Preliminarno određivanje točnosti geodetskog monitoringa primjenom metode slobodnog stajališta

In this paper, one of the modern spatial geodetic monitoring method was described: a free station method. This method is effectively used during monitoring of displacements for buildings and constructions under dynamic load. Theoretical prove for rigorous preliminary computing of displacements determination accuracy using free station method was done. The analysis of errors, which influence on the accuracy of spatial monitoring, was presented. It was found out that errors of initial survey network, errors of free station coordinates and errors of spatial monitoring targets coordinates were influencing on the accuracy of measured displacements using the free station method. Using the covariance transformation rules, rigorous formulas for preliminary calculation of displacement determination accuracy were obtained. Experimental calculations were carried out using these rigorous formulas, deploying practical results of spatial geodetic monitoring of transport structure situated in the zone of metro line underground construction. Executed calculations proved that chosen method of spatial deformation monitoring and equipment accuracy conformed the design requirements.U radu je opisana jedna od modernih metoda geodetskog monitoringa: metoda slobodnog stajališta. Ta se metoda učinkovito koristi tijekom monitoringa pomaka na zgradama i građevinama pod dinamičkim opterećenjem. Izveden je teorijski dokaz za temeljito preliminarno računanje točnosti određivanja pomaka koristeći metodu slobodnog stajališta. Prikazana je analiza pogrešaka koje utječu na točnost geodetskog monitoringa. Utvrđeno je da su pogreške inicijalne geodetske mreže, pogreške koordinata slobodnog stajališta i pogreške koordinata meta geodetskog monitoringa utjecale na točnost izmjerenih pomaka primjenom metode slobodnog stajališta. Koristeći pravila transformacije kovarijanci, dobivene su točne formule za preliminarni izračun točnosti određivanja pomaka. Eksperimentalni izračuni provedeni su primjenjujući navedene formule te uz upotrebu praktičnih rezultata geodetskog monitoringa prometnih objekata smještenih u zoni podzemne građevine linije metroa. Provedena računanja su dokazala da su izabrana metoda monitoringa prostornih deformacija i točnost uređaja bili u skladu sa zahtjevima dizajna

Preliminarno određivanje točnosti geodetskog monitoringa primjenom metode slobodnog stajališta

In this paper, one of the modern spatial geodetic monitoring method was described: a free station method. This method is effectively used during monitoring of displacements for buildings and constructions under dynamic load. Theoretical prove for rigorous preliminary computing of displacements determination accuracy using free station method was done. The analysis of errors, which influence on the accuracy of spatial monitoring, was presented. It was found out that errors of initial survey network, errors of free station coordinates and errors of spatial monitoring targets coordinates were influencing on the accuracy of measured displacements using the free station method. Using the covariance transformation rules, rigorous formulas for preliminary calculation of displacement determination accuracy were obtained. Experimental calculations were carried out using these rigorous formulas, deploying practical results of spatial geodetic monitoring of transport structure situated in the zone of metro line underground construction. Executed calculations proved that chosen method of spatial deformation monitoring and equipment accuracy conformed the design requirements.U radu je opisana jedna od modernih metoda geodetskog monitoringa: metoda slobodnog stajališta. Ta se metoda učinkovito koristi tijekom monitoringa pomaka na zgradama i građevinama pod dinamičkim opterećenjem. Izveden je teorijski dokaz za temeljito preliminarno računanje točnosti određivanja pomaka koristeći metodu slobodnog stajališta. Prikazana je analiza pogrešaka koje utječu na točnost geodetskog monitoringa. Utvrđeno je da su pogreške inicijalne geodetske mreže, pogreške koordinata slobodnog stajališta i pogreške koordinata meta geodetskog monitoringa utjecale na točnost izmjerenih pomaka primjenom metode slobodnog stajališta. Koristeći pravila transformacije kovarijanci, dobivene su točne formule za preliminarni izračun točnosti određivanja pomaka. Eksperimentalni izračuni provedeni su primjenjujući navedene formule te uz upotrebu praktičnih rezultata geodetskog monitoringa prometnih objekata smještenih u zoni podzemne građevine linije metroa. Provedena računanja su dokazala da su izabrana metoda monitoringa prostornih deformacija i točnost uređaja bili u skladu sa zahtjevima dizajna

