Academic literature on the topic 'Local Geodetic Network'

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.

In order to evaluate the accuracy of the local geodetic network of Jurmala City, in research, comparison of forty-seven 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. The linear discrepancy of coordinates obtained in measurements varies from 0.016 m to 0.259 m, mean linear discrepancy in the measured points is fixed 0.110 m. Discrepancy of plane coordinates in different regions of Jurmala is not even. It is rather even within approximate boundaries of the determined regions, this is indicated by different directions of offset vectors, which in eastern part of the city are pointed mainly in NW direction, in central part directions are pointed in W direction, but in the western part of the city pointed in NE direction. Concerning heights, only for 3 of measured points discrepancy exceeds 0.05 m error and there are no connection concerning some specific region. 15% of the measured points of the local geodetic network are with appropriate accuracy of plane coordinates. The linear discrepancy of plane coordinates for points of the local geodetic network, which are measured by RTK method and compared with data from the improved network is 0.024 (m), which indicates the high accuracy of RTK method in measurement data. 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.

Ghana’s local geodetic reference network is based on the War Office 1926 ellipsoid with data in latitude, longitude and orthometric height without the existence of ellipsoidal height. This situation makes it difficult to apply the standard forward transformation equation for direct conversion of curvilinear geodetic coordinates to its associated cartesian coordinates (X, Y, Z) in the Ghana local geodetic reference network. In order to overcome such a challenge, researchers resort to various techniques to obtain the ellipsoidal height for a local geodetic network. Therefore, this paper evaluates, compares, and discusses different methods for estimating ellipsoidal height for a local geodetic network. The investigated methods are the Abridged Molodensky transformation model, Earth Gravitational Model, and the Orthometric Height approach. To evaluate these methods, their estimated local ellipsoidal height values were implemented in the seven-parameter similarity transformation model of Bursa-Wolf. The performance of each of the methods was assessed based on statistical indicators of Mean Square Error (MSE), Mean Absolute Error (MAE), Horizontal Position Error (HE) and Standard Deviation (SD). The statistical findings revealed that, the Abridged Molodensky model produced more reliable transformation results compared with the other methods. It can be concluded that for Ghana’s local geodetic network, the most practicable method for estimating ellipsoidal height is the Abridged Molodensky transformation model. Keywords: Abridged Molodensky Model, Earth Gravitational Model, Orthometric Height, Geodetic Network

The implementation of local geodetic networks for georeferencing of rural properties has become a requirement after publication of the Georeferencing Technical Standard by INCRA. According to this standard, the maximum distance of baselines to GNSS L1 receivers is of 20 km. Besides the length of the baseline, the geometry and the number of geodetic control stations are other factors to be considered in the implementation of geodetic networks. Thus, this research aimed to examine the influence of baseline lengths higher than the regulated limit of 20 km, the geometry and the number of control stations on quality of local geodetic networks for georeferencing, and also to demonstrate the importance of using specific tests to evaluate the solution of ambiguities and on the quality of the adjustment. The results indicated that the increasing number of control stations has improved the quality of the network, the geometry has not influenced on the quality and the baseline length has influenced on the quality; however, lengths higher than 20 km has not interrupted the implementation, with GPS L1 receiver, of the local geodetic network for the purpose of georeferencing. Also, the use of different statistical tests, both for the evaluation of the resolution of ambiguities and for the adjustment, have enabled greater clearness in analyzing the results, which allow that unsuitable observations may be eliminated.

Increasing the speed of trains along railroad tracks and the development of satellite geodetic technologies put forward new requirements for the production of the engineering survey at the rail transport facilities. Ensuring the safety of high-speed traffic is directly related to the accuracy of determining the coordinates and heights of the reference geodetic networks created for the design, construction, reconstruction and operation of railways. A large length of Railways in Russia requires solving a number of problems in the conditions of increasing the accuracy of determining the coordinates. High-speed route crosses several regions with its own local coordinate systems. Simplify the design and cadastral works and reduce to minimum linear distortions when performing geodetic measurements, allows the creation of a local coordinate system, unified for the entire route. The technology of creating a unified local coordinate system for linear objects passing through several 6-degree zones in the projection of GaussKruger and objects located at an angle to the axial Meridian is considered on the example of the railway Moscow — Saint-Petersburg — Vyborg. At the basis of a unified local system of the object, it is proposed to use an oblique cylindrical cartographic projection. Implemented a coordinate system in the form of the software, allowing to perform transformations between the local system, the world and state coordinate systems. The paper also considers the practical experience of creating a high-precision geodetic reference network for a high-speed railway traffic route, which can be used for various linear engineering structures. The created frame network can serve as a geodetic base for performing laser scanning, monitoring facilities, creating geoinformation systems and solving other problems that arise during the operation of an engineering facility.

