On the accuracy requirements of terrestrial laser scanning for solving engineering and geodetic tasks using BIM

2021 ◽  
Vol 974 (8) ◽  
pp. 2-12
Author(s):  
A.A. Sharafutdinova ◽  
M.J. Bryn
Keyword(s):  
Life Cycle ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Information Modeling ◽  
Digital Information ◽  
Mean Square ◽  
Technical Documentation ◽  
Accuracy Requirement ◽  
The Mean ◽  
Mean Square Errors

Terrestrial laser scanning and digital information modeling are increasingly practiced every year to solve application tasks at various stages of the industrial facility’s life cycle. In this regard, the task of formulating the requirements for the accuracy of performing terrestrial laser scanning for the subsequent forming digital information models becomes more and more calling. In this article we analyzed the types of engineering and geodetic works by which engineering tasks are solved at various stages of the industrial facility’s life cycle in order to create an accuracy requirement. An analysis of the regulatory and technical documentation that specifies doing these works was also made. Basing on it, the relationship between the measurement accuracy characteristics specified in the regulatory and technical documentation (design, construction and operational) and the mean square errors in determining the position of points is described. The authors propose a scheme for transition from the characteristics of the measurements accuracy to the mean square errors of determining the position of points for each type of engineering and geodetic work. The results of this study can be used at planning terrestrial laser scanning of industrial facilities. Basing on the above requirements for the accuracy of the geodetic work, it is possible to formulate a methodology for carrying out each stage of the TLS technological scheme.

scholarly journals THE EXPERIENCE IN USING LASER SCANNING AND BUILDING INFORMATION MODELING FOR ENGINEERING DATA MANAGEMENT DURING THE LIFE CYCLE OF AN INDUSTRIAL OBJECT

2021 ◽  
Vol 26 (1) ◽  
pp. 57-67
Author(s):  
Anzhelika A. Sharafutdinova ◽  
◽  
Michael Ja. Bryn ◽  
Keyword(s):  
Life Cycle ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Information Modeling ◽  
Technical Documentation ◽  
Existing Structures ◽  
Operation Process ◽  
Industrial Object ◽  
Building Information ◽  
Project Construction

An industrial object accumulates a great deal of information about its assets throughout its whole development period. This information is provided in the different drawings, passports, regulations, and other technical documentation. One of the common problems of most industrial objects is the disor-ganized storage of technical documentation on assets and its limited access to different industrial ser-vices. This greatly complicates the retrieval of information about the assets to ensure the steady opera-tion of the industrial object. As a consequence, one of the ongoing important tasks becomes the crea-tion of a unified source of up-to-date information about the object’s assets and the facilitation of the access to that data for all the participants of the project, construction, and operation process. Exactly these issues are tackled in the article alongside with the solutions based on using BIM and terrestrial laser scanning. This article also describes the types of BIM and detailed differences between them, the methods to form a BIM, as well as how the methods change at different stages of the life cycle. As well, the typology of tasks for which BIM solutions are applicable. TLS technology is described as a source of initial data for the formation of BIM. This article describes the results of the combined use of BIM and TLS at the stages of design, construction, and operation of an industrial object based on the implemented project. The article provides the result of clash detection in design documentation. The result of clash detection between designed and existing structures is also given. The article also provides the deviations at the construction stage of industrial objects, which were discovered. The ac-quired results demonstrated the effectiveness of using terrestrial laser scanning and BIM in engineering solutions.

scholarly journals Intelligent Calibration of Static FEA Computations Based on Terrestrial Laser Scanning Reference

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6439
Author(s):  
Wei Xu ◽  
Xiangyu Bao ◽  
Genglin Chen ◽  
Ingo Neumann
Keyword(s):  
Deep Learning ◽  
Laser Scanning ◽  
Short Term Memory ◽  
Terrestrial Laser Scanning ◽  
Monitoring Methods ◽  
Element Analysis ◽  
Threshold Control ◽  
The Mean ◽  
Structural Behaviors ◽  
Mean Square Errors

