scholarly journals A non-destructive technique for health assessment of fire-damaged concrete elements using terrestrial laser scanning

2016 ◽  
Vol 6 (4) ◽  
pp. 665-679 ◽  
Author(s):  
Wallace Mukupa ◽  
Gethin W. Roberts ◽  
Craig M. Hancock ◽  
Khalil Al-Manasir
Forests ◽  
2016 ◽  
Vol 7 (12) ◽  
pp. 87 ◽  
Author(s):  
Yuan Sun ◽  
Xinlian Liang ◽  
Ziyu Liang ◽  
Clive Welham ◽  
Weizheng Li

2018 ◽  
Vol 427 ◽  
pp. 217-229 ◽  
Author(s):  
Atticus E.L. Stovall ◽  
Kristina J. Anderson-Teixeira ◽  
Herman H. Shugart

Drones ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 32 ◽  
Author(s):  
Angus D. Warfield ◽  
Javier X. Leon

Mangroves provide a variety of ecosystem services, which can be related to their structuralcomplexity and ability to store carbon in the above ground biomass (AGB). Quantifying AGB inmangroves has traditionally been conducted using destructive, time-consuming, and costlymethods, however, Structure-from-Motion Multi-View Stereo (SfM-MVS) combined withunmanned aerial vehicle (UAV) imagery may provide an alternative. Here, we compared the abilityof SfM-MVS with terrestrial laser scanning (TLS) to capture forest structure and volume in threemangrove sites of differing stand age and species composition. We describe forest structure in termsof point density, while forest volume is estimated as a proxy for AGB using the surface differencingmethod. In general, SfM-MVS poorly captured mangrove forest structure, but was efficient incapturing the canopy height for volume estimations. The differences in volume estimations betweenTLS and SfM-MVS were higher in the juvenile age site (42.95%) than the mixed (28.23%) or mature(12.72%) age sites, with a higher stem density affecting point capture in both methods. These resultscan be used to inform non-destructive, cost-effective, and timely assessments of forest structure orAGB in mangroves in the future.


2020 ◽  
Vol 456 ◽  
pp. 117751 ◽  
Author(s):  
Sruthi M. Krishna Moorthy ◽  
Pasi Raumonen ◽  
Jan Van den Bulcke ◽  
Kim Calders ◽  
Hans Verbeeck

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 660 ◽  
Author(s):  
Yangbo Deng ◽  
Kunyong Yu ◽  
Xiong Yao ◽  
Qiaoya Xie ◽  
Yita Hsieh ◽  
...  

The accurate estimation of leaf area is of great importance for the acquisition of information on the forest canopy structure. Currently, direct harvesting is used to obtain leaf area; however, it is difficult to quickly and effectively extract the leaf area of a forest. Although remote sensing technology can obtain leaf area by using a wide range of leaf area estimates, such technology cannot accurately estimate leaf area at small spatial scales. The purpose of this study is to examine the use of terrestrial laser scanning data to achieve a fast, accurate, and non-destructive estimation of individual tree leaf area. We use terrestrial laser scanning data to obtain 3D point cloud data for individual tree canopies of Pinus massoniana. Using voxel conversion, we develop a model for the number of voxels and canopy leaf area and then apply it to the 3D data. The results show significant positive correlations between reference leaf area and mass (R2 = 0.8603; p < 0.01). Our findings demonstrate that using terrestrial laser point cloud data with a layer thickness of 0.1 m and voxel size of 0.05 m can effectively improve leaf area estimations. We verify the suitability of the voxel-based method for estimating the leaf area of P. massoniana and confirmed the effectiveness of this non-destructive method.


2021 ◽  
Author(s):  
Markku Åkerblom ◽  
Pekka Kaitaniemi

Abstract Background Laser scanning technology has opened new horizons for the research of forest dynamics, because it provides a largely automated and non-destructive method to rapidly capture the structure of individual trees and entire forest stands at multiple spatial scales. The structural data themselves or in combination with additional remotely sensed data also provide information on the local physiological state of structures within trees. The capacity of new methods is facilitated by the ongoing development of automated processing tools that are designed to capture information from the point cloud data provided by the remote measurements. Scope Terrestrial laser scanning (TLS), performed from the ground or from unmanned aerial vehicles, in particular, has potential to become a unifying measurement standard for forest research questions, because the equipment is flexible to use in the field and has the capacity to capture branch-level structural information at the forestplot or even forest scale. This issue of Annals of Botany includes selected papers that exemplify the current and potential uses of TLS, such as for examination of crown interactions between trees, growth dynamics of mixed stands, non-destructive characterization of urban trees, and enhancement of ecological and evolutionary models. The papers also present current challenges in the applicability of TLS methods and report recent developments in methods facilitating the use of TLS data for research purposes, including automatic processing chains and quantifying branch and above-ground biomass. In this article, we provide an overview of the current and anticipated future capacity of TLS and related methods in solving questions that utilize measurements and models of forests. Conclusions Due to its measurement speed, TLS provides a method to effortlessly capture large amounts of detailed structural forest information, and consequent proxy data for tree and forest processes, at a far wider spatial scale than is feasible with manual measurements. Issues with measurement precision and occlusion of laser beams before they reach their target structures continue to reduce the accuracy of TLS data, but the limitations are counterweighted by the measurement speed that enables large sample sizes. The currently high time-cost of analysing TLS data, in turn, is likely to decrease through progress in automated processing methods. The developments point towards TLS becoming a new and widely accessible standard tool in forest measurement and modelling.


Author(s):  
D. Rissolo ◽  
M. R. Hess ◽  
J. Huchim Herrera ◽  
E. Lo ◽  
V. Petrovic ◽  
...  

<p><strong>Abstract.</strong> Located in the Puuc region of Yucatan, Mexico, the Labyrinth of Oxkintok, also known as Satunsat, is one of the most enigmatic ancient structures in the northern Maya lowlands. Inside this otherwise unremarkable terraced building platform is a series of interconnected vaulted passageways and horizontal ducts that spans three levels. In 2016, we conducted a comprehensive digital documentation of the exterior and interior surfaces and spaces of Satunsat via terrestrial laser scanning (TLS) and structure-from-motion (SfM) photogrammetry. The result is a fused, geometrically accurate, full coverage model with exceptional color and texture fidelity. These data enabled a preliminary structural health assessment and evaluation of the varied masonry techniques employed in the construction of Satunsat and can inform future studies related to the structure’s function and meaning.</p>


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