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Measuring articular cartilage thickness from 3D models developed from laser scans has the potential to offer high accuracy. However, this potential has not been fulfilled, since generating these models requires that the cartilage be removed, and previous methods of removal have led to systematic errors (i.e., bias) due to changes in the overall dimensions of the underlying bone. The objectives were to present a new method for removing articular cartilage, quantify the bias error, and demonstrate the method on the distal (i.e., 0° flexion) and posterior (i.e., 90° flexion) articular surfaces of example human femurs. The method consisted of creating a 3D articular cartilage model from high-accuracy (i.e., precision = 0.087 mm) laser scans before and after cartilage removal using dermestid beetles to remove the cartilage. Fiducial markers were used to minimize errors in registering surfaces generated from the two laser scans. To demonstrate the method, the cartilage thickness was computed in distal and posterior subregions of each femoral condyle for three example cadaveric specimens. The use of dermestid beetles did not introduce measurable bias, and the previously reported precision achieved in 3D cartilage models with the laser scanner was 0.13 mm. For the different subregions, the cartilage thickness ranged from 1.5 mm to 2.0 mm. A method of imaging by means of laser scanning, cartilage removal by means of dermestid beetles, and 3D model registration by means of fiducial markers ensured that cartilage thickness on the articular surface of the long bones of the knee was determined with negligible bias and a precision of 0.13 mm. With this method, the potential to measure cartilage thickness with high accuracy based on 3D models developed from laser scans can be fully realized.

This research paper aims to develop an approach for the digitalization of non-heritage building stock. Existing building stocks in need of rehabilitation are still not subject to optimized, massive digital surveying processes. Thus, it is difficult to assess the performance of the stock in its current state and after potential retrofitting. While massive data capture is being used to model heritage cases with high precision for preservation and documentation projects, this research paper aims to develop an approach for the digitalization of non-heritage building stock that allows for broader implementation, quicker results, and higher scalability, reducing the time required for data capture but still being precise enough for rehabilitation processes. The novel approach combines a laser scanner, thermal infrared sensing, high-quality pictures (HQPs), and automatic frame extraction (AFE) from video. Data preparation for three-dimensional reconstruction is the main novelty of this approach, which has been validated to obtain the surroundings and building information model (BIM) of the reference building for Barcelona schools. The results coincide with previous projects regarding the high precision of a laser scanner and the coverage of photogrammetry. New findings indicate that HQPs are a highly efficient method. Its combination with AFE provides higher levels of coverage. The proposed approach moves forward from the manually modeled BIM misalignments and enables modeling entire clusters to obtain digital twin building stock to ease future management of existing buildings. [ABSTRACT FROM AUTHOR]

In the context of an increasing risk to cultural heritage due to climate change, this review explores and analyzes different geomatics techniques to efficiently monitor and safeguard historical sites and works of art. The rapid succession of technological innovations relating to the production of 3D models and the growth in recent years of the risks to which monumental heritage is exposed poses an all-round reflection on the prospects for the development and refinement of the disciplines of geomatics. The results highlight that geomatics techniques certainly improve data collection and the assessment of risks associated with climate change, also supporting geospatial-based decisions aimed at managing vulnerable cultural sites. The field of digital goods represents, in fact, one of the sectors where it is not possible to centralize knowledge in a single figure, instead postulating a synergistic interaction between different knowledge and techniques. Referring to the national framework, the distinction between protection and enhancement also involves us for both aspects, combining the more consolidated use of digital heritage for cognitive purposes and for the preparation of restoration projects. The study concludes by exploring possible future directions, emphasizing the need for interdisciplinary collaboration and the creation of effective guidelines and policies for the preservation of cultural heritage. Finally, the growing interest in this field in artificial intelligence and, in particular, machine learning is underscored.

Deformation analysis is fundamental in geotechnical modeling. Nevertheless, there is still a lack of an effective method to obtain the deformation field under various experimental conditions. In this study, we introduce a process–based physical modeling of a pile–reinforced reservoir landslide and present an improved deformation analysis involving large strains and water effects. We collect multi–period point clouds using a terrain laser scanner and reconstruct its deformation field through a point cloud processing workflow. The results show that this method can accurately describe the landslide surface deformation at any time and area by both scalar and vector fields. The deformation fields in different profiles of the physical model and different stages of the evolutionary process provide adequate and detailed landslide information. We analyze the large strain upstream of the pile caused by the pile installation and the consequent violent deformation during the evolutionary process. Furthermore, our method effectively overcomes the challenges of identifying targets commonly encountered in geotechnical modeling where water effects are considered and targets are polluted, which facilitates the deformation analysis at the wading area in a reservoir landslide. Eventually, combining subsurface deformation as well as numerical modeling, we comprehensively analyze the kinematics and failure mechanisms of this complicated object involving landslides and pile foundations as well as water effects. This method is of great significance for any geotechnical modeling concerning large-strain analysis and water effects.

