Geodetic Points Research Articles

Geodesic monitoring of ground deformations at Klyuchevskoy Volcano in 1978–2014, Kamchatka

Measured values are given - slant distances and elevations between geodetic marks on the northeast slope of Klyuchevskaya volcano for 1978–2014. As a rule, a rise was observed before the secondary and summit eruptions, and the end of the eruptions was accompanied by the lowering of the volcano slope. According to the longest series of observations of vertical displacements from 1979 to 2014. on the “Kirgurich” radial profile, the rise of the volcano slope is determined to increase as it approaches its crater. The maximum displacements occurred two years before the start of the “Predskazannuy” side breakthrough in 1983, and before the summit eruptions of 2003–2004 and 2007. At a distance of 27 km from the crater of the volcano, the vertical displacements become insignificant. It is shown that points located at altitudes from 2000 meters to 3000 meters are subject to deep creep, i.e. sliding down. The displacement rates of such points reached 5–20 cm/year. Significant horizontal displacements of geodetic points occurred near incidental breaks on March 6, 1980 and March 8, 1983. From 1989–1993. until 2014, reductions of all lengths of lines from 5 to 20 mm were observed, which indicated compression of the northeast slope of Klyuchevskaya volcano.

Исследование возможностей использования постоянно действующих референцных станций в высокоточной геодезии и геодинамике

The author studies an opportunity of using GNSS observations on permanent geodetic reference points (base stations) for the high-precision geodesy and geodynamics purposes. It is assumed such GNSS observations may not completely meet the settled rules for GNSS observations in precise geodetic positioning. On the basis of processing real GNSS observations on the Moscow region’s reference stations in the course of seven years period an investigation of changing reference station positions was performed and typical variations and distortions that arise in positions of reference points during this long time period figured out. An analysis of possible reasons of occurring these effects and ways of eliminating them was carried out. Preliminary proposals how to filter out these adverse effects and bring the quality of GNSS processing results to the level required for the purposes of high precision geodesy and geodynamics were suggested.

The Integrated Management of Information about the Geodetic Point Fields—A Case of the Czech Republic

The geodetic point fields play a crucial role in measuring a terrain, in surveying, and mapping applications. Due to the rapid development in the domain of information technologies, it makes sense to consider using the database and web technologies to manage and disseminate the available information about the geodetic point fields. The paper presents the creation of a spatial database which integrates the information about the various kinds of established geodetic point fields (horizontal, vertical and gravitational) with the aim of enabling their effective management. Furthermore, based on the integrated spatial database, the prototype of the new information system of geodetic point fields has been developed. The functionality of the prototype also considers the requirements coming from the international efforts, i.e., the Infrastructure for Spatial Information in Europe (INSPIRE) directive. The prototype, based on Java Enterprise Edition (EE) technology, implements the features reflecting the cyber-security issues and ensures the modularity and scalability of the system, which is important for further development of the system and dissemination and accessibility of the information about the geodetic point fields via modern web technologies.

Análise dos resultados de processamentos de dados GNSS aplicado ao monitoramento de estruturas, utilizando efemérides transmitidas, precisas e o posicionamento por ponto preciso do IBGE

Objetivando-se obedecer às normas de segurança de barragens e à legislação vigente, neste trabalho buscou-se alcançar precisões compatíveis com o monitoramento da barragem da UHE Mauá, no rio Tibagi, utilizando a tecnologia GNSS de precisão, método de posicionamento relativo estático. Para obtenção de coordenadas e seus respectivos desvios-padrão dos pontos da rede geodésica de monitoramento, foram abordados pós-processamentos de dados brutos utilizando-se linhas de base longa e curta, efemérides transmitidas, efemérides precisas e posicionamento por ponto preciso (PPP). Constatou-se que a utilização de efemérides transmitidas foi satisfatória, o que permite o processamento no dia seguinte à realização da campanha de coleta de dados. A utilização de efemérides precisas correspondeu ao esperado, quando utilizada a linha de base curta. Porém, a desvantagem está no lapso temporal para processamento de, no mínimo, 14 dias após a realização da campanha. O PPP e a linha de base longa resultaram desvios-padrão superiores àqueles obtidos com efemérides precisas e transmitidas e linha de base curta e, portanto, foram considerados como desaconselháveis à utilização em monitoramento de estruturas.

