scholarly journals DYNAMIC OBJECTS GEOMETRY MEASUREMENT BY LASER SCANNING – A CASE STUDY

2021 ◽  
Vol 1 ◽  
pp. 41-56
Author(s):  
Andrzej Kwinta ◽  
◽  
Robert Gradka ◽  
Keyword(s):  
Laser Scanning ◽  
Moving Objects ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Moving Object ◽  
Odra River ◽  
The Subject ◽  
Geometry Measurement ◽  
And Control

The objective of the study was to analyse of measurement of moving objects by means of the Total Station (TS) method and Terrestrial Laser Scanning (TLS). The subject of the tests was the “Polinka” gondola cable car over the Odra river in Wrocław. Research covered the basic and control measurements. The results of observations of suspension ropes’ deflection of the cable car in kinematical state were compared for various degrees of loading. During the motion of the gondola, the shape of the pull and supporting rope is subject to constant shifts. TS measurements are restricted solely to registering interim positioning of the points of pull lines (measurement of static objects). Laser scanner measurements may reveal changes in the location of many points (i.e. drive lines, catenaries or carriages) within a unit of time. The tests were designed to show whether it is possible to capture the shifts in geometry of the moving object (mainly by means of the TLS methods - in the course of constant vibrating of lines and during the movement of gondolas). The analyses indicated that it is possible to capture the changes of geometry by means of the TLS method, however, upon strictly specified measurement conditions.

scholarly journals 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

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.

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 Terrestrial Laser Scanning (TLS) as a detection method of the natural river valley microtopography – case study of the Upper Biebrza

2014 ◽  
Vol 46 (4) ◽  
pp. 276-278 ◽  
Author(s):  
Marcin Brach ◽  
Jarosław Chormański
Keyword(s):  
Laser Scanning ◽  
Detection Method ◽  
Laser Scanner ◽  
Digital Terrain Model ◽  
Terrestrial Laser Scanning ◽  
River Valley ◽  
Gis Analysis ◽  
Terrain Model ◽  
Digital Terrain

Abstract Terrestrial Laser Scanning (TLS) as a detection method of the natural river valley microtopography - case study of the Upper Biebrza. This paper concerns the use of Terrestrial Laser Scanning (TLS) methods and the Geographic Information Systems (GIS) analysis to determine microtopography of a natural river valley, case study of the upper Biebrza valley. The scientific problem analyzed in this paper is a morphology of the selected segments of the valley covered by sedge ecosystems which in natural stage form a characteristic tussocks from their root systems. In order to capture the microtopography it was necessary to remove vegetation from the selected areas, and then, for a five typical location, registration of its structure using the laser scanner. As a result the point cloud was generated for each of the selected area and after GIS analysis the microtopography was obtained in form of digital terrain model (DTM). The DTM of each area represents valleys microstructure possible to obtain by use of TLS (TLS DTM), is usually not registered by the Airborne Laser Scanning (ALS), and is the main reason of inaccuracy of the DTM obtained based on ALS. The resulting TLS DTM has been processed by various filtering methods to lower the noise and fill the voids from blocking the laser beam by a tussocks. Finally, this allowed to determine the spatial structure of each measurement field.

scholarly journals THE EXAMPLE OF USING INTENSITY ORTHOIMAGES IN TLS DATA REGISTRATION – A CASE STUDY

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 467-474 ◽  
Author(s):  
J. S. Markiewicz
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Point Distribution ◽  
Data Registration ◽  
Depth Maps ◽  
Source Data ◽  
Panoramic Images

The paper presents the orientation analysis of terrestrial laser scanning (TLS) data. In the proposed data processing methodology, point clouds are considered as panoramic images and orthoimages enriched by depth maps. Computer vision (CV) algorithms were used for the orientation; they were applied to test the correctness of the detection of tie points, as well as the accuracy, number and point distribution. For the source data, point clouds acquired from the terrestrial laser scanner Z+F 50063h for the two chambers in the Museum of King John III’s Palace in Wilanów were utilized.

scholarly journals Detection of Asphalt Pavement Cracks using mobile 2D laser scanning system: A case study of UTM 30LX laser scanner

