Geodetic Practice Research Articles

ENGINEERING-GEODETIC SURVEYING. GEOMETRIC LEVELING OF THE ROUTE

The purpose of leveling the route is to determine the elevations of all the control points, including the beginning, middle, and end of curves, plus points, and points on transverse profiles. Longitudinal and transverse leveling is carried out after the route has been set out. The results of leveling (elevation measurements) are subsequently used for constructing the longitudinal profile of the route and the transverse profiles.The paper outlines the main principles and methods of leveling, taking leveling readings on rods, referencing the road route to benchmarks, leveling junction and intermediate points, balancing elevation differences, and calculating junction and intermediate points. The paper also describes the control of route leveling and plotting the projected line on the longitudinal profile.Engineering-geodetic surveying, specifically geometric leveling of the route, is an important component of educational geodetic practice. Geodetic practice for students is conducted according to the academic curriculum and serves as a continuation of the learning process in the field. It completes the theoretical course and is conducted according to the academic plan. During practical training, students acquire skills in working with geodetic instruments and processing the results of field measurements, becoming familiar with the main types of engineering-geodetic work during surveys and construction of engineering structures. Students are required to participate in all types of work, conduct the necessary measurements, and process them in the office. Practical training in geodetic practices provides students with hands-on experience in applying theoretical knowledge to real-world scenarios. Through fieldwork, students gain proficiency in using a variety of geodetic instruments such as levels, total stations, and GPS receivers. They learn how to set up and operate these instruments accurately to collect precise measurements of elevation and distance. Furthermore, students learn the importance of teamwork and collaboration during field surveys. Working together with peers, they divide tasks, communicate effectively, and problem-solve on-site challenges that may arise. These collaborative experiences not only enhance their technical skills but also cultivate essential soft skills such as leadership, communication, and adaptability.

Щодо підвищення точності аналітичних та чисельних методів геодезичних та картометричних операцій

Purpose of this work is to determine and justify the use of analytical and numerical geodetic and cartometric methods on the reference ellipsoid, as well as their calculation accuracy in the geographic information environment. Methodology. The research compiled a register of geodetic and cartometric methods used in geodetic practice and implemented in modern geographic information systems. Standard tools in GIS often use approximate numerical methods, which affects the accuracy of models of geospatial objects in the GIS environment. Therefore, we have analysed and established for each operation of geodetic and cartometric methods a mathematical model that determines a particular cartometric property with maximum accuracy either by analytical or numerical methods with the number of terms in the binomial series of 6 or more. Results. The author proposed 10 operations of the geodetic method and 3 operations of the cartometric method, for which mathematical models and their accuracy were established and substantiated with their corresponding implementation in the MATLAB v. R2018a. The defined list of geodetic and cartometric operations made it possible to move away from the classification of distance lengths that influenced the further use of certain surfaces (map projection plane, sphere, spheroid, or reference ellipsoid) and mathematical models of operations. The presented mathematical models allow performing the relevant geodetic and cartometric methods with maximum accuracy using modern computer technologies. The mathematical models of geodetic and cartometric methods are investigated, which have practically no limitations for achieving the required accuracy, especially for large and ultra-large distances. The scientific novelty of the research is to define and justify a clear list of mathematical models of numerical and analytical geodetic and cartometric methods instead of cartometric methods on the map and standard methods of instrumental GIS; using the surface of the reference ellipsoid, and not just cartographic projections, spheroid or sphere. The practical significance of the research lies in the use of numerical and analytical geodetic and cartometric methods that significantly increase the accuracy of operations in these works, as well as in the creation/updating of digital topographic maps, navigation and route planning, etc. The research results can be concluded that well-founded mathematical models will ensure an increase in the accuracy of computational operations taking into account the curvature of the Earth in all sectors and areas of the economy, which will affect the quality of accounting and monitoring of relevant objects, integration and geospatial analysis of heterogeneous geospatial data, improve the quality (topological consistency) of geospatial data, etc