Mekansal istatistiklerin bir uygulaması: Simule edilmiş fay düzlemine ilişkin jeodezik noktaların mekansal analizi

In this study, simulated fault plane geodetic points are analyzed by using spatial statistics. The synthetic geodetic points are generated to understand the basic spatial structure of the fault plane because of the difficulty about obtaining real data set. The spatial statistics are applied to geodetic point data with three main items: (i) spatial descriptive statistics, e.g. spatial mean (center mean-CM), standard distance (SD), standard deviational ellipse (SDE), (ii) spatial pattern analyses, e.g. quadrat count method, the nearest neighbor approach, (iii) spatial autocorrelation, e.g. Moran’s I index. It is seen from the application results that spatial autocorrelation should be taken into consideration during the spatial analysis of geodetic point data to understand if the surface displacements on the locations are clustered or not.

Effectiveness of Centering Devices of Geomatics Instruments

Manufacturers of geomatics instruments have designed a number of centering devices to perform appropriate positioning over surveying and geodetic points, and to reproduce these positions as many times as needed. Depending on the accuracy requirements of metrological, geodetic or topographic work, a choice can be made between conventional-centering or forced-centering, taking in to account commonly accepted deviations for each type of centering device. Miscentering values are currently stablished in two ways: through “experience” or from tests involving angular and linear measurements performed by surveying instruments placed on the tested centering devices. None of these methods is adequate enough to determine the true capabilities of centering systems. This gap in the analysis of a relevant field in high accuracy geomatics projects and metrological testing of geomatics instruments has encouraged this study. A new method for assessing the accuracy of centering devices is presented. This method avoids surveying measurements and takes advantage of the capabilities of two high-precision measuring devices—coordinate measuring machine (CMM) and measuring arm—as reference instruments, which ensure that the results have been determined in a fairly reliable way. The procedures performed with this new method applied to four centering devices and the corresponding results are exposed.

Construcción de la superficie hidrográfica de referencia vertical para las bahías de Buenaventura y Málaga, Pacífico colombiano

El presente artículo define la ruta metodológica usada en el proyecto “Red Hidrográfica de Referencia Vertical para los principales puertos marítimos Colombianos”, durante la generación del marco vertical de referencia denominado “Superficie Hidrográfica de Referencia Vertical (SHRV2016)” para las bahías de Buenaventura y Málaga en el Pacífico Colombiano, a partir de tres componentes principales: la determinación matemática de datums verticales asociados a registros históricos de nivel de agua, el establecimiento de una red de vértices geodésicos de primer orden, y la medición de alturas en la superficie del mar con referencia al elipsoide WGS84 (World Geodetic System), empleando receptores del sistema GNSS (Global Navigation Satellite System) en modo diferencial RTK (Real Time kinematic). Los puntos de referencia en tierra fueron utilizados para dar el control vertical de precisión hacia los datums en el agua, y a su vez para la instalación de receptores base GNSS encargados de enviar las correcciones diferenciales en tiempo real durante la medición de alturas en la superficie del mar; Estas mediciones junto a la densificación de datums verticales calculados para la zona, constituyeron la base en la elaboración de la SHRV2016, modelo que con una resolución espacial de 500 metros, refiere al elipsoide WGS84 los datums verticales de nivel de agua, y que además de estandarizar las mediciones que realizan los diferentes usuarios en las aguas jurisdiccionales relativas a un datum vertical; permite aprovechar las ventajas de la tecnología GNSS para realizar la medición y corrección de nivel de agua en tiempo real con el menor grado de incertidumbre posible durante la ejecución de levantamientos hidrográficos, optimizando tiempo, calidad y recursos, especialmente en lugares como las Bahías de Buenaventura y Málaga, donde el régimen de marea hace compleja la actividad de corrección debido a la variabilidad en rango y fase propia del sector, lo cual obliga a instalar múltiples estaciones mareográficas, realizar tareas de topografía y geodesia en lugares de difícil acceso, y esperar al termino del levantamiento hidrográfico para incluir los registros de las estaciones en la corrección final de las profundidades. En un mediano plazo, las SHRV permitirán la generación de un modelo completo de referencia de los datums de marea hacia el elipsoide, que abarque completamente los litorales y regiones insulares del país, hasta los límites del mar territorial, gracias a la combinación con datos de altimetría satelital e instrumentos de observación mar adentro como boyas GPS, que permitan la correcta fusión con los modelos generados a nivel local en cada una de las bahías y puertos.

