重力异常改正在山区铁路工程控制网二等水准复测中的应用

High-difference Gravity Abnormal Modification is Being Applied in a Bid Section of the Sichuan-Tibet Railway

川藏铁路高差起伏大,横断山区重力异常及其变化大,重力异常改正值远远大于测量误差,从不同水准路线进行环线闭合,必须进行水准面不平行改正、重力异常改正。通过工程案例可以看出,重力异常改正在二等水准网观测计算中至关重要。

The height difference of the Sichuan-Tibet Railway fluctuates greatly,and the gravity anomalies and changes in the cross-sectional mountainous areas are large.The correction value of gravity anomalies is much greater than the measurement error.If the loop is closed from different levels of routes,the level surface must be corrected in parallel,including the correction of high-difference gravity anomalies.