Geodetic Control Research Articles

GEODETIC CONTROL OF THE GEOMETRY OF THE BRIDGE IN KULA USING TERRESTRIAL LASER SCANNING TECHNOLOGY

<p>In this paper, the control of the geometry of a bridge located in Kula, Serbia, was performed. This bridge bridges the Danube-Tisa-Danube canal and is a part of road 108 that runs from Bačka Topola to the Croatian border. In order to perform the geodetic control of the bridge's geometry, terrestrial laser scanning of the bridge was conducted, where a point cloud was obtained as a product. The geometry control procedure involved controlling the verticality of the grooves that enabled the movement of the weights used to raise the bridge and allowed for navigation in the canal. The geometry control of the two horizontal beams of the bridge was also examined. The results that were obtained were interpreted tabularly and graphically.</p>

Application of Geoid and Mean Dynamic Topography Models as an Alternative to the Mean Sea Level Approach in Determining Vertical Datum (Case Study: Java Island and Surrounding)

Abstract Indonesia’s archipelagic territory provides constraints for determining a seamless vertical datum throughout the region. The main constraint is how to connect the vertical datum between islands separated by sea. To define the physical height system of land areas, it usually refers to the Mean Sea Level (MSL), which has different values in each area, and the ideal MSL information is not yet available throughout regions with a minimum data duration of one cycle of 18.6 years. To overcome this constraint, in this research, another alternative method is used: applying a vertical datum that refers to a physical geoid reference surface, namely Mean Dynamic Topography (MDT) using Altimetry satellite data. The study area is Java Island and its surroundings, using vertical information from Geodetic Control Point stations, which also function as Tidal stations in the Indonesian Geospatial Reference System network. The range of MDT deviation values obtained from the Satellite Altimetry with Geodetic Ground Control data is ± 2 meters, which is a good value for coastal areas facing the open sea. This shows that the application of the geoid and MDT models can be used as an alternative, seamless MSL approach in the Java Island region and its surroundings.

FEASIBILITY STUDY OF GNSS-ENABLED GCP MARKER FOR CONTROL ESTABLISHMENT FOR DRONE SURVEYING

Abstract. This study explores the potential of GNSS-enabled Ground Control Point (GCP) markers as an alternative to traditional survey-grade receivers in observing GCPs for drone surveys. This is because an average drone flight and the observation period for rapid static are both 15 minutes. A GNSS-enabled GCP is already in the market through Propeller Aeropoints but is not available in the Philippines. Previous independent studies on the accuracy of such markers are limited as it is only focused on the accuracy. There are other considerations in using this technique such as the practicality of the marker, its usability with public Continuously Operating Reference Station (CORS) networks such as PAGeNet, and whether using it in conjunction with passive monuments will significantly affect the accuracy. The researchers designed and assembled a low-cost alternative using a u-blox module to determine the markers’ applicability and effectiveness. This study was limited to using three (3) GCPs to simulate the minimum number required to georeference in 2D. Accuracy remains an important criterion so observations will be compared with known positions. Three drone surveys were conducted to further evaluate its performance. The marker achieved 3rd Order geodetic control and demonstrated up to one standard deviation of error using statistical analysis. However, the lack of control points affected the accuracy observed in the checkpoints. This study focused on low-cost GNSS-enabled GCP marker since the commercial Aeropoints markers are not vailable in the country. Implementing this methodology in drone surveying could potentially increase survey efficiency in the Philippines and aid in the country's cadastral mapping efforts.

Топар МАЭС бөгетінің жай-күйін бағалау кезіндегі ғылыми зерттеулердің нәтижелері

The article considers the development of a methodology for conducting research on the stability of bulk structures. Software complexes have been implemented based on the use of the latest achievements in the field of geodetic instrumentation and new technologies in geophysics, hydrogeology and soil geomechanics research. The purpose of the work is to study the design features of bulk structures, the stages of their construction during the construction of roads, railways. As well as a variety of enclosing dams of tailings dumps, ash dumps of HRPP, determination of their category of responsibility, requirements during operation and timely selection of the method of geodetic control. Scientific research was carried out on hydrotechnical bulk structures of the Topar HRPP. The analysis of the current regulatory documents in Kazakhstan is carried out. The analytical review of scientific works of famous scientists of Kazakhstan, Russia and far abroad is carried out.

