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Dams play a pivotal role in providing essential services such as energy generation, water supply, and flood control. However, their stability is crucial, and continuous monitoring is vital to mitigate potential risks. The Mosul Dam is one of the most interesting infrastructures in Iraq because it was constructed on alternating beds of karstified and gypsum which required continuous grouting due to water seepage. Therefore, the ongoing maintenance issues raised international concerns about its stability. For several years the dam indicated a potential for disastrous failure that could cause massive flooding downstream and pose a serious threat to millions of people. This research focuses on comprehensive statistical assessments of the dam geodetic network points across multiple epochs of long duration. Through the systematic application of three statistical tests and the predictive capabilities of the Kalman filter, safety and long-term stability are aimed to be enhanced. The analysis of the dam's geodetic network points shows a consistent trend of upstream-to-downstream movement. The Kalman filter demonstrates promising outcomes for displacement prediction compared to least squares adjustment. This research provides valuable insights into dam stability assessment, aligns with established procedures, and contributes to the resilience and safety of critical infrastructure. The outcome of this paper can encourage future studies to build upon the foundation presented. [ABSTRACT FROM AUTHOR]

This study investigates panorama photogrammetry (PPh) as a potential method to collect massive 3D information for long-range deformation monitoring. Particularly, this study focuses on areas with measuring restrictions, i.e., inaccessible objects and distances above 0.6 km. Under these particular conditions, geodetic techniques based on Electromagnetic Distance Meters (EDMs) or Total Stations (TSs) can provide coordinates with a precision better than 1 cm, but only for a limited number of discrete points. For mass capture, Terrestrial Laser Scanning (TLS) is normally the preferred solution, but long-range instruments are expensive, and drawbacks such as weak return signals and non-automatic target recognition appear. As an alternative, PPh is investigated in the well-controlled area of La Muela in Cortes de Pallas, where images are automatically captured from geodetic pillars using a GigaPan device, processed, and then rigorously compared to TLS point clouds. The results obtained after integrating both techniques into a high-accuracy geodetic reference frame show that PPh and TLS provide similar precision to within approximately 4 cm in the range of 0.6–1.0 km. Therefore, considering cost-effectiveness and ease of use, the proposed method can be considered a low-cost alternative to TLS for long-range deformation monitoring. [ABSTRACT FROM AUTHOR]

The optimization of measurements in a geodetic network (second-order design) has been investigated in the past; however, the practical usability of the outcomes of most of such studies is doubtful. Hence, we have proposed a new automated optimization algorithm, taking into account the practical aspects of total station measurements. The algorithm consists of four parallel partial algorithms, of which one is subsequently automatically selected—the one meeting the geodetic network accuracy requirements with the lowest number of necessary measurements. We tested the algorithm (and individual partial algorithms) on four geodetic networks designed to resemble real-world networks with 50–500 modifications to each of those networks in individual tests. The results indicate that (i) the results achieved by the combined algorithm are close to the optimal results and (ii) none of the four partial algorithms universally performs the best, implying that the combination of the four partial algorithms is necessary for achieving the best possible results of geodetic network optimization. [ABSTRACT FROM AUTHOR]

The geodetic network, made in the classic system of measurements, has served for more than half a century to carry out topographic surveys, constituting an important cartographic and geodetic fund for engineering works and administrative records. The implementation and use of modern technologies in the determination of higher order support networks is a particularly complex process, aiming at the efficiency of topo-geodetic works by adopting an effective work method based on spatial information. It is known that in Romania geodetic works use the Stereographic Projection on a single secant plane developed in 1970 on the Krasovski ellipsoid. For leveling works, the reference plan is the level of the Black Sea, determined in 1975. The technology-method impact can be successfully applied in one of the problems to be solved, namely the one related to the determination of a support network, it has existed until now. Applying another technology, respectively working method, we have to solve the same problem, but in a shorter time and with higher quality results. All fields of activity seek the application of top technologies in the respective field, to reduce costs and the time needed to solve problems by adopting solutions that make the topo-geodetic measurement methods more efficient. [ABSTRACT FROM AUTHOR]

Underground structures in the form of tubes open at both ends, placed horizontally or vertically on a slight slope, and through which a road passes: railway, road, canal, or waterway, which connect two parts of the road separated by an obstacle, are called tunnels. During the design and construction of tunnels, geodetic works are carried out following legal regulations. Attention should be paid to the geodetic basis, as well as to the tunnel marking network to perform reconnaissance and stabilization of points in a high-quality manner. Further works include the marking of points, as well as their control, then calculations and data transformations to obtain the coordinates in the global coordinate system. This paper presents the mentioned works during the construction of the Čortanovci tunnel.

The introduction of satellite technologies for determining coordinates opens up new opportunities both for creating a geodetic basis for the development of the subsoil, and for the production of surveying and geodetic works at mines. In this regard, it seems very promising to transfer the coordinates obtained by an automated method on the surface of an ellipsoid to a horizontal local projection oriented normally to a vertical line. At the same time, it is possible to control this deviation and select a local area that meets the specified accuracy parameters. Such an approach to the creation of a geodynamic polygon (GDP) during the development of the subsoil will certainly make it possible to more accurately make design decisions in kind. The article proposes an up-to-date approach to the formation of a geodynamic polygon, which consists in the use of a local flat surface with topocentric coordinates. The GDP created in topocentric coordinates has minimal distortions relative to geocentric coordinates, in which the lion's share of geodetic work is carried out today. Calculations and concrete examples of the translation of coordinates from a geocentric system to a topocentric one (a flat projection of geocentric coordinates with topocentric coordinates) are given, in which the measurement results are equalized. It is important to note that the results are compared with respect to the Gauss-Kruger zonal coordinate system. The possibility of translating coordinates from one system to another is demonstrated in order to preserve traditional forms of material presentation and measurement evaluation. [ABSTRACT FROM AUTHOR]