The demand for efficient and accurate finite element analysis (FEA) is becoming more prevalent with the increase in advanced calibration technologies and sensor-based monitoring methods. The current research explores a deep learning-based methodology to calibrate FEA results. The utilization of monitoring reference results from measurements, e.g., terrestrial laser scanning, can help to capture the actual features in the static loading process. We learn the deviation sequence results between the standard FEA computations with the simplified geometry and refined reference values by the long short-term memory method. The complex changing principles in different deviations are trained and captured effectively in the training process of deep learning. Hence, we generate the FEA sequence results corresponding to next adjacent loading steps. The final FEA computations are calibrated by the threshold control. The calibration reduces the mean square errors of the FEA future sequence results significantly. This strengthens the calibration depth. Consequently, the calibration of FEA computations with deep learning can play a helpful role in the prediction and monitoring problems regarding the future structural behaviors.

scholarly journals Realization of the Primary Terrestrial Reference Frame

1991 ◽  
Vol 127 ◽  
pp. 108-115
Author(s):  
W. Kosek ◽  
B. Kołaczek
Keyword(s):  
Reference Frame ◽  
Geographic Distribution ◽  
Terrestrial Reference Frame ◽  
Mean Square ◽  
Minimum Value ◽  
Collocation Points ◽  
Station Coordinates ◽  
The Mean ◽  
Transformation Parameters ◽  
Mean Square Errors

AbstractThe PTRF is based on 43 sites with 64 SSC collocation points with the optimum geographic distribution, which were selected from all stations of the ITRF89 according to the criterion of the minimum value of the errors of 7 parameters of transformation. The ITRF89 was computed by the IERS Terrestrial Frame Section in Institut Geographique National - IGN and contains 192 VLBI and SLR stations (points) with 119 collocation ones. The PTRF has been compared with the ITRF89. The errors of the 7 parameters of transformation between the PTRF and 18 individual SSC as well as the mean square errors of station coordinates are of the same order as those for the ITRF89. The transformation parameters between the ITRF89 and the PTRF are negligible and their errors are of the order of 3 mm.

Mathematical-Statistical Methods for the Analysis of Aerial Triangulation Adjustment Errors Using a Computer Program

1975 ◽  
Vol 29 (2) ◽  
pp. 175-188
Author(s):  
M. Mosaad Allam
Keyword(s):  
Computer Program ◽  
Frequency Interval ◽  
Mean Square ◽  
Fisher Criterion ◽  
Statistical Parameters ◽  
Sample Distribution ◽  
Development Section ◽  
The Mean ◽  
Kolmogorov Criterion ◽  
Mean Square Errors

In practice, photogrammetrists use a single statistic reliability interval criterion, based on the mean square errors, to judge the accuracy of adjustment of photogrammetric blocks. Even in some cases, if the practical and theoretical distributions of frequency interval agree, such a test does not make it possible to establish the closeness of their convergence nor the degree of their difference. In other words, to get a complete picture of the character of the distribution of errors in the adjusted photogrammetric blocks, it is insufficient to investigate any single statistic. In the Research and Development Section of the Topographical Survey Directorate, a computer program (SABA) has been designed to analyze the errors of photogrammetric block adjustments, compute various statistical parameters and check the sample distribution using Kolmogorov criterion. Based on the decision taken, the correspondence between the empirical and theoretical distribution series are checked using the criterion χ2. The program divides the adjusted block to make a comparative evaluation of accuracies in the different sub-blocks. In this case, in addition to Kolmogorov and χ2 tests, the program checks the reliability intervals of the means and mean square errors of the samples and uses Fisher criterion ‘F’ to check the hypothesis of the equality of dispersion. SABA is coded in Fortran IV and Compass for the CDC CYBER 74 and requires a central memory of 28K decimal works. SABA is the acronym for Statistical Analysis of Block Adjustment.

scholarly journals Using terrestrial laser scanning in inventorying of a hybrid constructed wetland system