Assessment of Passive Geodetic Control Network in Anambra State, Nigeria

Anambra State is facing a number of environmental challenges that require geodetic infrastructure for effective solutions. Unfortunately, much remains to be done in this area as many control stations have been removed from their original locations, leaving some of their pillars in disrepair. To address this issue, a study was conducted to assess the reliability of the geodetic control network in Anambra for various applications. The study involved identifying the location of control stations within the state, assessing the status of the geodetic control network, and confirming the status of individual control stations. Using a handheld GNSS receiver, the control stations were located and critically assessed for their physical condition. In addition, in situ checks were carried out to determine if they were still maintaining their original positions. The results of the study showed that 36% of the visited and located control stations are still intact in their original positions, while 56% have been removed and 8% require maintenance. There should be continuous sensitization of the public on the importance of geodetic controls and the dangers of their destruction.

Geodetic control of the technical condition of buildings

Problems related to ensuring the control of the state of cultural heritage objects have existed for a long time. Their solution requires timely monitoring and consideration of effective algorithms for collecting and processing information. The object of the study is a building that has the status of an architectural heritage monument. The article describes the result of a study that was conducted to analyze the effectiveness of the instrumental geodetic method in assessing the technical condition of architectural heritage monuments. The research methods evaluated in the work were: determination of vertical movements of the foundation of the building and determination of the deformation characteristics of the building. Modern digital geodetic instruments were used in the implementation of this method. The purpose of the study is to analyze the application of the instrumental geodetic method as one of the main methods in assessing the technical condition of architectural heritage monuments. The instrumental geodetic method described in the article was based on empirical data obtained from direct geodetic measurements, conclusions are drawn about the technical condition of the monument. As a result of the research, it was found that the building has cracks, as well as the uneven nature of the foundation precipitation. At the end of the article, the authors were convinced of the need to use geodetic methods to assess the geometric parameters of buildings, gave recommendations for assessing the technical condition of architectural heritage monuments, and also described measures to preserve them.

Tolerances calculation for construction works and geodetic control during erection of reinforced concrete foundation columns for steel structures of thermal and gas-material pipeline overpasses

The purpose of the publication is to analyze the methods of calculations of accuracy of construction works and geodetic control of erection of reinforced concrete foundation columns for overpass steel structures of thermal and gas-material pipelines of oil refineries. For this purpose, a calculation methodology is considered, which takes into account operational technologies, including construction works and geodetic control, during the erection of the above-mentioned structures. The obtained results show that in order to ensure the standardized limit deviations of construction works, interrelated reasonable accuracy standards in the erection of structures are required, taking into account the average weighted average errors of geodetic control. In regulatory documents for the erection of structures are given accuracy standards (limit deviations) on their final position, and on geodetic control are given without taking into account the technological processes accuracy indicators of construction works. Setting the liability indicator of structures by purpose, we are establishing a confidence probability of ensuring the construction accuracy of the structure. To analyze the construction works and geodetic control accuracy we used the following methods: equal and negligible influence of deviation on the final position of structures and the method taking into account the accuracy of construction’s technological processes. In this publication examples of error calculations using the above mentioned methods are given. It is established that the most justified tolerances for structures erection are obtained when the method is applied taking into account the accuracy of their construction technological processes (by the accuracy indicator of technological process of construction works the limiting errors of geodetic control are established).