The alpine environment with a high degree of nature protection is characterized by complete non-intervention. The processes and phenomena occurring in it are exclusively of a natural origin. Related geohazards are threatening the safety of people's movement. They arise as a result of a combination of meteorological, hydrological, and geological–morphological factors permanently operating in the country. Therefore, the prevention of fatal events is limited to monitoring and predicting changes in selected objects where we expect change. Changes in the shape and dimension, or the object's deformation, can be documented using geodetic and photogrammetric measurements. Our research focuses on monitoring a rock talus cone in High Tatras, Slovakia, at an altitude of 1700 m above sea level (ASL), created mainly due to erosion and seasonal torrential rains. To monitor changes in selected objects, we used mass non-contact methods of terrestrial laser scanning (TLS), UAS photogrammetry based on the principle of structure-from-motion–multi-view stereo (SfM–MVS), and airborne laser scanning (ALS). From the selective measurement methods, spatial measurement by a total station (TS) and height measurement based on the principle of precise leveling were used in the monitoring deformation network on a stand-alone boulder. The research results so far analyze and evaluate the possibilities, limits, effectiveness, and accuracy of the measurement and data processing methods used. As a result, we propose a complex methodology for monitoring similar phenomena in alpine environments. [ABSTRACT FROM AUTHOR]

Dams play a pivotal role in providing essential services such as energy generation, water supply, and flood control. However, their stability is crucial, and continuous monitoring is vital to mitigate potential risks. The Mosul Dam is one of the most interesting infrastructures in Iraq because it was constructed on alternating beds of karstified and gypsum which required continuous grouting due to water seepage. Therefore, the ongoing maintenance issues raised international concerns about its stability. For several years the dam indicated a potential for disastrous failure that could cause massive flooding downstream and pose a serious threat to millions of people. This research focuses on comprehensive statistical assessments of the dam geodetic network points across multiple epochs of long duration. Through the systematic application of three statistical tests and the predictive capabilities of the Kalman filter, safety and long-term stability are aimed to be enhanced. The analysis of the dam’s geodetic network points shows a consistent trend of upstream-to-downstream movement. The Kalman filter demonstrates promising outcomes for displacement prediction compared to least squares adjustment. This research provides valuable insights into dam stability assessment, aligns with established procedures, and contributes to the resilience and safety of critical infrastructure. The outcome of this paper can encourage future studies to build upon the foundation presented.

Monitoring displacements of the object can be performed using geodetic methods by selecting reference points on the surrounding terrain and points on the object that discretely describe the object's behavior. The measurements are repeated in several epochs. By analyzing the geodetic network we can determine the status of a single point, i.e., whether the point has moved or not. The article discusses the testing of congruence, the testing of transformation of a single triangle, and the calculation of other deformation parameters in 2D networks resulting from the changes of points coordinates between two epochs. This is essentially the content of the Munich deformation method presented by W.M. Welsch, which includes the X- and L-method. The article also proposes some corrections to the original Munich approach. Finally, the applicability of the method is shown on a well-known practical example. [ABSTRACT FROM AUTHOR]

The optimization of measurements in a geodetic network (second-order design) has been investigated in the past; however, the practical usability of the outcomes of most of such studies is doubtful. Hence, we have proposed a new automated optimization algorithm, taking into account the practical aspects of total station measurements. The algorithm consists of four parallel partial algorithms, of which one is subsequently automatically selected—the one meeting the geodetic network accuracy requirements with the lowest number of necessary measurements. We tested the algorithm (and individual partial algorithms) on four geodetic networks designed to resemble real-world networks with 50–500 modifications to each of those networks in individual tests. The results indicate that (i) the results achieved by the combined algorithm are close to the optimal results and (ii) none of the four partial algorithms universally performs the best, implying that the combination of the four partial algorithms is necessary for achieving the best possible results of geodetic network optimization.

This study investigates panorama photogrammetry (PPh) as a potential method to collect massive 3D information for long-range deformation monitoring. Particularly, this study focuses on areas with measuring restrictions, i.e., inaccessible objects and distances above 0.6 km. Under these particular conditions, geodetic techniques based on Electromagnetic Distance Meters (EDMs) or Total Stations (TSs) can provide coordinates with a precision better than 1 cm, but only for a limited number of discrete points. For mass capture, Terrestrial Laser Scanning (TLS) is normally the preferred solution, but long-range instruments are expensive, and drawbacks such as weak return signals and non-automatic target recognition appear. As an alternative, PPh is investigated in the well-controlled area of La Muela in Cortes de Pallas, where images are automatically captured from geodetic pillars using a GigaPan device, processed, and then rigorously compared to TLS point clouds. The results obtained after integrating both techniques into a high-accuracy geodetic reference frame show that PPh and TLS provide similar precision to within approximately 4 cm in the range of 0.6–1.0 km. Therefore, considering cost-effectiveness and ease of use, the proposed method can be considered a low-cost alternative to TLS for long-range deformation monitoring.

