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Sample records for 3d laser scanner

  1. 3D ultrafast laser scanner

    NASA Astrophysics Data System (ADS)

    Mahjoubfar, A.; Goda, K.; Wang, C.; Fard, A.; Adam, J.; Gossett, D. R.; Ayazi, A.; Sollier, E.; Malik, O.; Chen, E.; Liu, Y.; Brown, R.; Sarkhosh, N.; Di Carlo, D.; Jalali, B.

    2013-03-01

    Laser scanners are essential for scientific research, manufacturing, defense, and medical practice. Unfortunately, often times the speed of conventional laser scanners (e.g., galvanometric mirrors and acousto-optic deflectors) falls short for many applications, resulting in motion blur and failure to capture fast transient information. Here, we present a novel type of laser scanner that offers roughly three orders of magnitude higher scan rates than conventional methods. Our laser scanner, which we refer to as the hybrid dispersion laser scanner, performs inertia-free laser scanning by dispersing a train of broadband pulses both temporally and spatially. More specifically, each broadband pulse is temporally processed by time stretch dispersive Fourier transform and further dispersed into space by one or more diffractive elements such as prisms and gratings. As a proof-of-principle demonstration, we perform 1D line scans at a record high scan rate of 91 MHz and 2D raster scans and 3D volumetric scans at an unprecedented scan rate of 105 kHz. The method holds promise for a broad range of scientific, industrial, and biomedical applications. To show the utility of our method, we demonstrate imaging, nanometer-resolved surface vibrometry, and high-precision flow cytometry with real-time throughput that conventional laser scanners cannot offer due to their low scan rates.

  2. Optical monitoring of scoliosis by 3D medical laser scanner

    NASA Astrophysics Data System (ADS)

    Rodríguez-Quiñonez, Julio C.; Sergiyenko, Oleg Yu.; Preciado, Luis C. Basaca; Tyrsa, Vera V.; Gurko, Alexander G.; Podrygalo, Mikhail A.; Lopez, Moises Rivas; Balbuena, Daniel Hernandez

    2014-03-01

    Three dimensional recording of the human body surface or anatomical areas have gained importance in many medical applications. In this paper, our 3D Medical Laser Scanner is presented. It is based on the novel principle of dynamic triangulation. We analyze the method of operation, medical applications, orthopedically diseases as Scoliosis and the most common types of skin to employ the system the most proper way. It is analyzed a group of medical problems related to the application of optical scanning in optimal way. Finally, experiments are conducted to verify the performance of the proposed system and its method uncertainty.

  3. Development of an algorithm to measure defect geometry using a 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Kilambi, S.; Tipton, S. M.

    2012-08-01

    Current fatigue life prediction models for coiled tubing (CT) require accurate measurements of the defect geometry. Three-dimensional (3D) laser imaging has shown promise toward becoming a nondestructive, non-contacting method of surface defect characterization. Laser imaging provides a detailed photographic image of a flaw, in addition to a detailed 3D surface map from which its critical dimensions can be measured. This paper describes algorithms to determine defect characteristics, specifically depth, width, length and projected cross-sectional area. Curve-fitting methods were compared and implicit algebraic fits have higher probability of convergence compared to explicit geometric fits. Among the algebraic fits, the Taubin circle fit has the least error. The algorithm was able to extract the dimensions of the flaw geometry from the scanned data of CT to within a tolerance of about 0.127 mm, close to the tolerance specified for the laser scanner itself, compared to measurements made using traveling microscopes. The algorithm computes the projected surface area of the flaw, which could previously only be estimated from the dimension measurements and the assumptions made about cutter shape. Although shadows compromised the accuracy of the shape characterization, especially for deep and narrow flaws, the results indicate that the algorithm with laser scanner can be used for non-destructive evaluation of CT in the oil field industry. Further work is needed to improve accuracy, to eliminate shadow effects and to reduce radial deviation.

  4. Calibration algorithm in robotic remanufacturing measurement system based on 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Shen, C. D.; Zhu, S.; Li, C.; Liang, Y. Y.

    2009-07-01

    In robotic remanufacturing measurement system, the 3D laser scanner is arranged by the robot and the object scanned is mounted on a turntable. This paper deals with the algorithm of calibrating the relationship between the scanner coordinate and the robot Tool0, and furthermore locating the center axis of the turntable. The data of Tool0 can be directly obtained denoting its relationship with the robot base coordinate. So, the coordinate transformation problems are effectively solved and the measuring data which relative to the robot base coordinate could be congruously saved. This paper detailed explains the basic algorithm theory, computing method and the result data analysis, and etc. The calibration algorithm is deduced under the orthogonal coordinate.

  5. Quantifying the Spatial Distribution of Hill Slope Erosion Using a 3-D Laser Scanner

    NASA Astrophysics Data System (ADS)

    Scholl, B. N.; Bogonko, M.; He, Y.; Beighley, R. E.; Milberg, C. T.

    2007-12-01

    Soil erosion is a complicated process involving many interdependent variables including rainfall intensity and duration, drop size, soil characteristics, ground cover, and surface slope. The interplay of these variables produces differing spatial patterns of rill versus inter-rill erosion by changing the effective energy from rain drop impacts and the quantities and timing of sheet and shallow, concentrated flow. The objective of this research is to characterize the spatial patterns of rill and inter-rill erosion produced from simulated rainfall on different soil densities and surface slopes using a 3-D laser scanner. The soil used in this study is a sandy loam with bulk density due to compaction ranging from 1.25-1.65 g/cm3. The surface slopes selected for this study are 25, 33, and 50 percent and represent common slopes used for grading on construction sites. The spatial patterns of soil erosion are measured using a Trimble GX DR 200+ 3D Laser Scanner which employs a time of flight calculation averaged over 4 points using a class 2, pulsed, 532 nm, green laser at a distance of 2 to 11 m from the surface. The scanner measures point locations on an approximately 5 mm grid. The pre- and post-erosion scan surfaces are compared to calculate the change in volume and the dimensions of rills and inter-rill areas. The erosion experiments were performed in the Soil Erosion Research Laboratory (SERL), part of the Civil and Environmental Engineering department at San Diego State University. SERL experiments utilize a 3-m by 10-m tilting soil bed with a soil depth of 0.5 meters. Rainfall is applied to the soil surface using two overhead Norton ladder rainfall simulators, which produce realistic rain drop diameters (median = 2.25 mm) and impact velocities. Simulated storm events used in this study consist of rainfall intensities ranging from 5, 10 to 15 cm/hr for durations of 20 to 30 minutes. Preliminary results are presented that illustrate a change in runoff processes and

  6. Comparison of clinical bracket point registration with 3D laser scanner and coordinate measuring machine

    PubMed Central

    Nouri, Mahtab; Farzan, Arash; Baghban, Ali Reza Akbarzadeh; Massudi, Reza

    2015-01-01

    OBJECTIVE: The aim of the present study was to assess the diagnostic value of a laser scanner developed to determine the coordinates of clinical bracket points and to compare with the results of a coordinate measuring machine (CMM). METHODS: This diagnostic experimental study was conducted on maxillary and mandibular orthodontic study casts of 18 adults with normal Class I occlusion. First, the coordinates of the bracket points were measured on all casts by a CMM. Then, the three-dimensional coordinates (X, Y, Z) of the bracket points were measured on the same casts by a 3D laser scanner designed at Shahid Beheshti University, Tehran, Iran. The validity and reliability of each system were assessed by means of intraclass correlation coefficient (ICC) and Dahlberg's formula. RESULTS: The difference between the mean dimension and the actual value for the CMM was 0.0066 mm. (95% CI: 69.98340, 69.99140). The mean difference for the laser scanner was 0.107 ± 0.133 mm (95% CI: -0.002, 0.24). In each method, differences were not significant. The ICC comparing the two methods was 0.998 for the X coordinate, and 0.996 for the Y coordinate; the mean difference for coordinates recorded in the entire arch and for each tooth was 0.616 mm. CONCLUSION: The accuracy of clinical bracket point coordinates measured by the laser scanner was equal to that of CMM. The mean difference in measurements was within the range of operator errors. PMID:25741826

  7. Fusion of 3D laser scanner and depth images for obstacle recognition in mobile applications

    NASA Astrophysics Data System (ADS)

    Budzan, Sebastian; Kasprzyk, Jerzy

    2016-02-01

    The problem of obstacle detection and recognition or, generally, scene mapping is one of the most investigated problems in computer vision, especially in mobile applications. In this paper a fused optical system using depth information with color images gathered from the Microsoft Kinect sensor and 3D laser range scanner data is proposed for obstacle detection and ground estimation in real-time mobile systems. The algorithm consists of feature extraction in the laser range images, processing of the depth information from the Kinect sensor, fusion of the sensor information, and classification of the data into two separate categories: road and obstacle. Exemplary results are presented and it is shown that fusion of information gathered from different sources increases the effectiveness of the obstacle detection in different scenarios, and it can be used successfully for road surface mapping.

  8. Finding the displacement of wood structure in heritage building by 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Lee, M. C.; Tsai, Y. L.; Wang, R. Z.; Lin, M. L.

    2015-08-01

    Heritage buildings are highly prone to long term damage from the microclimate, scourge and vandalism, which can result in damaged materials, structures, painting and cultural heritage items. This study will focus on finding the displacement of wood structural members through the use of a 3D laser scanner and the 4D concept of time. The results will compare the scans from different periods to find the difference (if any) in the structural member position. Wood structures usually consist of numerous wood members connected to form the structure. However, these members can be damaged in various ways such as physical mechanisms, chemical reactions, and biological corrosion. When damage to the wood structure occurs, the structural displacement can be affected, and if affected severely, can lead to a building collapse. Monitoring of the structural displacement is the best way to discover damage immediately and to preserve the heritage building. However, the Cultural Heritage Preservation Law in Taiwan prohibits the installation of monitoring instruments (e.g strain gauge, accelerometer) in historic structures (heritage buildings). Scanning the wood structure with 3D lasers is the most non-intrusive method and quickly achieves displacement through visualization. The displacement scan results can be compared with different periods and different members to analyze the severity of damage. Once the 3D scanner is installed, the whole building is scanned, and point clouds created to build the visual building model. The structural displacement can be checked via the building model and the differences are measured between each member to find the high risk damaged areas or members with large displacement. Early detection of structural damage is the most effective way means of preservation.

  9. Improvement of 3d Monte Carlo Localization Using a Depth Camera and Terrestrial Laser Scanner

    NASA Astrophysics Data System (ADS)

    Kanai, S.; Hatakeyama, R.; Date, H.

    2015-05-01

    Effective and accurate localization method in three-dimensional indoor environments is a key requirement for indoor navigation and lifelong robotic assistance. So far, Monte Carlo Localization (MCL) has given one of the promising solutions for the indoor localization methods. Previous work of MCL has been mostly limited to 2D motion estimation in a planar map, and a few 3D MCL approaches have been recently proposed. However, their localization accuracy and efficiency still remain at an unsatisfactory level (a few hundreds millimetre error at up to a few FPS) or is not fully verified with the precise ground truth. Therefore, the purpose of this study is to improve an accuracy and efficiency of 6DOF motion estimation in 3D MCL for indoor localization. Firstly, a terrestrial laser scanner is used for creating a precise 3D mesh model as an environment map, and a professional-level depth camera is installed as an outer sensor. GPU scene simulation is also introduced to upgrade the speed of prediction phase in MCL. Moreover, for further improvement, GPGPU programming is implemented to realize further speed up of the likelihood estimation phase, and anisotropic particle propagation is introduced into MCL based on the observations from an inertia sensor. Improvements in the localization accuracy and efficiency are verified by the comparison with a previous MCL method. As a result, it was confirmed that GPGPU-based algorithm was effective in increasing the computational efficiency to 10-50 FPS when the number of particles remain below a few hundreds. On the other hand, inertia sensor-based algorithm reduced the localization error to a median of 47mm even with less number of particles. The results showed that our proposed 3D MCL method outperforms the previous one in accuracy and efficiency.

  10. Comparison between 3D model of Pisciarelli area (Campi Flegrei caldera) through Terrestrial Laser Scanner

    NASA Astrophysics Data System (ADS)

    Caputo, Teresa; Somma, Renato; Marino, Ermanno; Terracciano, Rosario; Troise, Claudia; De Natale, Giuseppe

    2016-04-01

    The volcanic/geothermal area of Pisciarelli is located within Campi Flegrei caldera .This last is a densely populated area, including the Pozzuoli town and bordering the western side of the Naples city, this causes a high vulnerability and consequently a high volcanic risk. In the recent decades this area has experienced minor ground uplift episodes accompanied by low magnitude seismicity and by strong intensification of degassing activity in particular localized at Pisciarelli area. We present the results of the Terrestrial Laser Scanner (TLS), using a Reigl VZ1000®, analysis of Pisciarelli area performed in June 2013 and the comparison with the data acquired later in March 2014. We apply the TLS technique based on Time of Flight (TOF) method in order to define an accurate 3D digital model for detailed analysis of this area performing numerous scans from different points of view in the area. In this ways was ensured a good coverage of the whole investigated area in order to avoid shaded portion due to the high soil degassing activity. Such fact limits the capacity of laser penetration is caused by wavelength near infrared range. For each survey was obtained a Digital Terrain Model (DTM) from the reconstructed data and both were compared. In particular, we have identified two "critical" areas of interest that will be monitored more frequently. These are: 1) in the lower part of the studied area a major fault line that bounding the Agnano caldera moderately NE-dipping; 2) in the upper part of the study area a zone of depletion with its zone of accumulation. The DTM were georeferenced into the UTM-WGS84 reference frame. The aim of this work is to define a procedure to compare between 3D model applied to monitoring of this area. Also to evaluate of volumetric and morphologic changes and to recognizing unstable masses by comparison of 3D data. For this purpose other TLS surveys will be performed in the upcoming in this active volcanic/geothermal area.

  11. High speed micro scanner for 3D in-volume laser micro processing

    NASA Astrophysics Data System (ADS)

    Schaefer, D.; Gottmann, J.; Hermans, M.; Ortmann, J.; Kelbassa, I.

    2013-03-01

    Using an in-house developed micro scanner three-dimensional micro components and micro fluidic devices in fused silica are realized using the ISLE process (in-volume selective laser-induced etching). With the micro scanner system the potential of high average power femtosecond lasers (P > 100 W) is exploited by the fabrication of components with micrometer precision at scan speeds of several meters per second. A commercially available galvanometer scanner is combined with an acousto-optical and/or electro-optical beam deflector and translation stages. For focusing laser radiation high numerical aperture microscope objectives (NA > 0.3) are used generating a focal volume of a few cubic micrometers. After laser exposure the materials are chemically wet etched in aqueous solution. The laser-exposed material is etched whereas the unexposed material remains nearly unchanged. Using the described technique called ISLE the fabrication of three-dimensional micro components, micro holes, cuts and channels is possible with high average power femtosecond lasers resulting in a reduced processing time for exposure. By developing the high speed micro scanner up-scaling of the ISLE process is demonstrated. The fabricated components made out of glass can be applied in various markets like biological and medical diagnostics as well as in micro mechanics.

  12. 3D leaf water content mapping using terrestrial laser scanner backscatter intensity with radiometric correction

    NASA Astrophysics Data System (ADS)

    Zhu, Xi; Wang, Tiejun; Darvishzadeh, Roshanak; Skidmore, Andrew K.; Niemann, K. Olaf

    2015-12-01

    Leaf water content (LWC) plays an important role in agriculture and forestry management. It can be used to assess drought conditions and wildfire susceptibility. Terrestrial laser scanner (TLS) data have been widely used in forested environments for retrieving geometrically-based biophysical parameters. Recent studies have also shown the potential of using radiometric information (backscatter intensity) for estimating LWC. However, the usefulness of backscatter intensity data has been limited by leaf surface characteristics, and incidence angle effects. To explore the idea of using LiDAR intensity data to assess LWC we normalized (for both angular effects and leaf surface properties) shortwave infrared TLS data (1550 nm). A reflectance model describing both diffuse and specular reflectance was applied to remove strong specular backscatter intensity at a perpendicular angle. Leaves with different surface properties were collected from eight broadleaf plant species for modeling the relationship between LWC and backscatter intensity. Reference reflectors (Spectralon from Labsphere, Inc.) were used to build a look-up table to compensate for incidence angle effects. Results showed that before removing the specular influences, there was no significant correlation (R2 = 0.01, P > 0.05) between the backscatter intensity at a perpendicular angle and LWC. After the removal of the specular influences, a significant correlation emerged (R2 = 0.74, P < 0.05). The agreement between measured and TLS-derived LWC demonstrated a significant reduction of RMSE (root mean square error, from 0.008 to 0.003 g/cm2) after correcting for the incidence angle effect. We show that it is possible to use TLS to estimate LWC for selected broadleaved plants with an R2 of 0.76 (significance level α = 0.05) at leaf level. Further investigations of leaf surface and internal structure will likely result in improvements of 3D LWC mapping for studying physiology and ecology in vegetation.

  13. Practical Considerations For A Design Of A High Precision 3-D Laser Scanner System

    NASA Astrophysics Data System (ADS)

    Blais, Francois; Rioux, Marc; Beraldin, J.-Angelo

    1988-11-01

    The Laboratory for Intelligent Systems of the Division of Electrical Engineering of the National Research Council of Canada is intensively involved in the development of laser-based three-dimensional vision systems and their applications. Two basic systems have been invented. One, based on a double aperture mask in front of a CCD camera, has been developed for robotic applications and control. The other technique is based on an auto-synchronized scanning principle to provide accurate, fast, and reliable 3-D coordinates. Using the latter method, several prototypes have been developed for the acquisition of 3-D data of objects and for inspection. This paper will describe some practical considerations for the design and implementation of triangulation-based 3-D range sensors with emphasis on the latter triangulation technique. Some applications and results will be presented.

  14. Comparison of 3D representations depicting micro folds: overlapping imagery vs. time-of-flight laser scanner

    NASA Astrophysics Data System (ADS)

    Vaiopoulos, Aristidis D.; Georgopoulos, Andreas; Lozios, Stylianos G.

    2012-10-01

    A relatively new field of interest, which continuously gains grounds nowadays, is digital 3D modeling. However, the methodologies, the accuracy and the time and effort required to produce a high quality 3D model have been changing drastically the last few years. Whereas in the early days of digital 3D modeling, 3D models were only accessible to computer experts in animation, working many hours in expensive sophisticated software, today 3D modeling has become reasonably fast and convenient. On top of that, with online 3D modeling software, such as 123D Catch, nearly everyone can produce 3D models with minimum effort and at no cost. The only requirement is panoramic overlapping images, of the (still) objects the user wishes to model. This approach however, has limitations in the accuracy of the model. An objective of the study is to examine these limitations by assessing the accuracy of this 3D modeling methodology, with a Terrestrial Laser Scanner (TLS). Therefore, the scope of this study is to present and compare 3D models, produced with two different methods: 1) Traditional TLS method with the instrument ScanStation 2 by Leica and 2) Panoramic overlapping images obtained with DSLR camera and processed with 123D Catch free software. The main objective of the study is to evaluate advantages and disadvantages of the two 3D model producing methodologies. The area represented with the 3D models, features multi-scale folding in a cipollino marble formation. The most interesting part and most challenging to capture accurately, is an outcrop which includes vertically orientated micro folds. These micro folds have dimensions of a few centimeters while a relatively strong relief is evident between them (perhaps due to different material composition). The area of interest is located in Mt. Hymittos, Greece.

  15. Reconstruction of 3D tree stem models from low-cost terrestrial laser scanner data

    NASA Astrophysics Data System (ADS)

    Kelbe, Dave; Romanczyk, Paul; van Aardt, Jan; Cawse-Nicholson, Kerry

    2013-05-01

    With the development of increasingly advanced airborne sensing systems, there is a growing need to support sensor system design, modeling, and product-algorithm development with explicit 3D structural ground truth commensurate to the scale of acquisition. Terrestrial laser scanning is one such technique which could provide this structural information. Commercial instrumentation to suit this purpose has existed for some time now, but cost can be a prohibitive barrier for some applications. As such we recently developed a unique laser scanning system from readily-available components, supporting low cost, highly portable, and rapid measurement of below-canopy 3D forest structure. Tools were developed to automatically reconstruct tree stem models as an initial step towards virtual forest scene generation. The objective of this paper is to assess the potential of this hardware/algorithm suite to reconstruct 3D stem information for a single scan of a New England hardwood forest site. Detailed tree stem structure (e.g., taper, sweep, and lean) is recovered for trees of varying diameter, species, and range from the sensor. Absolute stem diameter retrieval accuracy is 12.5%, with a 4.5% overestimation bias likely due to the LiDAR beam divergence.

  16. Laser scanner data processing and 3D modeling using a free and open source software

    SciTech Connect

    Gabriele, Fatuzzo; Michele, Mangiameli Giuseppe, Mussumeci; Salvatore, Zito

    2015-03-10

    The laser scanning is a technology that allows in a short time to run the relief geometric objects with a high level of detail and completeness, based on the signal emitted by the laser and the corresponding return signal. When the incident laser radiation hits the object to detect, then the radiation is reflected. The purpose is to build a three-dimensional digital model that allows to reconstruct the reality of the object and to conduct studies regarding the design, restoration and/or conservation. When the laser scanner is equipped with a digital camera, the result of the measurement process is a set of points in XYZ coordinates showing a high density and accuracy with radiometric and RGB tones. In this case, the set of measured points is called “point cloud” and allows the reconstruction of the Digital Surface Model. Even the post-processing is usually performed by closed source software, which is characterized by Copyright restricting the free use, free and open source software can increase the performance by far. Indeed, this latter can be freely used providing the possibility to display and even custom the source code. The experience started at the Faculty of Engineering in Catania is aimed at finding a valuable free and open source tool, MeshLab (Italian Software for data processing), to be compared with a reference closed source software for data processing, i.e. RapidForm. In this work, we compare the results obtained with MeshLab and Rapidform through the planning of the survey and the acquisition of the point cloud of a morphologically complex statue.

  17. Automatic Construction of 3D Basic-Semantic Models of Inhabited Interiors Using Laser Scanners and RFID Sensors

    PubMed Central

    Valero, Enrique; Adan, Antonio; Cerrada, Carlos

    2012-01-01

    This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a selective and sequential segmentation from the cloud of points by means of different algorithms which depend on the information that the RFID tags provide. The identification of basic elements of the scene, such as walls, floor, ceiling, windows, doors, tables, chairs and cabinets, and the positioning of their corresponding models can then be calculated. The fusion of both technologies thus allows a simplified 3D semantic indoor model to be obtained. This method has been tested in real scenes under difficult clutter and occlusion conditions, and has yielded promising results. PMID:22778609

  18. Online process monitoring at quasi-simultaneous laser transmission welding using a 3D-scanner with integrated pyrometer

    NASA Astrophysics Data System (ADS)

    Schmailzl, A.; Steger, S.; Dostalek, M.; Hierl, S.

    2016-03-01

    Quasi-simultaneous laser transmission welding is a well-known joining technique for thermoplastics and mainly used in the automotive as well as in the medical industry. For process control usually the so called set-path monitoring is used, where the weld is specified as "good" if the irradiation time is inside a defined confidence interval. However, the detection of small-sized gaps or thermal damaged zones is not possible with this technique. The analyzation of the weld seam temperature during welding offers the possibility to overcome this problem. In this approach a 3D-scanner is used instead of a scanner with flat-field optic. By using a pyrometer in combination with a 3D-scanner no color-corrected optic is needed in order to provide that laser- and detection-spot are concentric. Experimental studies on polyethylene T-joints have shown that the quality of the signal is adequate, despite the use of an optical setup with a long working distance and a small optical aperture. The effects on temperature are studied for defects like a gap in the joining zone. Therefore a notch was milled into the absorbent polymer. In case of producing housings for electronic parts the effect of an electrical wire between the joining partners is also investigated. Both defects can be identified by a local temperature deviation even at a feed rate of four meters per second. Furthermore a strategy for signal-processing is demonstrated. By this, remaining defects can be identified. Consequently an online detection of local defects is possible, which makes a dynamic process control feasible.

  19. 3D modelling of Mt. Talaga Bodas Crater (Indonesia) by using terrestrial laser scanner for volcano hazard mitigation

    NASA Astrophysics Data System (ADS)

    Gumilar, Irwan; Abidin, Hasanuddin Z.; Putra, Andreas D.; Haerani, Nia

    2015-04-01

    Indonesia is a country with many volcanoes. Each volcano in Indonesia typically has its own crater characteristics. One of them is the Mt.Talaga Bodas, located in Garut, West Java. Researches regarding the crater characteristics are necessary for volcanic disaster mitigation process. One of them is the modelling of the shape of the crater. One of the methods that can be used to model the volcanic crater is using Terrestrial Laser Scanner (TLS). This research aims to create a 3 dimensional (3D) model of the crater of the Mt. Talaga Bodas, that hopefully can be utilized for volcanic disaster mitigation. The methodology used in this research is by obtaining the scanning data using TLS and GPS measurements to obtain the coordinates of the reference points. The data processing methods consist of several steps, namely target to target registration, filterization, georeference, meshing point cloud, surface making, drawing, and 3D modelling. These steps were done using the Cyclone 7 software, and also using 3DS MAX for 3D modelling. The result of this data processing is a 3D model of the crater of the Mt. Talaga Bodas which is similar with the real shape. The calculation result shows that the height of the crater is 62.522 m, the diameter of the crater is 467.231 m, and the total area is 2961054.652 m2. The main obstacle in this research is the dense vegetation which becomes the noise and affects the crater model.

  20. A comparison of multi-view 3D reconstruction of a rock wall using several cameras and a laser scanner

    NASA Astrophysics Data System (ADS)

    Thoeni, K.; Giacomini, A.; Murtagh, R.; Kniest, E.

    2014-06-01

    This work presents a comparative study between multi-view 3D reconstruction using various digital cameras and a terrestrial laser scanner (TLS). Five different digital cameras were used in order to estimate the limits related to the camera type and to establish the minimum camera requirements to obtain comparable results to the ones of the TLS. The cameras used for this study range from commercial grade to professional grade and included a GoPro Hero 1080 (5 Mp), iPhone 4S (8 Mp), Panasonic Lumix LX5 (9.5 Mp), Panasonic Lumix ZS20 (14.1 Mp) and Canon EOS 7D (18 Mp). The TLS used for this work was a FARO Focus 3D laser scanner with a range accuracy of ±2 mm. The study area is a small rock wall of about 6 m height and 20 m length. The wall is partly smooth with some evident geological features, such as non-persistent joints and sharp edges. Eight control points were placed on the wall and their coordinates were measured by using a total station. These coordinates were then used to georeference all models. A similar number of images was acquired from a distance of between approximately 5 to 10 m, depending on field of view of each camera. The commercial software package PhotoScan was used to process the images, georeference and scale the models, and to generate the dense point clouds. Finally, the open-source package CloudCompare was used to assess the accuracy of the multi-view results. Each point cloud obtained from a specific camera was compared to the point cloud obtained with the TLS. The latter is taken as ground truth. The result is a coloured point cloud for each camera showing the deviation in relation to the TLS data. The main goal of this study is to quantify the quality of the multi-view 3D reconstruction results obtained with various cameras as objectively as possible and to evaluate its applicability to geotechnical problems.

  1. Applications of Non-destructive methods (GPR and 3D Laser Scanner) in Historic Masonry Arch Bridge Assessment

    NASA Astrophysics Data System (ADS)

    Alani, Amir; Banks, Kevin

    2014-05-01

    There exist approximately 70,000 masonry arch bridge spans (brick and stone) in the UK with tens of thousands more throughout Europe. A significant number of these bridges are still in operation and form part of the road and rail network systems in many countries. A great majority of these bridges are in desperate need of repair and maintenance. Applications of non-destructive testing methods such as ground penetrating radar (GPR), 3D laser scanning, accelerometer sensors and vibration detecting sensors amongst many others have been used to assess and monitor such structures in the past few years. This presentation provides results of the applications of a 2GHz GPR antenna system and a 3D laser scanner on a historic masonry arch bridge (the Old Bridge, Aylesford) located in Kent, in the south east of England. The older part of the bridge (the mid-span) is 860 years old. The bridge was the subject of a major alteration in 1811. This presentation forms part of a larger ongoing study which is using the two above mentioned non-destructive methods for long-term monitoring of the bridge. The adopted survey planning strategy and technique, data acquisition and processing as well as challenges encountered during actual survey and fieldworks have been discussed in this presentation. As a result of this study the position of different layers of the deck structure has been established with the identification of the original stone base of the bridge. This information in addition to the location of a number of structural ties (anchors - remedial work carried out previously) in the absence of reliable and accurate design details proved to be extremely useful for the modelling of the bridge using the finite element method. Results of the 3D laser scanning of the bridge have also been presented which have provided invaluable data essential for the accurate modelling of the bridge as well as the long term monitoring of the bridge. 2014 EGU-GA GI3.1 Session, organised by COST Action

  2. Uav-Based Acquisition of 3d Point Cloud - a Comparison of a Low-Cost Laser Scanner and Sfm-Tools

    NASA Astrophysics Data System (ADS)

    Mader, D.; Blaskow, R.; Westfeld, P.; Maas, H.-G.

    2015-08-01

    The Project ADFEX (Adaptive Federative 3D Exploration of Multi Robot System) pursues the goal to develop a time- and cost-efficient system for exploration and monitoring task of unknown areas or buildings. A fleet of unmanned aerial vehicles equipped with appropriate sensors (laser scanner, RGB camera, near infrared camera, thermal camera) were designed and built. A typical operational scenario may include the exploration of the object or area of investigation by an UAV equipped with a laser scanning range finder to generate a rough point cloud in real time to provide an overview of the object on a ground station as well as an obstacle map. The data about the object enables the path planning for the robot fleet. Subsequently, the object will be captured by a RGB camera mounted on the second flying robot for the generation of a dense and accurate 3D point cloud by using of structure from motion techniques. In addition, the detailed image data serves as basis for a visual damage detection on the investigated building. This paper focuses on our experience with use of a low-cost light-weight Hokuyo laser scanner onboard an UAV. The hardware components for laser scanner based 3D point cloud acquisition are discussed, problems are demonstrated and analyzed, and a quantitative analysis of the accuracy potential is shown as well as in comparison with structure from motion-tools presented.

  3. Surveying and mapping a cave using 3d laser scanner: the open challenge with free and open source software

    NASA Astrophysics Data System (ADS)

    Cosso, T.; Ferrando, I.; Orlando, A.

    2014-06-01

    The present work is part of a series of activities involving different skills, in order to explore and document in detail one of the most visited caves in Liguria Region. In this context, in addition to speleologists, geologists, videographers, the geomatic expertise has also been involved to carry out a laser scanner survey, in order to produce a three-dimensional model of the two more easily accessible rooms of the cave. The survey was carried out using Z+F IMAGER® 5010 instrument and the post processing operations related to registration of point clouds have been made with Z+F LaserControl®. Subsequently, two different free and open source software were used: MeshLab, to merge the point clouds and to obtain the final mesh, and CloudCompare, to make filtering on the previous results and to extract sections.

  4. Accuracy of 3D scanners in tooth mark analysis.

    PubMed

    Molina, Ana; Martin-de-las-Heras, Stella

    2015-01-01

    The objective of this study was to compare the accuracy of contact and laser 3D scanners in tooth mark analysis. Ten dental casts were scanned with both 3D scanners. Seven linear measurements were made from the 3D images of dental casts and biting edges generated with DentalPrint© software (University of Granada, Granada, Spain). The uncertainty value for contact 3D scanning was 0.833 for the upper dental cast and 0.660 mm for the lower cast; similar uncertainty values were found for 3D-laser scanning. Slightly higher uncertainty values were obtained for the 3D biting edges generated. The uncertainty values for single measurements ranged from 0.1 to 0.3 mm with the exception of the intercanine distance, in which higher values were obtained. Knowledge of the error rate in the 3D scanning of dental casts and biting edges is especially relevant to be applied in practical forensic cases. PMID:25388960

  5. Boresight Calibration of Construction Misalignments for 3D Scanners Built with a 2D Laser Rangefinder Rotating on Its Optical Center

    PubMed Central

    Morales, Jesús; Martínez, Jorge L.; Mandow, Anthony; Reina, Antonio J.; Pequeño-Boter, Alejandro; García-Cerezo, Alfonso

    2014-01-01

    Many applications, like mobile robotics, can profit from acquiring dense, wide-ranging and accurate 3D laser data. Off-the-shelf 2D scanners are commonly customized with an extra rotation as a low-cost, lightweight and low-power-demanding solution. Moreover, aligning the extra rotation axis with the optical center allows the 3D device to maintain the same minimum range as the 2D scanner and avoids offsets in computing Cartesian coordinates. The paper proposes a practical procedure to estimate construction misalignments based on a single scan taken from an arbitrary position in an unprepared environment that contains planar surfaces of unknown dimensions. Inherited measurement limitations from low-cost 2D devices prevent the estimation of very small translation misalignments, so the calibration problem reduces to obtaining boresight parameters. The distinctive approach with respect to previous plane-based intrinsic calibration techniques is the iterative maximization of both the flatness and the area of visible planes. Calibration results are presented for a case study. The method is currently being applied as the final stage in the production of a commercial 3D rangefinder. PMID:25347585

  6. Boresight calibration of construction misalignments for 3D scanners built with a 2D laser range finder rotating on its optical center.