Abstract: National Geodesic Network of WGS-84 system was founded in the territory of the Republic of Armenia from 2002 to 2007, which includes zero, first, and second class 1115 stations and there were other 229 State Geodesic Triangular Network stations. The observation at these stations has been done by GPS system. Each of the above mentioned stations covers on the average 27 square kilometers of the territory of Armenia. The data obtained during GPS observations have become the foundation for creating local quasi-geoid models and obtaining differences of heights (geoid wave value) of normal and WGS-84 ellipsoid surfaces. On the basis of gravimetric data a quasi-geoid model has been computed and developed. To creat the model coordinates of four geodetic satations encompassing the area of the Republic of Armenia have been used. To get the digital model of the selected area was diveded into five-minute sections by latitude and longitude and then coordinates of geodetic points have been taken. The above mentioned points were recalculated from the local system to WGS-84 system. The creation of the local elippsoid quasi-model is conditioned by the difference of 3D coordinates difference of three-dimensional of each point’s position. The values of the geoid wave vary within the range of 17.4547 meters, the average difference being almost in the centre of the area and is 21.2522 meters. To obtain the digital model of the quasi-geoid at the given local ellipsoid at each 100m a square matrix (of the network) was made by coordinates of recomputed points.

Hydrocarbon exploration in Argentina started long before the IGM created a single, high-precision geodetic reference network for the whole country. Several geodetic surveys were conducted in every producing basin, which have ever since then supported well placement. Currently, every basin has a huge amount of information referenced to the so-called “local” geodetic systems, such as Chos Malal – Quiñi Huao in the Neuquén Basin, and Pampa del Castillo in the San Jorge Basin, which differ to a greater or lesser extent from the national Campo Inchauspe datum established by the IGM in 1969 as the official geodetic network. However, technology development over the last few years and the expansion of satellite positioning systems such as GPS resulted in a new world geodetic order. Argentina rapidly joined this new geodetic order through the implementation of a new national geodetic system by the IGM: POSGAR network, which replaced the old national Campo Inchauspe system. However, this only helped to worsen the data georeferencing issue for oil companies, as a third reference system was added to each basin. Now every basin has a local system, the national system until 1997 (Campo Inchauspe), and finally the newly created POSGAR network national satellite system, which is geocentric unlike the former two planimetric datums. The purpose of this paper is to identify and allocate geodetic systems of coordinates to historical wells, whose geodetic system is missing or has been erroneously allocated, by using currently available technological resources such as geographic information systems and high-resolution satellite imagery.

For a connected graph G of order at least two, an outer connected geodetic set S in a connected graph G is called a minimal outer connected geodetic set if no proper subset of S is an outer connected geodetic set of G. The upper outer connected geodetic number g+ oc(G) of G is the maximum cardinality of a minimal outer connected geodetic set of G. We determine bounds for it and find the upper outer connected geodetic number of some standard graphs. Some realization results on the upper outer connected geodetic number of a graph are studied. The proposed method can be extended to the identification of beacon vertices towards the network fault-tolerant in wireless local access network communication. Also, another parameter forcing outer connected geodetic number fog(G) of a graph G is introduced and several interesting results and realization theorem are proved.

Abstract The broader area of Athens, a region exhibiting relatively low crustal deformation, was stroke in 1999 by a catastrophic earthquake posing serious questions regarding strain accumulation in slow deforming regions located within active geodynamic regimes. In the present study, the establishment of a dense geodetic network, primarily designed to monitor local tectonic movements is reported. A comprehensive GNSS velocity field, over the period 2005–2008, as well as calculated geodetic strain rates is presented. It is shown that a single strain tensor is insufficient to express the heterogeneity of the local geodetic field. Local variability of strain is successfully depicted, indicating the western part of Athens as the area of higher strain accumulation. Maximum dilatation rates occur along a NNE-SSW direction between Parnitha Mt. and Thriasio basin. The observed dilatation can be associated to WNW-ESE trending active fault zones, which appear to abruptly terminate towards East along a major NNE-SSW Miocene tectonic boundary. These findings are consistent to the stress field responsible for the Athens 1999 earthquake, also in agreement with geological and tectonic observations. Finally, the implications of the observed motion field on the understanding of the kinematics and dynamics of the region as well as the role of inherited inactive tectonic structures are discussed.