The geodetic points that form the national geodetic network cover large areas, and the accuracy of their determination is a function of the distances between them. In mining areas, a local geodetic network superior in precision to the national geodetic network is required. However, it is necessary to include the geodetic points that form the local network in the national geodetic network. The present work represents the methodology for solving the mentioned purpose. [ABSTRACT FROM AUTHOR]

The total station is the most basic geodetic measuring instrument, locally the most accurate and versatile. Its accuracy is the cornerstone of its use and is defined by the standard deviations of horizontal direction, zenith angle and slope distance measurements. These accuracy parameters are given by the manufacturer, but these are only valid under optimum measurement conditions. To ensure the credibility and reliability of the measurements, these values must be periodically ascertained or determined for atypical measurement configurations or measurement conditions. Standardised procedures are used for this purpose, but in our opinion, they do not reflect the full influence of the measuring conditions and other measuring aids. A comprehensive determination of the accuracies (variation components) from the alignment, where all possible influences in a given situation are applied, may be considered the most appropriate for determining the angular accuracy of measurements. Such atypical conditions are certainly represented by geodetic measurements in the confined spaces of an underground mine. Thus, an experimental determination of the accuracy of four different robotic total stations was carried out at the Center of experimental geotechnics in a mine Josef teaching centre (CTU in Prague), and the Frstner method was used to determine the variation components. A network of 6 stations and 8 target points was designed. The grid size was approximately 32x21 m with 4 - 31 m lengths. A network with the same configuration was also duplicated at the surface to assess whether the accuracy is different in underground and how the results will correspond to the accuracy claimed by the manufacturers. The result of the testing is that the accuracy claimed by the manufacturers is maintained even under such difficult measurement conditions in narrow corridors and with short sights. The overall evaluation also found that the accuracy achieved underground and on the surface is identical, although it varies from instrument to instrument. [ABSTRACT FROM AUTHOR]

This article describes the geodetic network of the Urbas landslide. It is the largest landslide in the Koroška Bela region, which, if triggered, can endanger human lives and damage infrastructure. In order to monitor the landslide, a geodetic network was established in the area of the Urbas landslide, on the basis of which the movements of control points can be calculated. After various analyses, only two small areas near the Urbas landslide proved to be stable, so we established four reference points there. In this research we defined the geodetic datum of the geodetic network of the Urbas landslide. The geodetic datum was defined on the basis of four measurement epochs processed with our own software.

A high-precision geodetic reference frame was required in Cortes de Pallás (Spain) to undertake a long-term deformation monitoring project. Involving distances up to 2000 m, the aimed accuracy was 1 mm and 3 mm for horizontal and vertical components, respectively. Such a high precision is necessary to detect possible displacements of selected points on a critical rocky area in a short period of time, i.e., 2 or 3 years, and also to provide ground control for the integration of precise 3D models periodically obtained by remote sensing techniques. Considering the historical geotechnical problems of the area, the possible influence of the hydroelectric power plant, and the peculiar orography of the zone, a proper analysis of the stability is crucial if the reference frame is to be used for rigorous over-time deformation monitoring. This paper describes the deformation monitoring of a 10-pillar geodetic network which was measured from 2018 to 2020 by using a sub-millimetric Mekometer ME5000 (0.2 mm + 0.2 ppm) along with a demanding observing methodology which includes a network of data loggers for temperature, humidity, and air pressure as well as proper calibration of sensors and instruments to prevent potential inconsistencies between the scale of the network and the unit of length of the International System (SI meter). The results demonstrated that the chosen methodology yielded the aimed accuracy. However, using such a high precision methodology entails the problem that small displacements of only 1 or 2 mm are significantly detected as deformations by conventional deformation analysis and then it arises the problem of finding a subset of stable points for a rigorous datum realization when all the points seem to displace. This general problem is analyzed in the particular case of Cortes de Pallás, where a balanced mix of deformation analysis and technical decisions was eventually adopted to define a precise and stable reference frame for rigorous over-time deformation monitoring. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate millimeter-scale deformations in Tallinn, the capital of Estonia, by using repeated leveling data and the synthetic aperture radar (SAR) images of Sentinel-1 satellite mission. The persistent scattered interferometric SAR (PS-InSAR) analysis of images from ascending and descending orbits from June 2016 to November 2021 resulted the line-of-sight (LOS) displacement velocities in the Tallinn city center. Velocity solutions were estimated for the full period of time, but also for shorter periods to monitor deformation changes in yearly basis. The gridded LOS velocity models were used for the decomposition of east-west and vertical velocities. Additionally, the uncertainty of 2D velocity solutions was estimated by following the propagation of uncertainty. The 3D velocity of permanent GNSS station “MUS2” in Tallinn was used to unify the reference of all PS-InSAR velocity solutions. The results of the latest leveling in Tallinn city center in 2007/2008 and 2019 showed rather small subsidence rates which were in agreement with InSAR long-termsolution. However, the short-termInSAR velocity solutions revealed larger subsidence of city center with a rate about –10 mm/yr in 2016–2017, and the uplift around 5 mm/yr in 2018–2019 with relatively stable periods in 2017–2018 and 2019–2021. The inclusion of groundwater level observation data and the geological mapping information into the analysis revealed possible spatiotemporal correlation between the InSAR results and the groundwater level variations over the deep valleys buried under quaternary sediments.

