摘要
本文介绍了应用GPS技术对上海城市平面控制网的改造方案。基线由GAMIT软件解算 ,利用空间平差模型进行了三维坐标平差 ,平面平差则在不同的条件下进行。在上海平面坐标系统平面平差时 ,采用原点不变并固定部分稳定控制点坐标值的方法 ;在 195 4北京坐标系和西安 80坐标系平面平差时 ,采用原有坐标控制点坐标改正数之和为零的条件 ,保证了GPS网的内部一致性。通过对新旧控制网的精度进行比较表明 ,改造后网的精度大大优于原控制网 ,能适应现代高精度大型工程控制网的需要。最后利用七参数转换方法计算了各个坐标系之间的转换关系。
The GPS technique is used to rebuild the first-order control network for Shanghai city.The baseline vectors are solved with software GAMIT and the space coordinates determined with 3-D adjustment model.Horizontal coordinates are adjusted under different conditions.For Shanghai local coordina te system,the origin is keeping the same.For Beijing 54 and Xi′an 80 coordinate systems,the sums of coordinate change of existed points equal to zero as the con dition adopted,which can keep the internal consistency of the GPS network.Specif ic analysis shows that this network can satisfy the accuracy demand for modern l arge engineering control network.The related transformation parameters are solve d within the coordinate systems.
出处
《工程勘察》
CSCD
北大核心
2004年第5期50-52,共3页
Geotechnical Investigation & Surveying
关键词
GPS控制网
改造
平差
GPS control network
rebuilding
adjustment