HISTORICAL RETAINING WALLS MONITORING: A CASE STUDY OF DEBOSQUETTE WALL OF KYIV-PECHERSK LAVRA

Geospatial monitoring of historic buildings has a valuable meaning for their restoration and preservation measures. The preparation and accomplishment of such monitoring have their features and cannot be standardized. Therefore, in each particular case, monitoring is carried out for specific requirements and conditions. The paper presents the results of geospatial monitoring for a part of the UNESCO object Kyiv-Pechersk Lavra. The primary subject of geospatial monitoring is a retaining wall known as the Debosquette Wall. The wall was built in the XVIII century and underwent restoration in 2014. A geospatial monitoring system has been established to prevent undesirable damage and displacements. Assigning the necessary observation accuracy for such a complex object is difficult. In the paper, the modern approach to observation accuracy calculation has been suggested and studied. The approach is based on the application of structural mechanics principles. The structural analysis of the Debosquette Wall has been accomplished. The output of the analysis was applied to calculate the required observation accuracy. The geospatial network and monitoring scheme were developed based on the calculated accuracy. The monitoring proceeded for half a year in 2012-2013, was interrupted for one year, and kept on in 2015. The primary stress was made on the horizontal displacements in that these displacements are the primary threats to the wall stability. The in-depth analysis of the monitoring results has been accomplished. It was found that the displacements have stayed within the allowable values. The developed monitoring approach is recommended for similar projects

Geospatial virtual reality for cyberlearning in the field of topographic surveying: Moving towards a cost-effective mobile solution

In spite of the tremendous success in artificial intelligence technology and a high level of automation in geospatial data obtaining processes, there is still a need for topographical field data collection by professional surveyors. Understanding terrain topology and topography is a cognitive skill set that has to be demonstrated by geospatial Subject Matter Experts (SME) for the productive work in the topographic surveying field. For training of the mentioned above skillset, one has to be exposed to the theory and must also practice with surveying instruments in field conditions. The challenge of any surveying/geospatial engineering workforce training is to expose students to field conditions which might be limited due to equipment expenses and meteorological conditions that prevent good data collection. To meet this challenge, the Integrated Geospatial Technology research group is working on a geospatial virtual reality (VR) project which encompasses the following components: (a) immersive visualization of terrain; (b) virtual total station instrument; (c) virtual surveyor with reflector installed on the virtual rod. The application scenario of the technology we are working with has the following stages: (1) student is installing total station on the optimal location; (2) students move virtual surveyor on the sampling points they consider to be important (3) contours are generated and displayed in 3D being superimposed on 3D terrain; (4) accuracy of terrain modeling is observable and measurable by comparing the sampling model with initial one

Bathymetric surveying in Lake Superior: 3D modeling and sonar equipment comparing

