Artículos de revistas: "Portable Laser Scanner"

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Duan, Xuzhe, Qingwu Hu, Pengcheng Zhao y Shaohua Wang. "A Low-Cost and Portable Indoor 3D Mapping Approach Using Biaxial Line Laser Scanners and a One-Dimension Laser Range Finder Integrated with Microelectromechanical Systems". Photogrammetric Engineering & Remote Sensing 88, n.º 5 (1 de mayo de 2022): 311–21. http://dx.doi.org/10.14358/pers.21-00037r2.

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Existing indoor 3D mapping solutions suffer from high cost and poor portability. In this article, a low-cost and portable indoor 3D mapping approach using biaxial line laser scanners and a one-dimension laser range finder integrated with microelectromechanical systems is proposed. A multiple-sensor calibration approach is presented to perform the extrinsic calibration of the integrated 3D mapping system. The 2D point cloud acquired by the horizontal laser scanner and the orientation information obtained by the microelectromechanical systems are used as inputs for a simultaneous localization and mapping framework to estimate the 2D poses. The height information acquired by the laser range finder is then fused to obtain the 3D pose, which is applied to restore the actual position and orientation of the 2D point cloud generated by the tilted laser scanner to reconstruct the 3D point cloud of the indoor environment. The experimental results—three typical indoor scenes—demonstrate that the proposed approach can achieve accuracies of 3 cm and 2°. Therefore, the proposed approach is a low-cost, portable, and accurate solution for indoor 3D mapping.

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Hambling, David. "Portable laser scanner creates 3D images in colour". New Scientist 253, n.º 3370 (enero de 2022): 9. http://dx.doi.org/10.1016/s0262-4079(22)00077-x.

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Huang, Chi-hua y Joe M. Bradford. "Portable Laser Scanner for Measuring Soil Surface Roughness". Soil Science Society of America Journal 54, n.º 5 (septiembre de 1990): 1402–6. http://dx.doi.org/10.2136/sssaj1990.03615995005400050032x.

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Xu, Ning, Wei Zhang, Liye Zhu, Changqing Li y Shifeng Wang. "Object 3D surface reconstruction approach using portable laser scanner". IOP Conference Series: Earth and Environmental Science 69 (junio de 2017): 012119. http://dx.doi.org/10.1088/1755-1315/69/1/012119.

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Mor Cases, Sergi, Kittiphot Jianwattananukul, Khanuengchat Saenyot, Sarai Lekchaum y Kitsakorn Locharoenrat. "Portable laser 1-D barcode scanner for material identification". Materials Today: Proceedings 5, n.º 7 (2018): 15143–48. http://dx.doi.org/10.1016/j.matpr.2018.04.072.

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Watanabe, Takuma, Takeru Niwa y Hiroshi Masuda. "Registration of Point-Clouds from Terrestrial and Portable Laser Scanners". International Journal of Automation Technology 10, n.º 2 (4 de marzo de 2016): 163–71. http://dx.doi.org/10.20965/ijat.2016.p0163.

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We proposed a registration method for aligning short-range point-clouds captured using a portable laser scanner (PLS) to a large-scale point-cloud captured using a terrestrial laser scanner (TLS). As a PLS covers a very limited region, it often fails to provide sufficient features for registration. In our method, the system analyzes large-scale point-clouds captured using a TLS and indicates candidate regions to be measured using a PLS. When the user measures a suggested region, the system aligns the captured short-range point-cloud to the large-scale point-cloud. Our experiments show that the registration method can adequately align point-clouds captured using a TLS and a PLS.

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HAYAKAWA, Yoshiaki, Yoshiharu ASANO, Hideki TAKAMURA y Hiroyuki NAKAMURA. "ESTIMATION OF FOREST RESOURCES FROM PORTABLE 3D LASER SCANNER DATA". Journal of Architecture and Planning (Transactions of AIJ) 79, n.º 703 (2014): 2109–16. http://dx.doi.org/10.3130/aija.79.2109.

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Thilmany, Jean. "Outside In". Mechanical Engineering 131, n.º 08 (1 de agosto de 2009): 38–41. http://dx.doi.org/10.1115/1.2009-aug-5.

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This article discusses reverse engineering software is slowly changing the way design engineers do their everyday jobs. With the pervasiveness of computer-aided design packages, reverse engineering technology has become a practical tool to create a 3D virtual model of an existing physical part. This model is then available to be used in 3D CAD, computer-aided manufacturing, or other computer-aided engineering applications. The reverse engineering process needs hardware and software that work together. The hardware is used to measure an object, and the software reconstructs it as a 3D model. The physical object can be measured using 3D scanning technologies such as a coordinate measuring machine, laser scanner, structured light digitizer, or computed tomography. The wider accessibility of handheld-laser scanners and portable CMMs like the one used at Excel Foundry means more companies can afford reverse engineering for their own unique ends. The scanner has turned out to be equally useful for engineering and for local archeological and preservation projects; and so far, it has been used to help preserve endangered artifacts.

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Hu, Chang’an, Song Hu, Linghui Kong y Junbo Liu. "Application of ground laser scanner in surveying and mapping field". Journal of Physics: Conference Series 2029, n.º 1 (1 de septiembre de 2021): 012080. http://dx.doi.org/10.1088/1742-6596/2029/1/012080.

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Abstract With the continuous development of measurement demand, the market of single point measurement mode is shrinking, 3D measurement is more and more appearing in the field of surveying and mapping, ground laser scanner as a portable 3D measurement tool, its use is more and more important. This paper takes substation measurement, cadastral measurement, facade measurement and oil tank measurement as typical cases, and introduces the case of oil tank measurement in detail.

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Nüchter, A., D. Borrmann, P. Koch, M. Kühn y S. May. "A MAN-PORTABLE, IMU-FREE MOBILE MAPPING SYSTEM". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-3/W5 (19 de agosto de 2015): 17–23. http://dx.doi.org/10.5194/isprsannals-ii-3-w5-17-2015.

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Mobile mapping systems are commonly mounted on cars, ships and robots. The data is directly geo-referenced using GPS data and expensive IMU (inertial measurement systems). Driven by the need for flexible, indoor mapping systems we present an inexpensive mobile mapping solution that can be mounted on a backpack. It combines a horizontally mounted 2D profiler with a constantly spinning 3D laser scanner. The initial system featuring a low-cost MEMS IMU was revealed and demonstrated at MoLaS: Technology Workshop Mobile Laser Scanning at Fraunhofer IPM in Freiburg in November 2014. In this paper, we present an IMU-free solution.

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Elseicy, Ahmed, Shayan Nikoohemat, Michael Peter y Sander Oude Elberink. "Space Subdivision of Indoor Mobile Laser Scanning Data Based on the Scanner Trajectory". Remote Sensing 10, n.º 11 (15 de noviembre de 2018): 1815. http://dx.doi.org/10.3390/rs10111815.

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State-of-the-art indoor mobile laser scanners are now lightweight and portable enough to be carried by humans. They allow the user to map challenging environments such as multi-story buildings and staircases while continuously walking through the building. The trajectory of the laser scanner is usually discarded in the analysis, although it gives insight about indoor spaces and the topological relations between them. In this research, the trajectory is used in conjunction with the point cloud to subdivide the indoor space into stories, staircases, doorways, and rooms. Analyzing the scanner trajectory as a standalone dataset is used to identify the staircases and to separate the stories. Also, the doors that are traversed by the operator during the scanning are identified by processing only the interesting spots of the point cloud with the help of the trajectory. Semantic information like different space labels is assigned to the trajectory based on the detected doors. Finally, the point cloud is semantically enriched by transferring the labels from the annotated trajectory to the full point cloud. Four real-world datasets with a total of seven stories are used to evaluate the proposed methods. The evaluation items are the total number of correctly detected rooms, doors, and staircases.

