Geodetic Methods Research Articles

РОЛЬ ГЕОДЕЗІЇ В МОНІТОРИНГУ ГЕОЛОГІЧНИХ ПРОЦЕСІВ ТА ПРИРОДНИХ КАТАСТРОФ ДЛЯ ПОПЕРЕДЖЕННЯ НЕГАТИВНИХ НАСЛІДКІВ

The purpose of the study is to analyze the contribution of geodetic methods and technologies to the detection, assessment and monitoring of geological processes and natural disasters in order to minimize their dangerous consequences for society and the environment. Research methodology. remote sensing of the Earth, the use of satellite images and aerial photography to collect data on geological processes and the state of the environment. Method of geodetic monitoring. tracking changes in the position of objects over time, which allows detecting soil micromovements, potential landslides and other deformations. GIS technologies (geoinformation systems). Integrating and analyzing geodata to model geological processes and natural disasters, creating thematic maps that can display potential risks and assist in response planning. The results. The task of monitoring geological changes and natural disasters using cartographic methods designed to work with many users has been set and solved, significantly increasing the level of safety and prompt response to emergency events. An important aspect in the implementation of geodetic observations is the use of an integrated approach that includes field research, geodetic analysis and remote sensing data. This ensures higher accuracy and efficiency of monitoring. Scientific novelty. The research focuses on identifying effective approaches to the collection, processing and analysis of spatial data that can be used for timely prediction and prevention of catastrophic events, as well as for emergency response planning. The developed adapted model of risk assessment of natural emergency situations, which is based on the analysis of terrain conditions at various times, allows to increase the accuracy of risk assessments. Practical significance. The use of remote monitoring methods ensures prompt receipt of information and the possibility of taking measures for nature protection in a timely manner. The conceptual model made it possible to identify the factors of man-made influence, assess the condition of soils and vegetation, as well as perform a cartographic analysis of disturbed lands in order to develop measures for their restoration. The created thematic maps of the dynamics of disturbed lands serve as a basis for making management decisions aimed at systematic restoration and reduction of negative man-made impacts, opening up new perspectives for the use of interactive technologies in geodesy.

Monitoring of deformation processes during scientific and technical support of construction

With the scientific and technical support of construction, reconstruction of buildings, structures and unique objects, the issue of assessing the development of deformation processes in newly erected elements, in buildings of surrounding buildings, underground utilities falling into the zone of influence of construction and transport infrastructure facilities is very acute. This task is now being successfully solved by combined methods using traditional geodetic methods and laser scanning using high-precision total stations with the ability to scan.

The Role of Geodesy in High Dams Structural Health Monitoring

Structural health monitoring is a synthesis of geodetic and civil engineering methods of measuring, processing and analyzing data. All constructed buildings are subjected to displacements and deformations that can cause damage or even demolition of the building, which endangers people's lives and causes great material damage. Geodesy plays an important role in the technical monitoring of objects, but this fact does not diminish the importance of physical methods of monitoring, nor can it be argued that one method is more important than another. Each of the above-mentioned methods used for technical monitoring of high dams has its significance and only the joint application of all methods can provide an adequate description of the behaviour of the objects due to the influence of various external and internal factors. This paper will describe the history of high dams monitoring, the role of geodesy in monitoring, current trends, legal frameworks governing the monitoring, and the situation in education regarding this area of geodesy.

Комплексный мониторинг геологической среды в пределах горного отвода строящегося тоннеля

Purpose: To consider the example of the implementation of integrated monitoring based on various information collection and analysis on soil environment movements for further prognosis on massif state and timely corrections of construction decisions. To establish sequence and rhythm of monitoring implementation stages for to obtain timely information on soil massif state. To reveal possible ways of statistical processing of observation results for to ensure deformation development prediction reliability. Methods: No-touch registration method for electromagnetic emission, ground penetrating radar method, seismic-acoustics method, geodetic method, strain gauge method, statistical methods. Results: Possibility to embody deformation complex monitoring on certain example has been studied. Possible sequence of monitoring stages with the use of modern methods and technologies has been described. It has been shown that the collection of data on soil massif state from various sources makes it possible to make reliable conclusions on mining operation safety and to verify them by using statistical analysis methods. The results of real observations of deformations in the limits of mining allotment have been considered. Recommendations are given on observation organization during flank process activation. It has been described the possibility of deformation monitoring organization with complex use of various means for measurement such as inclinometric probes, high precision levels, electronic tacheometers, load cells. Geodetic monitoring (geodetic measurements) of deformations during tunnel construction should be carried out. The paper considers the need to project and create geodetic monitoring planned-altitude networks serving as a base to make observations with required accuracy on offset of construction’s structures and objects surrounding the construction. Practical significance: The results can be used in job organization to monitor offsets in excavation outputs, day surface (surrounding buildings) deformations, in the design of observation stations.