This paper represents the overview of hydrographic surveying and different types of modern and traditional surveying equipment, and data acquisition using the traditional single beam sonar system and a modern fully autonomous underwater vehicle (AUV) IVER3. During the study, the data sets were collected using the vehicles of the Great Lake Research Center at Michigan Technological University. This paper presents how to process and edit the bathymetric data on SonarWiz5. Lastly, it compares the accuracy of the two different sonar systems in the different missions and creates 3D models to display and understand the elevations changes. Moreover, the 3D models were created after importing the data sets in the same coordinate system. In this study, the data sets were recorded by two different sensors in the two study locations in the Keweenaw Waterway in Michigan, U.S. between the cities of Houghton and Hancock. The first one equipment is the Lowrance HDS-7 sonar on the surveying boat, and other one is the EdgeTech 2205 sonar on the fully AUV of IVER3. One of the purposes of this study is to explore the sonar post processing programs, which are very important to interpret sonar and bathymetric data, and obtained the same coordinate system of the study areas. During the project, three main processing programs were used. The first one is UnderSee Explorer 2.6, which has been used to process the data sets of Polar SV boat. Secondly, EdgeTech Discover 4600 bathymetric software used EdgeTech 2205 sonar data sets to create bathymetric files that were used in SonarWiz5. Lastly, SonarWiz5 sonar processing software can be used to process the data sets. After the data acquisition and the data process, six profiles from the first study area and the five profiles from the second study are created to compare the data sets and elevations difference. It is shown that single beam sonar might miss some details, such as pipeline and quick elevation changes on seabed when we compare to the side scan sonar of IVER3 because the single side scan sonar can acquire better resolutions to understand the 3D features, such as pipelines, reliefs etc

Structural analysis of monitoring results of long-span roof structures

[EN] The concept of analysis of geodetic monitoring results solely from a geometric point of view is recognized as an obsolete approach. A complex analysis of geodetic measurements (geometric approach) and the structure stress-strain analysis (mechanical approach) allows obtaining the whole picture of any engineering structure displacements. The detailed scheme of the structural analysis of geospatial monitoring results of the long-span roof structures has been given in the presented paper. The results of the geospatial monitoring of the large warehouse have been chosen as a study subject. The structure's roof consists of planar trusses, the main objects of external loads combined with dead loads. According to the complex analysis procedure, the trusses were analyzed using the method of joints with the determination of partial member forces. At the next step, these forces were leveraged in the following order member force–member deformation–node displacement. To obtain the actual displacements of the truss nodes, one has to account for the vertical displacements of the leaning points where the truss touched the column. That step is also being accomplished using the method of joints. Having the actual node displacements, one may compare them with geodetic monitoring results. The comparison results generally allow us to reveal the places with unacceptable displacements and estimate whether they are determined with the necessary accuracy. In this particular case, the final node's displacements were yielded as an output of combined analysis, both geometric and mechanical. That, in turn, lets to acquire the deformation process's genuine parameters. The study results have shown the high efficiency of the presented research methodology.Shults, R. (2023). Structural analysis of monitoring results of long-span roof structures. Editorial Universitat Politècnica de València. 431-438. https://doi.org/10.4995/JISDM2022.2022.1389343143

Investigation of the different weight models in Kalman filter: A case study of GNSS monitoring results

During geodetic monitoring with GNSS technology one of important steps is the correct processing and analysis of the measured displacements. We used the processing method of Kalman filter smoothing algorithm, which allows to evaluate not only displacements, but also the speed, acceleration, and other characteristics of the deformation model. One of the important issues is the calculation of the observations weight matrix in the Kalman filter. Recurrence algorithm of Kalman filtering can calculate and specify the weights during processing. However, the weights obtained in such way do not always exactly correspond to the actual observation accuracy. We established the observations weights based on the accuracy of baseline measurements. In the presented study, we offered and investigated different models of establishing the accuracy of the baselines. The offered models and the processing of the measured displacements were tested on an experimentally geodetic GNSS network. The research results show that despite of different weight models, changing weights up to 2 times do not change Kalman filtering accuracy extremely. The significant improvements for Kalman filtering accuracy for baselines shorter than 10 km were not got. Therefore, for typical GNSS monitoring networks with baseline range 10–15 km, we recommend to use any kind of models. The compulsory condition for getting correct and reliable results is checking results on blunders. For baselines, which are longer than 15 km we propose to use weight model which include baseline standard deviation from network adjustment and corrections for baseline length and its accuracy. Keywords: Kalman filter, Weight model, GNSS, Vertical displacement, Baseline accurac

Methods of Cluster Analysis for Detection of Uniform Displacement Zones of Landslides and Anti-Landslide Structures