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Graciano, Alejandro, Lidia Ortega, Rafael J. Segura y Francisco R. Feito. "Digitization of religious artifacts with a structured light scanner". Virtual Archaeology Review 8, n.º 17 (26 de julio de 2017): 49. http://dx.doi.org/10.4995/var.2016.4650.

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The digitization process for religious artifacts is subject to inherent difficulties often ignored in theoretical models or pipelines. In this paper we aim to describe these problems, which are present in practical environments such as temples and churches, using white light scanners instead of other common devices or technologies such as laser scanners and photogrammetry. Our case study is based on the digitization of two religious statues belonging to a Catholic brotherhood located in a village of the Province of Jaén (Spain), one of them presenting especially several limitations. After performing the scanning process with a portable hand-held scanner, the images captured were processed until the final models were acquired. On the basis of the results obtained, we discuss the problems arising after using well-known procedures for the reconstruction of 3D models, their causes and some possible solutions to achieving a correct digitization. It should be noted that it is not the aim of this study to establish procedures for the digitization of religious artifacts, but rather to transmit the inherent constraints of these types of scenes.

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Chen, Chao, Llewellyn Tang, Craig Matthew Hancock y Penghe Zhang. "Development of low-cost mobile laser scanning for 3D construction indoor mapping by using inertial measurement unit, ultra-wide band and 2D laser scanner". Engineering, Construction and Architectural Management 26, n.º 7 (19 de agosto de 2019): 1367–86. http://dx.doi.org/10.1108/ecam-06-2018-0242.

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Purpose The purpose of this paper is to introduce the development of an innovative mobile laser scanning (MLS) method for 3D indoor mapping. The generally accepted and used procedure for this type of mapping is usually performed using static terrestrial laser scanning (TLS) which is high-cost and time-consuming. Compared with conventional TLS, the developed method proposes a new idea with advantages of low-cost, high mobility and time saving on the implementation of a 3D indoor mapping. Design/methodology/approach This method integrates a low-cost 2D laser scanner with two indoor positioning techniques – ultra-wide band (UWB) and an inertial measurement unit (IMU), to implement a 3D MLS for reality captures from an experimental indoor environment through developed programming algorithms. In addition, a reference experiment by using conventional TLS was also conducted under the same conditions for scan result comparison to validate the feasibility of the developed method. Findings The findings include: preset UWB system integrated with a low-cost IMU can provide a reliable positioning method for indoor environment; scan results from a portable 2D laser scanner integrated with a motion trajectory from the IMU/UWB positioning approach is able to generate a 3D point cloud based in an indoor environment; and the limitations on hardware, accuracy, automation and the positioning approach are also summarized in this study. Research limitations/implications As the main advantage of the developed method is low-cost, it may limit the automation of the method due to the consideration of the cost control. Robotic carriers and higher-performance 2D laser scanners can be applied to realize panoramic and higher-quality scan results for improvements of the method. Practical implications Moreover, during the practical application, the UWB system can be disturbed by variances of the indoor environment, which can affect the positioning accuracy in practice. More advanced algorithms are also needed to optimize the automatic data processing for reducing errors caused by manual operations. Originality/value The development of this MLS method provides a novel idea that integrates data from heterogeneous systems or sensors to realize a practical aim of indoor mapping, and meanwhile promote the current laser scanning technology to a lower-cost, more flexible, more portable and less time-consuming trend.

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Tommaselli, A. M. G. y F. M. Torres. "A LIGHT-WEIGHT LASER SCANNER FOR UAV APPLICATIONS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (6 de junio de 2016): 711–15. http://dx.doi.org/10.5194/isprs-archives-xli-b1-711-2016.

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Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

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Tommaselli, A. M. G. y F. M. Torres. "A LIGHT-WEIGHT LASER SCANNER FOR UAV APPLICATIONS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (6 de junio de 2016): 711–15. http://dx.doi.org/10.5194/isprsarchives-xli-b1-711-2016.

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Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

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Hosseininaveh, A., R. Yazdan, A. Karami, M. Moradi y F. Ghorbani. "A LOW-COST AND PORTABLE SYSTEM FOR 3D RECONSTRUCTION OF TEXTURE-LESS OBJECTS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-1-W5 (11 de diciembre de 2015): 327–32. http://dx.doi.org/10.5194/isprsarchives-xl-1-w5-327-2015.

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The optical methods for 3D modelling of objects can be classified into two categories including image-based and range-based methods. Structure from Motion is one of the image-based methods implemented in commercial software. In this paper, a low-cost and portable system for 3D modelling of texture-less objects is proposed. This system includes a rotating table designed and developed by using a stepper motor and a very light rotation plate. The system also has eight laser light sources with very dense and strong beams which provide a relatively appropriate pattern on texture-less objects. In this system, regarding to the step of stepper motor, images are semi automatically taken by a camera. The images can be used in structure from motion procedures implemented in Agisoft software.To evaluate the performance of the system, two dark objects were used. The point clouds of these objects were obtained by spraying a light powders on the objects and exploiting a GOM laser scanner. Then these objects were placed on the proposed turntable. Several convergent images were taken from each object while the laser light sources were projecting the pattern on the objects. Afterward, the images were imported in VisualSFM as a fully automatic software package for generating an accurate and complete point cloud. Finally, the obtained point clouds were compared to the point clouds generated by the GOM laser scanner. The results showed the ability of the proposed system to produce a complete 3D model from texture-less objects.

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Ion, Rodica-Mariana, Valentin Gurgu, Ioan Alin Bucurica, Sofia Teodorescu, Mihaela-Lucia Ion, Dana Postolache y Ioan Darida. "3D-Reconstruction of the Complex Stuccoes from Patrimony Buildings". Digital Presentation and Preservation of Cultural and Scientific Heritage 7 (10 de septiembre de 2017): 107–12. http://dx.doi.org/10.55630/dipp.2017.7.9.

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The paper deals with 3D scanning techniques and instruments to survey the complex stuccoes from the architectural building Nanu-Muscel from Bucharest. EXAscan Portable 3D Laser Scanner has been used to exploit the advantages of the 3D surveying techniques and produce digital models and other geometric representations useful for the protection of historic architectures and a correct solution for their restoration. After the parameterization, the scanning of two stucco-objects surface yielded to a network of points. The program analyzes the points and joins them, so the final result being the scanned object in electronic format (digitized), by "Digitized Shape Editor" module in the Catia program. The not useful surfaces have been removed and for the symmetrical reconstruction the mirroring operation was applied.

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Torres, Fernanda Magri y Antonio Maria Garcia Tommaselli. "A LIGHTWEIGHT UAV-BASED LASER SCANNING SYSTEM FOR FOREST APPLICATION". Boletim de Ciências Geodésicas 24, n.º 3 (agosto de 2018): 318–34. http://dx.doi.org/10.1590/s1982-21702018000300021.

