CPⅢ精密三角高程控制网精度影响因素分析

Analysis of Factors Influencing the Accuracy of CPⅢPrecise Trigonometric Vertical Control Network

为了进一步提高CPⅢ精密三角高程控制网的精度,从精密三角高程测量模型入手,分析了控制网精度影响因素,并基于仿真计算,分析了各因素的影响规律.结果表明:影响CPⅢ精密三角高程控制网精度的主要因素是大气折光和地球曲率、测角误差以及高山区观测目标与测站之间垂线偏差的变化;基准点间距每增加0.5 km,CPⅢ点高程中误差降低约0.1 mm左右,但基准点间距的变化,对相邻CPⅢ点间高差精度的影响可忽略不计.

In order to further improve the accuracy of CPⅢprecise trigonometric height control network,this paper starts with the precise trigonometric height measurement model,then analyzes the influencing factors of the accuracy of the control network.Based on the simulation calculation,the influencing rules of each factor are analyzed.The results show that the main factors affecting the accuracy of CPⅢprecise trigonometric height control network are the influence of atmospheric refraction and earth curvature,the error of angle measurement,and the change of vertical deviation between the observation target and the observation station in the high mountain area;the mean square error of CPⅢelevation decreases by about 0.1 mm for every 0.5 km increase in the distance between datum points.However,the influence of the distance between datum points on the accuracy of height difference between adjacent CPⅢpoints can be ignored.