The primary goal of landslide monitoring is the development and implementation of appropriate prediction models. Such models will allow forecasting of the anticipated landslide movements and failures. The deployment of these models is only possible by the results of geospatial monitoring. However, the measured displacements of the monitoring targets mostly have different values that may deviate a couple of times for different parts of the observed landslide. Therefore, the correct prediction model can be developed for the points with similar displacements, or in other words, for the points with the same displacement velocities. The grouping of points with similar values is known as clustering or zoning task. Having the groups of similar displacements, it is possible to work out the proper prediction model for each group of displacements and detect the probable blunders in the measurements. The paper outlines the results of geospatial monitoring for landslide and anti-landslide structures carried out for small-scale landslide and a system of retaining walls in Kyiv, Ukraine. The efficiency of cluster analysis for uniform displacement zone identification has been studied by the results of geospatial monitoring. The basic principles and ideas of cluster analysis and clustering methods have been given. The different clustering methods have been examined. Each clustering method's efficiency has been estimated by distance determination methods and similarity measures. The quantitative analysis of the considered clustering methods was checked by evaluation analysis. The most reliable results in a line of the study have demonstrated centroid clustering and furthest neighbor clustering. The determined similarity measures for those two methods were almost the same

STRATEGIES OF GNSS PROCESSING AND MEASURING UNDER VARIOUS OPERATIONAL CONDITIONS

Purpose. GNSS technology is one of the key elements of maintenance of the mining works. Mostly, the GNSS observations in mining regions are accomplished under adverse surveying conditions. The presented paper is aimed at studying the problem of GNSS accuracy under various adverse operational conditions that may encounter during surveying works in deposit fields and downgrade the GNSS accuracy. Methodology. Despite the well-defined problem of GNSS accuracy, each year, new receiver models and software versions come into use, which in turn, needs a more profound analysis of their reliability, accuracy, and efficiency. This study provides relevant information about the static tests that were executed in the canopy, multipath, and open environments to assess the performance of the user segment from different manufacturers. The equipment of three manufactures was tested: Leica, Trimble, and Javad. The test results for two satellite systems, GPS and GLONASS, are presented. Findings. The obtained results can be generalized to the following outputs. Trimble performed the best on the canopy site in terms of position quality and fix solution. Javad had the best agreement for horizontal, height, and 3D solutions between dual and single frequency processing on the multipath site. On the open spot, Leica’s horizontal solution between dual and single frequency processing was the most consistent. It is challenging to state which receiver performed better in the vegetation cover. Originality. The study aims to develop a general procedure to estimate the accuracy of different GNSS processing strategies under different environments. Practical value. The given research has a strong hands-on background insofar as the principal stress is made on field measurements. The research results can be employed to refine the GNSS surveying workflow for open-pit mines

Impact of Landscape Factors on Automobile Road Deformation Patterns—A Case Study of the Almaty Mountain Road

The geography of Kazakhstan is characterized by a diverse landscape and a small population. Therefore, certain automobile roads pass through unpopulated mountain regions, where physical road diagnostics are rare or almost absent, while landscape factors continue to affect the road. However, modern geo-information approaches and remote sensing could effectively provide the road diagnostics necessary to make timely control decisions regarding a road’s design, construction, and maintenance. To justify this assumption, we researched the deformation of a mountain road near Almaty city. Open access satellite images of and meteorological archival data for the region were processed. The resulting data were compared to validate the road’s deformation triggers. Extreme weather conditions’ impacts could be identified via road destruction (nearly 40 m longitudinal cracks, 15 m short transversal cracks, and two crack networks along a 50 m road section). The remotely sensed parameters (vertical displacement velocity, slope exposure, dissections, topographic wetness index, aspect, solar radiation, SAVI, and snow melting) show the complexity of triggers of extensive road deformations. The article focuses only on open access data from remote sensing images and meteorological archives. All the resulting data are available and open for all interested parties to use