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Abstract Lightweight Unmanned Aerial Vehicles (UAVs) have become a cost effective alternative for studies which use aerial Remote Sensing with high temporal frequency requirements for small areas. Laser scanner devices are widely used for rapid tridimensional data acquisition, mainly as a complementary data source to photogrammetric surveying. Recent studies using laser scanner systems onboard UAVs for forestry inventory and mapping applications have presented encouraging results. This work describes the development and accuracy assessment of a low cost mapping platform composed by an Ibeo Lux scanner, a GNSS (Global Navigation Satellite System) antenna, an Inertial Navigation System Novatel Span-IGM-S1, integrating a GNSS receiver and an IMU (Inertial Measurement Unit), a Raspberry PI portable computer and an octopter UAV. The system was assessed in aerial mode using an UAV octopter developed by SensorMap Company. The resulting point density in a plot with trees concentration was also evaluated. The point density of this device is lower than conventional Airborne Laser Systems but the results showed that altimetric accuracy with this system is around 30 cm, which is acceptable for forest applications. The main advantages of this system are their low weight and low cost, which make it attractive for several applications.

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Lin, Yu-Chieh, Yen-Yin Lin, Yu-Hsiang Huang y An-Chung Chiang. "A compact and portable laser radioactive decontamination system using passive Q-switched fiber laser and polygon scanner". Applied Radiation and Isotopes 153 (noviembre de 2019): 108835. http://dx.doi.org/10.1016/j.apradiso.2019.108835.

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KUBOTA, Satoshi, Yoshinori TSUKADA, Shigenori TANAKA, Yoshimasa UMEHARA, Masaya NAKAHARA y Takuma IIDA. "SURVEY AND DESIGN OF PORTABLE LASER SCANNER FOR MEASURING THREE-DIMENSIONAL DATA ON STRUCTURES". Journal of Japan Society of Civil Engineers, Ser. F3 (Civil Engineering Informatics) 75, n.º 2 (2019): II_105—II_113. http://dx.doi.org/10.2208/jscejcei.75.2_ii_105.

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Barsky, Victor, Alexander Perov, Sergei Tokalov, Alexander Chudinov, Edward Kreindlin, Alexei Sharonov, Ekaterina Kotova y Andrei Mirzabekov. "Fluorescence Data Analysis on Gel-Based Biochips". Journal of Biomolecular Screening 7, n.º 3 (junio de 2002): 247–57. http://dx.doi.org/10.1177/108705710200700308.

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A series of biochip readers developed for gel-based biochips includes three imaging models and a novel nonimaging biochip scanner. The imaging readers, ranging from a research-grade versatile reader to a simple portable one, use wide-field objectives and 12-bit digital large-coupled device cameras for parallel addressing of multiple array elements. This feature is valuable for monitoring the kinetics of sample interaction with immobilized probes. Depending on the model and the label used, the sensitivity of these readers approaches 0.3 amol of a labeled sample per gel element. In the selective scanner, both the spot size of the excitation laser beam and the detector field of view match the size of the biochip array elements so that the whole row of the array can be read in a single scan. The portable version reads 50-mm long, 150-element, one-dimensional arrays in 5 s. With a dynamic range of 4000:1, a sensitivity of 1-5 amol of a labeled sample per gel element, and a data format facilitating online processing, the scanner is an attractive, inexpensive solution for biomedical diagnostics. Fluorophores for sample labeling were compared experimentally in terms of detection sensitivity, influence on duplex stability, and suitability for multilabel analysis and thermodynamic studies. Texas Red and tetracarboxyphenylporphyn proved to be the best choice for two-wavelength analysis using the imaging readers.

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Giuffrida, Dario, Viviana Mollica Nardo, Daniela Neri, Giovanni Cucinotta, Irene Vittoria Calabrò, Loredana Pace y Rosina Celeste Ponterio. "Terrestrial laser scanning for the modelling of indoor archaeological areas: two case-studies from Reggio Calabria, Italy". Journal of Physics: Conference Series 2204, n.º 1 (1 de abril de 2022): 012075. http://dx.doi.org/10.1088/1742-6596/2204/1/012075.

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Abstract The work shows the application of a portable terrestrial laser scanner for the three-dimensional survey and modelling of two archaeological areas preserved in the urban fabric of Reggio Calabria, Italy: the underground site of Piazza Italia, better known as “Ipogeo”, and the ruins of the s.c. odéon, located in the basement of a residential building in via 24 Maggio. The two case studies, compared to the other sites preserved in the city center, share a common element: they are not outdoors but have been incorporated into modern buildings and therefore they are not immediately visible. Due to the specific features of the sites, the use of a portable laser-scanning system has been considered the most suitable, accurate and quick solution in order to produce high-resolution as-built 3d models of the structures. The latter will be used as support to derive plans and sections, to carry out further virtual reconstructions and to plan a scan-to-bim process.

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Li, Jianfeng, Ming Chen, Xuebi Jin, Yu Chen, Zhiyong Dai, Zhonghua Ou y Qin Tang. "Calibration of a multiple axes 3-D laser scanning system consisting of robot, portable laser scanner and turntable". Optik 122, n.º 4 (febrero de 2011): 324–29. http://dx.doi.org/10.1016/j.ijleo.2010.02.014.

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Cobos, Santiago Fabian, Christopher James Norley, Steven Ingo Pollmann y David Wayne Holdsworth. "Cost-effective micro-CT system for non-destructive testing of titanium 3D printed medical components". PLOS ONE 17, n.º 10 (10 de octubre de 2022): e0275732. http://dx.doi.org/10.1371/journal.pone.0275732.

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Micro-CT imaging can be used as an effective method for non-destructive testing (NDT) of metal 3D printed parts–including titanium biomedical components fabricated using laser powder-bed-fusion (LPBF). Unfortunately, the cost of commercially available micro-CT scanners renders routine NDT for biomedical applications prohibitively expensive. This study describes the design, manufacturing, and implementation of a cost-effective scanner tailored for NDT of medium-size titanium 3D printed biomedical components. The main elements of the scanner; which include a low-energy (80 kVp) portable x-ray unit, and a low-cost lens-coupled detector; can be acquired with a budget less than $ 11000 USD. The low-cost detector system uses a rare-earth phosphor screen, lens-coupled to a dSLR camera (Nikon D800) in a front-lit tilted configuration. This strategy takes advantage of the improved light-sensitivity of modern full-frame CMOS camera sensors and minimizes source-to-detector distance to maximize x-ray flux. The imaging performance of the system is characterized using a comprehensive CT quality-assurance phantom, and two titanium 3D-printed test specimens. Results show that the cost-effective scanner can survey the porosity and cracks in titanium parts with thicknesses of up to 13 mm of solid metal. Quantitatively, the scanner produced geometrically stable reconstructions, with a voxel size of 118 μm, and noise levels under 55 HU. The cost-effective scanner was able to estimate the porosity of a 17 mm diameter titanium 3D-printed cylindrical lattice structure, with a 0.3% relative error. The proposed scanner will facilitate the implementation of titanium LPBF-printed components for biomedical applications by incorporating routine cost-effective NDT as part of the process control and validation steps of medical-device quality-management systems. By reducing the cost of the x-ray detector and shielding, the scan cost will be commensurate with the overall cost of the validated component.

