scholarly journals GIScience Theory Based Assessment of Spatial Disparity of Geodetic Control Points Location

2020 ◽  
Vol 9 (3) ◽  
pp. 148
Author(s):  
Elzbieta Bielecka ◽  
Krzysztof Pokonieczny ◽  
Sylwia Borkowska
Keyword(s):  
Nearest Neighbor ◽  
Geodetic Network ◽  
Control Points ◽  
Outlier Analysis ◽  
Geodetic Networks ◽  
Land Administration ◽  
Ex Post ◽  
Spatial Cluster Analysis ◽  
Geodetic Control ◽  
Application Fields

Geodetic networks provide a spatial reference framework for the positioning of any geographical feature in a common and consistent way. An even spatial distribution of geodetic control points assures good quality for subordinate surveys in mapping, cadaster, engineering activities, and many other land administration-oriented applications. We investigate the spatial pattern of geodetic control points based on GIScience theory, especially Tobler’s Laws in Geography. The study makes contributions in both the research and application fields. By utilizing Average Nearest Neighbor, multi-distance spatial cluster analysis, and cluster and outlier analysis, it introduces the comprehensive methodology for ex post analysis of geodetic control points’ spatial patterns as well as the quantification of geodetic networks’ uniformity to regularly dense and regularly thinned. Moreover, it serves as a methodological resource and reference for the Head Office of Geodesy and Cartography, not only the maintenance, but also the further densification or modernization the geodetic network in Poland. Furthermore, the results give surveyors the ability to quickly assess the availability of geodetic points, as well as identify environmental obstacles that may hamper measurements. The results show that the base geodetic control points are evenly dispersed (one point over 50 sq. km), however they tend to cluster slightly in urbanized areas and forests (1.3 and 1.4 points per sq. km, respectively).

scholarly journals Control Points Selection Based on Maximum External Reliability for Designing Geodetic Networks

2020 ◽  
Vol 10 (2) ◽  
pp. 687 ◽  
Author(s):  
Marcelo Tomio Matsuoka ◽  
Vinicius Francisco Rofatto ◽  
Ivandro Klein ◽  
Maurício Roberto Veronez ◽  
Luiz Gonzaga da Silveira ◽  
...  
Keyword(s):  
Control Point ◽  
Modern Science ◽  
Geodetic Network ◽  
Control Points ◽  
Geodetic Networks ◽  
Optimum Position ◽  
Network Coordinates ◽  
Detectable Bias ◽  
Engineering Projects ◽  
Selection Of

A set of stable and identifiable points—known as control points—are interconnected by direction, distance or height differences measurements form a geodetic network. Geodetic networks are used in various branches of modern science, such as monitoring the man-made structures, analysing the crustal deformation of the Earth, establishing and maintaining a geospatial reference frame, mapping, civil engineering projects and others. One of the most crucial components for ensuring the network quality is Geodetic Network Design. The design of a geodetic network depends on its purpose. In this paper, an automatic procedure for selection of control points is proposed. The goal is to find the optimum control points location so that the maximum influence of an anomaly measurement (outlier) on the coordinates of the network is minimum. Here, the concept of Minimal Detectable Bias defines the size of the outlier and its propagation on the network coordinates is used to describe the external reliability. The proposed procedure was applied to design a levelling network. Two scenarios were investigated: design of a network with one control point (minimally constrained levelling network) and another with two control points (over-constrained levelling network). The centre of the network was the optimum position to set the control point. Results for that network reveal that the centre of the network was the optimum position to set the control point for the minimal constraint case, whereas the over-constraint case were those with less line connections. We highlight that the procedure is a generally applicable method.

scholarly journals Influence of distance, geometry and number of control stations on quality of local geodetic networks for the purpose of georeferencing of rural properties

2014 ◽  
Vol 34 (2) ◽  
pp. 311-321 ◽  
Author(s):  
David Luciano Rosalen
Keyword(s):  
Statistical Tests ◽  
Distance Geometry ◽  
Geodetic Network ◽  
Maximum Distance ◽  
Baseline Length ◽  
Technical Standard ◽  
Geodetic Networks ◽  
Geodetic Control

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.

Applications of Statistical Characteristics of Geodetic Networks

1974 ◽  
Vol 28 (5) ◽  
pp. 702-708
Author(s):  
L. A. Gale
Keyword(s):  
Observational Data ◽  
Geodetic Network ◽  
Statistical Information ◽  
Statistical Characteristics ◽  
Geodetic Networks ◽  
Control File ◽  
Geodetic Control ◽  
Inner Constraint

Numerous statistics that can be obtained from the processing of the observations and the adjustment of a geodetic network can be used to assess the quality of the network and the observational data. The processes used for assessment and planning depend on the needs and the capabilities of the user. Statistical information derived from nonsingular vis-à-vis singular (“inner-constraint”) adjustments is discussed. Standards for the characterization of the quality of networks are reviewed. Suggestions are made on the type of information that should be directly available from a geodetic control file.

scholarly journals Control Points Selection based on Maximum External Reliability for Designing Geodetic Networks

