خيارات البحث
النتائج 1 - 10 من 14
European vertical reference system in Baltic countries
2014
Celms, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Bimane, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Reke, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
At the moment all three Baltic countries – Estonia, Latvia and Lithuania – use Baltic Normal Height System 1977 as a national height system. But the European Union regulations declared the European Vertical Reference System as a national height system. For height transformation there is a transformation formula for each European country. After calculations it is seen that height difference between Baltic Normal Height System 1977 and the European Vertical Reference System depends on point location in the territory (coordinates). This unequal height difference between both height systems will cause unequal height values on border connection points between the Baltic countries.
اظهر المزيد [+] اقل [-]Research of national geodetic network elevations at Eastern part of Latvia
2014
Celms, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ratkevics, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rusins, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
Along with the development of the technological possibilities, the Global Positioning Satellite System (GNSS) is increasingly used in geodetic measurements. Using GNSS, measurements are performed in horizontal plane as well as for point elevation determination. The aim of the article is to demonstrate that the GNSS measurements’ static mode has a high accuracy. To achieve the aim the following objectives were set: 1) to perform global positioning measurements in Class I national leveling network, 2) to calculate the elevation above the sea level, 3) to evaluate the accuracy of performed GNSS measurements. The following research methods were used: static measurement method and analytical method for comparison of the obtained data.
اظهر المزيد [+] اقل [-]Status of the polygonometric network for Kaunas city and region
2014
Kriauciunaite–Neklejonoviene, V., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Rekus, D., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The article presents the research study of the current state and condition of the geodetic base (polygonometric) network for Kaunas city and region as well as the aspects of its compiling. The geodetic base compiled in the post-war years is considered to be of high quality and is used nowadays. The still existing polygonometric network is seldom studied and thus it remains little known. For the purpose of defining the current state of the geodetic base networks, the search for the points in Karmėlava neighbourhood of Kaunas region has been provided. From the total number of 22 points to be searched, five (i.e. 22 percentage) were determined, but only four points (i.e.18 percentage) were appropriate for measurements. The majority of the points has been destroyed during the construction of the residential buildings or roads, or after the reconstruction works. The measurements have been taken by Trimble R6, by RTK method, 10 times for each point. The most reliable value of the measured geodetic points X and Y were defined as well as the errors of the mean square for one measurement and of the average. The results of the survey (100 respondents) showed that the majority of the professionals apply the points of the polygonometric network when making measurements. However, the problems related to a rather rear usage of the network and the aggravated search of the polygonometric points were encountered. A significant part of the professionals suggested the restoration of the polygonometric network.
اظهر المزيد [+] اقل [-]Assessing the impact of wartime conditions on the land surveying industry in Ukraine: Adaptation, challenges, and recovery strategies
2024
Martyn, Andrii | Kolosa, Liudmyla
This article examines the impact of the Russian Federation’s full-scale aggression in Ukraine on the market of land surveying and topographic-geodetic services. The study found that the market for land surveying services decreased by 60–70% due to restrictions in the functioning of the land cadastral system, the introduction of the permit procedure for field geodetic works, and the adaptation of procedures for granting land to citizens during wartime conditions. Technological limitations, such as the use of GNSS networks at the beginning of the war, also played a role in the decline of the industry. The article highlights the prospective needs for land surveying work for post-war reconstruction, including accounting for war damage and mapping affected territories, spatial planning for affected communities, infrastructure restoration, and land reclamation in areas where hostilities took place. The article provides insights into the challenges and opportunities faced by the land surveying industry in Ukraine during wartime conditions and emphasizes the importance of adopting appropriate strategies for recovery and growth. It is shown that despite the war, the development of the industry depends on further digitalization, improvement of the cadastral system, gradual liberalization of access to cadastral geodata, the introduction of special rules for regulating the activities of the surveyor in the territories where hostilities were fought.
اظهر المزيد [+] اقل [-]The structure of geodesic monitoring improvement by horizontal and vertical displacements by applying combination of methods
2023
Vynohradenko, Serhii | Makieieva, Liudmyla | Ryasnyanska, Alona | Kriauciunaite-Neklejonoviene, Vilma | Balevicius, Giedrius
The purpose of the article is to present a combined approach that connects several methods and algorithms to increase the effectiveness of the geodetic network measurement structure for determining horizontal and vertical displacements of engineering objects. Determining the deformation of commercial objects and objects of practical value allows to assess their technical condition. In case of critical changes at such objects, appropriate planning of protection, reconstruction and modernization works is also provided and the negative impact of the environment and weather conditions is indicated. Regardless of the methods used, the measurement of movements and deformations of structures is always preceded by an analysis of the prevailing conditions, as well as a network of geodetic measurement determination and control. These analyses are carried out taking into account manufacturability, economy, and safe use of objects, human safety and environmental protection. The target function was defined, which in this case was chosen as the entropy of the geodesic observation network through the measurement of the parameters vector with true values. Analysing the structure of the control and measurement network and improving its efficiency by the number of necessary observations becomes important for determining reliable changes occurring at the object and the ability to conduct the necessary measurements in the shortest possible time. At the same time, the improved network structure should ensure the redundancy of observations made to match the geodetic network with the modified methods. The optimal number of observations in the geodetic network depended on the observation structure informativeness. During the research, it was noticed that the use of a combined approach will allow selecting only those observations that are the most informative. This will reduce the measurement time without reducing the accuracy of the received movements. The obtained results of the numerical analysis showed the performance of the offered solution for increasing the efficiency of the geodetic network structure formation. It also allows faster and more economical performance of engineering structures geodetic measurements.
