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Sample records for histology-equivalent sectioning laser-scanning

  1. Multicolor immunophenotyping of tissue sections by laser scanning cytometry (LSC)

    NASA Astrophysics Data System (ADS)

    Tarnok, Attila; Gerstner, Andreas O.; Lenz, Dominik; Osmancik, Pavel; Schneider, Peter; Trumpfheller, Christine; Racz, Pal; Tenner-Racz, Klara

    2002-05-01

    In lymphatic organs the quantitative analysis of the spatial distribution of leukocytes would give relevant information about alterations during diseases (leukemia, HIV, AIDS) and their therapeutic regimen. Analysis of them in solid tissues is difficult to perform but would yield important data in a variety of clinical and experimental settings. We have developed an automated analysis method for LSC suitable for archived or fresh biopsy material of human lymph nodes and tonsils. Sections are stained with PI for DNA and up to three antigens using direct or indirect immunofluorescence staining. Measurement is triggered on DNA-fluorescence (Argon Laser). Due to the heterogeneity in cell density measurements are repeatedly performed at different threshold levels (low threshold: regions of low cellular density, germinal centers; high threshold: dense regions, mantle zone). Data are acquired by single- (Ar) or dual-laser excitation (Ar-HeNe) in order to determine data from single- (FITC), up to triple-staining (FITC/PE-Cy5/APC). Percentage and cellular density of cell-subsets is quantified in different structural regions of the specimen. Comparison with manual analysis of identical specimens showed very good correlation. With LSC a semi-automated operator-independent and immunophenotyping of lymphatic tissues with simultaneously up to four antibodies is possible. This technique should yield new insight into processes during diseases and should help to quantify the success of therapeutic interventions.

  2. Laser scanning confocal microscopy: history, applications, and related optical sectioning techniques.

    PubMed

    Paddock, Stephen W; Eliceiri, Kevin W

    2014-01-01

    Confocal microscopy is an established light microscopical technique for imaging fluorescently labeled specimens with significant three-dimensional structure. Applications of confocal microscopy in the biomedical sciences include the imaging of the spatial distribution of macromolecules in either fixed or living cells, the automated collection of 3D data, the imaging of multiple labeled specimens and the measurement of physiological events in living cells. The laser scanning confocal microscope continues to be chosen for most routine work although a number of instruments have been developed for more specific applications. Significant improvements have been made to all areas of the confocal approach, not only to the instruments themselves, but also to the protocols of specimen preparation, to the analysis, the display, the reproduction, sharing and management of confocal images using bioinformatics techniques. PMID:24052346

  3. Comparison of human colorectal normal tissue with cancerous tissue autofluorescence image by optical sectioning with a confocal laser-scanning microscope

    NASA Astrophysics Data System (ADS)

    Fu, Sheng; Chia, Teck-Chee; Kwek, Leong Chuan; Diong, Cheong Hoong; Tang, Choong Leong; Choen, Francis S.; Krishnan, Shankar M.

    2003-10-01

    We investigated normal and cancerous human colorectal tissues (fresh thick biopsy specimens) using Olympus Confocal laser scanning biological microscope (FV300). The different layers of autofluorescence images of the specimen were captured by 488 nm laser scanning and sectioning. Optical sectioning can be performed in the vertical plane. Laser scanning can be performed in the horizontal plane. By comparing the autofluorescence image of the normal colorectal tissue with cancerous tissue, the structures of the optical sectioning image layer were found to be significantly different. We have also obtained fibrous autofluorescence image inside tissue specimen. Our investigation may help provide some useful insight to other autofluorescence research studies like laser induced autofluorescence spectra of human colorectal tissue study as a diagnosis technique for clinical application.

  4. Laser Scanning Cytometry

    PubMed Central

    Pozarowski, Piotr; Holden, Elena; Darzynkiewicz, Zbigniew

    2013-01-01

    Summary The laser scanning cytometer (LSC) is the microscope-based cytofluorometer that offers a plethora of analytical capabilities. Multilaser-excited fluorescence emitted from individual cells is measured at several wavelength ranges, rapidly (up to 5000 cells/min), with high sensitivity and accuracy. The following applications of LSC are reviewed: (1) identification of cells that differ in degree of chromatin condensation (e.g., mitotic or apoptotic cells or lymphocytes vs granulocytes vs monocytes); (2) detection of translocation between cytoplasm vs nucleus or nucleoplasm vs nucleolus of regulatory molecules such as NF- κB, p53, or Bax; (3) semiautomatic scoring of micronuclei in mutagenicity assays; (4) analysis of fluorescence in situ hybridization; (5) enumeration and morphometry of nucleoli; (6) analysis of phenotype of progeny of individual cells in clonogenicity assay; (7) cell immunophenotyping; (8) visual examination, imaging, or sequential analysis of the cells measured earlier upon their relocation, using different probes; (9) in situ enzyme kinetics and other time-resolved processes; (10) analysis of tissue section architecture; (11) application for hypocellular samples (needle aspirate, spinal fluid, etc.); (12) other clinical applications. Advantages and limitations of LSC are discussed and compared with flow cytometry. PMID:16719355

  5. [Laser scanning in ophthalmology].

    PubMed

    Jean, B; Frohn, A; Thiel, H J

    1990-01-01

    The current state of the art for the major laser scanning methods, laser scanning ophthalmoscopy (LSO) and laser tomographic scanning (LTS) is discussed and the function principles are described. Experience with a prototype of each instrument from Rodenstock (LSO) and Heidelberg Instruments (LTS) is reported. LSO imaging of the cornea, vitreous, retina, and optic disc, as well as on-line processing is demonstrated with examples (nerve fibre colour coding and histograms). Measurement of the cornea, optic disc and retinal topography with LTS is also demonstrated with examples. An example of polarization optical imaging of the cornea's assumed interferometric "tension patterns" is shown. The current status and future possibilities of laser scanning, its expanded diagnostic potential with microperimetry, IR scanning angiography and polarization optic imaging and measurement (eg. nerve fibre thickness) is discussed extensively. The safety aspects of laser light exposure of the macula are also mentioned. Laser scanners as imaging and measuring sensors of unknown accuracy open a new area of possibly revolutionary diagnostic possibilities.

  6. In vivo imaging flow cytometry based on laser scanning two-photon microscopy at kHz cross-sectional frame rate

    NASA Astrophysics Data System (ADS)

    Kong, Lingjie; Tang, Jianyong; Cui, Meng

    2016-03-01

    In vivo flow cytometry has found numerous applications in biology and pharmacology. However, conventional cytometry does not provide the detailed morphological information that is needed to fully determine the phenotype of individual circulating cells. Imaging cytometry, capable of visualizing the morphology and dynamics of the circulating cells at high spatiotemporal resolution, is highly desired. Current wide-field based image cytometers are limited in the imaging depth and provide only two-dimensional resolution. For deep tissue imaging, laser scanning two-photon fluorescence microscopy (TPM) is widely adopted. However, for applications in flow cytometry, the axial scanning speed of current TPMs is inadequate to provide high-speed cross-sectional imaging of vasculature. We have integrated an optical phase-locked ultrasound lens into a standard TPM and achieved microsecond-scale axial scanning. With a galvo scanner for transverse scanning, we achieved kHz cross-sectional frame rate. Here we report its applications for in vivo deformability cytometry and in vivo imaging flow cytometry, and demonstrate the capability of imaging dynamical morphologies of flowing cells, distinguishing cells and cellular clusters, and simultaneously quantifying different cell populations based on their fluorescent labels.

  7. Laser Scanning Applications in Fluvial Geomorphology

    NASA Astrophysics Data System (ADS)

    Alho, P.

    2014-12-01

    During recent decades, the use of high-resolution laser scanning data in fluvial studies has rapidly increased. Airborne laser scanning (ALS) can be used to extensively map riverine topography. Laser scanning data have great potential to improve the effectiveness of topographical data acquisition and the accuracy and resolution of DTMs (Digital Terrain Models) needed in fluvial geomorphology. Airborne Laser Scanning (ALS) is applicable for mapping areas varying from reach to catchment scale and these data are, therefore, particularly suitable, especially for hydraulic modelling, mapping of flood inundation, and the detection of macro-scale fluvial geomorphology. With Terrestrial Laser Scanning (TLS) a spatial resolution of less than 1 mm and a range accuracy of few millimetres can be achieved. Mobile Laser Scanning (MLS) enables a remarkably faster survey approach compared to the conventional TLS method. One of the newest applications of MLS approaches involves a boat/cart/backpack -based mobile mapping system. This set-up includes laser scanning and imaging from a platform moving along a river course or floodplain and may be used to expand the spatial extent of terrestrial scanning. Detailed DTMs derived from laser scanning data can be used to improve the recognition of fluvial landforms, the geometric data of hydraulic modelling, and the estimation of flood inundation extents and the associated fluvial processes. Fluvial environments also offer challenges for the application of laser scanning techniques. Factors such as vegetation cover, terrain undulation, coarse surface materials and water surfaces may distort a laser scanning survey.

  8. Street-Scene Tree Segmentation from Mobile Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Guan, H.; Cao, S.; Yu, Y.; Li, J.; Liu, N.; Chen, P.; Li, Y.

    2016-06-01

    Our work addresses the problem of extracting trees from mobile laser scanning data. The work is a two step-wise strategy, including terrain point removal and tree segmentation. First, a voxel-based upward growing filtering is proposed to remove terrain points from the mobile laser scanning data. Then, a tree segmentation is presented to extract individual trees via a Euclidean distance clustering approach and Voxel-based Normalized Cut (VNCut) segmentation approach. A road section data acquired by a RIEGL VMX-450 system are selected for evaluating the proposed tree segmentation method. Qualitative analysis shows that our algorithm achieves a good performance.

  9. Selected papers on laser scanning and recording

    NASA Astrophysics Data System (ADS)

    Beiser, L.

    Previously published papers concerned with laser scanning and recording techniques are presented. Subjects treated include laser beam information scanning and recording, laser scanning techniques, system design considerations for laser scanning, laser noise, reliability, resolution, and dynamic range, and optical data storage systems. Consideration is given to the components and media for developing laser scanning and recording systems, in particular the laser, the optics, the scanner, and the storage media. Topics discussed include basic and operational multichannel acoustooptic operation; galvanometer and analog compensations; motor and control systems; angle measurement of scanner by interferometry, preheat-aided laser recording, creating multidimensional scan using a single rotating component, digital techniques in high resolution analog scanning and recording; laser scanning parameters and latitudes in laser xerography; optical video disc technology; focus error detection in optical data storage systems, holographic laser scanners for nonimpact printing; and techniques in optical strobe recording. Laser beam recording, techniques, film recorder systems, laser scanner applicaations, the optimization of printing speed and printout quality of laser beam printers, an internal drum laser scanning plate exposure system, and an ultra-high resolution graphic data terminal are described.

  10. Multiplatform Mobile Laser Scanning: Usability and Performance

    PubMed Central

    Kukko, Antero; Kaartinen, Harri; Hyyppä, Juha; Chen, Yuwei

    2012-01-01

    Mobile laser scanning is an emerging technology capable of capturing three-dimensional data from surrounding objects. With state-of-the-art sensors, the achieved point clouds capture object details with good accuracy and precision. Many of the applications involve civil engineering in urban areas, as well as traffic and other urban planning, all of which serve to make 3D city modeling probably the fastest growing market segment in this field. This article outlines multiplatform mobile laser scanning solutions such as vehicle- and trolley-operated urban area data acquisition, and boat-mounted equipment for fluvial environments. Moreover, we introduce a novel backpack version of mobile laser scanning equipment for surveying applications in the field of natural sciences where the requirements include precision and mobility in variable terrain conditions. In addition to presenting a technical description of the systems, we discuss the performance of the solutions in the light of various applications in the fields of urban mapping and modeling, fluvial geomorphology, snow-cover characterization, precision agriculture, and in monitoring the effects of climate change on permafrost landforms. The data performance of the mobile laser scanning approach is described by the results of an evaluation of the ROAMER on a permanent MLS test field. Furthermore, an in situ accuracy assessment using a field of spherical 3D targets for the newly-introduced Akhka backpack system is conducted and reported on.

  11. Laser scan microscope and infrared laser scan microcope: two important tools for device testing

    NASA Astrophysics Data System (ADS)

    Ziegler, Eberhard

    1991-03-01

    The optical beam induced current (OBIC) produced in devices by a laser scan microscope (LSM) is used to localize hot spots, leakage currents, electrostatic discharge defects and weak points. The LSM also allows photoluminescence measurements with high spatial and energy resolution. Using the infrared laser scan microscope (IR LSM), defects in the metallization and latch-up sensitive region could be detected from the back of the device.

  12. The design of laser scanning galvanometer system

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoling; Zhou, Bin; Xie, Weihao; Zhang, Yuangeng

    2015-02-01

    In this paper, we designed the laser scanning galvanometer system according to our requirements. Based on scanning range of our laser scanning galvanometer system, the design parameters of this system were optimized. During this work, we focused on the design of the f-θ field lens. An optical system of patent lens in the optical manual book, which had three glasses structure, was used in our designs. Combining the aberration theory, the aberration corrections and image quality evaluations were finished using Code V optical design software. An optimum f-θ field lens was designed, which had focal length of 434 mm, pupil diameter of 30 mm, scanning range of 160 mm × 160 mm, and half field angle of 18°×18°. At the last, we studied the influences of temperature changes on our system.

  13. Multiplatform Approach to Mobile Laser Scanning

    NASA Astrophysics Data System (ADS)

    Kukko, A.; Kaartinen, H.; Hyyppä, J.; Chen, Y.

    2012-07-01

    Mobile laser scanning is an emerging technology for capturing three-dimensional information from the surrounding objects. With state of the art sensors the achieved point cloud could capture fine details of the surroundings with good accuracy and effectiveness. Many of the applications deal with the civil engineering purposes in urban areas for traffic and city planning and modelling. In this article we present multiplatform mobile laser scanning solutions for mapping applications that require mobility in various terrains and river environments but yet produce high density point clouds with good reliability and accuracy. The ROAMER mobile laser scanning system was deployed in multitude of tasks from urban areas to climate research. The paper also introduces a completely new backpack Akhka platform for mobile lidar mapping of areas where wheeled vehicles cannot operate. The sensor set is the same in all of the approaches, but the carrying vessel was selected according to the application. This was possible thanks to a relatively light and compact yet simple design of the system. ROAMER system is one of the few high-end MLS systems that are easily adaptable to various platforms. In addition to technical description of the system we discuss the practical performance of the solutions through various applications in the fields of urban mapping, fluvial geomorphology, snow cover characterization and climate change monitoring.

  14. Photodynamic therapy with laser scanning mode of tumor irradiation

    NASA Astrophysics Data System (ADS)

    Chepurna, Oksana; Shton, Irina; Kholin, Vladimir; Voytsehovich, Valerii; Popov, Viacheslav; Pavlov, Sergii; Gamaleia, Nikolai; Wójcik, Waldemar; Zhassandykyzy, Maral

    2015-12-01

    In this study we propose a new version of photodynamic therapy performed by laser scanning. The method consists in tumor treatment by a light beam of a small cross section which incrementally moves through the chosen area with a defined delay at each point and repetitively re-scans a zone starting from the initial position. Experimental evaluation of the method in vitro on murine tumor model showed that despite the dose, applied by scanning irradiation mode, was 400 times lower, the tumor inhibition rate conceded to attained with continuous irradiation mode by only 20%.

  15. Two-Photon Laser Scanning Microscopy

    NASA Astrophysics Data System (ADS)

    Nimmerjahn, A.; Theer, P.; Helmchen, F.

    Since its inception more than 15 years ago, two-photon laser scanning microscopy (2PLSM) has found widespread use in biological and medical research. Two-photon microscopy is based on simultaneous absorption of two photons by fluorophores and subsequent fluorescence emission, a process which under normal illumination conditions is highly improbable. Theoretically described around 1930 by Maria Göppert-Mayer [1], the first experimental demonstration of two-photon excitation had to await the invention of the laser, which produced sufficiently high light intensities to observe two-photon absorption events [2]. Only after the development of ultrafast lasers providing subpicosecond light pulses with high peak power intensities, however, two-photon-excited fluorescence became practical in a laser-scanning microscope [3]. Since then 2PLSM has developed into the method of choice for high-resolution imaging in living animals (reviewed in [4,5]). One of the main reasons is the low sensitivity of 2PLSM to light scattering, which enables imaging relatively deep inside biological tissue and direct observation of the dynamic behavior of cells in their native environment. In this chapter, we introduce the physical principles governing 2PLSM and briefly describe the key instrument components. We give an overview of fluorescence labeling techniques and how they are combined with 2PLSM for functional imaging and photomanipulation in living tissue. Finally, we discuss limitations and provide some future perspectives.

  16. Mobile Laser Scanning for Indoor Modelling

    NASA Astrophysics Data System (ADS)

    Thomson, C.; Apostolopoulos, G.; Backes, D.; Boehm, J.

    2013-10-01

    The process of capturing and modelling buildings has gained increased focus in recent years with the rise of Building Information Modelling (BIM). At the heart of BIM is a process change for the construction and facilities management industries whereby a BIM aids more collaborative working through better information exchange, and as a part of the process Geomatic/Land Surveyors are not immune from the changes. Terrestrial laser scanning has been proscribed as the preferred method for rapidly capturing buildings for BIM geometry. This is a process change from a traditional measured building survey just with a total station and is aided by the increasing acceptance of point cloud data being integrated with parametric building models in BIM tools such as Autodesk Revit or Bentley Architecture. Pilot projects carried out previously by the authors to investigate the geometry capture and modelling of BIM confirmed the view of others that the process of data capture with static laser scan setups is slow and very involved requiring at least two people for efficiency. Indoor Mobile Mapping Systems (IMMS) present a possible solution to these issues especially in time saved. Therefore this paper investigates their application as a capture device for BIM geometry creation over traditional static methods through a fit-for-purpose test.

  17. Extraction of power lines from mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Xiang, Qing; Li, Jonathan; Wen, Chenglu; Huang, Pengdi

    2016-03-01

    Modern urban life is becoming increasingly more dependent on reliable electric power supply. Since power outages cause substantial financial losses to producers, distributors and consumers of electric power, it is in the common interest to minimize failures of power lines. In order to detect defects as early as possible and to plan efficiently the maintenance activities, distribution networks are regularly inspected. Carrying out foot patrols or climbing the structures to visually inspect transmission lines and aerial surveys (e.g., digital imaging or most recent airborne laser scanning (ALS) are the two most commonly used methods of power line inspection. Although much faster in comparison to the foot patrol inspection, aerial inspection is more expensive and usually less accurate, in complex urban areas particularly. This paper presents a scientific work that is done in the use of mobile laser scanning (MLS) point clouds for automated extraction of power lines. In the proposed method, 2D power lines are extracted using Hough transform in the projected XOY plane and the 3D power line points are visualized after the point searching. Filtering based on an elevation threshold is applied, which is combined with the vehicle's trajectory in the horizontal section.

  18. Three-Dimensional Laser Scanning for Geometry Documentation and Construction Management of Highway Tunnels during Excavation

    PubMed Central

    Gikas, Vassilis

    2012-01-01

    Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered. PMID:23112655

  19. Three-dimensional laser scanning for geometry documentation and construction management of highway tunnels during excavation.

    PubMed

    Gikas, Vassilis

    2012-01-01

    Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered. PMID:23112655

  20. Automatic Railway Power Line Extraction Using Mobile Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Zhang, Shanxin; Wang, Cheng; Yang, Zhuang; Chen, Yiping; Li, Jonathan

    2016-06-01

    Research on power line extraction technology using mobile laser point clouds has important practical significance on railway power lines patrol work. In this paper, we presents a new method for automatic extracting railway power line from MLS (Mobile Laser Scanning) data. Firstly, according to the spatial structure characteristics of power-line and trajectory, the significant data is segmented piecewise. Then, use the self-adaptive space region growing method to extract power lines parallel with rails. Finally use PCA (Principal Components Analysis) combine with information entropy theory method to judge a section of the power line whether is junction or not and which type of junction it belongs to. The least squares fitting algorithm is introduced to model the power line. An evaluation of the proposed method over a complicated railway point clouds acquired by a RIEGL VMX450 MLS system shows that the proposed method is promising.

  1. Confocal laser scanning microscopy of apoptosis in organogenesis-stage mouse embryos

    EPA Science Inventory

    Confocal laser scanning microscopy combined with a vital stain has been used to study apoptosis in organogenesis-stage mouse embryos. In order to achieve optical sectioning through embryos, it was necessary to use low power objectives and to prepare the sample appropriately. Mous...

  2. TelePresence Confocal Laser Scanning Microscopy.

    PubMed

    Youngblom, Janey H.; Youngblom, James J.; Wilkinson, Jerry

    2001-05-01

    The advent of the Internet has allowed the development of remote access capabilities to a growing variety and number of microscopy systems. To date, the confocal microscope has not been included among these systems. At the California State University (CSU) Confocal Microscopy Core Facility, we have established a remote access confocal laser scanning microscope facility that allows users with virtually any type of computer platform to connect to our system. Our Leica TCS NT confocal system is accessible to any authorized user via the Internet by using a free software program called VNC (Virtual Network Computing). Once connectivity is established, remote users are able to control virtually all the functions to conduct real-time image analysis and quantitative assessments of their specimen. They can also move the motorized stage to view different regions of their specimen by using a software program associated with the stage. At the end of the session, all files generated during the session can be downloaded to the user's computer from a link on the CSU confocal website. A number of safeguard features have been developed to ensure security and privacy of data acquired during a remote session. PMID:12597815

  3. Automatic change detection using mobile laser scanning

    NASA Astrophysics Data System (ADS)

    Hebel, M.; Hammer, M.; Gordon, M.; Arens, M.

    2014-10-01

    Automatic change detection in 3D environments requires the comparison of multi-temporal data. By comparing current data with past data of the same area, changes can be automatically detected and identified. Volumetric changes in the scene hint at suspicious activities like the movement of military vehicles, the application of camouflage nets, or the placement of IEDs, etc. In contrast to broad research activities in remote sensing with optical cameras, this paper addresses the topic using 3D data acquired by mobile laser scanning (MLS). We present a framework for immediate comparison of current MLS data to given 3D reference data. Our method extends the concept of occupancy grids known from robot mapping, which incorporates the sensor positions in the processing of the 3D point clouds. This allows extracting the information that is included in the data acquisition geometry. For each single range measurement, it becomes apparent that an object reflects laser pulses in the measured range distance, i.e., space is occupied at that 3D position. In addition, it is obvious that space is empty along the line of sight between sensor and the reflecting object. Everywhere else, the occupancy of space remains unknown. This approach handles occlusions and changes implicitly, such that the latter are identifiable by conflicts of empty space and occupied space. The presented concept of change detection has been successfully validated in experiments with recorded MLS data streams. Results are shown for test sites at which MLS data were acquired at different time intervals.

  4. Quality Analysis and Correction of Mobile Backpack Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Rönnholm, P.; Liang, X.; Kukko, A.; Jaakkola, A.; Hyyppä, J.

    2016-06-01

    Backpack laser scanning systems have emerged recently enabling fast data collection and flexibility to make measurements also in areas that cannot be reached with, for example, vehicle-based laser scanners. Backpack laser scanning systems have been developed both for indoor and outdoor use. We have developed a quality analysis process in which the quality of backpack laser scanning data is evaluated in the forest environment. The reference data was collected with an unmanned aerial vehicle (UAV) laser scanning system. The workflow included noise filtering, division of data into smaller patches, ground point extraction, ground data decimation, and ICP registration. As a result, we managed to observe the misalignments of backpack laser scanning data for 97 patches each including data from circa 10 seconds period of time. This evaluation revealed initial average misalignments of 0.227 m, 0.073 and -0.083 in the easting, northing and elevation directions, respectively. Furthermore, backpack data was corrected according to the ICP registration results. Our correction algorithm utilized the time-based linear transformation of backpack laser scanning point clouds. After the correction of data, the ICP registration was run again. This revealed remaining misalignments between the corrected backpack laser scanning data and the original UAV data. We found average misalignments of 0.084, 0.020 and -0.005 meters in the easting, northing and elevation directions, respectively.

  5. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle...

  6. Laser Scanning and Simulation at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Kickbusch, Tracey E.

    2012-01-01

    We perform simulations of ground operations leading up launch at Kennedy Space Center and Vandenberg Air Force Base in CA. We use Laser Scanning, Modeling and Simulations to make sure operations are feasible, efficient, and safe.

