in actual building works. The verticality measurement of chimney, TV tower and the deflection measurement of pipe are important to find out the deviation from design in construction, installation and completion. This paper discussed the measurement technique and data processing method for axes line of round normal section based on reflectorless distance measure. Simulation and practical results showed its feasibility and high efficiency.