基于全球定位系统(GPS)控制网的技术,咸阳市对旧有城市控制网进行了改造和扩建。首先布测C级网,在其基础上再布测D级网。基线解算方面,在GPS网三维无约束平差的基础上,结合人工干预的方法剔除粗差,使之可以到达C级GPS网的测量精度要求,能够满足城市建设、城市规划对测量成果的需求。 Based on the global positioning system (GPS) control network technology, Xianyang City, the old urban control network has been transformed and expanded. First cloth test C-class network, and then on the basis of cloth test D class network. Baseline solution, based on the GPS network three-dimensional unconstrained adjustment, combined with manual intervention method to eliminate the gross error so that it can reach the C-level GPS network measurement accuracy requirements to meet the urban construction, urban planning on the measurement results demand.