In classical two-dimensional (2D) geodetic networks, reducing slope distances to horizontal ones is an important task for engineers. These horizontal distances along with horizontal directions are used in 2D geodetic adjustment. The common practice for this reduction is the use of vertical angles to reduce distances using trigonometric rules. However, one faces systematic effects when using vertical angles. These effects are mainly due to refraction, deflection of the vertical (DOV), and the geometric effect of the reference surface (sphere or ellipsoid). To mitigate refraction and DOV effects, one can choose to observe the vertical angles reciprocally if the baseline points' elevation difference is small. This paper quantifies these effects and proposes a proper solution to eliminate the effects in small-scale geodetic networks (where the longest distances are less than 5 km). The goal is to calculate slope distances into horizontal ones appropriately. For this purpose, we used the SWEN17_RH2000 quasigeoid model (in Sweden) to study the impact of the DOV applying different baseline lengths, azimuths, and vertical angles. Finally, we propose an approach to study the impact of the geometric effect on vertical angles. We illustrate that the DOV and the geometric effects on vertical angles measured reciprocally are significant if the height difference of the start point and endpoint in the baseline is large. Geometric correction should be considered for the measured vertical angles to calculate horizontal distances correctly if the network points are not on the same elevation, even if the vertical angles are measured reciprocally. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate millimeter-scale deformations in Tallinn, the capital of Estonia, by using repeated leveling data and the synthetic aperture radar (SAR) images of Sentinel-1 satellite mission. The persistent scattered interferometric SAR (PS-InSAR) analysis of images from ascending and descending orbits from June 2016 to November 2021 resulted the line-of-sight (LOS) displacement velocities in the Tallinn city center. Velocity solutions were estimated for the full period of time, but also for shorter periods to monitor deformation changes in yearly basis. The gridded LOS velocity models were used for the decomposition of east-west and vertical velocities. Additionally, the uncertainty of 2D velocity solutions was estimated by following the propagation of uncertainty. The 3D velocity of permanent GNSS station "MUS2" in Tallinn was used to unify the reference of all PS-InSAR velocity solutions. The results of the latest leveling in Tallinn city center in 2007/2008 and 2019 showed rather small subsidence rates which were in agreement with InSAR long-termsolution. However, the short-termInSAR velocity solutions revealed larger subsidence of city center with a rate about -10 mm/yr in 2016-2017, and the uplift around 5 mm/yr in 2018-2019 with relatively stable periods in 2017-2018 and 2019-2021. The inclusion of groundwater level observation data and the geological mapping information into the analysis revealed possible spatiotemporal correlation between the InSAR results and the groundwater level variations over the deep valleys buried under quaternary sediments. [ABSTRACT FROM AUTHOR]

The purpose of the article is to present a combined approach that connects several methods and algorithms to increase the effectiveness of the geodetic network measurement structure for determining horizontal and vertical displacements of engineering objects. Determining the deformation of commercial objects and objects of practical value allows to assess their technical condition. In case of critical changes at such objects, appropriate planning of protection, reconstruction and modernization works is also provided and the negative impact of the environment and weather conditions is indicated. Regardless of the methods used, the measurement of movements and deformations of structures is always preceded by an analysis of the prevailing conditions, as well as a network of geodetic measurement determination and control. These analyses are carried out taking into account manufacturability, economy, safe use of objects, human safety and environmental protection. The target function was defined, which in this case was chosen as the entropy of the geodesic observation network through the measurement of the parameters vector with true values. Analysing the structure of the control and measurement network and improving its efficiency by the number of necessary observations becomes important for determining reliable changes occurring at the object and the ability to conduct the necessary measurements in the shortest possible time. At the same time, the improved network structure should ensure the redundancy of observations made to match the geodetic network with the modified methods. The optimal number of observations in the geodetic network depended on the observation structure informativeness. During the research, it was noticed that the use of a combined approach will allow selecting only those observations that are the most informative. This will reduce the measurement time without reducing the accuracy of the received movements. The obtained results of the numerical analysis showed the performance of the offered solution for increasing the efficiency of the geodetic network structure formation. It also allows faster and more economical performance of engineering structures geodetic measurements. [ABSTRACT FROM AUTHOR]

The paper presents a series of results regarding the application of GNSS technology for measuring displacements to earth dams. An appropriate horizontal and vertical deformation-tracking network must be established for the rapid monitoring of earthmoving movements. Data obtained from the monitoring network can be used in the earth dam stability analysis program. Periodic tracking of earth dams using GNSS technology provides high accuracy of spatial distortions. The results of the paper show the application of GNSS technology to monitor the deformations of the Podisu earth dam located on the Sheep Valley River in Iasi County. In the first stage of research (2019 and 2020), the local geodetic tracking network was created. To monitor the dam, four control landmarks were placed on the crest of dam and seven landmarks on the downstream slope. In the second stage of the research (year 2021) the measurements of the displacements at the earth dam were performed. The GNSS monitoring method has the advantage of positioning the target quickly, statically, and with high accuracy. The measurements used fixed stations located at two points in the local geodetic network. Four Trimble GNSS receivers were used for the measurements. The resulting data was processed using the Trimble Business Centre program. The obtained results were analysed in comparison with those existing in the design documentation and technical expertise of the dam. The results highlight the presence of displacements on the crest of a dam and slopes of the dam. The final findings highlight the performance of GNSS technology in the monitoring process, where it provides millimetre-accurate accuracy with high spatial and temporal accuracy.

Monitoring displacements of the object can be performed using geodetic methods by selecting reference points on the surrounding terrain and points on the object that discretely describe the object’s behavior. The measurements are repeated in several epochs. By analyzing the geodetic network we can determine the status of a single point, i.e., whether the point has moved or not. The article discusses the testing of congruence, the testing of transformation of a single triangle, and the calculation of other deformation parameters in 2D networks resulting from the changes of points coordinates between two epochs. This is essentially the content of the Munich deformation method presented by W.M. Welsch, which includes the X- and L-method. The article also proposes some corrections to the original Munich approach. Finally, the applicability of the method is shown on a well-known practical example.