    PubMed

    Morales, Jesús; Martínez, Jorge L; Mandow, Anthony; Reina, Antonio J; Pequeño-Boter, Alejandro; García-Cerezo, Alfonso

    2014-01-01

    Many applications, like mobile robotics, can profit from acquiring dense, wide-ranging and accurate 3D laser data. Off-the-shelf 2D scanners are commonly customized with an extra rotation as a low-cost, lightweight and low-power-demanding solution. Moreover, aligning the extra rotation axis with the optical center allows the 3D device to maintain the same minimum range as the 2D scanner and avoids offsets in computing Cartesian coordinates. The paper proposes a practical procedure to estimate construction misalignments based on a single scan taken from an arbitrary position in an unprepared environment that contains planar surfaces of unknown dimensions. Inherited measurement limitations from low-cost 2D devices prevent the estimation of very small translation misalignments, so the calibration problem reduces to obtaining boresight parameters. The distinctive approach with respect to previous plane-based intrinsic calibration techniques is the iterative maximization of both the flatness and the area of visible planes. Calibration results are presented for a case study. The method is currently being applied as the final stage in the production of a commercial 3D rangefinder. PMID:25347585

  7. Comparison of Cyberware PX and PS 3D human head scanners

    NASA Astrophysics Data System (ADS)

    Carson, Jeremy; Corner, Brian D.; Crockett, Eric; Li, Peng; Paquette, Steven

    2008-02-01

    A common limitation of laser line three-Dimensional (3D) scanners is the inability to scan objects with surfaces that are either parallel to the laser line or that self-occlude. Filling in missing areas adds some unwanted inaccuracy to the 3D model. Capturing the human head with a Cyberware PS Head Scanner is an example of obtaining a model where the incomplete areas are difficult to fill accurately. The PS scanner uses a single vertical laser line to illuminate the head and is unable to capture data at top of the head, where the line of sight is tangent to the surface, and under the chin, an area occluded by the chin when the subject looks straight forward. The Cyberware PX Scanner was developed to obtain this missing 3D head data. The PX scanner uses two cameras offset at different angles to provide a more detailed head scan that captures surfaces missed by the PS scanner. The PX scanner cameras also use new technology to obtain color maps that are of higher resolution than the PS Scanner. The two scanners were compared in terms of amount of surface captured (surface area and volume) and the quality of head measurements when compared to direct measurements obtained through standard anthropometry methods. Relative to the PS scanner, the PX head scans were more complete and provided the full set of head measurements, but actual measurement values, when available from both scanners, were about the same.

  8. A 3D airborne ultrasound scanner

    NASA Astrophysics Data System (ADS)

    Capineri, L.; Masotti, L.; Rocchi, S.

    1998-06-01

    This work investigates the feasibility of an ultrasound scanner designed to reconstruct three-dimensional profiles of objects in air. There are many industrial applications in which it is important to obtain quickly and accurately the digital reconstruction of solid objects with contactless methods. The final aim of this project was the profile reconstruction of shoe lasts in order to eliminate the mechanical tracers from the reproduction process of shoe prototypes. The feasibility of an ultrasonic scanner was investigated in laboratory conditions on wooden test objects with axial symmetry. A bistatic system based on five airborne polyvinylidenedifluoride (PVDF) transducers was mechanically moved to emulate a cylindrical array transducer that can host objects of maximum width and height 20 cm and 40 cm respectively. The object reconstruction was based on a simplified version of the synthetic aperture focusing technique (SAFT): the time of flight (TOF) of the first in time echo for each receiving transducer was taken into account, a coarse spatial sampling of the ultrasonic field reflected on the array transducer was delivered and the reconstruction algorithm was based on the ellipsoidal backprojection. Measurements on a wooden cone section provided submillimetre accuracy in a controlled environment.

  9. Uncertainty Propagation for Terrestrial Mobile Laser Scanner

    NASA Astrophysics Data System (ADS)

    Mezian, c.; Vallet, Bruno; Soheilian, Bahman; Paparoditis, Nicolas

    2016-06-01

    Laser scanners are used more and more in mobile mapping systems. They provide 3D point clouds that are used for object reconstruction and registration of the system. For both of those applications, uncertainty analysis of 3D points is of great interest but rarely investigated in the literature. In this paper we present a complete pipeline that takes into account all the sources of uncertainties and allows to compute a covariance matrix per 3D point. The sources of uncertainties are laser scanner, calibration of the scanner in relation to the vehicle and direct georeferencing system. We suppose that all the uncertainties follow the Gaussian law. The variances of the laser scanner measurements (two angles and one distance) are usually evaluated by the constructors. This is also the case for integrated direct georeferencing devices. Residuals of the calibration process were used to estimate the covariance matrix of the 6D transformation between scanner laser and the vehicle system. Knowing the variances of all sources of uncertainties, we applied uncertainty propagation technique to compute the variance-covariance matrix of every obtained 3D point. Such an uncertainty analysis enables to estimate the impact of different laser scanners and georeferencing devices on the quality of obtained 3D points. The obtained uncertainty values were illustrated using error ellipsoids on different datasets.

  10. Whole-body 3D scanner and scan data report

    NASA Astrophysics Data System (ADS)

    Addleman, Stephen R.

    1997-03-01

    With the first whole-body 3D scanner now available the next adventure confronting the user is what to do with all of the data. While the system was built for anthropologists, it has created interest among users from a wide variety of fields. Users with applications in the fields of anthropology, costume design, garment design, entertainment, VR and gaming have a need for the data in formats unique to their fields. Data from the scanner is being converted to solid models for art and design and NURBS for computer graphics applications. Motion capture has made scan data move and dance. The scanner has created a need for advanced application software just as other scanners have in the past.

  11. Development of a 3D CT scanner using cone beam

    NASA Astrophysics Data System (ADS)

    Endo, Masahiro; Kamagata, Nozomu; Sato, Kazumasa; Hattori, Yuichi; Kobayashi, Shigeo; Mizuno, Shinichi; Jimbo, Masao; Kusakabe, Masahiro

    1995-05-01

    In order to acquire 3D data of high contrast objects such as bone, lung and vessels enhanced by contrast media for use in 3D image processing, we have developed a 3D CT-scanner using cone beam x ray. The 3D CT-scanner consists of a gantry and a patient couch. The gantry consists of an x-ray tube designed for cone beam CT and a large area two-dimensional detector mounted on a single frame and rotated around an object in 12 seconds. The large area detector consists of a fluorescent plate and a charge coupled device video camera. The size of detection area was 600 mm X 450 mm capable of covering the total chest. While an x-ray tube was rotated around an object, pulsed x ray was exposed 30 times a second and 360 projected images were collected in a 12 second scan. A 256 X 256 X 256 matrix image (1.25 mm X 1.25 mm X 1.25 mm voxel) was reconstructed by a high-speed reconstruction engine. Reconstruction time was approximately 6 minutes. Cylindrical water phantoms, anesthetized rabbits with or without contrast media, and a Japanese macaque were scanned with the 3D CT-scanner. The results seem promising because they show high spatial resolution in three directions, though there existed several point to be improved. Possible improvements are discussed.

  12. Hybrid Dispersion Laser Scanner

    PubMed Central

    Goda, K.; Mahjoubfar, A.; Wang, C.; Fard, A.; Adam, J.; Gossett, D. R.; Ayazi, A.; Sollier, E.; Malik, O.; Chen, E.; Liu, Y.; Brown, R.; Sarkhosh, N.; Di Carlo, D.; Jalali, B.

    2012-01-01

    Laser scanning technology is one of the most integral parts of today's scientific research, manufacturing, defense, and biomedicine. In many applications, high-speed scanning capability is essential for scanning a large area in a short time and multi-dimensional sensing of moving objects and dynamical processes with fine temporal resolution. Unfortunately, conventional laser scanners are often too slow, resulting in limited precision and utility. Here we present a new type of laser scanner that offers ∼1,000 times higher scan rates than conventional state-of-the-art scanners. This method employs spatial dispersion of temporally stretched broadband optical pulses onto the target, enabling inertia-free laser scans at unprecedented scan rates of nearly 100 MHz at 800 nm. To show our scanner's broad utility, we use it to demonstrate unique and previously difficult-to-achieve capabilities in imaging, surface vibrometry, and flow cytometry at a record 2D raster scan rate of more than 100 kHz with 27,000 resolvable points. PMID:22685627

  13. Dynamic Analysis of 2D Electromagnetic Resonant Optical Scanner Using 3D Finite Element Method

    NASA Astrophysics Data System (ADS)

    Hirata, Katsuhiro; Hong, Sara; Maeda, Kengo

    The optical scanner is a scanning device in which a laser beam is reflected by a mirror that can be rotated or oscillated. In this paper, we propose a new 2D electromagnetic resonant optical scanner that employs electromagnets and leaf springs. Torque characteristics and resonance characteristics of the scanner are analyzed using the 3D finite element method. The validity of the analysis is shown by comparing the characteristics inferred from the analysis with the characteristics of the prototype. Further, 2D resonance is investigated by introducing a superimposed-frequency current in a single coil.

  14. Metrological verification of 3D scanners: a preliminary approach

    NASA Astrophysics Data System (ADS)

    Anchini, R.; Di Leo, G.; Liguori, C.; Paolillo, A.; Pietrosanto, A.; Strazzullo, G.

    2007-01-01

    The paper deals with the metrological characterization of 3D scanners, and proposes a procedure for their experimental verification in accord with the suggestions of the ISO GUM. The procedure is based on the application of a statistical method for the evaluation of the standard uncertainty to the results of a comparison with a Coordinate Measuring Machine (CMM). Finally the results of the experimental verification of a fringe pattern system are reported and discussed in detail.

  15. Restitution of sculptural groups using 3D scanners.

    PubMed

    Merchán, Pilar; Salamanca, Santiago; Adán, Antonio

    2011-01-01

    Imagine for a moment that you have to solve a 3D jigsaw of which you have lost several pieces. You have also lost the original box-top showing the final picture, and as if that were not enough, some of the pieces you do have may belong to some other jigsaw. This is in essence the sort of challenge that we faced in the novel project that we shall be describing in this paper. The final aim of the project was, with the help of 3D scanners, to digitalize and reconstruct multi-piece classical sculptures. Particularly, we tackle the restitution of the so-called "Aeneas Group", a famous iconographic reference during the Roman Empire. We have undertaken this ambitious project in collaboration with the research department of the Spanish National Museum of Roman Art (MNAR). This paper summarizes the real problems that arose and had to be solved, the innovations, and the main results of the work that we have carried out over these recent years. PMID:22164088

  16. Restitution of Sculptural Groups Using 3D Scanners

    PubMed Central

    Merchán, Pilar; Salamanca, Santiago; Adán, Antonio

    2011-01-01

    Imagine for a moment that you have to solve a 3D jigsaw of which you have lost several pieces. You have also lost the original box-top showing the final picture, and as if that were not enough, some of the pieces you do have may belong to some other jigsaw. This is in essence the sort of challenge that we faced in the novel project that we shall be describing in this paper. The final aim of the project was, with the help of 3D scanners, to digitalize and reconstruct multi-piece classical sculptures. Particularly, we tackle the restitution of the so-called “Aeneas Group”, a famous iconographic reference during the Roman Empire. We have undertaken this ambitious project in collaboration with the research department of the Spanish National Museum of Roman Art (MNAR). This paper summarizes the real problems that arose and had to be solved, the innovations, and the main results of the work that we have carried out over these recent years. PMID:22164088

  17. Precise Indoor Localization for Mobile Laser Scanner

    NASA Astrophysics Data System (ADS)

    Kaijaluoto, R.; Hyyppä, A.

    2015-05-01

    Accurate 3D data is of high importance for indoor modeling for various applications in construction, engineering and cultural heritage documentation. For the lack of GNSS signals hampers use of kinematic platforms indoors, TLS is currently the most accurate and precise method for collecting such a data. Due to its static single view point data collection, excessive time and data redundancy are needed for integrity and coverage of data. However, localization methods with affordable scanners are used for solving mobile platform pose problem. The aim of this study was to investigate what level of trajectory accuracies can be achieved with high quality sensors and freely available state of the art planar SLAM algorithms, and how well this trajectory translates to a point cloud collected with a secondary scanner. In this study high precision laser scanners were used with a novel way to combine the strengths of two SLAM algorithms into functional method for precise localization. We collected five datasets using Slammer platform with two laser scanners, and processed them with altogether 20 different parameter sets. The results were validated against TLS reference. The results show increasing scan frequency improves the trajectory, reaching 20 mm RMSE levels for the best performing parameter sets. Further analysis of the 3D point cloud showed good agreement with TLS reference with 17 mm positional RMSE. With precision scanners the obtained point cloud allows for high level of detail data for indoor modeling with accuracies close to TLS at best with vastly improved data collection efficiency.

  18. Data Integration Acquired from Micro-Uav and Terrestrial Laser Scanner for the 3d Mapping of Jesuit Ruins of São Miguel das Missões

    NASA Astrophysics Data System (ADS)

    Reiss, M. L. L.; da Rocha, R. S.; Ferraz, R. S.; Cruz, V. C.; Morador, L. Q.; Yamawaki, M. K.; Rodrigues, E. L. S.; Cole, J. O.; Mezzomo, W.

    2016-06-01

    The Jesuit Missions the Guaranis were one of the great examples of cultural, social, and scientific of the eighteenth century, which had its decline from successive wars that followed the exchange of territories domain occupied by Portugal and Spain with the Madrid Treaty of January 13, 1750. One of the great examples of this development is materialized in the ruins of 30 churches and villages that remain in a territory that now comprises part of Brazil, Argentina and Paraguay. These Churches, São Miguel das Missões is among the Brazilian ruins, the best preserved. The ruins of São Miguel das Missões were declared a UNESCO World Cultural Heritage in 1983 and the Institute of National Historical Heritage (IPHAN) is the Brazilian Federal agency that manages and maintains this heritage. In order to produce a geographic database to assist the IPHAN in the management of the Ruins of São Miguel das Missões it was proposed a three-dimensional mapping of these ruins never performed in this location before. The proposal is integrated data acquired from multiple sensors: two micro-UAV, an Asctec Falcon 8 (rotary wing) and a Sensefly e-Bee (fixed wing); photos from terrestrial cameras; two terrestrial LIDAR sensors, one Faro Focus 3D S-120 and Optec 3D-HD ILRIS. With this abundance of sensors has been possible to perform comparisons and integration of the acquired data, and produce a 3D reconstruction of the church with high completeness and accuracy (better than 25 mm), as can be seen in the presentation of this work.

  19. Data Integration Acquired from Micro-Uav and Terrestrial Laser Scanner for the 3d Mapping of Jesuit Ruins of SÃO Miguel das MISSÕES

    NASA Astrophysics Data System (ADS)

    Reiss, M. L. L.; da Rocha, R. S.; Ferraz, R. S.; Cruz, V. C.; Morador, L. Q.; Yamawaki, M. K.; Rodrigues, E. L. S.; Cole, J. O.; Mezzomo, W.

    2016-06-01

    The Jesuit Missions the Guaranis were one of the great examples of cultural, social, and scientific of the eighteenth century, which had its decline from successive wars that followed the exchange of territories domain occupied by Portugal and Spain with the Madrid Treaty of January 13, 1750. One of the great examples of this development is materialized in the ruins of 30 churches and villages that remain in a territory that now comprises part of Brazil, Argentina and Paraguay. These Churches, São Miguel das Missões is among the Brazilian ruins, the best preserved. The ruins of São Miguel das Missões were declared a UNESCO World Cultural Heritage in 1983 and the Institute of National Historical Heritage (IPHAN) is the Brazilian Federal agency that manages and maintains this heritage. In order to produce a geographic database to assist the IPHAN in the management of the Ruins of São Miguel das Missões it was proposed a three-dimensional mapping of these ruins never performed in this location before. The proposal is integrated data acquired from multiple sensors: two micro-UAV, an Asctec Falcon 8 (rotary wing) and a Sensefly e-Bee (fixed wing); photos from terrestrial cameras; two terrestrial LIDAR sensors, one Faro Focus 3D S-120 and Optec 3D-HD ILRIS. With this abundance of sensors has been possible to perform comparisons and integration of the acquired data, and produce a 3D reconstruction of the church with high completeness and accuracy (better than 25 mm), as can be seen in the presentation of this work.

  20. A new methodology in fast and accurate matching of the 2D and 3D point clouds extracted by laser scanner systems

    NASA Astrophysics Data System (ADS)

    Torabi, M.; Mousavi G., S. M.; Younesian, D.

    2015-03-01

    Registration of the point clouds is a conventional challenge in computer vision related applications. As an application, matching of train wheel profiles extracted from two viewpoints is studied in this paper. The registration problem is formulated into an optimization problem. An error minimization function for registration of the two partially overlapping point clouds is presented. The error function is defined as the sum of the squared distance between the source points and their corresponding pairs which should be minimized. The corresponding pairs are obtained thorough Iterative Closest Point (ICP) variants. Here, a point-to-plane ICP variant is employed. Principal Component Analysis (PCA) is used to obtain tangent planes. Thus it is shown that minimization of the proposed objective function diminishes point-to-plane ICP variant. We utilized this algorithm to register point clouds of two partially overlapping profiles of wheel train extracted from two viewpoints in 2D. Also, a number of synthetic point clouds and a number of real point clouds in 3D are studied to evaluate the reliability and rate of convergence in our method compared with other registration methods.

  1. Hybrid 3D laser sensor based on a high-performance long-range wide-field-of-view laser scanner and a calibrated high-resolution digital camera

    NASA Astrophysics Data System (ADS)

    Ullrich, Andreas; Studnicka, Nikolaus; Riegl, Johannes

    2004-09-01

    We present a hybrid sensor consisting of a high-performance 3D imaging laser sensor and a high-resolution digital camera. The laser sensor uses the time-of-flight principle based on near-infrared pulses. We demonstrate the performance capabilities of the system by presenting example data and we describe the software package used for data acquisition, data merging and visualization. The advantages of using both, near range photogrammetry and laser scanning, for data registration and data extraction are discussed.

  2. Fiber optic coherent laser radar 3D vision system

    SciTech Connect

    Clark, R.B.; Gallman, P.G.; Slotwinski, A.R.; Wagner, K.; Weaver, S.; Xu, Jieping

    1996-12-31

    This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution.

  3. Real time 3D scanner: investigations and results

    NASA Astrophysics Data System (ADS)

    Nouri, Taoufik; Pflug, Leopold

    1993-12-01

    This article presents a concept of reconstruction of 3-D objects using non-invasive and touch loss techniques. The principle of this method is to display parallel interference optical fringes on an object and then to record the object under two angles of view. According to an appropriated treatment one reconstructs the 3-D object even when the object has no symmetrical plan. The 3-D surface data is available immediately in digital form for computer- visualization and for analysis software tools. The optical set-up for recording the 3-D object, the 3-D data extraction and treatment, as well as the reconstruction of the 3-D object are reported and commented on. This application is dedicated for reconstructive/cosmetic surgery, CAD, animation and research purposes.

  4. 3D Laser Scanning in Technology Education.

    ERIC Educational Resources Information Center

    Flowers, Jim

    2000-01-01

    A three-dimensional laser scanner can be used as a tool for design and problem solving in technology education. A hands-on experience can enhance learning by captivating students' interest and empowering them with creative tools. (Author/JOW)

  5. Fiber optic coherent laser radar 3d vision system

    SciTech Connect

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-12-31

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  6. Laser printing of 3D metallic interconnects

    NASA Astrophysics Data System (ADS)

    Beniam, Iyoel; Mathews, Scott A.; Charipar, Nicholas A.; Auyeung, Raymond C. Y.; Piqué, Alberto

    2016-04-01

    The use of laser-induced forward transfer (LIFT) techniques for the printing of functional materials has been demonstrated for numerous applications. The printing gives rise to patterns, which can be used to fabricate planar interconnects. More recently, various groups have demonstrated electrical interconnects from laser-printed 3D structures. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or of pastes containing dispersed metallic particles. However, the generated 3D structures do not posses the same metallic conductivity as a bulk metal interconnect of the same cross-section and length as those formed by wire bonding or tab welding. An alternative is to laser transfer entire 3D structures using a technique known as lase-and-place. Lase-and-place is a LIFT process whereby whole components and parts can be transferred from a donor substrate onto a desired location with one single laser pulse. This paper will describe the use of LIFT to laser print freestanding, solid metal foils or beams precisely over the contact pads of discrete devices to interconnect them into fully functional circuits. Furthermore, this paper will also show how the same laser can be used to bend or fold the bulk metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief for the circuits under flexing or during motion from thermal mismatch. These interconnect "ridges" can span wide gaps (on the order of a millimeter) and accommodate height differences of tens of microns between adjacent devices. Examples of these laser printed 3D metallic bridges and their role in the development of next generation electronics by additive manufacturing will be presented.

  7. Precision 3-D microscopy with intensity modulated fibre optic scanners

    NASA Astrophysics Data System (ADS)

    Olmos, P.

    2016-01-01

    Optical 3-D imagers constitute a family of precision and useful instruments, easily available on the market in a wide variety of configurations and performances. However, besides their cost they usually provide an image of the object (i.e. a more or less faithful representation of the reality) instead of a truly object's reconstruction. Depending on the detailed working principles of the equipment, this reconstruction may become a challenging task. Here a very simple yet reliable device is described; it is able to form images of opaque objects by illuminating them with an optical fibre and collecting the reflected light with another fibre. Its 3-D capability comes from the spatial filtering imposed by the fibres together with their movement (scanning) along the three directions: transversal (surface) and vertical. This unsophisticated approach allows one to model accurately the entire optical process and to perform the desired reconstruction, finding that information about the surface which is of interest: its profile and its reflectance, ultimately related to the type of material.

  8. Fast, high-resolution 3D dosimetry utilizing a novel optical-CT scanner incorporating tertiary telecentric collimation.

    PubMed

    Sakhalkar, H S; Oldham, M

    2008-01-01

    This study introduces a charge coupled device (CCD) area detector based optical-computed tomography (optical-CT) scanner for comprehensive verification of radiation dose distributions recorded in nonscattering radiochromic dosimeters. Defining characteristics include: (i) a very fast scanning time of approximately 5 min to acquire a complete three-dimensional (3D) dataset, (ii) improved image formation through the use of custom telecentric optics, which ensures accurate projection images and minimizes artifacts from scattered and stray-light sources, and (iii) high resolution (potentially 50 microm) isotropic 3D dose readout. The performance of the CCD scanner for 3D dose readout was evaluated by comparison with independent 3D readout from the single laser beam OCTOPUS-scanner for the same PRESAGE dosimeters. The OCTOPUS scanner was considered the "gold standard" technique in light of prior studies demonstrating its accuracy. Additional comparisons were made against calculated dose distributions from the ECLIPSE treatment-planning system. Dose readout for the following treatments were investigated: (i) a single rectangular beam irradiation to investigate small field and very steep dose gradient dosimetry away from edge effects, (ii) a 2-field open beam parallel-opposed irradiation to investigate dosimetry along steep dose gradients, and (iii) a 7-field intensity modulated radiation therapy (IMRT) irradiation to investigate dosimetry for complex treatment delivery involving modulation of fluence and for dosimetry along moderate dose gradients. Dose profiles, dose-difference plots, and gamma maps were employed to evaluate quantitative estimates of agreement between independently measured and calculated dose distributions. Results indicated that dose readout from the CCD scanner was in agreement with independent gold-standard readout from the OCTOPUS-scanner as well as the calculated ECLIPSE dose distribution for all treatments, except in regions within a few

  9. Precision Control Module For UV Laser 3D Micromachining

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Hong; Hung, Min-Wei; Chang, Chun-Li

    2011-01-01

    UV laser has been widely used in various micromachining such as micro-scribing or patterning processing. At present, most of the semiconductors, LEDs, photovoltaic solar panels and touch panels industries need the UV laser processing system. However, most of the UV laser processing applications in the industries utilize two dimensional (2D) plane processing. And there are tremendous business opportunities that can be developed, such as three dimensional (3D) structures of micro-electromechanical (MEMS) sensor or the precision depth control of indium tin oxide (ITO) thin films edge insulation in touch panels. This research aims to develop a UV laser 3D micromachining module that can create the novel applications for industries. By special designed beam expender in optical system, the focal point of UV laser can be adjusted quickly and accurately through the optical path control lens of laser beam expender optical system. Furthermore, the integrated software for galvanometric scanner and focal point adjustment mechanism is developed as well, so as to carry out the precise 3D microstructure machining.

  10. Optical scanner. [laser doppler velocimeters

    NASA Technical Reports Server (NTRS)

    Rhodes, D. B. (Inventor)

    1977-01-01

    An optical scanner that sequentially focuses optical energy (light) at selected points in space is described. The essential component is a scanning wheel including several glass windows with each window having a different thickness. Due to this difference in thickness, the displacement of the emerging light from the incident light is different for each window. The scanner transmits optical energy to a point in space while at the same time receiving any optical energy generated at that point and then moves on to the next selected point and repeats this transmit and receive operation. It fills the need for a system that permits a laser velocimeter to rapidly scan across a constantly changing flow field in an aerodynamic test facility.

  11. Laser 3D micro-manufacturing

    NASA Astrophysics Data System (ADS)

    Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

    2016-06-01

    Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

  12. 3D Laser Triangulation for Plant Phenotyping in Challenging Environments

    PubMed Central

    Kjaer, Katrine Heinsvig; Ottosen, Carl-Otto

    2015-01-01

    To increase the understanding of how the plant phenotype is formed by genotype and environmental interactions, simple and robust high-throughput plant phenotyping methods should be developed and considered. This would not only broaden the application range of phenotyping in the plant research community, but also increase the ability for researchers to study plants in their natural environments. By studying plants in their natural environment in high temporal resolution, more knowledge on how multiple stresses interact in defining the plant phenotype could lead to a better understanding of the interaction between plant responses and epigenetic regulation. In the present paper, we evaluate a commercial 3D NIR-laser scanner (PlantEye, Phenospex B.V., Herleen, The Netherlands) to track daily changes in plant growth with high precision in challenging environments. Firstly, we demonstrate that the NIR laser beam of the scanner does not affect plant photosynthetic performance. Secondly, we demonstrate that it is possible to estimate phenotypic variation amongst the growth pattern of ten genotypes of Brassica napus L. (rapeseed), using a simple linear correlation between scanned parameters and destructive growth measurements. Our results demonstrate the high potential of 3D laser triangulation for simple measurements of phenotypic variation in challenging environments and in a high temporal resolution. PMID:26066990

  13. A prototype fan-beam optical CT scanner for 3D dosimetry

    SciTech Connect

    Campbell, Warren G.; Rudko, D. A.; Braam, Nicolas A.; Jirasek, Andrew; Wells, Derek M.

    2013-06-15

    Purpose: The objective of this work is to introduce a prototype fan-beam optical computed tomography scanner for three-dimensional (3D) radiation dosimetry. Methods: Two techniques of fan-beam creation were evaluated: a helium-neon laser (HeNe, {lambda} = 543 nm) with line-generating lens, and a laser diode module (LDM, {lambda} = 635 nm) with line-creating head module. Two physical collimator designs were assessed: a single-slot collimator and a multihole collimator. Optimal collimator depth was determined by observing the signal of a single photodiode with varying collimator depths. A method of extending the dynamic range of the system is presented. Two sample types were used for evaluations: nondosimetric absorbent solutions and irradiated polymer gel dosimeters, each housed in 1 liter cylindrical plastic flasks. Imaging protocol investigations were performed to address ring artefacts and image noise. Two image artefact removal techniques were performed in sinogram space. Collimator efficacy was evaluated by imaging highly opaque samples of scatter-based and absorption-based solutions. A noise-based flask registration technique was developed. Two protocols for gel manufacture were examined. Results: The LDM proved advantageous over the HeNe laser due to its reduced noise. Also, the LDM uses a wavelength more suitable for the PRESAGE{sup TM} dosimeter. Collimator depth of 1.5 cm was found to be an optimal balance between scatter rejection, signal strength, and manufacture ease. The multihole collimator is capable of maintaining accurate scatter-rejection to high levels of opacity with scatter-based solutions (T < 0.015%). Imaging protocol investigations support the need for preirradiation and postirradiation scanning to reduce reflection-based ring artefacts and to accommodate flask imperfections and gel inhomogeneities. Artefact removal techniques in sinogram space eliminate streaking artefacts and reduce ring artefacts of up to {approx}40% in magnitude. The

  14. Laser Scanner For Automatic Storage

    NASA Astrophysics Data System (ADS)

    Carvalho, Fernando D.; Correia, Bento A.; Rebordao, Jose M.; Rodrigues, F. Carvalho

    1989-01-01

    The automated magazines are beeing used at industry more and more. One of the problems related with the automation of a Store House is the identification of the products envolved. Already used for stock management, the Bar Codes allows an easy way to identify one product. Applied to automated magazines, the bar codes allows a great variety of items in a small code. In order to be used by the national producers of automated magazines, a devoted laser scanner has been develloped. The Prototype uses an He-Ne laser whose beam scans a field angle of 75 degrees at 16 Hz. The scene reflectivity is transduced by a photodiode into an electrical signal, which is then binarized. This digital signal is the input of the decodifying program. The machine is able to see barcodes and to decode the information. A parallel interface allows the comunication with the central unit, which is responsible for the management of automated magazine.

  15. D Super-Resolution Approach for Sparse Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    Hosseinyalamdary, S.; Yilmaz, A.

    2015-08-01

    Laser scanner point cloud has been emerging in Photogrammetry and computer vision to achieve high level tasks such as object tracking, object recognition and scene understanding. However, low cost laser scanners are noisy, sparse and prone to systematic errors. This paper proposes a novel 3D super resolution approach to reconstruct surface of the objects in the scene. This method works on sparse, unorganized point clouds and has superior performance over other surface recovery approaches. Since the proposed approach uses anisotropic diffusion equation, it does not deteriorate the object boundaries and it preserves topology of the object.

  16. FELIX: a volumetric 3D laser display

    NASA Astrophysics Data System (ADS)

    Bahr, Detlef; Langhans, Knut; Gerken, Martin; Vogt, Carsten; Bezecny, Daniel; Homann, Dennis

    1996-03-01

    In this paper, an innovative approach of a true 3D image presentation in a space filling, volumetric laser display will be described. The introduced prototype system is based on a moving target screen that sweeps the display volume. Net result is the optical equivalent of a 3D array of image points illuminated to form a model of the object which occupies a physical space. Wireframe graphics are presented within the display volume which a group of people can walk around and examine simultaneously from nearly any orientation and without any visual aids. Further to the detailed vector scanning mode, a raster scanned system and a combination of both techniques are under development. The volumetric 3D laser display technology for true reproduction of spatial images can tremendously improve the viewers ability to interpret data and to reliably determine distance, shape and orientation. Possible applications for this development range from air traffic control, where moving blips of light represent individual aircrafts in a true to scale projected airspace of an airport, to various medical applications (e.g. electrocardiography, computer-tomography), to entertainment and education visualization as well as imaging in the field of engineering and Computer Aided Design.

  17. Evaluation of 3D surface scanners for skin documentation in forensic medicine: comparison of benchmark surfaces

    PubMed Central

    Schweitzer, Wolf; Häusler, Martin; Bär, Walter; Schaepman, Michael

    2007-01-01

    Background Two 3D surface scanners using collimated light patterns were evaluated in a new application domain: to document details of surfaces similar to the ones encountered in forensic skin pathology. Since these scanners have not been specifically designed for forensic skin pathology, we tested their performance under practical constraints in an application domain that is to be considered new. Methods Two solid benchmark objects containing relevant features were used to compare two 3D surface scanners: the ATOS-II (GOM, Germany) and the QTSculptor (Polygon Technology, Germany). Both scanners were used to capture and process data within a limited amount of time, whereas point-and-click editing was not allowed. We conducted (a) a qualitative appreciation of setup, handling and resulting 3D data, (b) an experimental subjective evaluation of matching 3D data versus photos of benchmark object regions by a number of 12 judges who were forced to state their preference for either of the two scanners, and (c) a quantitative characterization of both 3D data sets comparing 220 single surface areas with the real benchmark objects in order to determine the recognition rate's possible dependency on feature size and geometry. Results The QTSculptor generated significantly better 3D data in both qualitative tests (a, b) that we had conducted, possibly because of a higher lateral point resolution; statistical evaluation (c) showed that the QTSculptor-generated data allowed the discrimination of features as little as 0.3 mm, whereas ATOS-II-generated data allowed for discrimination of features sized not smaller than 1.2 mm. Conclusion It is particularly important to conduct specific benchmark tests if devices are brought into new application domains they were not specifically designed for; using a realistic test featuring forensic skin pathology features, QT Sculptor-generated data quantitatively exceeded manufacturer's specifications, whereas ATOS-II-generated data was within

  18. Color influence on accuracy of 3D scanners based on structured light

    NASA Astrophysics Data System (ADS)

    Voisin, Sophie; Page, David L.; Foufou, Sebti; Truchetet, Frédéric; Abidi, Mongi A.