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Galeazzi, Fabrizio, Holley Moyes y Mark Aldenderfer. "Defining Best 3D Practices in Archaeology". Advances in Archaeological Practice 2, n.º 4 (noviembre de 2014): 353–65. http://dx.doi.org/10.7183/2326-3768.2.4.353.

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AbstractThis research aims to investigate the potential use of three-dimensional (3D) technologies for the analysis and interpretation of heritage sites. This article uses different 3D survey technologies to find the most appropriate methods to document archaeological stratigraphy, based on diverse environmental conditions, light exposures, and varied surfaces. The use of 3D laser scanners and dense stereo matching (DSM) techniques is now well established in archaeology. However, no convincing comparisons between those techniques have been presented. This research fills this gap to provide an accurate data assessment for the Las Cuevas site (Belize) and represents a starting point for the definition of a sharable methodology. Tests in Las Cuevas were conducted to compare both accuracy and density reliability in cave environments using two different techniques: triangulation light laser scanner and DSM. This study finds that DSM is the most economical, portable, and flexible approach for the 3D documentation of archaeological sites today. In fact, DSM allows the 3D documentation process to be done more efficiently, reducing both data acquisition and processing time. Nonetheless, the quantitative comparison presented in this paper underscores the need to integrate this technique with other technologies when the data acquisition of micro-stratigraphy is required.

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Morales, Edith Obregón, Jose de Jesus Perez Bueno, Juan Carlos Moctezuma Esparza, Diego Marroquín García, Arturo Trejo Perez, Roberto Carlos Flores Romero, Juan Manuel Olivares Ramírez et al. "Portable Hybrid Refrigerator Prototype for Agribusiness With Its 3D Real Physical Geometry Scanned and Transferred for Simulation Software". International Journal of Hyperconnectivity and the Internet of Things 5, n.º 1 (enero de 2021): 78–97. http://dx.doi.org/10.4018/ijhiot.2021010105.

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A methodology that starts from the acquisition of real prototype geometries up to simulations to evaluate parameters, improvements, or performance under various conditions is proposed. The authors show a case study of a refrigerator with storage capacity for 50 kg of fruit solar-powered by photovoltaic panels, which reach a temperature of about 4°C. The refrigerator comprises two systems, vapor-compression, and Peltier. The methodology consisted of acquiring by a 3D laser scanner or coordinate measuring machine (CMM) and in some small complex items using 3D photogrammetry scanner. These data were transferred first as a CAD or solid works geometry and subsequently transferred to domains geometry useful for ANSYS or COMSOL simulation software. These models with high-resolution bring the simulations closer to real prototypes. Wireless sensors were installed for temperature and humidity monitoring. The analyses of the energy efficiencies of the prototype were performed. The photovoltaic system was for use in crop areas where there was no access to the urban electric network.

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Jamayet, Nafij Bin, Johari Yap Abdullah, Ahmed Mushfiqur Rahman, Adam Husein y Mohammad Khursheed Alam. "A fast and improved method of rapid prototyping for ear prosthesis using portable 3D laser scanner". Journal of Plastic, Reconstructive & Aesthetic Surgery 71, n.º 6 (junio de 2018): 946–53. http://dx.doi.org/10.1016/j.bjps.2018.02.003.

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Li, Jianfeng, Yongkang Guo, Jianhua Zhu, Xiangdi Lin, Yao Xin, Kailiang Duan y Qing Tang. "Large depth-of-view portable three-dimensional laser scanner and its segmental calibration for robot vision". Optics and Lasers in Engineering 45, n.º 11 (noviembre de 2007): 1077–87. http://dx.doi.org/10.1016/j.optlaseng.2007.05.006.

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Díaz-Vilariño, L., E. Verbree, S. Zlatanova y A. Diakité. "INDOOR MODELLING FROM SLAM-BASED LASER SCANNER: DOOR DETECTION TO ENVELOPE RECONSTRUCTION". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W7 (12 de septiembre de 2017): 345–52. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w7-345-2017.

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Updated and detailed indoor models are being increasingly demanded for various applications such as emergency management or navigational assistance. The consolidation of new portable and mobile acquisition systems has led to a higher availability of 3D point cloud data from indoors. In this work, we explore the combined use of point clouds and trajectories from SLAM-based laser scanner to automate the reconstruction of building indoors. The methodology starts by door detection, since doors represent transitions from one indoor space to other, which constitutes an initial approach about the global configuration of the point cloud into building rooms. For this purpose, the trajectory is used to create a vertical point cloud profile in which doors are detected as local minimum of vertical distances. As point cloud and trajectory are related by time stamp, this feature is used to subdivide the point cloud into subspaces according to the location of the doors. The correspondence between subspaces and building rooms is not unambiguous. One subspace always corresponds to one room, but one room is not necessarily depicted by just one subspace, for example, in case of a room containing several doors and in which the acquisition is performed in a discontinue way. The labelling problem is formulated as combinatorial approach solved as a minimum energy optimization. Once the point cloud is subdivided into building rooms, envelop (conformed by walls, ceilings and floors) is reconstructed for each space. The connectivity between spaces is included by adding the previously detected doors to the reconstructed model. The methodology is tested in a real case study.

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OGAWA, Yasuhiro, Wataru MURAKAMI y Koji TAMAI. "A method for measuring the shape of a wooden check dam using a portable terrestrial laser scanner". Journal of the Japanese Society of Revegetation Technology 47, n.º 1 (31 de agosto de 2021): 165–68. http://dx.doi.org/10.7211/jjsrt.47.165.

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Li, Jianfeng, Jianhua Zhu, Yongkang Guo, Xiangdi Lin, Kailiang Duan, Yishan Wang y Qing Tang. "Calibration of a portable laser 3-D scanner used by a robot and its use in measurement". Optical Engineering 47, n.º 1 (2008): 017202. http://dx.doi.org/10.1117/1.2829766.

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32

Pryor, Homer L., Thomas A. Furness y Erik Viirre. "Demonstration of the Virtual Retinal Display: A New Display Technology Using Scanned Laser Light". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 42, n.º 16 (octubre de 1998): 1149. http://dx.doi.org/10.1177/154193129804201609.

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The Virtual Retinal Display (VRD) is a new display technology that scans modulated low energy laser light directly onto the viewer's retina to create a perception of a virtual image. This approach provides an unprecedented way to stream photons to the receptors of the eye, affording higher resolution, increased luminance, and potentially a wider field-of-view than previously possible in head coupled displays. The VRD uses video signals from a graphics board or a video camera to modulate low power coherent light from a red laser diode. A mechanical resonant scanner and galvanometer mirror then scan the photon stream from the laser diode in two dimensions through reflective elements and semitransparent combiner such that a raster of light is imaged on the retina. The pixels produced on the retina have no persistence, yet they create the perception of a brilliant full color, and flicker-free virtual image. Developmental models of the VRD have been shown to produce VGA and SVGA image quality. This demonstration exhibits the portable monochrome VRD

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33

Giuffrida, Dario, Viviana Mollica Nardo, Oreste Adinolfi, Maria Amalia Mastelloni y Rosina Celeste Ponterio. "A theatrical double-faced mask preserved at the Museum of Lipari (Messina): study and 3D reconstruction through portable equipment". Virtual Archaeology Review 12, n.º 24 (19 de enero de 2021): 39. http://dx.doi.org/10.4995/var.2021.13916.

