scholarly journals High resolution digital 3D modelling of subsurface morphological structures of Koutouki Cave, Greece

2020 ◽  
Vol 49 (2-3) ◽  
Author(s):  
Aliki Konsolaki ◽  
Emmanuel Vassilakis ◽  
Leonidas Gouliotis ◽  
Georgios Kontostavlos ◽  
Vassilis Giannopoulos
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Open Space ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Column Height ◽  
Indoor Environments ◽  
Terrain Analysis ◽  
Dimensional Measurements ◽  
Quantification Analysis

Remote sensing techniques and laser scanning technology have given us the opportunity to study indoor environments, such as caves, with their complex and unique morphology. In the presented case study, we used a handheld laser scanner for acquiring points with projected coordinate information (X, Y, Z) covering the entire show cave of Koutouki; including its hidden passages and dark corners. The point cloud covers the floor, the walls, and the roof of the cave, as well as the stalactites, stalagmites and the connected columns that constitute the decoration of the cave. The absolute and exact placement of the point cloud within a geographic reference frame gives us the opportunity for three-dimensional measurements and detailed visualization of the subsurface structures. Using open - source software, we managed to make a quantification analysis of the terrain and generated morphological and geometric features of the speleothems. We identified 55 columns by using digital terrain analysis and processed them statistically in order to correlate them to the frame of the cave development. The parameters that derived are the contours, each column height, the speleothem geometry and volume, as well as the volume of the open space cavity. We argue that by the demonstrated methodology, it is possible to identify with high accuracy and detail: the geomorphological features of a cave, an estimate of the speleogenesis, and the ability to monitor the evolution of a karstic system.Key words: cave, laser scanner, 3D representation, speleothems, SLAM.  

Replica Fabrication of a Greek Paleontological Find Utilising Laser Scanning and Fused Deposition Modeling

2014 ◽  
Vol 657 ◽  
pp. 795-799 ◽  
Author(s):  
Anastasios Chatzikonstantinou ◽  
Dimitrios Tzetzis ◽  
Panagiotis Kyratsis ◽  
Nikolaos Bilalis
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Fused Deposition Modeling ◽  
Complex Geometry ◽  
Low Cost ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Analytical Methodology ◽  
Fused Deposition ◽  
Deposition Modeling

The current work demonstrates a feasibility study on the generation of a copy, having a highly complex geometry, of a Greek paleontological find utilising reverse engineering and low-cost rapid prototyping techniques. A part of the jaw bone of a cave bear (Ursus spelaeus) that lived during the Pleistocene and became extinct about 10,000 years ago was digitized using a three-dimensional laser scanner. The resulting point-cloud of the scans was treated with a series of advanced software for the creation of surfaces and ultimately for a digital model. The generated model was three-dimensionally built by the aid of a Fused Deposition Modeling (FDM) apparatus. An analytical methodology is presented revealing the step by step approach from the scanning to the prototyping. It is believed that a variety of interested parties could benefit from such an analytical approach, including, production engineers, three-dimensional CAD users and designers, paleontologists and museum curators.

scholarly journals AUTOMATIC GENERATION OF INDOOR NAVIGABLE SPACE USING A POINT CLOUD AND ITS SCANNER TRAJECTORY

2017 ◽  
Vol IV-2/W4 ◽  
pp. 393-400 ◽  
Author(s):  
B. R. Staats ◽  
A. A. Diakité ◽  
R. L. Voûte ◽  
S. Zlatanova
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Region Growing ◽  
Automatic Generation ◽  
Indoor Environments ◽  
New Approaches ◽  
Floor Plans ◽  
Dynamic Objects ◽  
Voxel Space

Automatic generation of indoor navigable models is mostly based on 2D floor plans. However, in many cases the floor plans are out of date. Buildings are not always built according to their blue prints, interiors might change after a few years because of modified walls and doors, and furniture may be repositioned to the user’s preferences. Therefore, new approaches for the quick recording of indoor environments should be investigated. This paper concentrates on laser scanning with a Mobile Laser Scanner (MLS) device. The MLS device stores a point cloud and its trajectory. If the MLS device is operated by a human, the trajectory contains information which can be used to distinguish different surfaces. In this paper a method is presented for the identification of walkable surfaces based on the analysis of the point cloud and the trajectory of the MLS scanner. This method consists of several steps. First, the point cloud is voxelized. Second, the trajectory is analysing and projecting to acquire seed voxels. Third, these seed voxels are generated into floor regions by the use of a region growing process. By identifying dynamic objects, doors and furniture, these floor regions can be modified so that each region represents a specific navigable space inside a building as a free navigable voxel space. By combining the point cloud and its corresponding trajectory, the walkable space can be identified for any type of building even if the interior is scanned during business hours.

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.