In the context of an increasing risk to cultural heritage due to climate change, this review explores and analyzes different geomatics techniques to efficiently monitor and safeguard historical sites and works of art. The rapid succession of technological innovations relating to the production of 3D models and the growth in recent years of the risks to which monumental heritage is exposed poses an all-round reflection on the prospects for the development and refinement of the disciplines of geomatics. The results highlight that geomatics techniques certainly improve data collection and the assessment of risks associated with climate change, also supporting geospatial-based decisions aimed at managing vulnerable cultural sites. The field of digital goods represents, in fact, one of the sectors where it is not possible to centralize knowledge in a single figure, instead postulating a synergistic interaction between different knowledge and techniques. Referring to the national framework, the distinction between protection and enhancement also involves us for both aspects, combining the more consolidated use of digital heritage for cognitive purposes and for the preparation of restoration projects. The study concludes by exploring possible future directions, emphasizing the need for interdisciplinary collaboration and the creation of effective guidelines and policies for the preservation of cultural heritage. Finally, the growing interest in this field in artificial intelligence and, in particular, machine learning is underscored. [ABSTRACT FROM AUTHOR]

The case study of the monumental complex of San Francesco le Moniche, built in the ancient Norman county Aversa, in northern Campania (Italy), is analyzed here. The cultural heritage of the complex and the additional value associated with geoheritage (building stones and underground extraction cavities) have been highlighted. The building stratification of the complex was reconstructed based on documentary sources, including historical cartography and photographic documentation of postcards from the early 1900s. It began around 1200 and ended in the 20th century; part of the original citadel was dismantled and incorporated into the urban fabric in the Fascist era. The building stratification of the complex was also read from the distribution and architecture of the existing underground cavities from which the building stones were extracted. The subsoil, reconstructed on the basis of geological and geophysical data, is made up of a tuff substrate, starting from approximately 5–6 m from the ground level, which represents the main building stone as well as being an important testimony to the long volcanological history of northern Campania. Laser scanner surveys of the known and accessible cavities were carried out to obtain a three-dimensional view of the entire monumental complex and its underground spaces. The results provide a clear example of a geoheritage–cultural heritage interface which reminds us of the importance of an integrated approach in their valorization, specifically in urban areas. Additionally, the results of the study allowed us to improve the knowledge of the complex and the site, and provide useful tools for the planning of future targeted investigations. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiaotong University (Science) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study investigates the impact of different heat transfer approaches on the precision of geometry and solidification behavior in additively manufactured thin clad walls. Employing a 2D laser scanner to assess dimensional accuracy, the study demonstrates that thin clad walls produced on a copper base plate with forced air convection exhibit notably superior accuracy compared to those on a mild steel substrate with natural convection. Microstructure analysis unveils distinct characteristics: Thin clad walls printed with natural convection on mild steel display a coarse columnar dendritic structure marked by increasing primary dendrite arm spacing (PDAS) from bottom to top (10.4 ± 0.7 to 14.5 ± 3 µm). In contrast, forced convection leads to a fine cellular and columnar dendritic microstructure with minor PDAS variation (4.6 ± 0.9 to 7.4 ± 1.7 µm) along the entire vertical span. [ABSTRACT FROM AUTHOR]

Effective forest management and conservation are increasingly critical in addressing the challenges posed by climate change. Advances in remote sensing technologies, such as terrestrial laser scanning, offer promising tools for more accurate assessments in forestry research. This study explores the application of TLS in biomass estimation by conducting a bibliometric analysis of scientific articles indexed in Scopus and the Web of Science. By examining the literature from 2010 to 2024, the study identifies key trends, knowledge gaps, and emerging research opportunities, as well as practical applications in forest management and conservation. The analysis reveals a significant rise in scientific output on TLS, with an average annual growth rate of 8.16%. The most cited works address biomass estimation at the individual tree level using laser scanning data. China and the United States lead in the publication volume with 11 articles. The collaboration network highlights research disparities among regions such as Latin America. Overall, TLS has proven effective for the non-destructive measurement of forest variables and biomass.

Abstract Building information modeling (BIM) can greatly improve the management and planning of historic building conservation projects. However, implementing BIM in the heritage has many challenges, including issues with modeling irregular features, surveying data occlusions, and a lack of predefined libraries of parametric objects. Indeed, surface features can be manually distinguished and segmented depending on the level of human involvement during data scanning and BIM processing. This requires a significant amount of time and resources, as well as the risk of making too subjective decisions. To address these bottlenecks and improve BIM digitization of building geometry, a novel deep learning based scan-to-HBIM workflow is used during the recording of the historic building in historic Jeddah, Saudi Arabia, a UNESCO World Heritage site. The proposed workflow enables access to laser scanner and unmanned aerial vehicle imagery data to create a complete integrated survey using high-resolution imagery acquired independently at the best position and time for proper radiometric information to depict the surface features. By employing deep learning with orthophotos, the method significantly improves the interpretation of spatial weathering forms and façade degradation. Additionally, an HBIM library for Saudi Hijazi architectural elements is created, and the vector data derived from deep learning-based segmentation are accurately mapped onto the HBIM geometry with relevant statistical parameters. The findings give stakeholders an effective tool for identifying the types, nature, and spatial extent of façade degradation to investigate and monitor the structure.