  7. Reservoir shore development in long range terrestrial laser scanning monitoring.

    NASA Astrophysics Data System (ADS)

    Kaczmarek, Halina

    2016-04-01

    Shore zones of reservoirs are in most cases very active, getting transformed as a result of coastal processes and mass movements initiated on the slopes surrounding the reservoir. From the point of view of the users of water reservoirs shore recession strongly undesirable as it causes destruction to infrastructure and buildings located in the immediate vicinity of the reservoir. For this reason, reservoir shores require continuous geodetic monitoring. Fast and accurate geodetic measurements covering shore sections several kilometers long, often in poorly accessible areas, are available using long range terrestrial laser scanning (TLS). The possibilities of using long range terrestrial laser scanning are shown on the example of the reservoir Jeziorsko on the Warta River (Central Poland). This reservoir, created in the years 1986-1992, is a typical retention reservoir, the annual fluctuations of which reach 5 m. Depending on the water level its surface area ranges from 42.3 to 19.6 km2. The width of the reservoir is 2.5 km. The total shore length of the reservoir, developed in Quaternary till and sand-till sediments, is 44.3 km, including 30.1 km of the unreinforced shore. Out of the unreinforced shore 27% is subject to coastal erosion. The cliff heights vary from a few cm to 12.5 meters, and the current rate of the cliff recession ranges from 0 to 1.12 m/y. The study used a terrestrial long range laser scanner Riegl VZ-4000 of a range of up to 4000 m. It enabled conducting the measurements of the cliff recession from the opposite shore of the reservoir, with an angular resolution of 0.002°, which gives about 50 measurement points per 1 m2. The measurements were carried out in the years 2014-2015, twice a year, in early spring before high water level, and in late autumn at a dropping water level. This allowed the separation of the impact of coastal processes and frost weathering on the cliff recession and their quantitative determination. The size and nature of

  8. Automatic Classification of Trees from Laser Scanning Point Clouds

    NASA Astrophysics Data System (ADS)

    Sirmacek, B.; Lindenbergh, R.

    2015-08-01

    Development of laser scanning technologies has promoted tree monitoring studies to a new level, as the laser scanning point clouds enable accurate 3D measurements in a fast and environmental friendly manner. In this paper, we introduce a probability matrix computation based algorithm for automatically classifying laser scanning point clouds into 'tree' and 'non-tree' classes. Our method uses the 3D coordinates of the laser scanning points as input and generates a new point cloud which holds a label for each point indicating if it belongs to the 'tree' or 'non-tree' class. To do so, a grid surface is assigned to the lowest height level of the point cloud. The grids are filled with probability values which are calculated by checking the point density above the grid. Since the tree trunk locations appear with very high values in the probability matrix, selecting the local maxima of the grid surface help to detect the tree trunks. Further points are assigned to tree trunks if they appear in the close proximity of trunks. Since heavy mathematical computations (such as point cloud organization, detailed shape 3D detection methods, graph network generation) are not required, the proposed algorithm works very fast compared to the existing methods. The tree classification results are found reliable even on point clouds of cities containing many different objects. As the most significant weakness, false detection of light poles, traffic signs and other objects close to trees cannot be prevented. Nevertheless, the experimental results on mobile and airborne laser scanning point clouds indicate the possible usage of the algorithm as an important step for tree growth observation, tree counting and similar applications. While the laser scanning point cloud is giving opportunity to classify even very small trees, accuracy of the results is reduced in the low point density areas further away than the scanning location. These advantages and disadvantages of two laser scanning point

  9. Stereo vision based hand-held laser scanning system design

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Wang, Jinming

    2011-11-01

    Although 3D scanning system is used more and more broadly in many fields, such computer animate, computer aided design, digital museums, and so on, a convenient scanning device is expansive for most people to afford. In another hand, imaging devices are becoming cheaper, a stereo vision system with two video cameras cost little. In this paper, a hand held laser scanning system is design based on stereo vision principle. The two video cameras are fixed tighter, and are all calibrated in advance. The scanned object attached with some coded markers is in front of the stereo system, and can be changed its position and direction freely upon the need of scanning. When scanning, the operator swept a line laser source, and projected it on the object. At the same time, the stereo vision system captured the projected lines, and reconstructed their 3D shapes. The code markers are used to translate the coordinate system between scanned points under different view. Two methods are used to get more accurate results. One is to use NURBS curves to interpolate the sections of the laser lines to obtain accurate central points, and a thin plate spline is used to approximate the central points, and so, an exact laser central line is got, which guards an accurate correspondence between tow cameras. Another way is to incorporate the constraint of laser swept plane on the reconstructed 3D curves by a PCA (Principle Component Analysis) algorithm, and more accurate results are obtained. Some examples are given to verify the system.

  10. Managing multiple image stacks from confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Zerbe, Joerg; Goetze, Christian H.; Zuschratter, Werner

    1999-05-01

    A major goal in neuroanatomy is to obtain precise information about the functional organization of neuronal assemblies and their interconnections. Therefore, the analysis of histological sections frequently requires high resolution images in combination with an overview about the structure. To overcome this conflict we have previously introduced a software for the automatic acquisition of multiple image stacks (3D-MISA) in confocal laser scanning microscopy. Here, we describe a Windows NT based software for fast and easy navigation through the multiple images stacks (MIS-browser), the visualization of individual channels and layers and the selection of user defined subregions. In addition, the MIS browser provides useful tools for the visualization and evaluation of the datavolume, as for instance brightness and contrast corrections of individual layers and channels. Moreover, it includes a maximum intensity projection, panning and zoom in/out functions within selected channels or focal planes (x/y) and tracking along the z-axis. The import module accepts any tiff-format and reconstructs the original image arrangement after the user has defined the sequence of images in x/y and z and the number of channels. The implemented export module allows storage of user defined subregions (new single image stacks) for further 3D-reconstruction and evaluation.

  11. Efficient terrestrial laser scan segmentation exploiting data structure

    NASA Astrophysics Data System (ADS)

    Mahmoudabadi, Hamid; Olsen, Michael J.; Todorovic, Sinisa

    2016-09-01

    New technologies such as lidar enable the rapid collection of massive datasets to model a 3D scene as a point cloud. However, while hardware technology continues to advance, processing 3D point clouds into informative models remains complex and time consuming. A common approach to increase processing efficiently is to segment the point cloud into smaller sections. This paper proposes a novel approach for point cloud segmentation using computer vision algorithms to analyze panoramic representations of individual laser scans. These panoramas can be quickly created using an inherent neighborhood structure that is established during the scanning process, which scans at fixed angular increments in a cylindrical or spherical coordinate system. In the proposed approach, a selected image segmentation algorithm is applied on several input layers exploiting this angular structure including laser intensity, range, normal vectors, and color information. These segments are then mapped back to the 3D point cloud so that modeling can be completed more efficiently. This approach does not depend on pre-defined mathematical models and consequently setting parameters for them. Unlike common geometrical point cloud segmentation methods, the proposed method employs the colorimetric and intensity data as another source of information. The proposed algorithm is demonstrated on several datasets encompassing variety of scenes and objects. Results show a very high perceptual (visual) level of segmentation and thereby the feasibility of the proposed algorithm. The proposed method is also more efficient compared to Random Sample Consensus (RANSAC), which is a common approach for point cloud segmentation.

  12. Confocal laser scanning microscopy in study of bone calcification

    NASA Astrophysics Data System (ADS)

    Nishikawa, Tetsunari; Kokubu, Mayu; Kato, Hirohito; Imai, Koichi; Tanaka, Akio

    2012-12-01

    Bone regeneration in mandible and maxillae after extraction of teeth or tumor resection and the use of rough surface implants in bone induction must be investigated to elucidate the mechanism of calcification. The calcified tissues are subjected to chemical decalcification or physical grinding to observe their microscopic features with light microscopy and transmission electron microscopy where the microscopic tissue morphology is significantly altered. We investigated the usefulness of confocal laser scanning microscopy (CLSM) for this purpose. After staggering the time of administration of calcein and alizarin red to experimental rats and dogs, rat alveolar bone and dog femur grafted with coral as scaffold or dental implants were observed with CLSM. In rat alveolar bone, the calcification of newly-formed bone and net-like canaliculi was observed at the mesial bone from the roots progressed at the rate of 15 μm/day. In dog femur grafted with coral, newly-formed bones along the space of coral were observed in an orderly manner. In dog femur with dental implants, after 8 weeks, newly-formed bone proceeded along the rough surface of the implants. CLSM produced high-magnification images of newly-formed bone and thin sections were not needed.

  13. Laser Scanning Cytometry: Principles and Applications—An Update

    PubMed Central

    Pozarowski, Piotr; Holden, Elena; Darzynkiewicz, Zbigniew

    2012-01-01

    Laser scanning cytometer (LSC) is the microscope-based cytofluorometer that offers a plethora of unique analytical capabilities, not provided by flow cytometry (FCM). This review describes attributes of LSC and covers its numerous applications derived from plentitude of the parameters that can be measured. Among many LSC applications the following are emphasized: (a) assessment of chromatin condensation to identify mitotic, apoptotic cells, or senescent cells; (b) detection of nuclear or mitochondrial translocation of critical factors such as NF-κB, p53, or Bax; (c) semi-automatic scoring of micronuclei in mutagenicity assays; (d) analysis of fluorescence in situ hybridization (FISH) and use of the FISH analysis attribute to measure other punctuate fluorescence patterns such as γH2AX foci or receptor clustering; (e) enumeration and morphometry of nucleoli and other cell organelles; (f) analysis of progeny of individual cells in clonogenicity assay; (g) cell immunophenotyping; (h) imaging, visual examination, or sequential analysis using different probes of the same cells upon their relocation; (i) in situ enzyme kinetics, drug uptake, and other time-resolved processes; (j) analysis of tissue section architecture using fluorescent and chromogenic probes; (k) application for hypocellular samples (needle aspirate, spinal fluid, etc.); and (l) other clinical applications. Advantages and limitations of LSC are discussed and compared with FCM. PMID:23027005

  14. Plastic casts and confocal laser scanning microscopy applied to the observation of enamel tubules in the red Kangaroo (Macropus rufus).

    PubMed

    Suzuki, Masatsugu; Ushijima, Natsumi; Kohno, Ayako; Sawa, Yoshihiko; Yoshida, Shigemitsu; Sekikawa, Mitsuo; Ohtaishi, Noriyuki

    2003-03-01

    Scanning electron microscopy for plastic casts and confocal laser scanning microscopy for Villanueva bone-stained ground sections were used together to observe enamel tubules in red kangaroo molars. Although the tubular structures such as terminals, bends, expansions, splits, divergences and rejoinings in this species were within the variations of marsupial species, their morphological characteristics were demonstrated with extremely clear and persuasive images. Thus, the combined observations of plastic casts by scanning electron microscopy and Villanueva bone-stain sections by confocal laser scanning microscopy were found to be of value for the investigation of enamel tubules and tubular structures in other hard tissues.

  15. Microscopic tomography by laser scanning microscopy and its three-dimensional reconstruction.

    PubMed

    Takamatsu, T; Fujita, S

    1988-03-01

    We have developed a new confocal laser scanning microscope equipped with two galvanometer mirrors which swing the laser beam. With this set up we can observe large and fragile specimens. Using a focused laser beam as light source to minimize 'flare' and a pinhole in front of a photodetector to eliminate out-of-focus data, we could obtain a depth-discriminated fluorescence image. The scanning apparatus of our system can eliminate mechanical vibration and sweep widely, to obtain images at a low magnification. A thinly sectioned image with high resolution and high contrast could be obtained optically from an in situ thick specimen. We have called this technique 'microscopic tomography'. Combining the laser scanning microscope with the colour image analyser generated semi-automatically a three-dimensional picture of the biological material with information on its interior. PMID:3398041

  16. Application of in vivo laser scanning microscope in dermatology

    NASA Astrophysics Data System (ADS)

    Lademann, Juergen; Richter, H.; Otberg, N.; Lawrenz, F.; Blume-Peytavi, U.; Sterry, W.

    2003-10-01

    The state of the art of in-vivo and in-vitro penetration measurements of topically applied substances is described. Only optical techniques represent online measuring methods based on the absorption or scattering properties of the topically applied substances. Laser scanning microscopy (LSM) has become a promising method for investigations in dermatology and skin physiology, after it was possible to analyze the skin surface on any body side in-vivo. In the present paper the application of a dermatological laser scanning microscope for penetration and distribution measurements of topically applied substances is described. The intercellular and follicular penetration pathways were studied.

  17. Laser scanning cytometry as a tool for biomarker validation

    NASA Astrophysics Data System (ADS)

    Mittag, Anja; Füldner, Christiane; Lehmann, Jörg; Tarnok, Attila

    2013-03-01

    Biomarkers are essential for diagnosis, prognosis, and therapy. As diverse is the range of diseases the broad is the range of biomarkers and the material used for analysis. Whereas body fluids can be relatively easily obtained and analyzed, the investigation of tissue is in most cases more complicated. The same applies for the screening and the evaluation of new biomarkers and the estimation of the binding of biomarkers found in animal models which need to be transferred into applications in humans. The latter in particular is difficult if it recognizes proteins or cells in tissue. A better way to find suitable cellular biomarkers for immunoscintigraphy or PET analyses may be therefore the in situ analysis of the cells in the respective tissue. In this study we present a method for biomarker validation using Laser Scanning Cytometry which allows the emulation of future in vivo analysis. The biomarker validation is exemplarily shown for rheumatoid arthritis (RA) on synovial membrane. Cryosections were scanned and analyzed by phantom contouring. Adequate statistical methods allowed the identification of suitable markers and combinations. The fluorescence analysis of the phantoms allowed the discrimination between synovial membrane of RA patients and non-RA control sections by using median fluorescence intensity and the "affected area". As intensity and area are relevant parameters of in vivo imaging (e.g. PET scan) too, the presented method allows emulation of a probable outcome of in vivo imaging, i.e. the binding of the target protein and hence, the validation of the potential of the respective biomarker.

  18. CONFOCAL LASER SCANNING MICROSCOPY OF RAT FOLLICLE DEVELOPMENT

    EPA Science Inventory

    This study used confocal laser scanning microscopy (CLSM) to study follicular development in millimeter pieces of rat ovary. To use this technology, it is essential to stain the tissue before laser excitation with the confocal microscope. Various fluorescent stains (Yo-Pro, Bo-Pr...

  19. FOOD SURFACE TEXTURE MEASUREMENT USING REFLECTIVE CONFOCAL LASER SCANNING MICROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confocal laser scanning microscopy (CLSM) was used in the reflection mode to characterize the surface texture (roughness) of sliced food surfaces. Sandpapers of grit size between 150 and 600 were used as the height reference to standardize the CLSM hardware settings. Sandpaper particle sizes were v...

  20. Intersecting kink bands quantified by laser scanning and differential geometry

    NASA Astrophysics Data System (ADS)

    Dunham, R. E.; Crider, J. G.

    2010-12-01

    Microtopography derived from laser scanning is expressed by DEMs that can be analyzed using differential geometry. We apply this technique to rock hand samples containing intersecting kink bands in order to quantitatively describe the shape of a folded surface and understand the localization of strain in deformed rocks. This study is the first to apply laser scanning and geometric curvature analysis to intersecting kink bands in order to better describe the variation of kink band geometries and intersections in plan view and to evaluate relationships between different kink band parameters. A complex set of monoclinal contractional kink bands is well exposed in outcrops of the Darrington Phyllite on Samish Island, northwestern Washington, which provide a three-dimensional view of kink band geometries. Kink bands in cross section have straight, parallel boundaries that deform a well-defined foliation; in plan view, however, kink band hinges curve and anastomose across the foliation surface, and adjacent bands commonly intersect. Three types of intersections are common: crossing (X), bifurcating (Y), and obliquely truncating (λ); many kink bands also taper out along strike. Geometric curvature analyses were performed on millimeter-resolution DEMs of hand samples containing intersecting kink bands. Maps of different curvature parameters (e.g. mean curvature, geologic curvature) clearly outline kink bands in the samples and illuminate the behavior of kink band hinges in each type of intersection. In X-type intersections, curvature increases where two hinges of similar kink sense cross (i.e. anticlinal/anticlinal hinges), increasing strain; where two hinges of opposing sense cross (anticlinal/synclinal), curvature decreases and the surface is effectively unfolded. In Y-type intersections, a single parent band widens and splits into two equally narrow daughter bands, and new inner hinges are nucleated below the bifurcation point. The two daughter bands accommodate

  1. Line based reconstruction from terrestrial laser scanning data

    NASA Astrophysics Data System (ADS)

    Briese, Christian; Pfeifer, Norbert

    2008-08-01

    The methods for reconstructing objects from dense point clouds, typically acquired by terrestrial laser scanning (TLS), are currently unsatisfying, especially from a geodetic perspective, for a number of reasons. Digitization in the point cloud lacks redundancy and no stochastic measures are provided generally. Reconstruction from primitives, e.g., planes, spheres, and cylinders, enforces strong requirements on (large) object parts, which are strictly valid only for very special cases. In this article we propose a new reconstruction technique for terrestrial laser scanning point clouds addressing those issues. In line with photogrammetric restitution, lines, not necessarily straight, are reconstructed in a process providing precision, i.e. internal quality measures. Methods for reconstructing different types of lines will be presented, in particular break lines, form lines, step edges, and boundary lines. The process features a high degree of automation, reducing the manual interaction to supplying one approximate point or one short segment per relevant line. The method will be presented with two examples.

  2. Optimal lens design and use in laser-scanning microscopy

    PubMed Central

    Negrean, Adrian; Mansvelder, Huibert D.

    2014-01-01

    In laser-scanning microscopy often an off-the-shelf achromatic doublet is used as a scan lens which can reduce the available diffraction-limited field-of-view (FOV) by a factor of 3 and introduce chromatic aberrations that are scan angle dependent. Here we present several simple lens designs of superior quality that fully make use of high-NA low-magnification objectives, offering diffraction-limited imaging over a large FOV and wavelength range. We constructed a two-photon laser-scanning microscope with optimized custom lenses which had a near diffraction limit point-spread-function (PSF) with less than 3.6% variation over a 400 µm FOV and less than 0.5 µm lateral color between 750 and 1050 nm. PMID:24877017

  3. Airborne laser scanning for high-resolution mapping of Antarctica

    NASA Astrophysics Data System (ADS)

    Csatho, Bea; Schenk, Toni; Krabill, William; Wilson, Terry; Lyons, William; McKenzie, Garry; Hallam, Cheryl; Manizade, Serdar; Paulsen, Timothy

    In order to evaluate the potential of airborne laser scanning for topographic mapping in Antarctica and to establish calibration/validation sites for NASA's Ice, Cloud and land Elevation Satellite (ICESat) altimeter mission, NASA, the U.S. National Science Foundation (NSF), and the U.S. Geological Survey (USGS) joined forces to collect high-resolution airborne laser scanning data.In a two-week campaign during the 2001-2002 austral summer, NASA's Airborne Topographic Mapper (ATM) system was used to collect data over several sites in the McMurdo Sound area of Antarctica (Figure 1a). From the recorded signals, NASA computed laser points and The Ohio State University (OSU) completed the elaborate computation/verification of high-resolution Digital Elevation Models (DEMs) in 2003. This article reports about the DEM generation and some exemplary results from scientists using the geomorphologic information from the DEMs during the 2003-2004 field season.

  4. Software for visualization, analysis, and manipulation of laser scan images

    NASA Astrophysics Data System (ADS)

    Burnsides, Dennis B.

    1997-03-01

    The recent introduction of laser surface scanning to scientific applications presents a challenge to computer scientists and engineers. Full utilization of this two- dimensional (2-D) and three-dimensional (3-D) data requires advances in techniques and methods for data processing and visualization. This paper explores the development of software to support the visualization, analysis and manipulation of laser scan images. Specific examples presented are from on-going efforts at the Air Force Computerized Anthropometric Research and Design (CARD) Laboratory.

  5. Clinical applications of in vivo fluorescence confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Oh, Chilhwan; Park, Sangyong; Kim, Junhyung; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Chun, Byungseon; Gweon, Daegab

    2008-02-01

    Living skin for basic and clinical research can be evaluated by Confocal Laser Scanning Microscope (CLSM) non-invasively. CLSM imaging system can achieve skin image its native state either "in vivo" or "fresh biopsy (ex vivo)" without fixation, sectioning and staining that is necessary for routine histology. This study examines the potential fluorescent CLSM with a various exogenous fluorescent contrast agent, to provide with more resolution images in skin. In addition, in vivo fluorescent CLSM researchers will be extended a range of potential clinical application. The prototype of our CLSM system has been developed by Prof. Gweon's group. The operating parameters are composed of some units, such as illuminated wavelength 488 nm, argon illumination power up to 20mW on the skin, objective lens, 0.9NA oil immersion, axial resolution 1.0μm, field of view 200μm x 100μm (lateral resolution , 0.3μm). In human volunteer, fluorescein sodium was administrated topically and intradermally. Animal studies were done in GFP transgenic mouse, IRC mouse and pig skin. For imaging of animal skin, fluorescein sodium, acridine orange, and curcumine were used for fluorescein contrast agent. We also used the GFP transgenic mouse for fluorescein CLSM imaging. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. Acridin Orange can be highlight nuclei in viable keratinocyte. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, hair and eccrine gland. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. In

  6. Characterization of multiphoton laser scanning device optical parameters for image restoration

    NASA Astrophysics Data System (ADS)

    Fischer, Frank; Konig, Karsten; Puschmann, Stefan; Wepf, Roger; Riemann, Iris; Ulrich, Volker; Fischer, Peter

    2004-09-01

    Fluorescent nanobeads embedded in agarose and skin biopsies were used to optically characterize spatial and temporal resolution of multiphoton laser scanning devices (MPLSD). Optical sections based on two-photon excited bead fluorescence have been performed at various sample depths. Three-dimensional reconstruction of the image stacks allowed determination of the point spread function. Using calculated point spread functions to apply deconvolution procedures (e.g. Huygens software), the visualization and hence the interpretation of intradermal structures, such as extracellular matrix components in 150 μm tissue depth, was improved.

  7. Transmissive liquid-crystal device correcting primary coma aberration and astigmatism in laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Tanabe, Ayano; Hibi, Terumasa; Ipponjima, Sari; Matsumoto, Kenji; Yokoyama, Masafumi; Kurihara, Makoto; Hashimoto, Nobuyuki; Nemoto, Tomomi

    2016-03-01

    Laser scanning microscopy allows 3D cross-sectional imaging inside biospecimens. However, certain aberrations produced can degrade the quality of the resulting images. We previously reported a transmissive liquid-crystal device that could compensate for the predominant spherical aberrations during the observations, particularly in deep regions of the samples. The device, inserted between the objective lens and the microscope revolver, improved the image quality of fixed-mouse-brain slices that were observed using two-photon excitation laser scanning microscopy, which was originally degraded by spherical aberration. In this study, we developed a transmissive device that corrects primary coma aberration and astigmatism, motivated by the fact that these asymmetric aberrations can also often considerably deteriorate image quality, even near the sample surface. The device's performance was evaluated by observing fluorescent beads using single-photon excitation laser scanning microscopy. The fluorescence intensity in the image of the bead under a cover slip tilted in the y-direction was increased by 1.5 times after correction by the device. Furthermore, the y- and z-widths of the imaged bead were reduced to 66% and 65%, respectively. On the other hand, for the imaged bead sucked into a glass capillary in the longitudinal x-direction, correction with the device increased the fluorescence intensity by 2.2 times compared to that of the aberrated image. In addition, the x-, y-, and z-widths of the bead image were reduced to 75%, 53%, and 40%, respectively. Our device successfully corrected several asymmetric aberrations to improve the fluorescent signal and spatial resolution, and might be useful for observing various biospecimens.

  8. Nonlinear Laser Scanning Microscopy of Human Vocal Folds

    PubMed Central

    Miri, Amir K.; Tripathy, Umakanta; Mongeau, Luc; Wiseman, Paul W.