اظهر المزيد [+] اقل [-]Analysis of approaches in integration of common solutions of different space geodetic techniques
2017
Khoptar, A., Lviv Polytechnic National Univ. (Ukraine)
The role of space geodetic techniques combination is becoming increasingly important to calculate the geodetic parameters. It has an intention of using the advantages and complementarity of different techniques to achieve the best solution. Estimation of geodetic parameters from observations mainly was done by least squares adjustment within the Gauss - Markov model. The combination can be done at three different levels: observations, normal equations and parameters. This article analyses the differences between the approaches and discusses the possibility of troposphere parameters calculation from a theoretical point of view.
اظهر المزيد [+] اقل [-]Theory and practice improving of mathematical processing of geodetic measurements for land management and cadastre works
2017
Trevoho, I., Lviv Polytechnic National Univ. (Ukraine) | Riabchii, Valeri, National Mining Univ., Dnipropetrovsk (Ukraine) | Riabchii, Vladyslav, National Mining Univ., Dnipropetrovsk (Ukraine)
The article generalizes theoretical and practical addition to the components of mathematical processing of geodetic measurements, which are the basis and used to support work in land management and cadastre. The research identifies general components of mathematical processing of geodetic measurements and components which are primarily used in the field of land management and cadastre. Completed investigation of the theoretical and practical foundations of these components and developed theoretical and practical additions improve the results of mathematical processing of geodetic measurements.
اظهر المزيد [+] اقل [-]Impact of technological changes in land management and geodesy on land surveying higher education in Ukraine
2021
Martyn, A., National Univ. of Life and Environmental Sciences of Ukraine, Kiev (Ukraine) | Hunko, L., National Univ. of Life and Environmental Sciences of Ukraine, Kiev (Ukraine) | Moroz, Yu., National Univ. of Life and Environmental Sciences of Ukraine, Kiev (Ukraine)
The article shows that the rapid technological changes in the field of topographic, geodetic and cadastral activities that have occurred in recent decades, significantly affect the nature and content of work to be performed by future engineers in the field of geodesy and land surveying. The directions of adaptation of the content of geodetic and land surveying education to the needs of the national and world market of engineering services are considered. Global navigation satellite system (GNSS), laser 3D-scanning and operational mapping using unmanned aerial vehicles will have a decisive impact on the development of the industry in the near future. Paper maps are being replaced by multimedia devices that display dynamic map content tailored to a specific consumer. During the study, the student must get acquainted with all the most advanced technologies that will determine the future of the industry in the medium term to be ready for their practical application. A modern university lecture should be designed so that the student can hear only what he or she cannot find on the Internet. The aim of the article is to try to comprehensively generalize and analyse global trends and prospects for the development of topographic and geodetic, cadastral, registration and evaluation activities, as well as to determine on this basis the adaptation of geodetic and land management education to the needs of national and global engineering services.
اظهر المزيد [+] اقل [-]Tendencies of development of local geodetic network in Riga city
2018
Celms, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Parsova, V., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Reke, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Akmentins, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia);Riga City Construction Board (Latvia). Construction Control Dept.
Local geodetic network is very important in harmonic development of city territory. On the base of the local geodetic network, cadastral and topographic surveying works, engineering geodetic works and executive measurements of newly built buildings and engineering networks are carried out. In the territory of Riga, the local geodetic network was started to create in 1880, and in the course of time, as the city expanded, necessity to have wider reference network emerged. In 2005, in the territory of Latvia, network of continuously working base stations LatPos was launched, which ensured completely new trends in execution of measurements and accuracy reached. One year later, base station network EUPOS-RIGA was launched in the territory of Riga. It can be regarded as consistent part of Riga local geodetic network. The purpose of the research was to state, what are differences between historically used coordinates of points of the local geodetic network, and coordinates that are determined by use of real time corrections of LatPos and EUPOS-RIGA base station network. Measurements were made in the territory of Riga in period from December 2016 until April 2017. In the framework of the research, 61 point of the local geodetic network was inspected and in 38 cases GNSS observations in RTK mode were completed. In the research, catalogues of coordinates of polygonometry points of sixties and eighties were used in order to compare what differences of coordinates existed historically. The main conclusion drawn during the research – historical points of the local geodetic network shall not be used for surveying works of any kind before improvement of them and before they comply with requirements of normative acts.
اظهر المزيد [+] اقل [-]Evaluation of the local geodetic network in Jurmala City
2019
Celms, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Reke, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Brinkmanis-Brimanis, M., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Pukite, V., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
In order to evaluate the accuracy of the local geodetic network of Jurmala City, in research, comparison of fortyseven selected polygonometry network point coordinates with the obtained data was made by performing measurements by real time cinematic (RTK) method in LatPos base station system. Points were chosen so in order to cover evenly the entire territory of the city. At present, gradual renewal and improvement of the local geodetic network takes place in Jurmala. In Jurmala City, obtaining of data by GNNS data receivers is encumbered by large density of trees. Therefore the local geodetic network in city has very important role in order to ensure performance of geodetic measurements of high quality in the territory of the city. Aim of the research is to evaluate the accuracy of the local geodetic network of Jurmala City. The following tasks have been set for achieving the aim: research of the given problem, visit of the local geodetic network points, performing control measurements, data processing and analysis.
اظهر المزيد [+] اقل [-]