This article describes the geodetic network of the Urbas landslide. It is the largest landslide in the Koroika Bela region, which, if triggered, can endanger human lives and damage infrastructure. In order to monitor the landslide, a geodetic network was established in the area of the Urbas landslide, on the basis of which the movements of control points can be calculated. After various analyses, only two small areas near the Urbas landslide proved to be stable, so we established four reference points there. In this research we defined the geodetic datum of the geodetic network of the Urbas landslide. The geodetic datum was defined on the basis of four measurement epochs processed with our own software. [ABSTRACT FROM AUTHOR]

In adjusted geodetic networks, cases of local configuration defects (defects in the geometric structure of the network due to missing data or errors in point numbering) can be encountered, which lead to the singularity of the normal equation system in the least-squares procedure. Numbering errors in observation sets cause the computer program to define the network geometry incorrectly. Another cause of a defect may be accidental omission of certain data records, causing local indeterminacy or lowering of local reliability rates in a network. Obviously, the problem of a configuration defect may be easily detectable in networks with a small number of points. However, it becomes a real problem in large networks, where manual checking of all data becomes a very expensive task. The paper presents a new strategy for the detection of configuration defects with the use of the Tikhonov regularization method. The method was implemented in 1992 in the GEONET system (www.geonet.net.pl).

In the past, church belfries, due to their shape and higher layout, often served as reference points in surveying. With the development of satellite based positioning methods and the establishment of the D96/TM coordinate system, they slowly lost their significance. Nevertheless, unlike ground trigonometric points, they have remained largely intact. As such, they enable the determination of transformation parameters between the old and the new coordinate systems. Therefore, we need to determine their positions in the new coordinate system. In this paper, we describe the process of determining the position of church belfries using terrestrial laser scanning (TLS) in the case of both belfries of the Trnovo church. The process involves determining coordinates of the tie points for georeferencing the point clouds, which requires the determination of the geodetic datum by a combination of GNSS measurement and geometric levelling, and the classical geodetic survey of the geodetic network with free-network adjustment and further use of the S-transformation. Based on the georeferenced point clouds, we determined the position of the trigonometric point by sphere parameters adjustment. The data is filtered using the RANSAC so that we only have points that belong to the sphere in the adjustment process. The results were compared with the positions determined based on the classical terrestrial geodetic survey.

In this paper, the theoretical background of the Caspary method of geodetic deformation analysis is described and implemented in a simulated geodetic network in which two epochs of measurements are used. The Caspary approach foresees congruence testing of the geodetic network, the determination of the stable points between two analysed epochs, the transformation of the geodetic network using S-transformation, the calculation of displacements, and, in the last step, the graphical presentation of displacement vectors. Results obtained from the presented example are similar to those presented in the Hannover, Karlsruhe, Delft, Fredericton, München, and robust methods.

The work presents the method of tying the points of the geodetic network to the wall signs with an inverted angular serif. The calculation of point coordinates is shown on an example. [ABSTRACT FROM AUTHOR]

Purpose. Developing the methods for forecasting changes in the geological environment based on integrated monitoring, which ensures industrial and environmental safety of Central Kazakhstan region. Methodology. Integrated approach was used in the work, including: study on mining and geological conditions, structural features of rocks and conducting mine surveying at mines on the basis of modern methods and means of geomonitoring developed by the authors. Findings. Methodology for integrated geodynamic monitoring system is developed. A new method of geodynamic polygon establishment is proposed. Study results were implemented at operating mining enterprises during implementation of projects “Comprehensive monitoring of slow deformation processes of the earth’s surface during large-scale development of ore deposits in Central Kazakhstan” and “Development of innovative methods for forecasting and assessing the state of rock mass to prevent technogenic emergencies”, and the results were used in the educational process of Satbayev University. Originality. As a result of the research work carried out, the following were created and introduced into production: - geodynamic polygon (GDP) of the area, established on the basis of the “nodal” method, combined with leveling, satellite and seismological points, allowing monitoring coverage of exploration and mining operations, as well as increasing efficiency of observations and reducing capital costs for mineral production; - developed constructions of permanent (ground and underground) forced centering points (FCP), which allow increasing productivity and observations accuracy; - method for photographing structural features of rock mass using a 3D laser scanner, which makes it possible to study elements of cracks occurrence and faults in rocks in sufficient detail; - composition of strengthening solution from mining waste to increase stability of disturbed sections of open cast benches was developed. The novelty of the developed methods and means is confirmed by RK patents for invention. Practical value. Obtained results can be used to improve the level of industrial safety at mines and minimize environmental risks caused by subsoil development. [ABSTRACT FROM AUTHOR]

In this paper is depicted the creation of the geodetic network of Vinga commune. Vinga is a commune in Arad County, close to the boundary with TIMIŞ County. The commune also includes the settlements of Mănăștur and Mailat, with a total area of around 14142 ha. The following criteria were considered before selecting the points that will thicken the national network and be determined by GNSS measurements: to ensure the point's preservation for a long time, to be visible from 15 degrees above the horizon, to have GNSS receivers set to collect data every 5 seconds, and to be accessible regardless of the weather conditions. There should be no high-power electrical installations near the stations or emission relays, according to the fundamental criteria that are decided to be able to be employed in future operations. The measurements were totally carried out using satellite technology. The following activities were carried out in order to create this geodetic network: GNSS measurements using the static technique for thickening the support network, and GNSS measurements using the radio method for thickening the support network. Feno terminals were used to make field markings for the GNSS approach of thickening the network. With reference to the locations in the national geodetic network RO, two L1 / L2 dual frequency receivers, model LEICA VIVA GS08, were utilized for measurement. The geodetic thickening network is being built to meet some economic and legal administrative criteria, and it will serve as the foundation for topographic measurements for various reasons. [ABSTRACT FROM AUTHOR]