    2012-01-01

    Objectives/Hypothesis The purpose of this work is to apply nonlinear laser scanning microscopy (NLSM) for visualizing the morphology of extracellular matrix proteins within human vocal folds. This technique may potentially assist clinicians in making rapid diagnoses of vocal fold tissue disease or damage. Microstructural characterization, based on NLSM, provides valuable information for better understanding the molecular mechanisms and tissue structure. Study Design Experimental. Ex-vivo human vocal fold Methods A custom built multi-modal nonlinear laser scanning microscope was utilized to scan fibrillar proteins in three 4% formaldehyde-fixed cadaveric samples. Collagen and elastin, key extracellular matrix proteins in the vocal fold lamina propria, were imaged by two nonlinear microscopy modalities: second harmonic generation (SHG) and two-photon fluorescence (TPF), respectively. An experimental protocol was introduced to characterize the geometrical properties of the imaged fibrous proteins. Results The NLSM revealed the biomorphology of the human vocal fold fibrous proteins. No photobleaching was observed for the incident laser power of ~60 mW before the excitation objective. Types I and III fibrillar collagen were imaged without label in the tissue by intrinsic SHG. Imaging while rotating the incident laser light-polarization direction confirmed a helical shape for the collagen fibers. The amplitude, periodicity and overall orientation were then computed for the helically-distributed collagen network. The elastin network was simultaneously imaged via TPF and found to have a basket-like structure. In some regions, particularly close to the epithelium, co-localization of both extracellular matrix components were observed. Conclusions A benchmark study is presented for quantitative real-time ex-vivo nonlinear laser scanning microscopy imaging of the extracellular macromolecules in human vocal fold lamina propria. The results are promising for clinical

  9. Laser-scanning Doppler photoacoustic microscopy based on temporal correlation

    PubMed Central

    Song, Wei; Liu, Wenzhong; Zhang, Hao F.

    2013-01-01

    We present a methodology to measure absolute flow velocity using laser-scanning photoacoustic microscopy. To obtain the Doppler angle, the angle between ultrasonic detection axis and flow direction, we extracted the distances between the transducer and three adjacent scanning points along the flow and repeatedly applied the law of cosines. To measure flow velocity along the ultrasonic detection axis, we calculated the time shift between two consecutive photoacoustic waves at the same scanning point, then converted the time shift to velocity according to the sound velocity and time interval between two laser illuminations. We verified our method by imaging flow phantoms. PMID:23825803

  10. Registration Procedures for Terrestrial Laser Scanning in Geomorphologic Studies

    NASA Astrophysics Data System (ADS)

    Collins, B. D.; Kayen, R.; Minasian, D.

    2006-12-01

    Terrestrial based laser scanning, from either vehicle or tripod mounts allows the collection of geomorphologic data at previously unprecedented detail and volume. However, despite the ease of collecting this data in many settings, post-processing datasets collected without laser-visible reflectors within individual scans can lead to difficulties in both registration and georeferencing procedures. We have been actively involved in gathering data sets from a number of different environments and have been developing various techniques to post-process the data using surface registration methods. These methods use the point cloud or model surface to find a best-fit of the three-dimensional terrain. Recently, we have collected laser scan data of levee breaches in New Orleans following Hurricane Katrina, a glacial cirque basin in the Canadian Rockies, a deep-seated landslide mass in Ventura County, California, rapidly evolving coastal bluffs in Central California, and sand bars and archeological sites in Grand Canyon National Park, Arizona. In each of these projects, setting up accurately surveyed reflectors was impractical due to the locations dynamic and fairly inaccessible setting. Robust surface registration procedures were therefore needed to provide accurate terrain models. We have used laser scanning results from these projects to assess the efficiency of the various post- processing methodologies for obtaining final registered and georeferenced point clouds and surface models. We compared registration results obtained both with and without accurate GPS coordinates for the laser scanner origin (Ventura and coastal landslides), use of a supporting total station unit (Grand Canyon), and collection of DGPS data on targets imaged in the LIDAR data after the scanning process (Katrina Levees). In many of these settings, the model fit improved by four times, from a root mean square error of 20 cm to 5cm when accurately surveyed coordinates were utilized for the laser scan

  11. Visualization package for 3D laser-scanned geometry

    NASA Astrophysics Data System (ADS)

    Neumann, Paul F.; Sadler, Lewis L.

    1993-06-01

    A computer software package named LEGO was designed and implemented to enable medical personnel to explore and manipulate laser scanned 3D geometry obtained from a Cyberware 4020PS scanner. This type of scanner reconstructs a real world object into a mathematical computer model by collecting thousands of depth measurement using a low powered laser. LEGO consists of a collection of tools that can be interactively combined to accomplish complex tasks. Tools fall into five major categories: viewing, simple, quantitative, manipulative, and miscellaneous. This paper is based on a masters thesis obtained from the University of Illinois at Chicago.

  12. Laser-scanning optical-resolution photoacoustic microscopy.

    PubMed

    Xie, Zhixing; Jiao, Shuliang; Zhang, Hao F; Puliafito, Carmen A

    2009-06-15

    We have developed a laser-scanning optical-resolution photoacoustic microscopy method that can potentially fuse with existing optical microscopic imaging modalities. To acquire an image, the ultrasonic transducer is kept stationary during data acquisition, and only the laser light is raster scanned by an x-y galvanometer scanner. A lateral resolution of 7.8 microm and a circular field of view with a diameter of 6 mm were achieved in an optically clear medium. Using a laser system working at a pulse repetition rate of 1,024 Hz, the data acquisition time for an image consisting of 256 x 256 pixels was less than 2 min. PMID:19529698

  13. Monitoring stream bluff erosion using repeat terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Neitzel, G.; Gran, K. B.

    2012-12-01

    Terrestrial laser scanning (TLS) technology provides high-resolution topographic data that can be used to detect geomorphic change in fluvial environments. In this study, we utilize successive terrestrial laser scans to investigate the relationship between peak flow rates and stream bluff erosion in the Amity Creek watershed in Duluth, Minnesota. We also combine TLS scan results with bluff inventories from airborne lidar to estimate the volume of sediment erosion from bluffs in the watershed, which is an important source of fine sediment contributing to the creek's turbidity impairment. We selected nine study bluffs to conduct terrestrial laser scans on after all significant flood events over a two-year time period. The study employs a Faro Focus 3D phase-shift laser to collect data. Post-processing of the TLS-point cloud data sets involves: (1) removal of vegetation and objects other than the erosional surface of interest; (2) decimation of the point cloud in PC Tools and extraction of zmin values to produce a data set manageable in GIS; (3) creation of a bare earth digital elevation model (DEM) for each set of scans using ArcMap; and (4) utilization of Geomorphic Change Detection (GCD) software to generate DEMs of Difference (DODs) from subsequent terrestrial laser scans. Preliminary results from three flooding events indicate significant erosional activity at all field sites. Slumps were observed at two bluffs following spring melt and freeze/thaw cycling. Two major precipitation events in late spring and early summer provided a unique opportunity to observe the impact of extreme high flow events on bluff erosion throughout the watershed using TLS technology. 4.75 inches of intermittent rain over a six-day period in late May 2012 (May 23-28) resulted in slumping at many bluffs and one major failure. The ≥100-year flood that occurred on June 19-20 (7.25 inches), 2012 was powerful enough to induce considerable channel change. Slumps occurred at six study sites

  14. Ta Keo Temple Reconstruction Based on Terrestrial Laser Scanning Technology

    NASA Astrophysics Data System (ADS)

    Xi, X.; Wang, C.; Wan, Y. P.; Khuon, K. N.

    2015-08-01

    Ta Keo temple is one of the very famous temple complex of Angkor Wat in northwestern Cambodia. It has been suffering massive collapse and other serious damages in recent years. Nowadays, Terrestrial Laser Scanning(TLS) technology is considered as a wellestablished resource for heritage documentation and protection (Lerma et al, 2008; Reshetyuk, 2009). This paper used TLS to reconstruct Ta Keo Temple. Firstly, we acquired 71 scanning stations of points cloud data with high density and high accuracy, and over one thousand images with high spatial resolution about the temple. Secondly, the raw points cloud data were denoised, reduced and managed efficiently, and registrated using an adjusted ICP algorithm. Thirdly, a triangulation method was used to model most objects. At last, we mapped the texture data into the digital model and a 3-D model of Ta Keo with high accuracy was achieved. The authors focus on large object reconstruction by TLS technology, and pay much attention to the scanning design, multi-station data and the whole project's data registration, and texture mapping and so on. The research result will be useful for Ta Keo restoration, reconstruction and protection. Also, it is a good reference source for large complex buildings reconstruction when using terrestrial laser scanning technology.

  15. Laser-scanning photostimulation of optogenetically targeted forebrain circuits.

    PubMed

    Lee, Charles C; Lam, Ying-Wan; Imaizumi, Kazuo; Sherman, S Murray

    2013-01-01

    The sensory forebrain is composed of intricately connected cell types, of which functional properties have yet to be fully elucidated. Understanding the interactions of these forebrain circuits has been aided recently by the development of optogenetic methods for light-mediated modulation of neuronal activity. Here, we describe a protocol for examining the functional organization of forebrain circuits in vitro using laser-scanning photostimulation of channelrhodopsin, expressed optogenetically via viral-mediated transfection. This approach also exploits the utility of cre-lox recombination in transgenic mice to target expression in specific neuronal cell types. Following transfection, neurons are physiologically recorded in slice preparations using whole-cell patch clamp to measure their evoked responses to laser-scanning photostimulation of channelrhodopsin expressing fibers. This approach enables an assessment of functional topography and synaptic properties. Morphological correlates can be obtained by imaging the neuroanatomical expression of channelrhodopsin expressing fibers using confocal microscopy of the live slice or post-fixed tissue. These methods enable functional investigations of forebrain circuits that expand upon more conventional approaches. PMID:24430760

  16. Fine Deformation Monitoring of Ancient Building Based on Terrestrial Laser Scanning Technologies

    NASA Astrophysics Data System (ADS)

    Wei, Zhou; Huadong, Guo; Qi, Li; Tianhua, Hong

    2014-03-01

    Laser scanning technology has been widely used to build high-precision three dimensional models in the preservation of ancient buildings. In this paper, we take the Tower of Buddhist Incense in the Summer Palace as our research subject. Combining laser scanning technologies with close-range photogrammetry, GIS and virtual reality technologies, we acquired comprehensive and high accuracy geospatial data of the tower, and built the 3D models with an average measurement error of a single point less than 2 millimeters and a registration error of 3D data less than 5 millimeters. After data registration of the whole tower with high-precision, deformation monitoring was conducted. Having been repaired many times, the cross-sections of the tower's pillars are not in a circular shape. In order to know the dip and dip direction of each pillar exactly, ellipse fitting algorithm was used to calculate the location of the centre of every pillar. And then, the coordinates of the pillars' centre points, the major and minor axes of the ellipses, and rotation angles were calculated. The technologies and methodology used in this paper could significantly contribute towards the long-term protection of endangered cultural relics using measurements and modelling with high-levels of scientific precision.

  17. Imaging of calcium wave propagation in guinea-pig ventricular cell pairs by confocal laser scanning microscopy.

    PubMed

    Takamatsu, T; Minamikawa, T; Kawachi, H; Fujita, S

    1991-08-01

    We describe here the use of a confocal laser scanning microscope for imaging fast dynamic changes of the intracellular calcium ion concentration ([Ca2+]i) in isolated ventricular cell pairs. The scanning apparatus of our system, paired galvanometer mirrors, can perform narrow band scanning of an area of interest at a high temporal resolution of less than 70 msec per image. The actual [Ca2+]i is obtained directly through the fluorescence intensity of injected fluo-3, which responds to changes of [Ca2+]i in optically sectioned unit volumes of the cell. Images of the calcium wave obtained during propagation between paired cells revealed that the wavefront is constant in shape and propagates at constant velocity without any delay at the cell-to-cell junction. The confocal laser scanning microscope with depth-discriminating ability is a valuable tool for taking pictures of the sequence of biological events in living cells. PMID:1782671

  18. Three-dimensional image of hepatocellular carcinoma under confocal laser scanning microscope

    PubMed Central

    Zhang, Wang-Hai; Zhu, Shi-Neng; Lu, Shi-Lun; Huang, Ya-Lin; Zhao, Peng

    2000-01-01

    AIM: To investigate the application of confocal laser scanning microscopy (CLSM) in tumor pathology and three-dimensional (3-D) reconstruction by CLSM in pathologic specimens of hepatocellular carcinoma (HCC). METHODS: The 30 μm thick sections were cut from the paraffin-embedded tissues of HCC, hyperplasia and normal liver, stained with DNA fluorescent probe YOYO-1 iodide and examined by CLSM to collect optical sections of nuclei and 3-D images reconstructed. RESULTS: HCC displayed chaotic arrangement of carcinoma cell nuclei, marked pleomorphism, indented and irregular nuclear surface, and irregular and coarse chromatin texture. CONCLUSION: The serial optical tomograms of CLSM can be used to create 3-D reconstruction of cancer cell nuclei. Such 3-D impressions might be helpful or even essential in making an accurate diagnosis. PMID:11819594

  19. Visualization of microcrack anisotropy in granite affected by afault zone, using confocal laser scanning microscope

    SciTech Connect

    Onishi, Celia T.; Shimizu, Ichiko

    2004-01-02

    Brittle deformation in granite can generate a fracture system with different patterns. Detailed fracture analyses at both macroscopic and microscopic scales, together with physical property data from a drill-core, are used to classify the effects of reverse fault deformation in four domains: (1) undeformed granite, (2) fractured granite with cataclastic seams, (3) fractured granite from the damage zone, and (4) foliated cataclasite from the core of the fault. Intact samples from two orthogonal directions, horizontal (H) and vertical (V), from the four domains indicate a developing fracture anisotropy toward the fault, which is highly developed in the damage zone. As a specific illustration of this phenomenon, resin impregnation, using a confocal laser scanning microscope (CLSM) technique is applied to visualize the fracture anisotropy developed in the Toki Granite, Japan. As a result, microcrack networks have been observed to develop in H sections and elongate open cracks in V sections, suggesting that flow pathways can be determined by deformation.

  20. Road Orthophoto/dtm Generation from Mobile Laser Scanning

    NASA Astrophysics Data System (ADS)

    Vallet, B.; Papelard, J.-P.

    2015-08-01

    This paper proposes a pipeline to produce road orthophoto and DTM from Mobile Laser Scanning (MLS). For the ortho, modern laser scanners provide a reflectance information allowing for high quality grayscale images, at a much finer resolution than aerial photography can offer. For DTM, MLS offers a much higher accuracy and density than aerial products. This increased precision and resolution leverages new applications for both ortho and DEM. The first task is to filter ground vs non ground, then an interpolation is conducted to build image tiles from the filtered points. Finally, multiple layers are registered and blended to allow for seamless fusion. Our proposed approach achieves high quality products and scaling up is demonstrated.

  1. An automated microfluidic sample preparation system for laser scanning cytometry.

    PubMed

    Wu, Eric; Menon, Vidya; Geddie, William; Sun, Yu

    2011-04-01

    Laser scanning cytometry (LSC) is emerging as a clinical tool. In one application a "Clatch" slide, named after the inventor, is used in conjunction with LSC for cell surface marker immunophenotyping of patient samples. The slide requires time consuming and laborious pipetting steps, making a test tedious and prone to handling errors. The Clatch slide also uses a significant number of cells, limiting the number of analyses on paucicellular samples. This paper presents an automated microfluidic system consisting of a control circuit, a microfluidic system, and an aluminum frame, capable of performing immunophenotyping procedures. This prototype system reduces 36 pipetting steps to 1, reduces the amount of cell sample from 180 μL to 56 μL, and shortens the time used by technicians.

  2. Laser-scanning photoacoustic microscopy with ultrasonic phased array transducer.

    PubMed

    Zheng, Fan; Zhang, Xiangyang; Chiu, Chi Tat; Zhou, Bill L; Shung, K Kirk; Zhang, Hao F; Jiao, Shuliang

    2012-11-01

    In this paper, we report our latest progress on proving the concept that ultrasonic phased array can improve the detection sensitivity and field of view (FOV) in laser-scanning photoacoustic microscopy (LS-PAM). A LS-PAM system with a one-dimensional (1D) ultrasonic phased array was built for the experiments. The 1D phased array transducer consists of 64 active elements with an overall active dimension of 3.2 mm × 2 mm. The system was tested on imaging phantom and mouse ear in vivo. Experiments showed a 15 dB increase of the signal-to-noise ratio (SNR) when beamforming was employed compared to the images acquired with each single element. The experimental results demonstrated that ultrasonic phased array can be a better candidate for LS-PAM in high sensitivity applications like ophthalmic imaging.

  3. Confocal laser scanning microscopy with spatiotemporal structured illumination.

    PubMed

    Gao, Peng; Nienhaus, G Ulrich

    2016-03-15

    Confocal laser scanning microscopy (CLSM), which is widely utilized in the biological and biomedical sciences, is limited in spatial resolution due to diffraction to about half the light wavelength. Here we have combined structured illumination with CLSM to enhance its spatial resolution. To this end, we have used a spatial light modulator (SLM) to generate fringe patterns of different orientations and phase shifts in the excitation spot without any mechanical movement. We have achieved 1.8 and 1.7 times enhanced lateral and axial resolutions, respectively, by synthesizing the object spectrum along different illumination directions. This technique is thus a promising tool for high-resolution morphological or fluorescence imaging, especially in deep tissue. PMID:26977667

  4. Airborne Laser Scanning and Image Processing Techniques for Archaeological Prospection

    NASA Astrophysics Data System (ADS)

    Faltýnová, M.; Nový, P.

    2014-06-01

    Aerial photography was, for decades, an invaluable tool for archaeological prospection, in spite of the limitation of this method to deforested areas. The airborne laser scanning (ALS) method can be nowadays used to map complex areas and suitable complement earlier findings. This article describes visualization and image processing methods that can be applied on digital terrain models (DTMs) to highlight objects hidden in the landscape. Thanks to the analysis of visualized DTM it is possible to understand the landscape evolution including the differentiation between natural processes and human interventions. Different visualization methods were applied on a case study area. A system of parallel tracks hidden in a forest and its surroundings - part of old route called "Devil's Furrow" near the town of Sázava was chosen. The whole area around well known part of Devil's Furrow has not been prospected systematically yet. The data from the airborne laser scanning acquired by the Czech Office for Surveying, Mapping and Cadastre was used. The average density of the point cloud was approximately 1 point/m2 The goal of the project was to visualize the utmost smallest terrain discontinuities, e.g. tracks and erosion furrows, which some were not wholly preserved. Generally we were interested in objects that are clearly not visible in DTMs displayed in the form of shaded relief. Some of the typical visualization methods were tested (shaded relief, aspect and slope image). To get better results we applied image-processing methods that were successfully used on aerial photographs or hyperspectral images in the past. The usage of different visualization techniques on one site allowed us to verify the natural character of the southern part of Devil's Furrow and find formations up to now hidden in the forests.

  5. Urban Tree Classification Using Full-Waveform Airborne Laser Scanning

    NASA Astrophysics Data System (ADS)

    Koma, Zs.; Koenig, K.; Höfle, B.

    2016-06-01

    Vegetation mapping in urban environments plays an important role in biological research and urban management. Airborne laser scanning provides detailed 3D geodata, which allows to classify single trees into different taxa. Until now, research dealing with tree classification focused on forest environments. This study investigates the object-based classification of urban trees at taxonomic family level, using full-waveform airborne laser scanning data captured in the city centre of Vienna (Austria). The data set is characterised by a variety of taxa, including deciduous trees (beeches, mallows, plane trees and soapberries) and the coniferous pine species. A workflow for tree object classification is presented using geometric and radiometric features. The derived features are related to point density, crown shape and radiometric characteristics. For the derivation of crown features, a prior detection of the crown base is performed. The effects of interfering objects (e.g. fences and cars which are typical in urban areas) on the feature characteristics and the subsequent classification accuracy are investigated. The applicability of the features is evaluated by Random Forest classification and exploratory analysis. The most reliable classification is achieved by using the combination of geometric and radiometric features, resulting in 87.5% overall accuracy. By using radiometric features only, a reliable classification with accuracy of 86.3% can be achieved. The influence of interfering objects on feature characteristics is identified, in particular for the radiometric features. The results indicate the potential of using radiometric features in urban tree classification and show its limitations due to anthropogenic influences at the same time.

  6. Resolution enhancement of two-photon microscopy via intensity-modulated laser scanning structured illumination.

    PubMed

    Yeh, Chia-Hua; Chen, Szu-Yu

    2015-03-20

    Conventional structured illumination microscopy (SIM) with wide-field illumination is an applicable tool to provide resolution enhancement. And yet its applications in thick specimens are still full of challenges. By combing the structured illumination concept with two-photon excitation, a laser scanning two-photon structured illumination microscope (LSTP-SIM) was constructed to gain ∼1.42-fold lateral resolution enhancement in contrast to two-photon fluorescence microscopy. With a point-scanning geometry, an acoustic-optical modulator was used to modulate temporally the excitation intensity in order to produce the structured illumination pattern. The theoretical models of image formation and image reconstruction were clearly established. Simulation and experiments were both performed to show the capability of this system to enhance the lateral resolution. Combined with the inherent optical sectioning power of the two-photon excitation, LSTP-SIM would have the potential for applications in optically-thick specimens. PMID:25968516

  7. A semi-automatic multiple view texture mapping for the surface model extracted by laser scanning

    NASA Astrophysics Data System (ADS)

    Zhang, Zhichao; Huang, Xianfeng; Zhang, Fan; Chang, Yongmin; Li, Deren

    2008-12-01

    Laser scanning is an effective way to acquire geometry data of the cultural heritage with complex architecture. After generating the 3D model of the object, it's difficult to do the exactly texture mapping for the real object. we take effort to create seamless texture maps for a virtual heritage of arbitrary topology. Texture detail is acquired directly from the real object in a light condition as uniform as we can make. After preprocessing, images are then registered on the 3D mesh by a semi-automatic way. Then we divide the mesh into mesh patches overlapped with each other according to the valid texture area of each image. An optimal correspondence between mesh patches and sections of the acquired images is built. Then, a smoothing approach is proposed to erase the seam between different images that map on adjacent mesh patches, based on texture blending. The obtained result with a Buddha of Dunhuang Mogao Grottoes is presented and discussed.

  8. Cell depth imaging by point laser scanning fluorescence microscopy with an optical disk pickup head

    NASA Astrophysics Data System (ADS)

    Tsai, Rung-Ywan; Chen, Jung-Po; Lee, Yuan-Chin; Chiang, Hung-Chih; Cheng, Chih-Ming; Huang, Chun-Chieh; Huang, Tai-Ting; Cheng, Chung-Ta; Tiao, Golden

    2015-09-01

    A compact, cost-effective, and position-addressable digital laser scanning microscopy (DLSM) instrument is made using a commercially available Blu-ray disc read-only memory (BD-ROM) pickup head. Fluorescent cell images captured by DLSM have resolutions of 0.38 µm. Because of the position-addressable function, multispectral fluorescence cell images are captured using the same sample slide with different excitation laser sources. Specially designed objective lenses with the same working distance as the image-capturing beam are used for the different excitation laser sources. By accurately controlling the tilting angles of the sample slide or by moving the collimator lens of the image-capturing beam, the fluorescence cell images along different depth positions of the sample are obtained. Thus, z-section images with micrometer-depth resolutions are achievable.

  9. Estimation of big sagebrush leaf area index with terrestrial laser scanning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A remote-sensing technique is need to bridge the gap between airborne laser scanning (ALS) and ground-based field techniques for accurately assessing leaf area index (LAI) in sparsely vegetated landscapes like sagebrush steppe. Terrestrial laser scanning (TLS) was used to measure structural variable...

  10. Multispectral Analysis of Indigenous Rock Art Using Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Skoog, B.; Helmholz, P.; Belton, D.

    2016-06-01

    Multispectral analysis is a widely used technique in the photogrammetric and remote sensing industry. The use of Terrestrial Laser Scanning (TLS) in combination with imagery is becoming increasingly common, with its applications spreading to a wider range of fields. Both systems benefit from being a non-contact technique that can be used to accurately capture data regarding the target surface. Although multispectral analysis is actively performed within the spatial sciences field, its extent of application within an archaeological context has been limited. This study effectively aims to apply the multispectral techniques commonly used, to a remote Indigenous site that contains an extensive gallery of aging rock art. The ultimate goal for this research is the development of a systematic procedure that could be applied to numerous similar sites for the purpose of heritage preservation and research. The study consisted of extensive data capture of the rock art gallery using two different TLS systems and a digital SLR camera. The data was combined into a common 2D reference frame that allowed for standard image processing to be applied. An unsupervised k-means classifier was applied to the multiband images to detect the different types of rock art present. The result was unsatisfactory as the subsequent classification accuracy was relatively low. The procedure and technique does however show potential and further testing with different classification algorithms could possibly improve the result significantly.