    2006-02-01

    The characterization of commercial 3D scanners allows acquiring precise and useful data. The accuracy of range and, more recently, color for 3D scanners is usually studied separately, but when the 3D scanner is based on structured light with a color coding pattern, color influence on range accuracy should be investigated. The commercial product that we have tested has the particularity that it can acquire data under ambient light instead of a controlled environment as it is with most available scanners. Therefore, based on related work in the literature and on experiments we have done on a variety of standard illuminants, we have designed an interesting setup to control illuminant interference. Basically, the setup consists of acquiring the well-known Macbeth ColorChecker under a controlled environment and also ambient daylight. The results have shown variations with respect to the color. We have performed several statistical studies to show how the range results evolve with respect to the RGB and the HSV channels. In addition, a systematic noise error has also been identified. This noise depends on the object color. A subset of colors shows strong noise errors while other colors have minimal or even no systematic error under the same illuminant.

  19. Fusion of Terrestrial and Airborne Laser Data for 3D modeling Applications

    NASA Astrophysics Data System (ADS)

    Mohammed, Hani Mahmoud

    This thesis deals with the 3D modeling phase of the as-built large BIM projects. Among several means of BIM data capturing, such as photogrammetric or range tools, laser scanners have been one of the most efficient and practical tool for a long time. They can generate point clouds with high resolution for 3D models that meet nowadays' market demands. The current 3D modeling projects of as-built BIMs are mainly focused on using one type of laser scanner data, such as Airborne or Terrestrial. According to the literatures, no significant (few) efforts were made towards the fusion of heterogeneous laser scanner data despite its importance. The importance of the fusion of heterogeneous data arises from the fact that no single type of laser data can provide all the information about BIM, especially for large BIM projects that are existing on a large area, such as university buildings, or Heritage places. Terrestrial laser scanners are able to map facades of buildings and other terrestrial objects. However, they lack the ability to map roofs or higher parts in the BIM project. Airborne laser scanner on the other hand, can map roofs of the buildings efficiently and can map only small part of the facades. Short range laser scanners can map the interiors of the BIM projects, while long range scanners are used for mapping wide exterior areas in BIM projects. In this thesis the long range laser scanner data obtained in the Stop-and-Go mapping mode, the short range laser scanner data, obtained in a fully static mapping mode, and the airborne laser data are all fused together to bring a complete effective solution for a large BIM project. Working towards the 3D modeling of BIM projects, the thesis framework starts with the registration of the data, where a new fast automatic registration algorithm were developed. The next step is to recognize the different objects in the BIM project (classification), and obtain 3D models for the buildings. The last step is the development of an

  20. Optical CT scanner for in-air readout of gels for external radiation beam 3D dosimetry.

    PubMed

    Ramm, Daniel; Rutten, Thomas P; Shepherd, Justin; Bezak, Eva

    2012-06-21

    Optical CT scanners for a 3D readout of externally irradiated radiosensitive hydrogels currently require the use of a refractive index (RI) matching liquid bath to obtain suitable optical ray paths through the gel sample to the detector. The requirement for a RI matching liquid bath has been negated by the design of a plastic cylindrical gel container that provides parallel beam geometry through the gel sample for the majority of the projection. The design method can be used for various hydrogels. Preliminary test results for the prototype laser beam scanner with ferrous xylenol-orange gel show geometric distortion of 0.2 mm maximum, spatial resolution limited to beam spot size of about 0.4 mm and 0.8% noise (1 SD) for a uniform irradiation. Reconstruction of a star pattern irradiated through the cylinder walls demonstrates the suitability for external beam applications. The extremely simple and cost-effective construction of this optical CT scanner, together with the simplicity of scanning gel samples without RI matching fluid increases the feasibility of using 3D gel dosimetry for clinical external beam dose verifications. PMID:22644104

  1. Fast laser optical CT scanner with rotating mirror and Fresnel lenses

    NASA Astrophysics Data System (ADS)

    Conklin, J.; Deshpande, R.; Battista, J.; Jordan, K.

    2006-12-01

    Single laser beam and detector computed tomography (CT) scanner geometries provide excellent stray light rejection and these systems likely provide the largest dynamic range for optical CT scanning of gel dosimeters. In this work a rotating mirror, lens pair, laser scanner has been developed for a 10 x 15 cm2 field of view demonstrating a fast 3D single ray-detector optical CT scanner.

  2. Non-contact 3D fingerprint scanner using structured light illumination

    NASA Astrophysics Data System (ADS)

    Troy, Mike; Hassebrook, Laurence; Yalla, Veeraganesh; Daley, Raymond

    2011-03-01

    As crime prevention and national security remain a top priority, requirements for the use of fingerprints for identification continue to grow. While the size of fingerprint databases continues to expand, new technologies that can improve accuracy and ultimately matching performance will become more critical to maintain the effectiveness of the systems. FlashScan3D has developed non-contact, fingerprint scanners based on the principles of Structured Light Illumination (SLI) that capture 3Dimensional data of fingerprints quickly, accurately and independently of an operator. FlashScan3D will present findings from various research projects performed for the US Army and the Department of Homeland Security.

  3. Quick and low cost measurement of soil parameters using a Kinect 3D scanner

    NASA Astrophysics Data System (ADS)

    Hut, R.; Van De Giesen, N.; Hagenaars, R.

    2013-12-01

    Retrieval of basic soil parameters such as bulk density and soil moisture from soil samples is a costly and time-consuming activity. Although indirect methods (heat or electromagnetic probes, radar backscatter, etc) are abundant, field truth measurement of soil parameters will remain important, if only to calibrate these other methods. We present a quick, field mountable setup to make 3D scans of surfaces up to 30 x 30 cm using a Kinect 3D scanner. By making scans before and after samples are taken, parameters such as bulk density and moisture content can easily be calculated.

  4. Pragmatic fully 3D image reconstruction for the MiCES mouse imaging PET scanner

    NASA Astrophysics Data System (ADS)

    Lee, Kisung; Kinahan, Paul E.; Fessler, Jeffrey A.; Miyaoka, Robert S.; Janes, Marie; Lewellen, Tom K.

    2004-10-01

    We present a pragmatic approach to image reconstruction for data from the micro crystal elements system (MiCES) fully 3D mouse imaging positron emission tomography (PET) scanner under construction at the University of Washington. Our approach is modelled on fully 3D image reconstruction used in clinical PET scanners, which is based on Fourier rebinning (FORE) followed by 2D iterative image reconstruction using ordered-subsets expectation-maximization (OSEM). The use of iterative methods allows modelling of physical effects (e.g., statistical noise, detector blurring, attenuation, etc), while FORE accelerates the reconstruction process by reducing the fully 3D data to a stacked set of independent 2D sinograms. Previous investigations have indicated that non-stationary detector point-spread response effects, which are typically ignored for clinical imaging, significantly impact image quality for the MiCES scanner geometry. To model the effect of non-stationary detector blurring (DB) in the FORE+OSEM(DB) algorithm, we have added a factorized system matrix to the ASPIRE reconstruction library. Initial results indicate that the proposed approach produces an improvement in resolution without an undue increase in noise and without a significant increase in the computational burden. The impact on task performance, however, remains to be evaluated.

  5. An efficient solid modeling system based on a hand-held 3D laser scan device

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2014-12-01

    The hand-held 3D laser scanner sold in the market is appealing for its port and convenient to use, but price is expensive. To develop such a system based cheap devices using the same principles as the commercial systems is impossible. In this paper, a simple hand-held 3D laser scanner is developed based on a volume reconstruction method using cheap devices. Unlike convenient laser scanner to collect point cloud of an object surface, the proposed method only scan few key profile curves on the surface. Planar section curve network can be generated from these profile curves to construct a volume model of the object. The details of design are presented, and illustrated by the example of a complex shaped object.

  6. A protocol for evaluating the accuracy of 3D body scanners.

    PubMed

    Kouchi, Makiko; Mochimaru, Masaaki; Bradtmiller, Bruce; Daanen, Hein; Li, Peng; Nacher, Beatriz; Nam, Yunja

    2012-01-01

    Scan-derived landmarks locations and surface shapes are more and more used, but there is no commonly accepted protocol for evaluating the accuracy of these measurements. Therefore we propose a protocol for evaluating the accuracy of surface shape and the repeatability of scan-derived landmark locations. According to existing Japanese and German domestic standards, we propose to use an artefact (e.g. sphere with diameter of about 120 mm) calibrated very accurately for evaluating the accuracy of scanner-systems. For evaluating the repeatability of landmark locations, we propose to use an anthropomorphic dummy with landmark locations premarked. These test objects are measured by a 3D body scanner to be evaluated. Evaluation parameters such as trueness, precision, and repeatability are calculated from the measured data. A round-robin test was conducted in six different institutes using 17 body/head/foot scanners produced by eight companies. The purposes of the roundrobin test were to evaluate the availability of test objects to different body scanners, and to examine the measurement locations of test objects and quality parameters to be reported. As a result, the proposed test objects could be measured and the data exported by all scanner systems except one, which could not export the ball measurement. For a comparative purpose, a figure of measured surface might be useful. PMID:22317336

  7. Fusion of laser and image sensory data for 3-D modeling of the free navigation space

    NASA Technical Reports Server (NTRS)

    Mass, M.; Moghaddamzadeh, A.; Bourbakis, N.

    1994-01-01

    A fusion technique which combines two different types of sensory data for 3-D modeling of a navigation space is presented. The sensory data is generated by a vision camera and a laser scanner. The problem of different resolutions for these sensory data was solved by reduced image resolution, fusion of different data, and use of a fuzzy image segmentation technique.

  8. Single-Event-Upset Laser Scanner With Optical Bias

    NASA Technical Reports Server (NTRS)

    Kim, Quiesup

    1992-01-01

    Light-assisted microelectronic advanced laser scanner (LAMEALS) is augmented version of microelectronic advanced laser scanner (MEALS) described in article, "Laser Scanner Tests For Single-Event Upsets", (NPO-18216). Only major difference, steady illumination from helium/neon laser, argon-ion laser, and/or other source(s) combined with pulsed dye-laser illumination of MEALS into single illuminating beam.

  9. Digital Hammurabi: design and development of a 3D scanner for cuneiform tablets

    NASA Astrophysics Data System (ADS)

    Hahn, Daniel V.; Duncan, Donald D.; Baldwin, Kevin C.; Cohen, Jonathon D.; Purnomo, Budirijanto

    2006-02-01

    Cuneiform is an ancient form of writing in which wooden reeds were used to impress shapes upon moist clay tablets. Upon drying, the tablets preserved the written script with remarkable accuracy and durability. There are currently hundreds of thousands of cuneiform tablets spread throughout the world in both museums and private collections. The global scale of these artifacts presents several problems for scholars who wish to study them. It may be difficult or impossible to obtain access to a given collection. In addition, photographic records of the tablets many times prove to be inadequate for proper examination. Photographs lack the ability to alter the lighting conditions and view direction. As a solution to these problems, we describe a 3D scanner capable of acquiring the shape, color, and reflectance of a tablet as a complete 3D object. This data set could then be stored in an online library and manipulated by suitable rendering software that would allow a user to specify any view direction and lighting condition. The scanner utilizes a camera and telecentric lens to acquire images of the tablet under varying controlled illumination conditions. Image data are processed using photometric stereo and structured light techniques to determine the tablet shape; color information is reconstructed from primary color monochrome image data. The scanned surface is sampled at 26.8 μm lateral spacing and the height information is calculated on a much smaller scale. Scans of adjacent tablet sides are registered together to form a 3D surface model.

  10. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    NASA Astrophysics Data System (ADS)

    van der Sterre, Boy-Santhos; Hut, Rolf; van de Giesen, Nick

    2013-04-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the 150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  11. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    NASA Astrophysics Data System (ADS)

    van der Sterre, B.; Hut, R.; Van De Giesen, N.

    2012-12-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the $150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  12. 3D scene reconstruction based on 3D laser point cloud combining UAV images

    NASA Astrophysics Data System (ADS)

    Liu, Huiyun; Yan, Yangyang; Zhang, Xitong; Wu, Zhenzhen

    2016-03-01

    It is a big challenge capturing and modeling 3D information of the built environment. A number of techniques and technologies are now in use. These include GPS, and photogrammetric application and also remote sensing applications. The experiment uses multi-source data fusion technology for 3D scene reconstruction based on the principle of 3D laser scanning technology, which uses the laser point cloud data as the basis and Digital Ortho-photo Map as an auxiliary, uses 3DsMAX software as a basic tool for building three-dimensional scene reconstruction. The article includes data acquisition, data preprocessing, 3D scene construction. The results show that the 3D scene has better truthfulness, and the accuracy of the scene meet the need of 3D scene construction.

  13. Estimation of foot pressure from human footprint depths using 3D scanner

    NASA Astrophysics Data System (ADS)

    Wibowo, Dwi Basuki; Haryadi, Gunawan Dwi; Priambodo, Agus

    2016-03-01

    The analysis of normal and pathological variation in human foot morphology is central to several biomedical disciplines, including orthopedics, orthotic design, sports sciences, and physical anthropology, and it is also important for efficient footwear design. A classic and frequently used approach to study foot morphology is analysis of the footprint shape and footprint depth. Footprints are relatively easy to produce and to measure, and they can be preserved naturally in different soils. In this study, we need to correlate footprint depth with corresponding foot pressure of individual using 3D scanner. Several approaches are used for modeling and estimating footprint depths and foot pressures. The deepest footprint point is calculated from z max coordinate-z min coordinate and the average of foot pressure is calculated from GRF divided to foot area contact and identical with the average of footprint depth. Evaluation of footprint depth was found from importing 3D scanner file (dxf) in AutoCAD, the z-coordinates than sorted from the highest to the lowest value using Microsoft Excel to make footprinting depth in difference color. This research is only qualitatif study because doesn't use foot pressure device as comparator, and resulting the maximum pressure on calceneus is 3.02 N/cm2, lateral arch is 3.66 N/cm2, and metatarsal and hallux is 3.68 N/cm2.

  14. Development of a novel laser range scanner

    NASA Astrophysics Data System (ADS)

    Pheiffer, Thomas S.; Lennon, Brian; Simpson, Amber L.; Miga, Michael I.

    2011-03-01

    Laser range scanning an organ surface intraoperatively provides a cost effective and accurate means of measuring geometric changes in tissue. A novel laser range scanner with integrated tracking was designed, developed, and analyzed with the goal of providing intraoperative surface data during neurosurgery. The scanner is fitted with passive spheres to be optically tracked in the operating room. The design notably includes a single-lens system capable of acquiring the geometric information (as a Cartesian point cloud) via laser illumination and charge-coupled device (CCD) collection, as well as the color information via visible light collection on the same CCD. The geometric accuracy was assessed by scanning a machined phantom of known dimensions and comparing relative distances of landmarks from the point cloud to the known distances. The ability of the scanner to be tracked was first evaluated by perturbing its orientation in front of the optical tracking camera and recording the number of spheres visible to the camera at each orientation, and then by observing the variance in point cloud locations of a fixed object when the tracking camera is moved around the scanner. The scanning accuracy test resulted in an RMS error of 0.47 mm with standard deviation of 0.40 mm. The sphere visibility test showed that four diodes were visible in most of the probable operating orientations, and the overall tracking standard deviation was observed to be 1.49 mm. Intraoperative collection of cortical surface scans using the new scanner is currently underway.

  15. Laser scanners: from industrial to biomedical applications

    NASA Astrophysics Data System (ADS)

    Duma, Virgil-Florin

    2013-11-01

    We present a brief overview of our contributions in the field of laser scanning technologies, applied for a variety of applications, from industrial, dimensional measurements to high-end biomedical imaging, such as Optical Coherence Tomography (OCT). Polygon Mirror (PM) scanners are presented, as applied from optical micrometers to laser sources scanned in frequency for Swept Sources (SSs) OCT. Galvanometer-based scanners (GSs) are approached to determine the optimal scanning function in order to obtain the highest possible duty cycle. We demonstrated that this optimal scanning function is linear plus parabolic, and not linear plus sinusoidal, as it has been previously considered in the literature. Risley prisms (rotational double wedges) scanners are pointed out, with our exact approach to determine and simulate their scan patterns in order to optimize their use in several types of applications, including OCT. A discussion on the perspectives of scanning in biomedical imaging, with a focus on OCT concludes the study.

  16. Comparison of 3d Reconstruction Services and Terrestrial Laser Scanning for Cultural Heritage Documentation

    NASA Astrophysics Data System (ADS)

    Rasztovits, S.; Dorninger, P.

    2013-07-01

    Terrestrial Laser Scanning (TLS) is an established method to reconstruct the geometrical surface of given objects. Current systems allow for fast and efficient determination of 3D models with high accuracy and richness in detail. Alternatively, 3D reconstruction services are using images to reconstruct the surface of an object. While the instrumental expenses for laser scanning systems are high, upcoming free software services as well as open source software packages enable the generation of 3D models using digital consumer cameras. In addition, processing TLS data still requires an experienced user while recent web-services operate completely automatically. An indisputable advantage of image based 3D modeling is its implicit capability for model texturing. However, the achievable accuracy and resolution of the 3D models is lower than those of laser scanning data. Within this contribution, we investigate the results of automated web-services for image based 3D model generation with respect to a TLS reference model. For this, a copper sculpture was acquired using a laser scanner and using image series of different digital cameras. Two different webservices, namely Arc3D and AutoDesk 123D Catch were used to process the image data. The geometric accuracy was compared for the entire model and for some highly structured details. The results are presented and interpreted based on difference models. Finally, an economical comparison of the generation of the models is given considering the interactive and processing time costs.

  17. Gabor-domain optical coherence microscopy with integrated dual-axis MEMS scanner for fast 3D imaging and metrology

    NASA Astrophysics Data System (ADS)

    Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Santhanam, Anand P.; Tankam, Patrice; Rolland, Jannick P.

    2015-10-01

    Fast, robust, nondestructive 3D imaging is needed for characterization of microscopic structures in industrial and clinical applications. A custom micro-electromechanical system (MEMS)-based 2D scanner system was developed to achieve 55 kHz A-scan acquisition in a Gabor-domain optical coherence microscopy (GD-OCM) instrument with a novel multilevel GPU architecture for high-speed imaging. GD-OCM yields high-definition volumetric imaging with dynamic depth of focusing through a bio-inspired liquid lens-based microscope design, which has no moving parts and is suitable for use in a manufacturing setting or in a medical environment. A dual-axis MEMS mirror was chosen to replace two single-axis galvanometer mirrors; as a result, the astigmatism caused by the mismatch between the optical pupil and the scanning location was eliminated and a 12x reduction in volume of the scanning system was achieved. Imaging at an invariant resolution of 2 μm was demonstrated throughout a volume of 1 × 1 × 0.6 mm3, acquired in less than 2 minutes. The MEMS-based scanner resulted in improved image quality, increased robustness and lighter weight of the system - all factors that are critical for on-field deployment. A custom integrated feedback system consisting of a laser diode and a position-sensing detector was developed to investigate the impact of the resonant frequency of the MEMS and the driving signal of the scanner on the movement of the mirror. Results on the metrology of manufactured materials and characterization of tissue samples with GD-OCM are presented.

  18. Full-hand 3D non-contact scanner using sub-window-based structured light-illumination technique

    NASA Astrophysics Data System (ADS)

    Yalla, Veeraganesh; Hassebrook, Laurence; Daley, Ray; Boles, Colby; Troy, Mike

    2012-06-01

    Fingerprint identification is a well-regarded and widely accepted modality in the field of biometrics for its high recognition rates. Legacy 2D contact based methods, though highly evolved in terms of technology suffer from certain drawbacks. Being contact based, there are many known issues which affect the recognition rates. Flashscan3D/University of Kentucky (UKY) developed state of the art 3D non-contact fingerprint scanners using different structured light illumination (SLI) techniques namely SLI single Point Of View (POV) and the SLI Subwindowing techniques. Capturing the fingerprints by non-contact means in 3D gives much higher quality fingerprint data which ultimately improves matching rates over a traditional 2D approach. In this paper, we present a full hand 3D non-contact scanner using the SLI Sub-windowing technique. Sample fingerprint data and experimental results for fingerprint matching based on a small sample 3D fingerprint test set are presented.

  19. High precision kinematic surveying with laser scanners

    NASA Astrophysics Data System (ADS)

    Gräfe, Gunnar

    2007-12-01

    The kinematic survey of roads and railways is becoming a much more common data acquisition method. The development of the Mobile Road Mapping System (MoSES) has reached a level that allows the use of kinematic survey technology for high precision applications. The system is equipped with cameras and laser scanners. For high accuracy requirements, the scanners become the main sensor group because of their geometric precision and reliability. To guarantee reliable survey results, specific calibration procedures have to be applied, which can be divided into the scanner sensor calibration as step 1, and the geometric transformation parameter estimation with respect to the vehicle coordinate system as step 2. Both calibration steps include new methods for sensor behavior modeling and multisensor system integration. To verify laser scanner quality of the MoSES system, the results are regularly checked along different test routes. It can be proved that a standard deviation of 0.004 m for height of the scanner points will be obtained, if the specific calibrations and data processing methods are applied. This level of accuracy opens new possibilities to serve engineering survey applications using kinematic measurement techniques. The key feature of scanner technology is the full digital coverage of the road area. Three application examples illustrate the capabilities. Digital road surface models generated from MoSES data are used, especially for road surface reconstruction tasks along highways. Compared to static surveys, the method offers comparable accuracy at higher speed, lower costs, much higher grid resolution and with greater safety. The system's capability of gaining 360 profiles leads to other complex applications like kinematic tunnel surveys or the precise analysis of bridge clearances.

  20. 3D reconstruction with two webcams and a laser line projector

    NASA Astrophysics Data System (ADS)

    Li, Dongdong; Hui, Bingwei; Qiu, Shaohua; Wen, Gongjian

    2014-09-01

    Three-dimensional (3D) reconstruction is one of the most attractive research topics in photogrammetry and computer vision. Nowadays 3D reconstruction with simple and consumable equipment plays an important role. In this paper, a 3D reconstruction desktop system is built based on binocular stereo vision using a laser scanner. The hardware requirements are a simple commercial hand-held laser line projector and two common webcams for image acquisition. Generally, 3D reconstruction based on passive triangulation methods requires point correspondences among various viewpoints. The development of matching algorithms remains a challenging task in computer vision. In our proposal, with the help of a laser line projector, stereo correspondences are established robustly from epipolar geometry and the laser shadow on the scanned object. To establish correspondences more conveniently, epipolar rectification is employed using Bouguet's method after stereo calibration with a printed chessboard. 3D coordinates of the observed points are worked out with rayray triangulation and reconstruction outliers are removed with the planarity constraint of the laser plane. Dense 3D point clouds are derived from multiple scans under different orientations. Each point cloud is derived by sweeping the laser plane across the object requiring 3D reconstruction. The Iterative Closest Point algorithm is employed to register the derived point clouds. Rigid body transformation between neighboring scans is obtained to get the complete 3D point cloud. Finally polygon meshes are reconstructed from the derived point cloud and color images are used in texture mapping to get a lifelike 3D model. Experiments show that our reconstruction method is simple and efficient.

  1. Application of a Hybrid 3D-2D Laser Scanning System to the Characterization of Slate Slabs

    PubMed Central

    López, Marcos; Martínez, Javier; Matías, José María; Vilán, José Antonio; Taboada, Javier

    2010-01-01

    Dimensional control based on 3D laser scanning techniques is widely used in practice. We describe the application of a hybrid 3D-2D laser scanning system to the characterization of slate slabs with structural defects that are difficult for the human eye to characterize objectively. Our study is based on automating the process using a 3D laser scanner and a 2D camera. Our results demonstrate that the application of this hybrid system optimally characterizes slate slabs in terms of the defects described by the Spanish UNE-EN 12326-1 standard. PMID:22219696

  2. 3D integrated hybrid silicon laser.

    PubMed

    Song, Bowen; Stagarescu, Cristian; Ristic, Sasa; Behfar, Alex; Klamkin, Jonathan

    2016-05-16

    Lasers were realized on silicon by flip-chip bonding of indium phosphide (InP) devices containing total internal reflection turning mirrors for surface emission. Light is coupled to the silicon waveguides through surface grating couplers. With this technique, InP lasers were integrated on silicon. Laser cavities were also formed by coupling InP reflective semiconductor optical amplifiers to microring resonator filters and distributed Bragg reflector mirrors. Single-mode continuous wave lasing was demonstrated with a side mode suppression ratio of 30 dB. Up to 2 mW of optical power was coupled to the silicon waveguide. Thermal simulations were also performed to evaluate the low thermal impedance afforded by this architecture and potential for high wall-plug efficiency. PMID:27409867

  3. 3D laser imaging for concealed object identification

    NASA Astrophysics Data System (ADS)

    Berechet, Ion; Berginc, Gérard; Berechet, Stefan

    2014-09-01

    This paper deals with new optical non-conventional 3D laser imaging. Optical non-conventional imaging explores the advantages of laser imaging to form a three-dimensional image of the scene. 3D laser imaging can be used for threedimensional medical imaging, topography, surveillance, robotic vision because of ability to detect and recognize objects. In this paper, we present a 3D laser imaging for concealed object identification. The objective of this new 3D laser imaging is to provide the user a complete 3D reconstruction of the concealed object from available 2D data limited in number and with low representativeness. The 2D laser data used in this paper come from simulations that are based on the calculation of the laser interactions with the different interfaces of the scene of interest and from experimental results. We show the global 3D reconstruction procedures capable to separate objects from foliage and reconstruct a threedimensional image of the considered object. In this paper, we present examples of reconstruction and completion of three-dimensional images and we analyse the different parameters of the identification process such as resolution, the scenario of camouflage, noise impact and lacunarity degree.

  4. Characterizing targets and backgrounds for 3D laser radars

    NASA Astrophysics Data System (ADS)

    Steinvall, Ove K.; Larsson, Hakan; Gustafsson, Frank; Chevalier, Tomas R.; Persson, Asa; Klasen, Lena M.

    2004-12-01

    Exciting development is taking place in 3 D sensing laser radars. Scanning systems are well established for mapping from airborne and ground sensors. 3 D sensing focal plane arrays (FPAs) enable a full range and intensity image can be captured in one laser shot. Gated viewing systems also produces 3 D target information. Many applications for 3 D laser radars are found in robotics, rapid terrain visualization, augmented vision, reconnaissance and target recognition, weapon guidance including aim point selection and others. The net centric warfare will demand high resolution geo-data for a common description of the environment. At FOI we have a measurement program to collect data relevant for 3 D laser radars using airborne and tripod mounted equipment for data collection. Data collection spans from single pixel waveform collection (1 D) over 2 D using range gated imaging to full 3 D imaging using scanning systems. This paper will describe 3 D laser data from different campaigns with emphasis on range distribution and reflections properties for targets and background during different seasonal conditions. Example of the use of the data for system modeling, performance prediction and algorithm development will be given. Different metrics to characterize the data set will also be discussed.

  5. Comparison of physical quality assurance between Scanora 3D and 3D Accuitomo 80 dental CT scanners

    PubMed Central

    Ali, Ahmed S.; Fteita, Dareen; Kulmala, Jarmo

    2015-01-01

    Background The use of cone beam computed tomography (CBCT) in dentistry has proven to be useful in the diagnosis and treatment planning of several oral and maxillofacial diseases. The quality of the resulting image is dictated by many factors related to the patient, unit, and operator. Materials and methods In this work, two dental CBCT units, namely Scanora 3D and 3D Accuitomo 80, were assessed and compared in terms of quantitative effective dose delivered to specific locations in a dosimetry phantom. Resolution and contrast were evaluated in only 3D Accuitomo 80 using special quality assurance phantoms. Results Scanora 3D, with less radiation time, showed less dosing values compared to 3D Accuitomo 80 (mean 0.33 mSv, SD±0.16 vs. 0.18 mSv, SD±0.1). Using paired t-test, no significant difference was found in Accuitomo two scan sessions (p>0.05), while it was highly significant in Scanora (p>0.05). The modulation transfer function value (at 2 lp/mm), in both measurements, was found to be 4.4%. The contrast assessment of 3D Accuitomo 80 in the two measurements showed few differences, for example, the grayscale values were the same (SD=0) while the noise level was slightly different (SD=0 and 0.67, respectively). Conclusions The radiation dose values in these two CBCT units are significantly less than those encountered in systemic CT scans. However, the dose seems to be affected more by changing the field of view rather than the voltage or amperage. The low doses were at the expense of the image quality produced, which was still acceptable. Although the spatial resolution and contrast were inferior to the medical images produced in systemic CT units, the present results recommend adopting CBCTs in maxillofacial imaging because of low radiation dose and adequate image quality. PMID:26091832

  6. Laser profiling of 3D microturbine blades

    NASA Astrophysics Data System (ADS)

    Holmes, Andrew S.; Heaton, Mark E.; Hong, Guodong; Pullen, Keith R.; Rumsby, Phil T.

    2003-11-01

    We have used KrF excimer laser ablation in the fabrication of a novel MEMS power conversion device based on an axial-flow turbine with an integral axial-flux electromagnetic generator. The device has a sandwich structure, comprising a pair of silicon stators either side of an SU8 polymer rotor. The curved turbine rotor blades were fabricated by projection ablation of SU8 parts performed by conventional UV lithography. A variable aperture mask, implemented by stepping a moving aperture in front of a fixed one, was used to achieve the desired spatial variation in the ablated depth. An automatic process was set up on a commercial laser workstation, with the laser firing and mask motion being controlled by computer. High quality SU8 rotor parts with diameters of 13 mm and depths of 1 mm were produced at a fluence of 0.7 J/cm2, corresponding to a material removal rate of approximately 0.3 μm per pulse. A similar approach was used to form SU8 guide vane inserts for the stators.

  7. Fast 3D shape measurements using laser speckle projection

    NASA Astrophysics Data System (ADS)

    Schaffer, Martin; Grosse, Marcus; Harendt, Bastian; Kowarschik, Richard

    2011-05-01

    3D measurement setups based on structured light projection are widely used for many industrial applications. Due to intense research in the past the accuracy is comparably high in connection with relatively low cost of the equipment. But facing higher acquisition rates in industries especially for chain assembling lines there are still hurdles to take when accelerating 3D measurements and at the same time retaining accuracies. We developed a projection technique that uses laser speckles to enable fast 3D measurements with statistically structured light patterns. In combination with a temporal correlation technique dense and accurate 3D reconstructions at nearly video rate can be achieved.

  8. Interferometric Laser Scanner for Direction Determination.

    PubMed

    Kaloshin, Gennady; Lukin, Igor

    2016-01-01

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5-10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km. PMID:26805841

  9. Interferometric Laser Scanner for Direction Determination

    PubMed Central

    Kaloshin, Gennady; Lukin, Igor

    2016-01-01

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km. PMID:26805841

  10. A laser scanner for 35mm film

    NASA Technical Reports Server (NTRS)

    Callen, W. R.; Weaver, J. E.

    1977-01-01

    The design, construction, and testing of a laser scanning system is described. The scanner was designed to deliver a scanned beam over a 2.54 cm by 2.54 cm or a 5.08 cm by 5.08 cm format. In order to achieve a scan resolution and rate comparable to that of standard television, an acousto-optic deflector was used for one axis of the scan, and a light deflecting galvanometer for deflection along the other axis. The acoustic optic deflector has the capability of random access scan controlled by a digital computer.

  11. System analysis of bar code laser scanner

    NASA Astrophysics Data System (ADS)

    Wang, Jianpu; Chen, Zhaofeng; Lu, Zukang

    1996-10-01

    This paper focuses on realizing the three important aspects of bar code scanner: generating a high quality scanning light beam, acquiring a fairly even distribution characteristic of light collection, achieving a low signal dynamic range over a large depth of field. To do this, we analyze the spatial distribution and propagation characteristics of scanning laser beam, the vignetting characteristic of optical collection system and their respective optimal design; propose a novel optical automatic gain control method to attain a constant collection over a large working depth.