[EN] The goal of this research is to analise and to develop a system that allows the determination of the most general movement dynamics of a tall building, as well as to quantify its evolution over time by means of Gaussian algorithms revision and by applying GNSS techniques and methodologies. In this thesis, the oscillation of the control quadrilateral located on the roof of the ``Torre Espacio'' bulding and determined by a high precision survey network is assessed rigorously with the method of sequential solution with addition of variables or parameters using VRS-RTK techniques. It is the data processing, together with the gaussian adjustment methodology based on a conditional tax own physical reality and analysis of partial and final results allowing us to achieve a high level of confidence that translates into effective management real-time risk. In parallel, the instantaneous and simultaneous precision of each antenna in every moment is determined. That is the error surface and the individual, simultaneous reliability of each GNSS receiver. Prior to assessing the structure dynamics, the sensitivity threshold is computed, under which nothing can be affirmed or denied with respect to the displacement produced in the control structure. It involves testing the accuracy of the instrumentation GNSS and gaussian initial adjustment mathematical model. The project concludes with the development of a warning system that is activated at the time when the movement of the building reaches a preset threshold.
[ES] El objeto de la investigación es analizar y desarrollar un sistema que permita determinar la dinámica más general del movimiento de un edificio de gran altura, así como cuantificar su evolución en el tiempo. Dicho sistema se plantea mediante la revisión de los algoritmos gaussianos y la aplicación de metodologías y técnicas GNSS. En este trabajo se determina rigurosamente, mediante el método general de Ajustes Coordinados con adición de funciones de variables o parámetros, la situación de oscilación del cuadrilátero de control conformado por una red microgeodésica local y observado con técnicas VRS-RTK ubicado en la planta de coronación del edificio Torre Espacio de Madrid. Es precisamente el tratamiento de los datos, la metodología gaussiana de ajuste en función de un condicionado propio impuesto por la realidad física y el análisis de los resultados parciales y finales lo que nos permite alcanzar un alto nivel de fiabilidad que se traduce en una gestión eficaz del riesgo en tiempo real. Paralelamente se determina la precisión instantánea y simultánea de cada antena y en cada momento, esto es la superficie de error y la fiabilidad individual y simultánea de la posición de cada receptor GNSS. Previo a la evaluación de la dinámica de la estructura, se calcula el umbral de precisión o ``sensibilidad'', por debajo del cual nada puede afirmarse o negarse con respecto al desplazamiento producido en la estructura a controlar. Supone contrastar la precisión de la instrumentación GNSS y del modelo matemático inicial de ajuste gaussiano. El proyecto concluye con el desarrollo de un sistema de alerta que se activa en el momento en que el movimiento del edificio alcanza un umbral preestablecido.
[CAT] L'objecte de la investigació és analitzar i desenvolupar un sistema que permeta determinar la dinàmica més general del moviment d'un edifici de gran alçada, així com quantificar la seua evoluvió en el temps. Aquest sistema es plantaja mitjançant la revisió dels algorismes Gaussians i l'aplicació de metodologies y tècniques GNSS. En aquest treball es determina rigorosament, mitjançant el mètode general d'Ajusts Coordinats amb adició de de funcions de variables o paràmetres, la situació d'oscilació del quadrilàter de control conformat per una xarxa microgeodèsica local i observant amb tècniques VRS-RTK localitzat a la planta de coronació de l'edifici TorreEspacio de Madrid. És precisament el tractament de les dades, la metodologia Gaussiana d'ajust en funció d'un condicionat propi imposat per la realitat física y l'anàlisi dels resultats parcials i finals el que ens permet arribar a un alt nivell de fiabilitat, que es tradieix en una gestió eficaç del risc en temps real. Paral·lelament es determina la precisió instantània i simultània de cada antena i en cada moment, es a dir la superfície d'error i la fiabilitat individual i simultània de la posició de cada receptor GNSS. Previament a l'evaluació de la dinàmica de l'estructura, es calcula l'umbral de precisió o ``sensibilitat'', per davall de la qual no es por afirmar o negar res respecte al desplaçament produït en l'estructura a controlar. Això suposa contrastar la precisió de la instrumentació GNSS i del model matemàtic inicial d'ajust Gaussià. El projecte conclou amb el desenvolupament d'un sistema d'alerta que s'activa en el moment en que el moviment de l'edifici arriba a un umbral preestablert.
Quesada Olmo, MN. (2015). Desarrollo y análisis de un sistema para la determinación de la dinámica del movimiento más general de la azotea de un edificio de gran altura y su evolución en el tiempo [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58993
TESIS