Matching the terrestrial laser scan point clouds with the unmanned aerial oblique photography point clouds of high-rise irregular buildings can make them complementary. The challenge lies in the different sources and qualities, besides arbitrary angular deviations of the two types of point clouds. We propose a registration method based on point and line features, which automatically recognises the features of these point clouds using normal vectors and 3D-Harris, and solves the registration parameters through rigorous adjustment. The registration model, process and method are introduced. Finally, through the analysis of real case examples, it was found that the registration result of this method was better than the traditional Iterative Closest Point (ICP) in the analysed cases, the proposed registration method not only exhibits good automation but also has the ability to ignore various differences in heterogeneous point clouds, thereby improving the accuracy and efficiency of registration for such point clouds. [ABSTRACT FROM AUTHOR]

Effective forest management and conservation are increasingly critical in addressing the challenges posed by climate change. Advances in remote sensing technologies, such as terrestrial laser scanning, offer promising tools for more accurate assessments in forestry research. This study explores the application of TLS in biomass estimation by conducting a bibliometric analysis of scientific articles indexed in Scopus and the Web of Science. By examining the literature from 2010 to 2024, the study identifies key trends, knowledge gaps, and emerging research opportunities, as well as practical applications in forest management and conservation. The analysis reveals a significant rise in scientific output on TLS, with an average annual growth rate of 8.16%. The most cited works address biomass estimation at the individual tree level using laser scanning data. China and the United States lead in the publication volume with 11 articles. The collaboration network highlights research disparities among regions such as Latin America. Overall, TLS has proven effective for the non-destructive measurement of forest variables and biomass. [ABSTRACT FROM AUTHOR]

BIM modeling of existing buildings – a study on effort and efficiency In the project "FHprofUnt 2018: BIM Bauen im Bestand (BIM‐BiB)", funded by the Federal Ministry of Education and Research, the campus of Trier University of Applied Sciences was surveyed using terrestrial laser scanners and the data obtained was transferred to BIM models of the campus buildings. Here, the efficiency of as‐is surveys using 3D scanners, point cloud generation and post‐processing, as well as BIM modeling of existing buildings is examined on the basis of the effort values obtained. The results show that the use of terrestrial laser scanners for as‐is surveys is an efficient method, but the processing and creation of high‐quality point clouds is still very time‐consuming and the actual BIM modeling greatly exceeds the two first‐mentioned work areas in terms of effort. To explain the results presented, the current state of the art and the project‐specific problems are discussed. The data obtained and its evaluation reveal weaknesses in the efficiency of the methods available today and shed light on research opportunities to make the process of modeling existing buildings more economical. [ABSTRACT FROM AUTHOR]

The purpose of this study is to analyze the application of Total Station and Laser Scanner in geodesy surveys to obtain accurate coordinates and evaluate polygon shapes. The Total Station method is used to measure the angle and distance between points, while the Laser Scanner is used to generate point cloud data which is then processed. The data from the two methods were compared to determine the accuracy of the coordinates using the Root-Mean-Square Error (RMSE). The results showed that the Laser Scanner provided higher accuracy than the Total Station, with an RMSE value for horizontal coordinates of 0.038 meters and an elevation of 0.020 meters. Field evaluation also validates the accuracy of the scan results with direct measurements using a hand meter. This study not only confirms the superiority of the Laser Scanner in producing accurate geospatial data, but also supports the development of methodologies and technologies in geodesy surveys. The results of this research make an important contribution to the development of civil engineering science, especially in the context of 3D mapping and its application in infrastructure and construction projects. [ABSTRACT FROM AUTHOR]

In large-scale poultry farming, real-time online measurement of egg weight and shape parameters remains a challenge. To address this, we developed FEgg3D, a non-contact dynamic measuring device based on a self-designed laser scanner. The device employed a subset of the point cloud generated to predict the shape parameters and weight of eggs using machine learning algorithms. Different colors and sizes of eggs on various backgrounds were scanned using FEgg3D mounted on a gantry system. Our results demonstrated the following: (1) The Support Vector Regression (SVR) model was optimal for major axis length estimation, with an R2 of 0.932 using six laser lines and eight points per line. (2) The Gaussian Process Regression (GPR) model excelled in minor axis length estimation, achieving an R2 of 0.974 with six laser lines and 16 points per line. (3) SVR was optimal for volume estimation, attaining an R2 of 0.962 with six laser lines and 16 points per line. (4) GPR showed superior performance in weight prediction, with an R2 of 0.964 using five laser lines and 16 points per line. Including density features significantly improved accuracy to an R2 of 0.978. This approach paves the way for advanced online egg measurement in commercial settings. [ABSTRACT FROM AUTHOR]

