scholarly journals GEOMETRIC ASPECTS EVALUATION OF GNSS CONTROL NETWORK FOR DEFORMATION MONITORING IN THE JATIGEDE DAM REGION

2019 ◽  
Vol 15 (2) ◽  
pp. 167
Author(s):  
Made Ditha Ary Sanjaya ◽  
T. Aris Sunantyo ◽  
Nurrohmat Widjajanti
Keyword(s):  
Least Squares ◽  
Deformation Monitoring ◽  
Network Configuration ◽  
Control Networks ◽  
Quality Of Control ◽  
Least Squares Adjustment ◽  
Standard Deviations ◽  
Dam Deformation ◽  
Gnss Networks

Many factors led to dam construction failure so that deformation monitoring activities is needed in the area of the dam. Deformation monitoring is performed in order to detect a displacement at the control points of the dam. Jatigede Dam deformation monitoring system has been installed and started to operate, but there has been no evaluation of the geometry quality of control networks treated with IGS points for GNSS networks processing. Therefore, this study aims to evaluate the geometric quality of GNSS control networks on deformation monitoring of Jatigede Dam area. This research data includes the GNSS measurements of five CORS Jatigede Dam stations (R01, GG01, GCP04, GCP06, and GCP08) at doy 233 with network configuration scenarios of 12 IGS points on two quadrants (jat1), three quadrants (jat2), and four quadrants (jat3 and jat4). GNSS networks processing was done by GAMIT to obtain baseline vectors, followed by network processing usingparameter method of least squares adjustment. Networks processing with least squares adjustment aims to determine the most optimal  by precision and reliability criterion. Results of this study indicate that network configuration with 12 IGS stations in the two quadrants provides the most accurate coordinates of CORS dam stations. Standard deviations value of CORS station given by jat1 configuration are in the range of 2.7 up to 4.1 cm in X-Z components, whereas standard deviations in the Y component are in the range 5.8 up to 6.9 cm. An optimization assessment based on network strength, precision, and reliability factors shows optimum configuration by jat1.

Readjustment of Canadian Secondary Horizontal Control Networks

1978 ◽  
Vol 32 (4) ◽  
pp. 433-442
Author(s):  
C.D. McLellan ◽  
J.P. Henderson ◽  
J.D. Boal
Keyword(s):  
Least Squares ◽  
Approximate Method ◽  
Lower Order ◽  
Early Stage ◽  
Geodetic Survey ◽  
Secondary Control ◽  
Control Networks ◽  
Least Squares Adjustment ◽  
Secondary Networks ◽  
Horizontal Control

The readjustment of the Canadian secondary and lower order control networks is scheduled to take place in 1983 following the adoption of new primary framework values. Some 200 000 points are involved. 75 000 of which are the responsibility of the Geodetic Survey. These networks are to be evaluated, strengthened, densified and extended as necessary, prior to integration. The project will be done by regions defined, for the most part, by arcs of framework control. Secondary networks will be integrated with the framework by least squares adjustment; some lower order control may be recomputed by an approximate method. Considering the amount of secondary control to be readjusted, it is essential that agreement on the sharing of responsibilities between the federal and provincial agencies involved be reached at an early stage.

The Optimum Design of Geodetic Networks

1965 ◽  
Vol 19 (1) ◽  
pp. 90-91
Author(s):  
Michel Creusen ◽  
Harold J. Welch
Keyword(s):  
Computer Program ◽  
Least Squares ◽  
Optimum Design ◽  
Geodetic Network ◽  
University Of Michigan ◽  
Geodetic Networks ◽  
Least Squares Adjustment ◽  
The University

For a geodetic network, the least squares adjustment gives the best possible solution and an indication of the quality of that solution. On this basis, a computer program is being developed at the University of Michigan to determine the best and most economic configuration networks and the accuracies required in measuring.

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.

