千寻位置在铁路勘测中的应用研究

为了发挥千寻位置服务的优势和特点,拓展其在铁路勘测及运营全过程中的应用,利用"千寻知寸"服务,研究在已建立勘测控制网区域内进行铁路勘测的应用方法。其基本思想为:通过已知的当地坐标和千寻位置采集的大地坐标,建立点校正,直接实现坐标转换,在控制点的检核满足限差要求后,开展勘察测量工作。分析了"千寻知寸"在铁路勘测中的定位精度以及测量点位的误差传递规律,并结合项目实例验证了所提应用思路的可行性。结果表明:"千寻知寸"可为铁路勘测提供厘米级的定位精度,满足常规铁路的勘测需求;但其测量精度受既有基线测量误差的影响,离起算点越远误差越大,在使用过程中应合理选择起算点;以"千寻知寸"RTK测量的结果解算控制网各控制点坐标,平面及高程方向分别存在约2 cm和3 cm的固定误差。

Research on the Application of the Qianxun SI in the Railway Survey

In order to give full play to the advantages and characteristics of the Qianxun SI and expand its application in railway survey and operation,this paper utilizes the Qianxun SI service to study the specific process of railway survey in the area where the survey control network has been established.The basic idea is to establish point correction based on known local coordinates and the geodetic coordinates collected by the Qianxun SI,and directly implement coordinate conversion.After the check of control point meets the tolerance requirements,survey and measurement work is carried out.The positioning accuracy of the Qianxun SI in railway surveys and the law of error transmission of measurement points are analyzed,and the feasibility of the proposed application idea is verified with a project example.The results show that the Qianxun SI can be applied to railway surveys to provide centimeter-level positioning accuracy and meet the needs of conventional railway surveys;however,the measurement accuracy is affected by the existing error of the baseline measurement,and the error will increase with distance from the starting point,thus the starting point should be selected reasonably during use;the coordinates of the control points of the control network are solved by the results of the Qianxun SI RTK measurement,and there would be fixed errors of about 2 cm and 3 cm in the plane and elevation directions.