Building information modeling (BIM) can greatly improve the management and planning of historic building conservation projects. However, implementing BIM in the heritage has many challenges, including issues with modeling irregular features, surveying data occlusions, and a lack of predefined libraries of parametric objects. Indeed, surface features can be manually distinguished and segmented depending on the level of human involvement during data scanning and BIM processing. This requires a significant amount of time and resources, as well as the risk of making too subjective decisions. To address these bottlenecks and improve BIM digitization of building geometry, a novel deep learning based scan-to-HBIM workflow is used during the recording of the historic building in historic Jeddah, Saudi Arabia, a UNESCO World Heritage site. The proposed workflow enables access to laser scanner and unmanned aerial vehicle imagery data to create a complete integrated survey using high-resolution imagery acquired independently at the best position and time for proper radiometric information to depict the surface features. By employing deep learning with orthophotos, the method significantly improves the interpretation of spatial weathering forms and façade degradation. Additionally, an HBIM library for Saudi Hijazi architectural elements is created, and the vector data derived from deep learning-based segmentation are accurately mapped onto the HBIM geometry with relevant statistical parameters. The findings give stakeholders an effective tool for identifying the types, nature, and spatial extent of façade degradation to investigate and monitor the structure. [ABSTRACT FROM AUTHOR]

This paper presents a novel segmentation algorithm specially developed for applications in 3D point clouds with high variability and noise, particularly suitable for heritage building 3D data. The method can be categorized within the segmentation procedures based on edge detection. In addition, it uses a graph-based topological structure generated from the supervoxelization of the 3D point clouds, which is used to make the closure of the edge points and to define the different segments. The algorithm provides a valuable tool for generating results that can be used in subsequent classification tasks and broader computer applications dealing with 3D point clouds. One of the characteristics of this segmentation method is that it is unsupervised, which makes it particularly advantageous for heritage applications where labelled data is scarce. It is also easily adaptable to different edge point detection and supervoxelization algorithms. Finally, the results show that the 3D data can be segmented into different architectural elements, which is important for further classification or recognition. Extensive testing on real data from historic buildings demonstrated the effectiveness of the method. The results show superior performance compared to three other segmentation methods, both globally and in the segmentation of planar and curved zones of historic buildings. [ABSTRACT FROM AUTHOR]

This paper examines the current and crucial issue of the digitisation of Cultural heritage as it is applied to the archaeological field. It addresses the difficulties of managing and handling big data from archaeological parks that require software, dedicated systems and specific skills, which often result in the transition to digital being perceived as an end in itself. The research focuses on the case study of the archaeological site of Sepino in Molise (Italy) and proposes a workflow for the realisation and subsequent processing of the 3D survey of archaeological parks, recognising that the survey is the first step towards digitalisation. Secondly, it proposes solutions for the consultation, management and valorisation of the surveyed assets, mainly oriented towards dissemination. [ABSTRACT FROM AUTHOR]

When evaluating the shear strength of rock mass discontinuities, certain challenges arise due to the difficulty in quantifying the roughness characteristics of surfaces and the strength of asperities. Recent research has focused on enhancing techniques for assessing these characteristics and exploring the application of laser scanning to aid in evaluating discontinuity features. The analysis of reflectivity values (I) obtained through a laser scanner survey presents an efficient method for assessing mechanical characteristics, such as joint compressive strength (JCS). Reflectivity measurements demonstrate correlations with Schmidt hammer rebound values (r). The laser scanner technique would enable the measurement of JCS without the direct application of the Schmidt hammer on rocks in areas where rebound values (r) measurements are unavailable. The use of a laser scanner allows for the acquisition of high-precision geometrical information concerning the 3D roughness and anisotropy of rock surfaces. In this study, an innovative technique was introduced that utilizes laser scanner data from six previous experimental surveys conducted on rock formations in Southern Italy. This technique facilitates the evaluation of roughness profiles, considering potential variations along kinematically admissible sliding directions, allowing for the estimation of the Joint Roughness Coefficient (JRC). This new methodology aids in evaluating the parameters of Barton's equation to determine the strength characteristics of rock mass discontinuities. [ABSTRACT FROM AUTHOR]

To overcome incomplete point cloud data obtained from laser scanners scanning complex surfaces, multi-viewpoint cloud data needs to be aligned for use. A hybrid improved SAC-IA with a KD-ICP algorithm is proposed for local point cloud alignment optimization. The scanned point cloud data is preprocessed with statistical filtering, as well as uniform down-sampling. The sampling consistency initial alignment (SAC-IA) algorithm is improved by introducing a dissimilarity vector for point cloud initial alignment. In addition, the iterative closest point (ICP) algorithm is improved by incorporating bidirectional KD-tree to form the KD-ICP algorithm for fine point cloud alignment. Finally, the algorithms are compared in terms of runtime and alignment accuracy. The implementation of the algorithms is based on the Visual Studio 2013 software configurating point cloud library environment for testing experiments and practical experiments. The overall alignment method can be 40%~50% faster in terms of running speed. The improved SAC-IA algorithm provides better transformed poses, combined with the KD-ICP algorithm to select the corresponding nearest neighbor pairs, which improves the accuracy, as well as the applicability of the alignment. [ABSTRACT FROM AUTHOR]

