Application Research On The Teamwork Of Different GPS Receivers In The Highway Control Network Resurvey

Since the highway construction is a long-term project, control point will be moved or damaged due to outside influence in the whole construction process. Therefore, in the process of highway construction, it is necessary to resurvey the control network periodically and update and maintain the control point in time. GPS technology has been widely used in highway control survey with its characteristics of all-weather, high precision and automatic measurement. In the actual control network survey,it is need to use different instruments for static relative positioning because of the limit of the number of instruments. Since there are some differences in the measurement results of different GPS receivers, which affect the accuracy of GPS network, it is necessary to study and analyze the teamwork of different GPS receivers in highway control network resurvey.It has important significance for improving the survey efficiency,solving practical engineering problems and theoretical research on the application of GPS. In this paper, taking the GPS control network resurvey of the seventh section of Wanli Expressway(Wanzhou section) as an example,the teamwork of different GPS receivers is studied. The main jobs in the process of the study are as follows.(1) Summarized the knowledge involved in the process of GPS control network resurvey;mainly analyzed the principle of coordinate transformation,the Gauss projection,three-dimensional unconstrained adjustment and two-dimensional constrained adjustment;derived the relevant formulas.(2) Arranged field observation data and classified the measured data by the types of GPS receiver. In indoor processing, the measured data were processed and comprehensive inspected with the Haida HDS2003 data processing software.Matlab, Pinnacle and Haida HGO were also used as a supplement. The joint measured data of different GPS receivers were first processed in the process of data processing,then the separate measured data of each type of GPS receivers. The two treatment results were compared and the causes of the differences were analyzed with the actual situation of field observation and the related theory.(3) The stability of resurvey points were analyzed with the reference approaches of relevant specification and mean error checking.At last, the constrained adjustment results of the separate measured data of each type of GPS receivers were used as a basis for judging the stability of control network.Through the application and research of the entire process, including design, implementation of the resurvey scheme and the data processing,the problems in the Wanli Expressway(Wanzhou section) Section 7 control network resurvey which were operated with different GPS receivers were solved. Also the accuracy of measurement were guaranteed and the stability of control points were evaluated. The conclusion of this paper can provide guidance for renewal and maintenance of the control points in this project, but also can provide a reference for other similar GPS control network survey.