scholarly journals Interactive Trunk Extraction from Forest Point Cloud

2014 ◽  
Vol XL-5 ◽  
pp. 433-436
Author(s):  
T. Mizoguchi ◽  
Y. Kobayashi
Keyword(s):  
Forest Management ◽  
Point Cloud ◽  
Laser Scanner ◽  
Interactive System ◽  
Terrestrial Laser Scanner ◽  
Diameter At Breast Height ◽  
Breast Height

For forest management or monitoring, it is required to constantly measure several parameters of each tree, such as height, diameter at breast height, and trunk volume. Terrestrial laser scanner has been used for this purpose instead of human workers to reduce time and cost for the measurement. In order to use point cloud captured by terrestrial laser scanner in the above applications, it is an important step to extract all trees or their trunks separately. For this purpose, we propose an interactive system in which a user can intuitively and efficiently extract each trunk by a simple editing on the distance image created from the point cloud. We demonstrate the effectiveness of our proposed system from various experiments.

Individual Tree Parameters Estimation from Terrestrial Laser Scanner Data

2017 ◽  
Author(s):  
Darius Popovas ◽  
Valentas Mikalauskas ◽  
Dominykas Šlikas ◽  
Simonas Valotka ◽  
Tautvydas Šorys
Keyword(s):  
Forest Management ◽  
Laser Scanner ◽  
Tree Height ◽  
Parameters Estimation ◽  
Carbon Accounting ◽  
Terrestrial Laser Scanner ◽  
Individual Tree ◽  
Diameter At Breast Height ◽  
Crown Diameter ◽  
Breast Height

Tree models and information on the various characteristics of trees and forests are required for forest management, city models, carbon accounting and the management of assets. In order to get precise characteristics and information, tree modelling must be done at individual tree level as it represents the interaction process between trees. For sustainable forest management, more information is needed, however, the traditional methods of investigating forest parameters such as, tree height, diameter at breast height, crown diameter, stem curve and stem mapping or tree location are complex and labour-intensive. Light detection and ranging (LiDAR) has been proposed as a suitable technique for mapping of forest biomass. LiDAR can be operated in airborne configuration (Airborne laser scanning) or in a terrestrial setup. Terrestrial Laser Scanner measures forests from below canopy and offers a much more detailed description of the individual trees. The aim of this study is to derive the essential tree parameters for estimation of biomass from terrestrial LiDAR data. Tree height, diameter at breast height, crown diameter, stem curve and tree locations were extracted from Terrestrial Laser Scanner point clouds.

scholarly journals Tree stems from terrestrial laser scanner measurements

2015 ◽  
Vol 63 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Andres Kuusk ◽  
Mait Lang ◽  
Silja Märdla ◽  
Jan Pisek
Keyword(s):  
Point Cloud ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Breast Height ◽  
Tree Layer ◽  
Second Growth ◽  
Spruce Stands ◽  
Dense Grid ◽  
Growth Limits ◽  
Tree Stem

Abstract Terrestrial laser scanner (TLS) measurements were carried out in mature birch, pine, and spruce stands in Järvselja, Estonia. The structure of stands has been previously studied. A simple special clustering procedure is developed for automatic detection of stem positions and estimation of tree stem dimensions from the TLS point cloud. Tree stem diameter at breast height (DBH), vertical profile of stem and size distribution of DBH is estimated with high precision in the pine stand where the second growth tree layer is almost missing. The presence of second growth limits estimating stem dimensions accurately in the birch stand, and the procedure fails in the dense spruce stand of rich undergrowth and low dead branches. In such stands the TLS measurements should be done in dense grid with short-range sounding setup only. The developed procedure is undemanding for computers and can be applied on simple PC-s.

scholarly journals Fitting Terrestrial Laser Scanner Point Clouds with T-Splines: Local Refinement Strategy for Rigid Body Motion