TLS has intriguing experimental procedures to investigate how various scanned surface reflectivity and roughness affected the accuracy of the scanned TLS data at various incident angles and ranges. Thus, different materials (glass, steel, wood, Ekoplast, and the sheet target of the total station) were used. During the experiment, four distinct ranges (5 m, 20 m, 40 m, and 60 m) under the same weather conditions were employed. The selected materials were scanned at 6 incident angles from 0˚ to 75˚, rotating 15˚ per scan. This means a total of 96 scans were measured. At various scan angles and ranges, smooth surfaces have a greater effect on the quality of the scanned data than rough surfaces. The whole Total Station (TS) target reflects approximately 200mm closer to the instrument at 0˚ incident angle than the other materials at the 5m range; this difference decreases as the incident angle increases. On the other hand, this difference also decreases with increasing the range; at 0˚ and 5m range, it’s about 200mm, while for the same angle and 60m range, it's about 120mm. Furthermore, the density of the point clouds decreases with increasing range. Finally, the effect of the distance clearly appeared on the small incident angle rather than the large incident angle.

Abstract Heritage buildings represent history and act as vessels of human civilisation. The significance of these architectural phenomena increases as society increases, which renders their preservation and ethical use increasingly crucial. Hence, preserving heritage buildings is necessary for societal benefit. The accuracy of three-dimensional (3D) point cloud models of heritage buildings is important to their digital conservation. Traditional mapping methods typically require more time and human resources. Furthermore, the outcome is subject to measurement omissions, errors, and other issues, which are contrary to the protection of the object measured. The complex elements of ancient Chinese architecture render it challenging for traditional measuring techniques to accurately capture spatial structural information. The 3D laser scanning technology is a novel technology to obtain 3D data rapidly. In this paper, the Great Achievement Palace of the Confucian Temple in Yuci District, Jinzhong City, Shanxi Province, was used as an example to examine the application of 3D laser scanning technology to acquire point cloud models of heritage buildings. Field data collection for architectural heritage using 3D laser scanning technology requires measuring station setting analysis to ensure effect accuracy while considering the elements of target location and quantity. For the 3D point cloud model of the Great Achievement Palace, error analysis and accuracy assessment were conducted on the quality elements of alignment accuracy between scanning stations, point cloud model reliability, point cloud data noise condition, and whether the point cloud data were stratified. The findings demonstrated that the improved method quickly and accurately acquired 3D point cloud model data and obtained realistic spatial data models of the heritage building.

The dimensional accuracy of a laser scanner has been extensively evaluated using various measurement methods and diverse reference standards. This study specifically focuses on two key considerations. Firstly, it assesses the dimensional accuracy of the laser scanner by employing another laser scanner, a handheld scanner, as the reference measurement method. Secondly, the study involves the use of three spheres fixed on each wall in both coplanar and non-coplanar positions within a laboratory room at SENAI ISI-SIM. The primary objective is to determine the dimensional accuracy between the centers of the coplanar and non-coplanar spheres up to 10 m. The comparison includes measurement uncertainties, as per ISO GUM standards, obtained using the laser scanner in a laboratory setting with controlled temperature and humidity. Analyzing non-coplanar dimensional accuracy enhances our understanding of the metrological performance of the laser scanner, particularly when assessing the dimensions of objects positioned randomly within a scanning scene.

This research paper aims to develop an approach for the digitalization of non-heritage building stock. Existing building stocks in need of rehabilitation are still not subject to optimized, massive digital surveying processes. Thus, it is difficult to assess the performance of the stock in its current state and after potential retrofitting. While massive data capture is being used to model heritage cases with high precision for preservation and documentation projects, this research paper aims to develop an approach for the digitalization of non-heritage building stock that allows for broader implementation, quicker results, and higher scalability, reducing the time required for data capture but still being precise enough for rehabilitation processes. The novel approach combines a laser scanner, thermal infrared sensing, high-quality pictures (HQPs), and automatic frame extraction (AFE) from video. Data preparation for three-dimensional reconstruction is the main novelty of this approach, which has been validated to obtain the surroundings and building information model (BIM) of the reference building for Barcelona schools. The results coincide with previous projects regarding the high precision of a laser scanner and the coverage of photogrammetry. New findings indicate that HQPs are a highly efficient method. Its combination with AFE provides higher levels of coverage. The proposed approach moves forward from the manually modeled BIM misalignments and enables modeling entire clusters to obtain digital twin building stock to ease future management of existing buildings.