Geodynamic monitoring at the GS RAS: Current state and development prospects

Modern trends in geosciences includes numerical modeling based on vast amounts of direct earth’s surface measurements. A significant increase in the accuracy, detail and scale of the aforementioned measurements in recent decades is based on the active development of space and satellite geodetic methods, as well as the creation of dense observation networks. GS RAS is one of the pioneers in the development of geodynamic monitoring systems based on the usage of satellite geodetic data on the territory of the Russian Federation. The goal of maintaining the leadership position of the GS RAS in the field of geodynamic monitoring emphasizes the development of modern satellite geodetic methods in conditions of limited resources and the need to develop import-substituting technologies. The article considers the existing scientific and methodological groundwork created in the geodynamic monitoring sector of the GS RAS, and formulates promising development areas of the geodynamic monitoring subsystem.

ВПЛИВ НА ВАРТІСТЬ ЗЕМЕЛЬНИХ ДІЛЯНОК ПОХИБОК ПОЛОЖЕННЯ МЕЖ ОТРИМАНИХ ІЗ ВИКОРИСТАННЯМ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ

Purpose. The study of the effect of errors in the position of landmarks obtained using unmanned aerial vehicles, on the value of real estate. Aerospace for several decades is an effective tool for conducting geodetic works, geophysical studies and conducting various types of monitoring, but such methods are not used to assess the real estate. Modern technologies for the creation of topographical and cadastral plans are based precisely on the use of digital aerosol materials. However, the cost of using airplanes and helicopters for local large-scale take-off is on an order of magnitude higher and therefore an alternative solution is the use of UAVs. Methodology. Unmanned aerial vehicles (UAVs) are most often used as a cheap alternative to conventional airplanes from airplanes, helicopters, telescopes and satellite (satellite) takeoffs. In addition to significant cost-effectiveness (cheaper by ten times), UAVs have additional privileges, namely: low altitude, point-and-shoot, mobility, environmental cleanliness of flights. Land management works are mostly carried out unsystematically and without reliable control, and therefore the application of usual geodetic methods and measurement results does not allow obtaining the required precision of the coordinates of the points, boundaries and the film basis. All this leads to the problems of combining the boundaries of adjoining areas due to the use of poor-quality cadastral information in databases that were formed over a significant period of time by the regional centers of the SLC. Results. The use of UAVs proves the importance of them to perform valuation works, which will increase the accuracy of the determination of the coordinates of the boundaries of real estate and significantly accelerate the evaluation procedure. It is established that for large settlements, the accuracy of the determination of the coordinates should be significantly increased, since the cost of real estate in these settlements is quite large and, accordingly, the errors in determining the coordinates of real estate objects lead to errors in the cost of real estate objects of the settlement, which is legally unacceptable and therefore For very large cities it is expedient to create shots at low altitudes and gradually increase the accuracy of photographing the terrain. Scientific novelty and practical significance. The importance of using UAVs for assessing the value of real estate objects has been proved, as the resulting calculations result in average square errors in the value of 1 sq. M of real estate, amounting to less than 0.3% of its total value. The practical significance of the use of UAVs lies in the existence of additional advantages over traditional shooting methods, namely the possibility of obtaining a super-distinction (one and ten centimeters) in the terrain; the detailed removal of small objects and small areas where it is completely unprofitable or technically impossible to do in other ways, for example, in urban development.

