- 标题
- 摘要
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- 实验方案
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Integration of Terrestrial Laser Scanning and UAS Photogrammetry in Geological Studies: Examples from Croatia
摘要： Terrestrial laser scanning (TLS) in combination with Unmanned Aircraft System (UAS) and modern computer based photogrammetry is currently the best approach for the acquisition of high-resolution 3D spatial information. Highly realistic 3D spatial data sets are becoming the basis for detailed geological studies, providing a multidisciplinary approach in the study and research of both underground and above ground sites. To emphasize the variety of possible implementations of these state-of-the-art methodologies, four characteristic and yet quite different case studies are presented where such geodetic techniques are successfully employed. The presented case studies demonstrate that TLS and UAS photogrammetry, as non-contact surveying methods, are able to reduce survey time and total project costs. As added value, they provide high-resolution data that can be analyzed in a virtual environment from a sedimentological or structural aspect. Stored digital documentation also allows future multi-temporal spatial data comparison at any timeframe and scale, thus enhancing any target geological data gathering and analyses at the studied sites.
关键词： 3D virtual model building,Terrestrial Laser Scanning (TLS),virtual outcrop,Unmanned Aircraft System (UAS),photogrammetry
更新于2025-09-16 10:30:52
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Investigation of the effects of nonstationary features on rock joint roughness using the laser scanning technique
摘要： Accurately estimating rock joint roughness is crucial for understanding the shear mechanism and permeability behavior of a rock mass. Several influencing factors, including anisotropy, measurement noise, and the scale effect and sampling interval, have been considered. However, little attention is paid to the influences of nonstationary features on the roughness assessment. In this study, a portable laser scanner was employed to collect high-density 3D point clouds of ten natural rock joint specimens. Based on two parameters, namely, the bright area percentage (BAP) and θ*max/(C + 1), where θ*max is the maximum apparent dip angle and C is a dimensionless fitting parameter, the rock joint roughness was determined before and after removing nonstationary features, and a comparison showed that nonstationary features have a considerable influence on the roughness. Subsequently, an approach was proposed to remove nonstationary features through the conversion of spatial coordinates, and an application to a roughness evaluation illustrated that similar trends are observed between the BAP and θ*max/(C + 1) with respect to the point clouds of ten rock joints whose nonstationary features were removed. These findings reveal that nonstationary features should be removed to improve the accuracy and comparability of the roughness assessments.
关键词： 3D laser scanning,Rock joint,Roughness estimation,Nonstationary features
更新于2025-09-16 10:30:52
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Automatic road-marking detection and measurement from laser-scanning 3D profile data
摘要： Automatic road-marking detection and measurement have great significance for pavement maintenance and management. Laser-scanning 3D profile data provide a new way of road-marking detection and measurement with an elevation accuracy of about 0.25 mm. This paper presents an automatic road-marking detection and measurement method that uses laser scanning of 3D pavement data. The elevation characteristics and geometric statistics that characterize road markings have been fully analyzed using 3D data. The first step was to use a specially designed step-shaped operator to convolve profile data to identify the regions of suspected marking edges at the profile level, which helps reduce the influence of other pavement factors, including crosswise-slope information, cracks, and rutting. Next, by combining the geometric characteristics of the road-marking region and the continuity of the convolution features at image level, the regions of suspected 3D road markings were extracted. Third, a convolutional neural network was introduced to distinguish real-marking data more clearly. Finally, the three-dimension measurement information was extracted from the detected region and from elevation information. Road-marking recognition experiments were then conducted based on real measured 3D data. The detection accuracies were all greater than 90.8% for 4178 test samples from five road sections with different kinds of road markings. Furthermore, the repeatability of multiple measurement results for road-marking elevations from two selected road sections was about 95%, and the correlation of the obtained road-marking elevations with manually measured elevations was about 85.36% for 200 measurement points.
关键词： Road-marking detection,Laser scanning,Convolution,Three-dimension measurement information,Convolutional neural network
更新于2025-09-16 10:30:52
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The generation and validation of a CUF-based FEA model with laser-based experiments
摘要： Architectural structures today are increasingly complex and structural health monitoring plays an important role in guaranteeing their safety. How to improve the reliability of deformation analysis is, thus, one of the key problems. This article combines laser-based measurement technology and the Carrera unified formulation (CUF) method to investigate the deformation of engineering structures. Within this article, we simulate architectural structures using the CUF geometric model, which is consistent with the results of the laser tracker experiment. We aimed at constructing an intelligent and efficient CUF model which can be applied extensively in the monitoring of various constructs, such as tunnels and bridges. The innovation of this article is that high-accuracy laser tracker technology is integrated with an effective CUF model to investigate the load-displacement relationship considering lateral displacement.
关键词： multi-sensor,laser tracker,SHM,FEA,terrestrial laser scanning
更新于2025-09-12 10:27:22
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[IEEE 2018 Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA) - Poznan (2018.9.19-2018.9.21)] 2018 Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA) - Programmatic Simulation of Laser Scanning Products
摘要： The technology of laser scanning is widely used for producing three-dimensional digital representations of geographic features. The measurement results are usually available in the form of 3D point clouds, which are often used as a transitional data model in various remote sensing applications. Unfortunately, while the costs of Light Detection And Ranging scanners have dropped significantly in recent years, they are still considered to be quite expensive for smaller institutions. In consequence, the process of 3D point cloud acquisition remains a difficult one, requiring investment not only in scanning equipment, but also time to operate it and process the obtained results. However, if the goal does not involve the 3D digitalization of a particular object, but instead the point clouds are required e.g. for testing reconstruction algorithms, in many cases such input data can be successfully substituted with the results of a simulated scanning process, which is far easier to accomplish. This paper presents a programmatic simulator which generates artificial scanning results from solid meshes provided by the user and saves them in the form of point cloud datasets.