  11. Scan mirrors relay for high resolution laser scanning systems

    NASA Astrophysics Data System (ADS)

    Kessler, David

    2014-09-01

    Two dimensional beam deflection is often required in medical laser scanning systems such as OCT or confocal microscopy. Commonly two linear galvo mirrors are used for performance in terms of their large apertures and scan angles. The galvo mirrors are placed at the vicinity of entrance pupil of the scan lens with a "displacement distance" separating them. This distance limits the scan fields and/or reduces the effective aperture of the scan lens. Another option is to use a beam or pupil relay, and image one galvo mirror onto the other. However, beam (or pupil) relays are notoriously complicated, expensive and can add significant aberrations. This paper discusses a simple, all reflective, diffraction limited, color corrected, beam relay, capable of large scan angles and large deflecting mirrors. The design is based on a unique combination of an Offner configuration with a Schmidt aspheric corrector. The design is highly corrected up to large scan mirrors and large scan angles down to milliwaves of aberrations. It allows significantly larger scan field and or scan lenses with higher numerical aperture as compared with scanners using galvos separated by the displacement distance. While this relay is of exceptionally high performance, it has one element located where the beam is focused which may present a problem for high power lasers. Thus modifications of the above design are introduced where the beam is focused in mid air thus making it usable for high power systems such including laser marking and fabrication systems.

  12. Pedestrian Detection by Laser Scanning and Depth Imagery

    NASA Astrophysics Data System (ADS)

    Barsi, A.; Lovas, T.; Molnar, B.; Somogyi, A.; Igazvolgyi, Z.

    2016-06-01

    Pedestrian flow is much less regulated and controlled compared to vehicle traffic. Estimating flow parameters would support many safety, security or commercial applications. Current paper discusses a method that enables acquiring information on pedestrian movements without disturbing and changing their motion. Profile laser scanner and depth camera have been applied to capture the geometry of the moving people as time series. Procedures have been developed to derive complex flow parameters, such as count, volume, walking direction and velocity from laser scanned point clouds. Since no images are captured from the faces of pedestrians, no privacy issues raised. The paper includes accuracy analysis of the estimated parameters based on video footage as reference. Due to the dense point clouds, detailed geometry analysis has been conducted to obtain the height and shoulder width of pedestrians and to detect whether luggage has been carried or not. The derived parameters support safety (e.g. detecting critical pedestrian density in mass events), security (e.g. detecting prohibited baggage in endangered areas) and commercial applications (e.g. counting pedestrians at all entrances/exits of a shopping mall).

  13. Multispectral Airborne Laser Scanning for Automated Map Updating

    NASA Astrophysics Data System (ADS)

    Matikainen, Leena; Hyyppä, Juha; Litkey, Paula

    2016-06-01

    During the last 20 years, airborne laser scanning (ALS), often combined with multispectral information from aerial images, has shown its high feasibility for automated mapping processes. Recently, the first multispectral airborne laser scanners have been launched, and multispectral information is for the first time directly available for 3D ALS point clouds. This article discusses the potential of this new single-sensor technology in map updating, especially in automated object detection and change detection. For our study, Optech Titan multispectral ALS data over a suburban area in Finland were acquired. Results from a random forests analysis suggest that the multispectral intensity information is useful for land cover classification, also when considering ground surface objects and classes, such as roads. An out-of-bag estimate for classification error was about 3% for separating classes asphalt, gravel, rocky areas and low vegetation from each other. For buildings and trees, it was under 1%. According to feature importance analyses, multispectral features based on several channels were more useful that those based on one channel. Automatic change detection utilizing the new multispectral ALS data, an old digital surface model (DSM) and old building vectors was also demonstrated. Overall, our first analyses suggest that the new data are very promising for further increasing the automation level in mapping. The multispectral ALS technology is independent of external illumination conditions, and intensity images produced from the data do not include shadows. These are significant advantages when the development of automated classification and change detection procedures is considered.

  14. Laser Scanning System for Pressure and Temperature Paints

    NASA Technical Reports Server (NTRS)

    Sullivan, John

    1997-01-01

    Acquiring pressure maps of aerodynamic surfaces is very important for improving and validating the performance of aerospace vehicles. Traditional pressure measurements are taken with pressure taps embedded in the model surface that are connected to transducers. While pressure taps allow highly accurate measurements to be acquired, they do have several drawbacks. Pressure taps do not give good spatial resolution due to the need for individual pressure tubes, compounded by limited space available inside models. Also, building a model proves very costly if taps are needed because of the large amount of labor necessary to drill, connect and test each one. The typical cost to install one tap is about $200. Recently, a new method for measuring pressure on aerodynamic surfaces has been developed utilizing a technology known as pressure sensitive paints (PSP). Using PSP, pressure distributions can be acquired optically with high spatial resolution and simple model preparation. Flow structures can be easily visualized using PSP, but are missed using low spatial resolution arrays of pressure taps. PSP even allows pressure distributions to be found on rotating machinery where previously this has been extremely difficult or even impossible. The goal of this research is to develop a laser scanning system for use with pressure sensitive paints that allows accurate pressure measurements to be obtained on various aerodynamic surfaces ranging from wind tunnel models to high speed jet engine compressor blades.

  15. Street environment change detection from mobile laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Xiao, Wen; Vallet, Bruno; Brédif, Mathieu; Paparoditis, Nicolas

    2015-09-01

    Mobile laser scanning (MLS) has become a popular technique for road inventory, building modelling, infrastructure management, mobility assessment, etc. Meanwhile, due to the high mobility of MLS systems, it is easy to revisit interested areas. However, change detection using MLS data of street environment has seldom been studied. In this paper, an approach that combines occupancy grids and a distance-based method for change detection from MLS point clouds is proposed. Unlike conventional occupancy grids, our occupancy-based method models space based on scanning rays and local point distributions in 3D without voxelization. A local cylindrical reference frame is presented for the interpolation of occupancy between rays according to the scanning geometry. The Dempster-Shafer theory (DST) is utilized for both intra-data evidence fusion and inter-data consistency assessment. Occupancy of reference point cloud is fused at the location of target points and then the consistency is evaluated directly on the points. A point-to-triangle (PTT) distance-based method is combined to improve the occupancy-based method. Because it is robust to penetrable objects, e.g. vegetation, which cause self-conflicts when modelling occupancy. The combined method tackles irregular point density and occlusion problems, also eliminates false detections on penetrable objects.

  16. Multi-Pass Approach for Mobile Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Nolan, J.; Eckels, R.; Evers, M.; Singh, R.; Olsen, M. J.

    2015-08-01

    Mobile Terrestrial Laser Scanning (MTLS) has been utilised for an increasing number of corridor surveys. Current MTLS surveys require that many targets be placed along the corridor to monitor the MTLS trajectory's accuracy. These targets enable surveyors to directly evaluate the magnitude of GNSS errors at regular intervals and can also be used to adjust the trajectory to the survey control. However, this "Multi-Target" approach (MTA) is an onerous task that can significantly reduce efficiency. It also is inconvenient to the travelling public, as lanes are often blocked and traffic slowed to permit surveyors to work safely along the road corridor. This paper introduces a "Multi-Pass" approach (MPA), which minimises the number of targets required for monitoring the GNSS-controlled trajectory while still maintaining strict engineering accuracies. MPA uses the power of multiple, independent MTLS passes with different GNSS constellations to generate a "Control Polyline" from the point cloud for the corridor. The Control Polyline can be considered as a statistically valid survey measurement and be incorporated in a network adjustment to strengthen a control network by identifying outliers. Results from a test survey at the MTLS course maintained by the Oregon Department of Transportation illustrate the effectiveness of this approach.

  17. Quantification of telomere length by FISH and laser scanning cytometry

    NASA Astrophysics Data System (ADS)

    Mahoney, John E.; Sahin, Ergun; Jaskelioff, Mariela; Chin, Lynda; DePinho, Ronald A.; Protopopov, Alexei I.

    2008-02-01

    Telomeres play a critical role in the maintenance of chromosomal stability. Telomere erosion, coupled with loss of DNA damage checkpoint function, results in genomic instability that promotes the development of cancer. The critical role of telomere dynamics in cancer has motivated the development of technologies designed to monitor telomere reserves in a highly quantitative and high-throughput manner in humans and model organisms. To this end, we have adapted and modified two established technologies, telomere-FISH and laser scanning cytometry. Specifically, we have produced a number of enhancements to the iCys LSC (CompuCyte) package including software updates, use of 60X dry objectives, and increased spatial resolution by 0.2 um size of stage steps. In addition, the 633 nm HeNe laser was replaced with a 532 nm green diode laser to better match the viewing options. Utilization of telomere-deficient mouse cells with short dysfunctional telomeres and matched telomerase reconstituted cultures demonstrated significantly higher mean integral specific fluorescence values for mTR transfectants relative to empty vector controls: 4.485M vs. 1.362M (p<0.0001). Histograms of average telomere intensities for individual cells were obtained and demonstrated intercellular heterogeneity in telomere lengths. The validation of the approach derives from a strong correlation between iCys LSC values and Southern blotting. This validated method greatly increases our experimental throughput and objectivity.

  18. Footprint Map Partitioning Using Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Xiong, B.; Oude Elberink, S.; Vosselman, G.

    2016-06-01

    Nowadays many cities and countries are creating their 3D building models for a better daily management and smarter decision making. The newly created 3D models are required to be consistent with existing 2D footprint maps. Thereby the 2D maps are usually combined with height data for the task of 3D reconstruction. Many buildings are often composed by parts that are discontinuous over height. Building parts can be reconstructed independently and combined into a complete building. Therefore, most of the state-of-the-art work on 3D building reconstruction first decomposes a footprint map into parts. However, those works usually change the footprint maps for easier partitioning and cannot detect building parts that are fully inside the footprint polygon. In order to solve those problems, we introduce two methodologies, one more dependent on height data, and the other one more dependent on footprints. We also experimentally evaluate the two methodologies and compare their advantages and disadvantages. The experiments use Airborne Laser Scanning (ALS) data and two vector maps, one with 1:10,000 scale and another one with 1:500 scale.

  19. Laser scanning dental probe for endodontic root canal treatment

    NASA Astrophysics Data System (ADS)

    Blank, Molly A. B.; Friedrich, Michal; Hamilton, Jeffrey D.; Lee, Peggy; Berg, Joel; Seibel, Eric J.

    2011-03-01

    Complications that arise during endodontic procedures pose serious threats to the long-term integrity and health of the tooth. Potential complexities of root canals include residual pulpal tissue, cracks, mesial-buccal 2 and accessory canals. In the case of a failed root canal, a successful apicoectomy can be jeopardized by isthmuses, accessory canals, and root microfracture. Confirming diagnosis using a small imaging probe would allow proper treatment and prevent retreatment of endodontic procedures. An ultrathin and flexible laser scanning endoscope of 1.2 to 1.6mm outer diameter was used in vitro to image extracted teeth with varied root configurations. Teeth were opened using a conventional bur and high speed drill. Imaging within the opened access cavity clarified the location of the roots where canal filing would initiate. Although radiographs are commonly used to determine the root canal size, position, and shape, the limited 2D image perspective leaves ambiguity that could be clarified if used in conjunction with a direct visual imaging tool. Direct visualization may avoid difficulties in locating the root canal and reduce the number of radiographs needed. A transillumination imaging device with the separated illumination and light collection functions rendered cracks visible in the prepared teeth that were otherwise indiscernible using reflected visible light. Our work demonstrates that a small diameter endoscope with high spatial resolution may significantly increase the efficiency and success of endodontic procedures.

  20. Imaging anisotropy using differential polarization laser scanning confocal microscopy.

    PubMed

    Steinbach, Gábor; Pomozi, István; Zsiros, Ottó; Menczel, László; Garab, Gyozo

    2009-01-01

    We have constructed differential polarization (DP) attachments to a laser scanning microscope (LSM) for imaging the main DP quantities of anisotropic microscopic objects. The DP-LSM operates with high-frequency modulation and subsequent demodulation and displays the main DP quantities pixel by pixel. These, for linearly polarized light, include: (i) linear birefringence (LB), which is exhibited by structurally and/or optically anisotropic material; (ii) linear dichroism (LD), which carries information on the anisotropic distribution of the molecules, i.e. of their absorbance transition dipole vectors, in the sample; (iii) fluorescence-detected LD (FDLD), which carries the same information for fluorescent dyes upon excitations with two orthogonally polarized light beams; (iv) anisotropy of the fluorescence emission (r), excited with non-polarized light, which is determined by the distribution of the emission transition dipole vectors in the sample and is analogous with LD and (v) the degree of polarization of the fluorescence emission (P), excited with polarized light, which depends on the depolarization of the emission e.g. due to the rotation of molecules during their excitation lifetimes. In fluorescence regimes, the DP images can be recorded in the confocal regime of the microscope, which thus warrants good spatial resolution and the possibility of mapping the anisotropy in three dimensions. In this paper, we outline the design and technical realization of our DP-LSM and give a few examples on DP imaging of different biological samples.

  1. Detection of windthrown trees using airborne laser scanning

    NASA Astrophysics Data System (ADS)

    Nyström, Mattias; Holmgren, Johan; Fransson, Johan E. S.; Olsson, Håkan

    2014-08-01

    In this study, a method has been developed for the detection of windthrown trees under a forest canopy, using the difference between two elevation models created from the same high density (65 points/m2) airborne laser scanning data. The difference image showing objects near the ground was created by subtracting a standard digital elevation model (DEM) from a more detailed DEM created using an active surface algorithm. Template matching was used to automatically detect windthrown trees in the difference image. The 54 ha study area is located in hemi-boreal forest in southern Sweden (Lat. 58°29‧ N, Long. 13°38‧ E) and is dominated by Norway spruce (Picea abies) with 3.5% deciduous species (mostly birch) and 1.7% Scots pine (Pinus sylvestris). The result was evaluated using 651 field measured windthrown trees. At individual tree level, the detection rate was 38% with a commission error of 36%. Much higher detection rates were obtained for taller trees; 89% of the trees taller than 27 m were detected. For pine the individual tree detection rate was 82%, most likely due to the more easily visible stem and lack of branches. When aggregating the results to 40 m square grid cells, at least one tree was detected in 77% of the grid cells which according to the field measurements contained one or more windthrown trees.

  2. Automatic analysis for neuron by confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Satou, Kouhei; Aoki, Yoshimitsu; Mataga, Nobuko; Hensh, Takao K.; Taki, Katuhiko

    2005-12-01

    The aim of this study is to develop a system that recognizes both the macro- and microscopic configurations of nerve cells and automatically performs the necessary 3-D measurements and functional classification of spines. The acquisition of 3-D images of cranial nerves has been enabled by the use of a confocal laser scanning microscope, although the highly accurate 3-D measurements of the microscopic structures of cranial nerves and their classification based on their configurations have not yet been accomplished. In this study, in order to obtain highly accurate measurements of the microscopic structures of cranial nerves, existing positions of spines were predicted by the 2-D image processing of tomographic images. Next, based on the positions that were predicted on the 2-D images, the positions and configurations of the spines were determined more accurately by 3-D image processing of the volume data. We report the successful construction of an automatic analysis system that uses a coarse-to-fine technique to analyze the microscopic structures of cranial nerves with high speed and accuracy by combining 2-D and 3-D image analyses.

  3. Laser-scan cytometry: a new tool for clinical diagnostics

    NASA Astrophysics Data System (ADS)

    Maerz, Holger K.; Baumgartner, Adolf; Hambsch, Joerg; Hennig, Bert; Nuesse, Michael; Schmid, Thomas; Schneider, Peter; Zotz, Rainer; Tarnok, Attila

    1999-04-01

    The common usage of flow cytometry (FCM) in research and clinical diagnostic is limited by the lack visualizing the fluorescence labelled cells. The Laser Scanning Cytometer (LSC) enables multicolor cytometric measurements on a slide featuring relocation of single cells for further investigation via brightfield and fluorescence microscopy. Additionally, it is possible to capture these images for documentation. In a FISH application, the LSC was successfully used for automated scoring techniqeus for evaluating the frequency of aneuploid sperm in humans and mice. In just 30 minutes, we were able to acquire more than 15,000 sperms, a task which normally takes more than a day. After relocation, genetic defects were identified and confirmed via fluorescence microscopy. In an on going study, we investigate via the LSC the remain of a new radiopaque material for high resolution echocardiography in the blood circulation. At first the result exhibited that the radiopaque material is endocysed by leukocytes just after application but is still detectable via echocardiography for up to 40 minutes. In conclusion, with the additional data acquisition by the LSC, it is possible to perform further detailed information from very small samples. Therefore, we are working up to now on developing new methods to introduce the LSC in our clinical diagnostic of neonates undergoing cardiac surgery.

  4. Delineation of individual tree crowns for mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Wu, Rosen; Chen, Yiping; Wen, Chenglu; Wang, Cheng; Li, Jonathan

    2016-03-01

    The information of individual trees plays an important role in urban surveying and mapping. With the development of Light Detection and Ranging (LiDAR) technology, 3-Dimenisonal (3D) structure of trees can be generated in point clouds with high spatial resolution and accuracy. Individual tree segmentations are used to derive tree structural attributes such as tree height, crown diameter, stem position etc. In this study, a framework is proposed to take advantage of the detailed structures of tree crowns which are represented in the mobile laser scanning (MLS) data. This framework consists of five steps: (1) Automatically detect and remove ground points using RANSAC; (2) Compress all the above ground points to image grid with 3D knowledge reserved; (3) Simplify and remove unqualified grids; (4) Find tree peaks using a heuristic searching method; (5) Delineate the individual tree crowns by applying a modified watershed method. In an experiment on the point clouds on Xiamen Island, China, individual tree crowns from MLS point cloud data are successfully extracted.

  5. Quantifying Snow Volume Uncertainty from Repeat Terrestrial Laser Scanning Observations

    NASA Astrophysics Data System (ADS)

    Gadomski, P. J.; Hartzell, P. J.; Finnegan, D. C.; Glennie, C. L.; Deems, J. S.

    2014-12-01

    Terrestrial laser scanning (TLS) systems are capable of providing rapid, high density, 3D topographic measurements of snow surfaces from increasing standoff distances. By differencing snow surface with snow free measurements within a common scene, snow depths and volumes can be estimated. These data can support operational water management decision-making when combined with measured or modeled snow densities to estimate basin water content, evaluate in-situ data, or drive operational hydrologic models. In addition, change maps from differential TLS scans can also be used to support avalanche control operations to quantify loading patterns for both pre-control planning and post-control assessment. However, while methods for computing volume from TLS point cloud data are well documented, a rigorous quantification of the volumetric uncertainty has yet to be presented. Using repeat TLS data collected at the Arapahoe Basin Ski Area in Summit County, Colorado, we demonstrate the propagation of TLS point measurement and cloud registration uncertainties into 3D covariance matrices at the point level. The point covariances are then propagated through a volume computation to arrive at a single volume uncertainty value. Results from two volume computation methods are compared and the influence of data voids produced by occlusions examined.

  6. Estimation of forest parameters using airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Cohen, J.

    2015-12-01

    Methods for the estimation of forest characteristics by airborne laser scanning (ALS) data have been introduced by several authors. Tree height (TH) and canopy closure (CC) describing the forest properties can be used in forest, construction and industry applications, as well as research and decision making. The National Land Survey has been collecting ALS data from Finland since 2008 to generate a nationwide high resolution digital elevation model. Although this data has been collected in leaf-off conditions, it still has the potential to be utilized in forest mapping. A method where this data is used for the estimation of CC and TH in the boreal forest region is presented in this paper. Evaluation was conducted in eight test areas across Finland by comparing the results with corresponding Multi-Source National Forest Inventory (MS-NFI) datasets. The ALS based CC and TH maps were generally in a good agreement with the MS-NFI data. As expected, deciduous forests caused some underestimation in CC and TH, but the effect was not major in any of the test areas. The processing chain has been fully automated enabling fast generation of forest maps for different areas.

  7. Flow cytometric and laser scanning microscopic approaches in epigenetics research.

    PubMed

    Szekvolgyi, Lorant; Imre, Laszlo; Minh, Doan Xuan Quang; Hegedus, Eva; Bacso, Zsolt; Szabo, Gabor

    2009-01-01

    Our understanding of epigenetics has been transformed in recent years by the advance of technological possibilities based primarily on a powerful tool, chromatin immunoprecipitation (ChIP). However, in many cases, the detection of epigenetic changes requires methods providing a high-throughput (HTP) platform. Cytometry has opened a novel approach for the quantitative measurement of molecules, including PCR products, anchored to appropriately addressed microbeads (Pataki et al. 2005. Cytometry 68, 45-52). Here we show selected examples for the utility of two different cytometry-based platforms of epigenetic analysis: ChIP-on-beads, a flow-cytometric test of local histone modifications (Szekvolgyi et al. 2006. Cytometry 69, 1086-1091), and the laser scanning cytometry-based measurement of global epigenetic modifications that might help predict clinical behavior in different pathological conditions. We anticipate that such alternative tools may shortly become indispensable in clinical practice, translating the systematic screening of epigenetic tags from basic research into routine diagnostics of HTP demand.

  8. Three-dimensional imaging of interphase cell nuclei with laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Boecker, Wilfried; Radtke, Thomas; Streffer, Christian

    1998-10-01

    During the past decade 3D image processing has become an important key component in biological research mainly due to two different developments. The first is based on an optical instrument, the so-called confocal laser scanning microscope, allowing optical sectioning of the biological specimen. The second is a biological preparatory method, the so-called FISH-technique (Fluorescence-In-Situ- Hybridization), allowing labeling of certain cellular and sub-cellular compartments with highly specific fluorescent dyes. Both methods make it possible to investigate the 3D biological framework within cells and nuclei. Image acquisition with confocal laser scanning microscopy must deal with different limits of resolution along and across the optical axis. Although lateral resolution is about 0.7 times better than in non-confocal arrangements, axial resolution is more than 3 - 4 times poorer than that of the lateral (depending on the pinhole size). For 3D reconstruction it is desirable to improve axial resolution in order to provide nearly identical image information across the 3D specimen space. This presentation will give an overview of some of the most popular restoration and deblurring algorithms used in 3D image microscopy. After 3D image restoration, segmentation of certain details of the cell structure is usually the next step in image processing. We compared two different kinds of algorithms for segmentation of chromosome territories in interphase cell nuclei. One is based on Mathematical Morphology, the other on Split & Merge methods. The segmented image regions provided the basis for chromosome domain reconstruction as well as for regional localization for subsequent quantitative measurements. As a result the chromatin density within certain chromosome domains as well as some terminal DNA sequences (telomere signals) could be measured.

  9. Laser Scanning in Engineering Surveying: Methods of Measurement and Modeling of Structures

    NASA Astrophysics Data System (ADS)

    Lenda, Grzegorz; Uznański, Andrzej; Strach, Michał; Lewińska, Paulina

    2016-06-01

    The study is devoted to the uses of laser scanning in the field of engineering surveying. It is currently one of the main trends of research which is developed at the Department of Engineering Surveying and Civil Engineering at the Faculty of Mining Surveying and Environmental Engineering of AGH University of Science and Technology in Krakow. They mainly relate to the issues associated with tower and shell structures, infrastructure of rail routes, or development of digital elevation models for a wide range of applications. These issues often require the use of a variety of scanning techniques (stationary, mobile), but the differences also regard the planning of measurement stations and methods of merging point clouds. Significant differences appear during the analysis of point clouds, especially when modeling objects. Analysis of the selected parameters is already possible basing on ad hoc measurements carried out on a point cloud. However, only the construction of three-dimensional models provides complete information about the shape of structures, allows to perform the analysis in any place and reduces the amount of the stored data. Some structures can be modeled in the form of simple axes, sections, or solids, for others it becomes necessary to create sophisticated models of surfaces, depicting local deformations. The examples selected for the study allow to assess the scope of measurement and office work for a variety of uses related to the issue set forth in the title of this study. Additionally, the latest, forward-looking technology was presented - laser scanning performed from Unmanned Aerial Vehicles (drones). Currently, it is basically in the prototype phase, but it might be expected to make a significant progress in numerous applications in the field of engineering surveying.