In this study, point cloud data were obtained from an underground limestone mine using a laser scanner. A numerical analysis was performed using discontinuous and continuous models, and the stability of two pillars located in large underground openings was analyzed. The safety factor was 1.0 or higher in both analyses, and the displacement was insignificant compared to the pillar size, confirming the pillar stability. Additionally, the safety factor of the discontinuous model was reduced by approximately 30% compared to that of the continuous model, and the displacement was increased by approximately 40%. The change in the safety factor was examined by applying the minimum, average and maximum mechanical properties of the investigated rock mass. The analysis determined that an average change of 50% occurred in the safety factor when the minimum and maximum mechanical properties of the rock mass were compared. [ABSTRACT FROM AUTHOR]

The dimensional accuracy of a laser scanner has been extensively evaluated using various measurement methods and diverse reference standards. This study specifically focuses on two key considerations. Firstly, it assesses the dimensional accuracy of the laser scanner by employing another laser scanner, a handheld scanner, as the reference measurement method. Secondly, the study involves the use of three spheres fixed on each wall in both coplanar and non-coplanar positions within a laboratory room at SENAI ISI-SIM. The primary objective is to determine the dimensional accuracy between the centers of the coplanar and non-coplanar spheres up to 10 m. The comparison includes measurement uncertainties, as per ISO GUM standards, obtained using the laser scanner in a laboratory setting with controlled temperature and humidity. Analyzing non-coplanar dimensional accuracy enhances our understanding of the metrological performance of the laser scanner, particularly when assessing the dimensions of objects positioned randomly within a scanning scene. [ABSTRACT FROM AUTHOR]

(1) The early assessment of wood quality, even while trees are standing, provides significant benefits for forest management, sales efficiency, and market diversification. Its definition cannot be in absolute terms but must always be linked to the material's intended use. (2) In this contribution, a review of the scientific literature is given to discuss the visually evaluable attributes that define wood quality in standing trees, the applicability of the techniques used for their assessment, and the effectiveness of these attributes and technologies in predicting quality, to finally highlight future research needs. (3) The visual characteristics generally used to evaluate wood quality are linked to stem form and dimension, branchiness, and stem damage, but their assessment is challenging due to time and resource constraints. To address these challenges, laser-based and image-based techniques have been applied in field surveys. (4) Laser scanners offer detailed and accurate measurements. Photogrammetry, utilizing images to reconstruct 3D models, provides a cost-effective and user-friendly alternative. Studies have demonstrated the effectiveness of these tools in surveying the visible properties of stems and branches, but further development is necessary for widespread application, particularly in software development, with faster and more effective algorithmic advancements for automatic recognition and subsequent measurement of pertinent characteristics being critical for enhancing tool usability. (5) However, predicting wood quality from these surveys remains challenging, with a limited correlation between the visible tree characteristics assessed and the sawn product quality. Empirical studies evaluating products downstream in the forest-wood supply chain could provide valuable insights. In this sense, the implementation of traceability systems could facilitate the linkage between data on standing trees and the quality of the sawn product. Also, further research is needed to develop models that can accurately predict internal tree characteristics and their impact on product quality. [ABSTRACT FROM AUTHOR]

Copyright of Turkey Lidar Journal / Türkiye Lidar Dergisi is the property of Mersin University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heritage buildings represent history and act as vessels of human civilisation. The significance of these architectural phenomena increases as society increases, which renders their preservation and ethical use increasingly crucial. Hence, preserving heritage buildings is necessary for societal benefit. The accuracy of three-dimensional (3D) point cloud models of heritage buildings is important to their digital conservation. Traditional mapping methods typically require more time and human resources. Furthermore, the outcome is subject to measurement omissions, errors, and other issues, which are contrary to the protection of the object measured. The complex elements of ancient Chinese architecture render it challenging for traditional measuring techniques to accurately capture spatial structural information. The 3D laser scanning technology is a novel technology to obtain 3D data rapidly. In this paper, the Great Achievement Palace of the Confucian Temple in Yuci District, Jinzhong City, Shanxi Province, was used as an example to examine the application of 3D laser scanning technology to acquire point cloud models of heritage buildings. Field data collection for architectural heritage using 3D laser scanning technology requires measuring station setting analysis to ensure effect accuracy while considering the elements of target location and quantity. For the 3D point cloud model of the Great Achievement Palace, error analysis and accuracy assessment were conducted on the quality elements of alignment accuracy between scanning stations, point cloud model reliability, point cloud data noise condition, and whether the point cloud data were stratified. The findings demonstrated that the improved method quickly and accurately acquired 3D point cloud model data and obtained realistic spatial data models of the heritage building. [ABSTRACT FROM AUTHOR]

