The Use of Free Adjustment and Msplit-Estimation for Determination of the Vertical Displacements in Unstable Reference System

The problem of the determining of the displacements of engineering objects and their surroundings is the current and important issue in the field of engineering geodesy. Most control measurements are made in relation to reference points (stable points). On the other hand, sometimes it happens that it is not possible perform the measurements with reference to the stable points or identification of stable points is difficult. Therefore, one of the solutions may be the determination of displacements in unstable reference system. One way to solve this problem with using Msplit estimation is presented in [11]. The author of the paper [11] conducted an analysis of the acceptance of erroneous assumptions about the stability of the reference point. In this paper the authors proposed the calculation algorithm that takes into account the use of free adjustment and Msplit estimation to determine the vertical displacements of controlled points.