The Control Nework's Automatically Designed Based On GIS

The flow of Control Surveying is mainly divided into three processes, namely, technical design, field surveying and indoor works. At present, the digital mapping technology has been mature; Meanwhile,a variety of data-processing softwares are used in the indoor works,making this process basicly digitized too. However, the design and optimization of the controling network is an important aspect during the surveying flow and besides,is the final part has yet to achieve digitalization and automation. Especially today,as a result of the GPS and other new technologies were widely used, the limitations of traditional measurement tools have become increasingly prominent. Therefore,the automation of the controling network design and optimization has great significance. In this regard, scholars at home and abroad carried out widespread and profound study, and achieved fruitful results, however, they did not make a complete flow system though their studies.After reading some related research papers and a whole study of the principles and methods of controling network,the writer probes into the technologies of GIS -based automatical place-selecting , automatical network building and tentative precision estimation of the controling network. Moreover, the paper discusses the new methods of automatically controling network design and optimization based on GIS technology, which used the main technical methods of digital terrain analysis and due to the digital elevation model (DEM).Finally,use the Traverse Network and Triangle Network as examples, select the traverse points in the testing area through DEM extracted data features of the ridge line by programming, set the incidence matrix, and then realize the automatical building of the controling network. Meanwhile the Monte Carlo method is used to get tentative precision estimation of the controling network,thus verified the correctness and feasibility of the theory and the relative methods.