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The new tools for 3D survey and modelling (as portable scanners and software packages), often in combination with diagnostics, are nowadays able to provide indispensable elements for the study of archaeological artefacts; their applications to museum’s heritage can be also useful to integrate the traditional graphic documentation and contribute to enhancement and dissemination. This paper shows the benefit of using the aforementioned tools to study the peculiar clay mask No. 11114-E, discovered in 1973 in the Greek necropolis of Lipára, inside tomb No. 1558. The specimen, now exhibited in the Classical Section of the Aeolian Museum, is considered unique both in the Aeolian Islands and in the ancient Greek world, as it is the only one merging two half faces attributable to different characters. This feature, unknown at the time of discovery, has been highlighted in 2018, thanks to a restoration intervention by which a hard concretion layer covering a large portion of the mask surface was removed, bringing to light a smiling young half-face next to an old one with Silenic features. In 2019, the mask was surveyed in situ through a portable and performing laser-scanner arm (the QuantumTM FaroArm by FARO) to produce a high-resolution 3D model useful to enhance the reading of the two halves (not evident enough, due to its state of preservation). The data processing was performed using the Geomagic Wrap software, able to align and merge multiple scans into a single model and to export results in multiple formats, easily shareable and viewable in free software or via the web. Finally, thanks to this method, the successful generation of a digital replica was performed; the resulting replica is useful for dissemination and as a support for the hypothetical reconstruction of the two prototypes taken as models by the craftsman who created the mask.Highlights:<ul><li>A 'mobile laboratory’ consisting of portable equipment has been set up to perform 3D metric surveys on a selection of artefacts preserved at the Museum of Lipari.</li><li>By means of an ultra-precision laser-scanner arm, a 3D survey on a miniaturistic double-faced mask, belonging to the classical theatrical terracotta, has been performed.</li><li>A geometrically accurate and realistic 3D final model has been created. This helped the study and reconstruction of the two characters composing the mask.</li></ul>

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Kohira, K. y H. Masuda. "POINT-CLOUD COMPRESSION FOR VEHICLE-BASED MOBILE MAPPING SYSTEMS USING PORTABLE NETWORK GRAPHICS". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2/W4 (13 de septiembre de 2017): 99–106. http://dx.doi.org/10.5194/isprs-annals-iv-2-w4-99-2017.

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A mobile mapping system is effective for capturing dense point-clouds of roads and roadside objects．Point-clouds of urban areas, residential areas, and arterial roads are useful for maintenance of infrastructure, map creation, and automatic driving. However, the data size of point-clouds measured in large areas is enormously large. A large storage capacity is required to store such point-clouds, and heavy loads will be taken on network if point-clouds are transferred through the network. Therefore, it is desirable to reduce data sizes of point-clouds without deterioration of quality. In this research, we propose a novel point-cloud compression method for vehicle-based mobile mapping systems. In our compression method, point-clouds are mapped onto 2D pixels using GPS time and the parameters of the laser scanner. Then, the images are encoded in the Portable Networking Graphics (PNG) format and compressed using the PNG algorithm. In our experiments, our method could efficiently compress point-clouds without deteriorating the quality.

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35

Giannetti, Francesca, Gherardo Chirici, Davide Travaglini, Francesca Bottalico, Enrico Marchi y Martina Cambi. "Assessment of Soil Disturbance Caused by Forest Operations by Means of Portable Laser Scanner and Soil Physical Parameters". Soil Science Society of America Journal 81, n.º 6 (19 de octubre de 2017): 1577–85. http://dx.doi.org/10.2136/sssaj2017.02.0051.

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36

Rodríguez-Martín, Rodríguez-Gonzálvez, Ruiz de Oña Crespo y González-Aguilera. "Validation of Portable Mobile Mapping System for Inspection Tasks in Thermal and Fluid–Mechanical Facilities". Remote Sensing 11, n.º 19 (20 de septiembre de 2019): 2205. http://dx.doi.org/10.3390/rs11192205.

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The three-dimensional registration of industrial facilities has a great importance for maintenance, inspection, and safety tasks and it is a starting point for new improvements and expansions in the industrial facilities context. In this paper, a comparison between the results obtained using a novel portable mobile mapping system (PMMS) and a static terrestrial laser scanner (TLS), widely used for 3D reconstruction in civil and industrial scenarios, is carried out. This comparison is performed in the context of industrial inspection tasks, specifically in the thermal and fluid-mechanics facilities in a hospital. The comparison addresses the general reconstruction of a machine room, focusing on the quantitative and qualitative analysis of different elements (e.g., valves, regulation systems, burner systems and tanks, etc.). The validation of the PMMS is provided considering the TLS as ground truth and applying a robust statistical analysis. Results come to confirm the suitability of the PMMS to perform inspection tasks in industrial facilities.

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37

Perfetti, L. y F. Fassi. "HANDHELD FISHEYE MULTICAMERA SYSTEM: SURVEYING MEANDERING ARCHITECTONIC SPACES IN OPEN-LOOP MODE – ACCURACY ASSESSMENT". International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVI-2/W1-2022 (25 de febrero de 2022): 435–42. http://dx.doi.org/10.5194/isprs-archives-xlvi-2-w1-2022-435-2022.

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Abstract. The task of digitalizing meandering complex spaces in 3D is a challenging one even with the most advanced instrumentation like lightweight terrestrial laser scanner or portable/wearable Mobile Mapping Systems (MMSs). The complexity and extension of architectonic spaces such as staircases, corridors and passages are such that the acquisition time using static devices becomes prohibitive and the accuracy using mobile devices gets affected by drift error leading to warped models or requiring abundant control measurements. This paper presents a photogrammetric portable fisheye multicamera solution for the 3D survey of complex areas that aims at being both handy and fast in the acquisition as well as more reliable ad accurate than common MMSs. The paper showcases a stress test conducted on five complex reconstruction trajectories selected from the meandering connection passages of Milan’s Cathedral. The tests are constructed as worst-case scenario to evaluate the accuracy and drift error amount of the proposed system in open-ended unconstrained paths. The results, though still suffering from moderate drift error, highlights the potential of the solution, especially in retaining the overall shape and orthogonality of the architectonic elements acquired.

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38

NISHIJIMA, Kousuke, Tomohiro TAKAGAWA y Shinji SATO. "Analysis of Coastal Sediment Movement on the basis of high-frequency topography observation by using a portable laser scanner". Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) 67, n.º 2 (2011): I_666—I_670. http://dx.doi.org/10.2208/kaigan.67.i_666.

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39

Allakhverdyan, V. A., A. D. Avrorin, A. V. Avrorin, V. M. Aynutdinov, R. Bannasch, Z. Bardačová, I. A. Belolaptikov et al. "Method and portable bench for tests of the laser optical calibration system components for the Baikal-GVD underwater neutrino Cherenkov telescope". Journal of Instrumentation 16, n.º 12 (1 de diciembre de 2021): C12011. http://dx.doi.org/10.1088/1748-0221/16/12/c12011.

