起算点坐标精度对高速铁路CP0框架网GAMIT基线解算结果的影响研究

Study on the Influence of Fixed Initial Point Coordinate Accuracy on GAMIT Baseline Solution Results of High-speed Railway CP0 Frame Network

根据GNSS相对定位双差观测方程推导了起算点误差对GPS基线向量的传播模型。以杭黄高速铁路CP0框架控制网作为研究对象,用试验的方法讨论了不同起算点坐标精度对高速铁路CP0框架网基线解算结果的影响。结果表明,在使用GAMIT软件处理CP0框架网基线向量时,必须严格控制起算点坐标精度,最好将其控制在10 cm范围内;当起算点初始坐标精度低至20 cm时,GAMIT软件解算的CP0框架网基线在X、Y、Z三个方向的分量可仍保持在mm级;但当起算点坐标误差达到2 m时,CP0框架网GAMIT基线解算结果无法满足高速铁路CP0框架网基线解算的精度要求。

Aiming at the influence of the fixed initial point coordinate precision on the baseline solution used by the GAMIT of the high-speed railway CP0 frame control network, the propagation model of the fixed initial point error to the GPS baseline vector is derived based on the GNSS relative positioning double-difference observation equation. Taking CP0 frame control network of high-speed railway as the research object, an experimental method is used to discuss the influence of coordinate accuracy of different fixed initial points on the baseline solution of GAMIT software for high-speed railway CP0 framework network. Results show that when using the GAMIT software to process the baseline vector of the CP0 frame network, the coordinate accuracy of the fixed initial point must be strictly controlled, which is best to control it within 10 cm. When the coordinate error of the fixed initial point reaches 20 cm, the resolution of the GAMIT baseline component of the CP0 frame network remains at the mm level. But when the coordinate error of the fixed initial point reaches 2 m, the GAMIT baseline solution result of the CP0 frame network is no longer reliable and cannot meet the high-precision requirements of high-speed railway CP0 frame network baseline solution.