Geodetic Survey Research Articles

Use of data from digital engineering and topographic plans on the territory of the construction site

To date, the construction and reconstruction of buildings and structures is carried out by a number of different construction organizations. As a rule, one organization is the customer, announces a tender for construction and installation work, then one or more contracting organizations win as a result and begin to perform work according to the terms of reference. Contractors, in turn, can participate in the same types of work, as well as at different stages. Depending on the level and technical competence of specialists in contracting organizations, it is very often necessary to face production problems in the execution of the technical assignment and compliance with the project for various types of work performed, which include: work performed with errors (non-compliance with design data or values), hidden defects, work not performed in full, etc. In connection with the above, it is required to have control geodetic surveys, executive materials at each stage and throughout the construction of the structure, as well as during its further operation. Because of this, there is a need to create a database of digital engineering and topographic plans on the territory of the entire construction site. Having such a database, in the event of any dispute between the customer and the executors or the controlling organization of the customer, it is possible to restore in detail each stage of the life cycle of the structure under construction.

Current Slip and Strain Rate Distribution Along the Ganzi-Yushu-Xianshuihe Fault System Based on InSAR and GPS Observations

The Ganzi-Yushu-Xianshuihe fault (GYXSF), a large strike-slip fault located on the east side of the Tibetan Plateau, has seen high seismic activity in recent years. However, despite the earthquake risk posed by this fault, there is a lack of high-resolution geodetic survey results regarding the current slip rate. We have used 4-track ascending and 5-track descending Sentinel-A/B SAR Interferometric Synthetic Aperture Radar (InSAR) data from 2014 to 2020, to obtain the current slip rate of the entire GYXSF within the radar’s line of sight (LOS), with high resolution. Both InSAR and published Global Positioning System (GPS) data were integrated to calculate a high-resolution three-dimensional deformation field and strain rate field of the GYXSF. We have also used the screw dislocation model to calculate current slip rates in the fault-parallel direction at 20 km intervals. The key findings of our study are as follows. (1) The current slip rate of the GYXSF is segmental: the slip rate of the Ganzi-Yushu fault (GYF) gradually increases from ∼1 to ∼6 mm/yr from the north-west to the southeast, while the slip rate of the Xianshuihe fault (XSF) increases from ∼8.5 to ∼12 mm/yr from the north-west to the southeast. (2) There are non-negligible post-earthquake deformations along the GYXSF, and our best fitting results show that an approximately 100 km long section of the GYF has undergone post-seismic after-slip in the 4–10 years since the 2010 Yushu M 6.9 earthquake, with a maximum creep of ∼2.2 mm/yr (3) The strain rate is dispersed in the GYF region but concentrated on the fault in the XSF region. There is also a measurable strain rate on secondary faults north of the GYXSF, implying the seismic hazard of these secondary faults cannot be ignored. (4) The continuous deformation and block-like models are the best models to explain the observations and deformation characteristics of the GYF and XSF, respectively.

Non-Contact Diagnostics of the Geometry of a Historic Wooden Building as an Element of Periodic Safety Assessment.

The article presents a method of non-invasive diagnostics of a historic wooden church, built in the 18th century. Over the hundreds of years of its use, changes in the geometry of the structure have been observed. This article presents the requirements of so-called architectural and geodetic survey and the method of using terrestrial laser scanning to create a three-dimensional solid model of an object. The diagnostic tests performed made it possible to perform analysis based on a so-called point cloud, which is a virtual representation of a real object. In order to determine the basic parameters of the building, the area and volume of all rooms were determined. It was found that the object exhibited deformations that cannot be explained solely as a result of imperfections during climb and normal wear and tear during operation. Therefore, the changes in shape were assessed in detail by means of an assessment of the verticality of the pillars supporting two levels of the church, the verticality of the walls, and the inconsistency of the floors, as well as the shape and horizontality of the roof edge. Additional InSAR and FEM tests of the object’s location on the ground allowed identification of the cause of the object deformation as the influence of inhomogeneous groundwater relations under the building. Without prophylactic measures, this deformation phenomenon can be expected to worsen. The tests described should therefore be considered as essential in subsequent diagnostic cycles and permit future extended numerical FEM analysis.