  12. 3D Lasers Increase Efficiency, Safety of Moving Machines

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Canadian company Neptec Design Group Ltd. developed its Laser Camera System, used by shuttles to render 3D maps of their hulls for assessing potential damage. Using NASA funding, the firm incorporated LiDAR technology and created the TriDAR 3D sensor. Its commercial arm, Neptec Technologies Corp., has sold the technology to Orbital Sciences, which uses it to guide its Cygnus spacecraft during rendezvous and dock operations at the International Space Station.

  13. Assessment of a Static Multibeam Sonar Scanner for 3d Surveying in Confined Subaquatic Environments

    NASA Astrophysics Data System (ADS)

    Moisan, E.; Charbonnier, P.; Foucher, P.; Grussenmeyer, P.; Guillemin, S.; Samat, O.; Pagès, C.

    2016-06-01

    Mechanical Scanning Sonar (MSS) is a promising technology for surveying underwater environments. Such devices are comprised of a multibeam echosounder attached to a pan & tilt positioner, that allows sweeping the scene in a similar way as Terrestrial Laser Scanners (TLS). In this paper, we report on the experimental assessment of a recent MSS, namely, the BlueView BV5000, in a confined environment: lock number 50 on the Marne-Rhin canal (France). To this aim, we hung the system upside-down to scan the lock chamber from the surface, which allows surveying the scanning positions, up to an horizontal orientation. We propose a geometric method to estimate the remaining angle and register the scans in a coordinate system attached to the site. After reviewing the different errors that impair sonar data, we compare the resulting point cloud to a TLS model that was acquired the day before, while the lock was completely empty for maintenance. While the results exhibit a bias that can be partly explained by an imperfect setup, the maximum difference is less than 15 cm, and the standard deviation is about 3.5 cm. Visual inspection shows that coarse defects of the masonry, such as stone lacks or cavities, can be detected in the MSS point cloud, while smaller details, e.g. damaged joints, are harder to notice.

  14. Calibration of profile laser scanner with conical shape modification for autonomous mapping system

    NASA Astrophysics Data System (ADS)

    Koska, Bronislav

    2013-04-01

    Unmanned aerial mapping is becoming more and more popular in the last years, mostly because of advances in 3D reconstruction from images and its price affordability. The results of 3D reconstruction from images coming close to results of laser scanning in the resolution and accuracy point of view in some cases. However, mobile laser scanning still have advantages in reliability and easiness of measured data processing. That's why we have chosen an airship as a carrier capable to carry laser scanning unit. Most of the laser scanner used in mobile mapping works in profiler (2D, plane) mode. We decided to modify laser scanner Sick LD-LRS1000 for scanning in conical shape mode, because of its favorable properties. The realization of the modification is described in the paper.

  15. Shape measurement by a multi-view methodology based on the remote tracking of a 3D optical scanner

    NASA Astrophysics Data System (ADS)

    Barone, Sandro; Paoli, Alessandro; Viviano Razionale, Armando

    2012-03-01

    Full field optical techniques can be reliably used for 3D measurements of complex shapes by multi-view processes, which require the computation of transformation parameters relating different views into a common reference system. Although, several multi-view approaches have been proposed, the alignment process is still the crucial step of a shape reconstruction. In this paper, a methodology to automatically align 3D views has been developed by integrating a stereo vision system and a full field optical scanner. In particular, the stereo vision system is used to remotely track the optical scanner within a working volume. The tracking system uses stereo images to detect the 3D coordinates of retro-reflective infrared markers rigidly connected to the scanner. Stereo correspondences are established by a robust methodology based on combining the epipolar geometry with an image spatial transformation constraint. The proposed methodology has been validated by experimental tests regarding both the evaluation of the measurement accuracy and the 3D reconstruction of an industrial shape.

  16. Laser scanner ophthalmoscope with free selectable wavelength

    NASA Astrophysics Data System (ADS)

    Schweitzer, Dietrich; Kalve, B.; Leistritz, Lutz; Scibor, Mateusz; Hammer, Martin

    1996-12-01

    Multispectral images can provide useful information for objective diagnosis, control of the effect of therapy and for a patient-specific optimization of therapy regime in ophthalmology. Laser scanner systems have the advantage of a high radiation power also in case of small spectral bandwidth. Additionally, the flying spot principle reduces the irradiation of the patient. Commercial laser scanner ophthalmoscopes (LSO) are developed till now only for qualitative, visual interpretation. Maximal four fixed wavelengths are available with a stabilized radiation power. Using the spectral properties of fundus pigments like xanthophyll, rhodopsin or of pathological alterations, e.g. hard exudates, its optical density or local distribution can be determined in this way before and after therapy. As also three wavelengths can be chosen which are best suited for determination of oxygen saturation (OS) in the blood, the validity of the 3-(lambda) -method for 2D calculation of OS can be tested. These investigations are first steps in functional diagnosis of the metabolism in the human ocular fundus.

  17. 3-D laser patterning process utilizing horizontal and vertical patterning

    DOEpatents

    Malba, Vincent; Bernhardt, Anthony F.

    2000-01-01

    A process which vastly improves the 3-D patterning capability of laser pantography (computer controlled laser direct-write patterning). The process uses commercially available electrodeposited photoresist (EDPR) to pattern 3-D surfaces. The EDPR covers the surface of a metal layer conformally, coating the vertical as well as horizontal surfaces. A laser pantograph then patterns the EDPR, which is subsequently developed in a standard, commercially available developer, leaving patterned trench areas in the EDPR. The metal layer thereunder is now exposed in the trench areas and masked in others, and thereafter can be etched to form the desired pattern (subtractive process), or can be plated with metal (additive process), followed by a resist stripping, and removal of the remaining field metal (additive process). This improved laser pantograph process is simpler, faster, move manufacturable, and requires no micro-machining.

  18. The 3D laser radar vision processor system

    NASA Technical Reports Server (NTRS)

    Sebok, T. M.

    1990-01-01

    Loral Defense Systems (LDS) developed a 3D Laser Radar Vision Processor system capable of detecting, classifying, and identifying small mobile targets as well as larger fixed targets using three dimensional laser radar imagery for use with a robotic type system. This processor system is designed to interface with the NASA Johnson Space Center in-house Extra Vehicular Activity (EVA) Retriever robot program and provide to it needed information so it can fetch and grasp targets in a space-type scenario.

  19. Integrated Electro-optical Laser-Beam Scanners

    NASA Technical Reports Server (NTRS)

    Boord, Warren T.

    1990-01-01

    Scanners using solid-state devices compact, consume little power, and have no moving parts. Integrated electro-optical laser scanner, in conjunction with external lens, points outgoing beam of light in any number of different directions, depending on number of upper electrodes. Offers beam-deflection angles larger than those of acousto-optic scanners. Proposed for such diverse applications as nonimpact laser printing, color imaging, ranging, barcode reading, and robotic vision.

  20. Laser Scanner Survey to Cultural Heritage Conservation and Restoration

    NASA Astrophysics Data System (ADS)

    Vacca, G.; Deidda, M.; Dessi, A.; Marras, M.

    2012-07-01

    Siviller Castle (XV century), situated in Villasor, a city near Cagliari (Sardinia, Italy) and the tower bell of Mores, near Sassari (Sardinia, Italy). The cultural sites were surveyed with laser scanner Focus 3D by Faro and to process clouds point we were used the JRC 3D Reconstructor software

  1. Rail Track Detection and Modelling in Mobile Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    Oude Elberink, S.; Khoshelham, K.; Arastounia, M.; Diaz Benito, D.

    2013-10-01

    We present a method for detecting and modelling rails in mobile laser scanner data. The detection is based on the properties of the rail tracks and contact wires such as relative height, linearity and relative position with respect to other objects. Points classified as rail track are used in a 3D modelling algorithm. The modelling is done by first fitting a parametric model of a rail piece to the points along each track, and estimating the position and orientation parameters of each piece model. For each position and orientation parameter a smooth low-order Fourier curve is interpolated. Using all interpolated parameters a mesh model of the rail is reconstructed. The method is explained using two areas from a dataset acquired by a LYNX mobile mapping system in a mountainous area. Residuals between railway laser points and 3D models are in the range of 2 cm. It is concluded that a curve fitting algorithm is essential to reliably and accurately model the rail tracks by using the knowledge that railways are following a continuous and smooth path.

  2. 3D imaging LADAR with linear array devices: laser, detector and ROIC

    NASA Astrophysics Data System (ADS)

    Kameyama, Shumpei; Imaki, Masaharu; Tamagawa, Yasuhisa; Akino, Yosuke; Hirai, Akihito; Ishimura, Eitaro; Hirano, Yoshihito

    2009-07-01

    This paper introduces the recent development of 3D imaging LADAR (LAser Detection And Ranging) in Mitsubishi Electric Corporation. The system consists of in-house-made key devices which are linear array: the laser, the detector and the ROIC (Read-Out Integrated Circuit). The laser transmitter is the high power and compact planar waveguide array laser at the wavelength of 1.5 micron. The detector array consists of the low excess noise Avalanche Photo Diode (APD) using the InAlAs multiplication layer. The analog ROIC array, which is fabricated in the SiGe- BiCMOS process, includes the Trans-Impedance Amplifiers (TIA), the peak intensity detectors, the Time-Of-Flight (TOF) detectors, and the multiplexers for read-out. This device has the feature in its detection ability for the small signal by optimizing the peak intensity detection circuit. By combining these devices with the one dimensional fast scanner, the real-time 3D range image can be obtained. After the explanations about the key devices, some 3D imaging results are demonstrated using the single element key devices. The imaging using the developed array devices is planned in the near future.

  3. Quality Assessment and Comparison of Smartphone and Leica C10 Laser Scanner Based Point Clouds

    NASA Astrophysics Data System (ADS)

    Sirmacek, Beril; Lindenbergh, Roderik; Wang, Jinhu

    2016-06-01

    3D urban models are valuable for urban map generation, environment monitoring, safety planning and educational purposes. For 3D measurement of urban structures, generally airborne laser scanning sensors or multi-view satellite images are used as a data source. However, close-range sensors (such as terrestrial laser scanners) and low cost cameras (which can generate point clouds based on photogrammetry) can provide denser sampling of 3D surface geometry. Unfortunately, terrestrial laser scanning sensors are expensive and trained persons are needed to use them for point cloud acquisition. A potential effective 3D modelling can be generated based on a low cost smartphone sensor. Herein, we show examples of using smartphone camera images to generate 3D models of urban structures. We compare a smartphone based 3D model of an example structure with a terrestrial laser scanning point cloud of the structure. This comparison gives us opportunity to discuss the differences in terms of geometrical correctness, as well as the advantages, disadvantages and limitations in data acquisition and processing. We also discuss how smartphone based point clouds can help to solve further problems with 3D urban model generation in a practical way. We show that terrestrial laser scanning point clouds which do not have color information can be colored using smartphones. The experiments, discussions and scientific findings might be insightful for the future studies in fast, easy and low-cost 3D urban model generation field.

  4. The use of a low-cost visible light 3D scanner to create virtual reality environment models of actors and objects

    NASA Astrophysics Data System (ADS)

    Straub, Jeremy

    2015-05-01

    A low-cost 3D scanner has been developed with a parts cost of approximately USD $5,000. This scanner uses visible light sensing to capture both structural as well as texture and color data of a subject. This paper discusses the use of this type of scanner to create 3D models for incorporation into a virtual reality environment. It describes the basic scanning process (which takes under a minute for a single scan), which can be repeated to collect multiple positions, if needed for actor model creation. The efficacy of visible light versus other scanner types is also discussed.

  5. Comparison of quasi-3D and full-3D laser wakefield PIC simulations using azimuthal mode decomposition

    NASA Astrophysics Data System (ADS)

    Dalichaouch, Thamine; Yu, Peicheng; Davidson, Asher; Mori, Warren; Vieira, Jorge; Fonseca, Ricardo

    2015-11-01

    Laser wakefield acceleration (LWFA) has attracted a lot of interest as a possible compact particle accelerator. However, 3D simulations of plasma-based accelerators are computationally intensive, sometimes taking millions of core hours on today's computers. A quasi-3D particle-In-cell (PIC) approach has been developed to take advantage of azimuthal symmetry in LWFA (and PWFA) simulations by using a particle-in-cell description in r-z and a Fourier description in φ. Quasi-3D simulations of LWFA are computationally more efficient and faster than Full-3D simulations because only first few azimuthal harmonics are needed to capture the physics of the problem. We have developed a cylindrical mode decomposition diagnostic for 3D Cartesian geometry simulations to analyze the agreement between full-3D and quasi-3D PIC simulations of laser and beam-plasma interactions. The diagnostic interpolates field data from Full-3D PIC simulations onto an irregular cylindrical grid (r , φ , z). A Fourier decomposition is then performed on the interpolated 3D simulation data along the azimuthal direction. This diagnostic has the added advantage of separating out the wakefields from the laser field. Preliminary results for this diagnostic of LWFA and PWFA simulations with symmetric and nearly symmetric spot sizes as well as of laser-plasma interactions using lasers with orbital angular momentum (higher order Laguerre-Gaussian modes) will be presented.

  6. Recent development of 3D imaging laser sensor in Mitsubishi Electric Corporation

    NASA Astrophysics Data System (ADS)

    Imaki, M.; Kotake, N.; Tsuji, H.; Hirai, A.; Kameyama, S.

    2013-09-01

    We have been developing 3-D imaging laser sensors for several years, because they can acquire the additional information of the scene, i.e. the range data. It enhances the potential to detect unwanted people and objects, the sensors can be utilized for applications such as safety control and security surveillance, and so forth. In this paper, we focus on two types of our sensors, which are high-frame-rate type and compact-type. To realize the high-frame-rate type system, we have developed two key devices: the linear array receiver which has 256 single InAlAs-APD detectors and the read-out IC (ROIC) array which is fabricated in SiGe-BiCMOS process, and they are connected electrically to each other. Each ROIC measures not only the intensity, but also the distance to the scene by high-speed analog signal processing. In addition, by scanning the mirror mechanically in perpendicular direction to the linear image receiver, we have realized the high speed operation, in which the frame rate is over 30 Hz and the number of pixels is 256 x 256. In the compact-type 3-D imaging laser sensor development, we have succeeded in downsizing the transmitter by scanning only the laser beam with a two-dimensional MEMS scanner. To obtain wide fieldof- view image, as well as the angle of the MEMS scanner, the receiving optical system and the large area receiver are needed. We have developed the large detecting area receiver that consists of 32 rectangular detectors, where the output signals of each detector are summed up. In this phase, our original circuit evaluates each signal level, removes the low-level signals, and sums them, in order to improve the signalto- noise ratio. In the following paper, we describe the system configurations and the recent experimental results of the two types of our 3-D imaging laser sensors.

  7. Miniaturized laser illumination module for 3D areal mapper

    NASA Astrophysics Data System (ADS)

    Gaynor, Edwin S.; Blase, W. Paul; Woodward, Kim G.

    1998-01-01

    We report progress towards a miniaturized laser illumination module (LIM) for illuminating objects with structured light for 3D imaging purposes. The module, when combined with an off-axis camera and a PC, will image volumes in near-real- time at a range-dependent resolution using 256 X 256 resolution elements. The miniaturized LIM comprises a red laser diode source, a hologram, a spatial light modulator and a projection lens.We present optical and electronic design features of the device in terms of constraints on size and manufacturability. The miniature LIM can be applied to diverse 3D imaging problems to include industrial reverse engineering and inspection and medical diagnostics and prosthetics design.

  8. 3-D laser radar simulation for autonomous spacecraft landing

    NASA Technical Reports Server (NTRS)

    Reiley, Michael F.; Carmer, Dwayne C.; Pont, W. F.

    1991-01-01

    A sophisticated 3D laser radar sensor simulation, developed and applied to the task of autonomous hazard detection and avoidance, is presented. This simulation includes a backward ray trace to sensor subpixels, incoherent subpixel integration, range dependent noise, sensor point spread function effects, digitization noise, and AM-CW modulation. Specific sensor parameters, spacecraft lander trajectory, and terrain type have been selected to generate simulated sensor data.

  9. Electromagnetic induction sounding and 3D laser imaging in support of a Mars methane analogue mission

    NASA Astrophysics Data System (ADS)

    Boivin, A.; Lai, P.; Samson, C.; Cloutis, E.; Holladay, S.; Monteiro Santos, F. A.

    2013-07-01

    The Mars Methane Analogue Mission simulates a micro-rover mission whose purpose is to detect, analyze, and determine the source of methane emissions on the planet's surface. As part of this project, both an electromagnetic induction sounder (EMIS) and a high-resolution triangulation-based 3D laser scanner were tested at the Jeffrey open-pit asbestos mine to identify and characterize geological environments favourable to the occurrence of methane. The presence of serpentinite in the form of chrysotile (asbestos), magnesium carbonate, and iron oxyhydroxides make the mine a likely location for methane production. The EMIS clearly delineated the contacts between the two geological units found at the mine, peridotite and slate, which are separated by a shear zone. Both the peridotite and slate units have low and uniform apparent electrical conductivity and magnetic susceptibility, while the shear zone has much higher conductivity and susceptibility, with greater variability. The EMIS data were inverted and the resulting model captured lateral conductivity variations through the different bedrock geological units buried beneath a gravel road. The 3D point cloud data acquired by the laser scanner were fitted with triangular meshes where steeply dipping triangles were plotted in dark grey to accentuate discontinuities. The resulting images were further processed using Sobel edge detection to highlight networks of fractures which are potential pathways for methane seepage.

  10. Towards 3-D laser nano patterning in polymer optical materials

    NASA Astrophysics Data System (ADS)

    Scully, Patricia J.; Perrie, Walter

    2015-03-01

    Progress towards 3-D subsurface structuring of polymers using femtosecond lasers is presented. Highly localised refractive index changes can be generated deep in transparent optical polymers without pre doping for photosensitisation or post processing by annealing. Understanding the writing conditions surpasses the limitations of materials, dimensions and chemistry, to facilitate unique structures entirely formed by laser-polymeric interactions to overcome materials, dimensional, refractive index and wavelength constraints.. Numerical aperture, fluence, temporal pulselength, wavelength and incident polarisation are important parameters to be considered, in achieving the desired inscription. Non-linear aspects of multiphoton absorption, plasma generation, filamentation and effects of incident polarisation on the writing conditions will be presented.

  11. 3D laser traking of a particle in 3DFM

    NASA Astrophysics Data System (ADS)

    Desai, Kalpit; Welch, Gregory; Bishop, Gary; Taylor, Russell; Superfine, Richard

    2003-11-01

    The principal goal of 3D tracking in our home-built 3D Magnetic Force Microscope is to monitor movement of the particle with respect to laser beam waist and keep the particle at the center of laser beam. The sensory element is a Quadrant Photo Diode (QPD) which captures scattering of light caused by particle motion with bandwidth up to 40 KHz. XYZ translation stage is the driver element which moves particle back in the center of the laser with accuracy of couple of nanometers and with bandwidth up to 300 Hz. Since our particles vary in size, composition and shape, instead of using a priori model we use standard system identification techniques to have optimal approximation to the relationship between particle motion and QPD response. We have developed position feedback control system software that is capable of 3-dimensional tracking of beads that are attached to cilia on living cells which are beating at up to 15Hz. We have also modeled the control system of instrument to simulate performance of 3D particle tracking for different experimental conditions. Given operational level of nanometers, noise poses a great challenge for the tracking system. We propose to use stochastic control theory approaches to increase robustness of tracking.

  12. Drawing and Landscape Simulation for Japanese Garden by Using Terrestrial Laser Scanner

    NASA Astrophysics Data System (ADS)

    Kumazaki, R.; Kunii, Y.

    2015-05-01

    Recently, many laser scanners are applied for various measurement fields. This paper investigates that it was useful to use the terrestrial laser scanner in the field of landscape architecture and examined a usage in Japanese garden. As for the use of 3D point cloud data in the Japanese garden, it is the visual use such as the animations. Therefore, some applications of the 3D point cloud data was investigated that are as follows. Firstly, ortho image of the Japanese garden could be outputted for the 3D point cloud data. Secondly, contour lines of the Japanese garden also could be extracted, and drawing was became possible. Consequently, drawing of Japanese garden was realized more efficiency due to achievement of laborsaving. Moreover, operation of the measurement and drawing could be performed without technical skills, and any observers can be operated. Furthermore, 3D point cloud data could be edited, and some landscape simulations that extraction and placement of tree or some objects were became possible. As a result, it can be said that the terrestrial laser scanner will be applied in landscape architecture field more widely.

  13. Recent advances in dental optics - Part I: 3D intraoral scanners for restorative dentistry

    NASA Astrophysics Data System (ADS)

    Logozzo, Silvia; Zanetti, Elisabetta M.; Franceschini, Giordano; Kilpelä, Ari; Mäkynen, Anssi

    2014-03-01

    Intra-oral scanning technology is a very fast-growing field in dentistry since it responds to the need of an accurate three-dimensional mapping of the mouth, as required in a large number of procedures such as restorative dentistry and orthodontics. Nowadays, more than 10 intra-oral scanning devices for restorative dentistry have been developed all over the world even if only some of those devices are currently available on the market. All the existing intraoral scanners try to face with problems and disadvantages of traditional impression fabrication process and are based on different non-contact optical technologies and principles. The aim of this publication is to provide an extensive review of existing intraoral scanners for restorative dentistry evaluating their working principles, features and performances.

  14. Development, Calibration and Evaluation of a Portable and Direct Georeferenced Laser Scanning System for Kinematic 3D Mapping

    NASA Astrophysics Data System (ADS)

    Heinz, Erik; Eling, Christian; Wieland, Markus; Klingbeil, Lasse; Kuhlmann, Heiner

    2015-12-01

    In recent years, kinematic laser scanning has become increasingly popular because it offers many benefits compared to static laser scanning. The advantages include both saving of time in the georeferencing and a more favorable scanning geometry. Often mobile laser scanning systems are installed on wheeled platforms, which may not reach all parts of the object. Hence, there is an interest in the development of portable systems, which remain operational even in inaccessible areas. The development of such a portable laser scanning system is presented in this paper. It consists of a lightweight direct georeferencing unit for the position and attitude determination and a small low-cost 2D laser scanner. This setup provides advantages over existing portable systems that employ heavy and expensive 3D laser scanners in a profiling mode. A special emphasis is placed on the system calibration, i. e. the determination of the transformation between the coordinate frames of the direct georeferencing unit and the 2D laser scanner. To this end, a calibration field is used, which consists of differently orientated georeferenced planar surfaces, leading to estimates for the lever arms and boresight angles with an accuracy of mm and one-tenth of a degree. Finally, point clouds of the mobile laser scanning system are compared with georeferenced point clouds of a high-precision 3D laser scanner. Accordingly, the accuracy of the system is in the order of cm to dm. This is in good agreement with the expected accuracy, which has been derived from the error propagation of previously estimated variance components.

  15. Triangulation Based 3D Laser Imaging for Fracture Orientation Analysis

    NASA Astrophysics Data System (ADS)

    Mah, J.; Claire, S.; Steve, M.

    2009-05-01

    Laser imaging has recently been identified as a potential tool for rock mass characterization. This contribution focuses on the application of triangulation based, short-range laser imaging to determine fracture orientation and surface texture. This technology measures the distance to the target by triangulating the projected and reflected laser beams, and also records the reflection intensity. In this study, we acquired 3D laser images of rock faces using the Laser Camera System (LCS), a portable instrument developed by Neptec Design Group (Ottawa, Canada). The LCS uses an infrared laser beam and is immune to the lighting conditions. The maximum image resolution is 1024 x 1024 volumetric image elements. Depth resolution is 0.5 mm at 5 m. An above ground field trial was conducted at a blocky road cut with well defined joint sets (Kingston, Ontario). An underground field trial was conducted at the Inco 175 Ore body (Sudbury, Ontario) where images were acquired in the dark and the joint set features were more subtle. At each site, from a distance of 3 m away from the rock face, a grid of six images (approximately 1.6 m by 1.6 m) was acquired at maximum resolution with 20% overlap between adjacent images. This corresponds to a density of 40 image elements per square centimeter. Polyworks, a high density 3D visualization software tool, was used to align and merge the images into a single digital triangular mesh. The conventional method of determining fracture orientations is by manual measurement using a compass. In order to be accepted as a substitute for this method, the LCS should be capable of performing at least to the capabilities of manual measurements. To compare fracture orientation estimates derived from the 3D laser images to manual measurements, 160 inclinometer readings were taken at the above ground site. Three prominent joint sets (strike/dip: 236/09, 321/89, 325/01) were identified by plotting the joint poles on a stereonet. Underground, two main joint

  16. Multi-view alignment with database of features for an improved usage of high-end 3D scanners

    NASA Astrophysics Data System (ADS)

    Bonarrigo, Francesco; Signoroni, Alberto; Leonardi, Riccardo

    2012-12-01

    The usability of high-precision and high-resolution 3D scanners is of crucial importance due to the increasing demand of 3D data in both professional and general-purpose applications. Simplified, intuitive and rapid object modeling requires effective and automated alignment pipelines capable to trace back each independently acquired range image of the scanned object into a common reference system. To this end, we propose a reliable and fast feature-based multiple-view alignment pipeline that allows interactive registration of multiple views according to an unchained acquisition procedure. A robust alignment of each new view is estimated with respect to the previously aligned data through fast extraction, representation and matching of feature points detected in overlapping areas from different views. The proposed pipeline guarantees a highly reliable alignment of dense range image datasets on a variety of objects in few seconds per million of points.

  17. Pavement cracking measurements using 3D laser-scan images

    NASA Astrophysics Data System (ADS)

    Ouyang, W.; Xu, B.

    2013-10-01

    Pavement condition surveying is vital for pavement maintenance programs that ensure ride quality and traffic safety. This paper first introduces an automated pavement inspection system which uses a three-dimensional (3D) camera and a structured laser light to acquire dense transverse profiles of a pavement lane surface when it carries a moving vehicle. After the calibration, the 3D system can yield a depth resolution of 0.5 mm and a transverse resolution of 1.56 mm pixel-1 at 1.4 m camera height from the ground. The scanning rate of the camera can be set to its maximum at 5000 lines s-1, allowing the density of scanned profiles to vary with the vehicle's speed. The paper then illustrates the algorithms that utilize 3D information to detect pavement distress, such as transverse, longitudinal and alligator cracking, and presents the field tests on the system's repeatability when scanning a sample pavement in multiple runs at the same vehicle speed, at different vehicle speeds and under different weather conditions. The results show that this dedicated 3D system can capture accurate pavement images that detail surface distress, and obtain consistent crack measurements in repeated tests and under different driving and lighting conditions.

  18. 3D sensor for indirect ranging with pulsed laser source

    NASA Astrophysics Data System (ADS)

    Bronzi, D.; Bellisai, S.; Villa, F.; Scarcella, C.; Bahgat Shehata, A.; Tosi, A.; Padovini, G.; Zappa, F.; Tisa, S.; Durini, D.; Weyers, S.; Brockherde, W.

    2012-10-01

    The growing interest for fast, compact and cost-effective 3D ranging imagers for automotive applications has prompted to explore many different techniques for 3D imaging and to develop new system for this propose. CMOS imagers that exploit phase-resolved techniques provide accurate 3D ranging with no complex optics and are rugged and costeffective. Phase-resolved techniques indirectly measure the round-trip return of the light emitted by a laser and backscattered from a distant target, computing the phase delay between the modulated light and the detected signal. Singlephoton detectors, with their high sensitivity, allow to actively illuminate the scene with a low power excitation (less than 10W with diffused daylight illumination). We report on a 4x4 array of CMOS SPAD (Single Photon Avalanche Diodes) designed in a high-voltage 0.35 μm CMOS technology, for pulsed modulation, in which each pixel computes the phase difference between the laser and the reflected pulse. Each pixel comprises a high-performance 30 μm diameter SPAD, an analog quenching circuit, two 9 bit up-down counters and memories to store data during the readout. The first counter counts the photons detected by the SPAD in a time window synchronous with the laser pulse and integrates the whole echoed signal. The second counter accumulates the number of photon detected in a window shifted with respect to the laser pulse, and acquires only a portion of the reflected signal. The array is readout with a global shutter architecture, using a 100 MHz clock; the maximal frame rate is 3 Mframe/s.

  19. Development of a mixed pixel filter for improved dimension estimation using AMCW laser scanner

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Sohn, Hoon; Cheng, Jack C. P.

    2016-09-01

    Accurate dimension estimation is desired in many fields, but the traditional dimension estimation methods are time-consuming and labor-intensive. In the recent decades, 3D laser scanners have become popular for dimension estimation due to their high measurement speed and accuracy. Nonetheless, scan data obtained by amplitude-modulated continuous-wave (AMCW) laser scanners suffer from erroneous data called mixed pixels, which can influence the accuracy of dimension estimation. This study develops a mixed pixel filter for improved dimension estimation using AMCW laser scanners. The distance measurement of mixed pixels is firstly formulated based on the working principle of laser scanners. Then, a mixed pixel filter that can minimize the classification errors between valid points and mixed pixels is developed. Validation experiments were conducted to verify the formulation of the distance measurement of mixed pixels and to examine the performance of the proposed mixed pixel filter. Experimental results show that, for a specimen with dimensions of 840 mm × 300 mm, the overall errors of the dimensions estimated after applying the proposed filter are 1.9 mm and 1.0 mm for two different scanning resolutions, respectively. These errors are much smaller than the errors (4.8 mm and 3.5 mm) obtained by the scanner's built-in filter.

  20. 3D optical two-mirror scanner with focus-tunable lens.

    PubMed

    Pokorny, Petr; Miks, Antonin

    2015-08-01

    The paper presents formulas for a ray tracing in the optical system of two-mirror optical scanner with a focus-tunable lens. Furthermore, equations for the calculation of focal length which ensure focusing of a beam in the desired point in a detection plane are derived. The uncertainty description of such focal length follows as well. The chosen vector approach is general; therefore, the application of formulas in various configurations of the optical systems is possible. In the example situation, the authors derived formulas for mirrors' rotations and the focal length depending on the position of the point in the detection plane. PMID:26368115

  1. Using mid-range laser scanners to digitize cultural-heritage sites.

    PubMed

    Spring, Adam P; Peters, Caradoc; Minns, Tom

    2010-01-01

    Here, we explore new, more accessible ways of modeling 3D data sets that both professionals and amateurs can employ in areas such as architecture, forensics, geotechnics, cultural heritage, and even hobbyist modeling. To support our arguments, we present images from a recent case study in digital preservation of cultural heritage using a mid-range laser scanner. Our appreciation of the increasing variety of methods for capturing 3D spatial data inspired our research. Available methods include photogrammetry, airborne lidar, sonar, total stations (a combined electronic and optical survey instrument), and midand close-range scanning.1 They all can produce point clouds of varying density. In our case study, the point cloud produced by a mid-range scanner demonstrates how open source software can make modeling and disseminating data easier. Normally, researchers would model this data using expensive specialized software, and the data wouldn't extend beyond the laser-scanning community. PMID:20650714

  2. Ultra-wide-band 3D microwave imaging scanner for the detection of concealed weapons

    NASA Astrophysics Data System (ADS)

    Rezgui, Nacer-Ddine; Andrews, David A.; Bowring, Nicholas J.

    2015-10-01

    The threat of concealed weapons, explosives and contraband in footwear, bags and suitcases has led to the development of new devices, which can be deployed for security screening. To address known deficiencies of metal detectors and x-rays, an UWB 3D microwave imaging scanning apparatus using FMCW stepped frequency working in the K and Q bands and with a planar scanning geometry based on an x y stage, has been developed to screen suspicious luggage and footwear. To obtain microwave images of the concealed weapons, the targets are placed above the platform and the single transceiver horn antenna attached to the x y stage is moved mechanically to perform a raster scan to create a 2D synthetic aperture array. The S11 reflection signal of the transmitted sweep frequency from the target is acquired by a VNA in synchronism with each position step. To enhance and filter from clutter and noise the raw data and to obtain the 2D and 3D microwave images of the concealed weapons or explosives, data processing techniques are applied to the acquired signals. These techniques include background subtraction, Inverse Fast Fourier Transform (IFFT), thresholding, filtering by gating and windowing and deconvolving with the transfer function of the system using a reference target. To focus the 3D reconstructed microwave image of the target in range and across the x y aperture without using focusing elements, 3D Synthetic Aperture Radar (SAR) techniques are applied to the post-processed data. The K and Q bands, between 15 to 40 GHz, show good transmission through clothing and dielectric materials found in luggage and footwear. A description of the system, algorithms and some results with replica guns and a comparison of microwave images obtained by IFFT, 2D and 3D SAR techniques are presented.

  3. An Automatic Procedure for Combining Digital Images and Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    Moussa, W.; Abdel-Wahab, M.; Fritsch, D.