The paper presents a series of results regarding the application of GNSS technology for measuring displacements to earth dams. An appropriate horizontal and vertical deformation-tracking network must be established for the rapid monitoring of earthmoving movements. Data obtained from the monitoring network can be used in the earth dam stability analysis program. Periodic tracking of earth dams using GNSS technology provides high accuracy of spatial distortions. The results of the paper show the application of GNSS technology to monitor the deformations of the Podisu earth dam located on the Sheep Valley River in Iasi County. In the first stage of research (2019 and 2020), the local geodetic tracking network was created. To monitor the dam, four control landmarks were placed on the crest of dam and seven landmarks on the downstream slope. In the second stage of the research (year 2021) the measurements of the displacements at the earth dam were performed. The GNSS monitoring method has the advantage of positioning the target quickly, statically, and with high accuracy. The measurements used fixed stations located at two points in the local geodetic network. Four Trimble GNSS receivers were used for the measurements. The resulting data was processed using the Trimble Business Centre program. The obtained results were analysed in comparison with those existing in the design documentation and technical expertise of the dam. The results highlight the presence of displacements on the crest of a dam and slopes of the dam. The final findings highlight the performance of GNSS technology in the monitoring process, where it provides millimetre-accurate accuracy with high spatial and temporal accuracy. [ABSTRACT FROM AUTHOR]

The use of robots is widespread in the field of construction nowadays. Robots may be mobile or static depending on the specific task or application. One of the major challenges when implementing mobile robots is localisation. In the field of robotics, localisation is often performed in a relative sense, however some applications require absolute localisation. In order to provide absolute positions, appropriate sensors such as Global Navigation Satellite Systems (GNSS) or total stations can be employed. The underlying task is embedded within the Germany´s Excellence Strategy "Integrative Computational Design and Construction for Architecture (IntCDC)" funded by the German Research Foundation (DFG). The specific sub-project deals with issues of robot-robot collaboration and specifically aims the provision of absolute position and orientation, designated as pose, of a mobile construction robot. The determined pose information supports different control loops of the robot including automated driving, steering and tool operations. The choice of the sensor system favoured a robotic total station (RTS), because of its real-time capability and measurement accuracy. The measurement system is coupled with an Inertial Measurement Unit (IMU) for orientation. To counteract line-of-sight interference between the RTS and the target, the contribution proposes the use of a network of four spatially evenly distributed RTSs. The quality characteristics of different pose determination procedures of a mobile construction robot are investigated using methods from the geodetic network theory. Conclusions about accuracy and reliability distribution across the construction site are presented numerically and graphically. [ABSTRACT FROM AUTHOR]

Today with the fast and powerful computers, large data storage systems and modern softwares, the probabilities distribution and efficiency of statistical testing algorithms can be estimated using computerized simulation. Here, we use Monte Carlo simulation (MCS) to investigate the power of the test and error probabilities of the Baarda’s iterative data snooping procedure as test statistic for outlier identification in the Gauss-Markov model. The MCS discards the use of the observation vector of Gauss-Markov model. In fact, to perform the analysis, the only needs are the Jacobian matrix; the uncertainty of the observations; and the magnitude intervals of the outliers. The random errors (or residuals) are generated artificially from the normal statistical distribution, while the size of outliers is randomly selected using standard uniform distribution. Results for simulated closed leveling network reveal that data snooping can locate an outlier in the order of magnitude 5σ with high success rate. The lower the magnitude of the outliers, the lower is the efficiency of data snooping in the simulated network. In general, considering the network simulated, the data snooping procedure was more efficient for α=0.01 (1%) with 82.8% success rate.