Application of Constructing Three-Dimensional Model Using Laser Scanning Technology

2011 ◽  
Vol 94-96 ◽  
pp. 86-89
Author(s):  
Wen Long Liu ◽  
Xiao Ping Zhao ◽  
Bao Guo Xu
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Range Image ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Building Models ◽  
Three Dimensional Models ◽  
Segmentation Point

Starting from the principle of three-dimensional laser scanner and after analyzing the positioning error of point cloud, in this paper the following key problems confronted in data processing are researched ,the problems are range image segmentation, point cloud registration, point cloud filtering, absolute positioning and stitching data, modeling in AutoCAD or 3Dmax. Then, examples were introduced in constructing three-dimensional model using laser scanning technology. The results showed that the use of this technology can provide high-precision building models, which is important in constructing three-dimensional models and very helpful of digital cities.

scholarly journals Study on Real-Time Point Cloud Superimposition on Camera Image to Assist Environmental Three-Dimensional Laser Scanning

2021 ◽  
Vol 15 (3) ◽  
pp. 324-333
Author(s):  
Kenta Ohno ◽  
Hiroaki Date ◽  
Satoshi Kanai ◽  
◽  
Keyword(s):  
Real Time ◽  
Point Cloud ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Point Clouds ◽  
Laser Measurements ◽  
Attitude Error ◽  
Camera Image ◽  
Actual Environment

Recently, three-dimensional (3D) laser scanning technology using terrestrial laser scanner (TLS) has been widely used in the fields of plant manufacturing, civil engineering and construction, and surveying. It is desirable for the operator to be able to immediately and intuitively confirm the scanned point cloud to reduce unscanned regions and acquire scanned point clouds of high quality. Therefore, in this study, we developed a method to superimpose the point cloud on the actual environment to assist environmental 3D laser measurements, allowing the operator to check the scanned point cloud or unscanned regions in real time using the camera image. The method included extracting the correspondences of the camera image and the image generated by point clouds by considering unscanned regions, estimating the camera position and attitude in the point cloud by sampling correspondence points, and superimposing the scanned point cloud and unscanned regions on the camera image. When the proposed method was applied to two types of environments, that is, a boiler room and university office, the estimated camera image had a mean position error of approximately 150 mm and mean attitude error of approximately 1°, while the scanned point cloud and unscanned regions were superimposed on the camera image on a tablet PC at a rate of approximately 1 fps.

scholarly journals DATUM FEATURE EXTRACTION AND DEFORMATION ANALYSIS METHOD BASED ON NORMAL VECTOR OF POINT CLOUD

2018 ◽  
Vol XLII-3 ◽  
pp. 1601-1606
Author(s):  
W. Sun ◽  
J. Wang ◽  
F. Jin ◽  
Z. Liang ◽  
Y. Yang
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Normal Vector ◽  
Analysis Method ◽  
Data Set

In order to solve the problem lacking applicable analysis method in the application of three-dimensional laser scanning technology to the field of deformation monitoring, an efficient method extracting datum feature and analysing deformation based on normal vector of point cloud was proposed. Firstly, the kd-tree is used to establish the topological relation. Datum points are detected by tracking the normal vector of point cloud determined by the normal vector of local planar. Then, the cubic B-spline curve fitting is performed on the datum points. Finally, datum elevation and the inclination angle of the radial point are calculated according to the fitted curve and then the deformation information was analyzed. The proposed approach was verified on real large-scale tank data set captured with terrestrial laser scanner in a chemical plant. The results show that the method could obtain the entire information of the monitor object quickly and comprehensively, and reflect accurately the datum feature deformation.

Handheld Laser Scanner Research

2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Test Site ◽  
Optical Systems ◽  
Advantages And Disadvantages ◽  
Site Survey ◽  
Laser Scanners ◽  
Three Dimensional Models ◽  
The Stability

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

scholarly journals Comparison of Depth Camera and Terrestrial Laser Scanner in Monitoring Structural Deflections

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 201
Author(s):  
Michael Bekele Maru ◽  
Donghwan Lee ◽  
Kassahun Demissie Tola ◽  
Seunghee Park
Keyword(s):  
Optical Sensors ◽  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Point Clouds ◽  
Depth Camera ◽  
Terrestrial Laser Scanner ◽  
Cloud Data ◽  
3D Point Clouds ◽  
3D Information

Modeling a structure in the virtual world using three-dimensional (3D) information enhances our understanding, while also aiding in the visualization, of how a structure reacts to any disturbance. Generally, 3D point clouds are used for determining structural behavioral changes. Light detection and ranging (LiDAR) is one of the crucial ways by which a 3D point cloud dataset can be generated. Additionally, 3D cameras are commonly used to develop a point cloud containing many points on the external surface of an object around it. The main objective of this study was to compare the performance of optical sensors, namely a depth camera (DC) and terrestrial laser scanner (TLS) in estimating structural deflection. We also utilized bilateral filtering techniques, which are commonly used in image processing, on the point cloud data for enhancing their accuracy and increasing the application prospects of these sensors in structure health monitoring. The results from these sensors were validated by comparing them with the outputs from a linear variable differential transformer sensor, which was mounted on the beam during an indoor experiment. The results showed that the datasets obtained from both the sensors were acceptable for nominal deflections of 3 mm and above because the error range was less than ±10%. However, the result obtained from the TLS were better than those obtained from the DC.

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.

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