Recently, robots for medical services are attracting attention as medical technology advances and interest in health increases. In particular, social robot technology plays an important role in interacting with subjects and providing health information using IoT sensors, and among these, gait information monitoring is used as an crucial tool in the medical field. There are several methods for monitoring gait information, but in this paper, a 2D laser scanner mounted on a robot was used to analyze the gait of a monitored subject, and the face-to-face posture control of the robot had a significant impact on gait pattern recognition, especially when walking at a certain distance. The results showed that it showed higher accuracy than wearable devices in the above walking situations. Accordingly, the possibility of providing medical information, such as analysis of the subject's gait, was confirmed as the service robot interacts with a walking human through face-to-face posture control. [ABSTRACT FROM AUTHOR]

In mobile robotics, LASER scanners have a wide spectrum of indoor and outdoor applications, both in structured and unstructured environments, due to their accuracy and precision. Most works that use this sensor have their own data representation and their own case-specific modeling strategies, and no common formalism is adopted. To address this issue, this manuscript presents an analytical approach for the identification and localization of objects using 2D LiDARs. Our main contribution lies in formally defining LASER sensor measurements and their representation, the identification of objects, their main properties, and their location in a scene. We validate our proposal with experiments in generic semi-structured environments common in autonomous navigation, and we demonstrate its feasibility in multiple object detection and identification, strictly following its analytical representation. Finally, our proposal further encourages and facilitates the design, modeling, and implementation of other applications that use LASER scanners as a distance sensor. [ABSTRACT FROM AUTHOR]

Constructing cruise-ship hull is long, complex and requires relatively precise metal carpentry, welding and assembly operations. Timely detection and correction of anomalies is vital to the sustainability of the process, in terms of reducing production time and costs. This paper presents a novel statistical quality control (SQC) methodology for monitoring the workshop for the production of so-called "modules" within shipyards, i.e., roughly parallelepiped sub-assemblies of large dimensions (on the order of several tens of meters on each side), obtained through manual carpentry and welding operations. The proposed methodology adopts a standardized p control chart with samples of variable size, incorporating two elements: (i) it accounts for the high level of customization of modules, and (ii) it takes into consideration the measurement uncertainty associated with the large-volume metrology instrument employed for conformity verification (such as a state-of-the-art Leica RTC360 laser scanner), following the ISO 14253-1:2017 standard. A real-world case study at an Italian Fincantieri S.p.A. shipyard demonstrates its practical application. [ABSTRACT FROM AUTHOR]

The architectural graphic expression, with all the variants that make it up, strengthens a substantial part of the process of approaching the project, also of its resolution. When the architectural intervention corresponds to the rehabilitation of a historic building, the aforementioned link acquires greater prominence, both in the previous phases of analysis, and in the consequent decisions that will derive from them. The help of technologies in the capture of information and the possibilities of virtualization provided by computer applications, have determined both the work methodologies and the forms of graphic representation to obtain results.This article describes the processes carried out for the graphic representation of a Renaissance palace in the province of Teruel, Casa Castellote, as a starting point to advance in its knowledge.Every graphic survey, any virtual model analyzing an architectural object, the intangible contribution of the initial sketches, and the conclusive planimetric representation configure an essential scientific research to address a project solution.This analytical graphic process, as well as the consequent creative graphic process, require systematization. The result is the obtaining of a digital model that will allow the study and analysis of the model through different visualizations, whether planimetry, or virtual three-dimensional models, which, in addition, enable accessibility to the documentation of the heritage asset and its dissemination to society.DOI: https://doi.org/10.20365/disegnarecon.30.2023.9

The research deals with the topic of archaeological surveys through the use of laser scanners and drones and the integration of appropriate data processing methodologies, aimed at promoting processes of documentation, knowledge, restoration and enhancement of the archaeological heritage.The object of the investigation is the Mausoleum of Sant’Urbano at the 4th mile of the Via Appia Antica, dating back to the 4th century AD, annexed to the Appia Antica Archaeological Park in 2021. Prior to 2021 it was privately owned and had undergone disfigurements and alterations of the original masonry.The research presented derives from a scientific collaboration agreement between the Appia Antica Archaeological Park, the Department of Architecture at Roma Tre University, the Department of Humanities, Philosophical Studies, and History of Art at Tor Vergata University, aimed at study, survey and monumental analysis of the mausoleum.The presented research resulted in the definition of a survey methodology of the archaeological heritage in which the data acquisitions from the aerial photogrammetric method and from the instrumental method are integrated aimed at the documentation, knowledge and dimensional and morphological restitution of an asset of significant historical and identity interest. The first results have made it possible to obtain a graphic restitution, numerical models or orthophotos on the basis of which the archaeological and historical multidisciplinary studies, the restoration and conservation interventions and the enhancement and use strategies by the Appia Antica Archaeological Park will be conducted.DOI: https://doi.org/10.20365/disegnarecon.30.2023.4

