Analyzing Object Verticality: A Three-Segment Linear Regression Model

When inspecting the stability of tall slender structures like towers, chimneys, masts, or skyscrapers the main stability criterion is the object’s inclination. Geodesy plays an important role in the process of structural health monitoring of these objects. Geodetic engineers use various types of measurements (classical distance and angle measurements, height differences) and methods (global navigational positioning system, photogrammetry, laser scanning, etc.) to inspect the verticality of these objects. In this paper, a method based on terrestrial measurements by a total station and linear regression model was used to inspect the verticality of the steel grid pillars in the Sarajevo region. To assess a 3D vector that describes the verticality of the object by classical linear regression, a three-segment linear regression model was introduced in this research. The complete procedure of acquiring the data, processing data, and assessing the accuracy of the obtained results is described in this paper. The results showed that the proposed approach based on a three-segment linear regression model and terrestrial reflectorless observations can provide accurate and reliable results in inspecting the stability of steel grid pillars.