scholarly journals Assessment of Tree Diameter Estimation Methods from Mobile Laser Scanning in a Historic Garden

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1013
Author(s):  
Enrique Pérez-Martín ◽  
Serafín López-Cuervo Medina ◽  
Tomás Herrero-Tejedor ◽  
Miguel Angel Pérez-Souza ◽  
Julian Aguirre de Mata ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Laser Scanning ◽  
Mean Squared Error ◽  
Reference Sample ◽  
3D Models ◽  
World Heritage Site ◽  
Estimation Methods ◽  
Forest Inventories ◽  
3D Data ◽  
Unesco World Heritage Site

Geo-referenced 3D models are currently in demand as an initial knowledge base for cultural heritage projects and forest inventories. The mobile laser scanning (MLS) used for geo-referenced 3D models offers ever greater efficiency in the acquisition of 3D data and their subsequent application in the fields of forestry. In this study, we have analysed the performance of an MLS with simultaneous localisation and mapping technology (SLAM) for compiling a tree inventory in a historic garden, and we assessed the accuracy of the estimates of diameter at breast height (DBH, a height of 1.30 m) calculated from three fitting algorithms: RANSAC, Monte Carlo, and Optimal Circle. The reference sample used was 378 trees from the Island Garden, a historic garden and UNESCO World Heritage site in Aranjuez, Spain. The time taken to acquire the data by MLS was 27 min 37 s, in an area of 2.38 ha. The best results were obtained with the Monte Carlo fitting algorithm, which was able to estimate the DBH of 77% of the 378 trees in the study, with a root mean squared error (RMSE) of 5.31 cm and a bias of 1.23 cm. The proposed methodology enabled a supervised detection of the trees and automatically estimated the DBH of most trees in the study, making this a useful tool for the management and conservation of a historic garden.

3D City Modeling and Visualization for Smart Phone Applications

2012 ◽  
pp. 254-296
Author(s):  
Juha Hyyppä ◽  
Lingli Zhu ◽  
Zhengjun Liu ◽  
Harri Kaartinen ◽  
Anttoni Jaakkola
Keyword(s):  
Data Acquisition ◽  
Laser Scanning ◽  
3D Models ◽  
Image Capture ◽  
3D City Models ◽  
Central Computer ◽  
3D Data ◽  
Open Operation ◽  
City Modeling ◽  
City Models

Smartphones with larger screens, powerful processors, abundant memory, and an open operation system provide many possibilities for 3D city or photorealistic model applications. 3D city or photorealistic models can be used by the users to locate themselves in the 3D world, or they can be used as methods for visualizing the surrounding environment once a smartphone has already located the phone by other means, e.g. by using GNSS, and then to provide an interface in the form of a 3D model for the location-based services. In principle, 3D models can be also used for positioning purposes. For example, matching of images exported from the smartphone and then registering them in the existing 3D photorealistic world provides the position of the image capture. In that process, the central computer can do a similar image matching task when the users locate themselves interactively into the 3D world. As the benefits of 3D city models are obvious, this chapter demonstrates the technology used to provide photorealistic 3D city models and focus on 3D data acquisition and the methods available in 3D city modeling, and the development of 3D display technology for smartphone applications. Currently, global geoinformatic data providers, such as Google, Nokia (NAVTEQ), and TomTom (Tele Atlas), are expanding their products from 2D to 3D. This chapter is a presentation of a case study of 3D data acquisition, modeling and mapping, and visualization for a smartphone, including an example based on data collected by mobile laser scanning data from the Tapiola (Espoo, Finland) test field.

scholarly journals Impact of Calibrating Filtering Algorithms on the Quality of LiDAR-Derived DTM and on Forest Attribute Estimation through Area-Based Approach

2020 ◽  
Vol 12 (6) ◽  
pp. 918 ◽  
Author(s):  
Diogo N. Cosenza ◽  
Luísa Gomes Pereira ◽  
Juan Guerra-Hernández ◽  
Adrián Pascual ◽  
Paula Soares ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Mean Squared Error ◽  
Volume Estimation ◽  
Estimation Accuracy ◽  
Filtering Algorithms ◽  
Growing Stock ◽  
Forest Inventories ◽  
Dominant Height ◽  
Ground Point