Experience with the Relay Procedure for Tuning Controllers in Automatic Control of Chlorination

1993 ◽  
Vol 28 (11-12) ◽  
pp. 257-261
Author(s):  
M. Truett Garrett ◽  
Zaki Ahmad ◽  
Shelly Young
Keyword(s):  
Wastewater Treatment ◽  
Automatic Control ◽  
Time Constant ◽  
Wastewater Treatment Plants ◽  
Relay Feedback ◽  
Quality Of Control ◽  
Incomplete Mixing ◽  
Long Time ◽  
Chlorine Demand

The recent requirements by U.S.E.P.A. for dechlorination and biomonitoring have increased the importance of automatic control of effluent chlorination in wastewater treatment plants. Difficulties with the Ziegler-Nichols controller tuning procedure were reported at the Kyoto Workshop, 1990. Problems are caused by the noise of incomplete mixing, a long time constant, and the disturbances of changing flow and chlorine demand. The Astrom-Hagglund relay feedback procedure provides acceptable control while data is logged to determine the controller constants. Experiences in using the procedure in existing facilities (not redesigning the mixing point) and the quality of control are presented.

scholarly journals Using Least-Squares Residuals to Assess the Stochasticity of Measurements—Example: Terrestrial Laser Scanner and Surface Modeling

2021 ◽  
Vol 5 (1) ◽  
pp. 59
Author(s):  
Gaël Kermarrec ◽  
Niklas Schild ◽  
Jan Hartmann
Keyword(s):  
Least Squares ◽  
Laser Scanner ◽  
Real Data ◽  
Point Clouds ◽  
Statistical Testing ◽  
Normal Vector ◽  
Engineering Structures ◽  
3D Point Clouds ◽  
Least Squares Adjustment ◽  
Correlation Parameters

Terrestrial laser scanners (TLS) capture a large number of 3D points rapidly, with high precision and spatial resolution. These scanners are used for applications as diverse as modeling architectural or engineering structures, but also high-resolution mapping of terrain. The noise of the observations cannot be assumed to be strictly corresponding to white noise: besides being heteroscedastic, correlations between observations are likely to appear due to the high scanning rate. Unfortunately, if the variance can sometimes be modeled based on physical or empirical considerations, the latter are more often neglected. Trustworthy knowledge is, however, mandatory to avoid the overestimation of the precision of the point cloud and, potentially, the non-detection of deformation between scans recorded at different epochs using statistical testing strategies. The TLS point clouds can be approximated with parametric surfaces, such as planes, using the Gauss–Helmert model, or the newly introduced T-splines surfaces. In both cases, the goal is to minimize the squared distance between the observations and the approximated surfaces in order to estimate parameters, such as normal vector or control points. In this contribution, we will show how the residuals of the surface approximation can be used to derive the correlation structure of the noise of the observations. We will estimate the correlation parameters using the Whittle maximum likelihood and use comparable simulations and real data to validate our methodology. Using the least-squares adjustment as a “filter of the geometry” paves the way for the determination of a correlation model for many sensors recording 3D point clouds.

scholarly journals Quality of Control in the Tavis–Cummings–Hubbard Model

2021 ◽  
Author(s):  
R. Düll ◽  
A. Kulagin ◽  
W. Lee ◽  
Yu. Ozhigov ◽  
H. Miao ◽  
...  
Keyword(s):  
Hubbard Model ◽  
Quality Of Control

Variable-Frequency Prony Method in the Analysis of Electrical Power Quality

2012 ◽  
Vol 19 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Jarosław Zygarlicki ◽  
Janusz Mroczka
Keyword(s):  
Least Squares ◽  
Power Quality ◽  
Electrical Power ◽  
Electric Energy ◽  
Variable Frequency ◽  
Prony Method ◽  
Analysis Window ◽  
Proposed Modification ◽  
Selection Of

Variable-Frequency Prony Method in the Analysis of Electrical Power QualityThe article presents a new modification of the the least squares Prony method. The so-called variable-frequency Prony method can be a useful tool for estimating parameters of sinusoidal components, which, in the analyzed signal, are characterized by time-dependent frequencies. The authors propose use of the presented method for testing the quality of electric energy. It allows observation of phenomena which, when using traditional methods, are averaged in the analysis window. The proposed modification of least squares Prony method is based on introduction and specific selection of a frequency matrix. This matrix represents frequencies of estimated components and their variability in time.

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