Dependency of strains and rotations in geodetic network

At each point of the geodetic network, kinematic\ud quantities are considered: normal strain, shear\ud strain and rotation. This differs from the treatment\ud of deformations on the basis of point movements as\ud the traditional geodetic approach. Strain and rotation\ud depend on the changes of geodetic datum. In the case\ud of two different coordinate systems in each epoch,\ud we cannot calculate the real value of movements,\ud strains and rotations. Despite the empirical studies\ud of the datum invariance, we derived analytical\ud mathematical expressions of functional dependency\ud of strains and rotations from the relative change of\ud datum parameters between two measurement epochs.\ud Practical demonstration of functional dependencies\ud has been shown in the case of the selected planar\ud geodetic network

TPS and TLS laser scanning for measuring the Inclination of tall chimneys : TPS i TLS lasersko skeniranje za određivanje vertikalnosti visokih dimnjaka

The verticality of tall chimneys needs to be accurately monitored. Vertical plumbing, the classic geodetic procedure for detecting the inclination has certain drawbacks and can be replaced by modern technology if necessary. It was proposed a more general and rigorous procedure. For the researching it was used laser scanning methods which result in point clouds. Data acquired with two types of laser scanners were fit to a cylinder using the least squares adjustment. The aim of the paper was also to point out the differences between the used technologies, the differences between the results as well as influences on the computed inclination of the chimney and its practical explanations

Determination of the nonverticality of high chimneys

This article deals with practical examples of the applications of modern tachymeters in the determination of the nonverticality of high industrial chimneys, as an alternative to the classic methods. The possibility of a reflectorless measuring mode to determine the point cloud at the chimney's circumference is described. Using these points, we are able to model the chimney as a mathematically correct body using the least squares adjustment method. Subsequently, the unknown nonverticality of the chimney is determined as the deviation of the primary axis of the modelled body from the vertical

Geodetic measurement of distances in athletics

Geodetic measurements are indispensable beyond the borders\ud of surveying technical tasks. In this paper, the usefulness of\ud geodesy in the measurement of sport results is described for\ud throwing events, in accordance with the rules accepted by\ud the IAAF. The article focuses on terrestrial measurements\ud and geometric solutions for the determination of the result\ud of an athlete in the javelin, hammer and discus throw and\ud shot putt. Some effects on measurements within the specified\ud precision of the result are studied. We analyse the influence\ud of ground inclination and gravity on the sport result and the\ud influence of the location of the instrument on the precision\ud of the length of throw

Deformation analysis: the DELFT approach

The Delft approach, a method for the deformation\ud analysis, is presented in this article. Based on\ud geodetic measurements, the statistical significance\ud of displacements at the surface is determined with\ud statistical methods. A numerical example shows the\ud effectiveness of the presented method

Use of Automatic Target Recognition System for the Displacement Measurements in a Small Diameter Tunnel Ahead of the Face of the Motorway Tunnel During Excavation

During construction of the Sentvid tunnel a unique opportunity arose to measure the 3D displacements ahead of the motorway tunnel excavation face, since the exploratory tunnel was already constructed in the axis of the main tunnel. According to reviewed literature such measurements had not been performed yet and several problems regarding equipment and complete scheme of the experiment needed to be overcome. The paper gives a brief description of the Sentvid tunnel project, presents significant factors that affected the choice of the geodetic equipment and describes the scheme of the experiment. A special attention is focused on the problems relating to the operation of the instrument in demanding environmental conditions (water, dust)

Statistical Properties of Strain and Rotation Tensors in Geodetic Network

This article deals with the characteristics of deformation of a body or a figure represented by discrete points of geodetic network. In each point of geodetic network kinematic quantities are considered normal strain, shear strain, and rotation. They are computed from strain and rotation tensors represented by displacement gradient matrix on the basis of known point displacement vector. Deformation analysis requires the appropriate treatment of kinematic quantities. Thus statistical properties of each quantity in a single point of geodetic network have to be known. Empirical results have shown that statistical properties are strongly related to the orientation in single point and local geometry of the geodetic network. Based on the known probability distribution of kinematic quantities the confidence areas for each quantity in a certain point can be defined. Based on this we can carry out appropriate statistical testing and decide whether the deformation of network in each point is statistically significant or not. On the other hand, we are able to ascertain the quality of the geometry of the geodetic network. The known characteristics of the probability distributions of two strain parameters and rotation in each point can serve as useful tools in the procedures of optimizing the geometry of the geodetic networks

Geodetic measurements in tunnel Šentvid

This article describes the geodetic monitoring of the\ud impact that the tunnel excavations have on the rock\ud mass at the tunnel face in the Šentvid tunnel. In the\ud preliminary phase, an exploratory gallery was built\ud almost along the main tunnel axis to collect geological,\ud tectonic zone and other relevant data. The exploratory\ud gallery is now being used for geodetic and other\ud monitoring of the impact of tunnel excavations on the\ud surrounding rock mass. Before the beginning, methods\ud of point and station point stabilization, and a\ud measurement method were chosen. Thus, the chosen\ud methods are the method of 3D inner intersection with\ud adjustment of redundant observation for station point\ud determination, and the polar method for calculating\ud 3D coordinates of detail points. The method of\ud determination of station point was chosen because of\ud the far reaching influence that the tunnel excavations\ud have on rock mass behaviour at the tunnel face

Datumska odvisnost deformacij in rotacij geodetske mreže ; Datum dependency of strains and rotations in geodetic network

V vsaki točki geodetske mreže obravnavamo kinematične količine: normalne deformacije, strižne deformacije in rotacije. Pristop se razlikuje od tradicionalnega geodetskega načina obravnave deformacij na podlagi premikov točk. Deformacije in rotacije so odvisne od spremembe geodetskega datuma. V primeru različnih koordinatnih sistemov v posamezni izmeri ne moremo izračunati pravih vrednosti premikov, deformacij in rotacij. Kljub že opravljenim empiričnim študijam o odvisnosti od datumskih sprememb smo analitično izpeljali matematične izraze odvisnosti deformacij in rotacij od relativne spremembe datumskih parametrov med dvema terminskima izmerama. Praktični prikaz funkcijske odvisnosti je bil izveden na primeru izbrane ravninske geodetske mreže ; At each point of the geodetic network, kinematic quantities are considered: normal strain, shear strain and rotation. This differs from the treatment of deformations on the basis of point movements as the traditional geodetic approach. Strain and rotation depend on the changes of geodetic datum. In the case of two different coordinate systems in each epoch, we cannot calculate the real value of movements, strains and rotations. Despite the empirical studies of the datum invariance, we derived analytical mathematical expressions of functional dependency of strains and rotations from the relative change of datum parameters between two measurement epochs. Practical demonstration of functional dependencies has been shown in the case of the selected planar geodetic network