Geodetic control extension at erosion prone areas using integrated CORS-GNSS in Benin City, Edo State Nigeria

This study addresses the imperative expansion of geodetic controls in erosion-prone areas of Benin City, with a focus on establishing controls in specific schools. Two observation campaigns were conducted on nine monumented controls with 36 baselines and another set of eight controls with 28 baselines. Data adjustments were successfully carried out using Trimble Business Centre software, at 10.00σ confidence level and 1.00% significance for the tau test in the second iteration of both campaigns. Analysis revealed varying accuracy levels among stations. Notably, stations ADLC_01, ADLC_02, and QSS_01 demonstrated a minimum latitude accuracy of 1.3 mm, while AGGS_01 and AGGS_02 showcased the highest accuracy at 1.7 mm. Similar trends were observed in longitude and height measurements. For longitude, the maximum standard deviation (3.3 mm) was recorded at ENV_101D station, while the minimum accuracy (1.7 mm) was obtained at station AGGS_01. The minimum accuracy in height (3.5 mm) was recorded at station AGGS_01, while the maximum accuracy (6.7 mm) was recorded at station SMGGS_01. These findings provide essential insights into the accuracy of geodetic controls in Benin City based on purposeful selected schools, serving as valuable information for future research, infrastructure development, and engineering projects execution

An Investigation into the Stability of some selected Geodetic Controls in Lagos State of Nigeria using the Strain Analysis Technique

Natural disasters pose global challenges and can result in social, economic, and environmental damage, substantial loss of life, and even pose a threat to geopolitical stability. The study of such disasters through deformation modeling and analyses has found application in the disciplines of Geodesy and Geodynamics. The strain method has in fact been used to model deformation. The strain deformation parameters, namely, dilatancy, total shear strain and differential rotation, of this finite elemental model were calculated by using the baseline ratios of the coordinates of a classical traverse observed using the Global Positioning System (space technique), in the Minna datum platform. Computation was undertaken in a MATLAB programme and a MONTE CARLO environment, after the ill-conditioned triangles in the network were excluded. Statistical analysis was used to determine the significance levels of the respective deformation parameters at the 95%, 97.5% and 99.5% confidence intervals. After the statistical testing of the deformation parameters, it was observed that some of the controls were unstable in terms of their computed dilatancy and their total shear strain values. For the differential rotation of the network, the significance levels at the 95%, 97.5% and 99.5% confidence intervals were found to be 1.8743908, 0.9651796 and 0.4338522, respectively, while, on the other hand, the controls or centroids that did not respond to the network rotation had a mean value of approximately -0.99999.The minimal and maximal principal strain levels occurring at Centroids 11 and 36 with their triangulated station identities were found to be (36-12, 30-84, 43-34A) and (34-30A, 34-32A, 34-36A), respectively. The method adopted for this research proved to be very effective for a deformation study and analysis.

Geodetic Control of Structural Magnets of the Accelerating Facility at the Laboratory of High Energy Physics of the Joint Institute for Nuclear Research

Geodetic Control of Structural Magnets of the Accelerating Facility at the Laboratory of High Energy Physics of the Joint Institute for Nuclear Research

Influence of reference stations on the stability of the geodetic control network during deformation determination in the area of Kadzielnia in Kielce

Abstract Observations of land surface deformation are one of the important tasks of surveying, especially in landslide areas. They concern the determination in time of the magnitude of the deformation, on the basis of a stable reference system based on a geodetic control points. The whole measurement process can be divided into two parts. One part concerns the observation of reference points (geodetic control points) and the other the observation of the object itself. In the first, in addition to classical methods, GNSS (Global Navigation Satellite System) techniques based on reference stations are used. In the second, common observation methods such as laser scanning or photogrammetric methods using Unmanned Aerial Vehicles (UAV) are used. These observations are carried out in a specific time period in relation to the aforementioned geodetic control points. An area such as Kadzielnia in Kielce is covered by a long-term observation programme. A key element is the survey of the constancy of the geodetic control points, which are located in the epicentre of the survey. The survey of the constancy of the control points at Kadzielnia was based on a static method using SmartNet stations. Taking into account the fact that reference stations are treated as error-free reference points and that they operate 24 hours a day, it was decided to study the variability of their position over a longer period of time, as well as to determine the influence on the geodetic control points and to observe the deformation of the object during the measurement cycles.

