Three-Dimensional Adjustment of Precision Control Network Based on Independent Coordinate System

The control network measurement system based on Railway fixed pile can be used in the maintenance of ballasted track. However, how to evaluate the impact of the external observation precision of the control network on the relative position precision and the position precision of the control point does not have a final conclusion. This paper combines line field conditions of Railway line. We have proposed a net-shaped and analysis of field data collected on the basis of three-dimensional control point adjustment calculation. And then, we can get the relation among field observation precision of control point and relative positional precision and positional precision of the control point. The result shows that if the azimuth measurement accuracy is less than ±1¢¢ , the accuracy of the vertical measurement and the distance measurement are less than ±1¢¢ and ( ) 6 2 2 10 mm − ± + × , respectively. And then the relative position accuracy of control network will be less than ±4mm . The conclusion plays an important role in the ballasted track measurement standard and work.