ИНЖЕНЕРНО-ГЕОДЕЗИЧЕСКИЕ ИЗЫСКАНИЯ ДЛЯ ЦЕЛЕЙ ПОДГОТОВКИ ПРОЕКТНОЙ ДОКУМЕНТАЦИИ ЛИНЕЙНОГО ОБЪЕКТА

Engineering and geodetic surveys in the modern world have become an integral part of any construction. Most often they are used when laying linear objects, being the basis of the design process for them. The authors of the article on the example of the Sakhalin-1 project. Stage 2 development. Field gas pipeline BP Chayvo - BKP Chayvo” reviewed the process of engineering and geodetic surveys for the preparation of design documentation for a linear facility. First of all, the order of actions was planned and methods for achieving the set goal were chosen. Thus, 8 main stages of work have been identified, thanks to which it is possible to obtain a complete picture of the area, which includes the relief, the existing layout, and buildings and structures. At the first stages, it was decided to study the existing geodetic base, which is the basis for the creation of a satellite geodetic density network. Further actions were the implementation of the creation of a network of base stations, a geodetic network of identification marks and control points. The role of laser scanning in engineering and geodetic surveys has long been known and is of great importance in carrying out such work. In this case, obtaining the initial data for compiling topographic plans is carried out through airborne laser scanning and aerial photography. As a result of a complex of works on aerial laser scanning and aerial photography, materials called images are created. In the process of cameral work, the images are deciphered, and then a topographic plan of the area, a digital terrain model and a digital terrain model are compiled. Thus, thanks to the implementation of a set of works through engineering and geodetic surveys, an engineering and topographic plan of the area was obtained with all the necessary characteristics for compiling project documentation for the project being implemented.

ОБ ОПРЕДЕЛЕНИИ И УЧЕТЕ КОЭФФИЦИЕНТА РЕФРАКЦИИ НА СТРОИТЕЛЬНОЙ ПЛОЩАДКЕ

Taking into account the refraction in modern total station is performed by inputting the refrac-tion coefficient into the memory of the device. The article develops a formula to determine the refrac-tion coefficient based on geodetic surveys (zenith distances, horizontal positions, elevations) and pro-vides field survey results. The article proposes the method for creation of the vertical basis (a geodetic structure consisting of the points fixed on a vertical plane on one vertical line and ground points with highly accurate differences in elevations determined between them).The article provides experimental survey results in determining the diurnal variation of the refraction coefficient which showed that in the morning and at night the refraction coefficient values are positive, and in the day and in the even-ing they are negative. There is a recommendation for the construction site to determine the refraction coefficient every half hour to increase the accuracy of the results. The variation of the coefficient within half hour shall not exceed 0.2. If the refraction coefficient exceeds this value, then refraction corrections shall be introduced in the measurement results.

П’ЯТИКУТНА ВЕЖА МЕДЖИБІЗЬКОЇ ФОРТЕЦІ В ДОСЛІДЖЕННЯХ ЄВГЕНІЇ ЛОПУШИНСЬКОЇ

A detailed review and analysis of previous research is required for further study of the structural and functional features of the pentagonal “Knight's” tower in the defensive complex of the Medzhybizh fortress. The tower is located on the northwestern corner of the defensive walls of the Medzhybizh fortress. Its southeastern corner adjoins the modern entrance, and its northeastern corner abut onto the one-story building near the northwestern defensive wall. The tower is partially extended beyond the curtain line. During the architectural and restoration works, which began in 1968, the most significant contribution to the study of the tower was made by Yevgenia Lopushynska. The result of that activity is a topographical and geodetic survey of the territory, a examination of the monument, measuring works, a compiled report of the technical condition of the structure, a defective report of the building and the fortress, a restoration task and photo-fixation. Archival materials and library collections were also studied. The set of scientific and project documentation collected on this defensive structure is stored in the State Historical and Cultural Reserve "Mezhybizh" and fragments of it have published in scientific publications of the 90s of the last century. Thus, the paper presents the experience of architectural and archaeological research of the pentagonal tower in the Medzhybizh fortress carried out by the specialists of “Ukrproektrestavratsiya” (Kyiv) in the 60s-90s of the 20th century more detail.

Особенности построения графа автомобильных дорог для большегрузного транспорта

The study is aimed at improving highway alignment charts in order to improve the operating character-istics of highway sections, adapt them to regulatory requirements for heavy transport and reconstruct accident-prone sections based on information produced by state-of-the-art data collection systems for road objects without costly geodetic surveys. The article presents methods for constructing a digital preliminary trajectory of a highway using relationship databases and algorithms that implement these approaches according to data from video certification. As a result, a preliminary highway alignment chart that meets current regulatory documents is developed, including the impact severity of fences for heavy transport. It is noted that the problems of constructing preliminary alignment charts of high-ways for heavy transport in Russia could be solved without conducting costly geodetic surveys, but relying on digital trade and regional databases of road facilities, which are permanently updated by state-of-the-art data collection systems for road objects.

