scholarly journals Rigorous error propagation for terrestrial laser scanning with application to snow volume uncertainty

2015 ◽  
Vol 61 (230) ◽  
pp. 1147-1158 ◽  
Author(s):  
Preston J. Hartzell ◽  
Peter J. Gadomski ◽  
Craig L. Glennie ◽  
David C. Finnegan ◽  
Jeffrey S. Deems
Keyword(s):  
Error Propagation ◽  
Point Cloud ◽  
Laser Scanning ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Terrestrial Laser Scanning ◽  
Limiting Factor ◽  
Random Errors ◽  
Distance Measurements ◽  
Rigorous Error

AbstractEstimates of point-cloud positional accuracies in terrestrial laser scanning (TLS) datasets are currently limited to rudimentary combinations of GPS position error and manufacturer precision specifications. However, rigorous error propagation techniques can be applied to the three-dimensional TLS points and potentially integrated into software visualization and analysis products. Beyond the immediate value of qualitatively observing the distribution of expected TLS errors within a point cloud, rigorously estimated point errors can be further propagated to quantify expected errors in derived products such as point-to-point distance measurements, best-fit planes or volume computations. We review TLS error sources, detail their propagation through a rigid registration and illustrate the application of estimated TLS point errors to propagated snow volume uncertainties for a large and small TLS dataset. The resulting volume errors are of negligible size compared to the volume magnitudes, in no case exceeding 0.007% of the computed snow volume. For a dataset generating a large snow volume, the method of surface representation (e.g. grid or triangulated mesh) was more influential than the estimated TLS point errors on volume uncertainty. This suggests the random errors inherent in TLS measurement techniques are not a limiting factor in achievable snow volume accuracies.

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

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.

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

2018 ◽  
Vol 14 (11) ◽  
pp. 155014771881413 ◽  
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.

scholarly journals Evaluations on The Use Of 3d Terrestrial Laser Scanning Technology in Architectural Conservation Projects

2021 ◽  
Author(s):  
Saadet Armağan Güleç Korumaz ◽  
◽  
Büşra Kubiloğlu ◽  
Keyword(s):  
Cultural Heritage ◽  
Point Cloud ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Terrestrial Laser Scanning ◽  
Field Studies ◽  
High Accuracy ◽  
Two Dimensional ◽  
Conservation Projects ◽  
Architectural Documentation

3D Laser Scanning technologies have proven to be significant way to architectural documentation studies. Due to these facilities, the use of technology in architectural documentation have become widespread day by day. Thanks to these technologies it is possible to get high accuracy and intense data in a short time compared to conventional methods. Therefore, this technology has increased the content and quality of conservation practices. The technology is mainly aimed at obtaining a three-dimensional model or two-dimensional layouts from a dense and detailed point cloud. Terrestrial Laser Scanning (TLS) does not only support simple CAD-based conservation projects, but also allows obtaining high-resolution plane pictures, art tours, three-dimensional mesh models, and two-dimensional maps. Besides these possibilities, high accuracy data on the morphological properties of the documented object can be obtained as a result of the analyses including point cloud. On the other hand, the technology gives possibility data to be shared in different environments and filtered data can be used online. Thus, different disciplines are able to easily access information. These features of technology add a different dimension to the studies in the field of cultural heritage and contribute to the digitalization of the heritage. In the scope of this study, evaluations are made regarding the innovations and usage possibilities brought by TLS technology to architectural documentation field based on the cultural heritage samples. In addition, within the scope of the study, trials were made on field studies for parameters that will affect data quality, accuracy and speed. In addition, within the scope of the study, some tests were made on field studies for parameters affecting data quality, accuracy and speed. With the obtained results, evaluations have been made to increase the usage potential of the technology today.

The Advantages of Using Laser Scanners in Surveying in Protected Sites

2015 ◽  
pp. 382-402
Author(s):  
Gülhan Benli
Keyword(s):  
Protected Areas ◽  
Point Cloud ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Laser Scanners ◽  
Point Data

Since the 2000s, terrestrial laser scanning, as one of the methods used to document historical edifices in protected areas, has taken on greater importance because it mitigates the difficulties associated with working on large areas and saves time while also making it possible to better understand all the particularities of the area. Through this technology, comprehensive point data (point clouds) about the surface of an object can be generated in a highly accurate three-dimensional manner. Furthermore, with the proper software this three-dimensional point cloud data can be transformed into three-dimensional rendering/mapping/modeling and quantitative orthophotographs. In this chapter, the study will present the results of terrestrial laser scanning and surveying which was used to obtain three-dimensional point clouds through three-dimensional survey measurements and scans of silhouettes of streets in Fatih in Historic Peninsula in Istanbul, which were then transposed into survey images and drawings. The study will also cite examples of the facade mapping using terrestrial laser scanning data in Istanbul Historic Peninsula Project.

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

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.

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

Forests ◽  
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.

scholarly journals Modern Geodetic Measurement Techniques in Gravimetric Studies on the Example of Gypsum Karst in the Siesławice Region

2018 ◽  
Vol 35 ◽  
pp. 03002 ◽  
Author(s):  
Sławomir Porzucek ◽  
Monika Łój ◽  
Karolina Matwij ◽  
Wojciech Matwij
Keyword(s):  
Laser Scanning ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Field Studies ◽  
Surface Zone ◽  
Three Dimensional Model ◽  
Geodetic Measurement ◽  
Near Surface ◽  
Gypsum Karst

In the region of Siesławice (near Busko-Zdrój, Poland) there are unique phenomena of gypsum karst. Atmospheric factors caused numerous gypsum outcrops, canals and underground voids. The article presents the possibility of using non-invasive gravimetric surveys supplemented with geodetic measurements to illustrate karst changes occurring around the void. The use of modern geodetic measurement techniques including terrestrial and airborne laser scanning enables to generate a digital terrain model and a three-dimensional model of voids. Gravimetric field studies allowed to map the anomalies of the gravitational field of the near-surface zone. Geodetic measurement results have made it possible to accurately determine the terrain correction that supplemented the gravimetric anomaly information. Geophysical interpretation indicate the presence of weathered rocks in the near surface zone and fractures and loosened zones located surround the karst cave.

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