THE ROLE OF GEODESY IN THE DEVELOPMENT OF DRONE TECHNOLOGIES FOR MEASURING, MAPPING AND MONITORING TERRITORIES

This study examines the relevance and importance of integrating geodetic methods into remote sensing technology from drones. The main focus is on exploring the possibilities of drones as an innovative tool that opens up new perspectives for measuring, mapping and monitoring territories. Advanced geodetic technologies and their applications in drone work are analyzed, including photogrammetry, laser scanning, and other data collection methods. The purpose of the article. Defining and systematizing the role of geodesy in the advancement of drone technologies used for precise measurements, mapping and monitoring of territories. Research task: to analyze the current state of geodetic methods in the context of their application in drone technologies; explore the possibilities of using unmanned aerial vehicles for geodetic work. Develop recommendations for the integration of drone technologies into geodetic practice. Research methods: analytical method - a systematic analysis of scientific publications, articles and reports that highlight current issues of geodesy and drone technologies, their development and application; empirical method - data collection and processing using drones, measurement, monitoring and mapping to assess the accuracy and effectiveness of these technologies; experimental method - conducting field tests of drone technologies to collect primary data, analyze them and compare them with traditional geodetic methods. An important part of the research is the evaluation of the effectiveness of the use of drones in comparison with traditional methods, with a special emphasis on increasing the accuracy, speed and reducing the cost of surveying work. The influence of legal aspects on the use of drones in geodesy is also considered, including the possibility of its adaptation to modern geodetic needs.

Borneo triangulation 1968: a review and the way forward

Triangulation is a classical geodetic practice to establish survey control networks by using measurements of angles and some spare distances. In this way, a series of reference points or simply called ‘trigs’ is spreading over the country. This paper aims to review geodetic survey work that was carried out for the East Malaysia and Brunei from 1918 to 1968 which is covering about 204,119 square kilometres'. However, this classical geodetic datum is not directly compatible with the current surveying trends based on Global Navigation Satellite System technologies. Therefore, in this review covered concepts and history of triangulation systems, datums and the status of transformation plan to modernise geodetic datum for Sarawak.

Using the average air temperature along the trace for atmospheric correction in laser ranging: accuracy analysis

One of the factors affecting the results of laser ranging measurements on ground-level traces is the difference between the speed of light propagation in the Earth’s atmosphere and the speed of light in vacuum. This difference is accounted for by the introduction of a correction for the mean integral refractive index of air along the measured trace. Research to improve the accuracy of such a correction is one of the most important scientific fields in geodesy and metrology. At the same time, the empirical approach to accounting for the atmospheric influence, which does not have a strict justification, is used in geodetic practice and involves determining the mean integral refractive index by the average air temperature along the measured trace. The paper is dedicated to the analysis of the accuracy of this empirical approach and to the estimation of the possibility of its application for providing traceability in the practice of linear measurements.

GEODETIC SUPPLY FOR THE CONSTRUCTION OF ENGINEERING STRUCTURES

The construction of engineering structures when transferring the project to the area is impossible without geodetic work. The composition and sequence of engineering and geodetic works depend on the features of the design and construction of facilities and the type of structure. The purpose of the article is to consider geodetic works in the construction of engineering structures. The issues of performing engineering and geodetic works during the construction of structural elements of the bridge are considered. During the construction process, it is necessary to ensure full compliance with the design documentation and high accuracy of work performance. These requirements can be achieved by using high-precision geodetic works with constant monitoring of the installation work. At all stages of the bridge construction, geodetic works accompany the transfer to the terrain of the bridge axis, the resistance axis, perform a detailed breakdown during the construction of resistances and the installation of purlins. Also, the construction of individual parts of the building is constantly monitored, the dimensions and shape of the mounting elements are checked. When building large structures, it is necessary to have information about the points of the geodetic base of the bridge crossing, an extract from the catalog of coordinates and elevations of the geodetic base. The breakdown is carried out by tying to the points of the geodetic reference network, which has coordinates in the absolute or conditional system. Modern construction requires the use of new technologies and methods for performing geodetic work related to the introduction of electronic devices and programs for automated information processing into geodetic practice. Currently, a large number of geodetic instruments and new technologies in geodesy have been created, which differ from traditional ones. To carry out survey work, geodetic instruments, such as electronic total station and levels, were used. The electronic total station measures distances, angles and processes data directly in the process of field work, has an internal memory where it can store all the data obtained as a result of measurements. The digital level has a device for automatic registration of measurements along the rail and a processor for subsequent processing of all leveling results. During measurements, the device measures the distance to the rail and the elevation between points. This eliminates two main types of errors: observation errors when taking a reading and error in distance measurements. During the construction of supports, a temporary rapper is installed on each of them, which is tied to permanent rappers by leveling moves. The removal of marks on the supports is carried out by methods of geometric or trigonometric leveling. The coordinates of the rappers were received and entered into the local plan. Marks for serifs of the device with a retroreflective effect were pasted on the bridge supports. The data of coordinates and heights were entered into the total station memory. Geodetic work carried out during the construction of the span structure ensures the accuracy of its assembly in accordance with the project. After the installation is completed, the assembly results and deviations from the project are monitored. The construction of structural elements of engineering structures must comply with building codes and geometric parameters of the facility design.