The actual state of the geodetic and cartographic resources and legislation in Poland

Abstract Official data, including national geodetic and cartographic resources, are integrated in a spatial reference system. This study outlines national resources in Poland as an important part of the spatial information infrastructure in the European Community. They also provide reference data, including: geodetic control networks, base map, and topographic maps, for other resources of spatial data infrastructure. The study presents changes in the methods of sharing geo-data and technical standards for their collecting in the last few years, and additionally also presents some aspects of progressing geodetic and cartographic resources and legislation in Poland. It was noted that modern national geoportal or regional and district resources and progress, especially in the form of their standardization of presentation, enable to promote the use of spatial data in Poland and their popularization among the international community.

Positioning performance with dual-frequency low-cost GNSS receivers

Abstract In this study, positioning quality is tested with the use of low-cost in-house developed receivers. The analyzes consider the practical use of low-cost devices in surveying works. In the network solution, the accuracy of the GNSS positioning based on low-cost receivers can be characterized by the repeatability of the baseline length of 1 and 6 mm in 24 h and 10 min observation sessions, respectively. The field experiment of 4 GNSS receivers and 3 GNSS low-cost receivers allowed for establishing a precise geodetic control network. The accuracy of the control point coordinates determined with low-cost GNSS receivers equals a maximum of 17 and 40 mm for the horizontal and height components, respectively. Therefore, low-cost GNSS receivers can provide positioning accuracy at the some centimeter level and can support land surveying and geodetic monitoring activities.

CRBeDaSet: A Benchmark Dataset for High Accuracy Close Range 3D Object Reconstruction

This paper presents the CRBeDaSet—a new benchmark dataset designed for evaluating close range, image-based 3D modeling and reconstruction techniques, and the first empirical experiences of its use. The test object is a medium-sized building. Diverse textures characterize the surface of elevations. The dataset contains: the geodetic spatial control network (12 stabilized ground points determined using iterative multi-observation parametric adjustment) and the photogrammetric network (32 artificial signalized and 18 defined natural control points), measured using Leica TS30 total station and 36 terrestrial, mainly convergent photos, acquired from elevated camera standpoints with non-metric digital single-lens reflex Nikon D5100 camera (ground sample distance approx. 3 mm), the complex results of the bundle block adjustment with simultaneous camera calibration performed in the Pictran software package, and the colored point clouds (ca. 250 million points) from terrestrial laser scanning acquired using the Leica ScanStation C10 and post-processed in the Leica Cyclone™ SCAN software (ver. 2022.1.1) which were denoized, filtered, and classified using LoD3 standard (ca. 62 million points). The existing datasets and benchmarks were also described and evaluated in the paper. The proposed photogrammetric dataset was experimentally tested in the open-source application GRAPHOS and the commercial suites ContextCapture, Metashape, PhotoScan, Pix4Dmapper, and RealityCapture. As the first experience in its evaluation, the difficulties and errors that occurred in the software used during dataset digital processing were shown and discussed. The proposed CRBeDaSet benchmark dataset allows obtaining high accuracy (“mm” range) of the photogrammetric 3D object reconstruction in close range, based on a multi-image view uncalibrated imagery, dense image matching techniques, and generated dense point clouds.