Applying the Geodetic Adjustment Method for Positioning in Relation to the Swarm Leader of Underwater Vehicles Based on Course, Speed, and Distance Measurements

The research consisted of simulating the movement of a single vehicle in relation to the swarm leader on a square-shaped path, taking into account measurement errors characteristic of typical cheap navigation devices and the hydroacoustic system. The research showed that these methods allow for estimating position coordinates with an accuracy of about 0.5 m (RMS) in the case of a calibrated navigation system and about 3.6 m (RMS) in the case of a non-calibrated navigation system. It also showed that it can provide a higher accuracy of estimating position coordinates in terms of abeam angles of the swarm leader (relative bearing equal to approximately ±90°), as well as while ensuring minimizing systematic errors values and proper estimation of mean errors values concerning course and speed measurements.

Increased Mass Loss of Glaciers in the Sawir Mountains of Central Asia between 1959 and 2021

Glacier mass balance can be regarded as a major direct index of climate variations. In this paper, a geodetic method was used to evaluate the mass balance of Sawir glaciers based on topographic map DEM (Digital Elevation Model), SRTM 30 m DEM, ASTER 30 m DEM, and Sentinel-1 Synthetic Aperture Radar 10 m DEM between 1959–2021, in order to explore the response to climatic alterations. In the case of Muz Taw glacier, the first comprehensive dataset concerning mass-balance readings for the 2014–2021 period was provided based on the eight-year consecutive field measurements. The glaciological average mass balance reached –883.4 ± 130 mm a–1 during this period. The geodetic mass balance for all glaciers of the Sawir Mountain range was −0.43 ± 0.12 m w. e. a−1 between 1959 and 2000, and accelerated to −0.56 ± 0.13 m w. e. a−1 between 2000 and 2021. A comparison of field measurements and remote-sensing approaches for determining the Muz Taw glacier’s mass balance between 2014–2021 proves the feasibility of the remote-sensing approach, which involves mass-balance monitoring based on DEMdata. In addition, our findings support the contention that air temperature is the dominant factor for accelerated glacier mass loss and surface elevation change.

The Impact of Modern Topo-Geodetic Technologies on Positioning Techniques


 The field of constructions has evolved extraordinarily in terms of measurement techniques, requiring increasing accuracy. This has led to the creation of new specific technologies, and implicitly measuring instruments. The range of classical geodetic measuring instruments has been completed with new high precision instruments, even in the field of physics or machine building. The use of geodetic measurement methods in the field of Engineering Topographic Measurement Techniques involves, in addition to ensuring precision requirements, the choice of appropriate devices and technologies. This choice is imposed both by the previous precision calculations, starting from a maximum permissible deviation given, and by the knowledge of the execution and assembly technologies. The purpose of this paper was to study the effect and also the impact that new technologies had on the main measurement activities, and of course on measurement techniques. This review article summarizes, analyzes and discusses the current state of primary research in terms of the impact of current or developing technologies on geodetic techniques. The global corpus of primary research is growing at an unprecedented rate. It is difficult for most researchers to grasp the state of the art of a topic. A vast number of bibliographic references were taken into account, on which analyzes were performed.

A METHOD FOR THE STAKE-OUT OF THE SEATS IN THE CONFERENCE ROOM

Before the application, the coordinates of the circle shaped seat places that will be applied in indoor space can be obtained by the help of common points determined in numerical project model formed in a local coordinate system. Practically, the coordinates of the points in the digital project model can be also obtained numerically by using the coordinates of the common points. However, converting to numerals manually, the factors such as the support quality of the project, exhaustion of the operator, hand tremble and screen resolution influence the sensitivity of the conversion to numerals. Errors made during the conversion negatively affect the coordinates of the points. The most suitable method not to make errors is the calculation of coordinates of the points in the project model by geodetic method. In this project, the calculation of the coordinates of the seat midpoints placed on the curves in a closed area, benefited from the corner point coordinates of the seats in the indoor space obtained from geodetic measurement in a local coordinate system before the application and benefited from the data of the other points of the indoor space are explained. Furthermore, the ground application of the midpoints of the seats on each curve row is explained. The accuracy of the stake-out of seats in the conference room is obtained between 1 and 2 cm.

