scholarly journals Accuracy Analysis of Measuring X-Y-Z Coordinates with Regard to the Investigation of the Tombolo Effect

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1167 ◽  
Author(s):  
Romuald Masnicki ◽  
Cezary Specht ◽  
Janusz Mindykowski ◽  
Paweł Dąbrowski ◽  
Mariusz Specht
Keyword(s):  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Accuracy Analysis ◽  
Measurement Results ◽  
Sea Currents ◽  
Measurement Of Coordinates ◽  
Narrow Belt ◽  
Sand And Gravel ◽  
Estimation Of Uncertainty

Tombolo is a narrow belt connecting the mainland with an island lying near the shore. It is formed as a result of sand and gravel being deposited by sea currents. In consequence, the seabed constantly rises and the shoreline moves towards the sea. This paper deals with accuracy analysis of the undertaken tombolo effect investigation, namely estimation of uncertainty of the measurement results. The aforementioned analysis concerns two methods used for creating a 3D beach model: Firstly, based on geodetic laser scanning (TLS—terrestrial laser scanning) and secondly, using images from unmanned aerial vehicles (UAV). The presented exemplary estimation of uncertainty of the measurement of coordinates X-Y-Z is based on the Polish case study.

scholarly journals Geospatial Modeling of the Tombolo Phenomenon in Sopot using Integrated Geodetic and Hydrographic Measurement Methods

2020 ◽  
Vol 12 (4) ◽  
pp. 737 ◽  
Author(s):  
Mariusz Specht ◽  
Cezary Specht ◽  
Janusz Mindykowski ◽  
Paweł Dąbrowski ◽  
Romuald Maśnicki ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Degradation Process ◽  
Natural Phenomena ◽  
Geospatial Modeling ◽  
Aerial Vehicle ◽  
Spatial Shape ◽  
Sea Currents ◽  
The Baltic ◽  
Narrow Belt ◽  
Sand And Gravel

A tombolo is a narrow belt connecting a mainland with an island lying near to the shore, formed as a result of sand and gravel being deposited by sea currents, most often created as a result of natural phenomena. However, it can also be caused by human activity, as is the case with the Sopot pier—a town located on the southern coast of the Baltic Sea in northern Poland (φ = 54°26’N, λ = 018°33’E). As a result, the seafloor rises constantly and the shoreline moves towards the sea. Moreover, there is the additional disturbing phenomenon consisting of the rising seafloor sand covering over the waterbody’s vegetation and threatening the city's spa character. Removal of the sand to another place has already been undertaken several times. There is a lack of precise geospatial data about the tombolo’s seafloor course, its size and spatial shape caused by only lowering the seafloor in random places, and the ongoing environmental degradation process. This article presents the results of extensive and integrated geodetic and hydrographic measurements, the purpose of which was to make a 3D model of the phenomena developing in Sopot. The measurements will help determine the size and speed of the geospatial changes. Most of the modern geodetic and hydrographic methods were used in the study of these phenomena. For the construction of the land part of geospatial model, the following were used: photos from the photogrammetric flight pass (unmanned aerial vehicle—UAV), laser scanning of the beach and piers, and satellite orthophotomaps for analysis of the coastline changes. In the sea part, bathymetric measurements were carried out with an unmanned surface vehicle (USV).

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

scholarly journals Evaluation of Terrestrial Laser Scanner Accuracy in the Control of Hydrotechnical Structures

2017 ◽  
Vol 39 (4) ◽  
pp. 45-57 ◽  
Author(s):  
Zbigniew Muszyński ◽  
Jarosław Rybak
Keyword(s):  
Laser Scanning ◽  
Reference Beam ◽  
Terrestrial Laser Scanning ◽  
Systematic Errors ◽  
Ground Movement ◽  
Engineering Practice ◽  
Reference Structure ◽  
Advantages And Disadvantages ◽  
Measurement Results ◽  
Horizontal Displacements