2019 ◽  
Author(s):  
Marcelo Tomio Matsuoka ◽  
Vinicius Francisco Rofatto ◽  
Ivandro Klein ◽  
Mauricio Roberto Veronez ◽  
Luiz Gonzaga Da Silveira ◽  
...  
Keyword(s):  
Modern Science ◽  
Geodetic Network ◽  
Quality Criteria ◽  
Control Points ◽  
Geodetic Networks ◽  
Optimum Configuration ◽  
Network Problems ◽  
Detectable Bias ◽  
Observation Vector ◽  
Engineering Projects

Geodetic networks are essential for most geodetic, geodynamics and civil projects, such as monitoring the position and deformation of man-made structures, monitoring the crustal deformation of the Earth, establishing and maintaining a geospatial reference frame, mapping, civil engineering projects and so on. Before the installation of geodetic marks and gathering of survey data, geodetic networks need to be designed according to the pre-established quality criteria. In this study, we present a method for designing geodetic networks based on the concept of reliability. We highlight that the method discards the use of the observation vector of Gauss-Markov model. In fact, the only needs are the geometrical network configuration and the uncertainties of the observations. The aim of the proposed method is to find the optimum configuration of the geodetic control points so that the maximum influence of an outlier on the coordinates of the network is minimum. Here, the concept of Minimal Detectable Bias defines the size of the outlier and its propagation on the parameters is used to describe the external reliability. The proposed method is demonstrated by practical application of one simulated levelling network. We highlight that the method can be applied not only for geodetic network problems, but also in any branch of modern science.

scholarly journals SATELLITE POSITIONING BASED EXTENSION OF GEODETIC REFERENCE NETWORK TO SUPPORT GEOSPATIAL APPLICATIONS

2018 ◽  
Keyword(s):  
Control Point ◽  
Geodetic Network ◽  
Computational Techniques ◽  
Reference Network ◽  
Control Points ◽  
Positioning Systems ◽  
Satellite Positioning ◽  
Geodetic Control ◽  
Office Software ◽  
Central Kenya

A national geodetic network provides the fundamental framework that enables attainment of high accuracy geodetic measurements. It plays a key role in the efficiency and reliability of operations in land surveying, mapping, remote sensing, Geographic Information System, engineering surveying and other related applications. The geodetic framework provides the basis for integrating all mapping and survey activities. About eighty per cent of the primary geodetic control points in Kenya, established in the early twentieth century, have been destroyed. This has resulted in expensive and time consuming operations and processes for geospatial professionals and scientists. This situation is particularly worse in central Kenya, hence the need to extend the geodetic control by establishing more control points on secure and accessible sites for use by geospatial professionals and scientists in a wide variety of applications. In this study, modern satellite positioning techniques were utilised to extend geodetic reference network in central Kenya. Existing geodetic control points were used to facilitate establishment of new geodetic control points distributed within the region. Field observations were carried out using Global Positioning System. The raw data were downloaded, edited, processed and adjusted using Leica Geo-Office software. The resulting final adjusted coordinates had a maximum standard deviation of 2cm and 5cm on horizontal and vertical coordinates respectively, and a general loop misclosure of less than one part per million. The results showed that the quality of established control point positions was high, and demonstrated the efficient extension of geodetic control network using modern satellite positioning systems and efficient computational techniques in situations such as the ones currently prevailing in central Kenya.

scholarly journals Influence of the Datum Definition on the Accuracy of Horizontal Geodetic Control Networks for Engineering Objects

2019 ◽  
Vol 8 (3) ◽  
pp. 99-106
Author(s):  
Nedim Tuno ◽  
Admir Mulahusić ◽  
Jusuf Topoljak
Keyword(s):  
Geodetic Network ◽  
Control Points ◽  
Engineering Structures ◽  
Control Networks ◽  
Geometrical Distribution ◽  
Quality Of Control ◽  
Design And Implementation ◽  
Triangulation Network ◽  
Geodetic Control

For the construction of various civil engineering structures, particular care should be taken in the perspective of geodetic control. Therefore, the design and implementation of the geodetic network deserves special attention. This paper is focused on various aspects of datum definitions for tested micro-triangulation network. It was shown that the geometrical distribution of datum points in a minimally constrained solution has a great impact on the accuracy of the geodetic network. Estimates of the accuracies of individual station y-x coordinates, error circles and error ellipses, obtained by free adjustment, where the datum selection was independent of errors in fixed coordinates, revealed much better quality of control points.

scholarly journals Research of technical characteristics of wall leveling signs in the context of the ethymology of terms

2021 ◽  
Vol 41 (I) ◽  
pp. 55-60
Author(s):  
I. TREVOHO ◽  
◽  
A. DRBAL ◽  
E. ILKIV ◽  
M. GALYARNYK ◽  
...  
Keyword(s):  
Geodetic Network ◽  
The Black Sea ◽  
Historical Sources ◽  
Term Operation ◽  
Geodetic Networks ◽  
City Environment ◽  
Technical Developments ◽  
The City ◽  
Technical Recommendations