Geodetic Measurement of Deformations of Load-Bearing Supports and Structures of the Komarovsky Market Building during its Operation

Komarovsky market is the largest covered market in Belarus and Europe. It started working in 1980. Until 2000, the operation of the market building was carried out without taking into account the uniqueness and increased requirements for objects of such type. The technical conditions and operating rules for the precast-monolithic reinforced concrete pavement shell with dimensions of 103´103 m have not been met. This led to the fact that individual elements were in a pre-emergency state. Scientists and specialists of the Belarussian State Polytechnical Academy carried out work on the examination of the technical condition and operational suitability of the Komarovsky market building. It is recommended to carry out geodetic control of coating shell deflections, deformations of side elements and supports at least once a quarter. To do this, a geodetic planned and high-altitude justification was created along the perimeter of the market building and on its mezzanines, from which deformations of the coating shell and side elements were measured. Therefore, the height position of the mezzanines was checked by the class-IV leveling. For mathematical processing of the results of high-precision geodetic observations in the Visual Basic language of the Excel editor, a complex “Geodetic Programs” was compiled, which is located on the Belarusian National Technical University website and in the local network of the University. For 21 years, the software package has been used by the authors not only to solver scientific and production problems, but also in the educational process. It is advisable to introduce programs in other educational institutions and industrial enterprises of the Republic of Belarus to solve the problems of engineering geodesy. The settlement measurements of the pile foundations of the market building were carried out by the class-II geometric leveling using КоNi 007 instrument. The coating shell deflections were determined by trigonometric leveling with a 2Т2 theodolite and a Leica TCR 1201 electronic tacheometer according special technique. An accuracy of the order of 1–2 mm was ensured by short sighting beams. The displacements of the onboard elements were measured with a theodolite and electronic tacheometer using the polar method and circular technique. During the geodetic control, the measured values of deflections of the coating shell, deformations of the side elements and pile supports did not exceed the established tolerances, which indicates the stability of all load-bearing structures of the Komarovsky market building.

VERTICAL ACCURACY EVALUATION OF THE FOREST AND BUILDINGS REMOVED COPERNICUS DEM (FABDEM) OVER THE PHILIPPINES

Abstract. This study evaluated the accuracy of the Forest And Buildings removed Copernicus DEM (FABDEM) over the Philippines. The evaluation was conducted at the country and island levels using 17,013 Geodetic Control Points (GCPs) partitioned into 3 independent sets. Results suggest that the FABDEM generally underestimates terrain elevation in the Philippines, as exemplified by a mean error of −1.44 m which is the average among the three sets of the GCPs used. Negative errors are primarily dominant in Luzon Island in the northern part of the Philippines, and positive errors are prevalent in the Visayas and Mindanao islands. At the country level, the DEM has an average Root Mean Square Error (RMSE) of 4.74 m and average linear errors of 7.80 m and 9.80 m at 90% and 95% confidence levels, respectively. At the island level, the DEM's accuracy varies, with some islands having RMSEs as low as 3.03 meters and as high as 5.80 m. This DEM is also most accurate at elevations less than 100 m and slopes less than 2 degrees. Care must be taken when applying the FABDEM in an archipelagic country like the Philippines due to several factors, such as the general tendency of this DEM to underestimate elevations, the dominance of negative errors in the northern part of the country, the differences in accuracies of elevations from one island to another, and the pronounced influence of elevation and slope to its accuracy. Nevertheless, the FABDEM is one of the most accurate among several freely available global DEMs covering the Philippines. Its accuracy in Mindanao Island is comparable to AW3D30 and superior to SRTM DEM.