2017 ◽  
Vol 76 (10) ◽  
pp. 2664-2671
Author(s):  
Radomir Obroślak ◽  
Andrzej Mazur ◽  
Krzysztof Jóźwiakowski ◽  
Oleksandr Dorozhynskyy ◽  
Antoni Grzywna ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Hot Spots ◽  
National Park ◽  
Laser Scanning ◽  
Treatment Plant ◽  
Terrestrial Laser Scanning ◽  
Technical Documentation ◽  
Education Centre ◽  
Quantitative Changes

Abstract The goal of this paper was to evaluate the possibility of using terrestrial laser scanning (TLS) for inventorying of a hybrid constructed wetland (CW) wastewater treatment plant. The object under study was a turtle-shaped system built in 2015 in Eastern Poland. Its main purpose is the treatment of wastewater from the Museum and Education Centre of Polesie National Park. The study showed that the CW system had been built in compliance with the technical documentation, as differences between values obtained from the object and those given in the design project (max. ± 20 cm for situation and ±5 cm for elevation) were within the range defined by the legislator. It was also shown that the results were sufficiently precise to be used for as-built surveying of the aboveground elements of the CW system. The TLS technique can also be employed to analyse quantitative changes in object geometry arising during long-term use (e.g. landmass slides or erosion), the identification of which can help in selecting the hot-spots at risk of damage and thus restore the object to its original state as well as prevent new changes.

Extrapolation Problem for Continuous Time Periodically Correlated Isotropic Random Fields

2017 ◽  
Vol 19 ◽  
pp. 1-23
Author(s):  
Iryna Golichenko ◽  
Oleksand Masyutka ◽  
Mikhail Moklyachuk
Keyword(s):  
Random Field ◽  
Spectral Characteristics ◽  
Mean Square ◽  
Spectral Densities ◽  
Optimal Linear ◽  
Extrapolation Problem ◽  
Time Argument ◽  
The Mean ◽  
Mean Square Errors ◽  
Isotropic Random

The problem of optimal linear estimation of functionals depending on the unknown values of a random fieldζ(t,x), which is mean-square continuous periodically correlated with respect to time argumenttє R and isotropic on the unit sphere Sn with respect to spatial argumentxєSn. Estimates are based on observations of the fieldζ(t,x) +Θ(t,x) at points (t,x) :t< 0;xєSn, whereΘ(t,x) is an uncorrelated withζ(t,x) random field, which is mean-square continuous periodically correlated with respect to time argumenttє R and isotropic on the sphereSnwith respect to spatial argumentxєSn. Formulas for calculating the mean square errors and the spectral characteristics of the optimal linear estimate of functionals are derived in the case of spectral certainty where the spectral densities of the fields are exactly known. Formulas that determine the least favourable spectral densities and the minimax (robust) spectral characteristics are proposed in the case where the spectral densities are not exactly known while a class of admissible spectral densities is given.

Application of on-line Adaptive Weighted Fusion in Mine Gas Measurement System

2012 ◽  
Vol 239-240 ◽  
pp. 1395-1398
Author(s):  
Yan Ju Wang ◽  
Li Kun Yang ◽  
Yu Tian Wang
Keyword(s):  
Measurement System ◽  
Mean Square ◽  
Least Mean Square ◽  
Fusion Algorithm ◽  
Important Indicator ◽  
Weighted Fusion ◽  
Environmental Monitoring System ◽  
The Mean ◽  
Mine Gas ◽  
Mean Square Errors

In mine environmental monitoring system, the concentration of mine gas is an important indicator. Aiming at the redundant information from multi-gas sensors in the measurement system, adaptive weighted fusion algorithm was presented. Using this algorithm, it was unnecessary to be aware of any pre-defined knowledge about these datas measured by the sensors. That the algorithm could adjust the fused sensor’s weight in time according to the variation in sensors’ variances makes the mean square error minimal. It was also proved theoretically that this fusion algorithm is linear and unbiased, in respect of the least mean square errors. Simulation results showed that this fusion algorithm is effective and the result of fused data is superior to the mean estimate algorithm in respect of accuracy and fault tolerance.

scholarly journals Assessing Vehicle Profiling Accuracy of Handheld LiDAR Compared to Terrestrial Laser Scanning for Crash Scene Reconstruction

