控制网选点系统的研究

为适应城市、工矿地区测图和各种工程的需要，无论采用GPS观测或是常规控制方法观测均需要建立一定精度和密度的控制网。根据任务要求，拟定合理的观测方案，在图上设计出一个图形结构较强、点位分布较好的网形。设计好的控制网，是否合乎实际，还需要到实地验证，最终确定控制点的适宜位置。在Visual Basic设计的选点系统里，对控制网的精度与可靠性进行估算，用AutoCAD读入地形图再一次进行图形的编辑与精度查看。正是由于省掉了不必要的选点工作，使得选点工作变得更具条理性。同时网点总数的降低，也节省了一定的经济开销．所以本系统具有一定的经济价值。

Research on the Site Selecting System of Control Network

In order to meet the requirements of urban and mineral region surveying, and various engineering, we need establish the control network of certain accuracy and density no matter using GPS surveying or traditional control surveying method. According to the task requirement,we should draw a reasonable observation plan,and design a control network with strong geometric structure and good distribution of point site. To verify the designed control network,we have to implement the validation in the field and determine the optimal site of the control points. In the location selecting system which is programmed using Visual Basic,it estimates the precision and reliability of the control network, and imports the topographic map into the system by AutoCAD, then carries on editing the network and examines the accuracy again. Because of saving the nonessential site selecting work,the site selecting work becomes more consecution. The system has certain economic value because it can decrease the total number of control points to save economical expenses.