Horizontal Survey of Crane Paths

In general, the term deformation refers to a change in the shape of the observational object. In geodetic practice, it is accepted consider deformation as a change in the position of the object relative to of any original provision.

ANALYSIS AND GENERALIZATION OF REGULATORY SUPPORT FOR GEODESIC SUPPORT OF ROAD CONSTRUCTION OBJECTS

The transfer of the project to the site requires the performance of measurements and constructions with high accuracy. Changes in the technology of geodetic works related to the computerization of geodesy, the introduction into geodetic practice of electronic geodetic instruments and automated processing programs, require the introduction into production of both traditional methods of geodetic measurements and new technologies and methods of geodetic works. Despite the fact that geodetic works are an integral part of construction, in the regulations on surveys, design and construction of roads and man-made structures quite limited regulation of the content of work on the transfer of projects to the field, division work, executive surveys, geodetic quality control, accuracy requirements, etc. Given the current state of regulatory and legal support for geodetic support of road construction sites, it is advisable to develop a national standard for the implementation of geodetic surveying and geodetic control in the construction of road construction sites. This standard will supplement the main provisions of regulations on the construction of roads and transport facilities. With the growing volume of design, construction and overhaul of roads, it is necessary to standardize all stages of design and construction work, including those related to geodetic production. The development of technologies and methods of geodetic works related to the computerization of geodesy requires the introduction into production of both traditional methods of geodetic measurements and new technologies and methods of geodetic works. Based on the analysis and generalization of regulatory support for geodetic support of design and construction of roads and artificial structures, the need to develop a national standard for geodetic surveying and geodetic control in the construction of road construction as a supplement to the basic provisions of regulations on road construction and transport facilities.

Геодезическое обеспечение использования технологии лазерного сканирования для фиксации памятников культурного наследия

Preservation of cultural heritage is associated with their fixation by performing measurements. They are very effective when we use the terrestrial laser scanning method, as a means of obtaining the most complete and reliable information on the geometry of the object at a particular time. However, the method of laser scanning is not so widely represented in the technical literature, for instance, on Totalstation- or theodolite surveys due to the relatively recent introduction in geodetic practice, especially for the purposes of fixing monuments. There are many questions on application of this technology for the above mentioned aim, they focus on ensuring the required regulatory or its accuracy. The authors discuss a geodetic method for ensuring the precision of laser scanning surveys including the design and estimating the fixed control points’ exactness, as well as the tie ones. The influence of angular and linear measurements over the laser positioning accuracy is shown. The technique is demonstrated, including modeling design schemes and their comparison with actual data. The research results are confined to the world-class cultural heritage site of Baalbek temple complex in Lebanon.

ELECTRONIC EDUCATIONAL RESOURCES DURING THE CONDUCT OF A BUSINESS GAME WITHIN THE FRAMEWORK OF GEODESIC PRACTICE

The article discusses the process of applying electronic educational resources during a business game as a part of the geodetic practice of university students. The specifics of the selection of electronic educational resources to support business games are noted and the resources most often requested by students during role-play classes are determined.