Abstract In many cases of monitoring or load testing of hydrotechnical structures, the measurement results obtained from dial gauges may be affected by random or systematic errors resulting from the instability of the reference beam. For example, the measurement of wall displacement or pile settlement may be increased (or decreased) by displacements of the reference beam due to ground movement. The application of surveying methods such as high-precision levelling, motorized tacheometry or even terrestrial laser scanning makes it possible to provide an independent reference measurement free from systematic errors. It is very important in the case of walls and piles embedded in the rivers, where the construction of reference structure is even more difficult than usually. Construction of an independent reference system is also complicated when horizontal testing of sheet piles or diaphragm walls are considered. In this case, any underestimation of the horizontal displacement of an anchored or strutted construction leads to an understated value of the strut’s load. These measurements are even more important during modernization works and repairs of the hydrotechnical structures. The purpose of this paper is to discuss the possibilities of using modern measurement methods for monitoring of horizontal displacements of an excavation wall. The methods under scrutiny (motorized tacheometry and terrestrial laser scanning) have been compared to classical techniques and described in the context of their practical use on the example hydrotechnical structure. This structure was a temporary cofferdam made from sheet pile wall. The research continuously conducted at Wroclaw University of Science and Technology made it possible to collect and summarize measurement results and practical experience. This paper identifies advantages and disadvantages of both analysed methods and presents a comparison of obtained measurement results of horizontal displacements. In conclusion, some recommendations have been formulated, which are relevant from the point of view of engineering practice.

scholarly journals Towards Tree Green Crown Volume: A Methodological Approach Using Terrestrial Laser Scanning

2020 ◽  
Vol 12 (11) ◽  
pp. 1841 ◽  
Author(s):  
Zihui Zhu ◽  
Christoph Kleinn ◽  
Nils Nölke
Keyword(s):  
Laser Scanning ◽  
Methodological Approach ◽  
Terrestrial Laser Scanning ◽  
Urban Trees ◽  
Volume Index ◽  
Convex Hulls ◽  
Tree Crown ◽  
Crown Volume ◽  
Matter Production

Crown volume is a tree attribute relevant in a number of contexts, including photosynthesis and matter production, storm resistance, shadowing of lower layers, habitat for various taxa. While commonly the total crown volume is being determined, for example by wrapping a convex hull around the crown, we present here a methodological approach towards assessing the tree green crown volume (TGCVol), the crown volume with a high density of foliage, which we derive by terrestrial laser scanning in a case study of solitary urban trees. Using the RGB information, we removed the hits on stem and branches within the tree crown and used the remaining leaf hits to determine TGCVol from k-means clustering and convex hulls for the resulting green 3D clusters. We derived a tree green crown volume index (TGCVI) relating the green crown volume to the total crown volume. This TGCVI is a measure of how much a crown is “filled with green” and scale-dependent (a function of specifications of the k-means clustering). Our study is a step towards a standardized assessment of tree green crown volume. We do also address a number of remaining methodological challenges.

scholarly journals COMBINED 3D BUILDING SURVEYING TECHNIQUES – TERRESTRIAL LASER SCANNING (TLS) AND TOTAL STATION SURVEYING FOR BIM DATA MANAGEMENT PURPOSES

2013 ◽  
Vol 19 (Supplement_1) ◽  
pp. S23-S32 ◽  
Author(s):  
Tarvo Mill ◽  
Aivars Alt ◽  
Roode Liias
Keyword(s):  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Geodetic Survey ◽  
Economic Benefits ◽  
Accurate Information ◽  
Total Station ◽  
Existing Building ◽  
Building Information ◽  
Design And Construction

Building information modelling (BIM) represents the process of development and use of a computer generated model to simulate the planning, design, construction and operation of a building. The utilisation of building information models has increased in recent years due to their economic benefits in design and construction phases and in building management. BIM has been widely applied in the design and construction of new buildings but rarely in the management of existing ones. The point of creating a BIM model for an existing building is to produce accurate information related to the building, including its physical and functional characteristics, geometry and inner spatial relationships. The case study provides a critical appraisal of the process of both collecting accurate survey data using a terrestrial laser scanner combined with a total station and creating a BIM model as the basis of a digital management model. The case study shows that it is possible to detect and define facade damage by integration of the laser scanning point cloud and the creation of the BIM model. The paper will also give an overview of terrestrial laser scanning (TLS), total station surveying, geodetic survey networks and data processing to create a BIM model.

Sign in / Sign up

Export Citation Format

Share Document