Ground point filtering of the airborne laser scanning (ALS) returns is crucial to derive digital terrain models (DTMs) and to perform ALS-based forest inventories. However, the filtering calibration requires considerable knowledge from users, who normally perform it by trial and error without knowing the impacts of the calibration on the produced DTM and the forest attribute estimation. Therefore, this work aims at calibrating four popular filtering algorithms and assessing their impact on the quality of the DTM and the estimation of forest attributes through the area-based approach. The analyzed filters were the progressive triangulated irregular network (PTIN), weighted linear least-squares interpolation (WLS) multiscale curvature classification (MCC), and the progressive morphological filter (PMF). The calibration was established by the vertical DTM accuracy, the root mean squared error (RMSE) using 3240 high-accuracy ground control points. The calibrated parameter sets were compared to the default ones regarding the quality of the estimation of the plot growing stock volume and the dominant height through multiple linear regression. The calibrated parameters allowed for producing DTM with RMSE varying from 0.25 to 0.26 m, against a variation from 0.26 to 0.30 m for the default parameters. The PTIN was the least affected by the calibration, while the WLS was the most affected. Compared to the default parameter sets, the calibrated sets resulted in dominant height equations with comparable accuracies for the PTIN, while WLS, MCC, and PFM reduced the models’ RMSE by 6.5% to 10.6%. The calibration of PTIN and MCC did not affect the volume estimation accuracy, whereas calibrated WLS and PMF reduced the RMSE by 3.4% to 7.9%. The filter calibration improved the DTM quality for all filters and, excepting PTIN, the filters increased the quality of forest attribute estimation, especially in the case of dominant height.

scholarly journals EVOLVING TECHNIQUES OF DOCUMENTATION OF A WORLD HERITAGE SITE IN LAHORE

2017 ◽  
Vol XLII-2/W5 ◽  
pp. 33-40 ◽  
Author(s):  
R. Arif ◽  
K. Essa
Keyword(s):  
Laser Scanning ◽  
World Heritage ◽  
World Heritage Site ◽  
Heritage Conservation ◽  
Full Potential ◽  
Architectural Drawings ◽  
World Heritage Sites ◽  
Heritage Sites ◽  
Heritage Site ◽  
Unesco World Heritage Site

Lahore is an ancient, culturally rich city amidst which are embedded two world heritage sites. The state of historic preservation in the country is impoverished with a dearth of training and poor documentation skills, thus these monuments are decaying and in dire need of attention. The Aga Khan Cultural Service - Pakistan is one of the first working in heritage conservation in the country. AKCSP is currently subjecting the UNESCO World Heritage site of the Mughal era Lahore Fort to an intensive and multi-faceted architectural documentation process. This is presented here as a case study to chart the evolution of documentation techniques and enunciate the spectrum of challenges faced in the documentation of an intricate Mughal heritage site for conservation in the Pakistani context.<br><br> 3D - laser scanning is used for the purpose of heritage conservation for the first time, and since has been utilised on heritage buildings and urban fabric in ongoing projects. These include Lahore Fort, Walled city of Lahore as well as the Baltit Fort, a project restored in the past, assisting in the maintenance of conserved buildings. The documentation team is currently discovering the full potential of this technology especially its use in heritage conservation simultaneously overcoming challenges faced. Moreover negotiating solutions to auto-generate 2D architectural drawings from the 3D pointcloud output. The historic architecture is juxtaposed with contemporary technology in a region where such a combination is rarely found. The goal is to continually develop the documentation methodologies whilst investigating other technologies in the future.

scholarly journals Applicability Assessments of Close-Range Photogrammetry for Slope Face 3D Modelling

2020 ◽  
Vol 8 (3) ◽  
pp. 143-150
Author(s):  
Haqul Baramsyah ◽  
Less Rich
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Laser Scanner ◽  
Cost Effective ◽  
3D Models ◽  
Digital Photogrammetry ◽  
Aerial Photogrammetry ◽  
3D Data ◽  
Image Capturing ◽  
Close Range