АЛГОРИТМЫ ВЫЧИСЛЕНИЯ ГЕОДЕЗИЧЕСКИХ ВЫСОТ И ШИРОТ ПУНКТОВ ПО ПРЯМОУГОЛЬНЫМ КООРДИНАТАМ В ПЛОСКОСТИ МЕРИДИАННОГО ЭЛЛИПСА

Owing to the widespread use of GNSS technologies in geodetic practice, the problem arises of transition from rectangular spatial coordinates of points to spatial geodetic coordinates, which are necessary for the transition to flat rectangular coordinates in the Gauss-Kruger projection. The authors proposed five algorithms for converting rectangular coordinates of points in the plane of the meridian ellipse into geodetic heights and latitudes. The first two algorithms are geometrically related to the intersection point of the ellipse with the normal passing through the point at which the rectangular spatial coordinates were obtained. The formulas of the other three algorithms are based on the geometric relationships of the point of intersection of the meridian ellipse with the straight line connecting the point with the center of curvature of the meridian. As a result of the experiments, deviations of the calculated latitudes and heights from the reference values of the given grid of geodetic coordinates were obtained. The formulas were tested not only for points under and on the earth's surface, but also outside the earth at different heights up to an altitude of 20,000 km.

Hybrid environments for training engineering students the basics of working with geodetic equipment

Problem and goal. The article describes an approach to solving the actual problem of identifying effective and approved by students blended learning tools in the initial stages of working with equipment for engineering education courses. The goal of the research was to study the applicability of hybrid environments of simplified configuration for learning work with geodetic equipment based on interactive virtual educational tools and students' mobile devices in the Novosibirsk State University of Architecture and Civil Engineering (Sibstrin). Methodology. A variant of hybrid laboratories with a virtual component and a variable (on-site or mobile) physical component is quite new for pedagogical research. The physical component is important when learning geodetic equipment since stationary devices are studied at university laboratories when portable analogs are used in real geodetic practice. The virtual component of a hybrid environment during initial work with engineering equipment can be represented by a set of multimedia educational tools that simulate the operation of engineering instruments and devices with a high degree of interactivity which available on one online platform for a specific engineering course. Results. The study found that the presented configuration of the hybrid environment is effectively applicable for initial work with geodetic equipment and is approved by students both during laboratory work in an on-site stationary laboratory, as well when using portable equipment and mobile devices in geodetic practice. Conclusion. For the initial stages of training students for working with geodetic equipment, a hybrid learning environment configuration is proposed based on interactive virtual educational tools and mobile devices which is an affordable and functional solution for engineering universities. Virtual e-learning tools can be accumulated on the site with online support for a separate engineering course and supplemented by means of distance interaction and cooperation of the lecturer and students. The hybrid environment can be used for initial training when working in a stationary laboratory or for conducting a professional business game or individual practical tasks on the ground with portable geodetic equipment.

Программный комплекс для определения кренов сооружений башенного типа по данным наземного лазерного сканирования

The authors describe a software suite for determining tilt degrees of tower-type structures according to ground laser scanning indication. Defining the tilt of the pipe is carried out with a set of measured data through approximating the sections by circumferences. They are constructed using one of the simplest search engine optimization methods (evolutionary algorithm). Automatic filtering the scan of the current section from distorting data is performed by the method of assessing the quality of models constructed with that of least squares. The software was designed using Visual Basic for Applications. It contains several blocks (subprograms), with each of them performing a specific task. The developed complex enables obtaining operational data on the current state of the object with minimal user participation in the calculation process. The software suite is the result of practical implementing theoretical developments on the possibilities of using search methods at solving optimization problems in geodetic practice.

