Analysis of power lines span geometry based on TLS measurements

The inventory measurements of utility infrastructure are crucial issues in the field of engineering geodesy. Secure usage of power lines requires to monitor their geometry. According to classical approach to measurements of geometry of overhead power lines, it usually allows only to measure directly. Geodetic methods cannot be applied due to measuring limitations (lack of an appropriate area to conduct a measurement). Currently in engineering geodesy it is becoming more common to use methods of laser scanning as well as Unmanned Aerial Photogrammetric Survey. In the Paper, the procedure of determining of an overhead power line’s geometry is presented on the example of an one span measured with Terrestrial Laser Scanning methods. Field measurements were conducted by using laser scanner. Afterwards the point cloud was processed in order to receive the geometry of conductor. Finally, results were presented is tabular and graphic form.

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An Alternative Method for Long-Term Monitoring of Thai Historic Pagodas Based on Terrestrial Laser Scanning Data: A Case Study of Wat Krachee in Ayutthaya

Advances in Civil Engineering ◽

10.1155/2021/5587046 ◽

2021 ◽

Vol 2021 ◽

pp. 1-17

Author(s):

Peerasit Mahasuwanchai ◽

Chainarong Athisakul ◽

Phasu Sairuamyat ◽

Weerachart Tangchirapat ◽

Sutat Leelataviwat ◽

...

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Laser Scanner ◽

Terrestrial Laser Scanning ◽

Point Cloud Data ◽

Cloud Data ◽

Long Term Monitoring ◽

Term Monitoring

This article presents an alternative method for the long-term monitoring of heritage pagodas in Thailand. In this method, terrestrial laser scanning (TLS) is used in combination with permanent survey markers. The Wat (temple) Krachee in the Ayutthaya Province of Thailand was chosen as a case study. This temple has several fantastic elements, including an inverted bell-shaped pagoda, two intertwined trees growing within it, and a chamber inside the pagoda. The preservation team working on the pagoda encountered a challenging problem and faced a decision to trim or not to trim the tree since it has a long-term effect on the pagoda’s structural stability. A high-accuracy terrestrial laser scanner was used to collect three-dimensional point cloud data. Permanent survey markers were constructed in 2018 to be used in long-term monitoring. The 3D surveying of the temple and the monitoring of the pagoda were carried out in five sessions during a period ending in 2020. A point cloud data analysis was performed to obtain the current dimensions, a displacement analysis, and the pagoda leaning angle. The results revealed that the terrestrial laser scanner is a high-performance piece of equipment offering efficient evaluation and long-term monitoring. However, in this study, permanent survey markers were also required as a benchmark for constraining each monitoring session. The 3D point cloud models could be matched with the assumption model elements to evaluate the damaged shape and to determine the original form. The significant elements of an inverted bell-shaped pagoda were investigated. Trimming the tree was found to cause the leaning angle of the pagoda to decrease. An equation was developed for predicting the leaning angle of the Wat Krachee pagoda for preservation and restoration planning in the future. From the results of this study, it is recommended that periodic monitoring should continue in order to preserve Thai pagodas in their original forms.

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A Laser Scanning System for Sag Detection on the Overhead Power Lines: In Field Measurements

Lecture Notes in Electrical Engineering - Sensors ◽

10.1007/978-1-4614-3860-1_55 ◽

2013 ◽

pp. 311-314

Author(s):

Elena Golinelli ◽

Umberto Perini ◽

Franco Barberis ◽

Sergio Musazzi

Keyword(s):

Laser Scanning ◽

Field Measurements ◽

Power Lines ◽

Scanning System ◽

Overhead Power Lines ◽

Laser Scanning System

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Study of the Application of Terrestrial Laser Scanning for Identification of Pathologies in Concrete Structures

10.21203/rs.3.rs-1001215/v1 ◽

2021 ◽

Author(s):