Glacier-wide seasonal and annual geodetic mass balances from Pléiades stereo images: application to the Glacier d'Argentière, French Alps

AbstractThe increased availability of high-resolution and high-quality digital elevation models (DEMs) allows for the investigation of small-scale glaciological changes and improved precision in geodetic mass-balance estimates. However, high precision and careful methodological choices are required to retrieve glacier-wide mass changes at annual to seasonal time scales. Here, we used a 7-year time series of 12 DEMs of the Glacier d'Argentière, in the French Alps, derived from the Pléiades optical satellites to assess the ability of sub-metre stereoscopic satellite images to retrieve annual-to-seasonal mass balances. We found good agreement between the five annual and the four winter mass-balance values estimated using a geodetic method and those of in situ glaciological measurements: mean values via the geodetic method are −0.66 m w.e. and 1.47 m w.e. for annual and winter balances, respectively; mean absolute discrepancies are 0.25 m w.e. (annual) and 0.36 m w.e. (winter). Our study identified three main limitations of this methodology: (i) the intrinsic DEM precision; (ii) the lack of control over the satellite acquisition dates; and (iii) the density assumption. The consistency between the methods demonstrates the potential of short time-scale glacier mass-balance monitoring using very high-resolution satellite images.

Three-dimensional displacement field of the 2010 Mw 8.8 Maule earthquake from GPS and InSAR data with the improved ESISTEM-VCE method

The 2010 Mw 8.8 Maule earthquake occurred offshore central Chile and ruptured ∼500 km along the megathrust fault resulting from the oceanic Nazca plate subducting beneath the continental South American plate. The Maule earthquake produced remnant crustal displacements captured by a vast set of geodetic observations. However, given the nature of the observational techniques, it is challenging to extract its accurate three-dimensional coseismic deformation field with high spatial resolution. In this study, we modified the extended simultaneous and integrated strain tensor estimation from geodetic and satellite deformation measurements (ESISTEM) method with variance component estimation algorithm (ESISTEM-VCE) to retrieve the three-dimensional surface displacement field of this event by integrating the interferometric synthetic aperture radar (InSAR) and global positioning system (GPS) measurements. The ESISTEM-VCE method accounts for the spatial correlation of surface displacement among the adjacent points and determine the accurate weight ratios for different data sets, but also uses the uncertainties of GPS data and considers the different spatial scales from the different datasets. In the simulation experiments, the RMSEs of the ESISTEM-VCE method are smaller than those of the ESISTEM and ESISTEM-VCE (same d0) methods, and the improvements of 97.1%, 3.9%, and 84% are achieved in the east-west, north-south, and vertical components, respectively. Then, we apply the proposed methodology to the 2010 Mw 8.8 Maule earthquake, to obtain a three-dimensional displacement field that could provide fine deformation information. In the east-west component, the significant deformation is in the north of the epicenter, closed to the Constitución, with a maximum westward displacement of 495.5 cm. The displacement in the north-south component is relatively small compared to that in the east-west component. The maximum uplift reaches 211.8 cm, located at the southwest of the Concepción. Finally, the derived vertical displacements are also compared with field investigations, indicating that the ESISTEM-VCE method can obtain more accurate weight of different datasets and perform better than the ESISTEM method. The results highlight that the earthquake ruptured along the NE-SW direction, with a dominant thrust and a relatively small component of right-lateral strike-slip, coinciding with the characteristics of subduction and right-lateral shear. The experiments with the simulated and real data suggest that the improved ESISTEM-VCE method in this study is feasible and effective.

Establishment of deformation and subsidence monitoring baseline in the coastal environment: A case study of University of Lagos

Deformation and subsidence measurements are very vital for stability of structures and buildings. Deformation and subsidence monitoring are easily carried out with the aid of established baselines. This study focuses on the establishment of baseline for monitoring deformation and subsidence within university of Lagos. Geodetic method of control establishment was adopted, where five (5) control stations were established on stable grounds across the university of Lagos main campus with Differential GPS observation carried out on them and data obtained were processed and analysed statistically. The result of the findings shows that the baseline established is very reliable, given that the vertical controls have their relative redundancy number rij ranging between 0.1<rij<1.0 and the standard deviations ranges from 0.002 to 0.005. Also, the relative precision of the established baselines fell within the range of 7.36e-06ppm-2.54e-05ppm. From the findings of this research, deformation and subsidence studies can be reliably monitored within the University of Lagos and its environ using the baseline established through this research in order to safeguard lives and properties – including high rise structures within the university’s main campus.

