scholarly journals Application of statistical test on determining the unstable points in the basic network of horizontal displacement monitoring

2021 ◽  
Vol 62 (1) ◽  
pp. 35-41
Author(s):  
Khanh Quoc Pham ◽  
Keyword(s):  
Hydroelectric Plant ◽  
Hypothesis Test ◽  
Control Point ◽  
Horizontal Displacement ◽  
Test Method ◽  
Reference Network ◽  
Control Points ◽  
Displacement Monitoring ◽  
Local Statistics ◽  
Global Statistics

The paper represents the hypothesis test method that can determine the instability control points of the reference network in the displacement of construction. Regarding data processing in displacement monitoring, the detection and modification for instability points is an important task because this affects the computation of the displacement of monitoring points. This method has been applied in many countries over the world but not in Vietnam, and it is processed through two steps including the global statistics test and local statistics test. The global statistics test is to identify whether a control point is stable or not. The local statistics test based on the division of groups is to find the unstable control points exactly. Experimental computation is carried out in two monitoring cycles at Hoa Binh hydroelectric plant. In this experiment, this algorithm detected two unstable points among six control points. This result is in agreement with the result that is solved by Vietnam’s construction standard of TCVN 9399:2012. In conclusion, the hypothesis test method completely can apply in real geodetic production in Vietnam.

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 PENGARUH MODEL QUANTUM TEACHING BERBASIS PENDIDIKAN KARAKTER TERHADAP KOMPETENSI PENGETAHUAN IPA SISWA KELAS V SD GUGUS DEWI SARTIKA DENPASAR TIMUR TAHUN AJARAN 2017/2018

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Ni KomangMega Lestari
Keyword(s):  
Character Education ◽  
Hypothesis Test ◽  
Test Method ◽  
Control Group ◽  
Teaching Model ◽  
Control Group Design ◽  
Significance Level ◽  
Model Base ◽  
5Th Grade ◽  
Academic Year

This research aims to know the effect of quantum teaching model base character education towards science competency knowledge in 5th grade students of Gugus Dewi Sartika East Denpasar academic year 2017/2018. This study was an experiment with quasy experiment design using the Non-Equivalent Control Group Design. The population of this research is all 5th grade of Gugus Dewi Sartika East Denpasar amounting to 328 students. Sample were taken by random sampling technique. The sample of this research is 5th A grade in SDN  10 Kesiman amount 42 students as the experiment group and 5th B grade in SDN 3 Kesiman amount 53 student as the control group. The data were collected using the test method in the form of a standard multiple choice objective test. The data were analyzed using descriptive statistic and inferential in shape gain score from science competency knowledge. The result if data analysis obtained mean of gain skor from experiment group 16X"> =0,34 > 16X"> =0,25 control group. From the hypothesis test using t-test while at 5% significance level and df 83 obtained thitung =3,214 > ttabel=2,000. Based on these result can be concluded that quantum teaching model base character education influence of science competency knowledge of 5th grade students SD Gugus Dewi Sartika East Denpasar academic year 2017/2018.

scholarly journals Analysis of the Effect of Different Combinations of Observation Satellites on the Resolving Accuracy of GNSS Observation Data

2020 ◽  
Vol 206 ◽  
pp. 03025
Author(s):  
Junze Wang ◽  
Maohua Yao ◽  
Wenting Zhou ◽  
Xiangping Chen
Keyword(s):  
Measurement Accuracy ◽  
Control Point ◽  
Satellite System ◽  
Base Stations ◽  
Observation Data ◽  
Control Points ◽  
Level Control ◽  
Satellite Systems ◽  
Beidou Navigation Satellite System ◽  
Stable Measurement

In this paper, 24 C-level control points under different terrain conditions were selected to be the testing points. The binary-satellite system (GPS+GLONASS) and the triple-satellite system with BeiDou Navigation Satellite System (BDS) (BDS+GPS+GLONASS) were adopted for static measurement; and the observation data from BeiDou Ground-based Augumentation System (GBAS) base stations in Guangxi were collected for solution. By comparing the residuals of GPS tri-dimensional baseline vectors and the internal accord accuracy of each control point under the binary and triple-satellite systems, the effect of data collected by different satellite systems under different terrain conditions on measurement accuracy was studied. According to the results, (1) the triple-satellite system with BDS showed more stable measurement accuracy; (2) in plane, the two systems were of equivalent measurement accuracy in mountainous and flat areas; in elevation, the triple-satellite system showed higher and more stable measurement accuracy.

scholarly journals MULTIRESOLUTION CONTROL OF CURVES AND SURFACES WITH A SELF-SIMILAR MODEL

Fractals ◽  
2010 ◽  
Vol 18 (03) ◽  
pp. 271-286 ◽  
Author(s):  
HOUSSAM HNAIDI ◽  
ERIC GUÉRIN ◽  
SAMIR AKKOUCHE
Keyword(s):  
Wavelet Transform ◽  
Control Point ◽  
Iterated Function Systems ◽  
Control Points ◽  
Similar Model ◽  
Surface Theory ◽  
Curves And Surfaces ◽  
Iterated Function ◽  
Resolution Level ◽  
Self Similar

This paper presents two self-similar models that allow the control of curves and surfaces. The first model is based on IFS (Iterated Function Systems) theory and the second on subdivision curve and surface theory. Both of these methods employ the detail concept as in the wavelet transform, and allow the multiresolution control of objects with control points at any resolution level.In the first model, the detail is inserted independently of control points, requiring it to be rotated when applying deformations. In contrast, the second method describes details relative to control points, allowing free control point deformations.Modeling examples of curves and surfaces are presented, showing manipulation facilities of the models.