High Accuracy Geodetic Control Point Measurement Using GPS Geodetic With Static Methods

Abstract. The quality of the coordinates of the points in a generally horizontal control network will be influenced by many factors, such as the system equipment used for measuring / observation, the network geometry, measurement strategies / observation, as well as data processing strategy implemented. Using development of the GPS satellite system, since 1989, the network provision of horizontal control points in Indonesia generally relies on the GPS satellite observations. One way of measuring geodetic control points with high accuracy is using geodetic GPS. Measurement of geodetic control points required as a control in the execution of the work and as a correction coordinate measurement of the position of a measurement object with a high degree of accuracy (± 1 cm). How many measurement methods that can be done. This research conducted measurement using static method. Static surveys are used to determine the coordinates of the control points are relatively distant from each other as well as order accuracy requires relatively higher. The measurement results obtained coordinate data for point 1 is 6 ° 57 '31.92207 "LS; 109 ° 38 '32.25194 "BT; high (ellipsoid) 34 320 m and point 2 is 6 ° 57 '33.59086 "LS; 109 ° 38 '37.87710 "BT; high (ellipsoid) 36 235 m.

Алгоритм оценки дивергенции векторных полей движений земной поверхности по геодезическим данным

Geodetic measurements provide important and statistically estimated information about the coordinates of geodetic points and their changes over time. This geodesic information can be used to study geodynamic processes and their manifestations, primarily on the earth’s surface. Particularly intense such geodynamic phenomena occur in areas of active development of minerals due to the intense man-made effects on the near-surface layer of the Earth. It is logical to perform the description of surface motions using mathematical field theory. According to the changes of geodetic elements (coordinates, heights, directions) after repeated measurements it is possible to imagine the field of displacement vector of geodetic points. When studying the stress-strain state of the earth’s surface, the vectors obtained can be used not only to calculate the earth’s deformation tensor in the area under study, but also the differential characteristics of the vector field. One of them is called divergence. The authors of the article propose to determine the divergence of the vector field of surface displacements by discrete geodesic observations of displacement vectors made only on the surface of the study area. The model of the vector displacement field can be chosen taking into account the set of source data and the density of placement of geodetic points, the carriers of spatial coordinates.

NEW METHODS OF ACCOUNTING FOR VERTICAL REFRACTION WITH TRIGONOMETRIC LIVELING IN THE CONDITIONS OF THE REPUBLIC OF UZBEKISTAN

In the conditions of Uzbekistan, a simple and ordinary method of refraction is used to determine the relative elevations without vertical refraction coefficient or angle. Described that these methods require a two-sided simultaneous or non-simultaneous geodetic measurements. Working formulas for vertical refraction are presented by calculating vertical gradients in geodetic measurement points.

Spline approximation, Part 1: Basic methodology

Abstract In engineering geodesy point clouds derived from terrestrial laser scanning or from photogrammetric approaches are almost never used as final results. For further processing and analysis a curve or surface approximation with a continuous mathematical function is required. In this paper the approximation of 2D curves by means of splines is treated. Splines offer quite flexible and elegant solutions for interpolation or approximation of “irregularly” distributed data. Depending on the problem they can be expressed as a function or as a set of equations that depend on some parameter. Many different types of splines can be used for spline approximation and all of them have certain advantages and disadvantages depending on the approximation problem. In a series of three articles spline approximation is presented from a geodetic point of view. In this paper (Part 1) the basic methodology of spline approximation is demonstrated using splines constructed from ordinary polynomials and splines constructed from truncated polynomials. In the forthcoming Part 2 the notion of B-spline will be explained in a unique way, namely by using the concept of convex combinations. The numerical stability of all spline approximation approaches as well as the utilization of splines for deformation detection will be investigated on numerical examples in Part 3.