2021 ◽  
Vol 13 (13) ◽  
pp. 2494
Author(s):  
Gaël Kermarrec ◽  
Niklas Schild ◽  
Jan Hartmann
Keyword(s):  
Point Cloud ◽  
Goodness Of Fit ◽  
Laser Scanner ◽  
Point Clouds ◽  
Statistical Testing ◽  
Computational Time ◽  
Terrestrial Laser Scanner ◽  
Reference Surface ◽  
Local Refinement ◽  
Surface Approximation

T-splines have recently been introduced to represent objects of arbitrary shapes using a smaller number of control points than the conventional non-uniform rational B-splines (NURBS) or B-spline representatizons in computer-aided design, computer graphics and reverse engineering. They are flexible in representing complex surface shapes and economic in terms of parameters as they enable local refinement. This property is a great advantage when dense, scattered and noisy point clouds are approximated using least squares fitting, such as those from a terrestrial laser scanner (TLS). Unfortunately, when it comes to assessing the goodness of fit of the surface approximation with a real dataset, only a noisy point cloud can be approximated: (i) a low root mean squared error (RMSE) can be linked with an overfitting, i.e., a fitting of the noise, and should be correspondingly avoided, and (ii) a high RMSE is synonymous with a lack of details. To address the challenge of judging the approximation, the reference surface should be entirely known: this can be solved by printing a mathematically defined T-splines reference surface in three dimensions (3D) and modeling the artefacts induced by the 3D printing. Once scanned under different configurations, it is possible to assess the goodness of fit of the approximation for a noisy and potentially gappy point cloud and compare it with the traditional but less flexible NURBS. The advantages of T-splines local refinement open the door for further applications within a geodetic context such as rigorous statistical testing of deformation. Two different scans from a slightly deformed object were approximated; we found that more than 40% of the computational time could be saved without affecting the goodness of fit of the surface approximation by using the same mesh for the two epochs.

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.

scholarly journals Comparison of Three Algorithms to Estimate Tree Stem Diameter from Terrestrial Laser Scanner Data

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 599 ◽  
Author(s):  
Ravaglia ◽  
Fournier ◽  
Bac ◽  
Véga ◽  
Côté ◽  
...  
Keyword(s):  
Laser Scanner ◽  
Point Clouds ◽  
Stem Diameter ◽  
Trunk Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Forest Inventories ◽  
Laser Scanners ◽  
Step Algorithm ◽  
Coniferous Plantations

Terrestrial laser scanners provide accurate and detailed point clouds of forest plots, which can be used as an alternative to destructive measurements during forest inventories. Various specialized algorithms have been developed to provide automatic and objective estimates of forest attributes from point clouds. The STEP (Snakes for Tuboid Extraction from Point cloud) algorithm was developed to estimate both stem diameter at breast height and stem diameters along the bole length. Here, we evaluate the accuracy of this algorithm and compare its performance with two other state-of-the-art algorithms that were designed for the same purpose (i.e., the CompuTree and SimpleTree algorithms). We tested each algorithm against point clouds that incorporated various degrees of noise and occlusion. We applied these algorithms to three contrasting test sites: (1) simulated scenes of coniferous stands in Newfoundland (Canada), (2) test sites of deciduous stands in Phalsbourg (France), and (3) coniferous plantations in Quebec, Canada. In most cases, the STEP algorithm predicted diameter at breast height with higher R2 and lower RMSE than the other two algorithms. The STEP algorithm also achieved greater accuracy when estimating stem diameter in occluded and noisy point clouds, with mean errors in the range of 1.1 cm to 2.28 cm. The CompuTree and SimpleTree algorithms respectively produced errors in the range of 2.62 cm to 6.1 cm and 1.03 cm to 3.34 cm, respectively. Unlike CompuTree or SimpleTree, the STEP algorithm was not able to estimate trunk diameter in the uppermost portions of the trees. Our results show that the STEP algorithm is more adapted to extract DBH and stem diameter automatically from occluded and noisy point clouds. Our study also highlights that SimpleTree and CompuTree require data filtering and results corrections. Conversely, none of these procedures were applied for the implementation of the STEP algorithm.

