PPP技术在无基准或多基准测区应用研究

Application of PPP technology in non-datum or multi-datum survey area

在无基准或者多基准测区建立首级控制网时,进行控制点联测将耗费大量的精力,且累积误差较大,采用精密单点定位(PPP)技术可有效解决问题.基于GrafNav软件PPP解算大量的IGS站数据和实测数据,得出PPP解平面误差小于1 cm,高程误差小于10 cm的结论,同时测段超过4 h时PPP解算误差变化较小,且时段越长解算精度稳定性越好.而多基准测区进行基准变换时,历元变换对Y方向的影响较大,基准变换的精度受测站位移变化值的影响较大.

When setting up the first-level control network without reference or multi-reference measurement area,the joint measurement of control points will consume a lot of energy,and the cumulative error is large.The precise single-point positioning(PPP)technology can effectively solve the problem.Based on a large number of IGS station data and measured data calculated by GrafNav software PPP,it is concluded that the plane error of PPP solution is less than 1 cm and the elevation error is less than 10 cm.At the same time,when the measurement period exceeds 4 hours,the variation of PPP solution error is small,and the longer the period,the better the stability of the solution accuracy.However,when the datum transformation is performed in the multi-reference measurement area,the epoch transformation has a great influence on the Y direction,and the accuracy of the reference trans-formation is greatly affected by the displacement variation value of the station.