  10. Tree classification with fused mobile laser scanning and hyperspectral data.

    PubMed

    Puttonen, Eetu; Jaakkola, Anttoni; Litkey, Paula; Hyyppä, Juha

    2011-01-01

    Mobile Laser Scanning data were collected simultaneously with hyperspectral data using the Finnish Geodetic Institute Sensei system. The data were tested for tree species classification. The test area was an urban garden in the City of Espoo, Finland. Point clouds representing 168 individual tree specimens of 23 tree species were determined manually. The classification of the trees was done using first only the spatial data from point clouds, then with only the spectral data obtained with a spectrometer, and finally with the combined spatial and hyperspectral data from both sensors. Two classification tests were performed: the separation of coniferous and deciduous trees, and the identification of individual tree species. All determined tree specimens were used in distinguishing coniferous and deciduous trees. A subset of 133 trees and 10 tree species was used in the tree species classification. The best classification results for the fused data were 95.8% for the separation of the coniferous and deciduous classes. The best overall tree species classification succeeded with 83.5% accuracy for the best tested fused data feature combination. The respective results for paired structural features derived from the laser point cloud were 90.5% for the separation of the coniferous and deciduous classes and 65.4% for the species classification. Classification accuracies with paired hyperspectral reflectance value data were 90.5% for the separation of coniferous and deciduous classes and 62.4% for different species. The results are among the first of their kind and they show that mobile collected fused data outperformed single-sensor data in both classification tests and by a significant margin.

  11. Extracting Rail Track Geometry from Static Terrestrial Laser Scans for Monitoring Purposes

    NASA Astrophysics Data System (ADS)

    Soni, A.; Robson, S.; Gleeson, B.

    2014-06-01

    This paper presents the capabilities of detecting relevant geometry of railway track for monitoring purposes from static terrestrial laser scanning (TLS) systems at platform level. The quality of the scans from a phased based scanner (Scanner A) and a hybrid timeof- flight scanner (Scanner B) are compared by fitting different sections of the track profile to its matching standardised rail model. The various sections of track investigated are able to fit to the model with an RMS of less than 3 mm. Both scanners show that once obvious noise and artefacts have been removed from the data, the most confident fit of the point cloud to the model is the section closest to the scanner position. The results of the fit highlight the potential to use this method as a bespoke track monitoring tool during major redevelopment projects where traditional methods, such as robotic total stations, results in missed information, for example due to passing trains or knocked prisms and must account for offset target locations to compute track parameters.

  12. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE AND RAT OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse and Rat Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research ...

  13. Diffusion of photoacid generators by laser scanning confocal microscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Ping L.; Webber, Stephen E.; Mendenhall, J.; Byers, Jeffrey D.; Chao, Keith K.

    1998-06-01

    Diffusion of the photogenerated acid during the period of time between exposure and development can cause contrast loss and ultimately loss of the latent image. This is especially relevant for chemically amplified photoresists that require a post-exposure baking step, which in turn facilitates acid diffusion due to the high temperature normally employed. It is thus important to develop techniques with good spatial resolution to monitor the photogeneration of acid. More precisely, we need techniques that provide two distinct types of information: spatial resolution on various length scales within the surface layer and also sufficient depth resolution so that one can observe the transition from very surface layer to bulk structure in the polymer blend coated on silicon substrate. Herein laser scanning confocal microscopy is used to evaluate the resist for the first time. We report the use of the confocal microscopy to map the pag/dye distribution in PHS matrices, with both reflectance images and fluorescence images. A laser beam is focused onto a small 3D volume element, termed a voxel. It is typically 200 nm X 200 nm laterally and 800 nm axially. The illuminated voxel is viewed such that only signals emanating from this voxel are detected, i.e., signal from outside the probed voxel is not detected. By adjusting the vertical position of the laser focal point, the voxel can be moved to the designated lateral plane to produce an image. Contrast caused by topology difference between the exposed and unexposed area can be eliminated. Bis-p-butylphenyl iodonium triflat (7% of polyhydroxystyrene) is used as photoacid generators. 5% - 18% (by weight, PHS Mn equals 13 k) resist in PGMEA solution is spin cast onto the treated quartz disk with thickness of 1.4 micrometers , 5 micrometers space/10 micrometers pitch chrome mask is used to generate the pattern with mercury DUV illumination. Fluoresceinamine, the pH-sensitive dye, is also used to enhance the contrast of

  14. Estimation of terracing characteristics from airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Kokalj, Žiga

    2015-04-01

    Agricultural terraces are a fundamental morphological form of the Slovenian landscape. They are present in all of its diverse geographical regions, from Mediterranean and Dinaric hills and plateaus, Alpine mountains and plains, to Pannonian hills. New systematic research based on mapping aerial orthophotos and historical maps revealed previously unrecorded distribution and extent of terracing. However, the extensive overgrowing of the Slovenian countryside in the past century, when forest cover has grown from 40% to more than 60%, hid many of the terraces under a thick forest canopy. This is especially true for the higher and more remote areas where unfavourable natural conditions have coupled with depopulation processes. In such conditions, the only reasonable technique to observe cultural terraces and other remains of past human activities over large areas is airborne laser scanning. With the country-wide airborne lidar data becoming available, many new possibilities for discovery as well as quantitative analyses are becoming available. We explored manual and semiautomatic approaches to obtain terracing characteristics around representative villages of diverse landscape types. Individual terraces can be described with several attributes, such as riser slope gradient, riser height, tread area, length and width, ratio of length and width, altitude, location of the terrace in the thermal band, distance to the settlement, number and type of trees, distance between trees, and number of vineyard rows. Such characteristics can be derived manually, which can be painstakingly slow, but with relative precisions reaching the order of centimetres and decimetres, or semiautomatically, which is much faster, but with worse precision levels, mainly due to various outliers and errors in processing. The success of attribute derivation is highly dependent on raw lidar data acquisition parameters and processing. Manual interpretation has a distinct advantage of the possibility to

  15. Geodetic Imaging of Marsh Surface Elevation with Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Nguyen, C. T.; Starek, M. J.; Gibeaut, J. C.; Lord, A.

    2015-12-01

    The resilience of marshes to a rising sea is dependent on their elevation response. Given the level of precision required to measure minute changes in marsh elevation over time, survey methods have to be adapted to minimize impacts to the sediment surface. Current approaches include Surface Elevation Tables (SETs), which are used to monitor wetland surface change with respect to an in situ vertical benchmark. Although SETs have been proven as an effective technique to track subtle sedimentation rates (< 1 cm/year), they provide a single-point measurement construed to a location with limited to no information on the spatial pattern in marsh elevation response away from the measurement site. Terrestrial Laser Scanning (TLS) offers potential for high definition monitoring of marsh surface evolution. However, several challenges must be overcome in the application of the technology for geodetic imaging of marsh surfaces. These challenges include surface occlusion by dense vegetation, error propagation due to scan co-registration and referencing across time, impacts of scan angle, and filtering of non-ground points. Researchers at Texas A&M University-Corpus Christi conducted a field-survey of a marsh within the Grand Bay National Estuarine Research Reserve using TLS and RTK GPS for comparison. Grand Bay in Mississippi USA is one of the most biologically productive estuarine ecosystems in the Gulf of Mexico. The study region is covered by dense and tall saw-grass that makes it a challenging environment for bare-earth mapping. For this survey, a Riegl VZ-400 TLS (1550 nm wavelength) was utilized. The system is capable of recording multiple returns per a transmitted pulse (up to 15) and provides full-waveform output for signal post-processing to extract returns. The objectives of the study are twofold: 1) examine impacts of TLS survey design, scan angle and scan density on marsh elevation mapping; 2) assess the capabilities of multiple-echo and full-waveform TLS data to

  16. Development of an Online Archive for Terrestrial Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Crosby, Christopher; Lowry, Ben; McWhirter, Jeff; Phillips, David; Meertens, Chuck

    2013-04-01

    The UNAVCO Geodetic Imaging program provides terrestrial laser scanning (TLS) support to the Earth science research community through a TLS instrumentation pool of five scanners, field engineering, data processing, and technical training. As part of this community TLS support role, UNAVCO is responsible for generation of level one (L1) TLS data products and TLS data archive and access. A UNAVCO-organized and US National Science Foundation-funded TLS community workshop held October 2011 in Boulder, Colorado defined many of the challenges and requirements a TLS data archive and access system must address. TLS data acquisition presents unique challenges for metadata, provenance capture, and data archive. TLS datasets are often large and level zero (L0 - raw) data are stored in a variety of proprietary formats, requiring conversion and standardization for access and exchange. Due to the wide range of scientific and engineering objectives that motivate TLS data collection, field methods and collection techniques vary greatly and must be thoroughly documented in project metadata. These challenges make data and metadata capture, preservation, and provenance important objectives for an online TLS archive. To address these challenges, UNAVCO is developing a TLS archive based on the open source RAMADDA platform (http://ramadda.org). The UNAVCO TLS archive will provide online archive of L0 and L1 data products, capture field metadata and data processing workflows for provenance, and store original georeferencing information. In addition, the TLS repository provides on-demand services for simple point cloud visualization, data sub-setting and thinning, and file format (e.g., LAS, ASCII, proprietary) data conversion. The system also offers automation of RINEX processing of GPS data, OPUS and CSRS submission and solution ingestion, and generation of control point lists to streamline georeferencing of TLS point cloud data. Georeferencing metadata and GPS file provenance are

  17. Stop-and-Go Mode: Sensor Manipulation as Essential as Sensor Development in Terrestrial Laser Scanning

    PubMed Central

    Lin, Yi; Hyyppä, Juha; Kukko, Antero

    2013-01-01

    This study was dedicated to illustrating the significance of sensor manipulation in the case of terrestrial laser scanning, which is a field now in quick development. In fact, this quickness was mainly rooted in the emergence of new sensors with better performance, while the implications of sensor manipulation have not been fully recognized by the whole community. For this technical gap, the stop-and-go mapping mode can be reckoned as one of the potential solution plans. Stop-and-go was first proposed to handle the low efficiency of traditional static terrestrial laser scanning, and then, it was re-emphasized to improve the stability of sample collections for the state-of-the-art technology of mobile laser scanning. This work reviewed the previous efforts of trying the stop-and-go mode for improving the performance of static and mobile terrestrial laser scanning and generalized their principles respectively. This work also analyzed its advantages compared to the fully-static and fully-kinematic terrestrial laser scanning, and suggested the plans with more automatic measures for raising the efficacy of terrestrial laser scanning. Overall, this literature review indicated that the stop-and-go mapping mode as a case with generic sense can verify the presumption of sensor manipulation as essential as sensor development. PMID:23799493

  18. Dual-channel laser scanning microscopy for the identification and quantification of proliferating skeletal muscle satellite cells following synergist ablation.

    PubMed Central

    Brotchie, D; Davies, I; Ireland, G; Mahon, M

    1995-01-01

    Proliferating skeletal muscle satellite cells are the source of additional myonuclei which allow skeletal muscle to grow and regenerate. Previously, proliferating satellite cells were identified in situ by techniques which were limited either by tissue processing time or inability to observe complete muscle sections, or by errors made in separating these cells from proliferating nonmyogenic cells. To overcome these problems a new method has been devised for the identification and quantification of proliferating satellite cells in situ by light microscopy. The technique involves dual-channel laser scanning imaging of whole muscle sections for the localisation of both the muscle fibre basal lamina and the cell division marker bromodeoxyuridine. Using this technique satellite cell proliferation was quantified in mouse limb muscle following synergist ablation. Dual-channel laser scanning microscopy allowed precise localisation of proliferating satellite cells in the experimental model and, after 4 d, synergist ablation was shown to have produced significant satellite cell proliferation when compared with contralateral and sham-operated controls. Images Fig. 1 PMID:7649821

  19. Processing of airborne laser scanning data to generate accurate DTM for floodplain wetland

    NASA Astrophysics Data System (ADS)

    Szporak-Wasilewska, Sylwia; Mirosław-Świątek, Dorota; Grygoruk, Mateusz; Michałowski, Robert; Kardel, Ignacy

    2015-10-01

    Structure of the floodplain, especially its topography and vegetation, influences the overland flow and dynamics of floods which are key factors shaping ecosystems in surface water-fed wetlands. Therefore elaboration of the digital terrain model (DTM) of a high spatial accuracy is crucial in hydrodynamic flow modelling in river valleys. In this study the research was conducted in the unique Central European complex of fens and marshes - the Lower Biebrza river valley. The area is represented mainly by peat ecosystems which according to EU Water Framework Directive (WFD) are called "water-dependent ecosystems". Development of accurate DTM in these areas which are overgrown by dense wetland vegetation consisting of alder forest, willow shrubs, reed, sedges and grass is very difficult, therefore to represent terrain in high accuracy the airborne laser scanning data (ALS) with scanning density of 4 points/m2 was used and the correction of the "vegetation effect" on DTM was executed. This correction was performed utilizing remotely sensed images, topographical survey using the Real Time Kinematic positioning and vegetation height measurements. In order to classify different types of vegetation within research area the object based image analysis (OBIA) was used. OBIA allowed partitioning remotely sensed imagery into meaningful image-objects, and assessing their characteristics through spatial and spectral scale. The final maps of vegetation patches that include attributes of vegetation height and vegetation spectral properties, utilized both the laser scanning data and the vegetation indices developed on the basis of airborne and satellite imagery. This data was used in process of segmentation, attribution and classification. Several different vegetation indices were tested to distinguish different types of vegetation in wetland area. The OBIA classification allowed correction of the "vegetation effect" on DTM. The final digital terrain model was compared and examined

  20. a New Approach for Segmentation-Based Texturing of Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Lari, Z.; Habib, A.

    2015-02-01

    In recent years, laser scanning systems have been recognized as a fast and accurate technology for the acquisition of high density spatial data. The advent of these systems has reduced the cost and increased the availability of accurate 3D data for mapping, modelling, and monitoring applications. The original laser scanning data does not explicitly provide meaningful information about the characteristics of the scanned surfaces. Therefore, reliable processing procedures are applied for information extraction from these datasets. However, the derived surfaces through laser scanning data processing cannot be effectively interpreted due to the lack of spectral information. To resolve this problem, a new texturing procedure is introduced in this paper to improve the interpretability of laser scanning-derived surfaces using spectral information from overlapping imagery. In this texturing approach, individual planar regions, derived through a laser scanning data segmentation procedure, are textured using the available imagery. This texturing approach, which aims to overcome the computational inefficiency of the previously-developed point-based texturing techniques, is implemented in three steps. In the first step, the visibility of the segmented planar regions in the available imagery is checked and a list of appropriate images for texturing each planar region is established. An occlusion detection procedure is then performed to identify the parts of the segmented regions which are occluding/being occluded by other regions in the field of view of the utilized images. In the second step, visible parts of planar regions are decomposed into parts which should be textured using individual images. Finally, a rendering procedure is performed to texture these parts using available images. Experimental results from real laser scanning dataset and overlapping imagery demonstrate the feasibility of the proposed approach for texturing laser scanning-derived surfaces using images.

  1. Three-dimensional visualization of termite (Apicotermitinae) enteric valve using confocal laser scanning microscopy.

    PubMed

    Host, B; Twyffels, L; Roisin, Y; Vanderwinden, J-M

    2014-08-01

    Humivorous termites are dominant members of tropical rainforest soil communities. In the soil-feeding subfamily Apicotermitinae (Termitidae), the enteric valve connecting the first section of the hindgut to the paunch often displays a complex sclerotized armature everted towards the lumen of the paunch. This structure is central in termite taxonomy but its function remains hypothetical. Here, we evaluate the potential of confocal laser scanning microscopy to provide detailed imaging of the valve of Anoplotermes parvus, by comparison with bright-field microscopy and scanning electron microscopy. We detected a strong far-red emission of the enteric valve armature that sharply contrasted with the surrounding tissues, providing a convenient method to highlight minute structural elements of the valve and its three-dimensional structure. The method is easy to use and is applicable to standard archival material as demonstrated by images of enteric valves of four other Apicotermitinae species. It may represent a valuable asset for the study of termite enteric valves, for the purpose of taxonomy or functional morphology. PMID:24947115

  2. A statistical pixel intensity model for segmentation of confocal laser scanning microscopy images.

    PubMed

    Calapez, Alexandre; Rosa, Agostinho

    2010-09-01

    Confocal laser scanning microscopy (CLSM) has been widely used in the life sciences for the characterization of cell processes because it allows the recording of the distribution of fluorescence-tagged macromolecules on a section of the living cell. It is in fact the cornerstone of many molecular transport and interaction quantification techniques where the identification of regions of interest through image segmentation is usually a required step. In many situations, because of the complexity of the recorded cellular structures or because of the amounts of data involved, image segmentation either is too difficult or inefficient to be done by hand and automated segmentation procedures have to be considered. Given the nature of CLSM images, statistical segmentation methodologies appear as natural candidates. In this work we propose a model to be used for statistical unsupervised CLSM image segmentation. The model is derived from the CLSM image formation mechanics and its performance is compared to the existing alternatives. Results show that it provides a much better description of the data on classes characterized by their mean intensity, making it suitable not only for segmentation methodologies with known number of classes but also for use with schemes aiming at the estimation of the number of classes through the application of cluster selection criteria.

  3. Apoplastic pH in corn root gravitropism: a laser scanning confocal microscopy measurement.

    PubMed

    Taylor, D P; Slattery, J; Leopold, A C

    1996-05-01

    The ability to measure the pH of the apoplast in situ is of special interest as a test of the cell wall acidification theory. Optical sectioning of living seedlings of corn roots using the laser scanning confocal microscope (LSCM) permits us to make pH measurements in living tissue. The pH of the apoplast of corn roots was measured by this method after infiltration with Cl-NERF, a pH-sensitive dye, along with Texas Red Dextran 3000, a pH-insensitive dye, as an internal standard. In the elongation zone of corn roots, the mean apoplastic pH was 4.9. Upon gravitropic stimulation, the pH on the convex side of actively bending roots was 4.5. The lowering of the apoplastic pH by 0.4 units appears to be sufficient to account for the increased growth on that side. This technique provides site-specific evidence for the acid growth theory of cell elongation. The LSCM permits measurements of the pH of living tissues, and has a sensitivity of approximately 0.2 pH units. PMID:11539373

  4. The application of dermal papillary rings in dermatology by in vivo confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Xiang, W. Z.; Xu, A. E.; Xu, J.; Bi, Z. G.; Shang, Y. B.; Ren, Q. S.

    2010-08-01

    Confocal laser scanning microscopy (CLSM) allows noninvasive visualization of human skin in vivo, without needing to fix or section the tissue. Melanocytes and pigmented keratinocytes at the level of the basal layer form bright dermal papillary rings which are readily amenable to identify in confocal images. Our purpose was to explore the role of dermal papillary rings in assessment of lesion location, the diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. Seventy-one patients were imaged with the VivaScope 1500 reflectance confocal microscope provided by Lucid, Inc. The results indicate that dermal papillary rings can assess the location of lesion; the application of dermal papillary rings can provide diagnostic support and differential diagnosis for vitiligo, nevus depigmentosus, tinea versicolor, halo nevus, common nevi, and assess the therapeutic efficacy of NBUVB phototherapy plus topical 0.1 percent tacrolimus ointment for vitiligo. In conclusion, our findings indicate that the dermal papillary rings play an important role in the assessment the location of lesion, diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. CLSM may be a promising tool for noninvasive examination in dermatology. However, larger studies are needed to expand the application of dermal papillary rings in dermatology.

  5. A statistical pixel intensity model for segmentation of confocal laser scanning microscopy images.

    PubMed

    Calapez, Alexandre; Rosa, Agostinho

    2010-09-01

    Confocal laser scanning microscopy (CLSM) has been widely used in the life sciences for the characterization of cell processes because it allows the recording of the distribution of fluorescence-tagged macromolecules on a section of the living cell. It is in fact the cornerstone of many molecular transport and interaction quantification techniques where the identification of regions of interest through image segmentation is usually a required step. In many situations, because of the complexity of the recorded cellular structures or because of the amounts of data involved, image segmentation either is too difficult or inefficient to be done by hand and automated segmentation procedures have to be considered. Given the nature of CLSM images, statistical segmentation methodologies appear as natural candidates. In this work we propose a model to be used for statistical unsupervised CLSM image segmentation. The model is derived from the CLSM image formation mechanics and its performance is compared to the existing alternatives. Results show that it provides a much better description of the data on classes characterized by their mean intensity, making it suitable not only for segmentation methodologies with known number of classes but also for use with schemes aiming at the estimation of the number of classes through the application of cluster selection criteria. PMID:20363677

  6. Coupling airborne laser scanning and acoustic Doppler current profiler data to model stream rating curves

    NASA Astrophysics Data System (ADS)

    Lam, N.; Lyon, S. W.; Kean, J. W.

    2015-12-01

    The rating curve enables the translation of water depth into discharge through a reference cross section. Errors in estimating stream channel geometry can therefore result in increased discharge uncertainty. This study investigates coupling national-scale airborne laser scanning (ALS) and acoustic Doppler current profiler (ADCP) bathymetric survey data for generating stream rating curves. Specifically, stream channel geometries were generated from coupled ALS and ADCP scanning data collected for a well-monitored site located in northern Sweden. These data were used to define the hydraulic geometry required by a physically-based 1-D hydraulic model. The results of our study demonstrate that the effects of potential scanning data errors on the model generated rating curve were less than the uncertainties due to stream gauging measurements and empirical rating curve fitting. Further analysis of the ALS data showed that an overestimation of the streambank elevation (the main scanning data error) was primarily due to vegetation that could be adjusted for through a root-mean-square-error bias correction. We consider these findings encouraging as hydrometric agencies can potentially leverage national-scale ALS and ADCP instrumentation to reduce the cost and effort required for maintaining and establish rating curves at gauging stations.

  7. Development of a high speed laser scanning confocal microscope with an acquisition rate up to 200 frames per second.

    PubMed

    Choi, S; Kim, P; Boutilier, R; Kim, M Y; Lee, Y J; Lee, H

    2013-10-01

    There has been an increasing interest for observing fast biological phenomena such as cell movements in circulations and action potentials. The laser scanning confocal microscopy offers a good spatial resolution and optical sectioning ability to observe various in vivo animal models. We developed a high speed laser scanning confocal microscope capable of acquiring 512 by 512 pixel images at 200 fps (frames per second). We have incorporated a fast rotating polygonal scanning mirror with 128 facets for the X-axis scanner. In order to increase the throughput of the Y-axis scanner, we applied a bi-directional scanning method for vertical scanning. This made it possible to scan along the Y-axis two times during each scanner motion cycle. For the image acquisition, we used a custom photomultiplier tube amplifier with a broad frequency band. In addition, custom imaging software was written for the new microscope. In order to verify the acquisition speed of the developed confocal microscope, a resolution target moving at a series of constant speeds and a sedated mouse with slight movements due to heartbeats were observed. By comparing successive frames, the frame acquisition speeds were calculated.

  8. Deformation Monitoring of Motorway Underpasses Using Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Puente, I.; González-Jorge, H.; Riveiro, B.; Arias, P.

    2012-07-01

    voussoirs ranging between 1 mm and 5 mm. These deformations are under the tolerances predicted by the structure and confirm the success in the construction works developed. The laser scanning and the post-processing algorithms here developed appear as an easy methodology to make deformation monitoring of underpass structures and guarantee the load capacity of the structure.

  9. A novel quality control procedure for the evaluation of laser scanning data segmentation

    NASA Astrophysics Data System (ADS)

    Lari, Z.; Al-Durgham, K.; Habib, A.

    2014-11-01

    Over the past few years, laser scanning systems have been acknowledged as the leading tools for the collection of high density 3D point cloud over physical surfaces for many different applications. However, no interpretation and scene classification is performed during the acquisition of these datasets. Consequently, the collected data must be processed to extract the required information. The segmentation procedure is usually considered as the fundamental step in information extraction from laser scanning data. So far, various approaches have been developed for the segmentation of 3D laser scanning data. However, none of them is exempted from possible anomalies due to disregarding the internal characteristics of laser scanning data, improper selection of the segmentation thresholds, or other problems during the segmentation procedure. Therefore, quality control procedures are required to evaluate the segmentation outcome and report the frequency of instances of expected problems. A few quality control techniques have been proposed for the evaluation of laser scanning segmentation. These approaches usually require reference data and user intervention for the assessment of segmentation results. In order to resolve these problems, a new quality control procedure is introduced in this paper. This procedure makes hypotheses regarding potential problems that might take place in the segmentation process, detects instances of such problems, quantifies the frequency of these problems, and suggests possible actions to remedy them. The feasibility of the proposed approach is verified through quantitative evaluation of planar and linear/cylindrical segmentation outcome from two recently-developed parameter-domain and spatial-domain segmentation techniques.