    2012-07-01

    Besides improving both the geometry and the visual quality of the model, the integration of close-range photogrammetry and terrestrial laser scanning techniques directs at filling gaps in laser scanner point clouds to avoid modeling errors, reconstructing more details in higher resolution and recovering simple structures with less geometric details. Thus, within this paper a flexible approach for the automatic combination of digital images and laser scanner data is presented. Our approach comprises two methods for data fusion. The first method starts by a marker-free registration of digital images based on a point-based environment model (PEM) of a scene which stores the 3D laser scanner point clouds associated with intensity and RGB values. The PEM allows the extraction of accurate control information for the direct computation of absolute camera orientations with redundant information by means of accurate space resection methods. In order to use the computed relations between the digital images and the laser scanner data, an extended Helmert (seven-parameter) transformation is introduced and its parameters are estimated. Precedent to that, in the second method, the local relative orientation parameters of the camera images are calculated by means of an optimized Structure and Motion (SaM) reconstruction method. Then, using the determined transformation parameters results in having absolute oriented images in relation to the laser scanner data. With the resulting absolute orientations we have employed robust dense image reconstruction algorithms to create oriented dense image point clouds, which are automatically combined with the laser scanner data to form a complete detailed representation of a scene. Examples of different data sets are shown and experimental results demonstrate the effectiveness of the presented procedures.

  4. Sensor modeling, self-calibration and accuracy testing of panoramic cameras and laser scanners

    NASA Astrophysics Data System (ADS)

    Amiri Parian, Jafar; Gruen, Armin

    2010-01-01

    Terrestrial Linear Array CCD-based panoramic cameras have been used for purely imaging purposes, but they also have a high potential for use in high accuracy measurement applications. The imaging geometry and the high information content of those images make them suitable candidates for quantitative image analysis. For that a particular sensor model has to be established and the inherent accuracy potential has to be investigated. We developed a sensor model for terrestrial Linear Array-based panoramic cameras by means of a modified bundle adjustment with additional parameters, which models substantial deviations of a real camera from the ideal one. We used 3D straight-line information in addition to tie points to conduct a full calibration and orientation without control point information. Due to the similarity of the operation of laser scanners to panoramic cameras the sensor model of the panoramic cameras was extended for the self-calibration of laser scanners. We present the joint sensor model for panoramic cameras and laser scanners and the results of self-calibration, which indicate a subpixel accuracy level for such highly dynamic systems. Finally we demonstrate the systems' accuracy of two typical panoramic cameras in 3D point positioning, using both a minimal number of control points and a free network adjustment. With these new panoramic imaging devices we have additional powerful sensors for image recording and efficient 3D object modeling.

  5. An omnidirectional 3D sensor with line laser scanning

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Gao, Bingtuan; Liu, Chuande; Wang, Peng; Gao, Shuanglei

    2016-09-01

    An active omnidirectional vision owns the advantages of the wide field of view (FOV) imaging, resulting in an entire 3D environment scene, which is promising in the field of robot navigation. However, the existing omnidirectional vision sensors based on line laser can measure points only located on the optical plane of the line laser beam, resulting in the low-resolution reconstruction. Whereas, to improve resolution, some other omnidirectional vision sensors with the capability of projecting 2D encode pattern from projector and curved mirror. However, the astigmatism property of curve mirror causes the low-accuracy reconstruction. To solve the above problems, a rotating polygon scanning mirror is used to scan the object in the vertical direction so that an entire profile of the observed scene can be obtained at high accuracy, without of astigmatism phenomenon. Then, the proposed method is calibrated by a conventional 2D checkerboard plate. The experimental results show that the measurement error of the 3D omnidirectional sensor is approximately 1 mm. Moreover, the reconstruction of objects with different shapes based on the developed sensor is also verified.

  6. 3D nanotube-based composites produced by laser irradiation

    SciTech Connect

    Ageeva, S A; Bobrinetskii, I I; Nevolin, Vladimir K; Podgaetskii, Vitalii M; Selishchev, S V; Simunin, M M; Konov, Vitalii I; Savranskii, V V; Ponomareva, O V

    2009-04-30

    3D nanocomposites have been fabricated through self-assembly under near-IR cw laser irradiation, using four types of multiwalled and single-walled carbon nanotubes produced by chemical vapour deposition, disproportionation on Fe clusters and cathode sputtering in an inert gas. The composites were prepared by laser irradiation of aqueous solutions of bovine serum albumin until the solvent was evaporated off and a homogeneous black material was obtained: modified albumin reinforced with nanotubes. The consistency of the composites ranged from paste-like to glass-like. Atomic force microscopy was used to study the surface morphology of the nanomaterials. The nanocomposites had a 3D quasi-periodic structure formed by almost spherical or toroidal particles 200-500 nm in diameter and 30-40 nm in visible height. Their inner, quasi-periodic structure was occasionally seen through surface microfractures. The density and hardness of the nanocomposites exceed those of microcrystalline albumin powder by 20% and by a factor of 3-5, respectively. (nanostructures)

  7. Portable and accurate 3D scanner for breast implant design and reconstructive plastic surgery

    NASA Astrophysics Data System (ADS)

    Rigotti, Camilla; Borghese, Nunzio A.; Ferrari, Stefano; Baroni, Guido; Ferrigno, Giancarlo

    1998-06-01

    In order to evaluate the proper breast implant, the surgeon relies on a standard set of measurements manually taken on the subject. This approach does not allow to obtain an accurate reconstruction of the breast shape and asymmetries can easily arise after surgery. The purpose of this work is to present a method which can help the surgeon in the choice of the shape and dimensions of a prosthesis allowing for a perfect symmetry between the prosthesis and the controlateral breast and can be used as a 3D visual feedback in plastic surgery.

  8. Analysis of main parameters affecting substrate/mortar contact area through tridimensional laser scanner.

    PubMed

    Stolz, Carina M; Masuero, Angela B

    2015-10-01

    This study assesses the influence of the granulometric composition of sand, application energy and the superficial tension of substrates on the contact area of rendering mortars. Three substrates with distinct wetting behaviors were selected and mortars were prepared with different sand compositions. Characterization tests were performed on fresh and hardened mortars, as well as the rheological characterization. Mortars were applied to substrates with two different energies. The interfacial area was then digitized with 3D scanner. Results show that variables are all of influence on the interfacial contact in the development area. Furthermore, 3D laser scanning proved to be a good method to contact area measurement. PMID:26046982

  9. Assessment of next-best-view algorithms performance with various 3D scanners and manipulator

    NASA Astrophysics Data System (ADS)

    Karaszewski, M.; Adamczyk, M.; Sitnik, R.

    2016-09-01

    The problem of calculating three dimensional (3D) sensor position (and orientation) during the digitization of real-world objects (called next best view planning or NBV) has been an active topic of research for over 20 years. While many solutions have been developed, it is hard to compare their quality based only on the exemplary results presented in papers. We implemented 13 of the most popular NBV algorithms and evaluated their performance by digitizing five objects of various properties, using three measurement heads with different working volumes mounted on a 6-axis robot with a rotating table for placing objects. The results obtained for the 13 algorithms were then compared based on four criteria: the number of directional measurements, digitization time, total positioning distance, and surface coverage required to digitize test objects with available measurement heads.

  10. Perspective Intensity Images for Co-Registration of Terrestrial Laser Scanner and Digital Camera

    NASA Astrophysics Data System (ADS)

    Liang, Yubin; Qiu, Yan; Cui, Tiejun

    2016-06-01

    Co-registration of terrestrial laser scanner and digital camera has been an important topic of research, since reconstruction of visually appealing and measurable models of the scanned objects can be achieved by using both point clouds and digital images. This paper presents an approach for co-registration of terrestrial laser scanner and digital camera. A perspective intensity image of the point cloud is firstly generated by using the collinearity equation. Then corner points are extracted from the generated perspective intensity image and the camera image. The fundamental matrix F is then estimated using several interactively selected tie points and used to obtain more matches with RANSAC. The 3D coordinates of all the matched tie points are directly obtained or estimated using the least squares method. The robustness and effectiveness of the presented methodology is demonstrated by the experimental results. Methods presented in this work may also be used for automatic registration of terrestrial laser scanning point clouds.

  11. Multimodal photoacoustic and optical coherence tomography scanner using an all optical detection scheme for 3D morphological skin imaging

    PubMed Central

    Zhang, Edward Z.; Povazay, Boris; Laufer, Jan; Alex, Aneesh; Hofer, Bernd; Pedley, Barbara; Glittenberg, Carl; Treeby, Bradley; Cox, Ben; Beard, Paul; Drexler, Wolfgang

    2011-01-01

    A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm2. The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather than 829-870 nm) and by operating in the tomographic rather than the optical resolution mode of photoacoustic imaging. Three-dimensional in vivo images of the vasculature and the surrounding tissue micro-morphology in murine and human skin were acquired. These studies demonstrated the complementary contrast and tissue information provided by each modality for high-resolution 3D imaging of vascular structures to depths of up to 5 mm. Potential applications include characterizing skin conditions such as tumors, vascular lesions, soft tissue damage such as burns and wounds, inflammatory conditions such as dermatitis and other superficial tissue abnormalities. PMID:21833358

  12. 3D-Laser-Scanning Technique Applied to Bulk Density Measurements of Apollo Lunar Samples

    NASA Technical Reports Server (NTRS)

    Macke, R. J.; Kent, J. J.; Kiefer, W. S.; Britt, D. T.

    2015-01-01

    In order to better interpret gravimetric data from orbiters such as GRAIL and LRO to understand the subsurface composition and structure of the lunar crust, it is import to have a reliable database of the density and porosity of lunar materials. To this end, we have been surveying these physical properties in both lunar meteorites and Apollo lunar samples. To measure porosity, both grain density and bulk density are required. For bulk density, our group has historically utilized sub-mm bead immersion techniques extensively, though several factors have made this technique problematic for our work with Apollo samples. Samples allocated for measurement are often smaller than optimal for the technique, leading to large error bars. Also, for some samples we were required to use pure alumina beads instead of our usual glass beads. The alumina beads were subject to undesirable static effects, producing unreliable results. Other investigators have tested the use of 3d laser scanners on meteorites for measuring bulk volumes. Early work, though promising, was plagued with difficulties including poor response on dark or reflective surfaces, difficulty reproducing sharp edges, and large processing time for producing shape models. Due to progress in technology, however, laser scanners have improved considerably in recent years. We tested this technique on 27 lunar samples in the Apollo collection using a scanner at NASA Johnson Space Center. We found it to be reliable and more precise than beads, with the added benefit that it involves no direct contact with the sample, enabling the study of particularly friable samples for which bead immersion is not possible

  13. Terrestrial Laser Scanner for Monitoring the Deformations and the Damages of Buildings

    NASA Astrophysics Data System (ADS)

    Vacca, G.; Mistretta, F.; Stochino, F.; Dessi, A.

    2016-06-01

    scanner provides the ability to detect the geometric 3D model of a building without any physical contact with the structure. Knowledge of the 3D model will give the opportunity to study the deformation and quantify the damages. Three case studies are presented relating to damaged and/or unsafe buildings: Sivillier Castle (Villasor - Sardinia- Italy), the Bell Tower of Mores (Sardinia-Italy) and industrial building (Cagliari - Italy). The first two cases concern buildings of historical and architectural importance that present a state of compromised conservation; the last, an industrial building compromised by fire. In all cases, a laser scanner survey was carried out that not only provided valuable information but also highlighted structural metric deformation and degradation.

  14. Feasibility study of 3D cardiac imaging using a portable conebeam scanner

    NASA Astrophysics Data System (ADS)

    Petrov, Ivailo; Helm, Patrick A.; Drangova, Maria

    2012-03-01

    While the Medtronic O-arm was developed for image-guidance applications during orthopedic procedures, it has potential to assist in cardiac surgical and electrophysiological applications; the purpose of this study was to evaluate the feasibility of using a mobile conebeam imaging system (O-arm) for gated cardiac imaging. In an in vivo study (two pigs), projection data from four independently acquired breath-held scans were combined to obtain cardiac gated 3D images. Projection images were acquired during the infusion of contrast agent and while tracking the ECG. Both standard and high-definition modes of the O-arm were evaluated. Projection data were retrospectively combined to generate images corresponding to systole and diastole; different acceptance windows were investigated. The contrast to noise ratio (CNR) between blood and myocardium was compared for the different gating strategies. Gated cardiac images were successfully reconstructed with as few as two scans combined (CNR = 2.5) and a window of 200 ms. Improved image quality was achieved when selecting views based on the minimum time from the selected phase point in the cardiac cycle, rather than a fixed window; in this case the effective temporal window increased to 475 ms for two scans. The O-arm has the potential to be used as a mobile cardiac imaging system, capable of three-dimensional imaging.

  15. A rigorous cylinder-based self-calibration approach for terrestrial laser scanners

    NASA Astrophysics Data System (ADS)

    Chan, Ting On; Lichti, Derek D.; Belton, David

    2015-01-01

    Existing self-calibration methods for terrestrial laser scanners are predominantly point-based and plane-based. In this paper, we present a new cylinder-based self-calibration method with its variants for several scanners having different architectures and scanning mechanisms. The method not only increases the flexibility of in situ self-calibration, but also its rigor because of reduced functional dependencies between adjustment parameters. Based on the analysis of linear dependencies between columns of the design matrices for both the cylindrical and planar models, it is shown that using the vertical cylindrical model is advantageous over using the planar model as some high linear dependencies can be avoided. The proposed method and its variants were first applied to two simulated datasets, to compare their effectiveness, and then to three real datasets captured by three different types of scanners are presented: a Faro Focus 3D (a phase-based panoramic scanner); a Velodyne HDL-32E (a pulse-based multi spinning beam scanner); and a Leica ScanStation C10 (a dual operating-mode scanner). The experimental results show that the proposed method can properly estimate the additional parameters with high precision. More importantly, no high correlations were found between the additional parameters and other parameters when the network configuration is strong. The overall results indicate that the proposed calibration method is rigorous and flexible.

  16. 3-D laser anemometer measurements in a labyrinth seal

    NASA Technical Reports Server (NTRS)

    Morrison, G. L.; Tatterson, G. B.; Johnson, M. C.

    1988-01-01

    The flow field inside a seven cavity labyrinth seal with a 0.00127 m clearance was measured using a 3-D laser Doppler anemometer system. Through the use of this system, the mean velocity vector and the entire Reynolds stress tensor distributions were measured for the first, third, fifth, and seventh cavities of the seal. There was one large recirculation region present in the cavity for the flow condition tested, Re = 28,000 and Ta = 7,000. The axial and radial mean velocities as well as all of the Reynolds stress term became cavity independent by the third cavity. The azimuthal mean velocity varied from cavity to cavity with its magnitude increasing as the flow progressed downstream.

  17. Voxel Based Representation of Full-Waveform Airborne Laser Scanner Data for Forestry Applications

    NASA Astrophysics Data System (ADS)

    Stelling, N.; Richter, K.

    2016-06-01

    The advantages of using airborne full-waveform laser scanner data in forest applications, e.g. for the description of the vertical vegetation structure or accurate biomass estimation, have been emphasized in many publications. To exploit the full potential offered by airborne full-waveform laser scanning data, the development of voxel based methods for data analysis is essential. In contrast to existing approaches based on the extraction of discrete 3D points by a Gaussian decomposition, it is very promising to derive the voxel attributes from the digitised waveform directly. For this purpose, the waveform data have to be transferred into a 3D voxel representation. This requires a series of radiometric and geometric transformations of the raw full-waveform laser scanner data. Thus, the paper deals with the geometric aspects and describes a processing chain from the raw waveform data to an attenuationcorrected volumetric forest stand reconstruction. The integration of attenuation-corrected waveform data into the voxel space is realised with an efficient parametric voxel traversal method operating on an octree data structure. The voxel attributes are derived from the amplitudes of the attenuation-corrected waveforms. Additionally, a new 3D filtering approach is presented to eliminate non-object voxel. Applying these methods to real full-waveform laser scanning data, a voxel based representation of a spruce was generated combining three flight strips from different viewing directions.

  18. Time Efficient 3D Radial UTE Sampling with Fully Automatic Delay Compensation on a Clinical 3T MR Scanner

    PubMed Central

    Reichenbach, Jürgen R.

    2016-01-01

    This work’s aim was to minimize the acquisition time of a radial 3D ultra-short echo-time (UTE) sequence and to provide fully automated, gradient delay compensated, and therefore artifact free, reconstruction. The radial 3D UTE sequence (echo time 60 μs) was implemented as single echo acquisition with center-out readouts and improved time efficient spoiling on a clinical 3T scanner without hardware modifications. To assess the sequence parameter dependent gradient delays each acquisition contained a quick calibration scan and utilized the phase of the readouts to detect the actual k-space center. This calibration scan does not require any user interaction. To evaluate the robustness of this automatic delay estimation phantom experiments were performed and 19 in vivo imaging data of the head, tibial cortical bone, feet and lung were acquired from 6 volunteers. As clinical application of this fast 3D UTE acquisition single breath-hold lung imaging is demonstrated. The proposed sequence allowed very short repetition times (TR~1ms), thus reducing total acquisition time. The proposed, fully automated k-phase based gradient delay calibration resulted in accurate delay estimations (difference to manually determined optimal delay −0.13 ± 0.45 μs) and allowed unsupervised reconstruction of high quality images for both phantom and in vivo data. The employed fast spoiling scheme efficiently suppressed artifacts caused by incorrectly refocused echoes. The sequence proved to be quite insensitive to motion, flow and susceptibility artifacts and provides oversampling protection against aliasing foldovers in all directions. Due to the short TR, acquisition times are attractive for a wide range of clinical applications. For short T2* mapping this sequence provides free choice of the second TE, usually within less scan time as a comparable dual echo UTE sequence. PMID:26975051

  19. Time Efficient 3D Radial UTE Sampling with Fully Automatic Delay Compensation on a Clinical 3T MR Scanner.

    PubMed

    Herrmann, Karl-Heinz; Krämer, Martin; Reichenbach, Jürgen R

    2016-01-01

    This work's aim was to minimize the acquisition time of a radial 3D ultra-short echo-time (UTE) sequence and to provide fully automated, gradient delay compensated, and therefore artifact free, reconstruction. The radial 3D UTE sequence (echo time 60 μs) was implemented as single echo acquisition with center-out readouts and improved time efficient spoiling on a clinical 3T scanner without hardware modifications. To assess the sequence parameter dependent gradient delays each acquisition contained a quick calibration scan and utilized the phase of the readouts to detect the actual k-space center. This calibration scan does not require any user interaction. To evaluate the robustness of this automatic delay estimation phantom experiments were performed and 19 in vivo imaging data of the head, tibial cortical bone, feet and lung were acquired from 6 volunteers. As clinical application of this fast 3D UTE acquisition single breath-hold lung imaging is demonstrated. The proposed sequence allowed very short repetition times (TR~1ms), thus reducing total acquisition time. The proposed, fully automated k-phase based gradient delay calibration resulted in accurate delay estimations (difference to manually determined optimal delay -0.13 ± 0.45 μs) and allowed unsupervised reconstruction of high quality images for both phantom and in vivo data. The employed fast spoiling scheme efficiently suppressed artifacts caused by incorrectly refocused echoes. The sequence proved to be quite insensitive to motion, flow and susceptibility artifacts and provides oversampling protection against aliasing foldovers in all directions. Due to the short TR, acquisition times are attractive for a wide range of clinical applications. For short T2* mapping this sequence provides free choice of the second TE, usually within less scan time as a comparable dual echo UTE sequence. PMID:26975051

  20. See-Through Imaging of Laser-Scanned 3d Cultural Heritage Objects Based on Stochastic Rendering of Large-Scale Point Clouds

    NASA Astrophysics Data System (ADS)

    Tanaka, S.; Hasegawa, K.; Okamoto, N.; Umegaki, R.; Wang, S.; Uemura, M.; Okamoto, A.; Koyamada, K.

    2016-06-01

    We propose a method for the precise 3D see-through imaging, or transparent visualization, of the large-scale and complex point clouds acquired via the laser scanning of 3D cultural heritage objects. Our method is based on a stochastic algorithm and directly uses the 3D points, which are acquired using a laser scanner, as the rendering primitives. This method achieves the correct depth feel without requiring depth sorting of the rendering primitives along the line of sight. Eliminating this need allows us to avoid long computation times when creating natural and precise 3D see-through views of laser-scanned cultural heritage objects. The opacity of each laser-scanned object is also flexibly controllable. For a laser-scanned point cloud consisting of more than 107 or 108 3D points, the pre-processing requires only a few minutes, and the rendering can be executed at interactive frame rates. Our method enables the creation of cumulative 3D see-through images of time-series laser-scanned data. It also offers the possibility of fused visualization for observing a laser-scanned object behind a transparent high-quality photographic image placed in the 3D scene. We demonstrate the effectiveness of our method by applying it to festival floats of high cultural value. These festival floats have complex outer and inner 3D structures and are suitable for see-through imaging.

  1. Optimization of 3D laser scanning speed by use of combined variable step

    NASA Astrophysics Data System (ADS)

    Garcia-Cruz, X. M.; Sergiyenko, O. Yu.; Tyrsa, Vera; Rivas-Lopez, M.; Hernandez-Balbuena, D.; Rodriguez-Quiñonez, J. C.; Basaca-Preciado, L. C.; Mercorelli, P.

    2014-03-01

    The problem of 3D TVS slow functioning caused by constant small scanning step becomes its solution in the presented research. It can be achieved by combined scanning step application for the fast search of n obstacles in unknown surroundings. Such a problem is of keynote importance in automatic robot navigation. To maintain a reasonable speed robots must detect dangerous obstacles as soon as possible, but all known scanners able to measure distances with sufficient accuracy are unable to do it in real time. So, the related technical task of the scanning with variable speed and precise digital mapping only for selected spatial sectors is under consideration. A wide range of simulations in MATLAB 7.12.0 of several variants of hypothetic scenes with variable n obstacles in each scene (including variation of shapes and sizes) and scanning with incremented angle value (0.6° up to 15°) is provided. The aim of such simulation was to detect which angular values of interval still permit getting the maximal information about obstacles without undesired time losses. Three of such local maximums were obtained in simulations and then rectified by application of neuronal network formalism (Levenberg-Marquradt Algorithm). The obtained results in its turn were applied to MET (Micro-Electro-mechanical Transmission) design for practical realization of variable combined step scanning on an experimental prototype of our previously known laser scanner.

  2. Automatic Method for Building Indoor Boundary Models from Dense Point Clouds Collected by Laser Scanners

    PubMed Central

    Valero, Enrique; Adán, Antonio; Cerrada, Carlos

    2012-01-01

    In this paper we present a method that automatically yields Boundary Representation Models (B-rep) for indoors after processing dense point clouds collected by laser scanners from key locations through an existing facility. Our objective is particularly focused on providing single models which contain the shape, location and relationship of primitive structural elements of inhabited scenarios such as walls, ceilings and floors. We propose a discretization of the space in order to accurately segment the 3D data and generate complete B-rep models of indoors in which faces, edges and vertices are coherently connected. The approach has been tested in real scenarios with data coming from laser scanners yielding promising results. We have deeply evaluated the results by analyzing how reliably these elements can be detected and how accurately they are modeled. PMID:23443369

  3. Application of 3D laser scanning technology in historical building preservation: a case study of a Chinese temple

    NASA Astrophysics Data System (ADS)

    Chang, Yu Min; Lu, Nien Hua; Wu, Tsung Chiang

    2005-06-01

    This study applies 3D Laser scanning technology to develop a high-precision measuring system for digital survey of historical building. It outperformed other methods in obtaining abundant high-precision measuring points and computing data instantly. In this study, the Pei-tien Temple, a Chinese Taoism temple in southern Taiwan famous for its highly intricate architecture and more than 300-year history, was adopted as the target to proof the high accuracy and efficiency of this system. By using French made MENSI GS-100 Laser Scanner, numerous measuring points were precisely plotted to present the plane map, vertical map and 3D map of the property. Accuracies of 0.1-1 mm in the digital data have consistently been achieved for the historical heritage measurement.

  4. Quality control loop for 3D laser beam cutting

    NASA Astrophysics Data System (ADS)

    Spitznagel, Juergen

    1996-08-01

    Existing systems for computer integrated manufacturing are based on the principle of the process chain: The product runs through different production sections as design, work planning and manufacturing in a sequential order. The data generated by a production sequence are transferred via interface to the following production sequence. These tightly-packed production sequences leave little scope for responding to quality deviations. This deficit is highlighted particularly in 3D laser cutting processes. In order to achieve an optimum machining result, a series of preliminary tests is required. Quality control loops play an important role in restricting the scope of necessary testing to a minimum. The represented control loop contains a CAD- system to design the workpiece, an offline-programming system to develop working strategies and NC/RC-programs as well as a shop-floor oriented tool to record quality data of the workpiece. The systems are coupled by an integrated product model. The control loop feeds quality data back to Operations Planning in the form of rules for processing strategies and technological data, so that the quality of the production process is enhanced. It is intended to supply optimum process parameters, so that the number of preliminary tests can be reduced. On the other hand the control loop contributes quality enhancement measures which serve as rules for the designers.

  5. Laser Scanner Tests For Single-Event Upsets

    NASA Technical Reports Server (NTRS)

    Kim, Quiesup; Soli, George A.; Schwartz, Harvey R.

    1992-01-01

    Microelectronic advanced laser scanner (MEALS) is opto/electro/mechanical apparatus for nondestructive testing of integrated memory circuits, logic circuits, and other microelectronic devices. Multipurpose diagnostic system used to determine ultrafast time response, leakage, latchup, and electrical overstress. Used to simulate some of effects of heavy ions accelerated to high energies to determine susceptibility of digital device to single-event upsets.

  6. The study of craniofacial growth patterns using 3D laser scanning and geometric morphometrics

    NASA Astrophysics Data System (ADS)

    Friess, Martin

    2006-02-01

    Throughout childhood, braincase and face grow at different rates and therefore exhibit variable proportions and positions relative to each other. Our understanding of the direction and magnitude of these growth patterns is crucial for many ergonomic applications and can be improved by advanced 3D morphometrics. The purpose of this study is to investigate this known growth allometry using 3D imaging techniques. The geometry of the head and face of 840 children, aged 2 to 19, was captured with a laser surface scanner and analyzed statistically. From each scan, 18 landmarks were extracted and registered using General Procrustes Analysis (GPA). GPA eliminates unwanted variation due to position, orientation and scale by applying a least-squares superimposition algorithm to individual landmark configurations. This approach provides the necessary normalization for the study of differences in size, shape, and their interaction (allometry). The results show that throughout adolescence, boys and girls follow a different growth trajectory, leading to marked differences not only in size but also in shape, most notably in relative proportions of the braincase. These differences can be observed during early childhood, but become most noticeable after the age of 13 years, when craniofacial growth in girls slows down significantly, whereas growth in boys continues for at least 3 more years.

  7. More About Laser Scanner Tests For Single-Event Upsets

    NASA Technical Reports Server (NTRS)

    Kim, Quiesup; Edmonds, Larry D.; Zoutendyk, John A.; Schwartz, Harvey R.

    1993-01-01

    Two reports describe preliminary theoretical and experimental studies based on method described in "Laser Scanner Tests For Single-Event Upsets" (NPO-18216). Laser-scan and heavy-ion data found correlated within factor of two. Method of testing for single-event upsets intended to overcome disadvantages of, complement, and/or substitute for more-expensive cyclotron-testing method, which does not provide spatial resolution.

  8. Registration of time of flight terrestrial laser scanner data for stop-and-go mode

    NASA Astrophysics Data System (ADS)

    Mohammed, H.; Alsubaie, N. M.; Elhabiby, M.; El-sheimy, N.

    2014-11-01

    Terrestrial Laser Scanners (TLS) are utilized through different data acquisition techniques such as Mobile Laser Scanning (MLS) and the output can be used in different applications such as 3D city modelling, cultural heritage documentations, oil and Gas as built, etc... In this research paper, we will investigate one of the modes of TLS on mobile mapping platform. Namely the Stop-and-Go (SAG) mode. Unlike the continuous mode, the Stop-and-Go mode does not require the use of IMU to estimate the TLS attitude and thus inturn it has an overall reduction in the system cost. Moreover, it decreases the time required for data processing in comparison with the continuous mode. For successful use of SAG mobile mapping in urban areas, it is preferred to use a long range time of flight laser scanner to cover long distances in each scan and minimize the registration error. The problem arise with Long range laser scanners is their low point cloud density. The low point cloud density affects the registration accuracy specially in monitoring applications. The point spacing between points is one of the issues facing the registration especially when the matching points are chosen manually. Since most of TLS nowadays are equipped with camera on-board we can utilize the camera to get an initial estimate of the registration parameters based on image matching. After having an initial approximation of the registration parameters we feed those parameters to the Iterative Closest Point algorithm to obtain more accurate registration result.

  9. Laser Scanner Reliefs of Selected Archeological Structures in the Submerged Baiae (naples)

    NASA Astrophysics Data System (ADS)

    Davidde Petriaggi, B.; Gomez de Ayala, G.

    2015-04-01

    In 2011 the ISCR (Rome), in the frame of the Project Restoring Underwater directed by Barbara Davidde Petriaggi, started to test Naumacos Laser Scann 1, designed by Gabriele Gomez de Ayala, in order to document the restoration of a room paved with opus sectile probably part of the Bath of Punta Epitaffio (Underwater Park of Baiae - Marine Protected Area, Naples). The experimentation conducted in Baiae by ISCR has shown the effectiveness of the Laser Scanner; this method also allowed to considerably reduce times and costs of underwater surveying. Moreover, the 3D relief obtained, has the characteristic of being geometrically (accuracy is sub-millimetric) and chromatically faithful to the reconstructed structure, as well as being exportable in various forms and usable in several contexts. From 2011 to 2013 the evolution of the instrument Naumacos Laser Scanner 3 was developed and tested in the restoration work of the Villa con ingresso a protiro, where three structures were documented in 3D (a paved with black and white mosaic decorated with hexagons and peltae, a very fragmentary black and white mosaic and a stone artefact. This paper shows the results of this documentation campaign and it underlines the prominent role in documentation and in museum display of Underwater Cultural Heritage played by the three-dimensional laser scanning survey. This technique also contributes to the increase of the value of scientific dissemination.

  10. Digital dental surface registration with laser scanner for orthodontics set-up planning

    NASA Astrophysics Data System (ADS)

    Alcaniz-Raya, Mariano L.; Albalat, Salvador E.; Grau Colomer, Vincente; Monserrat, Carlos A.

    1997-05-01

    We present an optical measuring system based on laser structured light suitable for its diary use in orthodontics clinics that fit four main requirements: (1) to avoid use of stone models, (2) to automatically discriminate geometric points belonging to teeth and gum, (3) to automatically calculate diagnostic parameters used by orthodontists, (4) to make use of low cost and easy to use technology for future commercial use. Proposed technique is based in the use of hydrocolloids mould used by orthodontists for stone model obtention. These mould of the inside of patient's mouth are composed of very fluent materials like alginate or hydrocolloids that reveal fine details of dental anatomy. Alginate mould are both very easy to obtain and very low costly. Once captured, alginate moulds are digitized by mean of a newly developed and patented 3D dental scanner. Developed scanner is based in the optical triangulation method based in the projection of a laser line on the alginate mould surface. Line deformation gives uncalibrated shape information. Relative linear movements of the mould with respect to the sensor head gives more sections thus obtaining a full 3D uncalibrated dentition model. Developed device makes use of redundant CCD in the sensor head and servocontrolled linear axis for mould movement. Last step is calibration to get a real and precise X, Y, Z image. All the process is done automatically. The scanner has been specially adapted for 3D dental anatomy capturing in order to fulfill specific requirements such as: scanning time, accuracy, security and correct acquisition of 'hidden points' in alginate mould. Measurement realized on phantoms with known geometry quite similar to dental anatomy present errors less than 0,1 mm. Scanning of global dental anatomy is 2 minutes, and generation of 3D graphics of dental cast takes approximately 30 seconds in a Pentium-based PC.

  11. Laser trepanning of CFRP with a scanner head for IR and UV lasers

    NASA Astrophysics Data System (ADS)

    Anzai, Kenji; Aoyama, Mitsuaki; Fujisaki, Akira; Miyato, Taizo; Kayahara, Takashi; Harada, Yoshihisa; Niino, Hiroyuki

    2014-03-01

    The dual beam of cw-350 W single-mode near-IR fiber laser and ns-pulsed-35 W UV laser were used in the experiments for cutting. The laser beam on the sample surface was scanned with a galvanometer scanner and focused with the f-theta lens of 400 mm focal length for IR and UV laser irradiations. A prototype remote scanner head for the multiple laser irradiations has been developed for a high-quality and high-speed laser processing of carbon fiber reinforced plastics (CFRP). In this paper, we report on the laser trepanning of circular patterns on CFRP.

  12. Increase of Readability and Accuracy of 3d Models Using Fusion of Close Range Photogrammetry and Laser Scanning

    NASA Astrophysics Data System (ADS)

    Gašparović, M.; Malarić, I.

