A NEW METHOD FOR DETERMINING THE DEFORMATION MONITORABLE INDICATOR OF POINT CLOUD

With the continuous development of the terrestrial laser scanning (TLS) technique, the precision of the laser scanning has been improved which makes it possible that TLS could be used for high-precision deformation monitoring. A deformation monitorable indicator (DMI) should be determined to distinguish the deformation from the error of point cloud and plays an important role in the deformation monitoring using TLS. After the DMI determined, a scheme of the deformation monitoring case could be planned to choose a suitable instrument, set up a suitable distance and sampling interval. In this paper, the point error space and the point cloud error space are modelled firstly based on the point error ellipsoid. Secondly, the actual point error is derived by the relationship between the actual point cloud error space and the point error space. Then, the DMI is determined using the actual point error. Finally, two sets of experiments is carried out and the feasibility of the DMI is proved.

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Application of the Terrestrial Laser Scanning in Slope Deformation Monitoring: Taking a Highway Slope as an Example

Applied Sciences ◽

10.3390/app10082808 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2808 ◽

Cited By ~ 1

Author(s):

Chao Yin ◽

Haoran Li ◽

Zhinan Hu ◽

Ying Li

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Deformation Monitoring ◽

Slope Deformation ◽

Model Parameters ◽

Feature Points ◽

Registration Method ◽

Icp Algorithm ◽

Fine Registration

Slope deformation monitoring is the prerequisite for disaster risk assessment and engineering control. Terrestrial laser scanning (TLS) is highly applicable to this field. Coarse registration method of point cloud based on scale-invariant feature transform (SIFT) feature points and fine registration method based on the k-dimensional tree (K-D tree) improved iterative closest point (ICP) algorithm were proposed. The results show that they were superior to other algorithms (such as speeded-up robust features (SURF) feature points, Harris feature points, and Levenberg-Marquardt (LM) improved ICP algorithm) when taking the Stanford Bunny as an example, and had high applicability in coarse and fine registration. In order to integrate the advantages of point measurement and surface measurement, an improved point cloud comparison method was proposed and the optimal model parameters were determined through model tests. A case study was conducted on the left side of the K146 + 150 point at S236 Boshan section, Shandong Province, and research results show that from 14 August 2018 and 9 November 2019, the overall deformation of the slope was small with a maximum value of 0.183 m, and the slope will continue to maintain a stable state without special inducing factors such as earthquake, heavy rainfall and artificial excavation.

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Systematic Approach for Tunnel Deformation Monitoring with Terrestrial Laser Scanning

Remote Sensing ◽

10.3390/rs13173519 ◽

2021 ◽

Vol 13 (17) ◽

pp. 3519

Author(s):

Dongfeng Jia ◽

Weiping Zhang ◽

Yanping Liu

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

High Accuracy ◽

Deformation Monitoring ◽

Reference Plane ◽

Shield Tunnel ◽

Cloud Processing ◽

Point Cloud Processing

The use of terrestrial laser scanning (TLS) point clouds for tunnel deformation measurement has elicited much interest. However, general methods of point-cloud processing in tunnels are still under investigation, given the high accuracy and efficiency requirements in this area. This study discusses a systematic method of analyzing tunnel deformation. Point clouds from different stations need to be registered rapidly and with high accuracy before point-cloud processing. An orientation method of TLS in tunnels that uses a positioning base made in the laboratory is proposed for fast point-cloud registration. The calibration methods of the positioning base are demonstrated herein. In addition, an improved moving least-squares method is proposed as a way to reconstruct the centerline of a tunnel from unorganized point clouds. Then, the normal planes of the centerline are calculated and are used to serve as the reference plane for point-cloud projection. The convergence of the tunnel cross-section is analyzed, based on each point cloud slice, to determine the safety status of the tunnel. Furthermore, the results of the deformation analysis of a particular shield tunnel site are briefly discussed.

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Revealing Changes in the Stem Form and Volume Allocation in Diverse Boreal Forests Using Two-Date Terrestrial Laser Scanning

Forests ◽

10.3390/f12070835 ◽

2021 ◽

Vol 12 (7) ◽

pp. 835

Author(s):

Ville Luoma ◽

Tuomas Yrttimaa ◽

Ville Kankare ◽

Ninni Saarinen ◽

Jiri Pyörälä ◽

...

Keyword(s):

Tree Growth ◽

Point Cloud ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Point Clouds ◽

Stem Volume ◽

Accurate Information ◽

Stem Form ◽

Monitoring Period ◽

Significant Difference

Tree growth is a multidimensional process that is affected by several factors. There is a continuous demand for improved information on tree growth and the ecological traits controlling it. This study aims at providing new approaches to improve ecological understanding of tree growth by the means of terrestrial laser scanning (TLS). Changes in tree stem form and stem volume allocation were investigated during a five-year monitoring period. In total, a selection of attributes from 736 trees from 37 sample plots representing different forest structures were extracted from taper curves derived from two-date TLS point clouds. The results of this study showed the capability of point cloud-based methods in detecting changes in the stem form and volume allocation. In addition, the results showed a significant difference between different forest structures in how relative stem volume and logwood volume increased during the monitoring period. Along with contributing to providing more accurate information for monitoring purposes in general, the findings of this study showed the ability and many possibilities of point cloud-based method to characterize changes in living organisms in particular, which further promote the feasibility of using point clouds as an observation method also in ecological studies.