Investigation of Landfill Saturation Based on Periodic Aerial Photogrammetric Measurements

The actuality of the study of saturation in Hungarian landfills is indisputable; its research is definitely justified. In our paper, we undertake this task based on the periodic drone geodetic surveys of the landfill of a medium-population city in Hungary. After evaluating the results of each survey, the expected date of landfill saturation is determined by us, and possibilities for its further specification are also examined.

GNSS time and frequency transfers through national positioning, navigation and timing infrastructure

Abstract GNSS signals have been a practical time transfer tool to realise a Coordinated Universal Time (UTC) and set civilian clocks around the world with respect to this atomic time standard. UTC time scale is maintained by the International Bureau of Weights and Measurements (BIPM) adjusted to be close to a time scale based on the Earth’s rotation. In Thailand, the official atomic time clocks are maintained by the National Institute of Metrology Thailand (NIMT) to produce UTC(NIMT) and Thailand standard time which is always 7 hours ahead of UTC(NIMT) because of the time zone differences between Greenwich and Bangkok. National Positioning, Navigation and Timing (PNT) infrastructure comprises of GNSS geodetic receivers uniformly distributed to continually observe GNSS signals, mainly for geodetic survey applications both real-time and post-processing services. NIMT is involved in order to provide time link to UTC and to determine the characteristics of GNSS receiver internal clocks; namely, fractional frequency offset and frequency stabilities by applying the GNSS time transfer techniques of common-view algorithms. Monitored time differences with respect to UTC(NIMT) are achieved from selected 4 ground stations in different parts of the country with observations of 21 days in order to determine the frequency stability at 1-day and 7-day modes. GNSS standard log files; in RINEX format, at these receivers are transformed into a time transfer standard format; CGGTTS, used to compute the time differences between two stations, the fractional frequency offset and the frequency stability. Averaged fractional frequency offsets are 2.8 × 10 − 13 Hertz/Hertz 2.8\times {10^{-13}}\hspace{2.38387pt}\text{Hertz/Hertz} and computed Allan deviation is around 1.5 × 10 − 13 Hertz/Hertz 1.5\times {10^{-13}}\hspace{2.38387pt}\text{Hertz/Hertz} for an averaging time of 1 day. The comparison of the national time scale and receiver clock offsets of every receivers in this national GNSS PNT infrastructure could be accomplished through common-view time transfer using GNSS satellites to maintain the time link of geodetic active control points to UTC as well as to determine receiver internal clock characteristics.

Геодезические основы картографии в Европе в XIX веке

Geodetic surveying comprises the determination of locations on and the dimensions of the earth’s surface at a various scales. In the 19th century, its technologies are those of direct measurement of the earth’s surface combined with astronomical observations. Its social context encompasses all those individuals and institutions involved in the creation, preservation, use, and arrangement of knowledge of the earth. In the introductory part of the paper the author mentions several important events in the history of the 19th century geodesy. Geodetic work on determining the size of the Earth by measuring the lengths of the meridian arcs continues in this century. An international surveying organization was established and the international meter convention adopted. Basing on a detailed research of geodetic surveying in Central, Eastern and Southeastern Europe in the 19th century, a part of these surveys is presented that relates to Switzerland, Austro-Hungarian Monarchy, Austria, Hungary, Slovenia and Croatia. Common to all these geodetic surveys is that they were necessary for the development of cartography and were carried out by military institutions. The developed geodetic networks are characterized by the use of different ellipsoids, different prime meridians, different coordinate systems and their origin. In the area under consideration in the 19th century, there were five different ellipsoids in use suggested by Bessel, Bonenberger, Schmidt, Valbeck and Zach. Prime meridians were

Analysis of causes of underground and atmospheric water in basements of the building in operation

The main reasons for the appearance of underground and atmospheric water in the basements of the school building, which has been in operation for more than two years since its commissioning, are considered. The building is three-story, brick, with a basement and attic roof. The building foundation is made in the form of two monolithic reinforced concrete slabs arranged at different elevations (in height) and separated by a deformation joint. Geodetic survey data indicate that the site of the building is located in the lowest part of the courtyard. The engineering and geological structure and hydrogeological features of the construction site, as well as the state of the relief and structural solutions of the yard structures are analyzed. The results of the survey of building structures, observations of the position of the ground water level at the base of the building and atmospheric waters on the courtyard territory are given. Based on the results of the survey, assessment of the ground conditions of construction, observations of the hydrogeological regime, the main reasons for the appearance of underground and atmospheric water in the basement of the operated building were established in the base.