The digital single lens reflex (DSLR) cameras have been widely accepted to use in slope face photogrammetry rather than the expensive metric camera used for aerial photogrammetry. 3D models generated from digital photogrammetry can approach those generated from terrestrial laser scanning in term of scale and level of detail. It is cost effective and has equipment portability. This paper presents and discusses the applicability of close-range digital photogrammetry to produce 3D models of rock slope faces. Five experiments of image capturing method were conducted to capture the photographs as the input data for processing. As a consideration, the appropriate baseline lengths to capture the slope face to get better result are around 1/6 to 1/8 of target distance.  A fine quality of 3D model from data processing is obtained using strip method and convergent method with 80% overlapping in each photograph. A random camera positions with different distances from the slope face can also generate a good 3D model, however the entire target should be captured in each photograph. The accuracy of the models is generated by comparing the 3D models produced from photogrammetry with the 3D data obtained from laser scanner. The accuracy of 3D models is quite satisfactory with the mean error range from 0.008 to 0.018 m.

scholarly journals A MULTI-PURPOSE CULTURAL HERITAGE DATA PLATFORM FOR 4D VISUALIZATION AND INTERACTIVE INFORMATION SERVICES

2020 ◽  
Vol XLIII-B4-2020 ◽  
pp. 583-590 ◽  
Author(s):  
C. Ioannidis ◽  
S. Verykokou ◽  
S. Soile ◽  
A.-M. Boutsi
Keyword(s):  
Cultural Heritage ◽  
3D Models ◽  
World Heritage Site ◽  
Critical Knowledge ◽  
Heritage Site ◽  
Unesco World Heritage Site ◽  
Arduous Task ◽  
Case Study Site ◽  
Historical Resources ◽  
3D Capture

Abstract. The already arduous task of collecting, processing and managing heterogeneous cultural heritage data is getting more intense in terms of indexing, interaction and dissemination. This paper presents the creation of a 4D web-based platform as a centralized data hub, moving beyond advanced photogrammetric techniques for 3D capture and multi-dimensional documentation. Precise metric data, generated by a combination of image-based, range and surveying techniques, are spatially, logically and temporally correlated with cultural and historical resources, in order to form a critical knowledge base for multiple purposes and user types. Unlike conventional information systems, the presented platform, which adopts a relational database model, has the following front-end functionalities: (i) visualization of high-resolution 3D models based on distance dependent Level of Detail (LoD) techniques; (ii) web Augmented Reality; and (iii) interactive access and retrieval services. Information deduced from the developed services is tailored to different target audiences: scientific community, private sector, public sector and general public. The case study site is the UNESCO world heritage site of Meteora, Greece, and particularly, two inaccessible huge rocks, the rock of St. Modestos, known as Modi, and the Alyssos rock.

scholarly journals Comparison of Some of Estimation methods of Stress-Strength Model: R = P(Y < X < Z)

2021 ◽  
Vol 18 (2(Suppl.)) ◽  
pp. 1103
Author(s):  
Sairan Hamza Raheem ◽  
Bayda Atiya Kalaf ◽  
Abbas Najim Salman
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Moment Method ◽  
Mean Squared Error ◽  
Rayleigh Distribution ◽  
Minimum Variance ◽  
Estimation Methods ◽  
Strength Model ◽  
Minimum Variance Unbiased Estimator ◽  
Squared Error

In this study, the stress-strength model R = P(Y < X < Z)  is discussed as an important parts of reliability system by assuming that the random variables follow Invers Rayleigh Distribution. Some traditional estimation methods are used    to estimate the parameters  namely; Maximum Likelihood, Moment method, and Uniformly Minimum Variance Unbiased estimator and Shrinkage estimator using three types of shrinkage weight factors. As well as, Monte Carlo simulation are used to compare the estimation methods based on mean squared error criteria.  

