The Establishment of D, E Grade GPS Control Network and Fourth-Order Leveling Network in Laicheng Industrial Zone of Laiwu City

The paper uses D level,E level and the level of GPS control network establishment satellite space geodetic network in Laicheng industrial zone in Laiwu, through the baseline calculating, three-dimensional unconstrained adjustment and two-dimensional constraint adjustment to get the WGS-84 three dimensional coordinates and 1980 xi 'an horizontal coordinatesthe of control points; then using the fourth-order levelling connection survey all D-level, E-level control points and part GPS control points to build vertical control network, for the GPS control points of the remaining we utilize quadric function method using GPS elevation fitting given its elevation seek to obtain three-dimensional coordinates of all the basic control points.