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8076
Author(s):  
Jairaj Desai ◽  
Jidong Liu ◽  
Robert Hainje ◽  
Robert Oleksy ◽  
Ayman Habib ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Measurement Accuracy ◽  
Electronic Devices ◽  
Terrestrial Laser Scanning ◽  
Light Detection And Ranging ◽  
Mean Square ◽  
Profiling Techniques ◽  
Subsequent Measurement ◽  
Maximum Root ◽  
Handheld Electronic Devices

Forensic crash investigation often requires developing detailed profiles showing the location and extent of vehicle damage to identify impact areas, impact direction, deformation, and estimated vehicle speeds at impact. Traditional damage profiling techniques require extended and comprehensive setups for mapping and measurement that are quite labor- and time-intensive. Due to the time involved, this damage profiling is usually done in a remote holding area after the crash scene is cleared. Light detection and ranging (LiDAR) scanning technology in consumer handheld electronic devices, such as smartphones and tablets, holds significant potential for conducting this damage profile mapping in just a few minutes, allowing the mapping to be conducted at the scene before the vehicle(s) are moved. However, there is limited research and even scarcer published literature on field procedures and/or accuracy for these emerging smartphones and tablets with LiDAR. This paper proposes a methodology and subsequent measurement accuracy comparisons for survey-grade terrestrial laser scanning (TLS) and handheld alternatives. The maximum root mean square error (RMSE) obtained for profile distance between handheld (iPad) and survey-grade TLS LiDAR scans for a damaged vehicle was observed to be 3 cm, a level of accuracy that is likely sufficient and acceptable for most forensic studies.

scholarly journals A Novel Approach for the Detection of Standing Tree Stems from Plot-Level Terrestrial Laser Scanning Data

2019 ◽  
Vol 11 (2) ◽  
pp. 211 ◽  
Author(s):  
Wuming Zhang ◽  
Peng Wan ◽  
Tiejun Wang ◽  
Shangshu Cai ◽  
Yiming Chen ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Natural Forests ◽  
Individual Tree ◽  
Urban Scenes ◽  
Novel Approach ◽  
Wide Range ◽  
Standing Trees ◽  
The Mean ◽  
Point Cloud Classification

Tree stem detection is a key step toward retrieving detailed stem attributes from terrestrial laser scanning (TLS) data. Various point-based methods have been proposed for the stem point extraction at both individual tree and plot levels. The main limitation of the point-based methods is their high computing demand when dealing with plot-level TLS data. Although segment-based methods can reduce the computational burden and uncertainties of point cloud classification, its application is largely limited to urban scenes due to the complexity of the algorithm, as well as the conditions of natural forests. Here we propose a novel and simple segment-based method for efficient stem detection at the plot level, which is based on the curvature feature of the points and connected component segmentation. We tested our method using a public TLS dataset with six forest plots that were collected for the international TLS benchmarking project in Evo, Finland. Results showed that the mean accuracies of the stem point extraction were comparable to the state-of-art methods (>95%). The accuracies of the stem mappings were also comparable to the methods tested in the international TLS benchmarking project. Additionally, our method was applicable to a wide range of stem forms. In short, the proposed method is accurate and simple; it is a sensible solution for the stem detection of standing trees using TLS data.

Huit campagnes d’observations de Saturne a l’Astrolabe Danjon a San Fernando

1978 ◽  
Vol 48 ◽  
pp. 471-478
Author(s):  
M. Sanchez
Keyword(s):  
Theoretical Development ◽  
Mean Square ◽  
Mean Values ◽  
San Fernando ◽  
The Mean ◽  
Mean Square Errors ◽  
Right Ascension

Abstract:This paper contains an analysis of Saturn observations with Danjon astrolabe at San Fernando. These observations were obtained during eight winter campaigns (1970-1978). Table 1 gives the mean values for each of the quantities Δα and Δδ (astrolabe - American Ephemeris) and the mean square errors. Figure 1 to 8 shows the results (right ascension and declination) and the corresponding smoothing curves. The accuracy of these curves is also given in table 1. The analysis of the values Δα and Δδ seem to show that there are differences, between the theoretical development of ephemeris and the observations, of periodical character.

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