scholarly journals A Method to Obtain Orange Crop Geometry Information Using a Mobile Terrestrial Laser Scanner and 3D Modeling

2017 ◽  
Vol 9 (8) ◽  
pp. 763 ◽  
Author(s):  
André Colaço ◽  
Rodrigo Trevisan ◽  
José Molin ◽  
Joan Rosell-Polo ◽  
Alexandre Escolà
Author(s):  
G. J. Grenzdörffer ◽  
M, Naumann ◽  
F. Niemeyer ◽  
A. Frank

In this contribution the possibility to combine terrestrial laser scanner (TLS) measurements and UAS photogrammetry for the detailed description and high quality surveying of a cultural monument will be illustrated by the example of the Cathedral of St. Nicholas in the city of Greifswald. Due to the different nature of UAS photogrammetry and TLS walls and windows as well as portions of roofs are captured with a different level of completeness and accuracy. The average deviations of the test areas on the overlap between the two measurement methods ranges from 0.015 m to 0.033 m with standard deviations of 0.025 m to 0.088 m.


Author(s):  
Cecilia Maria Bolognesi ◽  
Fausta Fiorillo

The integration of close-range photogrammetry and terrestrial laser scanner enables reality-based modeling procedures that can help BIM modeling for existing buildings. The restitution of virtual models from high-resolution surveys is a complex process that requires much expertise. It incorporates concepts of resolution, accuracy, and precision in the acquisition phase; filtering, registration, and decimation for point cloud elaboration; and meshing, texturing, simplification, segmentation, and feature extraction in the final modeling stage. The previous steps are the same whether the ultimate goal is a classic 2D representation or a 3D one. For BIM modeling, the job becomes challenging because the necessary simplification of the model cannot be automatized and apparently collides with the high resolution and fidelity of original surveyed data. This chapter presents the process of surveying and 3D modeling of the Ghesc village, following the whole path from data acquisition to BIM modeling, discussing strengths and weakness, issues, and recent solutions for restoration interventions.


2013 ◽  
Vol 748 ◽  
pp. 1119-1124
Author(s):  
Ying Zhang ◽  
Hang Chen ◽  
Zhi Qiang Du

The main idea of this paper is to describe the application of Terrestrial Laser Scanner in 3D modeling. Considering the special terrain structure of underground geological park, a 3D modeling procedure based on Terrestrial Laser Scanner is designed. The graphs of vertical cross-section and horizontal cross-section are achieved after model optimization. Experiments show that the method can work better than Ground-based measurements in 3D modeling of underground geological park. The 3D model of underground geological park can be used to monitor the amount of mining and get the graphs of vertical cross-section and horizontal cross-section, which will be applied widely in future.


Author(s):  
Nikolay Lugovoy ◽  
Nikolay Lugovoy ◽  
Askar Ilyasov ◽  
Askar Ilyasov ◽  
Elena Pronina ◽  
...  

The paper describes application of the terrestrial laser scanner for investigation of coastal dynamics of the Svetlogorskaya Bay, Baltic Sea. Methods of investigation and results of surveys repeated over the two consecutive years for quantification of coastal erosion and slope processes within the coastal zone are presented.


2020 ◽  
Author(s):  
Collin Megee ◽  
◽  
Michael O'Neal ◽  
Joseph Clemens ◽  
Erica McMaster ◽  
...  

2021 ◽  
Vol 13 (13) ◽  
pp. 2494
Author(s):  
Gaël Kermarrec ◽  
Niklas Schild ◽  
Jan Hartmann

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.


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