3D-GIS for support of works on geotechnical monitoring of objects of main pipelines

2020 ◽  
Vol 10 (4) ◽  
pp. 342-351
Author(s):  
Elizaveta M. Makarycheva ◽  
◽  
Тaras I. Kuznetsov ◽  
Sergey A. Polovkov ◽  
Alexander I. Baryshev ◽  
...  
Keyword(s):  
Laser Scanning ◽  
3D Models ◽  
3D Gis ◽  
Distributed Information ◽  
Geotechnical Monitoring ◽  
3D Data ◽  
Main Pipelines ◽  
Research Problems ◽  
Automated Processing ◽  
Geographically Distributed

The article presents the results of the development of specialized 3D-GIS as a tool for structuring, storing, reproducing, processing and analyzing data for geotechnical monitoring of main pipeline facilities. The authors proposed a solution to the problem of the complexity of processing large amounts of data by creating a unified environment of geographically distributed information through a geo-portal and implementing services on the basis of the geo-portal for automated processing and analysis of information, as well as computational algorithms. The description of the structure and functionality of the developed 3D-GIS is given. Methods for obtaining and processing 3D data are disclosed, and the data is analyzed. Results of a quantitative assessment of changes in the natural environment, plan-elevation position and geometry of objects based on the data of several cycles of surveys by methods of ground and air laser scanning are presented. The advantages of 3D-GIS in solving problems of geotechnical monitoring, as well as the possibility of using 3D-models for solving other production and research problems are highlighted.

scholarly journals Sri Dalada Maligawa – 3D-Scanning and Documentation of the Temple of the Sacred Tooth Relic at Kandy, Sri Lanka

2017 ◽  
Vol IV-2/W2 ◽  
pp. 229-236 ◽  
Author(s):  
M. Rahrig ◽  
A. Luib
Keyword(s):  
Laser Scanning ◽  
Main Part ◽  
World Heritage Site ◽  
Transfer Of Knowledge ◽  
Heritage Site ◽  
Unesco World Heritage Site ◽  
Site Monitoring ◽  
Scan Data ◽  
The Buddha ◽  
The Temple

Sri Dalada Maligawa – the Temple of the Sacred Tooth Relic – is one of the most important pilgrim sites in Buddhist culture. It is the main part of the UNESCO World Heritage Site <i>Sacred City of Kandy</i>. Since the end of the 17<sup>th</sup> century the temple has been keeping the sacred tooth of the Buddha. Until now an accurate documentation of the temple with all its rich decorations is missing. The Temple is built in an area vulnerable to environmental factors like earthquakes or monsoon rains and was the target of terrorist attacks. To help preserving this important cultural heritage a research project was carried out. Main part of the project was a 3D-documentation of the entire temple by using Terrestrial-Laser-Scanning (TLS) and the creating of CAD-Plans. In addition to the documentation of the architecture several details were taken in high resolution by Structured-Light-Scanning (SLS). All data will be part of the digital archive of the temple and were used as a base for a general site monitoring, especially to observe cracks. Next to the mere documentation a transfer of knowledge was another aim of the project. In future most of the analysis of the scan data can be done by local specialists.

scholarly journals Terrestrial laser scanning for heritage conservation: the Cologne Cathedral documentation project

2017 ◽  
Vol IV-2/W2 ◽  
pp. 213-220 ◽  
Author(s):  
D. Pritchard ◽  
J. Sperner ◽  
S. Hoepner ◽  
R. Tenschert
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
World Heritage Site ◽  
Industrial Sites ◽  
Architectural Engineering ◽  
Heritage Site ◽  
Unesco World Heritage Site ◽  
Invaluable Tool ◽  
Heritage Buildings ◽  
Cologne Cathedral

Contemporary terrestrial laser scanners and photogrammetric imaging systems are an invaluable tool in providing objectively precise, as-built records of existing architectural, engineering and industrial sites. The comprehensive three-dimensional (3D) recording of culturally important sites such as heritage buildings, monuments, and sites can serve a variety of invaluable purposes; the data can assist in the conservation, management, and repair of a structure, as well as provide a visually engaging educational resource for both the public and scholars. The acquired data acts as a form of digital preservation, a timeless virtual representation of the as-built structure. The technical capability of these systems is particularly suited for the documentation of a richly articulated and detailed building such as the high Gothic Cologne Cathedral.<br><br> The 3D documentation of the Cologne Cathedral UNESCO World Heritage Site is a multiphase project developed by Heriot-Watt University, Edinburgh in partnership with the Fresenius University of Applied Sciences, Cologne, and the Metropolitankapitel der Hohen Domkirche Köln Dombauhütte. The project has also received generous support from Zoller + Fröhlich (Z+F) and the City of Cologne.

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