  10. Assessment of DNA replication in central nervous system by Laser Scanning Cytometry

    NASA Astrophysics Data System (ADS)

    Lenz, Dominik; Mosch, Birgit; Bocsi, Jozsef; Arendt, Thomas; Tárnok, Attila

    2004-07-01

    μIn neurons of patients with Alzheimers's disease (AD) signs of cell cycle re-entry as well as polyploidy have been reported1, 2, indicating that the entire or a part of the genome of the neurons is duplicated before its death but mitosis is not initiated so that the cellular DNA content remains tetraploid. It was concluded, that this imbalance is the direct cause of the neuronal loss in AD3. Manual counting of polyploidal cells is possible but time consuming and possibly statistically insufficient. The aim of this study was to develop an automated method that detects the neuronal DNA content abnormalities with Laser Scanning Cytometry (LSC).Frozen sections of formalin-fixed brain tissue of AD patients and control subjects were labelled with anti-cyclin B and anti-NeuN antibodies. Immunolabelling was performed using Cy5- and Cy2-conjugated secondary antibodies and biotin streptavidin or tyramid signal amplification. In the end sections of 20m thickness were incubated with propidium iodide (PI) (50μg/ml) and covered on slides. For analysis by the LSC PI was used as trigger. Cells identified as neurons by NeuN expression were analyzed for cyclin B expression. Per specimen data of at least 10,000 neurons were acquired. In the frozen brain sections an automated quantification of the amount of nuclear DNA is possible with LSC. The DNA ploidy as well as the cell cycle distribution can be analyzed. A high number of neurons can be scanned and the duration of measuring is shorter than a manual examination. The amount of DNA is sufficiently represented by the PI fluorescence to be able to distinguish between eu- and polyploid neurons.

  11. Development of a 3D laser scanning system for the cavity

    NASA Astrophysics Data System (ADS)

    Chen, Kai; Zhang, Da; Zhang, Yuan Sheng

    2013-06-01

    Serious geological hazard such as the roof fall-rib spalling-closure deformation of the cavity can exert bad influence to mine, even threaten human life. The traditional monitoring ways have some disadvantages, which are difficulties in obtaining data of the cavity, monitoring the unmanned cavity and calculating volume of the cavity accurately. To solve these problems, this paper describes how to develop a high precision 3D laser scanning system, which enables scanning the cavity rapidly, obtaining the same resolution point cloud, calculating volume of the cavity, marking the deformation area correctly and providing visualized environment. At the same time, this device has realized remote control functionality to avoid people to work on the underground. The measurement accuracy of the 3D laser scanning system is +/-2cm. The 3D laser scanning system can be combined with the mine microseism monitoring system to help with the estimation the cavity's stability and improve the effect of cavity monitoring.

  12. Reversible patterning of poly(methylmethacrylate) doped with disperse Red 1 by laser scanning

    SciTech Connect

    Tuma, J.; Lyutakov, O.; Huttel, I.; Slepicka, P.; Svorcik, V.

    2013-09-07

    Thin poly(methylmethacrylate) films doped by or covalently attached to disperse Red 1 acrylate (DR1) were patterned by laser scanning and simultaneous sample movement in confocal microscope. In both cases, periodical structure due to Marangoni effect is created. Modified polymers surfaces were analyzed by FTIR spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. After first stage of patterning, second stage with sample movement in perpendicular direction was applied. Depending on the method of DR1 dotation fishnet structure is obtained or pattern structure disappears. In the latter case, reversibility of pattern formation and erasure by laser scanning was studied.

  13. Single-photon-counting detector for increased sensitivity in two-photon laser scanning microscopy.

    PubMed

    Benninger, Richard K P; Ashby, William J; Ring, Elisabeth A; Piston, David W

    2008-12-15

    We present the use and characterization of a photon-counting detector for increased sensitivity at low signal levels in fluorescence laser scanning microscopy (LSM). Conventional LSM photomultiplier tube detectors utilize analog current integration and thus suffer from excessive noise at low signal levels, introduced during current measurement. In this Letter we describe the implementation of a fast single-photon-counting (SPC) detector on a conventional two-photon laser scanning microscope and detail its use in imaging low fluorescence intensities. We show that for a low photon flux, the SPC detector is shot-noise limited and thus provides increased detection sensitivity compared with analog current integration. PMID:19079484

  14. Morphological and confocal laser scanning microscopic investigations of the adductor muscle-shell interface in scallop.

    PubMed

    Zhao, Che; Ren, Luquan; Liu, Qingping; Liu, Taoran

    2015-09-01

    The challenge of joining dissimilar advanced materials has led researchers around the world to search for new and more efficient solutions. This way, we can highlight the muscle-shell attachment in mollusk, which possessed high strength and toughness. In order to make clear how this "bi-material interface" derives its superior mechanical properties, the morphological features of the adductor muscle scar in Patinopecten yessoensis was investigated by means of confocal laser scanning microscopy (CLSM). This scar area was found to consist of a myostracum with many evenly distributed pit structures and a fracture section with a parallel arranged prism-like structure. The measured values of the distribution density, diameter, and depth of those pit structures were 24 ± 4/49,152 μm2, 7.36 ± 2.47 μm, and 1 ± 0.31 μm respectively. Profile of each pit wall was arc curve without closed angle. Furthermore, CLSM micrographs showed that considerable micro pits (0.1-0.9 μm in diameter) distribute round the pit wall and on the pit bottom. This special micromorphology is the first report on the adductor muscle scar in scallop. In addition, the mineral state and mechanical property of the scar surface was analyzed by XRD and nanoindentation test respectively. In general, the study results presented in this work elucidated that the adductor muscle of P. yessoensis was attached to the shell by insertion of collagen fibers and fibril bundles branched from themselves into pits on the myostracum. This specific connection mechanism can increase the strength of the interface without compromising its ductility and toughness. PMID:26202606

  15. Interaction of maize zein with wheat gluten in composite dough and bread as determined by confocal laser scanning microscopy.

    PubMed

    Bugusu, Betry A; Rajwa, Bartlomiej; Hamaker, Bruce R

    2002-01-01

    Protein body-free maize zein, when mixed at 35 degrees C (above its glass transition temperature range), significantly (p < 0.01) improved the rheological and leavening properties of sorghum-wheat composite flour dough, resulting in improved loaf volume. Confocal laser scanning microscopy was used to observe the structure of zein fibrils and the interaction between zein and gluten proteins in the composite dough and bread systems. Autofluorescence and immunolocalization techniques were used to locate gluten and zein, respectively. Optical sections were collected every 0.4 microm through the samples and digitally processed to produce reconstructed three-dimensional images. Results showed that zein fibrils form an outer layer that intermittently coats the gluten networks, thereby strengthening them. This type of microstructure is able to withstand the pressure exerted by gas cell expansion during yeast fermentation to increase loaf volume.

  16. Penetration of tamoxifen citrate loaded ethosomes and liposomes across human skin: a comparative study with confocal laser scanning microscopy.

    PubMed

    Sarwa, Khomendra K; Suresh, Preeti K; Rudrapal, Mithun; Verma, Vinod K

    2014-01-01

    In the present study, ethosomal and liposomal formulations containing tamoxifen citrate were prepared and evaluated for their penetration properties in human cadaver skin using Franz diffusion cell and confocal laser scanning microscope (CLSM). The results clearly revealed that ethosomal vesicles showed a better drug permeation profile than that of liposomal vesicles. In addition, low fluorescence intensity in CLSM was recorded with liposomes as compared to ethosomes, indicating lower cumulative amount of drug permeation from liposomal vesicles. Furthermore, CLSM showed uniform fluorescence intensity across the entire depth of skin in ethosomal treatment, indicating high penetrability of ethosomal vesicles through human cadaver skin. In contrast, low penetrability of conventional liposomal vesicles was recorded as penetration was limited to the 7(th) section (i.e. upper epidermis layer) of skin as evident from visualization of intact liposomal vesicles in CLSM. PMID:24428443

  17. Penetration of tamoxifen citrate loaded ethosomes and liposomes across human skin: a comparative study with confocal laser scanning microscopy.

    PubMed

    Sarwa, Khomendra K; Suresh, Preeti K; Rudrapal, Mithun; Verma, Vinod K

    2014-01-01

    In the present study, ethosomal and liposomal formulations containing tamoxifen citrate were prepared and evaluated for their penetration properties in human cadaver skin using Franz diffusion cell and confocal laser scanning microscope (CLSM). The results clearly revealed that ethosomal vesicles showed a better drug permeation profile than that of liposomal vesicles. In addition, low fluorescence intensity in CLSM was recorded with liposomes as compared to ethosomes, indicating lower cumulative amount of drug permeation from liposomal vesicles. Furthermore, CLSM showed uniform fluorescence intensity across the entire depth of skin in ethosomal treatment, indicating high penetrability of ethosomal vesicles through human cadaver skin. In contrast, low penetrability of conventional liposomal vesicles was recorded as penetration was limited to the 7(th) section (i.e. upper epidermis layer) of skin as evident from visualization of intact liposomal vesicles in CLSM.

  18. Imaging of oxidative stress at subcellular level by confocal laser scanning microscopy after fluorescent derivatization of cellular carbonyls.

    PubMed Central

    Pompella, A.; Comporti, M.

    1993-01-01

    Confocal laser scanning fluorescence microscopy plus image videoanalysis was used to visualize the tissue areas and the subcellular sites first involved by oxidative stress and lipid peroxidation, in the well-established experimental model of lipid peroxidation induced by haloalkane intoxication in the liver cell. The fluorescent reagent 3-hydroxy-2-naphthoic acid hydrazide was employed to derivativize the carbonyl functions originating from the lipoperoxidative process in situ, in liver cryostat sections from in vivo intoxicated rats, as well as in isolated hepatocytes exposed in vitro to the pro-oxidant action of haloalkanes. The results obtained indicate that: 1) the detection of fluorescent derivatives of carbonyls indeed offers a gain in sensitivity, 2) haloalkane-induced lipid peroxidation in hepatocytes primarily involves the perinuclear endoplasmic reticulum, whereas the plasma membrane and the nuclear compartment are unaffected, and 3) lipid peroxidation also induces an increase of liver autofluorescence. Images Figure 2 Figure 4 PMID:8494040

  19. Uptake and localisation of O-(beta-hydroxyethyl)-rutosides in the venous wall, measured by laser scanning microscopy.

    PubMed

    Neumann, H A; Carlsson, K; Brom, G H

    1992-01-01

    The uptake and localisation of O-(beta-hydroxyethyl)-rutosides (HR) in the venous wall was studied in 8 patients undergoing crossectomy for a varicose long saphenous vein. The fluorescence of cross-sections of the vein wall was measured by laser scanning microscopy, based on the autofluorescence of HR. Four patients (treated group) received 2 x 1.5 g HR IV before surgery, and four (untreated patients) served as controls. Uptake of HR into the veins from treated patients was seen, with a mean fluorescence intensity of 80.9 units compared to 49.4 units in the untreated veins. The increase in fluorescence was clearly demarcated on the endothelial side of the vein wall. It is concluded that HR passes into the vascular wall, where it is localised in the endothelial and sub-endothelial areas.

  20. Microanalysis of dental caries using laser-scanned fluorescence

    NASA Astrophysics Data System (ADS)

    Barron, Joseph R.; Paton, Barry E.; Zakariasen, Kenneth L.

    1992-06-01

    It is well known that enamel and dentin fluoresce when illuminated by short-wavelength optical radiation. Fluorescence emission from carious and non-carious regions of teeth have been studied using a new experimental scanning technique for fluorescence analysis of dental sections. Scanning in 2 dimensions will allow surface maps of dental caries to be created. These surface images are then enhanced using the conventional and newer image processing techniques. Carious regions can be readily identified and contour maps can be used to graphically display the degree of damage on both surfaces and transverse sections. Numerous studies have shown that carious fluorescence is significantly different than non-carious regions. The scanning laser fluorescence spectrometer focuses light from a 25 mW He-Cd laser at 442 nm through an objective lens onto a cross-section area as small as 3 micrometers in diameter. Microtome prepared dental samples 100 micrometers thick are laid flat onto an optical bench perpendicular to the incident beam. The sample is moved under computer control in X & Y with an absolute precision of 0.1 micrometers . The backscattered light is both spatial and wavelength filtered before being measured on a long wavelength sensitized photomultiplier tube. High precision analysis of dental samples allow detailed maps of carious regions to be determined. Successive images allow time studies of caries growth and even the potential for remineralization studies of decalcified regions.

  1. MAMMALIAN APOPTOSIS IN WHOLE NEONATAL OVARIES USING CONFOCAL LASER SCANNING MICROSCOPY

    EPA Science Inventory

    MAMMALIAN APOPTOSIS IN WHOLE NEONATAL OVARIES USING CONFOCAL LASER SCANNING MICROSCOPY

    Robert M. Zucker Susan C. Jeffery and Sally D. Perreault

    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Prot...

  2. Recommendations for the design and the installation of large laser scanning microscopy systems

    NASA Astrophysics Data System (ADS)

    Helm, P. Johannes

    2012-03-01

    Laser Scanning Microscopy (LSM) has since the inventions of the Confocal Scanning Laser Microscope (CLSM) and the Multi Photon Laser Scanning Microscope (MPLSM) developed into an essential tool in contemporary life science and material science. The market provides an increasing number of turn-key and hands-off commercial LSM systems, un-problematic to purchase, set up and integrate even into minor research groups. However, the successful definition, financing, acquisition, installation and effective use of one or more large laser scanning microscopy systems, possibly of core facility character, often requires major efforts by senior staff members of large academic or industrial units. Here, a set of recommendations is presented, which are helpful during the process of establishing large systems for confocal or non-linear laser scanning microscopy as an effective operational resource in the scientific or industrial production process. Besides the description of technical difficulties and possible pitfalls, the article also illuminates some seemingly "less scientific" processes, i.e. the definition of specific laboratory demands, advertisement of the intention to purchase one or more large systems, evaluation of quotations, establishment of contracts and preparation of the local environment and laboratory infrastructure.

  3. Evaluation of a laser scanning sensor for variable-rate tree sprayer development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate canopy measurement capabilities are prerequisites to automate variable-rate sprayers. A 270° radial range laser scanning sensor was tested for its scanning accuracy to detect tree canopy profiles. Signals from the laser sensor and a ground speed sensor were processed with an embedded comput...

  4. Orientation of airborne laser scanning point clouds with multi-view, multi-scale image blocks.

    PubMed

    Rönnholm, Petri; Hyyppä, Hannu; Hyyppä, Juha; Haggrén, Henrik

    2009-01-01

    Comprehensive 3D modeling of our environment requires integration of terrestrial and airborne data, which is collected, preferably, using laser scanning and photogrammetric methods. However, integration of these multi-source data requires accurate relative orientations. In this article, two methods for solving relative orientation problems are presented. The first method includes registration by minimizing the distances between of an airborne laser point cloud and a 3D model. The 3D model was derived from photogrammetric measurements and terrestrial laser scanning points. The first method was used as a reference and for validation. Having completed registration in the object space, the relative orientation between images and laser point cloud is known. The second method utilizes an interactive orientation method between a multi-scale image block and a laser point cloud. The multi-scale image block includes both aerial and terrestrial images. Experiments with the multi-scale image block revealed that the accuracy of a relative orientation increased when more images were included in the block. The orientations of the first and second methods were compared. The comparison showed that correct rotations were the most difficult to detect accurately by using the interactive method. Because the interactive method forces laser scanning data to fit with the images, inaccurate rotations cause corresponding shifts to image positions. However, in a test case, in which the orientation differences included only shifts, the interactive method could solve the relative orientation of an aerial image and airborne laser scanning data repeatedly within a couple of centimeters.

  5. D Model of AL Zubarah Fortress in Qatar - Terrestrial Laser Scanning VS. Dense Image Matching

    NASA Astrophysics Data System (ADS)

    Kersten, T.; Mechelke, K.; Maziull, L.

    2015-02-01

    In September 2011 the fortress Al Zubarah, built in 1938 as a typical Arabic fortress and restored in 1987 as a museum, was recorded by the HafenCity University Hamburg using terrestrial laser scanning with the IMAGER 5006h and digital photogrammetry for the Qatar Museum Authority within the framework of the Qatar Islamic Archaeology and Heritage Project. One goal of the object recording was to provide detailed 2D/3D documentation of the fortress. This was used to complete specific detailed restoration work in the recent years. From the registered laser scanning point clouds several cuttings and 2D plans were generated as well as a 3D surface model by triangle meshing. Additionally, point clouds and surface models were automatically generated from digital imagery from a Nikon D70 using the open-source software Bundler/PMVS2, free software VisualSFM, Autodesk Web Service 123D Catch beta, and low-cost software Agisoft PhotoScan. These outputs were compared with the results from terrestrial laser scanning. The point clouds and surface models derived from imagery could not achieve the same quality of geometrical accuracy as laser scanning (i.e. 1-2 cm).

  6. Initial Tests and Accuracy Assesment of a Compact Mobile Laser Scanning System

    NASA Astrophysics Data System (ADS)

    Julge, K.; Ellmann, A.; Vajakas, T.; Kolka, R.

    2016-06-01

    Mobile laser scanning (MLS) is a faster and cost-effective alternative to static laser scanning, even though there is a slight trade-off in accuracy. This contribution describes a compact mobile laser scanning system mounted on a vehicle. The technical parameters of the used system components, i.e. a small LIDAR sensor Velodyne VLP-16 and a dual antenna GNSS/INS system Advanced Navigation Spatial Dual, are reviewed, along with the integration of these components for spatial data acquisition. Calculation principles of 3D coordinates from the real-time data of all the involved sensors are discussed. The field tests were carried out in a controlled environment of a parking lot and at different velocities. Experiments were carried out to test the ability of the GNSS/INS system to cope with difficult conditions, e.g. sudden movements due to cornering or swerving. The accuracy of the resulting MLS point cloud is evaluated with respect to high-accuracy static terrestrial laser scanning data. Problems regarding combining LIDAR, GNSS and INS sensors are outlined, as well as the initial accuracy assessments. Initial tests revealed errors related to insufficient quality of inertial data and a need for the trajectory post-processing calculations. Although this study was carried out while the system was mounted on a car, there is potential for operating the system on an unmanned aerial vehicle, all-terrain vehicle or in a backpack mode due to its relatively compact size.

  7. a Study about Terrestrial Laser Scanning for Reconstruction of Precast Concrete to Support Qlassic Assessment

    NASA Astrophysics Data System (ADS)

    Aziz, M. A.; Idris, K. M.; Majid, Z.; Ariff, M. F. M.; Yusoff, A. R.; Luh, L. C.; Abbas, M. A.; Chong, A. K.

    2016-09-01

    Nowadays, terrestrial laser scanning shows the potential to improve construction productivity by measuring the objects changes using real-time applications. This paper presents the process of implementation of an efficient framework for precast concrete using terrestrial laser scanning that enables contractors to acquire accurate data and support Quality Assessment System in Construction (QLASSIC). Leica Scanstation C10, black/white target, Autodesk Revit and Cyclone software were used in this study. The results were compared with the dimensional of based model precast concrete given by the company as a reference with the AutoDesk Revit model from the terrestrial laser scanning data and conventional method (measuring tape). To support QLASSIC, the tolerance dimensions of cast in-situ & precast elements is +10mm / -5mm. The results showed that the root mean square error for a Revit model is 2.972mm while using measuring tape is 13.687mm. The accuracy showed that terrestrial laser scanning has an advantage in construction jobs to support QLASSIC.

  8. Three-dimensional visualization and quantitation of fibrin in solid tumors by confocal laser scanning microscopy.

    PubMed

    Biggerstaff, J; Amirkhosravi, A; Francis, J L

    1997-10-01

    Fibrin forms part of the stroma essential for growth of solid tumors. Anticoagulants reduce primary tumor growth and tumor metastasis in murine and some human tumors. These effects may be partly mediated by reduction of intra-tumor fibrin, although there are no quantitative data to support this hypothesis. We therefore evaluated the effect of warfarin on fibrin deposition in a subcutaneously (s.c.) implanted murine tumor using confocal laser scanning microscopy (CLSM). AJ mice received no treatment (n = 6) or sodium warfarin (3.5 mg/L in drinking water, n = 5). All animals received 2 x 10(6) syngeneic Neuro2a neuroblastoma cells s.c. After 14 days, primary tumors were excised and placed in liquid nitrogen. Warfarin treatment resulted in a small, but significant (P < 0.05), decrease in wet tumor weight. Frozen sections (20 microns) were incubated with goat anti-mouse fibrin(ogen) or normal goat serum (isotypic control) and stained with FITC-conjugated rabbit anti-goat antibody. Using a Multiprobe 2001 CLSM (Molecular Dynamics, Sunnyvale, CA), 20 serial optical sections were taken from five, randomly chosen, high power fields (60x objective) for each slide. A threshold excluded all fluorescence except that from structural components within the tumor stroma (fibrin). The volume of fibrin in each section series was determined, and the percentage of tumor volume occupied by fibrin calculated. Intra- and inter-assay variation were assessed on serial frozen tumor sections from an untreated animal. The percentage fibrin volume was not significantly different among or within experiments, indicating that the procedure was reproducible. In controls, the median (range) volume occupied by fibrin was 8.1% (2.4-22.3%), whereas in anticoagulated animals, this was reduced to 3.7% (0.4-14.0%; P < 0.001). This is the first quantitative demonstration that warfarin reduces fibrin deposition in solid tumors. We conclude that three-dimensional CLSM is useful for the quantitation of

  9. Three-dimensional visualization and quantitation of fibrin in solid tumors by confocal laser scanning microscopy.

    PubMed

    Biggerstaff, J; Amirkhosravi, A; Francis, J L

    1997-10-01

    Fibrin forms part of the stroma essential for growth of solid tumors. Anticoagulants reduce primary tumor growth and tumor metastasis in murine and some human tumors. These effects may be partly mediated by reduction of intra-tumor fibrin, although there are no quantitative data to support this hypothesis. We therefore evaluated the effect of warfarin on fibrin deposition in a subcutaneously (s.c.) implanted murine tumor using confocal laser scanning microscopy (CLSM). AJ mice received no treatment (n = 6) or sodium warfarin (3.5 mg/L in drinking water, n = 5). All animals received 2 x 10(6) syngeneic Neuro2a neuroblastoma cells s.c. After 14 days, primary tumors were excised and placed in liquid nitrogen. Warfarin treatment resulted in a small, but significant (P < 0.05), decrease in wet tumor weight. Frozen sections (20 microns) were incubated with goat anti-mouse fibrin(ogen) or normal goat serum (isotypic control) and stained with FITC-conjugated rabbit anti-goat antibody. Using a Multiprobe 2001 CLSM (Molecular Dynamics, Sunnyvale, CA), 20 serial optical sections were taken from five, randomly chosen, high power fields (60x objective) for each slide. A threshold excluded all fluorescence except that from structural components within the tumor stroma (fibrin). The volume of fibrin in each section series was determined, and the percentage of tumor volume occupied by fibrin calculated. Intra- and inter-assay variation were assessed on serial frozen tumor sections from an untreated animal. The percentage fibrin volume was not significantly different among or within experiments, indicating that the procedure was reproducible. In controls, the median (range) volume occupied by fibrin was 8.1% (2.4-22.3%), whereas in anticoagulated animals, this was reduced to 3.7% (0.4-14.0%; P < 0.001). This is the first quantitative demonstration that warfarin reduces fibrin deposition in solid tumors. We conclude that three-dimensional CLSM is useful for the quantitation of

  10. Laser scanning measurements on trees for logging harvesting operations.

    PubMed

    Zheng, Yili; Liu, Jinhao; Wang, Dian; Yang, Ruixi

    2012-01-01

    Logging harvesters represent a set of high-performance modern forestry machinery, which can finish a series of continuous operations such as felling, delimbing, peeling, bucking and so forth with human intervention. It is found by experiment that during the process of the alignment of the harvesting head to capture the trunk, the operator needs a lot of observation, judgment and repeated operations, which lead to the time and fuel losses. In order to improve the operation efficiency and reduce the operating costs, the point clouds for standing trees are collected with a low-cost 2D laser scanner. A cluster extracting algorithm and filtering algorithm are used to classify each trunk from the point cloud. On the assumption that every cross section of the target trunk is approximate a standard circle and combining the information of an Attitude and Heading Reference System, the radii and center locations of the trunks in the scanning range are calculated by the Fletcher-Reeves conjugate gradient algorithm. The method is validated through experiments in an aspen forest, and the optimized calculation time consumption is compared with the previous work of other researchers. Moreover, the implementation of the calculation result for automotive capturing trunks by the harvesting head during the logging operation is discussed in particular. PMID:23012543

  11. Laser scanning measurements on trees for logging harvesting operations.

    PubMed

    Zheng, Yili; Liu, Jinhao; Wang, Dian; Yang, Ruixi

    2012-01-01

    Logging harvesters represent a set of high-performance modern forestry machinery, which can finish a series of continuous operations such as felling, delimbing, peeling, bucking and so forth with human intervention. It is found by experiment that during the process of the alignment of the harvesting head to capture the trunk, the operator needs a lot of observation, judgment and repeated operations, which lead to the time and fuel losses. In order to improve the operation efficiency and reduce the operating costs, the point clouds for standing trees are collected with a low-cost 2D laser scanner. A cluster extracting algorithm and filtering algorithm are used to classify each trunk from the point cloud. On the assumption that every cross section of the target trunk is approximate a standard circle and combining the information of an Attitude and Heading Reference System, the radii and center locations of the trunks in the scanning range are calculated by the Fletcher-Reeves conjugate gradient algorithm. The method is validated through experiments in an aspen forest, and the optimized calculation time consumption is compared with the previous work of other researchers. Moreover, the implementation of the calculation result for automotive capturing trunks by the harvesting head during the logging operation is discussed in particular.