Accuracy analysis of satellite measurements of the measurement geodetic control network on the southern Spitsbergen

Geodetic networks are very important in analyses of long-term monitoring deformation of natural objects in polar regions. The ground stability of geodetic reference points can give the quality of the results of geometry measures. Well measures give the purpose to environmental protection of measured natural objects (moraines, talus slopes, debris etc.). The main objective of this paper is to compare the adjustment of the geodetic network by the Least Square Method based on one (ASTRO) or two (ASTRO and NYA1) reference points with full rank and robust adjustment. The main adjustment steps with important numerical results are presented for both methods. The method how to detect the presence of the used wrong approximate coordinates of network points is addressed, and the detection approaches are given for both adjustment procedures. The results of both adjustment procedures summarized in the Conclusion indicate that the combination of these procedures is not suitable way of detecting errors in a geodetic network.

Оценка результатов спутниковых определений пунктов геодезической сети с различными сеансами наблюдений

Оценка результатов спутниковых определений пунктов геодезической сети с различными сеансами наблюдений

Establishment of Karadeniz Technical University Permanent GNSS Station as Reactivated of TRAB IGS Station

Abstract In recent years, Global Navigation Satellite Systems (GNSS) have gained great importance in terms of the benefi ts it provides such as precise geodetic point positioning, determining crustal deformations, navigation, vehicle monitoring systems and meteorological applications etc. As in Turkey, for this purpose, each country has set up its own GNSS station networks like Turkish National Permanent RTK Network analyzed precise station coordinates and velocities together with the International GNSS Service, Turkish National Fundamental GPS Network and Turkish National Permanent GNSS Network (TNPGN) stations not only are utilized as precise positioning but also GNSS meteorology studies so total number of stations are increased. This work is related to the reactivated of the TRAB IGS station which was established in Karadeniz Technical University, Department of Geomatics Engineering. Within the COST ES1206 Action (GNSS4SWEC) KTU analysis center was established and Trop-NET system developed by Geodetic Observatory Pecny (GOP, RIGTC) in order to troposphere monitoring. The project titled “Using Regional GNSS Networks to Strengthen Severe Weather Prediction” was accepted to the scientifi c and technological research council of Turkey (TUBITAK). With this project, we will design 2 new constructed GNSS reference station network. Using observation data of network, we will compare water vapor distribution derived by GNSS Meteorology and GNSS Tomography. At this time, KTU AC was accepted as E-GVAP Analysis Centre in December 2016. KTU reference station is aimed to be a member of the EUREF network with these studies.

Monitoring the deformation and strain analysis on the Ataturk Dam, Turkey

ABSTRACTEvery man-made structure creates certain risks — dams are no exception. Most failures in man-made structures that have occurred could have been avoided if the structures’ behaviour had been inspected, monitored, and analyzed continuously, and if proper corrective measures had been taken in a timely fashion. The DSI (The General Directorate of State Hydraulic Works), which is the institution responsible for dam safety, has long used surveying methods to measure the displacements of geodetic points as a part of dam monitoring policy. In this study, we focus on the dam's mechanical behaviour throughout a time period of more than 10 years. These study results have been derived from a separate, ongoing project that has monitored deformation on the Ataturk Dam and is now determining the water level of the reservoir. The project results show that although the dam body has become more stable and the water load behind the dam has increased, the rate of displacement of the dam has declined significantly. From these results, it can be seen that the reservoir water level can be increased evenly over time and that 542 m is the maximum water level of the dam's reservoir.

Analiza osiadania wybranych typów znaków osnowy geodezyjnej

W niniejszej pracy zawarto rozważania dotyczące możliwych przyczyn nadmiernego osiadania znaków osnowy geodezyjnej. Do analiz wybrano znaki ziemne osnowy wysokościowej typu 75a i b. Przeprowadzono analizę obliczeniową osiadania znaków osnowy geodezyjnej, pracujących w różnych warunkach gruntowych oraz w dwóch złożonych obciążeniach. W celu uwzględnienia w obliczeniach najbliższych rzeczywistym warunków współpracy pomiędzy elementami osnowy geodezyjnej, a ośrodkiem gruntowym, modyfikowano przyjmowane parametry. Uzyskane wyniki porównywano z zaobserwowanymi w powiecie kętrzyńskim w trakcie transformacji układu wysokościowego z Kronsztadt’60 na Kronsztadt’86. Wynikiem prac jest określenie możliwych zmian osnowy wysokościowej, w okresie pomiędzy kampaniami pomiarowymi (około 20 lat).