Functionality and reliability of horizontal control net (Poland)

Abstract Horizontal control networks established with monuments are functional if the conditions related to the number of control points, their density, condition and stability of coordinates are met. For functionality defined in those terms, deterministic accuracy characteristics are of little use. The subject matter discussed herein includes the two key features of geodetic control points, i.e., usability and stability. Due to the varying properties of those variables and the impact of the operating time of the system, there is no alternative to reliability-based approach in developing the functionality model. The measures of functionality and the procedures of data acquisition for developing the model of the control network destruction process have been defined. The solution presented herein is relevant for geodetic practice, providing a standard procedure for defining the time frame and the scope of the control network upgrading. The identified destruction process model optimizes this task assuming critical states expressed by the functionality probability. The applied approach is an example of the reliability theory-based approach typical for engineering. The issue of simulating the destruction process is illustrated with the results of the tests of class 3 control networks conducted in Kielce and Lodz regions in Poland. As a result of the tests, the characteristic properties of the control network destruction process have been identified. It was also shown how the patterns of usability and accuracy of the geodetic control points are relevant on the stage of implementing investment project tasks.

ПРОЕКТИРОВАНИЕ И ОЦЕНКА ГЕОДЕЗИЧЕСКИХ НАБЛЮДЕНИЙ ЗА ДЕФОРМАЦИЯМИ ОБНАЖЕНИЙ ВЫЕМКИ ПРИ СТРОИТЕЛЬСТВЕ СТАНЦИИ МЕТРОПОЛИТЕНА

In geodetic practice, the use of robotic total stations in monitoring the deformation processes becomes the norm. In this case, various software systems for processing the measured values and their visualization are used. At the same time, issues of optimizing the deformation network and interpreting the results of observations remain very relevant today. In addition, ensuring the stability of control (initial) points still remains a problem in solving various tasks, and above all in monitoring observations. Previously, it was apriori assumed that the starting points located outside the zone of influence of the observed object are considered stable. However, to achieve reliable results with various measurements, the stability of the starting points should be checked and this should be considered as an additional monitoring parameter. There are developments in this direction, and they are related to the consideration of displacements and deformation marks and starting points in a single system (network). The research results presented in this article are novel in terms of the methodology and algorithm for calculating the coordinates of observation stations, deformation marks, and starting points without building a single network. At the same time, each observation cycle provides an assessment of the stability of all points. The observation technique was developed in relation to the construction of an engineering structure: an excavation for the subway lobby. The issues of optimizing the location of observation stations, deformation marks (points), and assessing the accuracy of their displacements are successively considered. When analyzing the relative displacements of the deformation marks, the ellipses of the error of the position of the points are compared. If the resulting displacement between the measurement cycles goes beyond this ellipse, then speaking about the significance of the displacement and its direction is allowed. A simplified method for detecting the displacements of the starting points by comparing the elements of the residual matrices determined in different observation cycles is also considered.

Integration of GNSS and Satellite InSAR Data: Derivation of Fine-Scale Vertical Surface Motion Maps of Po Plain, Northern Apennines, and Southern Alps, Italy

Global Navigation Satellite System (GNSS) and satellite synthetic aperture radar (SAR) interferometry represent the most important space geodetic techniques usually exploited to measure millimetric ground deformation on earth surface at both local and wide-area scale. SAR images processed with persistent scatterers interferometry (PSI) multitemporal approach lack of an absolute reference datum. In this paper, SAR images are calibrated with data derived from permanent GNSS stations, in order to obtain absolute and more accurate displacement values. The method used to correct PSI with GNSS is based on existing methodologies commonly applied in the geodetic practice of combining crustal and local deformation studies with geospatial statistical analysis. The spatial distribution of vertical terrain deformations and their temporal changes are coherently measured, leading to a fine-scale surface velocity map in the central-eastern Po Plain, Northern Apennines, and Southern Alps in Italy. The results reveal significant subsidence rates on the north-western Adriatic coast including the Po Delta and the lagoon of Venice, as well as on Bologna and Ferrara cities in agreement with long-term displacement motion values provided by geological data and other previous works performed at local scale. This paper demonstrates the importance and effectiveness in creating a single, unique surface motion map by merging different data sets in which geodesy plays a relevant role in the datum alignment of PSI products before the stacking of the SAR maps.

