The establishment of a reference geodetic network made of closed polygonometric quadrangles and designated for landslide slopes

Introduction. A reference geodetic network in the form of a closed polygonometric quadrangle is established at the Karamyshevsky landslide slope in Moscow for the purpose of repeated geodetic observations of landslide displacements. The purpose of the study is to show that the reference geodetic network in the form of closed polygonometric quadrangles can be implemented for landslide slopes along with other linear and angular methods. Materials and methods. Accurate or high-precision electronic total stations, such as Leica, Sokkia, Topcon, etc. are used to take field measurements. In this case, all four corners and all four sides are to be measured. There are three redundant measurements in this polygon of polygonometry to ensure the reliable control of the field work quality. It is advisable to equalize this polygon using the correlate type of the least squares method for the two reasons. First, to calculate the acceptable residuals, it is necessary to make an appropriate conditional equation, i.e. implement the most important and time-consuming part of the correlate method algorithm. Second, in the process of the algorithm implementation, the correlate method allows to obtain the inverse weights of equalized measurements, whose comparison with the inverse weights of unbalanced measurements provides a visual representation of the quality of the geometry of the designed network. Results. The mathematical processing of the results of geodetic measurements of the reference network in the form of closed polygonometric quadrangles using the method of least squares is quite complex and requires a computer technology and appropriate software. However if they are available, the problem is solved unambiguously and very accurately, which particularly important. Conclusions. The construction of reference geodetic networks in the form of closed polygonometric quadrangles for observing landslide displacements can be recommended for other landslide slopes.