    2012-07-01

    The development of laser scanning technology has opened a new page in geodesy and enabled an entirely new way of presenting data. Products obtained by the method of laser scanning are used in many sciences, as well as in archaeology. It should be noted that 3D models of archaeological artefacts obtained by laser scanning are fully measurable, written in 1:1 scale and have high accuracy. On the other hand, texture and RGB values of the surface of the object obtained by a laser scanner have lower resolution and poorer radiometric characteristics in relation to the textures captured with a digital camera. Scientific research and the goal of this paper are to increase the accuracy and readability of the 3D model with textures obtained with a digital camera. Laser scanning was performed with triangulation scanner of high accuracy, Vivid 9i (Konica Minolta), while for photogrammetric recording digital camera Nikon D90 with a lens of fixed focal length 20 mm, was used. It is important to stress that a posteriori accuracy score of the global registration of point clouds in the form of the standard deviation was ± 0.136 mm while the average distance was only ± 0.080 mm. Also research has proven that the quality projection texture model increases readability. Recording of archaeological artefacts and making their photorealistic 3D model greatly contributes to archaeology as a science, accelerates processing and reconstruction of the findings. It also allows the presentation of findings to the general public, not just to the experts.

  13. Evaluation of the ECAT EXACT HR{sup +} 3D PET scanner in {sup 15}O-water brain activation studies

    SciTech Connect

    Moreno-Cantu, J.J.; Thompson, C.J.; Zatorre, R.J.

    1996-12-31

    We evaluated the performance of the ECAT EXACT HR{sup +} 3D whole body PET scanner when employed to measure brain function using {sup 15}O-water-bolus activation protocols in single data acquisition sessions. Using vibrotactile and auditory stimuli as independent activation tasks, we studied the scanner`s performance under different imaging conditions in four healthy volunteers. Cerebral blood flow images were acquired from each volunteer using {sup 15}O-water-bolus injections of activity varying from 5 to 20mCi. Performance characteristics. The scanner`s dead time grew linearly with injected dose from 10% to 25%. Random events varied from 30% to 50% of the detected events. Scattered events were efficiently corrected at all doses. Noise-effective-count curves plateau at about 15mCi. One-session 12-injection bolus PET activation protocol. Using an acquisition protocol that accounts for the scanner`s performance and the practical aspects of imaging volunteers and patients in one session, we assessed the correlation between the statistical significance of activation foci and the dose per injection used The one-session protocol employs 12 bolus injections per subject. We present evidence suggesting that 15-20mCi is the optimal dose per injection to be used routinely in one-time scanning sessions.

  14. Large depth-of-view portable three-dimensional laser scanner and its segmental calibration for robot vision

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Guo, Yongkang; Zhu, Jianhua; Lin, Xiangdi; Xin, Yao; Duan, Kailiang; Tang, Qing

    2007-11-01

    A portable 3D laser scanning system has been designed and built for robot vision. By tilting the charge coupled device (CCD) plane of portable 3D scanning system according to the Scheimpflug condition, the depth-of-view is successfully extended from less than 40 to 100 mm. Based on the tilted camera model, the traditional two-step camera calibration method is modified by introducing the angle factor. Meanwhile, a novel segmental calibration approach, i.e., dividing the whole work range into two parts and calibrating, respectively, with corresponding system parameters, is proposed to effectively improve the measurement accuracy of the large depth-of-view 3D laser scanner. In the process of 3D reconstruction, different calibration parameters are used to transform the 2D coordinates into 3D coordinates according to the different positions of the image in the CCD plane, and the measurement accuracy of 60 μm is obtained experimentally. Finally, the experiment of scanning a lamina by the large depth-of-view portable 3D laser scanner used by an industrial robot IRB 4400 is also employed to demonstrate the effectiveness and high measurement accuracy of our scanning system.

  15. Performance evaluation of laser scanners through the atmosphere with adverse condition

    NASA Astrophysics Data System (ADS)

    Hespel, L.; Riviere, N.; Huet, T.; Tanguy, B.; Ceolato, R.

    2011-11-01

    Using laser imaging systems to represent 3-D scene becomes a referent prospective technology in the areas of guidance and navigation. Measurements with high spatial resolution for significant range can be achieved, even in degraded visibility conditions such as the Brown-White Out, rain, fog, sandstorms... Moreover, this technology is well suited for assisted perception tasks (access to 3D information) and obstacle detection (telemetry of small objects). For airborne applications, it is very complementary to conventional enhanced vision systems such as Forward Looking Infrared (FLIR) and millimeter wave radar to provide images of land in environments with limited visibility. It also offers a 3D mapping of land or a single location in relation to the environment, which means alone or coupled with others, can realign and secure real-time database of information used such in a synthetic vision system (SVS). The objective of the work is to assess the impact of degraded visibility conditions on the laser radiometric propagation of a 3D laser scanner as they directly influence the performance of the ladar system [1].

  16. Coordinates calibration method in a robotic remanufacturing measurement system based on linear laser scanner

    NASA Astrophysics Data System (ADS)

    Shen, C. D.; Zhu, S.; Li, C.; Liang, Y. Y.

    2009-07-01

    In robotic remanufacturing measurement system, the 3D laser scanner is arranged by the robot and the object scanned is mounted on a turntable. This paper deals with the method of calibrating the relationship between the scanner coordinate and the robot Tool0 and furthermore locating the center axis of the turntable. The data of Tool0 can be directly obtained denoting its relationship with the robot base coordinate. So, the new methods of coordinate's transformation are effectively developed. Moreover some motivated experiments and optimized programs are designed for realizing process stabilization and reliability. This paper detailed explains the basic algorithm theory, practical operation instructions, the experiment data analysis, and etc. Theory deduction and experiments show the new methods are reasonable and efficient.

  17. Permanent 3D laser scanning system for an active landslide in Gresten (Austria)

    NASA Astrophysics Data System (ADS)

    Canli, Ekrem; Höfle, Bernhard; Hämmerle, Martin; Benni, Thiebes; Glade, Thomas

    2015-04-01

    Terrestrial laser scanners (TLS) have widely been used for high spatial resolution data acquisition of topographic features and geomorphic analyses. Existing applications encompass different landslides including rockfall, translational or rotational landslides, debris flow, but also coastal cliff erosion, braided river evolution or river bank erosion. The main advantages of TLS are (a) the high spatial sampling density of XYZ-measurements (e.g. 1 point every 2-3 mm at 10 m distance), particularly in comparison with the low data density monitoring techniques such as GNSS or total stations, (b) the millimeter accuracy and precision of the range measurement to centimeter accuracy of the final DEM, and (c) the highly dense area-wide scanning that enables to look through vegetation and to measure bare ground. One of its main constraints is the temporal resolution of acquired data due to labor costs and time requirements for field campaigns. Thus, repetition measurements are generally performed only episodically. However, for an increased scientific understanding of the processes as well as for early warning purposes, we present a novel permanent 3D monitoring setup to increase the temporal resolution of TLS measurements. This accounts for different potential monitoring deliverables such as volumetric calculations, spatio-temporal movement patterns, predictions and even alerting. This system was installed at the active Salcher landslide in Gresten (Austria) that is situated in the transition zone of the Gresten Klippenbelt (Helvetic) and the Flyschzone (Penninic). The characteristic lithofacies are the Gresten Beds of Early Jurassic age that are covered by a sequence of marly and silty beds with intercalated sandy limestones. Permanent data acquisition can be implemented into our workflow with any long-range TLS system offering fully automated capturing. We utilize an Optech ILRIS-3D scanner. The time interval between two scans is currently set to 24 hours, but can be

  18. 3D laser gated viewing from a moving submarine platform

    NASA Astrophysics Data System (ADS)

    Christnacher, F.; Laurenzis, M.; Monnin, D.; Schmitt, G.; Metzger, Nicolas; Schertzer, Stéphane; Scholtz, T.

    2014-10-01

    Range-gated active imaging is a prominent technique for night vision, remote sensing or vision through obstacles (fog, smoke, camouflage netting…). Furthermore, range-gated imaging not only informs on the scene reflectance but also on the range for each pixel. In this paper, we discuss 3D imaging methods for underwater imaging applications. In this situation, it is particularly difficult to stabilize the imaging platform and these 3D reconstruction algorithms suffer from the motion between the different images in the recorded sequence. To overcome this drawback, we investigated a new method based on a combination between image registration by homography and 3D scene reconstruction through tomography or two-image technique. After stabilisation, the 3D reconstruction is achieved by using the two upper-mentioned techniques. In the different experimental examples given in this paper, a centimetric resolution could be achieved.

  19. Using quality metrics with laser range scanners

    NASA Astrophysics Data System (ADS)

    MacKinnon, David K.; Aitken, Victor; Blais, Francois

    2008-02-01

    We have developed a series of new quality metrics that are generalizable to a variety of laser range scanning systems, including those acquiring measurements in the mid-field. Moreover, these metrics can be integrated into either an automated scanning system, or a system that guides a minimally trained operator through the scanning process. In particular, we represent the quality of measurements with regard to aliasing and sampling density for mid-field measurements, two issues that have not been well addressed in contemporary literature. We also present a quality metric that addresses the issue of laser spot motion during sample acquisition. Finally, we take into account the interaction between measurement resolution and measurement uncertainty where necessary. These metrics are presented within the context of an adaptive scanning system in which quality metrics are used to minimize the number of measurements obtained during the acquisition of a single range image.

  20. Robust object segmentation using a multi-layer laser scanner.

    PubMed

    Kim, Beomseong; Choi, Baehoon; Yoo, Minkyun; Kim, Hyunju; Kim, Euntai

    2014-01-01

    The major problem in an advanced driver assistance system (ADAS) is the proper use of sensor measurements and recognition of the surrounding environment. To this end, there are several types of sensors to consider, one of which is the laser scanner. In this paper, we propose a method to segment the measurement of the surrounding environment as obtained by a multi-layer laser scanner. In the segmentation, a full set of measurements is decomposed into several segments, each representing a single object. Sometimes a ghost is detected due to the ground or fog, and the ghost has to be eliminated to ensure the stability of the system. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments show that the proposed method demonstrates good performance in many real-life situations. PMID:25356645

  1. Robust Object Segmentation Using a Multi-Layer Laser Scanner

    PubMed Central

    Kim, Beomseong; Choi, Baehoon; Yoo, Minkyun; Kim, Hyunju; Kim, Euntai

    2014-01-01

    The major problem in an advanced driver assistance system (ADAS) is the proper use of sensor measurements and recognition of the surrounding environment. To this end, there are several types of sensors to consider, one of which is the laser scanner. In this paper, we propose a method to segment the measurement of the surrounding environment as obtained by a multi-layer laser scanner. In the segmentation, a full set of measurements is decomposed into several segments, each representing a single object. Sometimes a ghost is detected due to the ground or fog, and the ghost has to be eliminated to ensure the stability of the system. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments show that the proposed method demonstrates good performance in many real-life situations. PMID:25356645

  2. Remote sensing of foliar biochemistry with a terrestrial laser scanner

    NASA Astrophysics Data System (ADS)

    Eitel, J.; Vierling, L. A.; Long, D. S.

    2011-12-01

    Foliar biochemistry provides important information about the physiological status of plants. Several different tools and techniques have been developed to infer plant biochemistry (such as state and change of foliar nitrogen (N) and chlorophyll) using remote sensing. However, few techniques allow accurate mapping of foliar biochemistry in 3-dimensions at a sub-cm level. Scanning laser technology is available that measures the x,y,z location of each reflected laser pulse in addition to the intensity of the reflected laser light within a mm-scale ground instantaneous field of view at a very high sampling rate (up to 50,000 points sec-1 in this study). We examined the ability to quantify foliar N of spring wheat (Triticum aestivum L.) and chlorophyll content of two broadleaf tree species saplings (Quercus macrocarpa and Acer saccharum) using a green (532 nm) terrestrial laser scanner. The return intensity of the reflected green laser light was significantly correlated with foliar N concentration of wheat (r2 = 0.68) and the foliar chlorophyll content (r2 = 0.77) of the broadleaf saplings. The results indicate that laser scanners are useful to obtain spatially explicit estimates of foliar biochemistry.

  3. Using Laser Scanners to Augment the Systematic Error Pointing Model

    NASA Astrophysics Data System (ADS)

    Wernicke, D. R.

    2016-08-01

    The antennas of the Deep Space Network (DSN) rely on precise pointing algorithms to communicate with spacecraft that are billions of miles away. Although the existing systematic error pointing model is effective at reducing blind pointing errors due to static misalignments, several of its terms have a strong dependence on seasonal and even daily thermal variation and are thus not easily modeled. Changes in the thermal state of the structure create a separation from the model and introduce a varying pointing offset. Compensating for this varying offset is possible by augmenting the pointing model with laser scanners. In this approach, laser scanners mounted to the alidade measure structural displacements while a series of transformations generate correction angles. Two sets of experiments were conducted in August 2015 using commercially available laser scanners. When compared with historical monopulse corrections under similar conditions, the computed corrections are within 3 mdeg of the mean. However, although the results show promise, several key challenges relating to the sensitivity of the optical equipment to sunlight render an implementation of this approach impractical. Other measurement devices such as inclinometers may be implementable at a significantly lower cost.

  4. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems

    PubMed Central

    Jung, Jaehoon; Kim, Jeonghyun; Yoon, Sanghyun; Kim, Sangmin; Cho, Hyoungsig; Kim, Changjae; Heo, Joon

    2015-01-01

    The Simultaneous Localization and Mapping (SLAM) technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs): one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system’s trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach. PMID:25946627

  5. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems.

    PubMed

    Jung, Jaehoon; Kim, Jeonghyun; Yoon, Sanghyun; Kim, Sangmin; Cho, Hyoungsig; Kim, Changjae; Heo, Joon

    2015-01-01

    The Simultaneous Localization and Mapping (SLAM) technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs): one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system's trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach. PMID:25946627

  6. Localization Corrections for Mobile Laser Scanner Using Local Support-Based Outlier Filtering

    NASA Astrophysics Data System (ADS)

    Lehtola, V. V.; Virtanen, J.-P.; Rönnholm, P.; Nüchter, A.

    2016-06-01

    Following the pioneering work introduced in [Lehtola et al., ISPRS J. Photogramm. Remote Sens. 99, 2015, pp. 25-29], we extend the state-of-the-art intrinsic localization solution for a single two-dimensional (2D) laser scanner from one into (quasi) three dimensions (3D). By intrinsic localization, we mean that no external sensors are used to localize the scanner, such as inertial measurement devices (IMU) or global navigation satellite systems (GNSS). Specifically, the proposed method builds on a novel concept of local support-based filtering of outliers, which enables the use of six degrees-of-freedom (DoF) simultaneous localization and mapping (SLAM) for the purpose of enacting appropriate trajectory corrections into the previous one-dimensional solution. Moreover, the local support-based filtering concept is platform independent, and is therefore likely to be widely generalizable. The here presented overall method is yet limited into quasi-3D by its inability to recover trajectories with steep curvature, but in the future, it may be further extended into full 3D.

  7. Scanner position sensor for an integrated laser/film rangefiner

    SciTech Connect

    Berdanier, B. N.

    1985-09-24

    In an integrated laser/FLIR rangefinder a scanner position sensor comprising an LED of the array of LEDs of a forward looking infrared (FLIR) system, a reticle grating located at the image plane of LED optical path and a silicon detector positioned to receive the light passing through the reticle grating for producing a plurality of signals in response to light passing through each grating slot. One of the signals is selected for the synchronization logic for controlling the charging and firing of the laser. If there is no range return a second signal is selected for adjusting the position of the timing pulse.

  8. On analysis and visualization of full-waveform airborne laser scanner data

    NASA Astrophysics Data System (ADS)

    Soederman, Ulf; Persson, Asa; Toepel, Johanna; Ahlberg, Simon

    2005-05-01

    The ongoing technical developments on airborne laser scanner systems, with shorter pulses, increased operation altitudes, focal plane array detectors, full-waveform digitization and recoding, etc. provide new opportunities for the expansion and growth of military as well as civilian applications. However, for the continuing development of systems and applications one crucial issue is the research and development of new and efficient laser data processing methods for analysis and visualization. In this paper we will present some recent developments on visualization and analysis of full-waveform data. We will discuss visualization of waveform data by inserting the waveform samples in a 3D volume consisting of small 3D cells referred to as voxels. We will also present an approach for extracting additional 3D point data from the waveforms. The long term goal of this research is to develop methods for automated extraction of natural as well as man-made objects. The aim is to support the construction of high-fidelity 3D virtual environment models and detection and identification of man-made objects.

  9. Optical laser scanning of a leucodye micelle gel: preliminary results of a 3D dose verification of an IMRT treatment for a brain tumor

    NASA Astrophysics Data System (ADS)

    Vandecasteele, J.; De Deene, Y.

    2013-06-01

    In the present study an in-house developed leucodye micelle gel was used in combination with an in-house developed optical laser scanner for the 3D dose verification of an IMRT treatment of a pituitary adenoma. In an initial prospective study, a gel measured depth dose distribution of a square 6 MV photon beam was compared with an ion chamber measurement. In a second experiment, the gel and scanner were used to verify a clinical dose distribution on a recently installed linear accelerator. The calibration procedure is identified as the major source of dose deviations.

  10. SOI based electromagnetic MEMS scanners and applications in laser systems

    NASA Astrophysics Data System (ADS)

    Brown, G.; Bauer, R.; Lubeigt, W.; Uttamchandani, D.

    2013-03-01

    MEMS scanners are of interest for their potential as low-cost, low operating power devices for use in various photonic systems. The devices reported here are actuated by the electromagnetic force between a static external magnetic field and a current flowing through an SOI MEMS scanner. These scanners have several modes of operation: their mirrors may be rotated and maintained at a static angle (up to +/- 1.4 degrees), scanned rapidly (up to 500 Hz); or may be operated in a resonance mode, at the device's mechanical resonance frequency (~1.2 kHz) for higher rate scanning. The use of these scanners as a Q-switching element within a Nd:YAG laser cavity has been demonstrated. Pulse durations of 400 ns were obtained with a pulse energy of 58 μJ and a pulse peak power of 145 W. The use of an external magnetic field, generated by compact rare-earth magnets, allows a simple and cost-effective commercial fabrication process to be employed (the multi-user SOI process provided by MEMSCAP Inc) and avoids the requirement to deposit magnetic materials on the MEMS structure.

  11. One-mirror and two-mirror three-dimensional optical scanners--position and accuracy of laser beam spot.

    PubMed

    Pokorny, Petr

    2014-04-20

    This article presents several fundamental formulas for ray tracing in optical systems used in 3D optical scanners. A procedure for numerical modeling of one-mirror and two-mirror optical systems is presented, and the calculation of positioning and accuracy of the laser beam spot in a detection plane is carried out. Finally, a point position and accuracy depending on a transit time is evaluated. PMID:24787602

  12. Real-time motion- and B0-correction for LASER-localized spiral-accelerated 3D-MRSI of the brain at 3T

    PubMed Central

    Bogner, Wolfgang; Hess, Aaron T; Gagoski, Borjan; Tisdall, M. Dylan; van der Kouwe, Andre J.W.; Trattnig, Siegfried; Rosen, Bruce; Andronesi, Ovidiu C

    2013-01-01

    The full potential of magnetic resonance spectroscopic imaging (MRSI) is often limited by localization artifacts, motion-related artifacts, scanner instabilities, and long measurement times. Localized adiabatic selective refocusing (LASER) provides accurate B1-insensitive spatial excitation even at high magnetic fields. Spiral encoding accelerates MRSI acquisition, and thus, enables 3D-coverage without compromising spatial resolution. Real-time position-and shim/frequency-tracking using MR navigators correct motion- and scanner instability-related artifacts. Each of these three advanced MRI techniques provides superior MRSI data compared to commonly used methods. In this work, we integrated in a single pulse sequence these three promising approaches. Real-time correction of motion, shim, and frequency-drifts using volumetric dual-contrast echo planar imaging-based navigators were implemented in an MRSI sequence that uses low-power gradient modulated short-echo time LASER localization and time efficient spiral readouts, in order to provide fast and robust 3D-MRSI in the human brain at 3T. The proposed sequence was demonstrated to be insensitive to motion- and scanner drift-related degradations of MRSI data in both phantoms and volunteers. Motion and scanner drift artifacts were eliminated and excellent spectral quality was recovered in the presence of strong movement. Our results confirm the expected benefits of combining a spiral 3D-LASER-MRSI sequence with real-time correction. The new sequence provides accurate, fast, and robust 3D metabolic imaging of the human brain at 3T. This will further facilitate the use of 3D-MRSI for neuroscience and clinical applications. PMID:24201013

  13. Laser hazard analysis for various candidate diode lasers associated with the high resolution pulsed scanner.

    SciTech Connect

    Augustoni, Arnold L.

    2004-10-01

    A laser hazard analysis and safety assessment was performed for each various laser diode candidates associated with the High Resolution Pulse Scanner based on the ANSI Standard Z136.1-2000, American National Standard for the Safe Use of Lasers. A theoretical laser hazard analysis model for this system was derived and an Excel{reg_sign} spreadsheet model was developed to answer the 'what if questions' associated with the various modes of operations for the various candidate diode lasers.

  14. Experimental quantification of a granular crater induced by a liquid-to-granular impact using a 3D scanner

    NASA Astrophysics Data System (ADS)

    Wyser, Emmanuel; Abellan, Antonio; Carrea, Dario; Rudaz, Benjamin; Jaboyedoff, Michel

    2015-04-01

    Granular impacts have been extensively studied but much remains to be investigated regarding the complex topic of liquid-to-granular impact. Its applications to Geosciences are of interest regarding recent advances in the investigation of the raindrop erosion or the sediment flux. In our study, we focus on the quantification of both the excavated and deposited volumes resulting from a water-droplet impact onto a fine granular. The quantification of the existing relationships between the impact energy, the packing fraction and the excavated volume is also of interest. Indeed, the relationship between the packing fraction and the excavated volume has still to be investigated for constant impact energy (fixed height of fall and droplet size). Moreover, the volume distribution of the granular matter around the impact target has still to be achieved regarding the previous studies. Much of the previous work was focused on the ejected particles distribution but less is known about the volume distribution of the ejected mass. In this study, we have developed a specific methodology in order to investigate these two topics, as follows: a) First of all, we carried out experimental investigations in laboratory on a setup inspired by the previous works of Long et al. (2014) and Furbish et al. (2007). Granular samples were prepared using a compaction device in order to produce various packing fractions. Pre- and post-impact surface geometries were recorded using a high precision 3D scanner (KONICA MINOLTA VIVID 9i). This provided an accurate point cloud of the impact crater and ejecta deposits. b) Afterwards, we processed each point cloud pairs using different softwares (PolyWorks & MATLAB). We used an accurate change detection method by computing orthogonal distance from points (post-geometry) to reference meshed surface (pre-geometry) to extract the points belonging to deposits (positive distance) or crater (negative distance). Then, we used the computational geometry toolbox

  15. Electro-optic and acousto-optic laser beam scanners

    NASA Astrophysics Data System (ADS)

    Heberle, Johannes; Bechtold, Peter; Strauß, Johannes; Schmidt, Michael

    2016-03-01

    Electro-optical deflectors (EOD) and acousto-optical deflectors (AOD) are based on deflection of laser light within a solid state medium. As they do not contain any moving parts, they yield advantages compared to mechanical scanners which are conventionally used for laser beam deflection. Even for arbitrary scan paths high feed rates can be achieved. In this work the principles of operation and characteristic properties of EOD and AOD are presented. Additionally, a comparison to mirror based mechanical deflectors regarding deflection angles, speed and accuracy is made in terms of resolvable spots and the rate of resolvable spots. Especially, the latter one is up to one order of magnitude higher for EOD and AOD systems compared to conventional systems. Further characteristic properties such as response time, damage threshold, efficiency and beam distortions are discussed. Solid state laser beam deflectors are usually characterized by small deflection angles but high angular deflection velocities. As mechanical deflectors exhibit opposite properties an arrangement of a mechanical scanner combined with a solid state deflector provides a solution with the benefits of both systems. As ultrashort pulsed lasers with average power above 100 W and repetition rates in the MHz range have been available for several years this approach can be applied to fully exploit their capabilities. Thereby, pulse overlap can be reduced and by this means heat affected zones are prevented to provide proper processing results.

  16. Analysis of image quality for laser display scanner test

    NASA Astrophysics Data System (ADS)

    Specht, H.; Kurth, S.; Billep, D.; Gessner, T.

    2009-02-01

    The scanning laser display technology is one of the most promising technologies for highly integrated projection display applications (e. g. in PDAs, mobile phones or head mounted displays) due to its advantages regarding image quality, miniaturization level and low cost potential. As a couple of research teams found during their investigations on laser scanning projections systems, the image quality of such systems is - beside from laser source and video signal processing - crucially determined by the scan engine, including MEMS scanner, driving electronics, scanning regime and synchronization. Even though a number of technical parameters can be measured with high accuracy, the test procedure is challenging because the influence of these parameters on image quality is often insufficiently understood. Thus, in many cases it is not clear how to define limiting values for characteristic parameters. In this paper the relationship between parameters characterizing the scan engine and their influence on image quality will be discussed. Those include scanner topography, geometry of the path of light as well as trajectory parameters. Understanding this enables a new methodology for testing and characterization of the scan engine, based on evaluation of one or a series of projected test images. Due to the fact that the evaluation process can be easily automated by digital image processing this methodology has the potential to become integrated into the production process of laser displays.

  17. Speckle noise in laser bar-code-scanner systems

    NASA Astrophysics Data System (ADS)

    Yu, Daoqi; Stern, Miklos; Katz, Joseph

    1996-07-01

    We present a theoretical model and its experimental verification for speckle-induced noise in laser-based bar-code-scanner systems. We measured the dependence of the signal-to-speckle-noise ratio on distance, spot size, and detector size. Analyses of the power spectra of both the speckle noise and of the measured surface profiles of different substrates suggest that the paper surface granularity can be approximated by a white Gaussian noise process, thus confirming the assumption of the theoretical model.

  18. Laser direct writing 3D structures for microfluidic channels: flow meter and mixer

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Lang; Liu, Yi-Jui; Lin, Zheng-Da; Wu, Bo-Long; Lee, Yi-Hsiung; Shin, Chow-Shing; Baldeck, Patrice L.

    2015-03-01

    The 3D laser direct-writing technology is aimed at the modeling of arbitrary three-dimensional (3D) complex microstructures by scanning a laser-focusing point along predetermined trajectories. Through the perspective technique, the details of designed 3D structures can be properly fabricated in a microchannel. This study introduces a direct reading flow meter and a 3D passive mixer fabricated by laser direct writing for microfluidic applications. The flow meter consists of two rod-shaped springs, a pillar, an anchor, and a wedge-shaped indicator, installed inside a microfluidic channel. The indicator is deflected by the flowing fluid while restrained by the spring to establish an equilibrium indication according to the flow rate. The measurement is readily carried out by optical microscopy observation. The 3D passive Archimedes-screw-shaped mixer is designed to disturb the laminar flow 3D direction for enhancing the mixing efficiency. The simulation results indicate that the screw provides 3D disturbance of streamlines in the microchannel. The mixing demonstration for fluids flowing in the micrchannel approximately agrees with the simulation result. Thanks to the advantage of the laser direct writing technology, this study performs the ingenious applications of 3D structures for microchannels.

  19. Fabrication of Conductive 3D Gold-Containing Microstructures via Direct Laser Writing.

    PubMed

    Blasco, Eva; Müller, Jonathan; Müller, Patrick; Trouillet, Vanessa; Schön, Markus; Scherer, Torsten; Barner-Kowollik, Christopher; Wegener, Martin

    2016-05-01

    3D conductive microstructures containing gold are fabricated by simultaneous photopolymerization and photoreduction via direct laser writing. The photoresist employed consists of water-soluble polymers and a gold precursor. The fabricated microstructures show good conductivity and are successfully employed for 3D connections between gold pads. PMID:26953811

  20. Three-dimensional tracking and imaging laser scanner for space operations

    NASA Astrophysics Data System (ADS)

    Laurin, Denis G.; Beraldin, J. A.; Blais, Francois; Rioux, Marc; Cournoyer, Luc

    1999-05-01

    This paper presents the development of a laser range scanner (LARS) as a three-dimensional sensor for space applications. The scanner is a versatile system capable of doing surface imaging, target ranging and tracking. It is capable of short range (0.5 m to 20 m) and long range (20 m to 10 km) sensing using triangulation and time-of-flight (TOF) methods respectively. At short range (1 m), the resolution is sub-millimeter and drops gradually with distance (2 cm at 10 m). For long range, the TOF provides a constant resolution of plus or minus 3 cm, independent of range. The LARS could complement the existing Canadian Space Vision System (CSVS) for robotic manipulation. As an active vision system, the LARS is immune to sunlight and adverse lighting; this is a major advantage over the CSVS, as outlined in this paper. The LARS could also replace existing radar systems used for rendezvous and docking. There are clear advantages of an optical system over a microwave radar in terms of size, mass, power and precision. Equipped with two high-speed galvanometers, the laser can be steered to address any point in a 30 degree X 30 degree field of view. The scanning can be continuous (raster scan, Lissajous) or direct (random). This gives the scanner the ability to register high-resolution 3D images of range and intensity (up to 4000 X 4000 pixels) and to perform point target tracking as well as object recognition and geometrical tracking. The imaging capability of the scanner using an eye-safe laser is demonstrated. An efficient fiber laser delivers 60 mW of CW or 3 (mu) J pulses at 20 kHz for TOF operation. Implementation of search and track of multiple targets is also demonstrated. For a single target, refresh rates up to 137 Hz is possible. Considerations for space qualification of the scanner are discussed. Typical space operations, such as docking, object attitude tracking, and inspections are described.

  1. Investigation Into the Utilization of 3D Printing in Laser Cooling Experiments

    NASA Astrophysics Data System (ADS)

    Hazlett, Eric; Nelson, Brandon; de Leon, Sam Diaz; Shaw, Jonah

    2016-05-01

    With the advancement of 3D printing new opportunities are abound in many different fields, but with the balance between the precisions of atomic physics experiments and the material properties of current 3D printers the benefit of 3D printing technology needs to be investigated. We report on the progress of two investigations of 3D printing of benefit to atomic physics experiments: laser feedback module and the other being an optical chopper. The first investigation looks into creation of a 3D printed laser diode feedback module. This 3D printed module would allow for the quick realization of an external cavity diode laser that would have an adjustable cavity distance. We will report on the first tests of this system, by looking at Rb spectroscopy and mode-hop free tuning range as well as possibilities of using these lasers for MOT generation. We will also discuss our investigation into a 3D-printed optical chopper that utilizes an Arduino and a computer hard drive motor. By implementing an additional Arduino we create a low cost way to quickly measure laser beam waists.

  2. Investigation Into the Utilization of 3D Printing in Laser Cooling Experiments

    NASA Astrophysics Data System (ADS)

    Hazlett, Eric

    With the advancement of 3D printing new opportunities are abound in many different fields, but with the balance between the precisions of atomic physics experiments and the material properties of current 3D printers the benefit of 3D printing technology needs to be investigated. We report on the progress of two investigations of 3D printing of benefit to atomic physics experiments: laser feedback module and the other being an optical chopper. The first investigation looks into creation of a 3D printed laser diode feedback module. This 3D printed module would allow for the quick realization of an external cavity diode laser that would have an adjustable cavity distance. We will report on the first tests of this system, by looking at Rb spectroscopy and mode-hop free tuning range as well as possibilities of using these lasers for MOT generation. We will also discuss our investigation into a 3D-printed optical chopper that utilizes an Arduino and a computer hard drive motor. By implementing an additional Arduino we create a low cost way to quickly measure laser beam waists

  3. Application of a laser scanner to three dimensional visual sensing tasks

    NASA Technical Reports Server (NTRS)

    Ryan, Arthur M.

    1992-01-01

    The issues are described which are associated with using a laser scanner for visual sensing and the methods developed by the author to address them. A laser scanner is a device that controls the direction of a laser beam by deflecting it through a pair of orthogonal mirrors, the orientations of which are specified by a computer. If a calibrated laser scanner is combined with a calibrated camera, it is possible to perform three dimensional sensing by directing the laser at objects within the field of view of the camera. There are several issues associated with using a laser scanner for three dimensional visual sensing that must be addressed in order to use the laser scanner effectively. First, methods are needed to calibrate the laser scanner and estimate three dimensional points. Second, methods to estimate three dimensional points using a calibrated camera and laser scanner are required. Third, methods are required for locating the laser spot in a cluttered image. Fourth, mathematical models that predict the laser scanner's performance and provide structure for three dimensional data points are necessary. Several methods were developed to address each of these and has evaluated them to determine how and when they should be applied. The theoretical development, implementation, and results when used in a dual arm eighteen degree of freedom robotic system for space assembly is described.