scholarly journals Automated low-cost terrestrial laser scanner for measuring diameters at breast height and heights of plantation trees

PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0209888 ◽  
Author(s):  
Pei Wang ◽  
Ronghao Li ◽  
Guochao Bu ◽  
Rui Zhao
Keyword(s):  
Low Cost ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Breast Height

scholarly journals Accuracy Analysis Of Three Dimensional Models Of Building Prof. H. Soedarto S. H. Using The Terrestrial Laser Scanner Technology Based On Traverse Method

Teknik ◽  
2019 ◽  
Vol 39 (2) ◽  
pp. 94
Author(s):  
Yudo Prasetyo
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Accuracy Analysis ◽  
Dimensional Models ◽  
Data Point ◽  
Three Dimensional Models

Teknologi dokumentasi gedung secara spasial untuk konservasi dan perencanaan tata ruang semakin berkembang pesat. Urgensi tingkat ketelitian dalam suatu pengukuran juga dituntut semakin tinggi. Salah satu teknologi pembentukan objek tiga dimensi yang berkembang saat ini adalah Terrestrial Laser Scanner (TLS). Metode pengukuran TLS terdiri atas 4 metode yaitu: Cloud to Cloud, Target to Target, Traverse, dan metode kombinasi. Penelitian ini bertujuan untuk menganalisa tingkat ketelitian metode Traverse dalam pengukuran suatu objek model tiga dimensi untuk keperluan dokumentasi gedung menggunakan TLS.Ketelitian metode Traverse akan diujikan pada Gedung Prof. H. Soedarto, S. H. Tingkat ketelitiannya diujikan pada dua parameter yakni hasil metode registrasi dan hasil visualisasi model tiga dimensi. Hasil analisis pengolahan data point cloud menunjukkan bahwa alat TLS dengan metode Traverse dapat digunakan untuk menghasilkan model tiga dimensi Gedung Prof. Sudarto, S. H. Nilai rata-rata validasi yang diperoleh adalah sebesar 0,004 meter dengan besaran ketelitian model RMSE sebesar ±0,00611 meter. 

Structure Deformation Measurement with Terrestrial Laser Scanner at Pathein Bridge in Myanmar

2018 ◽  
Vol 13 (1) ◽  
pp. 40-49 ◽  
Author(s):  
Nuntikorn Kitratporn ◽  
◽  
Wataru Takeuchi ◽  
Koji Matsumoto ◽  
Kohei Nagai
Keyword(s):  
Point Cloud ◽  
Cloud Model ◽  
Laser Scanner ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Terrestrial Laser Scanner ◽  
Bridge Structure ◽  
Surface Geometry ◽  
Deformation State ◽  
Measurement Results

In Myanmar, defects and possible deformation were reported in many long-span suspension bridges. The current state of bridge infrastructure must be inspected, so that deterioration can be stalled and failure can be prevented. A 3D laser scanner, specifically the terrestrial laser scanner (TLS), has demonstrated the ability to capture surface geometry with millimeter accuracy. Consequently, TLS technology has received significant interest in various applications including in the field of structural survey. However, research on its application in large bridge structure remains limited. This study examines the use of TLS point cloud for the measurement of three deformation behaviors at the Pathein Suspension Bridge in Myanmar. These behaviors include tower inclination, hanger inclination, and deflection of bridge truss. The measurement results clearly captured the deformation state of the bridge. A comparison of the measurement results with available conventional measurements yielded overall agreement. However, errors were observed in some areas, which could be due to noise and occlusion in the point cloud model. In this study, the advantages of TLS in providing non-discrete data, direct measurement in meaningful unit, and access to difficult-to-access sections, such as top of towers or main cables, were demonstrated. The limitations of TLS as observed in this study were mainly influenced by external factors during field survey. Hence, it was suggested that further study on appropriate TLS surveying practice for large bridge structure should be conducted.

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