О реализации и оценке точности методики «Precise Point Positioning» (PPP)

The article notes that the replacement of the English name «Precise Point Positioning» (PPP) in Russian-language sources is possible using the term «accurate differential positioning» (TDP) technique. The author proposes to use both terms. This article contains information about the practical implementation of the PPP in the on-line service. The author has analyzed the research on the accuracy of PPP foreign and domestic experts and scholars. The author analyzed the data about the convergence time for PPP solutions. These data belong to another Russian scientist. The results of evaluating the accuracy of the PPP of different scientists led to the next. The author of this article gave the mean square errors topocentric coordinates of the geodetic points. The coordinates of the points must be obtained by dual-frequency GPS-measurements for a period of 24 hours with the help of PPP. The author proposed a formula for the calculation of the mean square error of the spatial position of geodetic point, if its position is obtained in the processing of dual-frequency GPS-observations of less than 24 hours. The article written conclusions about the features, defects and PPP development.

The 2D time-dependent similarity transformation model as a tool for deformation monitoring

Besides the methodology of triangulation and geodetic networks nowadays, the permanent stations of satellite receivers exist, giving extra asset to geodetic daily practice. Permanent stations perform observations incessantly for the visible satellites. However, the coordinates of these stations are often changing over time due to geophysical and tectonic processes. Consequently, these changes are perceived to modern observations. So, along with the coordinates of geodetic points in a given epoch, their changes over time (e.g. the velocities of their movements) are also considered. Furthermore, any change to the reference system definition or/and to the network’s geometry can significantly impact the estimated coordinates and velocities. This paper investigates the reference datum definition problem (or datum problem, or zero order design problem) in a such network over time, which is later generalized for the study of the deformation control-networks. Emphasis is given to techniques of time-dependent 2D transformation models, with numerical tests on a simulation network.

Исследование алгоритма для анализа деформаций геодезических пунктов при наблюдении за горизонтальными смещениями гидротехнических сооружений

In recent years, many hydraulic structures have been modernized and built in Vietnam. Monitoring the deformations of hydraulic structures are extremely important. The results of observations of deformations to assess the stability and safety of structures help specialists make the process of construction and reconstruction of hydraulic structures more reliable and safe. At present, a personal computer is very widely used in processing the results of geodetic measurements. By using algorithms on a computer, we can simply and quickly solve problems with a huge number of calculations. The article deals with the application of a recurrent way of equalizing for the analysis of deformations of geodetic points when observing horizontal displacement of hydraulic structures in Vietnam. The use of the proposed algorithm in this article is conveniently implemented in practical calculations using a computer. The result of the calculation of the example indicates that combining the observation cycles to increase the accuracy of the observed items.

THE USE OF ONLINE AND OFFLINE PROCESSING TOOLS TO IMPROVE THE PRECISION OF A GPS PASSIVE STATION

Founding of local geodetic points is very crucial for many purposes such as surveying and mapping. In 2011, a control marker was established at the engineering college, University of Duhok (UoD). A survey campaign was carried out to collect GPS raw data of roughly 121 h using Leica Viva GNSS tool at 1-second epoch. The aim was to install an accurate and dependable geodetic point which usually known as the passive station. The accuracy of the established point cannot be reliably checked or compared due to unavailability of any reliable and precise geodetic point near the survey marker. In this paper, investigating the accuracy of that recognized position using the statistical testing is aimed. For that reason, 121 h of raw data was broken into 36 sub-files covering five days of observations, each containing a full of 24 h, 12 h and 6 h of data at 1-second epoch. The data was separately processed utilizing different processing solutions such as free available online PPP services and post processing desktop tool. The aim is to compare the position of each of the subsamples with the most probable value. The results showed that the last recognized and dependable point coordinates are 314075.7788, 4080892.2610, and 525.1899 (m) with RMSE ±3.7, ±3.9, ±6.2 (mm), respectively.