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Abstract The Large-scale deep underwater Cherenkov neutrino telescopes like Baikal-GVD, ANTARES or KM3NeT, require calibration and testing methods of their optical modules. These methods usually include laser-based systems which allow us to check the telescope responses to the light and for real-time monitoring of the optical parameters of water such as absorption and scattering lengths, which show seasonal changes in natural reservoirs of water. We will present a testing method of a laser calibration system and a set of dedicated tools developed for Baikal-GVD, which includes a specially designed and built, compact, portable, and reconfigurable scanning station. This station is adapted to perform fast quality tests of the underwater laser sets just before their deployment in the telescope structure, even on ice, without a darkroom. The testing procedure includes the energy stability test of the laser device, 3D scan of the light emission from the diffuser and attenuation test of the optical elements of the laser calibration system. The test bench consists primarily of an automatic mechanical scanner with a movable Si detector, beam splitter with a reference Si detector and, optionally, Q-switched diode-pumped solid-state laser used for laboratory scans of the diffusers. The presented test bench enables a 3D scan of the light emission from diffusers, which are designed to obtain the isotropic distribution of photons around the point of emission. The results of the measurement can be easily shown on a 3D plot immediately after the test and may be also implemented to a dedicated program simulating photons propagation in water, which allows us to check the quality of the diffuser in the scale of the Baikal-GVD telescope geometry.

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40

Zou, Yiwen, Guangwei Yang, Wanqing Huang, Yang Lu, Yanjun Qiu y Kelvin C. P. Wang. "Study of Pavement Micro- and Macro-Texture Evolution Due to Traffic Polishing Using 3D Areal Parameters". Materials 14, n.º 19 (2 de octubre de 2021): 5769. http://dx.doi.org/10.3390/ma14195769.

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Pavement micro- and macro-texture have significant effects on roadway friction and driving safety. The influence of traffic polish on pavement texture has been investigated in many laboratory studies. This paper conducts field evaluation of pavement micro- and macro-texture under actual traffic polishing using three-dimensional (3D) areal parameters. A portable high-resolution 3D laser scanner measured pavement texture from a field site in 2018, 2019, and 2020. Then, the 3D texture data was decomposed to micro- and macro-texture using Fourier transform and Butterworth filter methods. Twenty 3D areal parameters from five categories, including height, spatial, hybrid, function, and feature parameters, were calculated to characterize pavement micro- and macro-texture. The results demonstrate that the 3D areal parameters provide an alternative to comprehensively characterize the evolution of pavement texture under traffic polish from different aspects.

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41

Qu, Li Gang, Zhi Liang Dong y Hai Jun Zhou. "Large-Scale Complex Aircraft Part Digital Inspection Technology Based on 3D Model". Applied Mechanics and Materials 687-691 (noviembre de 2014): 743–46. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.743.

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This article in view of the present large complex planee parts due to large size,complicated structure, detection method and technical route problem affecting precision and difficult to achieve part, through the use of advanced portable measuring equipment (Metronor light pen measuring instrument, laser scanner and laser tracker device) and product 3D model information to build a reasonable detection technology platform, in view of the different components of the inspection requirements and purposes, using different method to creat the datum, measurement and the assistant tools of different detection technology route, solved the aircraft large, complex parts, assembly process control and quality control in product processing, the difficulty of assembly accuracy control, not only improves the precision of large parts quality and throughout the aircraft parts manufacturing and assembly process reached the assembly efficiency high assembly quality requirements, meet the requirement of aircraft parts assembly process, for large, complex parts of aircraft digital detection technology to lay the solid foundation, further accelerate the process of the development of the current aircraft digital measurement adied assembly technology, improve the efficiency of product processing, lower the manufacturing cost.

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42

Calantropio, A., F. Chiabrando, F. Rinaudo y L. Teppati Losè. "USE AND EVALUATION OF A SHORT RANGE SMALL QUADCOPTER AND A PORTABLE IMAGING LASER FOR BUILT HERITAGE 3D DOCUMENTATION". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-1 (26 de septiembre de 2018): 71–78. http://dx.doi.org/10.5194/isprs-archives-xlii-1-71-2018.

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Abstract. The market of imaging and non-imaging sensors offers nowadays a wide range of products, which are constantly improving and growing. Given the recent advances in the miniaturization of devices for metric survey, and the relatively cheap COTS (Commercial Off The Shelf) solutions widely available, it is therefore crucial to optimally exploit, calibrate and evaluate the performance for 3D data acquisition of the new available devices. These issues are part of the latest research addresses of different Geomatics groups, with the aim to analyze and evaluate these new sensors, in order to discover their real potentialities which are not only connected to their interesting design, low price and small dimensions.According to the final objective of the research, which is the realization of 3D metric survey of a Cultural Heritage site using different techniques and methods, one small UAV (Unmanned Aerial Vehicle) and a portable TLS (Terrestrial Laser Scanner) have been employed. The acquisition strategies and the processing methods are discussed, and the quality of the achievable results is analysed, together with an evaluation of the sensors and the outline of the best practices and use cases scenarios.

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43

Chen, C., B. S. Yang y S. Song. "LOW COST AND EFFICIENT 3D INDOOR MAPPING USING MULTIPLE CONSUMER RGB-D CAMERAS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (2 de junio de 2016): 169–74. http://dx.doi.org/10.5194/isprsarchives-xli-b1-169-2016.

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Driven by the miniaturization, lightweight of positioning and remote sensing sensors as well as the urgent needs for fusing indoor and outdoor maps for next generation navigation, 3D indoor mapping from mobile scanning is a hot research and application topic. The point clouds with auxiliary data such as colour, infrared images derived from 3D indoor mobile mapping suite can be used in a variety of novel applications, including indoor scene visualization, automated floorplan generation, gaming, reverse engineering, navigation, simulation and etc. State-of-the-art 3D indoor mapping systems equipped with multiple laser scanners product accurate point clouds of building interiors containing billions of points. However, these laser scanner based systems are mostly expensive and not portable. Low cost consumer RGB-D Cameras provides an alternative way to solve the core challenge of indoor mapping that is capturing detailed underlying geometry of the building interiors. Nevertheless, RGB-D Cameras have a very limited field of view resulting in low efficiency in the data collecting stage and incomplete dataset that missing major building structures (e.g. ceilings, walls). Endeavour to collect a complete scene without data blanks using single RGB-D Camera is not technic sound because of the large amount of human labour and position parameters need to be solved. To find an efficient and low cost way to solve the 3D indoor mapping, in this paper, we present an indoor mapping suite prototype that is built upon a novel calibration method which calibrates internal parameters and external parameters of multiple RGB-D Cameras. Three Kinect sensors are mounted on a rig with different view direction to form a large field of view. The calibration procedure is three folds: 1, the internal parameters of the colour and infrared camera inside each Kinect are calibrated using a chess board pattern, respectively; 2, the external parameters between the colour and infrared camera inside each Kinect are calibrated using a chess board pattern; 3, the external parameters between every Kinect are firstly calculated using a pre-set calibration field and further refined by an iterative closet point algorithm. Experiments are carried out to validate the proposed method upon RGB-D datasets collected by the indoor mapping suite prototype. The effectiveness and accuracy of the proposed method is evaluated by comparing the point clouds derived from the prototype with ground truth data collected by commercial terrestrial laser scanner at ultra-high density. The overall analysis of the results shows that the proposed method achieves seamless integration of multiple point clouds form different RGB-D cameras collected at 30 frame per second.

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44

Chen, C., B. S. Yang y S. Song. "LOW COST AND EFFICIENT 3D INDOOR MAPPING USING MULTIPLE CONSUMER RGB-D CAMERAS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (2 de junio de 2016): 169–74. http://dx.doi.org/10.5194/isprs-archives-xli-b1-169-2016.