About the approximation of the tunnel lining deformations according to the measurement results

The article deals with the approximation of the displacements of the points of the tunnel lining contour, obtained, for example, by geodetic survey. In the future, the processed data can be used to calculate the internal forces in the tunnel lining, which will help in monitoring the technical condition of the bearing structures of underground structures. In the article, calculation formulas have been obtained that allow using the measured displacements of the reference points to find the displacements of any point of the lining. Displacements are determined by approximating deformations with periodic cubic splines. To determine the coefficients of splines, it is proposed to apply the common least squares method. A method for calculating the weighting coefficients of basic functions for a spline with an arbitrary step of the nodes is presented. As an intermediate result, analytical dependences were obtained between the Cartesian coordinates of the tunnel lining points and the arc length. In this case, the design data on the radii of curvature of the lining sections and the coordinates of the points of section conjugation were used. It is assumed that the data obtained will increase the information content of the control and can be used to monitor its technical condition of underground structures at all stages of its life cycle.

Practical implementation of the use of GNSS RTK technologies for obtaining topographic and geodetic data

This paper analyzes the use of GNSS equipment when conducting topographic surveys. It was revealed that despite the presence of a large number of modern and high-precision GNSS receivers, nowadays, the regulatory and legal framework has established significant restrictions on the use of GNSS equipment when carrying out topographic and geodetic surveys. According to the current legislation, this equipment cannot accurately determine coordinates and heights on the ground. To prove the opposite, a scientific experiment was carried out, as a result of which it was found that modern GNSS receivers can more accurately determine coordinates and heights on the ground than modern total stations and electronic theodolites. Therefore, it is recommended to use the obtained data of the experiment as a basis for making changes to the regulatory framework.

JUSTIFICATION OF THE EXECUTIVITY OF THE SINGLE-FORMAT TECHNOLOGY OF AUTOMATED PROCESSING OF THE RESULTS OF GEODESIC MEASUREMENTS

The expediency of single-format technology of automated processing of geodetic measurements for the needs of the road construction industry is considered. This technology allows you to perform end-to-end automated processing of geodetic measurements with subsequent automated design and transfer the results of one design phase to the next in a single format and a single design environment. Through single-format automated technology for processing geodetic measurements and development of design solutions is to transfer the results of one stage of data processing or development of design solutions to another in one format and one software package. In the event of any corrections to previous results or the development of new solutions at any stage, all changes should be reflected in all parts of the project. This approach will allow the use of a one-time digitally developed highway project at all subsequent stages in the development of overhaul and reconstruction projects, subject to changes in the digital model of the area. The digital model of the terrain and section of the highway constructed in this way can be constantly adjusted and used at the stages of geodetic surveys, design, construction or repair and maintenance until the next geodetic surveys. End-to-end single-format cycle includes: design, technological design, engineering analysis, control programs. This ensures the integrity of the geometry in the transition to each subsequent stage. Providing end-to-end automated automated processing of geodetic measurement results for road repair or construction design tasks can be done by involving software products such as «CREDO», «Topomatic Robur», «Autodesk Civil 3D» and others. The use of single-format end-to-end automated processing of geodetic measurements with the subsequent construction of a digital terrain model will speed up and facilitate the development of design solutions, improve their quality, which in turn improves the quality of roads and man-made structures.

Influences of the heterogeneity of viscoelastic medium on postseismic deformation of the 2008 MW7.9 Wenchuan earthquake

The study of postseismic deformation is important for constraining the viscoelastic properties of the Earth and inverting the post-earthquake process. The levelling survey revealed that the area near Beichuan elevated 5.3 cm about two years after the MW7.9 Wenchuan earthquake (05/12/2008), during which the area underwent significant downward movement. The GPS horizontal displacements showed a non-monotonic variation after the Wenchuan earthquake. In this study, a 3-D viscoelastic finite element model is employed to simulate the coseismic and postseismic deformation of the Wenchuan earthquake. The numerical simulations show that the lateral heterogeneity across the Longmenshan fault plays an important role in the postseismic displacements. The results reveal that the coseismic deformation is not sensitive to the horizontal heterogeneity, but the postseismic deformation is sensitive to it. The postseismic deformation of the horizontally heterogeneous model is generally consistent with the observations of all geodetic surveys, such as GPS, InSAR and levelling, but not for the horizontally homogenous model. We also find that the non-monotonous variation of the postseismic deformation of the Wenchuan earthquake could be explained by a viscoelastic relaxation model with lateral heterogeneous medium across the Longmenshan fault.