New technical developments, growing applications and requests for higher accuracy in georeferencing of national reference frame raise a demand on high accuracy National Terrestrial Reference Frame based on Global Navigation Satellite System (GNSS) and other space geodetic techniques. Since the last decades many countries decided to switch main geodetic control points from triangulation points to Continuously Operating Reference Stations (CORS). This task is currently undertaken by the geodetic authority of Mongolia in collaboration with research and private organizations. The first continuous Global Positioning System (GPS) station in Mongolia became operational in the late 1995 for the global geodetic scientific applications. Since 1997 the survey-mode GPS observations were utilized in Mongolia for crustal deformation studies and for re-survey of the national triangulation network. During the years 2011-2013 CORS network of nearly 18 stations has been built to modernize the old geodetic network. Currently the total number of the reference stations counts to nearly 40. Since Mongolia is located in the tectonically active region, its geodetic reference frame is continuously deforming, which requires regular updates of reference frame. In this paper we discuss the technical issues of the national reference frame of Mongolia considering the crustal deformation of Mongolia and the data management of the national CORS network. Үндэсний геодезийн сүлжээг GNSS CORS тулгуур тогтолцоогоор шинэчлэх асуудалд Хураангуй: Техникийн шинэчлэл болон өндөр нарийвчлалтай газарзүйн холболт хийх хэрэгцээ, шаардлагын өсөлт нь Глобаль Навигацийн Дагуулын Систем болон бусад сансрын геодезийн техникт суурилсан илүү өндөр нарийвчлалтай Үндэсний Тулгуур Тогтолцоог шаардах боллоо. Сүүлийн арваад жилд олон улс орон геодезийн хяналтын цэгүүдээ триангуляцийн цэгээс байнгын ажиллагаатай тулгуур станцаар орлуулах үйл ажиллагаа явуулж эхэлсэн бөгөөд хөгжингүй орнууд динамик тогтолцоо руу шилжиж байна. Энэ ажлыг Монгол улсад Газрын Харилцаа Геодези Зурагзүйн Газар толгойлон судалгааны болон хувийн хэвшлийн байгууллагуудтай хамтран хэрэгжүүлж байгаа билээ. Байнгын ажиллагаатай GPS станц Монголд анх 1995 оны сүүлээс ажиллаж эхэлсэн бөгөөд геодезийн шинжлэх ухааны глобаль хэрэглээнд зориулагдаж байв. 1997 оноос эхлэн давтан хэмжилтийн GPS ажиглалтуудыг царцдасын деформац болон триангуляцийн сүлжээг хэмжихэд ашиглаж эхлэв. 2011-2013 оны хооронд триангуляцийн сүлжээг шинэчлэх зориулалтаар ~18 байнгын ажиллагаатай тулгуур станцуудын сүлжээ байгуулагдсан бөгөөд эдгээр станцуудын тоо одоо 40 гарсан байна. Монгол улсын нутаг дэвсгэр нь тектоникийн идэвхтэй бүс нутагт оршдог тул геодезийн тулгуур тогтолцоо нь байнгын деформацд байна. Тиймээс тулгуур тогтолцоог тогтмол шинэчилж байх шаардлагатай. Энэ өгүүлэлд бид үндэсний тулгуур тогтолцооны техник нөхцлийг байнгын ажиллагаатай станцуудын ажиллагаа, Монгол орны царцдасын деформацыг тооцон тусгасан бөгөөд үндэсний CORS (Байнгын Ажиллагаатай Тулгуур Станцын) сүлжээний өгөгдөл, түүний зохицуулалтын талаар илтгэх болно. Түлхүүр үг: GPS геодези, царцдасын деформацын мониторинг, геодезийн сүлжээ

A Geodetic Network is a network of point interconnected by direction and/or distance measurements or by using Global Navigation Satellite System receivers. Such networks are essential for the most geodetic engineering projects, such as monitoring the position and deformation of man-made structures (bridges, dams, power plants, tunnels, ports, etc.), to monitor the crustal deformation of the Earth, to implement an urban and rural cadastre, and others. One of the most important criteria that a geodetic network must meet is reliability. In this context, the reliability concerns the network's ability to detect and identify outliers. Here, we apply the Monte Carlo Method (MMC) to investigate the reliability of a geodetic network. The key of the MMC is the random number generator. Results for simulated closed levelling network reveal that identifying an outlier is more difficult than detecting it. In general, considering the simulated network, the relationship between the outlier detection and identification depends on the level of significance of the outlier statistical test.

Geodetic and topographic works determine the necessary information base and of major importance in the design and management of underground construction works (mining, hydrotechnics, roads, etc.). The efficiency and safety of these investments with special financial implications depend on their quality. In this context, the geodetic orientation of the underground topographic works was the main and permanent subject of study and analysis on which this scientific paper refers. [ABSTRACT FROM AUTHOR]

Several least-squares adjustment techniques were tested for dam deformation analysis. Deformation monitoring had only been studied horizontally. Simulated observations were first performed to compare the three methods of least-squares: observations with their initial weight, observations with the estimated variance component, and the regularization method. The best scenario was adopted for the real network. The results demonstrated that a more accurate outcome is possible by least-square variance component estimation (LS-VCE). Comparison of the estimated and simulated displacements in the LS-VCE method indicated that the difference for the two east–west and north–south components is 0.05 and 0.08 mm, while this difference in the other two modes is 1.02 and 0.67 mm for observations with their initial weight, and 0.64 and 0.16 mm for the Tikhonov regularization method, respectively. In the best method, an improvement was found in the standard deviation of the east–west, south–north components, the estimation of the major axis of the error ellipse, and the trace of the variance–covariance matrix of unknowns, in comparison with the other methods. [ABSTRACT FROM AUTHOR]

Surveying is an undisputed link in the chain of professions that participate in the realization of projects for the construction of various buildings and structures. Different stages of construction require the engagement of geodesists in a different range. The process of construction of the pillar of the viaduct "Briješće" required the collaboration of a large number of experts of various profiles, among which is a geodetic expert. The paper contains a detailed description of geodetic works in the construction of the viaduct pillar, starting from the establishment of the control network to the final control of the pillar construction.

In the old coordinate system, church belfries often served as reference points in detail surveying. Consequently, their coordinates were regularly maintained in the geodetic databases of the old coordinate system. Their usability was significantly reduced by the establishment of the new coordinate system along with the use of satellite-based positioning methods and transformation models. Considering that the number of ground points of the old trigonometric geodetic networks decreases due to reconstruction, today they have gained practical value. Most of them were preserved in their original condition, which enables a continuous transition from the old to the new coordinate system as well as the reconstruction of the old situation on the basis of the old coordinate system data. They can be used in the determination of the transformation parameters of the detail or for the quality evaluation of the state transformation model. For this, their coordinates should be determined in the new coordinate system. The present article describes the determination of positions of five church belfries in the new coordinate system D96/TM, which are located in the southwestern part of Ljubljana. The procedure combines the determination of the geodetic network datum by GNSS, the inclusion of terrestrial measurements and free-network least squares adjustment and further use of the S-transformation. Further comparison of coordinates, acquired in different ways, shows some centimetre differences in each coordinate component for the given sample of church belfries. Therefore, for the sample under consideration, we can conclude that the Slovenian triangle-based transformation model effectively describes the transformation between the old and the new coordinate systems in the area under consideration.

