The study raises the issues concerning the automatic system designed for the monitoring of movement of controlled points, located on the roof covering of the Forest Opera in Sopot. It presents the calculation algorithm proposed by authors. It takes into account the specific design and location of the test object. High forest stand makes it difficult to use distant reference points. Hence the reference points used to study the stability of the measuring position are located on the ground elements of the sixmeter-deep concrete foundations, from which the steel arches are derived to support the roof covering (membrane) of the Forest Opera. The tacheometer used in the measurements is located in the glass body placed on a special platform attached to the steel arcs. Measurements of horizontal directions, vertical angles and distances can be additionally subject to errors caused by the laser beam penetration through the glass. Dynamic changes of weather conditions, including the temperature and pressure also have a significant impact on the value of measurement errors, and thus the accuracy of the final determinations represented by the relevant covariance matrices. The estimated coordinates of the reference points, controlled points and tacheometer along with the corresponding covariance matrices obtained from the calculations in the various epochs are used to determine the significance of acquired movements. In case of the stability of reference points, the algorithm assumes the ability to study changes in the position of tacheometer in time, on the basis of measurements performed on these points.