基于CPⅢ控制网进行仪器加乘常数的计算方法研究

A Study on Computing Method of Instrumental Addition and Multiplication onstant Based on CPⅢControl Network

针对仪器加乘常数计算方法进行研究,旨在基于高精度CPⅢ控制网和六段法得出一种便于计算仪器加乘常数的方法。首先,本文对CPⅢ控制网自由网平差中四参数转换尺度因子的主要影响因素进行分析;接着,对铁路工程控制网独立坐标系进行变形分析,表明以铁路坐标系统设计上相对应的投影变形值可以进行严格的投影改正;之后,通过以严格投影改正后数据处理得到的CPⅢ控制网结果为基础构建六段法求解仪器加乘常数;最后,对本文提出的方法进行实验验证,其结果表明:在进行严格投影改正后,由测距误差综合引起的自由网平差中四参数转换中的尺度因子值大小相当;基于高精度CPⅢ控制网构建六段法计算仪器加乘常数的方法正确、可行。

This paper proposes a study on the computing method of instrumental addition and multiplication constant based on high-accuracy CPⅢcontrol network and six-range method.Firstly,this paper introduces the CPⅢcontrol network,and analyses the main factors of scaling factor for four-parameter transformation model in free network adjustment.Meanwhile,the paper analyzes deformation of railway engineering control network in independent coordinate system,which shows that the projection distortion value corresponding to the design of the railway coordinate system can be rigorously corrected.Then,based on the CPⅢcontrol network results obtained by data processing with rigorous projection correction,the six-range method can solve the instrumental addition and multiplication constant.Finally,the method proposed in this paper is experimentally verified.The conclusion is that the scaling factor value caused by integrated ranging error for four-parameter transformation model in free network adjustment is equivalent after rigorous projection correction.The six-range method of computing instrumental addition and multiplication constant based on high-accuracy CPⅢcontrol network is correct and feasible.