In the paper the efficacy of two different approaches for outlier detection in geodetic networks is analysed on a test example of a control network for geodetic monitoring of the Pobednik statue in the Kalemegdan Fortress in Belgrade by applying the mean success rate (MSR). Conventional tests and robust methods were applied for detecting outliers. The experimental results indicate that the new approach based on original observations provides higher efficiency of the applied methods than the classical approach for outlier detection in geodetic networks.

Energy remediation or renovation of buildings is an engineering project that provides saving of at least half the energy used for heating and cooling. The article presents the possibilities of cooperation of the geodetic profession in the energy remediation of complex buildings that require the construction of building plans based on 3D-graphic models of objects. The combination of classical terrestrial measurement of facade and terrestrial laser scanner is presented on a case of multi-apartment building, with the aim of energy remediation using prefabricated facade elements. Considering the required high precision, adequate geodetic network needs to be established and high resolution of detail scanning must be provided. The measurement and processing of the reference object show that geodesy with advanced measurement technologies can provide support to other professions and thus significantly influence the efficiency and cost-effectiveness of energy remediation.

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In the past, church belfries, due to their shape and higher layout, often served as reference points in surveying. With the development of satellite based positioning methods and the establishment of the D96/TM coordinate system, they slowly lost their significance. Nevertheless, unlike ground trigonometric points, they have remained largely intact. As such, they enable the determination of transformation parameters between the old and the new coordinate systems. Therefore, we need to determine their positions in the new coordinate system. In this paper, we describe the process of determining the position of church belfries using terrestrial laser scanning (TLS) in the case of both belfries of the Trnovo church. The process involves determining coordinates of the tie points for georeferencing the point clouds, which requires the determination of the geodetic datum by a combination of GNSS measurement and geometric levelling, and the classical geodetic survey of the geodetic network with free-network adjustment and further use of the S-transformation. Based on the georeferenced point clouds, we determined the position of the trigonometric point by sphere parameters adjustment. The data is filtered using the RANSAC so that we only have points that belong to the sphere in the adjustment process. The results were compared with the positions determined based on the classical terrestrial geodetic survey. [ABSTRACT FROM AUTHOR]

Copyright of Boletin de Geologia is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study presents a geodetic deformation monitoring approach and its application on two severely affected and uninvestigated study sites in India, namely the Bhurkunda coal mines in Jharkhand, and the Sirobagarh landslide in Rudraprayag, Uttarakhand. For the Bhurkunda site (characterized by underground coal mining related subsidence), a network of 56 GNSS points, densified by Total Station (TS) ground points, was set up during three field visits. GNSS derived deformation estimates reveal that the southern part of the investigated area underwent subsidence (maximum displacement 1.813 m). Furthermore, DEM differences of the three epochs generated using TS points detect a subsidence of 1.358±0.057 m with similar pattern and magnitude of movement as detected by GNSS stations. For the Sirobagarh landslide (witnessing recurring slides due to local geological conditions and rainfall), a GNSS network of six control points in an area of 500×600 m2 was established. Deformation estimates from GNSS show subsidence in the area with a horizontal trend of movement towards the Alaknanda river situated below the landslide (maximum horizontal and vertical displacement values are 0.1306 m and 2.1315 m respectively). Further, for the Sirobagarh landslide, multi-temporal interferometry using Sentinel-1 SAR images detect displacement vectors showing downward movement of the landslide, with displacement rates ranging from 0.008 to −0.115 m yr−1. It is evident that the landslide scarp encountered high magnitude subsidence, whereas the area containing and surrounding the landslide (~30 km2) underwent a moderate rate of subsidence. A set of surveying guidelines for monitoring deformation events of similar kind are discussed. [ABSTRACT FROM AUTHOR]

A set of stable and identifiable points--known as control points--are interconnected by direction, distance or height differences measurements form a geodetic network. Geodetic networks are used in various branches of modern science, such as monitoring the man-made structures, analysing the crustal deformation of the Earth, establishing and maintaining a geospatial reference frame, mapping, civil engineering projects and others. One of the most crucial components for ensuring the network quality is Geodetic Network Design. The design of a geodetic network depends on its purpose. In this paper, an automatic procedure for selection of control points is proposed. The goal is to find the optimum control points location so that the maximum influence of an anomaly measurement (outlier) on the coordinates of the network is minimum. Here, the concept of Minimal Detectable Bias defines the size of the outlier and its propagation on the network coordinates is used to describe the external reliability. The proposed procedure was applied to design a levelling network. Two scenarios were investigated: design of a network with one control point (minimally constrained levelling network) and another with two control points (over-constrained levelling network). The centre of the network was the optimum position to set the control point. Results for that network reveal that the centre of the network was the optimum position to set the control point for the minimal constraint case, whereas the over-constraint case were those with less line connections. We highlight that the procedure is a generally applicable method. [ABSTRACT FROM AUTHOR]

In this paper, the theoretical background of the Caspary method of geodetic deformation analysis is described and implemented in a simulated geodetic network in which two epochs of measurements are used. The Caspary approach foresees congruence testing of the geodetic network, the determination of the stable points between two analysed epochs, the transformation of the geodetic network using S-transformation, the calculation of displacements, and, in the last step, the graphical presentation of displacement vectors. Results obtained from the presented example are similar to those presented in the Hannover, Karlsruhe, Delft, Fredericton, München, and robust methods. [ABSTRACT FROM AUTHOR]