Helmert transformation with mixed geodetic and Cartesian coordinates

It is common in geodetic practice that station geodetic coordinates in an old frame are measured/estimated by adjusting conventional leveling and vertical networks (together with a vertical datum), whereas their Cartesian coordinates in a new frame are measured/estimated by adjusting modern 3D Global Navigation Satellite System (GNSS) networks. To estimate Helmert transformation parameters between the two frames, one can simply convert the geodetic coordinates to their Cartesian counterparts in the same frame, and then perform a least-squares transformation with Cartesian coordinates in both frames. This stepwise approach is not optimal because of nonlinearity in the first step. In this work, a direct transformation is conducted. A functional model with mixed geodetic and Cartesian measurements is followed, and a realistic stochastic model considering measurement errors in both frames is adopted. Correlations between common and non-common stations are also taken into account. Weighted least-squares estimates of the transformation parameters and transformed/adjusted coordinates in the new frame are derived in detail, the latter representing the enlarged network of the new frame. Simulations are conducted, and the results validate the superiority of the proposed method compared with the stepwise method.

On the statistical power of Baarda’s outlier test and some alternative

Abstract Baarda’s outlier test is one of the best established theories in geodetic practice. The optimal test statistic of the local model test for a single outlier is known as the normalized residual. Also other model disturbances can be detected and identified with this test. It enjoys the property of being a uniformly most powerful invariant (UMPI) test, but is not a uniformly most powerful (UMP) test. In this contribution we will prove that in the class of test statistics following a common central or non-central χ2 distribution, Baarda’s solution is also uniformly most powerful, i.e. UMPχ2 for short. It turns out that UMPχ2 is identical to UMPI, such that this proof can be seen as another proof of the UMPI property of the test. We demonstrate by an example that by means of the Monte Carlo method it is even possible to construct test statistics, which are regionally more powerful than Baarda’s solution. They follow a so-called generalized χ2 distribution. Due to high computational costs we do not yet propose this as a ”new outlier detection method”, but only as a proof that it is in principle possible to outperform the statistical power of Baarda’s test.

Accuracy validation of Croatian official geoid solutions over the area of City of Zagreb

Height (altitude) determination in geodesy is faced with problems that are directly attributed to the method of measurements and used geoid solutions. Due to the reliability of CROPOS as well as growing progress in geoid determination (increase of their external and internal accuracy), GNSS observations using CROPOS_VRS_HTRS96 VPPS service became most commonly used method of height determination in Croatian every day geodetic practice. This paper describes establishment of 33 GNSS/levelling points using CROPOS_VRS_HTRS96 VPPS service and geometric levelling at the area of the City of Zagreb. It also gives the analysis of the quality of performed GNSS observations, analysis and comparison of the geoid undulations from official geoid solutions of the Republic of Croatia, HRG2000 and HRG2009 with undulations obtained by GNSS/levelling for established GNSS/levelling points and brief overview of current state of vertical network of the City of Zagreb.

Topographic Maps with Infrared Colors

We are introducing infrared security print as an extension for topographic map print. The article carries out the algorithm of merging several layers of spot colors. We expand the spectral analysis of dyes to the near infrared spectrum. Today's technology of topographic map multiplication uses spot colors defined by experts in the state geodetic bureau. The state map production is strictly defined by law. That indirectly emphasizes the need to protect the data displayed on produced maps. We suggest, while creating maps, adding infrared properties to the colorants for the authentication of every edition. As the official geodetic practice set RGB color values, it is possible to carry out double printing colorants for these colors, which have the same response in the visual spectrum and a different in the infrared spectrum. Based on the equalization of spectrum pairs of dyes in the visual part, a proposal was given for the degree of light absorption in the infrared region. Every publisher, printer, expert from the state geodetic bureau, determines his own level of infrared safety component participation. Such a map cannot be changed, ie; forged, thus ensuring full protection for all topographic data contained on the state map. Infrared dyes property disappears in an attempt of recording, scanning, or any other technology that allows reproduction. The visual state of the topographic map with infrared colors, is the same as the visual state of the map without the IRD extension. With this procedure there is no interference with the visual art on the map. This method of printing also allows creation of maps, with pieces of information in the visual spectrum that may not be the same as the content of information in the infrared spectrum.