Colorado geoid computation experiment: overview and summary

The primary objective of the 1-cm geoid experiment in Colorado (USA) is to compare the numerous geoid computation methods used by different groups around the world. This is intended to lay the foundations for tuning computation methods to achieve the sought after 1-cm accuracy, and also evaluate how this accuracy may be robustly assessed. In this experiment, (quasi)geoid models were computed using the same input data provided by the US National Geodetic Survey (NGS), but using different methodologies. The rugged mountainous study area (730 km $$\times $$ 560 km) in Colorado was chosen so as to accentuate any differences between the methodologies, and to take advantage of newly collected GPS/leveling data of the Geoid Slope Validation Survey 2017 (GSVS17) which are now available to be used as an accurate and independent test dataset. Fourteen groups from fourteen countries submitted a gravimetric geoid and a quasigeoid model in a 1′ $$\times $$ 1′ grid for the study area, as well as geoid heights, height anomalies, and geopotential values at the 223 GSVS17 marks. This paper concentrates on the quasigeoid model comparison and evaluation, while the geopotential value investigations are presented as a separate paper (Sánchez et al. in J Geodesy 95(3):1. https://doi.org/10.1007/s00190-021-01481-0 , 2021). Three comparisons are performed: the area comparison to show the model precision, the comparison with the GSVS17 data to estimate the relative accuracy of the models, and the differential quasigeoid (slope) comparison with GSVS17 to assess the relative accuracy of the height anomalies at different baseline lengths. The results show that the precision of the 1′ × 1′ models over the complete area is about 2 cm, while the accuracy estimates along the GSVS17 profile range from 1.2 cm to 3.4 cm. Considering that the GSVS17 does not pass the roughest terrain, we estimate that the quasigeoid can be computed with an accuracy of ~ 2 cm in Colorado. The slope comparisons show that RMS values of the differences vary from 2 to 8 cm in all baseline lengths. Although the 2-cm precision and 2-cm relative accuracy have been estimated in such a rugged region, the experiment has not reached the 1-cm accuracy goal. At this point, the different accuracy estimates are not a proof of the superiority of one methodology over another because the model precision and accuracy of the GSVS17-derived height anomalies are at a similar level. It appears that the differences are not primarily caused by differences in theory, but that they originate mostly from numerical computations and/or data processing techniques. Consequently, recommendations to improve the model precision toward the 1-cm accuracy are also given in this paper.

The Application of Satellite Navigation System in Deformation Monitoring

Global satellite navigation system has become one of the top technical means in the world. The use of satellite navigation in many fields, such as deformation measurement, civil navigation, search resources, geodetic survey, auxiliary precision engineering monitoring and so on, can play its high precision positioning, all-weather monitoring and other technical characteristics. At the same time, satellite navigation system is combined with modern information technology. Internet technology and so on, which realizes the automatic collection, transmission, processing and analysis of safety monitoring data, and the application efficiency is maximized. The present situation and application of satellite navigation system to monitor the deformation of high-rise buildings are studied in this paper. Nowadays, more and more high-rise buildings in the world have sprung up like bamboo shoots. Therefore, how to realize the satellite navigation system to carry on the all-weather, the high precision, the high efficiency monitoring to the high-rise building, carries on the diagnosis to the dangerous signal in time, timely carries on the forecast to the future possible danger and the timely stop loss, this has the very important realistic significance. By reading the literature, the paper expounds the concepts of satellite navigation system, satellite navigation system and Internet technology in detail. The paper mainly takes the high-rise building scaffold as the object of deformation monitoring, and expounds the advantages and reliability of GPS as high-tech for deformation monitoring of high-rise buildings. Finally, through experimental design, the recognition of GPS technology by comparative method reflects the inestimable position of satellite navigation technology.