2021 ◽  
Vol 1793 (1) ◽  
pp. 012038
Author(s):  
Viet Quoc Tran ◽  
Phuong Anh Thi To ◽  
Thi Ngoc Huynh ◽  
Anh Thu Thi Phan
Keyword(s):  
Laser Scanning ◽  
Asphalt Pavement ◽  
Laser Scanner ◽  
Scanning System ◽  
System A ◽  
Laser Scanning System

scholarly journals Can Leaf Water Content Be Estimated Using Multispectral Terrestrial Laser Scanning? A Case Study With Norway Spruce Seedlings

2018 ◽  
Vol 9 ◽  
Author(s):  
Samuli Junttila ◽  
Junko Sugano ◽  
Mikko Vastaranta ◽  
Riikka Linnakoski ◽  
Harri Kaartinen ◽  
...  
Keyword(s):  
Water Content ◽  
Norway Spruce ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Leaf Water ◽  
Leaf Water Content

Inspiratory Speech as a Management Option for Spastic Dysphonia

1992 ◽  
Vol 101 (5) ◽  
pp. 375-382 ◽  
Author(s):  
Gordon A. Harrison ◽  
Richard H. Troughear ◽  
Pamela J. Davis ◽  
Alison L. Winkworth
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Voice Quality ◽  
Management Option ◽  
Communication Problems ◽  
Partial Pressures ◽  
The Subject ◽  
And Control ◽  
Laryngeal Resistance

A case study is reported of a subject who has used inspiratory speech (IS) for 6 years as a means of overcoming the communication problems of long-standing adductor spastic dysphonia (ASD). The subject was studied to confirm his use of IS, determine the mechanisms of its production, investigate its effects on ventilatory gas exchange, and confirm that it was perceptually preferable to ASD expiratory speech (ES). Results showed that the production and control of a high laryngeal resistance to airflow were necessary for usable IS. Voice quality was quantitatively and perceptually poor; however, the improved fluency and absence of phonatory spasm made IS the preferred speaking mode for both the listener and the speaker. Transcutaneous measurements of the partial pressures of oxygen and carbon dioxide in the subject's blood were made during extended speaking periods. These measurements indicated that ventilation was unchanged during IS, and that ventilation during ES was similar to the “hyperventilation” state of normal speakers. The reasons for the absence of phonatory spasm during IS are discussed, and the possibility of its use as a noninvasive management option for other ASD sufferers is addressed.

Influence of Ball and Background Patterns on Perception of Visual Direction of a Moving Object

1979 ◽  
Vol 49 (2) ◽  
pp. 343-346 ◽  
Author(s):  
Marcella V. Ridenour
Keyword(s):  
Analysis Of Variance ◽  
Moving Objects ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Moving Object ◽  
Visual Direction ◽  
Visual Patterns ◽  
Prediction Time ◽  
The Subject ◽  
Three Dimensional Space

30 boys and 30 girls, 6 yr. old, participated in a study assessing the influence of the visual patterns of moving objects and their respective backgrounds on the prediction of objects' directionality. An apparatus was designed to permit modified spherical objects with interchangeable covers and backgrounds to move in three-dimensional space in three directions at selected speeds. The subject's task was to predict one of three possible directions of an object: the object either moved toward the subject's midline or toward a point 18 in. to the left or right of the midline. The movements of all objects started at the same place which was 19.5 ft. in front of the subject. Prediction time was recorded on 15 trials. Analysis of variance indicated that visual patterns of the moving object did not influence the prediction of the object's directionality. Visual patterns of the background behind the moving object did not influence the prediction of the object's directionality except during the conditions of a light nonpatterned moving object. It was concluded that visual patterns of the background and that of the moving object have a very limited influence on the prediction of direction.

scholarly journals 3D MODELS OF OBJECTS IN PROCESS OF RECONSTRUCTION

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Jovana Radović
Keyword(s):  
Laser Scanning ◽  
Laser System ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
3D Models ◽  
Terrestrial Laser Scanner ◽  
Accurate Data ◽  
Final Model ◽  
Airborne Laser

Within the last years terrestrial and airborne laser scanning has become a powerful technique for fast and efficient three-dimensional data acquisition of different kinds of objects. Airborne laser system (LiDAR) collects accurate georeferenced data of extremely large areas very quickly while the terrestrial laser scanner produces dense and geometrically accurate data. The combination of these two segments of laser scanning provides different areas of application. One of the applications is in the process of reconstruction of objects. Objects recorded with laser scanning technology and transferred into the final model represent the basis for building an object as it was original. In this paper, there will be shown two case studies based on usage of airborne and terrestrial laser scanning and processing of the data collected by them.

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