关键词： 3D,Laser scanning,Point cloud,Simulation,LiDAR
更新于2025-09-12 10:27:22
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Relief-Frequency Characteristics of Laser Scanners
摘要： The concept of the relief-frequency characteristic of laser scanners is introduced. The necessity of using the relief-frequency characteristic is substantiated with a description of the frequency properties of laser scanners. A procedure for experimental determination of the relief-frequency characteristic of laser scanners has been developed, and studies were carried out. It is shown that the relief-frequency characteristic makes it possible to estimate most precisely the error of the laser scanner and to determine the range of reproduced spatial frequencies when scanning a relief. The proposed procedure can be used to describe the metrological characteristic of laser scanners.
关键词： sampling,laser scanning,relief-frequency characteristic,measurement error,spatial-frequency characteristic,convolution
更新于2025-09-12 10:27:22
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3-D Laser Scanning Landslide Deformation Monitoring and Data Processing Based on Computer Cluster
摘要： Landslide monitoring is an important technical means for monitoring and forecasting landslides. At present, three-dimensional laser scanning technology has been applied to deformation monitoring, such as landslide monitoring. The three-dimensional laser scanning technology can measure the three-dimensional coordinates of the object surface with high precision, high density and high speed, thus describing the details of the surface in detail. It has been successfully applied in static shape measurement. Computer cluster is widely used in various computationally intensive tasks because of its high cost performance and good scalability. Combined with the deformation information of deformation monitoring points, the deformation trend of landslide body is effectively monitored and predicted. In order to process the obtained data in a timely and rapid manner, the computer cluster performs the absolute orientation of the sequence point cloud collected in different periods to complete the coordinate system, and then acquires a set of points of different periods of point cloud data at the same position of the computer cluster. The data was compared and analyzed. In addition, the acquisition of ground-type 3D laser scanner data does not require the deployment of monitoring points, which can reflect the surface morphology of the landslide more quickly and accurately than the traditional monitoring means, and then obtain the surface deformation value.
关键词： 3-D Laser Scanning,Data Processing,Computer Cluster,Landslide Deformation Monitoring
更新于2025-09-12 10:27:22
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Antimicrobial effectiveness of grape seed extract against <i>Enterococcus faecalis</i> biofilm: A Confocal Laser Scanning Microscopy analysis
摘要： This study evaluated the antimicrobial effectiveness of 6.5% Vitis vinifera grape seed extract (GSE) against Enterococcus faecalis bio?lm using confocal laser scanning microscopy (CLSM). Saline solution (SS), 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) were used for comparison. Dentin discs were inoculated with E. faecalis strain establishing a 3-week-old bio?lm. Discs (n = 10) were exposed to 5.25% NaOCl, 2% CHX, 6.5% GSE and SS (negative control) for 10 min. Discs were stained with the ?uorescent LIVE/DEAD-BacLightTM dye and analysed using CLSM. The proportion of dead cells in bio?lm was analysed using one-way ANOVA and Tukey tests (P < 0.05). A higher proportion of dead cells was found in GSE group compared with CHX and SS (P < 0.05). NaOCl group was associated with the highest proportion of dead cells (P < 0.05). GSE presented antimicrobial activity against E. faecalis; however, NaOCl was the most effective irrigant solution. GSE was more effective than CHX and SS.
关键词： bio?lm,root canal irrigants,grape seed extract,confocal laser scanning microscopy,Enterococcus faecalis
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Auckland, New Zealand (2019.5.20-2019.5.23)] 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Scanning Double-Beam Laser Interferometer with Loop-Back Compensation and Phase Stabilization
摘要： An accurate characterization of piezoelectric films is essential for their usage in various types of MEMS sensors and actuators. This paper presents a novel scanning double-beam laser interferometer (DBLI) to measure the thickness piezoelectric coefficient with a high accuracy. Compared to previous DBLI solutions, we employ a closed-loop phase shift compensation via an electro-optical modulator to stabilize the random phase drift as well as to compensate the harmonic sample-induced phase shift. As a consequence, the setup robustness is enhanced and the measured displacement is no more sensitive to sample reflectivity or source and detector signal gains, which allows to use the DBLI as scanning.
关键词： double-beam,laser scanning interferometry,phase compensation
更新于2025-09-12 10:27:22
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Enhanced transmitting and blocking filter design approach for laser scanning applications based on combining GSM and AFGSM methods
摘要： We present a novel and robust filter design method, developed for one-dimensional photonic crystal-based filters. Hybrid filter structures are presented comprising periodic and degenerated multilayered dielectric structures. The proposed approach provides significant flexibility in designing desired transmission band while offering widened stop-bands. In obtaining the transmission characteristics we utilize the Auxiliary Functions of Generalized Scattering Matrix Method (AFGSM), already proven to provide computational advantages in obtaining bandgap edge frequencies without solving an eigenvalue equation. With the proposed design strategy, we showcase its efficacy through designing four different filters that are utilized in laser scanning microscopy; namely a laser line filter at 800 nm wavelength for reflectance confocal microscopy, a band-pass filter at 400 nm wavelength for second harmonic generation microscopy, a laser block filter at 800 nm wavelength and a dichroic filter blocking 350-400 nm while transmitting higher wavelengths for multiphoton microscopy.
关键词： Multilayered Dielectrics,Optical Filters,Fabry-Perot Resonators,Auxiliary Functions of Generalized Scattering Matrix (AFGSM),Photonic Bandgaps (PBGs),Laser Scanning Microscopy (LSM)
更新于2025-09-12 10:27:22