The aim is to clarify the etymology of the terms “wall leveling mark” and “wall leveling benchmark” in the context of the historical sequence of the appearance of leveling networks in the Ukrainian lands to present the author’s view on these definitions in scientific reference and encyclopedic geodetic literature. To conduct a chronological study of the phenomenon of leveling wall signs of different structures and the corresponding technologies of binding to them in leveling networks, which were created in the Ukrainian lands during the XIX–XXI centuries. Pay attention to the fact that level marks and wall frames, which are valid (working) independent geodetic signs in leveling networks, due to long-term operation are carriers of important geodetic information. Method. To study the results of the analysis of historical sources, standards, reference, encyclopedic and scientific literature in the context of the analysis of the definitions of “level mark” and “wall benchmark” was used analysis of patterns of functioning of the relevant geodetic terminological units. Results. On the territory of Ukraine during the XIX–XXI centuries. Created a leveling (height) network [State Geodetic Network, experimental operation], which operates to this day. The functioning of the leveling (height) network is regulated by legislative acts and regulations. Thanks to the geo-portal of the DGM of Ukraine created by NDIGK, it is possible to obtain information about the preserved level signs. The peculiarity of the leveling (height) network is that it was created by different departments of different countries [Glushkov V.V., 2003] with different height systems and taking into account the access of Ukrainian lands to the Black Sea. All this led to the use of different designs of wall leveling signs and, accordingly, their interpretation, which is not sufficiently reflected in the geodetic reference and regulatory literature. Scientific novelty. The performed comprehensive analysis of information sources can serve as a basis for development of scientific and technical recommendations formonitoring of level signs ofDGMofUkraine and will allow to reveal weaknesses of their functioning which are caused by changes in vital activity of the city environment. The practical value of the work is to solve the problem of distinguishing the production characteristics of the wall leveling mark and wall leveling benchmark, which are fixed leveling signs in geodetic networks of thickening and leveling networks to develop technical developments for inspection and updating points II, leveling networks classes and geodetic networks of thickening in the context of monitoring of geodetic points of DGM of Ukraine and their corresponding representation in the scientific and reference geodetic literature.

scholarly journals Design and Geodetic Adjustment of Levelling Network for Establishment of Unified Control Points in Korea

2021 ◽  
pp. 29-40
Author(s):  
H.K Lee ◽  
S.H. Yun ◽  
J.H. Kwon ◽  
J.S. Lee
Keyword(s):  
Pilot Study ◽  
Vertical Component ◽  
Reference Points ◽  
Spatial Density ◽  
Control Points ◽  
Network Adjustment ◽  
Technical Challenge ◽  
Adjustment Procedure ◽  
Geodetic Control ◽  
Horizontal Network

The unified control points (UCPs), the multi-dimensional geodetic reference points installed in the low elevated area, has been established in Korea for the combination of the horizontal and the vertical geodetic control. While the 1st-phase UCPs network was completed in 2011 with a spatial density of about 10km, its densification has been underway as the 2nd-phase project. The UCPs supersedes the legacy geodetic points, such as triangulation points and benchmarks (BMs) once the 2nd-phase implementation. Although the horizontal network of the UPCs can be readily realised by GNSS technology, a technical challenge of the vertical component remains to be settled due to characteristics of the geodetic levelling technique. To this end, a pilot study was conducted to design a new version of the UCPs-based levelling network and to demonstrate its effectiveness with a comparison of the legacy. In this paper, a concept of the UCPs-based levelling network is briefly addressed with some prominent examples, and details of a pilot network and its measurements is given with the network adjustment procedure. Finally, results of the adjustments are provided with an emphasis on the influence of the newly designed network in terms of accuracy, reliability and estimated heights.

scholarly journals A LIBRATION MODEL FOR ENCELADUS BASED ON GEODETIC CONTROL POINT NETWORK ANALYSIS

2016 ◽  
Vol XLI-B4 ◽  
pp. 459-462 ◽  
Author(s):  
I. E. Nadezhdina ◽  
A. E. Zubarev ◽  
E. S. Brusnikin ◽  
J. Oberst
Keyword(s):  
Network Analysis ◽  
Coordinate System ◽  
Control Point ◽  
Image Data ◽  
Control Points ◽  
Global Control ◽  
Cartesian Coordinates ◽  
Voyager 2 ◽  
Librational Motion ◽  
Geodetic Control

A new global control point network was derived for Enceladus, based on Cassini and Voyager-2 image data. Cassini images were taken from 2005 to 2014, for Voyager we have only one flyby in the middle of 1981. We have derived 3D Cartesian coordinates for 1128 control points as well as improved pointing data for 12 Voyager and 193 Cassini images in the Enceladus-fixed coordinate system. The point accuracies vary from 55 m to 2900 m (average point accuracy – 221 m). From tracking of the control points we detect a librational motion described by a model which includes 3 different periods and amplitudes (Rambaux et al., 2011). We determine the amplitudes for each term. Our new control point network has a higher number of point measurements and a higher accuracy than previous data (Giese et al., 2014).

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