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Driven by the miniaturization, lightweight of positioning and remote sensing sensors as well as the urgent needs for fusing indoor and outdoor maps for next generation navigation, 3D indoor mapping from mobile scanning is a hot research and application topic. The point clouds with auxiliary data such as colour, infrared images derived from 3D indoor mobile mapping suite can be used in a variety of novel applications, including indoor scene visualization, automated floorplan generation, gaming, reverse engineering, navigation, simulation and etc. State-of-the-art 3D indoor mapping systems equipped with multiple laser scanners product accurate point clouds of building interiors containing billions of points. However, these laser scanner based systems are mostly expensive and not portable. Low cost consumer RGB-D Cameras provides an alternative way to solve the core challenge of indoor mapping that is capturing detailed underlying geometry of the building interiors. Nevertheless, RGB-D Cameras have a very limited field of view resulting in low efficiency in the data collecting stage and incomplete dataset that missing major building structures (e.g. ceilings, walls). Endeavour to collect a complete scene without data blanks using single RGB-D Camera is not technic sound because of the large amount of human labour and position parameters need to be solved. To find an efficient and low cost way to solve the 3D indoor mapping, in this paper, we present an indoor mapping suite prototype that is built upon a novel calibration method which calibrates internal parameters and external parameters of multiple RGB-D Cameras. Three Kinect sensors are mounted on a rig with different view direction to form a large field of view. The calibration procedure is three folds: 1, the internal parameters of the colour and infrared camera inside each Kinect are calibrated using a chess board pattern, respectively; 2, the external parameters between the colour and infrared camera inside each Kinect are calibrated using a chess board pattern; 3, the external parameters between every Kinect are firstly calculated using a pre-set calibration field and further refined by an iterative closet point algorithm. Experiments are carried out to validate the proposed method upon RGB-D datasets collected by the indoor mapping suite prototype. The effectiveness and accuracy of the proposed method is evaluated by comparing the point clouds derived from the prototype with ground truth data collected by commercial terrestrial laser scanner at ultra-high density. The overall analysis of the results shows that the proposed method achieves seamless integration of multiple point clouds form different RGB-D cameras collected at 30 frame per second.

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45

Abdul Jabbar, A., I. Aicardi, N. Grasso y M. Piras. "URBAN DATA COLLECTION USING A BIKE MOBILE SYSTEM WITH A FOSS ARCHITECTURE". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W2 (5 de julio de 2017): 3–9. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w2-3-2017.

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European community is working to improve the quality of the life in each European country, in particular to increase the quality air condition and safety in each city. The quality air is daily monitored, using several ground station, which do not consider the variation of the quality during the day, evaluating only the average level. In this case, it could be interesting to have a “smart” system to acquire distributed data in continuous, even involving the citizens. On the other hand, to improve the safety level in urban area along cycle lane, road and pedestrian path, exist a lot of algorithms for visibility and safety analysis; the crucial aspect is the 3D model considered as “input” in these algorithms, which always needs to be updated. A bike has been instrumented with two digital camera as Raspberry PI-cam. Image acquisition has been realized with a dedicated python tool, which has been implemented in the Raspberry PI system. Images have been georeferenced using a u-blox 8T, connected to Raspberry system. GNSS data has been acquired using a specific tool developed in Python, which was based on RTKLIB library. Time synchronization has been obtained with GNSS receiver. Additionally, a portable laser scanner, an air quality system and a small Inertial platform have been installed and connected with the Raspberry system. The system has been implemented and tested to acquire data (image and air quality parameter) in a district in Turin. Also a 3D model of the investigated site has been carried. In this contribute, the assembling of the system is described, in particular the dataset acquired and the results carried out will be described. different low cost sensors, in particular digital camera and laser scanner to collect easily geospatial data in urban area.

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Lu, Qian, Shunxun Li, Jin Zhou, Zhifeng Yao y Wei Li. "The Validity and Reliability of TrueDepth Camera Embedded in the Phone for Foot Measurement". Leather and Footwear Journal 22, n.º 3 (30 de septiembre de 2022): 175–84. http://dx.doi.org/10.24264/lfj.22.3.3.

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There are several laser or structured-light based foot scanners available on the market, which can be used to obtain accurate 3D foot models. Compared to those 3D scanning devices, TrueDepth cameras are portable, inexpensive and easy-to-use. However, the accuracy and reliability of their 3D foot scanning remain to be confirmed. This study aimed to verify the validity and reliability of structured light TrueDepth camera integrated into the mobile phone when it is used for foot measurement. Thirteen students without any kinds of foot abnormalities or foot diseases were recruited and their feet were measured by both Infoot 3D foot scanner and mobile phone with TrueDepth camera. Three parameters were measured including foot length, foot breadth and ball girth. Subsequently, the reliability and validity of the two methods were assessed by linear regression analyses, intraclass Correlation Coefficient and Bland-Altman analysis. The foot breadth and girth circumference measurements all showed high coefficients of determination (R2>0.8) between the two methods and three measurements indicated good to excellent agreements (ICCs>0.9), although the length measurement was reported without significant coefficients of determination. Further, findings from Bland-Altman analysis demonstrated that the measurements from the TrueDepth camera had good agreements with those from Infoot and they could be used interchangeably. However, with the reconstruction algorithm updating in the near future, we could foresee the promotion in foot length measurement when using the TrueDepth camera from the phone. The TrueDepth camera utilizing structured-light and the customized application for foot measurement has fast, accurate and low-cost features and it is a convenient and economical method to obtain the foot 3D model. It can be widely applied for medical purposes and customization.

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47

Pérez-Álvarez, Rubén, Julio Manuel de Luis-Ruiz, Raúl Pereda-García, Gema Fernández-Maroto y Beatriz Malagón-Picón. "3D Documentation with TLS of Caliphal Gate (Ceuta, Spain)". Applied Sciences 10, n.º 15 (4 de agosto de 2020): 5377. http://dx.doi.org/10.3390/app10155377.

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Three-dimensional surveying with a terrestrial laser scanner (TLS) has implied a revolution in the field of 3D modeling, as this methodology provides detailed point-clouds with simplified processes of capture. In addition to the point-clouds, other outputs can be obtained, such as ortho-images, virtual itineraries, 2D cartography, and meshes, which implies a second avenue of multimedia products, such as 3D Portable Document Format (PDF) files and interactive applications. All these options are interesting for the management and broadcast of cultural heritage. The works that have been developed in this research are aimed at setting a workflow for the TLS surveying works and subsequent data management for the generation of a 3D model of the Caliphal Gate of Ceuta, which is considered as one of the most important medieval findings in Spain in recent years, and its immediate surroundings. This model and the different outputs that have been obtained from it allow for the continuation of the historiographic analysis of the complex, while documenting a partial stage in the development of the works of enhancement. In addition to this, these products are not only useful in terms of conservation studies or enhancement, as they are also suitable for the dissemination of the site. Special attention has been set on the paid suitable software for data management while generating the outputs, and for its application by the final users.

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Yeshwanth Kumar, A., M. A. Noufia, K. A. Shahira y A. M. Ramiya. "BUILDING INFORMATION MODELLING OF A MULTI STOREY BUILDING USING TERRESTRIAL LASER SCANNER AND VISUALISATION USING POTREE: AN OPEN SOURCE POINT CLOUD RENDERER". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W17 (29 de noviembre de 2019): 421–26. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w17-421-2019.

