Application And Study Of GPS Technology In Plan Controling Net

In our country, the first degree for controlling nets of GPS is C in many middle and big cities, which main purpose is to develop the basic control nets and to give service for construction and layout. The main characters of these nets are the followings: the region controlled is limited; and have short baseline; time for measuring is short. The technology to make city horizontal control nets are gradually displaced by GPS technology in our country, because of its characters of high precision, fast speed and low cost, and so on. That is to say that GPS technology is displacing the common ways to survey angels and distances to develop the horizontal control nets in many middle and big cities. Because the ways to make GPS control nets are so random that different companies have different understandings to the specifications of surveys, many horizontal control nets in many big cities have some fault.In this article the author discusses a series processes in detail from GPS control nets layout, selecting coordinate system and checking the raw datum to survey and adjustment and so on. The paper also makes deeply research on the lack of coordinate system choosing and the replace region, because many companies for production only pay more attention on measuring and computing when they make the control nets.According to the research on the GPS control nets in LASA, the conclusion is that it is an effective way to control the length deformation through choosing a proper central meridian and basic project plane according to the different location is generated. At the same time, other research on the followings: how to choose a proper replace project plane, discussing replace region, making out reference ellipsoid parameters, transferring the geodetic coordinate system to the regional coordinate system, seeking for the proper way to choose coordinate system.According to the research on the second degree GPS control nets of WeiHai, a fully and systemic account is generated from layout, choosing a coordinate system and checking the original datum to the objection and adjustment computation. According to the research on the problem of height fitting in the GPS control nets of WeiHai, some facts are made by author as the followings: what is the region the height fitting is for, how to select the proper height...