The castle of Ademuz constitutes a relevant heritage value of this spanish town and of the Rincón de Ademuz municipal district and is a key element to understand the configuration of the village and its importance as a defensive town throughout history. However, the lack of documents about the castle and its lamentable condition make it a largely unknown monument. Actions are currently implemented to reverse this alarming situation and the drafting of the Master Plan of the Castle of Ademuz has been the first step to raise awareness about its recovery and enhancement. The Master Plan has summarized the existing documentary information about the castle and its legal and urban situation as a step prior to its constructive and formal analysis. The graphic survey carried out in the drafting of the Master Plan constitutes an unpublished knowledge contribution on this property, which has allowed us to establish hypotheses about its compositional traces and to guide the lines of action for its recovery.This unprecedented graphic survey will also allow defining each of the lines of action of the Master Plan, from the structural consolidation of the remains of the castle to the conditioning of the spaces that surround it, as well as its cultural dissemination through the new digital technologies linked to virtual reality and augmented reality, among others. The objective is to enhance this architectural heritage through its knowledge and dissemination, so that this legacy is preserved for future generations.DOI: https://doi.org/10.20365/disegnarecon.30.2023.26

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Knowledge of fracture properties and associated flow processes is important for geoscience applications such as nuclear waste disposal, geothermal energy and hydrocarbons. An important tool established in recent years are hydro-mechanical models which provide a useful alternative to experimental methods determining single fracture parameters such as hydraulic aperture. A crucial issue for meaningful numerical modeling is precise imaging of the fracture surfaces to capture geometrical information. Hence, we apply and compare three distinct fracture surface imaging methods: (1) handheld laser scanner (HLS), (2) mounted laser scanner (MLS) and (3) Structure from Motion (SfM) to a bedding plane fracture of sandstone. The imaging reveals that the resolution of the fracture surface obtained from handheld laser scanner (HLS) is insufficient for any numerical simulations, which was therefore rejected. The remaining surfaces are subsequently matched and the resulting fracture dataset is used for detailed fracture flow simulations. The resulting hydraulic aperture is calibrated with laboratory measurements using a handheld air permeameter. The air permeameter data provide a hydraulic aperture of 81 ± 1 µm. For calibration, mechanical aperture fields are calculated using stepwise increasing contact areas up to 15%. At 5% contact area, the average hydraulic aperture obtained by MLS (85 µm) is close to the measurement. For SfM, the measurements are fitted at 7% contact area (83 µm). The flow simulations reveal preferential flow through major channels that are structurally and geometrically predefined. Thus, this study illustrates that resolution and accuracy of the imaging device strongly affect the quality of fluid flow simulations and that SfM provides a promising low-cost method for fracture imaging on cores or even outcrops. Highlights: We evaluate a handheld laser scanner, a mounted laser scanner and the Structure from Motion method for imaging of fracture surfaces. We use the scanned geometries for flow simulations and calibrate the results with air permeameter measurements. Our study reveals that the handheld laser scanner is unsuitable for fracture surface imaging due to low resolution and accuracy. The simulations performed with geometries obtained by the mounted laser scanner and the Structure from Motion method provided comparable results. The Structure from Motion method seems to be promising for fracture investigations in field applications due to the high flexibility and low costs. [ABSTRACT FROM AUTHOR]

Rapid, precise and frugal surveying is a strategic factor in the present mechanized mining environment owing to rapid surface profile transformation in a short period. Determination of global coordinates with high accuracy using the satellite-based global navigation satellite system (GNSS) has been studied in the mining arena and is gradually becoming an essential component. A case study of Khanak Stone Mine, Haryana, India, is discussed here, highlighting the combination of GNSS system and terrestrial laser scanner for the preparation of a surface profile of a rugged terrain with the key objective to determine the precise in situ rock excavation in periodical phases. The actual tonnage of rock produced/transported from the mine has been calculated by determining the in situ density and bulk density in the laboratory. The study reveals that this survey of approach is apt to achieve quality plan and to obtain the goal of actual tonnage of rocks excavated. [ABSTRACT FROM AUTHOR]

The rapid advancement of mobile laser scanner technology used for terrain mapping, among other things, imposes increasing requirements for scanning frequency and distance measurement accuracy. To meet these requirements, rangefinder modules are expected to operate with high echo signal dynamics and to allow accurate distance measurement even based on single-laser-pulse echo detection. Such performance can be potentially achieved using pulsed time-of-flight (ToF) laser rangefinders (LRF). In conventional ToF modules, however, the STOP signal (for time counter interruption) is generated using a straightforward fixed-threshold comparator method. Unfortunately, it corresponds to the so-called walk error, i.e., the dependence of the measured time of flight on the magnitude of the echo signal. In most ranging applications, however, the LRF detection channel can be exposed to an extremely large span of received echo power levels, which depend on the distance measured, type of target surface, atmospheric transmission, etc. Thus, the walk error is an inseparable element of the conventional ToF technique and creates a fundamental limit for its precision. This article presents a novel method of walk error compensation in real time. By using our authorial electronic circuit for measuring the magnitude of the echo signal, it is possible to effectively compensate for the walk error even when the echo signal brings the detection channel amplifiers into saturation. In addition, the paper presents a laboratory method for calibrating the walk error compensation curve. [ABSTRACT FROM AUTHOR]