Sergio Orlando Antoun Netto ◽

Lucas Pires Chagas Ferreira de Carvalho ◽

Ana Waldila de Queiroz Ramiro Reis ◽

Leonardo Vieira Barbalho ◽

Lucas de Campos Rodrigues

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Three Dimensional ◽

Laser Scanner ◽

Concrete Structures ◽

Terrestrial Laser Scanning ◽

Color Data ◽

Definition Of ◽

The City

Abstract Laser scanning enhances classic field surveys. The terrestrial laser scanner is a versatile device with applications in various areas of knowledge, which uses remote sensing fundamentals to determine point coordinates. It is a remote, active, noninvasive, nondestructive and high-precision technique to capture reality that records from thousands to millions of points per second in a detailed representation of the situation called a point cloud. The surveys are performed along the object of interest in a process called scanning, which has as its gross product a dense cloud of three-dimensional points of the scanned object. This point cloud stores information about the object’s geometry, return pulse intensity, and point color data. As a way of extending the uses of terrestrial laser scanning, this work studies the application of this method in civil engineering, through the identification of pathologies in reinforced concrete structures, aiming to show how geoinformation can be employed in this area. To this end, a case study of the São Cristóvão Viaduct was conducted in the city of Rio de Janeiro. This study included definition of the site of analysis; planning and execution of the field survey to collect raw data; processing of the point cloud; and generation of a three-dimensional surface for global visualization of the structure and identification of pathological manifestations and the regions where they were observed. Concrete structures in general are affected by various external factors, such as weather and anthropogenic actions, which contribute to their wear.

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BOAT-BASED MOBILE LASER SCANNING FOR SHORELINE MONITORING OF LARGE LAKES

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b2-2021-759-2021 ◽

2021 ◽

Vol XLIII-B2-2021 ◽

pp. 759-762

Author(s):

D. Schneider ◽

R. Blaskow

Keyword(s):

Water Body ◽

Point Cloud ◽

Laser Scanning ◽

Laser Scanner ◽

Terrestrial Laser Scanning ◽

Water Bodies ◽

Three Dimensions ◽

Shore Protection ◽

Large Lakes ◽

Protection Measures

Abstract. In many applications, it is necessary to measure the shore areas of water bodies in three dimensions, for example for the planning of shore protection measures or regularly for water body monitoring. The complete recording of long shorelines can be very time-consuming with conventional methods. This paper presents the surveying of two lakes using a mobile laser scanner system. In order to close non-visible areas, the measurement was supplemented with terrestrial laser scanning and with UAV-supported photogrammetric methods. The result is an almost complete point cloud of the shoreline, each more than 8 km long, with a point spacing of a few millimetres.

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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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Regional Modeling of Forest Fuels and Structural Attributes Using Airborne Laser Scanning Data in Oregon

Remote Sensing ◽

10.3390/rs13020261 ◽

2021 ◽

Vol 13 (2) ◽

pp. 261

Author(s):

Francisco Mauro ◽

Andrew T. Hudak ◽

Patrick A. Fekety ◽

Bryce Frank ◽

Hailemariam Temesgen ◽

...

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Field Measurements ◽

Point Clouds ◽

Semiparametric Models ◽

Airborne Laser Scanning ◽

Parametric Models ◽

Fuel Load ◽

Forest Fuels ◽

Airborne Laser

Airborne laser scanning (ALS) acquisitions provide piecemeal coverage across the western US, as collections are organized by local managers of individual project areas. In this study, we analyze different factors that can contribute to developing a regional strategy to use information from completed ALS data acquisitions and develop maps of multiple forest attributes in new ALS project areas in a rapid manner. This study is located in Oregon, USA, and analyzes six forest structural attributes for differences between: (1) synthetic (i.e., not-calibrated), and calibrated predictions, (2) parametric linear and semiparametric models, and (3) models developed with predictors computed for point clouds enclosed in the areas where field measurements were taken, i.e., “point-cloud predictors”, and models developed using predictors extracted from pre-rasterized layers, i.e., “rasterized predictors”. Forest structural attributes under consideration are aboveground biomass, downed woody biomass, canopy bulk density, canopy height, canopy base height, and canopy fuel load. Results from our study indicate that semiparametric models perform better than parametric models if no calibration is performed. However, the effect of the calibration is substantial in reducing the bias of parametric models but minimal for the semiparametric models and, once calibrations are performed, differences between parametric and semiparametric models become negligible for all responses. In addition, minimal differences between models using point-cloud predictors and models using rasterized predictors were found. We conclude that the approach that applies semiparametric models and rasterized predictors, which represents the easiest workflow and leads to the most rapid results, is justified with little loss in accuracy or precision even if no calibration is performed.

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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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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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