THE STUDY OF CONSTRUCTION OF PRECISIONAL GEODESIC NETWORKS BY COMBINED METHOD OF STATIC AND RTK GNSS MEASUREMENTS

The RTK method of determining the coordinates involves the use of two receivers: the basic - with known coordinates and rover - the coordinates of which are determined. We offer to use the base and two rovers that work simultaneously. With this method, systematic and random errors contained in measurements for different eras by one rover should be excluded from observations. The proposed goal can be realized by joint processing of vectors determined by static technology and a network of simultaneous RTK measurements. The method offers two criteria for assessing the accuracy of vectors:

- differences between reference and measured constituent elements of vectors;

- a posteriori optimization of combined GNSS networks (Tretyak, 2003).

Studies of the accuracy of determination of spatial vectors in the RTK mode were performed at the geodynamic landfill of the Dniester PSP (Fig. 1 a). The landfill is located in Ukraine, consists of 49 points, which are located in different conditions of visibility of satellites, rugged terrain and vegetation. The centers of the points are fixed by a metal plate with a hole that provides a centering error within 0.05 mm. At these points, long-term observations of satellite technology in static mode are performed annually. In the cycle of observations, each vector is determined 2 - 3 times, using 8 - 10 multifrequency receivers. Thus, about 700 vectors are determined, optimized and balanced. A large number of redundant measurements guarantees the accuracy of determining the centers of the holes of the signs of 1 mm, which is an estimate of the balance of the network. Therefore, the increments and lengths of vectors determined by spatial coordinates can be taken as reference.