VERTICAL ACCURACY ASSESSMENT FOR OPEN-SOURCE DIGITAL ELEVATION MODEL: A CASE STUDY OF BASRAH CITY, IRAQ

Abstract. In the diverse domains of earth observation, elevation data are essential for a wide range of applications with various technical requirements and use cases. The Advanced Spaceborne Thermal Emission and Reflection Radiometer-Global Digital Elevation Model (ASTER GDEM), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), Shuttle Radar Topography Mission (SRTM), and other projects have made a large number of global Digital Elevation Model (DEM) datasets for environmental modelling and studies freely available. Global DEMs have undergone an accuracy review to measure their inherent vertical uncertainty to show how accurate information should be considered while planning and analysing. Comparing the DEMs with highly accurate geodetic control points as the independent reference data one of the best methods in the evaluation process. SRTM 30m, SRTM 90m, ALOS World 3D-30, Aster-GDEM, GMTED2010, and NASADEM are among the worldwide DEMs that were examined. Comparisons are made between 793 geodetic control points values and those from SRTM 30m, SRTM 90m, ALOS World 3D-30, Aster-GDEM, GMTED2010, and NASADEM. The statistical analysis of global DEMs from GPS reference elevations gave us that the accuracy of the ALOS World 3D-30m is much better than other models with RMSE and STD values of 1.2497 and 1.235 m, respectively. In contrast, Aster-GDEM exhibited the highest RMSE and residual error of STD values of 5.793 m and 3.394 m, respectively.

Effect of Large Height Difference on Global Positioning System Solutions from a Commercially Available Software Package

Commercially available global navigation satellite system (GNSS) processing software is user-friendly and can be used in a wide variety of positioning applications from establishing geodetic control over large regions to deformation monitoring on a local scale. It is important to study the accuracy of positioning from commercial software for presurvey planning. Previously, this was done in several studies; however, none of them focused on the effect of large height differences in positioning solutions. It is known in the literature that large height differences on a baseline degrade GNSS solutions. In this study, we investigate the effect using TOPCON MAGNET v 4.0.1 through analysis of continuously operating reference stations (CORS) in California, US. Because the effect of height differences on global positioning system (GPS) baseline components has not yet been properly quantified, the positioning accuracy standards given in the surveying guidelines may not be appropriate and are often overoptimistic. When the height difference was less than about 300 m, the root mean square error was about 2–3 mm for the horizontal components and about 20 mm for the vertical component for baseline lengths of 10–20 km. However, for a height difference of 1,500 m, the error became 5–8 mm for the horizontal and 70 mm for the vertical components. In all cases, the vertical error was greater than the horizontal by a factor of 5–9, which is much greater than the expected 2–4 for GNSS. These results are likely only applicable to the version of the MAGNET software used in this study.

Photogrammetric and geodetic control of laying work

Photogrammetric methods in building control with the development of modern technologies prove their effectiveness in comparison with geodetic ones. The construction and inspection of buildings, structures, complex equipment can be provided at each stage with the results of aerial surveys and the construction of three-dimensional models on their basis for high-quality control of processes. In the control and executive surveys of structures under construction, photogrammetric methods are also used as an alternative or as an addition to traditional geodetic surveys. Such a replacement is especially effective in geodetic support for the construction of unique structures of complex architecture. The article describes a detailed overview of the control procedure, stages of work and formulas for calculations. The results obtained indicate good convergence of geodetic and photogrammetric executive surveys and high-quality performance of geodetic works. And the rapid development of instrumentation and the improvement of photogrammetric measuring systems using digital technologies and machine vision make it possible to increase the accuracy of determining the position of points in images up to 0.1 mm. The issues considered in the article expand the range of tasks to be solved in the field of construction control.

Rational methods of geodetic control of technogenic consequences of the development of oil and gas fields

The methods of controlling the consequences of the influence of manmade geomechanical processes caused by the extraction of hydrocarbons from the subsurface in the fields under development are considered. The possibilities of methods from the standpoint of separate determination of spatial and temporal quantitative parameters characterizing the deformed state of the skeletons of reservoirs and host rocks, the entire thickness of the rock mass above the deposit in an uneven field of compressive stresses and deformations of the earth’s surface are shown. The inconsistency of methods of classical repeated leveling, geodetic positioning and traditional radar interferometry in connection with the low level of representativeness of their results is noted. scientific novelty lies in the development of ways to improve the effectiveness of the method of radar satellite interferometry. As a result, the conditions for the effective use of radar satellite interferometry on the basis of a network of stationary points which coincide with the points of the leveling network method of spot geodetic sounding of deformation processes in the oil and gas fields under development have been determined and characterized.