Applicability of semi‐pro unmanned aircraft system for rapid archaeological documentation in forested areas

AbstractThis paper tests the applicability of an unmanned aerial system (UAS) in obtaining spatial data from archaeological sites in forested areas. Our case study discusses the remains of the anti‐Turkish fortifications called ‘Turške Šance’—the defensive ditches that are preserved in the area of the Preški vrh (Ravne na Koroškem, Slovenia). Up to 10 fortifications of various shapes and sizes were built in the last quarter of the 15th century. Today, they represent a unique archaeological site. A detailed geodetic survey of the site was performed and compared with results of photogrammetry using the DJI Phantom 4 PRO UAS drone and DJI Phantom camera. Furthermore, official Slovenian LiDAR data of the area were obtained, and archaeologic field surveys, in situ inspections and metal detector scanning were made. The points obtained from the total station were used for 3D modelling and taken as a reference. Drone photogrammetry was performed once per week to compare each point cloud with another using CloudCompare and to the reference one depending on the volume of the tree leaves which was estimated with green leaf index (GLI) and leaf area index (LAI). The increase of the tree leaves volume deteriorates the point cloud obtained with a UAS. The paper analyses how significant this influence is. As expected, the impact grows more severe with the increase in leaf mass from week to week.

Methodological approaches to assessing the stress-strain state of pipelines in cases of their asymmetric load on the sections of overhead crossings

The geodetic surveys results of a number of above-ground pipeline crossings for various purposes in the study of stress-deformed state (SDS) are summarized. It is shown that pipelines are characterized by the process of asymmetric loading, which is manifested in the displacement of the maximum deflection arrow relative to the middle of the span. Methodical approaches to estimation of SDS of pipelines in cases of its asymmetric loading on sections of overpasses are offered. The minimum radius of curvature of the pipeline was chosen as the criterion for SDS assessment. In the first approximation, the curved axis of the pipeline is approximated by an arc of a circle and on the basis of geometric similarity the calculated formula of radius of curvature is obtained. The formula is extended to all cases of asymmetric loading by introducing the dimensionless function y(k) depending on the asymmetry coefficient k. This function y(k) is obtained using the theory of the curved axis of the beam, which is loaded by a concentrated force P, and approximated by a linear dependence. It is analyzed that at symmetrical loading the existing approaches to approximation of the axis of the pipeline by an arc of a circle give the underestimated result in an estimation of the SDS by 34%, and at asymmetric loading this discrepancy increases to 46%. The practical convergence of the results of the minimum radius of curvature with the experimental data is confirmed. The proposed technique is focused on the practical application of the processing of geodetic measurements, as it includes the parameters available for SDS control by geodetic instruments.

PERFORMANCE OF ENGINEERING SURVEYS AS AN INTEGRAL PART OF LAND AND CADASTRE WORKS IN PREPARATION OF LAND PLOTS FOR REGISTRATION IN THE BASE OF THE STATE LAND CADASTER

Performing engineering surveys is a mandatory part of the development of technical documentation on land management. Surveys allow to confirm the accuracy of the performed geodetic or topographic survey. In particular, the accuracy of determining the geodetic coordinates of the turning points of the boundaries of the land, to link the turning points of the boundaries of the land to the geodetic points of the State Geodetic Network of Ukraine. The main purpose of the article is to reflect the main components of engineering surveys as part of land cadastral works in preparation of land for registration in the database of the State Land Cadastre. The coordinate basis for land management is the State Geodetic Reference Coordinate System USK-2000, the geodetic basis for land management – points of the State Geodetic Network 1-3 classes, points of geodetic networks of compaction 4 class, 1 and 2 categories, points of the surveying network. The coordinates of the points of the State Geodetic Network of Ukraine, geodetic networks of condensing and turning points of the boundaries of geospatial objects are determined by rectangular coordinates (x, y) in the Gauss-Krueger projection in the USC-2000 coordinate system or local coordinate systems. related to the USC-2000 coordinate system. The control of the differential field of coordinate corrections when working with the use of RTK technologies is carried out at least at the two nearest points of DGM and GMZ, the coordinates of which are obtained from the administrator of the geodetic data bank. The difference in the values of the coordinates of control points should not exceed 0.1 m in cities of regional importance, 0.2 m - in other cities and towns, 0.3 m - in rural areas and 0.5 m - outside the settlements. Keywords: engineering surveys, State Geodetic Network of Ukraine, land cadastral works, coordinate system, State Land Cadastre.