  4. Application to monitoring of tailings dam based on 3D laser scanning technology

    NASA Astrophysics Data System (ADS)

    Ren, Fang; Zhang, Aiwu

    2011-06-01

    This paper presented a new method of monitoring of tailing dam based on 3D laser scanning technology and gave the method flow of acquiring and processing the tailing dam data. Taking the measured data for example, the author analyzed the dam deformation by generating the TIN, DEM and the curvature graph, and proved that it's feasible to global monitor the tailing dam using 3D laser scanning technology from the theory and method.

  5. Laser Provides First 3-D View of Mars' North Pole

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This first three-dimensional picture of Mars' north pole enables scientists to estimate the volume of its water ice cap with unprecedented precision, and to study its surface variations and the heights of clouds in the region for the first time.

    Approximately 2.6 million of these laser pulse measurements were assembled into a topographic grid of the north pole with a spatial resolution of 0.6 miles (one kilometer) and a vertical accuracy of 15-90 feet (5-30 meters).

    The principal investigator for MOLA is Dr. David E. Smith of Goddard. The MOLA instrument was designed and built by the Laser Remote Sensing Branch of Laboratory for Terrestrial Physics at Goddard. The Mars Global Surveyor Mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for the NASA Office of Space Science.

  6. Laser-assisted direct ink writing of planar and 3D metal architectures

    PubMed Central

    Skylar-Scott, Mark A.; Gunasekaran, Suman; Lewis, Jennifer A.

    2016-01-01

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features “on-the-fly.” To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates. PMID:27185932

  7. Laser-assisted direct ink writing of planar and 3D metal architectures.

    PubMed

    Skylar-Scott, Mark A; Gunasekaran, Suman; Lewis, Jennifer A

    2016-05-31

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features "on-the-fly." To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates. PMID:27185932

  8. Laser-assisted direct ink writing of planar and 3D metal architectures

    NASA Astrophysics Data System (ADS)

    Skylar-Scott, Mark A.; Gunasekaran, Suman; Lewis, Jennifer A.

    2016-05-01

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features “on-the-fly.” To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates.

  9. Formation and properties of 3D metamaterial composites fabricated using nanometer scale laser lithography (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Prokes, Sharka M.; Perkins, Frank K.; Glembocki, Orest J.

    2015-08-01

    Metamaterials designed for the visible or near IR wavelengths require patterning on the nanometer scale. To achieve this, e-beam lithography is used, but it is extremely difficult and can only produce 2D structures. A new alternative technique to produce 2D and 3D structures involves laser fabrication using the Nanoscribe 3D laser lithography system. This is a direct laser writing technique which can form arbitrary 3D nanostructures on the nanometer scale and is based on multi-photon polymerization. We are creating 2D and 3D metamaterials via this technique, and subsequently conformally coating them using Atomic Layer Deposition of oxides and Ag. We will discuss the optical properties of these novel composite structures and their potential for dual resonant metamaterials.

  10. Progress in Tridimensional (3d) Laser Forming of Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Gisario, Annamaria; Barletta, Massimiliano; Venettacci, Simone; Veniali, Francesco

    2015-09-01

    Achievement of complex shapes with high dimensional accuracy and precision by forming process is a demanding challenge for scientists and practitioners. Available technologies are numerous, with laser forming being progressively emerging because of limited springback, lack of molds and sophisticated auxiliary equipments. However, laser forming finds limited applications, especially when forming of tridimensional (3d) complex shapes is required. In this case, cost savings are often counterbalanced by the need for troublesome forming strategies. Therefore, traditional alternatives based on mechanical devices are usually preferred to laser systems. In the present work, 3d laser forming of stainless steel sheets by high power diode laser is investigated. In particular, the set of scanning patterns to form domes from flat blanks by simple and easy-to-manage radial paths alone was found. Numerous 3d items were also processed by diode laser to manufacture a number of complex shapes with high flexibility and limited efforts to modify the auxiliary forming equipment. Based on the experimental results and analytical data, the high power diode laser was found able to form arbitrary 3d shapes through the implementation of tailored laser scanning patterns and appropriate settings of the operational parameters.

  11. Filtering method for 3D laser scanning point cloud

    NASA Astrophysics Data System (ADS)

    Liu, Da; Wang, Li; Hao, Yuncai; Zhang, Jun

    2015-10-01

    In recent years, with the rapid development of the hardware and software of the three-dimensional model acquisition, three-dimensional laser scanning technology is utilized in various aspects, especially in space exploration. The point cloud filter is very important before using the data. In the paper, considering both the processing quality and computing speed, an improved mean-shift point cloud filter method is proposed. Firstly, by analyze the relevance of the normal vector between the upcoming processing point and the near points, the iterative neighborhood of the mean-shift is selected dynamically, then the high frequency noise is constrained. Secondly, considering the normal vector of the processing point, the normal vector is updated. Finally, updated position is calculated for each point, then each point is moved in the normal vector according to the updated position. The experimental results show that the large features are retained, at the same time, the small sharp features are also existed for different size and shape of objects, so the target feature information is protected precisely. The computational complexity of the proposed method is not high, it can bring high precision results with fast speed, so it is very suitable for space application. It can also be utilized in civil, such as large object measurement, industrial measurement, car navigation etc. In the future, filter with the help of point strength will be further exploited.

  12. 3-D CFD in a day - The laser digitizer project

    NASA Technical Reports Server (NTRS)

    Merriam, Marshal; Barth, Tim

    1991-01-01

    The computation of airflow over complex configurations requires a complete description of the geometry. This can be obtained from CAD data, from blueprints, or from actual models. In any case, the time required is currently estimated at 4 to 6 months. It is proposed to shorten this time by a factor of 10 to 100 through the use of automated software, a fast, highly parallel computer and a three-dimensional laser digitizer. This device can provide (x,y,z) coordinates of surface points at rates exceeding 14,500/sec. Thus, it is possible to digitize an entire model in a few minutes. The accuracy of measurement on a flat white surface is better than 0.005 inches. Higher accuracy is available at higher cost. This work discusses the challenges which remain to be addressed. In particular, the surface point data need to be converted into a surface description, the surface description needs to be made into a surface grid, and the surface grid used to make a volume grid for the flow solver. Algorithms are kept in place or in mind for all of these problems. Integration of the more mature flow solution and visualization algorithms then allows generation of solution graphics directly from a wind tunnel model.

  13. Beat the diffraction limit in 3D direct laser writing in photosensitive glass.

    PubMed

    Bellec, Matthieu; Royon, Arnaud; Bousquet, Bruno; Bourhis, Kevin; Treguer, Mona; Cardinal, Thierry; Richardson, Martin; Canioni, Lionel

    2009-06-01

    Three-dimensional (3D) femtosecond laser direct structuring in transparent materials is widely used for photonic applications. However, the structure size is limited by the optical diffraction. Here we report on a direct laser writing technique that produces subwavelength nanostructures independently of the experimental limiting factors. We demonstrate 3D nanostructures of arbitrary patterns with feature sizes down to 80 nm, less than one tenth of the laser processing wavelength. Its ease of implementation for novel nanostructuring, with its accompanying high precision will open new opportunities for the fabrication of nanostructures for plasmonic and photonic devices and for applications in metamaterials. PMID:19506684

  14. Design of smart 3D-digital X-ray microtomographic scanners for non-destructive testing of materials and components of electronic devices with a multilayered structure

    SciTech Connect

    Syryamkin, V. I. Klestov, S. A. Echina, E. S.; Suntsov, S. B.

    2015-10-27

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. Chapter 4 covers general procedures of defect search, which is based on vector analysis principles. In conclusion, the main applications of X-ray tomography are presented.

  15. Design of smart 3D-digital X-ray microtomographic scanners for non-destructive testing of materials and components of electronic devices with a multilayered structure

    NASA Astrophysics Data System (ADS)

    Syryamkin, V. I.; Suntsov, S. B.; Klestov, S. A.; Echina, E. S.

    2015-10-01

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. Chapter 4 covers general procedures of defect search, which is based on vector analysis principles. In conclusion, the main applications of X-ray tomography are presented.

  16. LATIS3D: The Goal Standard for Laser-Tissue-Interaction Modeling

    NASA Astrophysics Data System (ADS)

    London, R. A.; Makarewicz, A. M.; Kim, B. M.; Gentile, N. A.; Yang, T. Y. B.

    2000-03-01

    The goal of this LDRD project has been to create LATIS3D-the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications. The purpose of this project was to develop and apply a computer program for laser-tissue interaction modeling to aid in the development of new instruments and procedures in laser medicine.

  17. Fabrication of 3D microfluidic structures inside glass by femtosecond laser micromachining

    NASA Astrophysics Data System (ADS)

    Sugioka, Koji; Cheng, Ya

    2014-01-01

    Femtosecond lasers have opened up new avenues in materials processing due to their unique characteristics of ultrashort pulse widths and extremely high peak intensities. One of the most important features of femtosecond laser processing is that a femtosecond laser beam can induce strong absorption in even transparent materials due to nonlinear multiphoton absorption. This makes it possible to directly create three-dimensional (3D) microfluidic structures in glass that are of great use for fabrication of biochips. For fabrication of the 3D microfluidic structures, two technical approaches are being attempted. One of them employs femtosecond laser-induced internal modification of glass followed by wet chemical etching using an acid solution (Femtosecond laser-assisted wet chemical etching), while the other one performs femtosecond laser 3D ablation of the glass in distilled water (liquid-assisted femtosecond laser drilling). This paper provides a review on these two techniques for fabrication of 3D micro and nanofluidic structures in glass based on our development and experimental results.

  18. Laser nanostructuring 3-D bioconstruction based on carbon nanotubes in a water matrix of albumin

    NASA Astrophysics Data System (ADS)

    Gerasimenko, Alexander Y.; Ichkitidze, Levan P.; Podgaetsky, Vitaly M.; Savelyev, Mikhail S.; Selishchev, Sergey V.

    2016-04-01

    3-D bioconstructions were created using the evaporation method of the water-albumin solution with carbon nanotubes (CNTs) by the continuous and pulsed femtosecond laser radiation. It is determined that the volume structure of the samples created by the femtosecond radiation has more cavities than the one created by the continuous radiation. The average diameter for multi-walled carbon nanotubes (MWCNTs) samples was almost two times higher (35-40 nm) than for single-walled carbon nanotubes (SWCNTs) samples (20-30 nm). The most homogenous 3-D bioconstruction was formed from MWCNTs by the continuous laser radiation. The hardness of such samples totaled up to 370 MPa at the nanoscale. High strength properties and the resistance of the 3-D bioconstructions produced by the laser irradiation depend on the volume nanotubes scaffold forming inside them. The scaffold was formed by the electric field of the directed laser irradiation. The covalent bond energy between the nanotube carbon molecule and the oxygen of the bovine serum albumin aminoacid residue amounts 580 kJ/mol. The 3-D bioconstructions based on MWCNTs and SWCNTs becomes overgrown with the cells (fibroblasts) over the course of 72 hours. The samples based on the both types of CNTs are not toxic for the cells and don't change its normal composition and structure. Thus the 3-D bioconstructions that are nanostructured by the pulsed and continuous laser radiation can be applied as implant materials for the recovery of the connecting tissues of the living body.

  19. The fast and accurate 3D-face scanning technology based on laser triangle sensors

    NASA Astrophysics Data System (ADS)

    Wang, Jinjiang; Chang, Tianyu; Ge, Baozhen; Tian, Qingguo; Chen, Yang; Kong, Bin

    2013-08-01

    A laser triangle scanning method and the structure of 3D-face measurement system were introduced. In presented system, a liner laser source was selected as an optical indicated signal in order to scanning a line one times. The CCD image sensor was used to capture image of the laser line modulated by human face. The system parameters were obtained by system calibrated calculated. The lens parameters of image part of were calibrated with machine visual image method and the triangle structure parameters were calibrated with fine wire paralleled arranged. The CCD image part and line laser indicator were set with a linear motor carry which can achieve the line laser scanning form top of the head to neck. For the nose is ledge part and the eyes are sunk part, one CCD image sensor can not obtain the completed image of laser line. In this system, two CCD image sensors were set symmetric at two sides of the laser indicator. In fact, this structure includes two laser triangle measure units. Another novel design is there laser indicators were arranged in order to reduce the scanning time for it is difficult for human to keep static for longer time. The 3D data were calculated after scanning. And further data processing include 3D coordinate refine, mesh calculate and surface show. Experiments show that this system has simply structure, high scanning speed and accurate. The scanning range covers the whole head of adult, the typical resolution is 0.5mm.

  20. Laser fabrication of 2D and 3D metal nanoparticle structures and arrays.

    PubMed

    Kuznetsov, A I; Kiyan, R; Chichkov, B N

    2010-09-27

    A novel method for fabrication of 2D and 3D metal nanoparticle structures and arrays is proposed. This technique is based on laser-induced transfer of molten metal nanodroplets from thin metal films. Metal nanoparticles are produced by solidification of these nanodroplets. The size of the transferred nanoparticles can be controllably changed in the range from 180 nm to 1500 nm. Several examples of complex 2D and 3D microstructures generated form gold nanoparticles are demonstrated. PMID:20941016

  1. Laser Transfer of Metals and Metal Alloys for Digital Microfabrication of 3D Objects.

    PubMed

    Zenou, Michael; Sa'ar, Amir; Kotler, Zvi

    2015-09-01

    3D copper logos printed on epoxy glass laminates are demonstrated. The structures are printed using laser transfer of molten metal microdroplets. The example in the image shows letters of 50 µm width, with each letter being taller than the last, from a height of 40 µm ('s') to 190 µm ('l'). The scanning microscopy image is taken at a tilt, and the topographic image was taken using interferometric 3D microscopy, to show the effective control of this technique. PMID:25966320

  2. Multi-temporal Terrestrial Laser Scanner monitoring of coastal instability processes at Coroglio cliff

    NASA Astrophysics Data System (ADS)

    Caputo, Teresa; Somma, Renato; Marino, Ermanno; Matano, Fabio; Troise, Claudia; De Natale, Giuseppe

    2016-04-01

    The Coroglio cliff is a morphological evolution of the caldera rim of Neapolitan Yellow Tuff (NYT) in Campi Flegrei caldera (CFc) with an elevation of 150 m a.s.l. and a length of about 200 m. The lithology consists of NYT, extremely lithified, overlaid by less lithified recent products of the Phlegrean volcanism., These materials are highly erodible and, due to proximity to the sea, the sea wave and wind actions cause very strong erosion process. In the recent years Terrestrial Laser Scanner (TLS) technique is used for environmental monitoring purposes through the creation of high resolution Digital Surface Model (DSM) and Digital Terrain Model (DTM). This method allows the reconstruction, by means of a dense cloud of points, of a 3D model for the entire investigated area. The scans need to be performed from different points of view in order to ensure a good coverage of the area, because a widespread problem is the occurrence of shaded areas. In our study we used a long-range laser scanner model RIEGL VZ1000®. Numerous surveys (April 2013, June 2014, February 2015) have been performed for monitoring coastal cliff morphological evolution. An additional survey was executed in March 2015, shortly after a landslide occurrence. To validate the multi-temporal monitoring of the laser scanner, a "quick" comparison of the acquired point clouds has been carried out using an algorithm cloud-to-cloud, in order to identify 3D changes. Then 2.5D raster images of the different scans has been performed in GIS environment, also in order to allow a map overlay of the produced thematic layer, both raster and vector data (geology, contour map, orthophoto, and so on). The comparison of multi-temporal data have evidenced interesting geomorphological processes on the cliff. It was observed a very intense (about 6 m) local moving back at the base of the cliff, mainly due to the sea wave action during storms, while in cliff sectors characterized by less compact lithologies widespread

  3. Laser point cloud diluting and refined 3D reconstruction fusing with digital images

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Zhang, Jianqing

    2007-06-01

    This paper shows a method to combine the imaged-based modeling technique and Laser scanning data to rebuild a realistic 3D model. Firstly use the image pair to build a relative 3D model of the object, and then register the relative model to the Laser coordinate system. Project the Laser points to one of the images and extract the feature lines from that image. After that fit the 2D projected Laser points to lines in the image and constrain their corresponding 3D points to lines in the 3D Laser space to keep the features of the model. Build TIN and cancel the redundant points, which don't impact the curvature of their neighborhood areas. Use the diluting Laser point cloud to reconstruct the geometry model of the object, and then project the texture of corresponding image onto it. The process is shown to be feasible and progressive proved by experimental results. The final model is quite similar with the real object. This method cuts down the quantity of data in the precondition of keeping the features of model. The effect of it is manifest.

  4. Absorption spectrum of the laser-populated 3D metastable levels in barium

    NASA Technical Reports Server (NTRS)

    Carlsten, J. L.; Mcilrath, T. J.; Parkinson, W. H.

    1975-01-01

    This paper deals with the details of the absorption spectrum of the 3D metastable term in barium. The 3D term was selectively populated with a tuneable dye laser. The fundamental triplet series (6s5d 3D-6snf 3F) is identified and extended out to n = 32. In addition, the absolute photoionization cross section was measured at 303 nm. The relative cross section from 303 to 250 nm was also measured with the absolute scale set by the measurement at 303 nm and was found to be nearly constant in the wavelength region measured.

  5. Fabrication of 3D solenoid microcoils in silica glass by femtosecond laser wet etch and microsolidics

    NASA Astrophysics Data System (ADS)

    Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Du, Guangqing; Hou, Xun

    2015-02-01

    This paper reports a flexible fabrication method for 3D solenoid microcoils in silica glass. The method consists of femtosecond laser wet etching (FLWE) and microsolidics process. The 3D microchannel with high aspect ratio is fabricated by an improved FLWE method. In the microsolidics process, an alloy was chosen as the conductive metal. The microwires are achieved by injecting liquid alloy into the microchannel, and allowing the alloy to cool and solidify. The alloy microwires with high melting point can overcome the limitation of working temperature and improve the electrical property. The geometry, the height and diameter of microcoils were flexibly fabricated by the pre-designed laser writing path, the laser power and etching time. The 3D microcoils can provide uniform magnetic field and be widely integrated in many magnetic microsystems.

  6. Burr-like, laser-made 3D microscaffolds for tissue spheroid encagement.

    PubMed

    Danilevicius, Paulius; Rezende, Rodrigo A; Pereira, Frederico D A S; Selimis, Alexandros; Kasyanov, Vladimir; Noritomi, Pedro Y; da Silva, Jorge V L; Chatzinikolaidou, Maria; Farsari, Maria; Mironov, Vladimir

    2015-01-01

    The modeling, fabrication, cell loading, and mechanical and in vitro biological testing of biomimetic, interlockable, laser-made, concentric 3D scaffolds are presented. The scaffolds are made by multiphoton polymerization of an organic-inorganic zirconium silicate. Their mechanical properties are theoretically modeled using finite elements analysis and experimentally measured using a Microsquisher(®). They are subsequently loaded with preosteoblastic cells, which remain live after 24 and 72 h. The interlockable scaffolds have maintained their ability to fuse with tissue spheroids. This work represents a novel technological platform, enabling the rapid, laser-based, in situ 3D tissue biofabrication. PMID:26104190

  7. 3D printing of weft knitted textile based structures by selective laser sintering of nylon powder

    NASA Astrophysics Data System (ADS)

    Beecroft, M.

    2016-07-01

    3D printing is a form of additive manufacturing whereby the building up of layers of material creates objects. The selective laser sintering process (SLS) uses a laser beam to sinter powdered material to create objects. This paper builds upon previous research into 3D printed textile based material exploring the use of SLS using nylon powder to create flexible weft knitted structures. The results show the potential to print flexible textile based structures that exhibit the properties of traditional knitted textile structures along with the mechanical properties of the material used, whilst describing the challenges regarding fineness of printing resolution. The conclusion highlights the potential future development and application of such pieces.

  8. Three-Dimensional Recording of Bastion Middleburg Monument Using Terrestrial Laser Scanner

    NASA Astrophysics Data System (ADS)

    Majid, Z.; Lau, C. L.; Yusoff, A. R.

    2016-06-01

    This paper describes the use of terrestrial laser scanning for the full three-dimensional (3D) recording of historical monument, known as the Bastion Middleburg. The monument is located in Melaka, Malaysia, and was built by the Dutch in 1660. This monument serves as a major hub for the community when conducting commercial activities in estuaries Malacca and the Dutch build this monument as a control tower or fortress. The monument is located on the banks of the Malacca River was built between Stadhuys or better known as the Red House and Mill Quayside. The breakthrough fort on 25 November 2006 was a result of the National Heritage Department through in-depth research on the old map. The recording process begins with the placement of measuring targets at strategic locations around the monument. Spherical target was used in the point cloud data registration. The scanning process is carried out using a laser scanning system known as a terrestrial scanner Leica C10. This monument was scanned at seven scanning stations located surrounding the monument with medium scanning resolution mode. Images of the monument have also been captured using a digital camera that is setup in the scanner. For the purposes of proper registration process, the entire spherical target was scanned separately using a high scanning resolution mode. The point cloud data was pre-processed using Leica Cyclone software. The pre-processing process starting with the registration of seven scan data set through overlapping spherical targets. The post-process involved in the generation of coloured point cloud model of the monument using third-party software. The orthophoto of the monument was also produced. This research shows that the method of laser scanning provides an excellent solution for recording historical monuments with true scale of and texture.

  9. Laser-excited confocal-fluorescence gel scanner

    SciTech Connect

    Mathies, R.A.; Scherer, J.R.; Quesada, M.A. ); Rye, H.S.; Glazer, A.N. )

    1994-04-01

    A high-sensitivity, laser-excited, confocal-fluorescence scanner has been developed for the detection of fluorescently labeled nucleic acids separated on slab gels. The gel is placed on a motor-driven, two-dimensional scan stage and raster scanned past the optical detection system. The 488-nm argon ion laser beam is introduced into the confocal optical system at a long-pass dichroic beam splitter and focused within the gel to an [similar to]2 [mu]m diameter spot by a high-numerical aperture microscope objective. The resulting fluorescence is gathered by the objective, passed back through the first long-pass beam splitter, and relayed to a second dichroic beam splitter that separates the red and green emissions. The fluorescence is then focused on confocal spatial filters to reduce stray and scattered light, passed through spectral filters, and detected with photomultipliers. The resulting signals are amplified, filtered, and digitized for display on a computer. This system can detect as little as 5[times]10[sup [minus]12] M fluorescein, the resolution as operated is 160 [mu]m, and it can scan a 6 cm[times]6 cm gel using a scan rate of 4 cm/s in 12 min. The detection of DNA on slab gels, two-color DNA fragment sizing, and microtiter plate scanning are presented to illustrate some of the possible applications of this apparatus.

  10. a Light-Weight Laser Scanner for Uav Applications

    NASA Astrophysics Data System (ADS)

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    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.

  11. Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling

    SciTech Connect

    Rainey, E. S. G.; Kavner, A.; Hernlund, J. W.

    2013-11-28

    We present TempDAC, a 3-D numerical model for calculating the steady-state temperature distribution for continuous wave laser-heated experiments in the diamond anvil cell. TempDAC solves the steady heat conduction equation in three dimensions over the sample chamber, gasket, and diamond anvils and includes material-, temperature-, and direction-dependent thermal conductivity, while allowing for flexible sample geometries, laser beam intensity profile, and laser absorption properties. The model has been validated against an axisymmetric analytic solution for the temperature distribution within a laser-heated sample. Example calculations illustrate the importance of considering heat flow in three dimensions for the laser-heated diamond anvil cell. In particular, we show that a “flat top” input laser beam profile does not lead to a more uniform temperature distribution or flatter temperature gradients than a wide Gaussian laser beam.

  12. LATIS3D: The Gold Standard for Laser-Tissue-Interaction Modeling

    SciTech Connect

    London, R.A.; Makarewicz, A.M.; Kim, B.M.; Gentile, N.A.; Yang, Y.B.; Brlik, M.; Vincent, L.

    2000-02-29

    The goal of this LDRD project has been to create LATIS3D--the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications.

  13. Black silicon: substrate for laser 3D micro/nano-polymerization.

    PubMed

    Žukauskas, Albertas; Malinauskas, Mangirdas; Kadys, Arūnas; Gervinskas, Gediminas; Seniutinas, Gediminas; Kandasamy, Sasikaran; Juodkazis, Saulius

    2013-03-25

    We demonstrate that black silicon (b-Si) made by dry plasma etching is a promising substrate for laser three-dimensional (3D) micro/nano-polymerization. High aspect ratio Si-needles, working as sacrificial support structures, have flexibility required to relax interface stresses between substrate and the polymerized micro-/nano- objects. Surface of b-Si can be made electrically conductive by metal deposition and, at the same time, can preserve low optical reflectivity beneficial for polymerization by direct laser writing. 3D laser polymerization usually performed at the irradiation conditions close to the dielectric breakdown is possible on non-reflective and not metallic surfaces. Here we show that low reflectivity and high metallic conductivity are not counter- exclusive properties for laser polymerization. Electrical conductivity of substrate and its permeability in liquids are promising for bio- and electroplating applications. PMID:23546073

  14. Study of 3D Laser Cladding for Ni85Al15 Superalloy

    NASA Astrophysics Data System (ADS)

    Kotoban, D.; Grigoriev, S.; Shishkovsky, I.

    Conditions of successful3D laser cladding for Ni based superalloy were studied. A high power Yb-YAG laser was used to create a molten pool on a stainless steel substrate into which Ni85Al15 powder stream was delivered to create 3D samples. The effect of different laser parameters on the structure and the intermetallic phase content of the manufactured samples were explored by optical metallography, microhardness, SEM, X-ray, and EDX analysis. The cladding of the Ni3A1 coating with small dilution into substrate can be obtained at the appropriate power density of about 2-8 J/mm2 under the laser scan velocity of 100-200 mm/min and the powder feed rate ∼ 3.8 g/min.

  15. Body mass estimations for Plateosaurus engelhardti using laser scanning and 3D reconstruction methods

    NASA Astrophysics Data System (ADS)

    Gunga, Hanns-Christian; Suthau, Tim; Bellmann, Anke; Friedrich, Andreas; Schwanebeck, Thomas; Stoinski, Stefan; Trippel, Tobias; Kirsch, Karl; Hellwich, Olaf

    2007-08-01

    Both body mass and surface area are factors determining the essence of any living organism. This should also hold true for an extinct organism such as a dinosaur. The present report discusses the use of a new 3D laser scanner method to establish body masses and surface areas of an Asian elephant (Zoological Museum of Copenhagen, Denmark) and of Plateosaurus engelhardti, a prosauropod from the Upper Triassic, exhibited at the Paleontological Museum in Tübingen (Germany). This method was used to study the effect that slight changes in body shape had on body mass for P. engelhardti. It was established that body volumes varied between 0.79 m3 (slim version) and 1.14 m3 (robust version), resulting in a presumable body mass of 630 and 912 kg, respectively. The total body surface areas ranged between 8.8 and 10.2 m2, of which, in both reconstructions of P. engelhardti, ˜33% account for the thorax area alone. The main difference between the two models is in the tail and hind limb reconstruction. The tail of the slim version has a surface area of 1.98 m2, whereas that of the robust version has a surface area of 2.73 m2. The body volumes calculated for the slim version were as follows: head 0.006 m3, neck 0.016 m3, fore limbs 0.020 m3, hind limbs 0.08 m3, thoracic cavity 0.533 m3, and tail 0.136 m3. For the robust model, the following volumes were established: 0.01 m3 head, neck 0.026 m3, fore limbs 0.025 m3, hind limbs 0.18 m3, thoracic cavity 0.616 m3, and finally, tail 0.28 m3. Based on these body volumes, scaling equations were used to assess the size that the organs of this extinct dinosaur have.

  16. Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing.

    PubMed

    Chen, Hongliang; Guo, Kaijing; Yang, Huilin; Wu, Dongying; Yuan, Feng

    2016-01-01

    BACKGROUND The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. MATERIAL AND METHODS Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. RESULTS With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. CONCLUSIONS A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws. PMID:27194139

  17. Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing

    PubMed Central

    Chen, Hongliang; Guo, Kaijing; Yang, Huilin; Wu, Dongying; Yuan, Feng

    2016-01-01

    Background The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. Material/Methods Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. Results With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. Conclusions A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws. PMID:27194139

  18. Automated generation of NC part programs for excimer laser ablation micromachining from known 3D surfaces

    NASA Astrophysics Data System (ADS)

    Mutapcic, Emir; Iovenitti, Pio G.; Hayes, Jason P.

    2002-11-01

    The purpose of this research project is to improve the capability of the laser micromachinning process, so that any desired 3D surface can be produced by taking the 3D information from a CAD system and automatically generating the NC part programs. In addition, surface quality should be able to be controlled by specifying optimised parameters. This paper presents the algorithms and a software system, which processes 3D geometry in an STL file format from a CAD system and produces the NC part program to mill the surface using the Excimer laser ablation process. Simple structures are used to demonstrate the prototype system's part programming capabilities, and an actual surface is machined.

  19. 3D pulsed laser-triggered high-speed microfluidic fluorescence-activated cell sorter.

    PubMed

    Chen, Yue; Wu, Ting-Hsiang; Kung, Yu-Chun; Teitell, Michael A; Chiou, Pei-Yu

    2013-11-12

    We report a 3D microfluidic pulsed laser-triggered fluorescence-activated cell sorter capable of sorting at a throughput of 23 000 cells per s with 90% purity in high-purity mode and at a throughput of 45 000 cells per s with 45% purity in enrichment mode in one stage and in a single channel. This performance is realized by exciting laser-induced cavitation bubbles in a 3D PDMS microfluidic channel to generate high-speed liquid jets that deflect detected fluorescent cells and particles focused by 3D sheath flows. The ultrafast switching mechanism (20 μs complete on-off cycle), small liquid jet perturbation volume, and three-dimensional sheath flow focusing for accurate timing control of fast (1.5 m s(-1)) passing cells and particles are three critical factors enabling high-purity sorting at high-throughput in this sorter. PMID:23844418

  20. Laser nanolithography and chemical metalization for the manufacturing of 3D metallic interconnects

    NASA Astrophysics Data System (ADS)

    Jonavičius, Tomas; RekštytÄ--, Sima; Žukauskas, Albertas; Malinauskas, Mangirdas

    2014-03-01

    We present a developed method based on direct laser writing (DLW) and chemical metallization (CM) for microfabrication of three-dimensional (3D) metallic structures. Such approach enables manufacturing of free­-form electro conductive interconnects which can be used in integrated electric circuits such micro-opto-electro mechanical systems (MOEMS). The proposed technique employing ultrafast high repetition rate laser enables efficient fabrication of 3D microstructures on dielectric as well as conductive substrates. The produced polymer links out of organic-inorganic composite matrix after CM serve as interconnects of separate metallic contacts, their dimensions are: height 15μm, width 5μm, length 35-45 μm and could provide 300 nΩm resistivity measured in a macroscopic way. This proves the techniques potential for creating integrated 3D electric circuits at microscale.

  1. Generation of 3D ellipsoidal laser beams by means of a profiled volume chirped Bragg grating

    NASA Astrophysics Data System (ADS)

    Mironov, S. Yu; Poteomkin, A. K.; Gacheva, E. I.; Andrianov, A. V.; Zelenogorskii, V. V.; Vasiliev, R.; Smirnov, V.; Krasilnikov, M.; Stephan, F.; Khazanov, E. A.

    2016-05-01

    A method for shaping photocathode laser driver pulses into 3D ellipsoidal form has been proposed and implemented. The key idea of the method is to use a chirped Bragg grating recorded within the ellipsoid volume and absent outside it. If a beam with a constant (within the grating reflection band) spectral density and uniform (within the grating aperture) cross-section is incident on such a grating, the reflected beam will be a 3D ellipsoid in space and time. 3D ellipsoidal beams were obtained in experiment for the first time. It is expected that such laser beams will allow the electron bunch emittance to be reduced when applied at R± photo injectors.

  2. Model studies of blood flow in basilar artery with 3D laser Doppler anemometer

    NASA Astrophysics Data System (ADS)

    Frolov, S. V.; Sindeev, S. V.; Liepsch, D.; Balasso, A.; Proskurin, S. G.; Potlov, A. Y.

    2015-03-01

    It is proposed an integrated approach to the study of basilar artery blood flow using 3D laser Doppler anemometer for identifying the causes of the formation and development of cerebral aneurysms. Feature of the work is the combined usage of both mathematical modeling and experimental methods. Described the experimental setup and the method of measurement of basilar artery blood flow, carried out in an interdisciplinary laboratory of Hospital Rechts der Isar of Technical University of Munich. The experimental setup used to simulate the blood flow in the basilar artery and to measure blood flow characteristics using 3D laser Doppler anemometer (3D LDA). Described a method of numerical studies carried out in Tambov State Technical University and the Bakoulev Center for Cardiovascular Surgery. Proposed an approach for sharing experimental and numerical methods of research to identify the causes of the basilar artery aneurysms.