  12. Two-photon excitation in laser scanning fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Strickler, James H.; Webb, Watt W.

    1991-04-01

    Simultaneous absorption of two red photons from a strongly focused subpicosecond colliding pulse mode4ocked dye laser stimulates visible fluorescence emission from fluorophores having their normal absorption in the ultraviolet1. The quadratic increase of the two-photon excitation rate with excitation intensity restricts fluorescence emission to the focal volume thus providing the same depth resolution as does confocal microscopy. Image degradation due to out of focus backround is thus avoided. Photobleaching and most cellular photodamage are similarly confined to the focus thereby minimizing sample degredation during acquisition of the multiple sections required for 3-d image reconstruction. Fluorescence images of living cells and other thick photolabile fluorescence labled assemblies illustrate the depth discrimination of both two-photon fluorescence excitation and photobleaching. The quadratic intensity dependence of two-photon excitation allows 3-d spatially resolved photochemistry in particular the photolytic release of caged compounds such as neurotransmitters nucleotides fluorescent dyes and second messengers such as 1P3 and Ca. The two-photon release of cased ATP has been measured and release of a caged fluorescent dye has been shown. Point photobleaching and a 3-d " write once read many" optical memory have been demonstrated. Two-photon excitation of photo-initiated polymerization with a sharply focused single beam allows microfabrication of complex structures of arbitrary form. By scanning the focused beam through a liquid polymer with a UV excited initiator it is possible to harden the polymer only at the focus thereby creating

  13. A confocal laser scanning microscope segmentation method applied to magnetic resonance images.

    PubMed

    Anderson, Jeffrey R; Barrett, Steven F

    2008-01-01

    Segmentation is the process of defining distinct objects in an image. A semi-automatic segmentation method has been developed for biological objects that have been recorded with a confocal laser scanning microscope (CLSM). The CLSM produces a sequence of thinly "sliced" images that represent cross-sectional views of the sample containing the object of interest. The cross-sectional representation, or "seed" is created of the object of interest within a single slice of the image stack. The segmentation method uses this "seed" to segment the same object in the adjacent image slice. The new "seed" is used for the next image slice and so on, until the object of interest is segmented in all images of the data set. The segmentation method is based on the idea that the object of interest does not change significantly from one image slice to the next. The segmented information is then used to create 3D renderings of the object. These renderings can be studied and analyzed on the computer screen. Previous work has demonstrated the usefulness of the algorithm as applied to the CLSM images. This paper explores the application of the segmentation method to a standard sequence of magnet resonance imaging (MRI) images. Typical MRI machines can produce impressive images of the human body. The resulting data set is often a sequence, or "stack" of cross-sectional slice images of a particular region of the body. The goal then, is to use the previously described segmentation method on a standard sequence of MRI images. This process will expose limitations with the segmentation method and areas where further work can be directed. This paper illustrates and discusses some of the differences between the data sets that make the current segmentation method inadequate for segmentation of MRI data set. Some of the differences can be corrected with modification of the segmentation algorithm, but other differences are beyond the capabilities of the segmentation method, and can possibly be

  14. The application of laser scanning confocal microscopy to the examination of hairs and textile fibers: an initial investigation.

    PubMed

    Kirkbride, K Paul; Tridico, Silvana R

    2010-02-25

    An initial investigation of the application of laser scanning confocal microscopy to the examination of hairs and fibers has been conducted. This technique allows the production of virtual transverse and longitudinal cross-sectional images of a wide range of hairs and fibers. Special mounting techniques are not required; specimens that have been mounted for conventional microscopy require no further treatment. Unlike physical cross-sectioning, in which it is difficult to produce multiple cross-sections from a single hair or fiber and the process is destructive, confocal microscopy allows the examiner to image the cross-section at any point in the field of view along the hair or fiber and it is non-destructive. Confocal microscopy is a fluorescence-based technique. The images described in this article were collected using only the autofluorescence exhibited by the specimen (i.e. fluorescence staining was not necessary). Colorless fibers generally and hairs required excitation at 405 nm in order to stimulate useful autofluorescence; longer wavelength excitation was suitable for dyed fibers. Although confocal microscopy was found to be generally applicable to the generation virtual transverse cross-sections from a wide range of hairs and fibers, on some occasions the autofluorescence signal was attenuated by heavy pigmentation or the presence of an opaque medulla in hairs, and by heavy delustering or the presence of air-filled voids in the case of fibers. In these situations only partial cross-sections were obtained.

  15. Graph Structure-Based Simultaneous Localization and Mapping Using a Hybrid Method of 2D Laser Scan and Monocular Camera Image in Environments with Laser Scan Ambiguity

    PubMed Central

    Oh, Taekjun; Lee, Donghwa; Kim, Hyungjin; Myung, Hyun

    2015-01-01

    Localization is an essential issue for robot navigation, allowing the robot to perform tasks autonomously. However, in environments with laser scan ambiguity, such as long corridors, the conventional SLAM (simultaneous localization and mapping) algorithms exploiting a laser scanner may not estimate the robot pose robustly. To resolve this problem, we propose a novel localization approach based on a hybrid method incorporating a 2D laser scanner and a monocular camera in the framework of a graph structure-based SLAM. 3D coordinates of image feature points are acquired through the hybrid method, with the assumption that the wall is normal to the ground and vertically flat. However, this assumption can be relieved, because the subsequent feature matching process rejects the outliers on an inclined or non-flat wall. Through graph optimization with constraints generated by the hybrid method, the final robot pose is estimated. To verify the effectiveness of the proposed method, real experiments were conducted in an indoor environment with a long corridor. The experimental results were compared with those of the conventional GMappingapproach. The results demonstrate that it is possible to localize the robot in environments with laser scan ambiguity in real time, and the performance of the proposed method is superior to that of the conventional approach. PMID:26151203

  16. Graph Structure-Based Simultaneous Localization and Mapping Using a Hybrid Method of 2D Laser Scan and Monocular Camera Image in Environments with Laser Scan Ambiguity.

    PubMed

    Oh, Taekjun; Lee, Donghwa; Kim, Hyungjin; Myung, Hyun

    2015-01-01

    Localization is an essential issue for robot navigation, allowing the robot to perform tasks autonomously. However, in environments with laser scan ambiguity, such as long corridors, the conventional SLAM (simultaneous localization and mapping) algorithms exploiting a laser scanner may not estimate the robot pose robustly. To resolve this problem, we propose a novel localization approach based on a hybrid method incorporating a 2D laser scanner and a monocular camera in the framework of a graph structure-based SLAM. 3D coordinates of image feature points are acquired through the hybrid method, with the assumption that the wall is normal to the ground and vertically flat. However, this assumption can be relieved, because the subsequent feature matching process rejects the outliers on an inclined or non-flat wall. Through graph optimization with constraints generated by the hybrid method, the final robot pose is estimated. To verify the effectiveness of the proposed method, real experiments were conducted in an indoor environment with a long corridor. The experimental results were compared with those of the conventional GMappingapproach. The results demonstrate that it is possible to localize the robot in environments with laser scan ambiguity in real time, and the performance of the proposed method is superior to that of the conventional approach. PMID:26151203

  17. Graph Structure-Based Simultaneous Localization and Mapping Using a Hybrid Method of 2D Laser Scan and Monocular Camera Image in Environments with Laser Scan Ambiguity.

    PubMed

    Oh, Taekjun; Lee, Donghwa; Kim, Hyungjin; Myung, Hyun

    2015-07-03

    Localization is an essential issue for robot navigation, allowing the robot to perform tasks autonomously. However, in environments with laser scan ambiguity, such as long corridors, the conventional SLAM (simultaneous localization and mapping) algorithms exploiting a laser scanner may not estimate the robot pose robustly. To resolve this problem, we propose a novel localization approach based on a hybrid method incorporating a 2D laser scanner and a monocular camera in the framework of a graph structure-based SLAM. 3D coordinates of image feature points are acquired through the hybrid method, with the assumption that the wall is normal to the ground and vertically flat. However, this assumption can be relieved, because the subsequent feature matching process rejects the outliers on an inclined or non-flat wall. Through graph optimization with constraints generated by the hybrid method, the final robot pose is estimated. To verify the effectiveness of the proposed method, real experiments were conducted in an indoor environment with a long corridor. The experimental results were compared with those of the conventional GMappingapproach. The results demonstrate that it is possible to localize the robot in environments with laser scan ambiguity in real time, and the performance of the proposed method is superior to that of the conventional approach.

  18. Standalone Terrestrial Laser Scanning for Efficiently Capturing Aec Buildings for As-Built Bim

    NASA Astrophysics Data System (ADS)

    Bassier, M.; Vergauwen, M.; Van Genechten, B.

    2016-06-01

    With the increasing popularity of as-built building models for the architectural, engineering and construction (AEC) industry, the demand for highly accurate and dense point cloud data is rising. The current data acquisition methods are labour intensive and time consuming. In order to compete with indoor mobile mapping systems (IMMS), surveyors are now opting to use terrestrial laser scanning as a standalone solution. However, there is uncertainty about the accuracy of this approach. The emphasis of this paper is to determine the scope for which terrestrial laser scanners can be used without additional control. Multiple real life test cases are evaluated in order to identify the boundaries of this technique. Furthermore, this research presents a mathematical prediction model that provides an indication of the data accuracy given the project dimensions. This will enable surveyors to make informed discussions about the employability of terrestrial laser scanning without additional control in mid to large-scale projects.

  19. Embedding complementary imaging data in laser scanning microscopy micrographs by reversible watermarking

    PubMed Central

    Dragoi, Ioan-Catalin; Stanciu, Stefan G.; Hristu, Radu; Coanda, Henri-George; Tranca, Denis E.; Popescu, Marius; Coltuc, Dinu

    2016-01-01

    Complementary laser scanning microscopy micrographs are considered as pairs consisting in a master image (MI) and a slave image (SI), the latter with potential for facilitating the interpretation of the MI. We propose a strategy based on reversible watermarking for embedding a lossy compressed version of the SI into the MI. The use of reversible watermarking ensures the exact recovery of the host image. By storing and/or transmitting the watermarked MI in a single file, the information contained in both images that constitute the pair is made available to a potential end-user, which simplifies data association and transfer. Examples are presented using support images collected by two complementary techniques, confocal scanning laser microscopy and transmission laser scanning microscopy, on Hematoxylin and Eosin stained tissue fragments. A strategy for minimizing the watermarking distortions of the MI, while preserving the content of the SI, is discussed in detail. PMID:27446641

  20. Two-versus one photon excitation laser scanning microscopy: Critical importance of excitation wavelength

    PubMed Central

    Bush, Peter G.; Wokosin, David L.; Hall, Andrew C.

    2008-01-01

    It is often anticipated that two-photon excitation (TPE) laser scanning microscopy should improve cell survival and tissue penetration relative to conventional one-photon excitation (OPE) confocal scanning laser microscopy (CLSM). However few studies have directly compared live cell imaging using one- vs two-photon laser scanning microscopy. We have used calcein-loaded in situ chondrocytes within cartilage as a model for quantitatively comparing these techniques. TPE reduced photo-bleaching and improved cell viability compared to OPE. Using improved detection sensitivity coupled with increased tissue penetration of the near infra-red TPE laser, it was possible to capture images deeper within the cartilage. However, the advantages of TPE vs OPE were strongly dependent on excitation wavelength. We conclude that optimising TPE conditions is essential if the full benefits of this approach are to be realised. PMID:17127269

  1. Ultrasonic enrichment of microspheres for ultrasensitive biomedical analysis in confocal laser-scanning fluorescence detection

    NASA Astrophysics Data System (ADS)

    Wiklund, M.; Toivonen, J.; Tirri, M.; Hänninen, P.; Hertz, H. M.

    2004-07-01

    An ultrasonic particle concentrator based on a standing-wave hemispherical resonator is combined with confocal laser-scanning fluorescence detection. The goal is to perform ultrasensitive biomedical analysis by concentration of biologically active microspheres. The standing-wave resonator consists of a 4 MHz focusing ultrasonic transducer combined with the optically transparent plastic bottom of a disposable 96-well microplate platform. The ultrasonic particle concentrator collects suspended microspheres into dense, single-layer aggregates at well-defined positions in the sample vessel of the microplate, and the fluorescence from the aggregates is detected by the confocal laser-scanning system. The biochemical properties of the system are investigated using a microsphere-based human thyroid stimulating hormone assay.

  2. Detection of Gold Nanoparticles Aggregation Growth Induced by Nucleic Acid through Laser Scanning Confocal Microscopy.

    PubMed

    Gary, Ramla; Carbone, Giovani; Petriashvili, Gia; De Santo, Maria Penelope; Barberi, Riccardo

    2016-01-01

    The gold nanoparticle (GNP) aggregation growth induced by deoxyribonucleic acid (DNA) is studied by laser scanning confocal and environmental scanning electron microscopies. As in the investigated case the direct light scattering analysis is not suitable, we observe the behavior of the fluorescence produced by a dye and we detect the aggregation by the shift and the broadening of the fluorescence peak. Results of laser scanning confocal microscopy images and the fluorescence emission spectra from lambda scan mode suggest, in fact, that the intruding of the hydrophobic moiety of the probe within the cationic surfactants bilayer film coating GNPs results in a Förster resonance energy transfer. The environmental scanning electron microscopy images show that DNA molecules act as template to assemble GNPs into three-dimensional structures which are reminiscent of the DNA helix. This study is useful to design better nanobiotechnological devices using GNPs and DNA. PMID:26907286

  3. An Automatic Algorithm for Minimizing Anomalies and Discrepancies in Point Clouds Acquired by Laser Scanning Technique

    NASA Astrophysics Data System (ADS)

    Bordin, Fabiane; Gonzaga, Luiz, Jr.; Galhardo Muller, Fabricio; Veronez, Mauricio Roberto; Scaioni, Marco

    2016-06-01

    Laser scanning technique from airborne and land platforms has been largely used for collecting 3D data in large volumes in the field of geosciences. Furthermore, the laser pulse intensity has been widely exploited to analyze and classify rocks and biomass, and for carbon storage estimation. In general, a laser beam is emitted, collides with targets and only a percentage of emitted beam returns according to intrinsic properties of each target. Also, due interferences and partial collisions, the laser return intensity can be incorrect, introducing serious errors in classification and/or estimation processes. To address this problem and avoid misclassification and estimation errors, we have proposed a new algorithm to correct return intensity for laser scanning sensors. Different case studies have been used to evaluate and validated proposed approach.

  4. Embedding complementary imaging data in laser scanning microscopy micrographs by reversible watermarking.

    PubMed

    Dragoi, Ioan-Catalin; Stanciu, Stefan G; Hristu, Radu; Coanda, Henri-George; Tranca, Denis E; Popescu, Marius; Coltuc, Dinu

    2016-04-01

    Complementary laser scanning microscopy micrographs are considered as pairs consisting in a master image (MI) and a slave image (SI), the latter with potential for facilitating the interpretation of the MI. We propose a strategy based on reversible watermarking for embedding a lossy compressed version of the SI into the MI. The use of reversible watermarking ensures the exact recovery of the host image. By storing and/or transmitting the watermarked MI in a single file, the information contained in both images that constitute the pair is made available to a potential end-user, which simplifies data association and transfer. Examples are presented using support images collected by two complementary techniques, confocal scanning laser microscopy and transmission laser scanning microscopy, on Hematoxylin and Eosin stained tissue fragments. A strategy for minimizing the watermarking distortions of the MI, while preserving the content of the SI, is discussed in detail. PMID:27446641

  5. Embedding complementary imaging data in laser scanning microscopy micrographs by reversible watermarking.

    PubMed

    Dragoi, Ioan-Catalin; Stanciu, Stefan G; Hristu, Radu; Coanda, Henri-George; Tranca, Denis E; Popescu, Marius; Coltuc, Dinu

    2016-04-01

    Complementary laser scanning microscopy micrographs are considered as pairs consisting in a master image (MI) and a slave image (SI), the latter with potential for facilitating the interpretation of the MI. We propose a strategy based on reversible watermarking for embedding a lossy compressed version of the SI into the MI. The use of reversible watermarking ensures the exact recovery of the host image. By storing and/or transmitting the watermarked MI in a single file, the information contained in both images that constitute the pair is made available to a potential end-user, which simplifies data association and transfer. Examples are presented using support images collected by two complementary techniques, confocal scanning laser microscopy and transmission laser scanning microscopy, on Hematoxylin and Eosin stained tissue fragments. A strategy for minimizing the watermarking distortions of the MI, while preserving the content of the SI, is discussed in detail.

  6. Detection of Gold Nanoparticles Aggregation Growth Induced by Nucleic Acid through Laser Scanning Confocal Microscopy

    PubMed Central

    Gary, Ramla; Carbone, Giovani; Petriashvili, Gia; De Santo, Maria Penelope; Barberi, Riccardo

    2016-01-01

    The gold nanoparticle (GNP) aggregation growth induced by deoxyribonucleic acid (DNA) is studied by laser scanning confocal and environmental scanning electron microscopies. As in the investigated case the direct light scattering analysis is not suitable, we observe the behavior of the fluorescence produced by a dye and we detect the aggregation by the shift and the broadening of the fluorescence peak. Results of laser scanning confocal microscopy images and the fluorescence emission spectra from lambda scan mode suggest, in fact, that the intruding of the hydrophobic moiety of the probe within the cationic surfactants bilayer film coating GNPs results in a Förster resonance energy transfer. The environmental scanning electron microscopy images show that DNA molecules act as template to assemble GNPs into three-dimensional structures which are reminiscent of the DNA helix. This study is useful to design better nanobiotechnological devices using GNPs and DNA. PMID:26907286

  7. An automated method to register airborne and terrestrial laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Zang, Yufu; Dong, Zhen; Huang, Ronggang

    2015-11-01

    Laser scanning techniques have been widely used to capture three-dimensional (3D) point clouds of various scenes (e.g. urban scenes). In particular, airborne laser scanning (ALS) and mobile laser scanning (MLS), terrestrial laser scanning (TLS) are effective to capture point clouds from top or side view. Registering the complimentary point clouds captured by ALS and MLS/TLS provides an aligned data source for many purposes (e.g. 3D reconstruction). Among these MLS can be directly geo-referenced to ALS according to the equipped position systems. For small scanning areas or dense building areas, TLS is used instead of MLS. However, registering ALS and TLS datasets suffers from poor automation and robustness because of few overlapping areas and sparse corresponding geometric features. A robust method for the registration of TLS and ALS datasets is proposed, which has four key steps. (1) extracts building outlines from TLS and ALS data sets independently; (2) obtains the potential matching pairs of outlines according to the geometric constraints between building outlines; (3) constructs the Laplacian matrices of the extracted building outlines to model the topology between the geometric features; (4) calculates the correlation coefficients of the extracted geometric features by decomposing the Laplacian matrices into the spectral space, providing correspondences between the extracted features for coarse registration. Finally, the multi-line adjustment strategy is employed for the fine registration. The robustness and accuracy of the proposed method are verified using field data, demonstrating a reliable and stable solution to accurately register ALS and TLS datasets.

  8. SAR Satellite Images and Terrestrial Laser Scanning in Forest Damages Mapping in Finland

    NASA Astrophysics Data System (ADS)

    Karjalainen, Mika; Kaasalainen, Sanna; Hyyppa, Juha; Holopainen, Markus; Lyytikainen-Saarenmaa, Paivi; Krooks, Anssi; Jaakkola, Anttoni

    2010-12-01

    Forests are of high importance for the Finnish economy and environment. Forests inventories should not only provide information about the volume of growing stock, but also about the health status of forests, which is an indicator of the annual growth of forests and Carbon balance. One of the forest damage types is defoliation, which causes forest growth reduction and consequently potentially economical losses to the forest owners, but can be seen as an environmental indicator also. For example, in the past ten years, extensive and persistent needle defoliation caused by insects has been observed in the areas of Palokangas and Outokumpu in Eastern Finland. It is expected that the insect outbreaks are becoming more common and new species of insects may be spreading out in Finland due to the climate warming. Traditionally the intensity of needle defoliation has been estimated using visual observations, which are prone to errors and their areal extent is limited. Therefore, remote sensing can be seen as a potential tool for mapping defoliation. In this study, both Terrestrial Laser Scanning data and SAR satellite images have been exploited. On the one hand, Terrestrial Laser Scanning provides means to rapidly and objectively measure critical forest related information. On the other hand, SAR satellite images enable wide-area mapping and constant monitoring, which would be impossible in Finland using optical satellite images due to the cloudiness. The fusion of Laser scanning and SAR information could make a difference in forest health mapping. In this paper, preliminary results of the estimation of the needle defoliation intensity based on Terrestrial Laser Scanning and ERS and Envisat SAR (non-interferometric) satellite data are presented.

  9. UNDERSTANDING THE EFFECTS OF SURFACTANT ADDITION ON RHEOLOGY USING LASER SCANNING CONFOCAL MICROSCOPY

    SciTech Connect

    White, T

    2007-05-08

    The effectiveness of three dispersants to modify rheology was examined using rheology measurements and laser scanning confocal microscopy (LSCM) in simulated waste solutions. All of the dispersants lowered the yield stress of the slurries below the baseline samples. The rheology curves were fitted reasonably to a Bingham Plastic model. The three-dimensional LSCM images of simulants showed distinct aggregates were greatly reduced after the addition of dispersants leading to a lowering of the yield stress of the simulated waste slurry solutions.

  10. The application study on laser scanning tridimensional modeling of human body

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Guo, Ling; Li, Yuxiang; Yao, Jianquan; Ma, Guilan

    2009-11-01

    A novel three-dimensional human body modeling method on laser technology, using the CCD camera to receive the scanning information, based on the theory of aerial photography surveying and 36 characteristic measuring points, is reported here. We introduce the mode integration of human body and the principle of human body feature identifying. The laser scanning human body three-dimensional modeling system is established.

  11. Atomic force microscopy and confocal laser scanning microscopy on the cytoskeleton of permeabilised and embedded cells.

    PubMed

    Meller, Karl; Theiss, Carsten

    2006-03-01

    We describe a technical method of cell permeabilisation and embedding to study the organisation and distribution of intracellular proteins with aid of atomic force microscopy and confocal laser scanning microscopy in identical areas. While confocal laser scanning microscopy is useful for the identification of certain proteins subsequent labelling with markers or antibodies, atomic force microscopy allows the observation of macromolecular structures in fixed and living cells. To demonstrate the field of application of this preparatory technique, cells were permeabilised, fixed, and the actin cytoskeleton was stained with phalloidin-rhodamine. Confocal laser scanning microscopy was used to show the organisation of these microfilaments, e.g. geodesic dome structures. Thereafter, cells were embedded in Durcupan water-soluble resin, followed by UV-polymerisation of resin at 4 degrees C. This procedure allowed intracellular visualisation of the cell nucleus or cytoskeletal elements by atomic force microscopy, for instance to analyse the globular organisation of actin filaments. Therefore, this method offers a great potential to combine both microscopy techniques in order to understand and interpret intracellular protein relations, for example, the biochemical and morphological interaction of the cytoskeleton. PMID:16360280

  12. 3D laser scanning and modelling of the Dhow heritage for the Qatar National Museum

    NASA Astrophysics Data System (ADS)

    Wetherelt, A.; Cooper, J. P.; Zazzaro, C.