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Seasonal deformation monitoring over thermokarst landforms using terrestrial laser scanning in Northeastern Qinghai-Tibetan Plateau

International Journal of Applied Earth Observation and Geoinformation ◽

10.1016/j.jag.2021.102501 ◽

2021 ◽

Vol 103 ◽

pp. 102501

Author(s):

Wen Zhong ◽

Tingjun Zhang ◽

Jie Chen ◽

Jianguo Shang ◽

Shufa Wang ◽

...

Keyword(s):

Tibetan Plateau ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Deformation Monitoring

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THE USING OF TERRESTRIAL LASER (POINT CLOUD) SCANNING TECHNOLOGIES ON URBAN SCALE: EXAMPLE OF THE HISTORICAL URBAN TEXTURE OF LAPSEKİ

INTERNATIONAL REFEREED JOURNAL OF DESIGN AND ARCHITECTURE ◽

10.17365/tmd.2021.turkey.23.03 ◽

2021 ◽

Vol 0 (23) ◽

pp. 0-0

Author(s):

Hatice Çiğdem ZAĞRA ◽

Sibel ÖZDEN

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Three Dimensional ◽

Terrestrial Laser Scanning ◽

Traditional Methods ◽

Life Project ◽

Three Dimensional Models ◽

Architectural Restoration ◽

Cloud Technologies ◽

Orthophoto Images

Aim: This study aims to comparatively evaluate the use potential of orthophoto images obtained by terrestrial laser scanning technologies on an urban scale through the "Old Lapseki Finds Life Project" prepared using terrestrial laser scanning technologies and the "Enez Historical City Square Project" prepared using traditional methods. Method: In the study, street improvement projects of 29.210 m2 Lapseki and 29.214 m2 Enez city designed on an urban scale were evaluated and compared with descriptive statistics based on different parameters. Results: In the study, it has been determined that terrestrial laser (point cloud) technologies are 99,9% accurate when compared to traditional methods, save time by 83,08% and reduce workforce by 80%. In addition, it has been determined that terrestrial laser scanning technologies accelerate project processes compared to traditional methods. Conclusion: In this study, the use of laser scanning technologies, which are basically reverse engineering applications, in architectural restoration projects, determination of the current situation and damage, architectural documentation of structures and preparation of three-dimensional models, in terms of efficiency in survey studies are evaluated. It has been observed that orthophoto images obtained by terrestrial laser scanning technologies in architectural relief-restoration-restitution projects have potentials' worth using in different stages of the project.

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Automated terrestrial laser scanning with near-real-time change detection – monitoring of the Séchilienne landslide

Earth Surface Dynamics ◽

10.5194/esurf-5-293-2017 ◽

2017 ◽

Vol 5 (2) ◽

pp. 293-310 ◽

Cited By ~ 24

Author(s):

Ryan A. Kromer ◽

Antonio Abellán ◽

D. Jean Hutchinson ◽

Matt Lato ◽

Marie-Aurelie Chanut ◽

...

Keyword(s):

Change Detection ◽

Real Time ◽

Laser Scanning ◽

Terrestrial Laser Scanning ◽

Cost Effective ◽

Deformation Monitoring ◽

Time Change ◽

High Temporal Resolution ◽

Atmospheric Conditions ◽

Detection Processing

Abstract. We present an automated terrestrial laser scanning (ATLS) system with automatic near-real-time change detection processing. The ATLS system was tested on the Séchilienne landslide in France for a 6-week period with data collected at 30 min intervals. The purpose of developing the system was to fill the gap of high-temporal-resolution TLS monitoring studies of earth surface processes and to offer a cost-effective, light, portable alternative to ground-based interferometric synthetic aperture radar (GB-InSAR) deformation monitoring. During the study, we detected the flux of talus, displacement of the landslide and pre-failure deformation of discrete rockfall events. Additionally, we found the ATLS system to be an effective tool in monitoring landslide and rockfall processes despite missing points due to poor atmospheric conditions or rainfall. Furthermore, such a system has the potential to help us better understand a wide variety of slope processes at high levels of temporal detail.

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Network method for deformation analysis of three-dimensional point cloud with terrestrial laser scanning sensor

International Journal of Distributed Sensor Networks ◽

10.1177/1550147718814139 ◽

2018 ◽

Vol 14 (11) ◽

pp. 155014771881413 ◽

Cited By ~ 8

Author(s):

Xiangyang Xu ◽

Hao Yang

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Three Dimensional ◽

Terrestrial Laser Scanning ◽

Deformation Analysis ◽

Transverse Displacement ◽

Displacement Analysis ◽

Accuracy Measurement ◽

Network Method ◽

Displacement Information

The complexity of structural materials is increasing the importance of the technology for high accuracy measurement. How to obtain the displacement information of structural feature points accurately and efficiently is the key issue of deformation analysis. In this article, displacement analysis of a composite arched structure is investigated based on the terrestrial laser scanning technique. A new method based on the measured point cloud is proposed to analyze the displacement of surficial points, resulting in not only the displacement size but also the displacement direction. The innovation lies in extracting the displacement information with a network and remapped point cloud, which is called the network method. The displacement map obtained demonstrates that the transverse displacement in the experiment plays an important role in the safety of the structure, which could not be observed and obtained by the surface approximation method. Therefore, the panorama- and pointwise displacement analysis technologies contribute to ensure the safety of increasingly complex constructions.

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