U doktorskoj disertaciji je prikazan postupak optimizacije podzemne mrežeza potrebe izgradnje beogradskog metroa. U postupku optimizacije korišćenje metod prethodne ocene tačnosti. Na osnovu građevinskih standardaizvršen je proračun zahtevane tačnosti proboja tunela, kao osnovnogkriterijuma tačnosti za razvijanje podzemne tunelske mreže. U postupkuoptimizacije analizirani su različiti planovi opažanja, kao i dobijeni rezultatiprethodne analize za svaki plan pojedinačno. Na osnovu zadatog kriterijumamaksimalne poprečene greške proboja tunela usvojen je konačan planopažanja.
The docotoral thesis presents an optimization method of the undergroundnetwork for the construction of the Belgrade metro. In the process ofoptimization, method of preanalysis has been used. Based on theconstruction standards, the calculation of the required breakthroughaccuracy, as the fundamental criteria of accuracy for the development of theunderground tunnel network, has been made. In the process of optimizationdifferent plans of observations have been analyzed, as well as the resultsobtained from the preanalysis for each plan individually. Based on therequired criteria of maximal transverse error of the tunnel breakthrough, thefinal plan of observations has been adopted.

Establishing a claim to the continental shelf is very much dependent on being able to establish base lines, locations, distances and water depth with a high degree of accuracy. Although this has always been the case, it has become much more significant with the increasing accuracy of measurement instrumentation, the introduction of global (satellite) positioning systems, and the need for international collaboration and agreement. This chapter outlines the measurements or calculations relating to position on the surface of the Earth, the geodetic principles underlying the concepts of coordinates and their reference systems, and the level of accuracy with which positions can be determined. Until the advent of satellite positioning and navigation systems, and in particular the Global Positioning System (GPS), geodetic coordinate systems were of little interest to many of the users of coordinate position information. Indeed, many of today's problems stem from historical misunderstanding of the true complexity of systems of coordinates (Ashkenazi, 1986). The first section of this chapter describes a number of common types of coordinate representation, their implementation in the definition of coordinate systems, and the interpretation of these systems with reference data. Examples of typical local, regional, and geocentric data are outlined as illustration of the general principles. In order to combine coordinates based on differing systems, be it the combination of different national systems or of a national and a geocentric system, it is also necessary to understand the methods of transforming coordinates from one system to another. Details of these methods are presented. Coordinate values within the described systems will usually have been obtained through geodetic observation of national (or international) control networks, with subsequent measurement of detail referenced to those network stations. The chapter therefore gives a brief description of geodetic networks before discussing in some detail the theory of errors and related accuracy analysis which is required in order that realistic accuracy estimates can be ascribed to positional information. The final section presents the definitions and calculation algorithms relating to geodetic distance determination on the Earth's surface, with emphasis on the geodesic— the shortest line between points on an ellipsoidal reference surface, and therefore the line that all distances in article 76 are referred to.

Ubiquitous computing and The Internet-of-Things (IoT) grow rapidly in today's life and evolving to Self-organizing systems (SoS). A unified and scalable information processing and communication methodology is required. In this work, mobile agents are used to merge the IoT with Mobile and Cloud environments seamless. A portable and scalable Agent Processing Platform (APP) provides an enabling technology that is central for the deployment of Multi-Agent Systems (MAS) in strong heterogeneous networks including the Internet. A large-scale use-case deploying Multi-agent systems in a distributed heterogeneous seismic sensor and geodetic network is used to demonstrate the suitability of the MAS and platform approach. The MAS is used for earthquake monitoring based on a new incremental distributed learning algorithm applied to seismic station data, which can be extended by ubiquitous sensing devices like smart phones. Different (mobile) agents perform sensor sensing, aggregation, local learning and prediction, global voting and decision making, and the application.

During reconstruction and restoration of city geodetic networks, there is quite a common problem that is related to the nonhomogeneity of existing geodetic networks. In any city, local authorities operate with their coordinate systems. Such conditions lead to inconsistency between data of different services. There is only one way how to overcome the problem that lies in the creation and deployment of the new common coordinate system for the whole city. But such an approach has a lack connected with the necessity of transformation parameters acquisition for the latest and old coordinate systems. Insofar as old coordinate systems had been created with different accuracy, using various equipment, and measuring technologies, it is not possible to consider them as homogeneous. It means that we cannot use a classical conformal Helmert transformation to link different coordinate systems. In the presented paper were studied the different approaches for transformation parameters acquisition. A case study of the Almaty city coordinate system was researched and compared the following methods: Helmert transformation, bilinear transformation, the second and third-order regression transformation, and the fourth-order conformal polynomial transformation. It was found out that neither of the considered methods maintains the necessary transformation accuracy (>5 cm). That is why the creation of the transformation field using the finite element method (FEM) was suggested. The whole city was divided into triangles using Delaunay triangulation. For each triangle, the transformation parameters were found using affine transformation with the necessary accuracy.