Corner Reflector Network as a Geodetic Reference for Landslide Monitoring via InSAR Time Series: Case Study from Slovakia

2021 ◽  
Author(s):  
Richard Czikhardt ◽  
Juraj Papco ◽  
Peter Ondrejka ◽  
Peter Ondrus ◽  
Pavel Liscak
Keyword(s):  
Time Series ◽  
Horizontal Displacement ◽  
Terrestrial Reference Frame ◽  
Sar Interferometry ◽  
Global Navigation Satellite Systems ◽  
Reference Network ◽  
Landslide Monitoring ◽  
First Order ◽  
Order Estimation ◽  
Better Than

<p>SAR interferometry (InSAR) is inherently a relative geodetic technique requiring one temporal and one spatial reference to obtain the datum-free estimates on millimetre-level displacements within the network of radar scatterers. To correct the systematic errors, such as the varying atmospheric delay, and solve the phase ambiguities, it relies on the first-order estimation network of coherent point scatterers (PS).</p><p>For vegetated and sparsely urbanized areas, commonly affected by landslides in Slovakia, it is often difficult to construct a reliable first-order estimation network, as they lack the PS. Purposedly deploying corner reflectors (CR) at such areas strengthens the estimation network and, if these CR are collocated with a Global Navigation Satellite Systems (GNSS), they provide an absolute geodetic reference to a well-defined terrestrial reference frame (TRF), as well as independent quality control.</p><p>For landslides, line-of-sight (LOS) InSAR displacements can be difficult to interpret. Using double CR, i.e. two reflectors for ascending/descending geometries within a single instrument, enables the assumption-less decomposition of the observed cross-track LOS displacements into the vertical and the horizontal displacement components.</p><p>In this study, we perform InSAR analysis on the one-year of Sentinel-1 time series of five areas in Slovakia, affected by landslides. 24 double back-flipped trihedral CR were carefully deployed at these sites to form a reference network, guaranteeing reliable displacement information over the critical landslide zones. To confirm the measurement quality, we show that the temporal average Signal-to-Clutter Ratio (SCR) of the CR is better than 20 dB. The observed CR motions in vertical and east-west directions vary from several millimetres up to 3 centimetres, with average standard deviation better than 0.5 mm.<br>Repeated GNSS measurements of the CR confirm the displacement observed by the InSAR, improve the positioning precision of the nearby PS, and attain the transformation into the national TRF.</p>

Smoothness of C-Bezier Curves

2000 ◽  
Author(s):  
Manhong Wen ◽  
Kwun-Lon Ting
Keyword(s):  
Shape Control ◽  
Control Point ◽  
Design Procedure ◽  
Design Parameters ◽  
Control Points ◽  
Bezier Curves ◽  
Bézier Curves ◽  
Point Distribution ◽  
G1 Continuity ◽  
G2 Continuity

Abstract This paper presents G1 and G2 continuity conditions of c-Bezier curves. It shows that the collinear condition for G1 continuity of Bezier curves is generally no longer necessary for c-Bezier curves. Such a relaxation of constraints on control points is beneficial from the structure of c-Bezier curves. By using vector weights, each control point has two extra free design parameters, which offer the probability of obtaining G1 and G2 continuity by only adjusting the weights if the control points are properly distributed. The enlargement of control point distribution region greatly simplifies the design procedure to and enhances the shape control on constructing composite curves.

G1 Continuity of C-Bezier Rectangular Surfaces

2000 ◽  
Author(s):  
Manhong Wen ◽  
Kwun-Lon Ting
Keyword(s):  
Control Point ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Design Parameters ◽  
Control Points ◽  
Bézier Surfaces ◽  
G1 Continuity ◽  
Bezier Surfaces ◽  
Necessary And Sufficient

Abstract This paper probes G1 continuity between two adjacent c-Bezier rectangular patches. The necessary and sufficient conditions are derived. It shows that the coplanar condition for G1 continuity of two adjacent Bezier patches is not necessary for c-Bezier patches. Such a relaxation of constraints on control points is beneficial from vector weights of c-Bezier surfaces, which leads to two extra free design parameters for each control point. C-Bezier surfaces offer the possibility of obtaining G1 continuity by just adjusting the weights, which greatly simplifies the design to construct composite surfaces.

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