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Abstract. With the rapid development in infrastructure, the need to document man-made structures is in increasing demand and inevitable. Such a process of digital documentation of buildings is called Building Information Modelling (BIM). Conventional techniques of BIM involve manual drafting & modelling using computer aided design, drafting & modelling software. Although these techniques are more accurate, given the increase in the size and complexity of modern structures, it would be tedious and time consuming for such manual work. It is in this context LiDAR shows great potential to simplify this task. Laser scanning enables rapid mapping of a building with a high degree of spatial accuracy. Since the spatial point sampling distance of any LiDAR scanner is usually in the order of centimetres or millimetres, this has potential not only to generate high density scans of the building but also to identify even the smallest defects in a structure. This facilitates using LiDAR to study the serviceability of a building. In this project, the feasibility of using a terrestrial laser scanner (TLS) to scan a multi-storey building was investigated. Additionally, the reliability of Potree for visualising point cloud data was tested. Potree is an open-source WebGL based point cloud renderer. Potree enables us to render point clouds and visualise in a portable web application. This application is also capable of making measurements of high accuracy on the 3D model of the library. This could serve to be of great utility in surveying applications. The object of study was chosen as a six-storey building, each floor having differing layouts. Two of these storeys were below ground surface level which also proved to be a test for the reliability of TLS in challenging terrain. The building has a towering height and large footprint which made it a perfect candidate for this project. A total of 54 scans (44 interior scans and 10 exterior scans of the library) were acquired with each subsequent scan station not more than 10m apart from the previous one. This data was brought to the lab for further processing. The processing was carried out using open-source software packages (LAStools, CloudCompare, etc). After processing, the complete point cloud data had 483,292,994 points. In order to make the data easier to handle, spatial sub-sampling of the data was done after which the final point cloud had 87,789,548 points. Finally, this sub-sampled point cloud was published using the open source Potree Converter into an interactive web application.

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Rouzbeh Kargar, Ali, Richard MacKenzie, Gregory P. Asner y Jan van Aardt. "A Density-Based Approach for Leaf Area Index Assessment in a Complex Forest Environment Using a Terrestrial Laser Scanner". Remote Sensing 11, n.º 15 (31 de julio de 2019): 1791. http://dx.doi.org/10.3390/rs11151791.

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Forests are an important part natural ecosystems, by for example providing food, fiber, habitat, and biodiversity, all of which contribute to stable natural systems. Assessing and modeling the structure and characteristics of forests, e.g., Leaf Area Index (LAI), volume, biomass, etc., can lead to a better understanding and management of these resources. In recent years, Terrestrial Laser Scanning (TLS) has been recognized as a tool that addresses many of the limitations of manual and traditional forest data collection methods. In this study, we propose a density-based approach for estimating the LAI in a structurally-complex forest environment, which contains variable and diverse structural attributes, e.g., non-circular stem forms, dense canopy and below-canopy vegetation cover, and a diverse species composition. In addition, 242 TLS scans were collected using a portable low-cost scanner, the Compact Biomass Lidar (CBL), in the Hawaii Volcanoes National Park (HAVO), Hawaii Island, USA. LAI also was measured for 242 plots in the site, using an AccuPAR LP-80 ceptometer. The first step after cleaning the point cloud involved detecting the higher forest canopy in the light detection and ranging (lidar) point clouds, using normal change rate assessment. We then estimated Leaf Area Density (LAD), using a voxel-based approach, and divided the canopy point cloud into five layers in the Z (vertical) direction. These five layers subsequently were divided into voxels in the X direction, where the size of these voxels were obtained based on inter-quartile analysis and the number of points in each voxel. We hypothesized that the intensity returned to the lidar system from woody materials, like branches, would be higher than from leaves, due to the liquid water absorption feature of the leaves and higher reflectance for woody material at the 905 nm laser wavelength. We also differentiated between foliar and woody materials using edge detection in the images from projected point clouds and evaluated the density of these regions to support our hypothesis. Density of points, or the number of points divided by the volume of a grid, in a 3D grid size of 0.1 m, was calculated for each of the voxels. The grid size was determined by investigating the size of the branches in the lower portion of the canopy. Subsequently, we fitted a Kernel Density Estimator (KDE) to these values, with the threshold set based on half of the area under the curve in each of the density distributions. All the grids with a density below the threshold were labeled as leaves, while those grids above the threshold were identified as non-leaves. Finally, we modeled LAI using the point densities derived from the TLS point clouds and the listed analysis steps. This model resulted in an R 2 value of 0.88. We also estimated the LAI directly from lidar data using the point densities and calculating LAD, which is defined as the total one-sided leaf area per unit volume. LAI can be obtained as the sum of the LAD values in all the voxels. The accuracy of LAI estimation was 90%, with an RMSE value of 0.31, and an average overestimation of 9 % in TLS-derived LAI, when compared to field-measured LAI. Algorithm performance mainly was affected by the vegetation density and complexity of the canopy structures. It is worth noting that, since the LAI values cannot be considered spatially independent throughout all the plots in this site, we performed semivariogram analysis on the field-measured LAI data. This analysis showed that the LAI values can be assumed to be independent in plots that are at least 30 m apart. As a result, we divided the data into six subsets in which the plots were 30 m spaced. The R 2 values for these subsets, based on modeling of the field-measured LAI using leaf point density values, ranged between 0.84–0.96. The results bode well for using this method for efficient, automatic, and accurate/precise estimation of LAI values in complex forest environments, using a low-cost, rapid-scan TLS.

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Giordan, Daniele, Danilo Godone, Marco Baldo, Marco Piras, Nives Grasso y Raffaella Zerbetto. "Survey Solutions for 3D Acquisition and Representation of Artificial and Natural Caves". Applied Sciences 11, n.º 14 (14 de julio de 2021): 6482. http://dx.doi.org/10.3390/app11146482.

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A three-dimensional survey of natural caves is often a difficult task due to the roughness of the investigated area and the problems of accessibility. Traditional adopted techniques allow a simplified acquisition of the topography of caves characterized by an oversimplification of the geometry. Nowadays, the advent of LiDAR and Structure from Motion applications eased three-dimensional surveys in different environments. In this paper, we present a comparison between other three-dimensional survey systems, namely a Terrestrial Laser Scanner, a SLAM-based portable instrument, and a commercial photo camera, to test their possible deployment in natural caves survey. We presented a comparative test carried out in a tunnel stretch to calibrate the instrumentation on a benchmark site. The choice of the site is motivated by its regular geometry and easy accessibility. According to the result obtained in the calibration site, we presented a methodology, based on the Structure from Motion approach that resulted in the best compromise among accuracy, feasibility, and cost-effectiveness, that could be adopted for the three-dimensional survey of complex natural caves using a sequence of images and the structure from motion algorithm. The methods consider two different approaches to obtain a low resolution complete three-dimensional model of the cave and ultra-detailed models of most peculiar cave morphological elements. The proposed system was tested in the Gazzano Cave (Piemonte region, Northwestern Italy). The obtained result is a three-dimensional model of the cave at low resolution due to the site’s extension and the remarkable amount of data. Additionally, a peculiar speleothem, i.e., a stalagmite, in the cave was surveyed at high resolution to test the proposed high-resolution approach on a single object. The benchmark and the cave trials allowed a better definition of the instrumentation choice for underground surveys regarding accuracy and feasibility.

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