Surface mass balance monitoring of the peripheral glaciers of the Antarctic Peninsula in the context of regional climate change

AbstractDuring the second half of the 20th century, the Antarctic Peninsula region has undergone a long and sustained warming period, followed by a shorter but also sustained cooling period, and then a very recent return to warming conditions. All of these have profoundly impacted the glaciers peripheral to the Antarctic Peninsula. This paper focuses on the analysis of the surface mass balance monitoring of such glaciers by the glaciological method, complemented by the analysis of mass-balance estimates by geodetic methods, as well as frontal ablation estimates. We aim to summarize the current knowledge and outline the main challenges faced by investigating the mass balance of such peripheral glaciers and their current contribution to sea-level rise.

Novel Integration of Geodetic and Geologic Methods for High‐Resolution Monitoring of Subsidence in the Mississippi Delta

AbstractLand‐surface subsidence is a major contributor to land loss in many river deltas. New approaches yielding high‐resolution data are needed to parse the relevant driving forces. In 2016, we established a novel “subsidence superstation” ∼2 km from the Mississippi River in coastal Louisiana (USA) to measure compaction in a global reference frame as a function of depth in Holocene sediments and deeper subsidence. The site features three borehole optical fiber strainmeters to obtain continuous records of displacement between ∼1.3 m below the surface and depths of ∼11, 25, and 38 m. These data are complemented by an adjacent station providing hydrologic data and near‐surface compaction. We also installed three GPS antennas, one of which is mounted to a rod cemented into the Pleistocene basement. A core from one of the boreholes provides insight into the sediment properties of the entire Holocene succession. Five years of records reveal the compaction rate in the material between 1.3 and 38 m is likely less than 0.25 mm/yr. The GPS records yield a subsidence rate of 2.5 mm/yr regardless of the depth of the anchor, thus corroborating the low compaction rates observed by the strainmeters. The new instrumental records show that current subsidence at this location is governed mostly by deformation of the Pleistocene or underlying strata rather than compaction of Holocene material, with the exception of the uppermost meter. The methodology represents an important new approach to mapping subsidence rates at varying depths, providing insight into the mechanisms governing delta subsidence.

Halving of Swiss glacier volume since 1931 observed from terrestrial image photogrammetry

Abstract. The monitoring of glaciers in Switzerland has a long tradition, yet glacier changes during the 20th century are only known through sparse observations. Here, we estimate a halving of Swiss glacier volumes between 1931 and 2016 by mapping historical glacier elevation changes at high resolution. Our analysis relies on a terrestrial image archive known as TerrA, which covers about 86 % of the Swiss glacierised area with 21 703 images acquired during the period 1916–1947 (with a median date of 1931). We developed a semi-automated workflow to generate digital elevation models (DEMs) from these images, resulting in a 45 % total glacier coverage. Using the geodetic method, we estimate a Swiss-wide glacier mass balance of −0.52 ± 0.09 m w.e. a−1 between 1931 and 2016. This equates to a 51.5 ± 8.0 % loss in glacier volume. We find that low-elevation, high-debris-cover, and gently sloping glacier termini are conducive to particularly high mass losses. In addition to these glacier-specific, quasi-centennial elevation changes, we present a new inventory of glacier outlines with known timestamps and complete attributes from around 1931. The fragmented spatial coverage and temporal heterogeneity of the TerrA archive are the largest sources of uncertainty in our glacier-specific estimates, reaching up to 0.50 m w.e. a−1. We suggest that the high-resolution mapping of historical surface elevations could also unlock great potential for research fields other than glaciology.

Creation of the Point Cloud and the 3D Model for the Above-Ground Infrastructure in the City of Chisinau by Modern Geodetic Methods

This study proves the effectiveness of laser scanning and the importance of its application in the point cloud creation and 3D model building, designing thus a model aiming to reorganize the above-ground infrastructure of the "Petrom" Oil Base in Chisinau. A comparative study of combined terrestrial laser scanning and aerial laser scanning methods will be presented, managing to offer a high-quality final product, ensuring a certain level of precision for the redevelopment and reconstruction of municipal networks. The terrestrial laser scan of the entire object was performed from 53 stations, and 604 photogrammetric images were taken during the airborne laser scan. Following the data processing through certain specialized software, the 3D model was created, with an accurate estimate of 0.0015 m - 0.002 m.