  3. Laser micromachining of through via interconnects in active die for 3-D multichip module

    SciTech Connect

    Chu, D.; Miller, W.D.

    1995-09-01

    One method to increase density in integrated circuits (IC) is to stack die to create a 3-D multichip module (MCM). In the past, special post wafer processing was done to bring interconnects out to the edge of the die. The die were sawed, glued, and stacked. Special processing was done to create interconnects on the edge to provide for interconnects to each of the die. These processes require an IC type fabrication facility (fab) and special processing equipment. In contrast, we have developed packaging assembly methods to created vertical through vias in bond pads of active silicon die, isolate these vias, and metal fill these vias without the use of a special IC fab. These die with through vias can then be joined and stacked to create a 3-D MCM. Vertical through vias in active die are created by laser micromachining using a Nd:YAG laser. Besides the fundamental 1064 nm (infra-red) laser wavelength of a Nd:YAG laser, modifications to our Nd:YAG laser allowed us to generate the second harmonic 532 nm (green) laser wavelength and fourth harmonic 266nm (ultra violet) laser wavelength in laser micromachining for these vias. Experiments were conducted to determine the best laser wavelengths to use for laser micromachining of vertical through vias in order to minimize damage to the active die. Via isolation experiments were done in order to determine the best method in isolating the bond pads of the die. Die thinning techniques were developed to allow for die thickness as thin as 50 {mu}m. This would allow for high 3-D density when the die are stacked. A method was developed to metal fill the vias with solder using a wire bonder with solder wire.

  4. Studies on the dynamics of vacuum encapsulated 2D MEMS scanners by laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Janes, Joachim; Hofmann, Ulrich

    2014-03-01

    2D MEMS scanners are used for e.g. Laser projection purposes or Lidar applications. Electrostatically driven resonant torsional oscillations of both axes of the scanners lead to Lissajous trajectories for Laser beams reflected from the micro mirror. Wafer level vacuum encapsulation with tilt glass capping ensures high angular amplitudes at low driving voltages additionally preventing environmental impacts. Applying Laser Doppler Vibrometry, the effect of residual gas friction, squeezed film damping and internal friction on 2D MEMS scanners is analyzed by measuring the Q-values associated with the torsional oscillations. Vibrometry is also used to analyze the oscillatory motion of the micro mirror and the gimbal of the scanners. Excited modes of the scanner structures are identified giving rise to coupling effects influencing the scanning performance of the 2D MEMS mirrors.

  5. 3D Laser Scanning Modeling and Application on Dazu Thousand-hand Bodhisattva in China

    NASA Astrophysics Data System (ADS)

    Hou, M.; Zhang, X.; Wu, Y.; Hu, Y.

    2014-04-01

    The Dazu Thousand-hand Bodhisattva Statue is located at Baoding Mountain in Chongqing. It has the reputation as "the Gem of World's Rock Carving Art". At present,the Dazu Thousand-hand Bodhisattva Statue is basically well conserved, while the local damage is already very serious. However, the Dazu Thousand-hand Bodhisattva Statue is a three-dimensional caved statue, the present plane surveying and mapping device cannot reflect the preservation situation completely. Therefore, the documentation of the Dazu Thousand-hand Bodhisattva Statue using terrestrial laser scanning is of great significance. This paper will introduce a new method for superfine 3D modeling of Thousand-hand Bodhisattva based on the high-resolution 3D cloud points. By analyzing these 3D cloud points and 3D models, some useful information, such as several 3D statistics, 3D thematic map and 3D shape restoration suggestion of Thousand-hand Bodhisattva will be revealed, which are beneficial to restoration work and some other application.

  6. Sensor fusion of cameras and a laser for city-scale 3D reconstruction.

    PubMed

    Bok, Yunsu; Choi, Dong-Geol; Kweon, In So

    2014-01-01

    This paper presents a sensor fusion system of cameras and a 2D laser sensorfor large-scale 3D reconstruction. The proposed system is designed to capture data on afast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor,and they are synchronized by a hardware trigger. Reconstruction of 3D structures is doneby estimating frame-by-frame motion and accumulating vertical laser scans, as in previousworks. However, our approach does not assume near 2D motion, but estimates free motion(including absolute scale) in 3D space using both laser data and image features. In orderto avoid the degeneration associated with typical three-point algorithms, we present a newalgorithm that selects 3D points from two frames captured by multiple cameras. The problemof error accumulation is solved by loop closing, not by GPS. The experimental resultsshow that the estimated path is successfully overlaid on the satellite images, such that thereconstruction result is very accurate. PMID:25375758

  7. Experimental investigation of 3D scanheads for laser micro-processing

    NASA Astrophysics Data System (ADS)

    Penchev, Pavel; Dimov, Stefan; Bhaduri, Debajyoti

    2016-07-01

    The broader use of laser micro-processing technology increases the demand for executing complex machining and joining operations on free-from (3D) workpieces. To satisfy these growing requirements it is necessary to utilise 3D scanheads that integrate beam deflectors (X and Y optical axes) and Z modules with high dynamics. The research presented in this communication proposes an experimental technique to quantify the dynamic capabilities of Z modules, also called Dynamic Focusing Modules (DFM), of such 3D scanheads that are essential for efficient, accurate and repeatable laser micro-processing of free form surfaces. The proposed experimental technique is validated on state-of-art laser micro-machining platform and the results show that the DFM dynamic capabilities are substantially inferior than those of X and Y beam deflectors, in particular the maximum speed of the Z module is less than 10% of the maximum speeds achievable with X and Y optical axes of the scanhead. Thus, the DFM dynamics deficiencies can become a major obstacle for the broader use of high frequency laser sources that necessitate high dynamics 3D scanheads for executing cost effectively free-form surface processing operations.

  8. Sensor Fusion of Cameras and a Laser for City-Scale 3D Reconstruction

    PubMed Central

    Bok, Yunsu; Choi, Dong-Geol; Kweon, In So

    2014-01-01

    This paper presents a sensor fusion system of cameras and a 2D laser sensor for large-scale 3D reconstruction. The proposed system is designed to capture data on a fast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor, and they are synchronized by a hardware trigger. Reconstruction of 3D structures is done by estimating frame-by-frame motion and accumulating vertical laser scans, as in previous works. However, our approach does not assume near 2D motion, but estimates free motion (including absolute scale) in 3D space using both laser data and image features. In order to avoid the degeneration associated with typical three-point algorithms, we present a new algorithm that selects 3D points from two frames captured by multiple cameras. The problem of error accumulation is solved by loop closing, not by GPS. The experimental results show that the estimated path is successfully overlaid on the satellite images, such that the reconstruction result is very accurate. PMID:25375758

  9. Deformation of ultra-short laser pulses by optical systems for laser scanners.

    PubMed

    Büsing, Lasse; Bonhoff, Tobias; Gottmann, Jens; Loosen, Peter

    2013-10-21

    Current experiments of processing glass with ultra-short laser pulses (< 1 ps) lead to scan angle depending processing results. This scan angle depending effect is examined by simulations of a common focusing lens for laser scanners. Due to dispersion, focusing lenses may cause pulse deformations and increase the pulse duration in the focal region. If the field angle of the incoming laser beam is variable, the pulse deformation may also vary as a function of the field angle. By ray tracing as well as wave optical simulations we investigate pulse deformations of optical systems for different scan angles. PMID:24150292

  10. High-resolution 3D imaging laser radar flight test experiments

    NASA Astrophysics Data System (ADS)

    Marino, Richard M.; Davis, W. R.; Rich, G. C.; McLaughlin, J. L.; Lee, E. I.; Stanley, B. M.; Burnside, J. W.; Rowe, G. S.; Hatch, R. E.; Square, T. E.; Skelly, L. J.; O'Brien, M.; Vasile, A.; Heinrichs, R. M.

    2005-05-01

    Situation awareness and accurate Target Identification (TID) are critical requirements for successful battle management. Ground vehicles can be detected, tracked, and in some cases imaged using airborne or space-borne microwave radar. Obscurants such as camouflage net and/or tree canopy foliage can degrade the performance of such radars. Foliage can be penetrated with long wavelength microwave radar, but generally at the expense of imaging resolution. The goals of the DARPA Jigsaw program include the development and demonstration of high-resolution 3-D imaging laser radar (ladar) ensor technology and systems that can be used from airborne platforms to image and identify military ground vehicles that may be hiding under camouflage or foliage such as tree canopy. With DARPA support, MIT Lincoln Laboratory has developed a rugged and compact 3-D imaging ladar system that has successfully demonstrated the feasibility and utility of this application. The sensor system has been integrated into a UH-1 helicopter for winter and summer flight campaigns. The sensor operates day or night and produces high-resolution 3-D spatial images using short laser pulses and a focal plane array of Geiger-mode avalanche photo-diode (APD) detectors with independent digital time-of-flight counting circuits at each pixel. The sensor technology includes Lincoln Laboratory developments of the microchip laser and novel focal plane arrays. The microchip laser is a passively Q-switched solid-state frequency-doubled Nd:YAG laser transmitting short laser pulses (300 ps FWHM) at 16 kilohertz pulse rate and at 532 nm wavelength. The single photon detection efficiency has been measured to be > 20 % using these 32x32 Silicon Geiger-mode APDs at room temperature. The APD saturates while providing a gain of typically > 106. The pulse out of the detector is used to stop a 500 MHz digital clock register integrated within the focal-plane array at each pixel. Using the detector in this binary response mode

  11. Rapid 3D video/laser sensing and digital archiving with immediate on-scene feedback for 3D crime scene/mass disaster data collection and reconstruction

    NASA Astrophysics Data System (ADS)

    Altschuler, Bruce R.; Oliver, William R.; Altschuler, Martin D.

    1996-02-01

    We describe a system for rapid and convenient video data acquisition and 3-D numerical coordinate data calculation able to provide precise 3-D topographical maps and 3-D archival data sufficient to reconstruct a 3-D virtual reality display of a crime scene or mass disaster area. Under a joint U.S. army/U.S. Air Force project with collateral U.S. Navy support, to create a 3-D surgical robotic inspection device -- a mobile, multi-sensor robotic surgical assistant to aid the surgeon in diagnosis, continual surveillance of patient condition, and robotic surgical telemedicine of combat casualties -- the technology is being perfected for remote, non-destructive, quantitative 3-D mapping of objects of varied sizes. This technology is being advanced with hyper-speed parallel video technology and compact, very fast laser electro-optics, such that the acquisition of 3-D surface map data will shortly be acquired within the time frame of conventional 2-D video. With simple field-capable calibration, and mobile or portable platforms, the crime scene investigator could set up and survey the entire crime scene, or portions of it at high resolution, with almost the simplicity and speed of video or still photography. The survey apparatus would record relative position, location, and instantly archive thousands of artifacts at the site with 3-D data points capable of creating unbiased virtual reality reconstructions, or actual physical replicas, for the investigators, prosecutors, and jury.

  12. 3D camera assisted fully automated calibration of scanning laser Doppler vibrometers

    NASA Astrophysics Data System (ADS)

    Sels, Seppe; Ribbens, Bart; Mertens, Luc; Vanlanduit, Steve

    2016-06-01

    Scanning laser Doppler vibrometers (LDV) are used to measure full-field vibration shapes of products and structures. In most commercially available scanning laser Doppler vibrometer systems the user manually draws a grid of measurement locations on a 2D camera image of the product. The determination of the correct physical measurement locations can be a time consuming and diffcult task. In this paper we present a new methodology for product testing and quality control that integrates 3D imaging techniques with vibration measurements. This procedure allows to test prototypes in a shorter period because physical measurements locations will be located automatically. The proposed methodology uses a 3D time-of-flight camera to measure the location and orientation of the test-object. The 3D image of the time-of-flight camera is then matched with the 3D-CAD model of the object in which measurement locations are pre-defined. A time of flight camera operates strictly in the near infrared spectrum. To improve the signal to noise ratio in the time-of-flight measurement, a time-of-flight camera uses a band filter. As a result of this filter, the laser spot of most laser vibrometers is invisible in the time-of-flight image. Therefore a 2D RGB-camera is used to find the laser-spot of the vibrometer. The laser spot is matched to the 3D image obtained by the time-of-flight camera. Next an automatic calibration procedure is used to aim the laser at the (pre)defined locations. Another benefit from this methodology is that it incorporates automatic mapping between a CAD model and the vibration measurements. This mapping can be used to visualize measurements directly on a 3D CAD model. Secondly the orientation of the CAD model is known with respect to the laser beam. This information can be used to find the direction of the measured vibration relatively to the surface of the object. With this direction, the vibration measurements can be compared more precisely with numerical

  13. Iso-sciatic point: novel approach to distinguish shadowing 3-D mask effects from scanner aberrations in extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Leunissen, Leonardus H. A.; Gronheid, Roel; Gao, Weimin

    2006-06-01

    Extreme ultraviolet lithography (EUVL) uses a reflective mask with a multilayer coating. Therefore, the illumination is an off-axis ring field system that is non-telecentric on the mask side. This non-zero angle of incidence combined with the three-dimensional mask topography results in the so-called "shadowing effect". The shadowing causes the printed CD to depend on the orientation as well as on the position in the slit and it will significantly influence the image formation [1,2]. In addition, simulations show that the Bossung curves are asymmetrical due to 3-D mask effects and their best focus depends on the shadowing angle [3]. Such tilts in the Bossung curves are usually associated with aberrations in the optical system. In this paper, we describe an approach in which both properties can be disentangled. Bossung curve simulations with varying effective angles of incidence (between 0 and 6 degrees) show that at discrete defocus offsets, the printed linewidth is independent of the incident angle (and thus independent of the shadowing effect), the so-called iso-sciatic (constant shadowing) point. For an ideal optical system this means that the size of a printed feature with a given mask-CD and orientation does not change through slit. With a suitable test structure it is possible to use this effect to distinguish between mask topography and imaging effects from aberrations through slit. Simulations for the following aberrations tested the approach: spherical, coma and astigmatism.

  14. Preliminary study of statistical pattern recognition-based coin counterfeit detection by means of high resolution 3D scanners

    NASA Astrophysics Data System (ADS)

    Leich, Marcus; Kiltz, Stefan; Krätzer, Christian; Dittmann, Jana; Vielhauer, Claus

    2011-03-01

    According to the European Commission around 200,000 counterfeit Euro coins are removed from circulation every year. While approaches exist to automatically detect these coins, satisfying error rates are usually only reached for low quality forgeries, so-called "local classes". High-quality minted forgeries ("common classes") pose a problem for these methods as well as for trained humans. This paper presents a first approach for statistical analysis of coins based on high resolution 3D data acquired with a chromatic white light sensor. The goal of this analysis is to determine whether two coins are of common origin. The test set for these first and new investigations consists of 62 coins from not more than five different sources. The analysis is based on the assumption that, apart from markings caused by wear such as scratches and residue consisting of grease and dust, coins from equal origin have a more similar height field than coins from different mints. First results suggest that the selected approach is heavily affected by influences of wear like dents and scratches and the further research is required the eliminate this influence. A course for future work is outlined.

  15. Inscription of 3D waveguides in diamond using an ultrafast laser

    NASA Astrophysics Data System (ADS)

    Courvoisier, Arnaud; Booth, Martin J.; Salter, Patrick S.

    2016-07-01

    Three dimensional waveguides within the bulk of diamond are manufactured using ultrafast laser fabrication. High intensities within the focal volume of the laser cause breakdown of the diamond into a graphitic phase leading to a stress induced refractive index change in neighboring regions. Type II waveguiding is thus enabled between two adjacent graphitic tracks, but supporting just a single polarization state. We show that adaptive aberration correction during the laser processing allows the controlled fabrication of more complex structures beneath the surface of the diamond which can be used for 3D waveguide splitters and Type III waveguides which support both polarizations.

  16. 3D Modeling of Laser Propagation in Ionizing Gas and Plasma

    NASA Astrophysics Data System (ADS)

    Cooley, J.; Antonsen, T., Jr.; Huang, C.; Mori, W.

    2003-10-01

    The interaction of a high intensity laser with ionizing gas and plasmas is of current interest for both Laser Wakefield Accelerators and x-ray generation. We have developed a 3D fluid simulation code based on the same quasistatic approximation used in the 2D code WAKE [1]. The object oriented structure of the code also allows it to couple to the quickPIC particle code [2]. We will present 3D studies of the ionization scattering instability [3], which occurs when a laser pulse propagates in an ionizing gas. [1] P. Mora and T. Antonsen, Jr., Phys. Plasmas 4(1), January 1997 [2] J. Cooley, T. Antonsen, Jr., C. Huang, etal., Proceedings, Advanced Accelerator Concepts, 2002 [3] Z. Bian and T. Antonsen, Jr., Phys. Plasmas 8(7), July 2001 * work supported by NSF and DOE

  17. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    PubMed

    Wouterlood, Floris G

    2014-01-01

    A confocal laser scanning microscope (CLSM) collects information from a thin, focal plane and ignores out-of-focus information. Scanning of a specimen, with stepwise axial (Z-) movement of the stage in between each scan, produces Z-series of confocal images of a tissue volume, which then can be used to 3-D reconstruct structures of interest. The operator first configures separate channels (e.g., laser, filters, and detector settings) for each applied fluorochrome and then acquires Z-series of confocal images: one series per channel. Channel signal separation is extremely important. Measures to avoid bleaching are vital. Post-acquisition deconvolution of the image series is often performed to increase resolution before 3-D reconstruction takes place. In the 3-D reconstruction programs described in this unit, reconstructions can be inspected in real time from any viewing angle. By altering viewing angles and by switching channels off and on, the spatial relationships of 3-D-reconstructed structures with respect to structures visualized in other channels can be studied. Since each brand of CLSM, computer program, and 3-D reconstruction package has its own proprietary set of procedures, a general approach is provided in this protocol wherever possible. PMID:24723320

  18. Femtosecond laser 3D nanofabrication in glass: enabling direct write of integrated micro/nanofluidic chips

    NASA Astrophysics Data System (ADS)

    Cheng, Ya; Liao, Yang; Sugioka, Koji

    2014-03-01

    The creation of complex three-dimensional (3D) fluidic systems composed of hollow micro- and nanostructures embedded in transparent substrates has attracted significant attention from both scientific and applied research communities. However, it is by now still a formidable challenge to build 3D micro- and nanofluidic structures with arbitrary configurations using conventional planar lithographic fabrication methods. As a direct and maskless fabrication technique, femtosecond laser micromachining provides a straightforward approach for high-precision spatial-selective modification inside transparent materials through nonlinear optical absorption. Here, we demonstrate rapid fabrication of high-aspect-ratio micro- and/or nanofluidic structures with various 3D configurations in glass substrates by femtosecond laser direct writing. Based on this approach, we demonstrate several functional micro- and nanofluidic devices including a 3D passive microfluidic mixer, a capillary electrophoresis (CE) analysis chip, and an integrated micro-nanofluidic system for single DNA analysis. This technology offers new opportunities to develop novel 3D micro-nanofluidic systems for a variety of lab-on-a-chip applications.

  19. TU-C-BRE-04: 3D Gel Dosimetry Using ViewRay On-Board MR Scanner: A Feasibility Study

    SciTech Connect

    Zhang, L; Du, D; Green, O; Rodriguez, V; Wooten, H; Xiao, Z; Yang, D; Hu, Y; Li, H

    2014-06-15

    Purpose: MR based 3D gel has been proposed for radiation therapy dosimetry. However, access to MR scanner has been one of the limiting factors for its wide acceptance. Recent commercialization of an on-board MR-IGRT device (ViewRay) may render the availability issue less of a concern. This work reports our attempts to simulate MR based dose measurement accuracy on ViewRay using three different gels. Methods: A spherical BANG gel dosimeter was purchased from MGS Research. Cylindrical MAGIC gel and Fricke gel were fabricated in-house according to published recipes. After irradiation, BANG and MAGIC were imaged using a dual-echo spin echo sequence for T2 measurement on a Philips 1.5T MR scanner, while Fricke gel was imaged using multiple spin echo sequences. Difference between MR measured and TPS calculated dose was defined as noise. The noise power spectrum was calculated and then simulated for the 0.35 T magnetic field associated with ViewRay. The estimated noise was then added to TG-119 test cases to simulate measured dose distributions. Simulated measurements were evaluated against TPS calculated doses using gamma analysis. Results: Given same gel, sequence and coil setup, with a FOV of 180×90×90 mm3, resolution of 3×3×3 mm3, and scanning time of 30 minutes, the simulated measured dose distribution using BANG would have a gamma passing rate greater than 90% (3%/3mm and absolute). With a FOV 180×90×90 mm3, resolution of 4×4×5 mm3, and scanning time of 45 minutes, the simulated measuremened dose distribution would have a gamma passing rate greater than 97%. MAGIC exhibited similar performance while Fricke gel was inferior due to much higher noise. Conclusions: The simulation results demonstrated that it may be feasible to use MAGIC and BANG gels for 3D dose verification using ViewRay low-field on-board MRI scanner.

  20. Femtosecond fiber laser additive manufacturing and welding for 3D manufacturing

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Nie, Bai; Wan, Peng; Yang, Lih-Mei; Bai, Shuang; Liu, Jian

    2015-03-01

    Due to the unique ultra-short pulse duration and high peak power, femtosecond (fs) laser has emerged as a powerful tool for many applications but has rarely been studied for 3D printing. In this paper, welding of both bulk and powder materials is demonstrated for the first time by using high energy and high repetition rate fs fiber lasers. It opens up new scenarios and opportunities for 3D printing with the following advantages - greater range of materials especially with high melting temperature, greater-than-ever level of precision (sub-micron) and less heat-affected-zone (HAZ). Mechanical properties (strength and hardness) and micro-structures (grain size) of the fabricated parts are investigated. For dissimilar materials bulk welding, good welding quality with over 210 MPa tensile strength is obtained. Also full melting of the micron-sized refractory powders with high melting temperature (above 3000 degree C) is achieved for the first time. 3D parts with shapes like ring and cube are fabricated. Not only does this study explore the feasibility of melting dissimilar and high melting temperature materials using fs lasers, but it also lays out a solid foundation for 3D printing of complex structure with designed compositions, microstructures and properties. This can greatly benefit the applications in automobile, aerospace and biomedical industries, by producing parts like nozzles, engines and miniaturized biomedical devices.

  1. Reference Value Provision Schemes for Attenuation Correction of Full-Waveform Airborne Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    Richter, K.; Blaskow, R.; Stelling, N.; Maas, H.-G.

    2015-08-01

    The characterization of the vertical forest structure is highly relevant for ecological research and for better understanding forest ecosystems. Full-waveform airborne laser scanner systems providing a complete time-resolved digitization of every laser pulse echo may deliver very valuable information on the biophysical structure in forest stands. To exploit the great potential offered by full-waveform airborne laser scanning data, the development of suitable voxel based data analysis methods is straightforward. Beyond extracting additional 3D points, it is very promising to derive voxel attributes from the digitized waveform directly. However, the 'history' of each laser pulse echo is characterized by attenuation effects caused by reflections in higher regions of the crown. As a result, the received waveform signals within the canopy have a lower amplitude than it would be observed for an identical structure without the previous canopy structure interactions (Romanczyk et al., 2012). To achieve a radiometrically correct voxel space representation, the loss of signal strength caused by partial reflections on the path of a laser pulse through the canopy has to be compensated by applying suitable attenuation correction models. The basic idea of the correction procedure is to enhance the waveform intensity values in lower parts of the canopy for portions of the pulse intensity, which have been reflected in higher parts of the canopy. To estimate the enhancement factor an appropriate reference value has to be derived from the data itself. Based on pulse history correction schemes presented in previous publications, the paper will discuss several approaches for reference value estimation. Furthermore, the results of experiments with two different data sets (leaf-on/leaf-off) are presented.

  2. Printing of metallic 3D micro-objects by laser induced forward transfer.

    PubMed

    Zenou, Michael; Kotler, Zvi

    2016-01-25

    Digital printing of 3D metal micro-structures by laser induced forward transfer under ambient conditions is reviewed. Recent progress has allowed drop on demand transfer of molten, femto-liter, metal droplets with a high jetting directionality. Such small volume droplets solidify instantly, on a nanosecond time scale, as they touch the substrate. This fast solidification limits their lateral spreading and allows the fabrication of high aspect ratio and complex 3D metal structures. Several examples of micron-scale resolution metal objects printed using this method are presented and discussed. PMID:26832524

  3. Development of Kinematic 3D Laser Scanning System for Indoor Mapping and As-Built BIM Using Constrained SLAM

    PubMed Central

    Jung, Jaehoon; Yoon, Sanghyun; Ju, Sungha; Heo, Joon

    2015-01-01

    The growing interest and use of indoor mapping is driving a demand for improved data-acquisition facility, efficiency and productivity in the era of the Building Information Model (BIM). The conventional static laser scanning method suffers from some limitations on its operability in complex indoor environments, due to the presence of occlusions. Full scanning of indoor spaces without loss of information requires that surveyors change the scanner position many times, which incurs extra work for registration of each scanned point cloud. Alternatively, a kinematic 3D laser scanning system, proposed herein, uses line-feature-based Simultaneous Localization and Mapping (SLAM) technique for continuous mapping. Moreover, to reduce the uncertainty of line-feature extraction, we incorporated constrained adjustment based on an assumption made with respect to typical indoor environments: that the main structures are formed of parallel or orthogonal line features. The superiority of the proposed constrained adjustment is its reduction for uncertainties of the adjusted lines, leading to successful data association process. In the present study, kinematic scanning with and without constrained adjustment were comparatively evaluated in two test sites, and the results confirmed the effectiveness of the proposed system. The accuracy of the 3D mapping result was additionally evaluated by comparison with the reference points acquired by a total station: the Euclidean average distance error was 0.034 m for the seminar room and 0.043 m for the corridor, which satisfied the error tolerance for point cloud acquisition (0.051 m) according to the guidelines of the General Services Administration for BIM accuracy. PMID:26501292

  4. Development of kinematic 3D laser scanning system for indoor mapping and as-built BIM using constrained SLAM.

    PubMed

    Jung, Jaehoon; Yoon, Sanghyun; Ju, Sungha; Heo, Joon

    2015-01-01

    The growing interest and use of indoor mapping is driving a demand for improved data-acquisition facility, efficiency and productivity in the era of the Building Information Model (BIM). The conventional static laser scanning method suffers from some limitations on its operability in complex indoor environments, due to the presence of occlusions. Full scanning of indoor spaces without loss of information requires that surveyors change the scanner position many times, which incurs extra work for registration of each scanned point cloud. Alternatively, a kinematic 3D laser scanning system, proposed herein, uses line-feature-based Simultaneous Localization and Mapping (SLAM) technique for continuous mapping. Moreover, to reduce the uncertainty of line-feature extraction, we incorporated constrained adjustment based on an assumption made with respect to typical indoor environments: that the main structures are formed of parallel or orthogonal line features. The superiority of the proposed constrained adjustment is its reduction for uncertainties of the adjusted lines, leading to successful data association process. In the present study, kinematic scanning with and without constrained adjustment were comparatively evaluated in two test sites, and the results confirmed the effectiveness of the proposed system. The accuracy of the 3D mapping result was additionally evaluated by comparison with the reference points acquired by a total station: the Euclidean average distance error was 0.034 m for the seminar room and 0.043 m for the corridor, which satisfied the error tolerance for point cloud acquisition (0.051 m) according to the guidelines of the General Services Administration for BIM accuracy. PMID:26501292

  5. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, R.A.; Peck, K.

    1992-02-25

    A fluorescent scanner is designed for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier. The scanner includes a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from the volume to provide a display of the separated sample. 8 figs.

  6. Relativistic Laser Pulse Intensification with 3D Printed Micro-Tube Plasma Target

    NASA Astrophysics Data System (ADS)

    Ji, Liangliang; Snyder, Joseph; Pukhov, Alexander; Akli, Kramer

    2015-11-01

    The potential and applications of laser-plasma interactions (LPI) are restricted by the parameter space of existing lasers and targets. Advancing the laser intensity to the extreme regime is motivated by the production of energetic particle beams and by the quest to explore the exotic regimes of light-matter interaction. Target density and dimensions can always be varied to optimize the outcome. Here, we propose to create another degree of freedom in the parameter space of LPI using recent advances in 3D printing of materials. Fine structures at nm scale with high repetition and accuracy can nowadays be manufactured, allowing for a full precise control of the target. We demonstrate, via particle-in-cell (PIC) simulations, that 3D-printed micro-tube plasma (MTP) targets yield an intensity enhancement factor of 2-5. The novel MTP targets not only act as a plasma optical device to reach the 1023W/cm2 threshold based on today's intensities, but can also boost the generation of secondary particle and radiation sources. This work demonstrates that the combination of high contrast high power lasers and nano-3D printing techniques opens new paths in the intensity frontier and LPI micro-engineering.

  7. Real-time tracking of objects for space applications using a laser range scanner

    NASA Technical Reports Server (NTRS)

    Blais, F.; Couvillon, R. A.; Rioux, M.; Maclean, S. G.

    1994-01-01

    Real-time tracking of multiple targets and three dimensional object features was demonstrated using a laser range scanner. The prototype was immune to ambient illumination and sun interference. Tracking error feedback was simultaneously obtained from individual targets, global predicted target position, and the human operator. A more complete study of calibration parameters and temperature variations on the scanner is needed to determine the exact performance of the sensor. Lissajous patterns used in three-dimensional real-time tracking prove helpful given their high resolution. The photogrammetry-based Advanced Space Vision System (ASVS) is discussed in combination with the laser range scanner.

  8. Post-processing of 3D-printed parts using femtosecond and picosecond laser radiation

    NASA Astrophysics Data System (ADS)

    Mingareev, Ilya; Gehlich, Nils; Bonhoff, Tobias; Meiners, Wilhelm; Kelbassa, Ingomar; Biermann, Tim; Richardson, Martin C.

    2014-03-01

    Additive manufacturing, also known as 3D-printing, is a near-net shape manufacturing approach, delivering part geometry that can be considerably affected by various process conditions, heat-induced distortions, solidified melt droplets, partially fused powders, and surface modifications induced by the manufacturing tool motion and processing strategy. High-repetition rate femtosecond and picosecond laser radiation was utilized to improve surface quality of metal parts manufactured by laser additive techniques. Different laser scanning approaches were utilized to increase the ablation efficiency and to reduce the surface roughness while preserving the initial part geometry. We studied post-processing of 3D-shaped parts made of Nickel- and Titanium-base alloys by utilizing Selective Laser Melting (SLM) and Laser Metal Deposition (LMD) as additive manufacturing techniques. Process parameters such as the pulse energy, the number of layers and their spatial separation were varied. Surface processing in several layers was necessary to remove the excessive material, such as individual powder particles, and to reduce the average surface roughness from asdeposited 22-45 μm to a few microns. Due to the ultrafast laser-processing regime and the small heat-affected zone induced in materials, this novel integrated manufacturing approach can be used to post-process parts made of thermally and mechanically sensitive materials, and to attain complex designed shapes with micrometer precision.

  9. Comparison of working efficiency of terrestrial laser scanner in day and night conditions

    NASA Astrophysics Data System (ADS)

    Arslan, A. E.; Kalkan, K.

    2013-10-01

    Terrestrial Laser Scanning is a popular and widely used technique to scan existing objects, document historical sites and items, and remodel them if and when needed. Their ability to collect thousands of point data per second makes them an invaluable tool in many areas from engineering to historical reconstruction. There are many scanners in the market with different technical specifications. One main technical specification of laser scanners is range and illumination. In this study, it is tested to be determined the optimal working times of a laser scanner and the scanners consistency with its specifications sheet. In order to conduct this work, series of GNSS measurements in Istanbul Technical University have been carried out, connected to the national reference network, to determine precise positions of target points and the scanner, which makes possible to define a precise distance between the scanner and targets. Those ground surveys has been used for calibration and registration purposes. Two different scan campaigns conducted at 12 am and 11 pm to compare working efficiency of laser scanner in different illumination conditions and targets are measured with a handheld spectro-radiometer in order to determine their reflective characteristics. The obtained results are compared and their accuracies have been analysed.

  10. Laser jetting of femto-liter metal droplets for high resolution 3D printed structures

    PubMed Central

    Zenou, M.; Sa’ar, A.; Kotler, Z.

    2015-01-01

    Laser induced forward transfer (LIFT) is employed in a special, high accuracy jetting regime, by adequately matching the sub-nanosecond pulse duration to the metal donor layer thickness. Under such conditions, an effective solid nozzle is formed, providing stability and directionality to the femto-liter droplets which are printed from a large gap in excess of 400 μm. We illustrate the wide applicability of this method by printing several 3D metal objects. First, very high aspect ratio (A/R > 20), micron scale, copper pillars in various configuration, upright and arbitrarily bent, then a micron scale 3D object composed of gold and copper. Such a digital printing method could serve the generation of complex, multi-material, micron-scale, 3D materials and novel structures. PMID:26602432