Geodetic monitoring of geotechnical structures displacements: a case study of Radiowo landfill site in Warsaw

Geodetic monitoring of deformation has an important role in ensuring the safety of geotechnical objects by monitoring of not exceeding the critical states defined for slope stability and monitoring the uniformity of the object settlement process. A special case of such objects are landfills built of various anthropogenic materials. Heterogeneous building material causes increased values of displacements in relation to other geotechnical objects and requires that measurement works be carried out throughout the entire life cycle of the landfill: both in the exploitation phase, during the reclamation period and in the post-exploitation phase. This study presents the methodology of geodetic measurements of deformation of geotechnical objects on the example of the Radiowo landfill and the results of this type of measurements carried out for 30 years on this object. The analysis of the literature has also shown that, in addition to the commonly used geodetic methods, it is possible to use modern measurement methods such as laser scanning and photogrammetry, which are more and more often successfully used in the measurement of this type of structures. These methods can be an interesting alternative in measuring the displacement of landfills or constitute their perfect supplement.

Geospatial Information Research: State of the Art, Case Studies and Future Perspectives.

Geospatial information science (GI science) is concerned with the development and application of geodetic and information science methods for modeling, acquiring, sharing, managing, exploring, analyzing, synthesizing, visualizing, and evaluating data on spatio-temporal phenomena related to the Earth. As an interdisciplinary scientific discipline, it focuses on developing and adapting information technologies to understand processes on the Earth and human-place interactions, to detect and predict trends and patterns in the observed data, and to support decision making. The authors – members of DGK, the Geoinformatics division, as part of the Committee on Geodesy of the Bavarian Academy of Sciences and Humanities, representing geodetic research and university teaching in Germany – have prepared this paper as a means to point out future research questions and directions in geospatial information science. For the different facets of geospatial information science, the state of art is presented and underlined with mostly own case studies. The paper thus illustrates which contributions the German GI community makes and which research perspectives arise in geospatial information science. The paper further demonstrates that GI science, with its expertise in data acquisition and interpretation, information modeling and management, integration, decision support, visualization, and dissemination, can help solve many of the grand challenges facing society today and in the future.

The West Kunlun Glacier Anomaly and Its Response to Climate Forcing during 2002–2020

Research into glacial mass change in West Kunlun (WK) has been sufficient, but most of the existing studies were based on geodetic methods, which are not suitable for specific health state analyses of each glacier. In this paper, we utilize Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery, applying the continuity equation to obtain altitudinal specific mass balance (SMB) for 615 glaciers (>2 km2) during 2002–2011, 2011–2020, and 2002–2020 to research glacial health and its response to climatic forcing. The results show dissimilar glacier SMB patterns between 2002–2011 (0.10 ± 0.14 m w.e. a−1), 2011–2020 (–0.12 ± 0.14 m w.e. a−1) and 2002–2020 (−0.01 ± 0.07 m w.e. a−1). Additionally, the glacier equilibrium line altitude (ELA) in WK was 5788 m, 5744 m, and 5786 m, respectively, and the corresponding accumulation area ratios (AARs) were 0.59, 0.62, and 0.58, during 2002–2011, 2011–2020, and 2002–2020, respectively. Regarding glacier response, compared with the ordinary-least-square (OLS) model, the artificial neural network (ANN) model revealed a respectively less and more sensitive glacier SMB response to extreme negative and positive summer skin temperatures. In addition, the ANN model indicated that the glacier ELA was less sensitive when the integrated water vapor transport (IVT) change exceeded 0.7 kg m−1s−1. Moreover, compared with IVT (−121.57 m/kg m−1s−1), glacier ELA shifts were chiefly dominated by summer skin temperature (+154.66 m/℃) in the last two decades. From 2002–2011 and 2011–2020, glacier SMB was more susceptible to summer skin temperature (−0.38 m w.e./℃ and −0.16 m w.e./℃, respectively), while during 2002–2020, it was more influenced by IVT (0.45 m w.e./kg m−1s−1). In contrast with eastern WK, glaciers in western WK were healthier, although mitigation measures are still needed to safeguard glacier health and prevent possible natural hazards in this region. Finally, we believe that the inconsistent change between glacier SMB and ELAs from 2002–2020 was connected with ice rheology and that the combined effects of skin temperature and IVT can explain the WK glacier anomaly.