    2014-08-01

    Curating boats can be difficult. They are complex structures, often demanding to conserve whether in or out of the water; they are usually large, difficult to move on land, and demanding of gallery space. Communicating life on board to a visiting public in the terra firma context of a museum can be difficult. Boats in their native environment are inherently dynamic artifacts. In a museum they can be static and divorced from the maritime context that might inspire engagement. New technologies offer new approaches to these problems. 3D laser scanning and digital modeling offers museums a multifaceted means of recording, monitoring, studying and communicating watercraft in their care. In this paper we describe the application of 3D laser scanning and subsequent digital modeling. Laser scans were further developed using computer-generated imagery (CGI) modeling techniques to produce photorealistic 3D digital models for development into interactive, media-based museum displays. The scans were also used to generate 2D naval lines and orthographic drawings as a lasting curatorial record of the dhows held by the National Museum of Qatar.

  13. Multiparameter Correction Intensity of Terrestrial Laser Scanning Data as AN Input for Rock Surface Modelling

    NASA Astrophysics Data System (ADS)

    Paleček, V.; Kubíček, P.

    2016-06-01

    A large increase in the creation of 3D models of objects all around us can be observed in the last few years; thanks to the help of the rapid development of new advanced technologies for spatial data collection and robust software tools. A new commercially available airborne laser scanning data in Czech Republic, provided in the form of the Digital terrain model of the fifth generation as irregularly spaced points, enable locating the majority of rock formations. However, the positional and height accuracy of this type of landforms can reach huge errors in some cases. Therefore, it is necessary to start mapping using terrestrial laser scanning with the possibility of adding a point cloud data derived from ground or aerial photogrammetry. Intensity correction and noise removal is usually based on the distance between measured objects and the laser scanner, the incidence angle of the beam or on the radiometric and topographic characteristics of measured objects. This contribution represents the major undesirable effects that affect the quality of acquisition and processing of laser scanning data. Likewise there is introduced solutions to some of these problems.

  14. Terrestrial laser scanning to model sunlight irradiance on cadavers under conditions of natural decomposition.

    PubMed

    Bucheli, Sibyl Rae; Pan, Zhigang; Glennie, Craig L; Lynne, Aaron M; Haarman, Daniel P; Hill, John M

    2014-07-01

    Human decomposition is a dynamic process that is influenced by both abiotic and biotic factors. Measuring these influences, in particular abiotic factors, on the decomposition process is often a challenge for scientists. Recently, researchers have turned to the use of advanced remote sensing technologies in forensic investigations. In this study, a new methodology is described that utilizes precise 3D images captured using terrestrial laser scanning (TLS) to calculate total solar irradiance on a cadaver in a partially forested environment. To test this new measurement approach under actual field conditions, three cadavers were placed in an outdoor environment to decompose. Laser scans were taken the day of placement and used to calculate the total solar irradiance at time points of 24 h, 1 week, and 1 month from placement. The results show that as time progresses, different cadavers at the field site and different areas of the same cadaver receive varying amounts of solar irradiance. The modeling based on these laser scans can be used to create predictive images of solar irradiance that may provide researchers with a new tool to help quantitatively assess the effect of solar irradiance on a cadaver ecosystem.

  15. 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.

  16. Roof Modelling Potential of Unmanned Air Vehicle Point Clouds with Respect to Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Karakis, Serkan; Gunes Sefercik, Umut; Atalay, Can

    2016-07-01

    In parallel with the improvement of laser scanning technologies, dense point clouds which provide the detailed description of terrain and non-terrain objects became indispensable for remotely-sensed data users. Owing to the large demand, besides laser scanning, point clouds were started to achieve using photogrammetric images. Unmanned air vehicle (UAV) images are one of the most preferred data for creating dense point clouds by the advantage of low cost, rapid and periodically gain. In this study, we tried to assess the roof modelling potential of UAV point clouds by comparing three dimensional (3D) roof models produced from UAV and terrestrial laser scanning (TLS) point clouds. In the study, very popular low cost action camera SJ4000 and Faro Laser Scanner Focus3D X 330 were used to provide point clouds and the roof of Bulent Ecevit University Civil Aviation Academy building was utilized. For the validation of horizontal and vertical geolocation accuracies, standard deviation was used as the main indicator. The visual results demonstrated that UAV roof model is almost coherent with TLS roof model after the filtering-based refinement on noisy pixels and systematic bias correction. Moreover, the horizontal geolocation accuracy is approx. |5cm| both in X and Y directions and bias corrected vertical geolocation accuracy is approx. 17cm for zero roof slope.

  17. Terrestrial Laser Scanning for Measuring Stream Bank Erosion within Legacy Sediments: Data Processing and Analysis Methods

    NASA Astrophysics Data System (ADS)

    Starek, M. J.; Mitasova, H.; Wegmann, K. W.

    2011-12-01

    Land clearing for agricultural purposes following European settlement of America resulted in upland erosion rates 50-400 times above long-term geologic rates in much of the North Carolina Piedmont region. A considerable amount of the eroded sediment was subsequently aggraded on floodplains and impounded in the slackwater ponds behind milldams. This trapped "legacy" sediment is commonly mistaken for natural floodplain deposition and has remained largely unrecognized as a potential source of accelerated sediment erosion contributing to modern water quality impairment. In this study, terrestrial laser scanning (TLS) is utilized to monitor stream bank evolution along a reach that has breached a former millpond. Due to the unique surface geometry and orientation of the stream bank, vegetation occlusion, and true 3D structure of the point cloud, a systematic data processing approach is implemented to compute the change in sediment volume between repeat TLS surveys. The processing approach consists of the following four steps: 1) segmentation of the stream bank point cloud; 2) transformation of the point cloud such that the xy plane is parallel to the trend of the bank; 3) filter vegetation by selecting local lowest point within a grid cell; 4) smooth high frequency noise 5) generate bare earth digital elevation model (DEM). From the DEMs, change in volume was quantified for a 13 m x 3.5 m section of the stream bank providing an estimate on erosion rates and slumping between surveys. The major mechanisms for the observed changes are freeze-thaw events and fluvial entrainment. To evaluate the surface evolution between the distinct sedimentary layers (legacy vs non-legacy) that comprise the stream bank, elevation change is modeled as a continuous trivariate function z = f(x,y,t) where x,y is horizontal location, t is time, and z is a first-surface referenced elevation. Hence, z=0 for all x,y at t=0, time of first survey. The filtered, transformed, and first

  18. Laser scanning methods and a phase comparison, modulated laser range finder for terrain sensing on a Mars roving vehicle. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Herb, G. T.

    1973-01-01

    Two areas of a laser range finder for a Mars roving vehicle are investigated: (1) laser scanning systems, and (2) range finder methods and implementation. Several ways of rapidly scanning a laser are studied. Two digital deflectors and a matrix of laser diodes, are found to be acceptable. A complete range finder scanning system of high accuracy is proposed. The problem of incident laser spot distortion on the terrain is discussed. The instrumentation for a phase comparison, modulated laser range finder is developed and sections of it are tested.

  19. Combining laser scan and photogrammetry for 3D object modeling using a single digital camera

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Zhang, Hong; Zhang, Xiangwei

    2009-07-01

    In the fields of industrial design, artistic design and heritage conservation, physical objects are usually digitalized by reverse engineering through some 3D scanning methods. Laser scan and photogrammetry are two main methods to be used. For laser scan, a video camera and a laser source are necessary, and for photogrammetry, a digital still camera with high resolution pixels is indispensable. In some 3D modeling tasks, two methods are often integrated to get satisfactory results. Although many research works have been done on how to combine the results of the two methods, no work has been reported to design an integrated device at low cost. In this paper, a new 3D scan system combining laser scan and photogrammetry using a single consumer digital camera is proposed. Nowadays there are many consumer digital cameras, such as Canon EOS 5D Mark II, they usually have features of more than 10M pixels still photo recording and full 1080p HD movie recording, so a integrated scan system can be designed using such a camera. A square plate glued with coded marks is used to place the 3d objects, and two straight wood rulers also glued with coded marks can be laid on the plate freely. In the photogrammetry module, the coded marks on the plate make up a world coordinate and can be used as control network to calibrate the camera, and the planes of two rulers can also be determined. The feature points of the object and the rough volume representation from the silhouettes can be obtained in this module. In the laser scan module, a hand-held line laser is used to scan the object, and the two straight rulers are used as reference planes to determine the position of the laser. The laser scan results in dense points cloud which can be aligned together automatically through calibrated camera parameters. The final complete digital model is obtained through a new a patchwise energy functional method by fusion of the feature points, rough volume and the dense points cloud. The design

  20. Terrestrial laser scanning for high resolution cyclostratigraphy of chert in pelagic limestone series

    NASA Astrophysics Data System (ADS)

    Penasa, L.; Franceschi, M.; Preto, N.

    2012-04-01

    We here propose the use of terrestrial laser scanning (TLS) for the mapping of chert on natural outcrops and for rapid extraction of its distribution along stratigraphic sections. The technique permits rapid production of high-definition time series for cyclostratigraphic analysis. Chert, sometimes referred to as flint, is a widespread component of sedimentary successions. It is often found in deep water and pelagic sediments and is constituted by cryptocrystalline varieties of quartz. It is generally accepted that the origin of chert is principally biogenic; it derives from the slow alteration, through a process called maturation, of opaline organic components as tests and spicules under the influence of pore waters. Most often, chert forms nodules of various size, or more or less continuous layers. Its color shows strong variability (white, red, gray, black). Although it could record paleoceanographic and climatic changes because of its biogenic nature, the cyclostratigraphic study of chert is largely neglected. This is mainly due to the difficulty of logging it. Hand logging is time consuming, but also, because of nodules' highly variable shape, lateral variability of chert abundance is large. Photographic image-processing techniques could help in principle, but they become difficult to use when chert has a color similar to that of the host rock. Chert is easily detectable in TLS generated images because of its very low reflectivity at infrared (IR) wavelengths, also where the color of chert in visible light is close to that of the host rock. Thus, TLS data can be used to map the distribution of chert on an outcrop, and to compute its abundance along a stratigraphic section. The ultimate result of such data processing, for which a suite of original procedures was implemented, is a stratigraphic log that is suitable for time series analysis. A section in the early Cretaceous Maiolica Formation of Central Italy (Gubbio) was considered as preliminary case study for

  1. Improving peatland erosion rate measurements through the use of terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Grayson, R.; Holden, J.; Jones, R.; Lloyd, A.

    2013-12-01

    Globally peatlands account for 30-50% of all carbon stored within soils (Holden, 2005). Within the UK they represent the single largest terrestrial carbon store, with blanket bogs covering roughly 7.5% (Tallis et al., 1997); unfortunately these upland blanket bogs are often found in a degraded state. The amount of carbon being lost to erosional processes in peatlands is poorly constrained, with estimates typically being based on traditional low-tech methods. Erosion pins have been the primary method for measuring erosion rates in peatlands; however their use is prone to error due to the depth of peat and its high water content which allows both horizontal and vertical movement through time. Erosion pins can only realistically be used over a relatively small area and assume erosion remains constant between pins making any upscaling problematic. Therefore, innovative methods are required to improve estimates of peatland erosion that are capable of increasing both spatial coverage and accuracy. Terrestrial laser scanning is increasingly being used by geomorphologists to produce highly detailed 3D topographic maps. A pilot study was undertaken to assess the ability of terrestrial laser scanning to measure erosion rates within peatlands and to identify any obstacles that may need to be overcome. An actively eroding blanket bog in northern England was chosen as the test site with surveys being carried out before and after winter as active erosion is most likely during winter months. Erosion measurements were also made using erosion pins to allow comparisons between the two methods. Terrestrial laser scanning was not only found to offer vastly improved spatial coverage compared with erosion pins but was also able to provide data at a much higher resolution. Erosion rates calculated using erosion pins were significantly higher than the average rate calculated using terrestrial laser scanning (-35mm compared to +2.5mm), this overestimation by the erosion pins primarily

  2. Extraction of Forest Roads from Full-waveform Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Djuricic, Ana; Hollaus, Markus

    2013-04-01

    The knowledge about the position of forest roads is important for the management and protection of forests. Most often this information is not available on a digital form so that it can be integrated into a GIS to use it e.g. for routing applications or to plan harvesting activities. Furthermore, the available information about forest roads is often not up-to-date. The extraction of forest roads from remote sensing data i.e. aerial photographs is often limited due to the visibility of the terrain within a forest. The increasing availability of airborne laser scanning (ALS) data has changed this situation during the last years. As an active measurement system ALS provide geometric information from the forest floor as well as the forest canopy. Additionally, the new generation of ALS sensors, the so-called full-waveform sensors provide in addition to the geometric information (i.e. 3D position, echo width) radiometric information (i.e. backscatter cross section) about the backscattering objects, which are excellent data sources to describe the terrain surface within a forest. Thus the aim of this study is to develop a semi-automatic method to extract the position of forest roads from full-waveform ALS data. Based on the 3D point cloud different raster layers were derived such as the digital terrain model (DTM), the slope, the backscatter cross section, different roughness parameters (i.e. echo width, standard deviation of plane fitting residuals of terrain points), the vertical component of the surface normals and the normalized digital surface model (nDSM), which represents the object height above the natural ground. The developed workflow classifies each input raster separately into the classes roads and non-roads. Morphological operations were applied on the classified raster datasets to smooth the outline of the extracted roads and to remove any small gaps in the detected roads. Several raster outputs were combined and used further for additional GIS analysis and

  3. Photogrammetry and Laser Scanning for the Earth Sciencesworking Group V6

    NASA Astrophysics Data System (ADS)

    Chandler, J. H.; Buckley, S. J.; Rieke-Zapp, D.; Wackrow, R.

    2012-07-01

    With the UK gaining responsibility for Commission V at the Beijing Congress in 2008, there was an opportunity to create a new working group focusing on earth science applications at close range. The earth science community has had a long tradition of using close range photogrammetry, and more recently laser scanning, and such opportunities have not been fully recognised by ISPRS in the past. Formation of a new ISPRS Working Group helps to bridge this gap and promotes the skills of ISPRS members more widely. The purpose of this paper is to justify the creation of Working Group V6 and identify some of the activities conducted over the last four years. In particular, reference will be made to the various technical sessions which have been organised and supported across the world, the first resulting in a Special Issue of The Photogrammetric Record published in September 2010. In addition, Working Group V6 has been responsible for the creation of two freely available guidance documents entitled "tips for the effective use of digital close range photogrammetry and terrestrial laser scanning". The former focuses on close range digital photogrammetry and has developed through several iterations with input from both academic and industrial users from around the world. For this reason it should be of distinct value to new and perhaps non-expert users interested in using photogrammetry for earth science applications. The paper includes a discussion which considers whether the initial four years of activity have been successful. A superficial assessment based upon the number of members attracted worldwide would suggest that this has indeed been the case. A deeper comparison between proposed activities and those actually achieved suggest some discrepancy, which is perhaps inevitable as Working Group Officers clearly have other responsibilities. However, examination of papers published in the earth surface journals reveal high incidence of photogrammetry and laser scanning

  4. Gravel transport by ice in a subarctic river from accurate laser scanning

    NASA Astrophysics Data System (ADS)

    Lotsari, Eliisa; Wang, Yunsheng; Kaartinen, Harri; Jaakkola, Anttoni; Kukko, Antero; Vaaja, Matti; Hyyppä, Hannu; Hyyppä, Juha; Alho, Petteri

    2015-10-01

    For decades the importance of ice and the effects of cold-region processes on river channel morphology have been discussed, with a general consensus as to their importance emerging only recently. River ice cover, anchor ice, frazil ice, and ice jams may not only scour the channel bed and banks but also pick up, transport, and deposit fine sediments and gravels during winter, especially during the spring ice breakup period. However, knowledge of the interactions between coarse sediment transport and ice processes remains insufficient, particularly in rockier river reaches, with a lack of accurate and sufficiently extensive data hindering their quantification. The aim of this study was to quantify and analyse the impact of river ice on gravel transport in a subarctic river during one winter via the acquisition of laser scanning data for the river channel and ice surface. Terrestrial and mobile laser scanning were performed in 2012-2013 on the Tana River in northern Finland. Both of these techniques are considered accurate and applicable for detecting elevation and volumetric changes in river bed, defining gravel clast sizes, and detecting the movement of individual clasts. More importantly, ice surface, thickness, and decay during spring were also captured via laser scanning. In the winter of 2012-2013, a period characterised by an absence of ice jams and mid-winter ice-decay periods, with spring ice breakup discharges close to average yearly conditions, ice had the most significant role, greater than that of flowing water, in erosion and transport of coarse sediment from the channel bed and gently sloping banks. Changes in river bed elevation and volume were recorded throughout the study site, and erosion predominated. In addition to broader scale erosion, the movement of single clasts up to 2 m in size occurred. However, the observed overall channel change patterns did not coincide with the areas of fastest ice decay. The obtained results could also be applied to

  5. Image distortion and its correction in linear galvanometric mirrors-based laser-scanning microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Wenbo; Wu, Zhenguo; Zeng, Haishan

    2015-05-01

    To simplify imaging focusing and calibration tasks, a laser-scanning microscope needs to scan at a moderate frame rate. The inertia of a galvanometric scanner leads to time delays when following external commands, which subsequently introduces image distortions that deteriorate as scan frequency increases. Sinusoidal and triangular waveforms were examined as fast axis driving patterns. The interplay among driving pattern, frequency, sampling rate, phase shift, linear scanning range, and their effect on reconstructed images was discussed. Utilizing position feedback from the linear galvo scanners, the effect of response time could be automatically compensated in real time. Precompensated triangular driving waveform offered the least amount of image distortion.

  6. A Survey Study of the Blast Furnace at Kuangshan Village Using 3D Laser Scanning

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Huang, Xing; Qian, Wei

    2016-10-01

    The blast furnace from the Northern Song Dynasty at Kuangshan Village is the tallest blast furnace that remains from ancient China. Previous studies have assumed that the furnace had a closed mouth. In this paper, a three-dimensional (3D) model of the blast furnace is constructed using 3D laser scanning technology, and accurate profile data are obtained using software. It is shown that the furnace throat is smaller than had been previously thought and that the furnace mouth is of the open type. This new furnace profile constitutes a discovery in the history of iron-smelting technology.

  7. Low temperature laser scanning microscopy of a superconducting radio-frequency cavity

    DOE PAGESBeta

    Ciovati, G.; Anlage, Steven M.; Baldwin, C.; Cheng, G.; Flood, R.; Jordan, K.; Kneisel, P.; Morrone, M.; Nemes, G.; Turlington, L.; et al

    2012-03-16

    An apparatus was created to obtain, for the first time, 2D maps of the surface resistance of the inner surface of an operating superconducting radio-frequency niobium cavity by a low-temperature laser scanning microscopy technique. This allows identifying non-uniformities of the surface resistance with a spatial resolution of about one order of magnitude better than with earlier methods. A signal-to-noise ratio of about 10 dB was obtained with 240 mW laser power and 1 Hz modulation frequency. The various components of the apparatus, the experimental procedure and results are discussed in details in this contribution.

  8. In vivo measurements of skin barrier: comparison of different methods and advantages of laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Patzelt, A.; Sterry, W.; Lademann, J.

    2010-12-01

    A major function of the skin is to provide a protective barrier at the interface between external environment and the organism. For skin barrier measurement, a multiplicity of methods is available. As standard methods, the determination of the transepidermal water loss (TEWL) as well as the measurement of the stratum corneum hydration, are widely accepted, although they offer some obvious disadvantages such as increased interference liability. Recently, new optical and spectroscopic methods have been introduced to investigate skin barrier properties in vivo. Especially, laser scanning microscopy has been shown to represent an excellent tool to study skin barrier integrity in many areas of relevance such as cosmetology, occupation, diseased skin, and wound healing.

  9. Automatic Geo-Referencing Mobile Laser Scanning Data to Uav Images

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Huang, X.; Zhang, F.; Fu, Z.; Yang, C.

    2015-08-01

    In this paper, a framework for adjusting mobile laser scanning point cloud data to improve the accuracy is proposed by integrating high resolution UAV images and MLS. First, aerial triangulated images with a few high accuracy ground control points are taken as control information. Then, a hierarchical strategy is proposed for robust pairwise registration of feature points between point cloud and images, so as to find the deviation of the point cloud. In the next step, a shape-preserving piecewise cubic interpolating method is employed to fit the time dependent error model of the trajectory. Finally, experiments are given to prove the effectiveness of proposed framework.

  10. Image distortion and its correction in linear galvanometric mirrors-based laser-scanning microscopy.

    PubMed

    Wang, Wenbo; Wu, Zhenguo; Zeng, Haishan

    2015-05-01

    To simplify imaging focusing and calibration tasks, a laser-scanning microscope needs to scan ata moderate frame rate. The inertia of a galvanometric scanner leads to time delays when following external commands, which subsequently introduces image distortions that deteriorate as scan frequency increases. Sinusoidal and triangular waveforms were examined as fast axis driving patterns. The interplay among driving pattern, frequency, sampling rate, phase shift, linear scanning range, and their effect on reconstructed images was discussed. Utilizing position feedback from the linear galvo scanners, the effect of response time could be automatically compensated in real time. Precompensated triangular driving waveform offered the least amount of image distortion.

  11. Alternative Method for Simulating IPSF in Two-Photon Laser Scanning Microscopy

    NASA Astrophysics Data System (ADS)

    Zhou, YongJun; Chen, DeQiang; Huang, Wenhao; Xia, Andong

    2002-09-01

    The refractive-index mismatch induced by coverslips will lead to the distortion of two-photon laser scanning microscopy (TPLSM) images. Such distortion will result in the elongation of the intensity point spread function (IPSF). In order to predict the trend and extent of the distortion, we develop a new data proceeding method which combines Torok"s theory with the experimental value. This method considers the fluorescence quantum efficiency of the sample together with the detection efficiency of the system. By calculating IPSF and using our method to proceed the data, the simulation results are quite consistent with experimental results.

  12. Use of terrestrial laser scanning technology for long term high precision deformation monitoring.

    PubMed

    Vezočnik, Rok; Ambrožič, Tomaž; Sterle, Oskar; Bilban, Gregor; Pfeifer, Norbert; Stopar, Bojan

    2009-01-01

    The paper presents a new methodology for high precision monitoring of deformations with a long term perspective using terrestrial laser scanning technology. In order to solve the problem of a stable reference system and to assure the high quality of possible position changes of point clouds, scanning is integrated with two complementary surveying techniques, i.e., high quality static GNSS positioning and precise tacheometry. The case study object where the proposed methodology was tested is a high pressure underground pipeline situated in an area which is geologically unstable.

  13. Imaging Single ZnO Vertical Nanowire Laser Cavities using UV-Laser Scanning Confocal Microscopy

    SciTech Connect

    Gargas, D.J.; Toimil-Molares, M.E.; Yang, P.

    2008-11-17

    We report the fabrication and optical characterization of individual ZnO vertical nanowire laser cavities. Dilute nanowire arrays with interwire spacing>10 ?m were produced by a modified chemical vapor transport (CVT) method yielding an ideal platform for single nanowire imaging and spectroscopy. Lasing characteristics of a single vertical nanowire are presented, as well as high-resolution photoluminescence imaging by UV-laser scanning confocal microscopy. In addition, three-dimensional (3D) mapping of the photoluminescence emission performed in both planar and vertical dimensions demonstrates height-selective imaging useful for vertical nanowires and heteronanostructures emerging in the field of optoelectronics and nanophotonics.

  14. Terrestrial Laser Scanning Cultural Heritage preservation in case of natural hazards

    NASA Astrophysics Data System (ADS)

    Kordic, B.; Medak, D.; Pribicevic, B.

    2009-04-01

    Croatian Adriatic coast and the City of Zagreb area are hazardous with respect to earthquake occurance. These areas are rich with cultural monuments, buildings, sculptures... Accurate 3D documentation is needed for reconstruction in case of damage caused by natural disasters like earthquake, landslide ,fire... The technology of terestrial laser scanning is a promising method for providing exact 3D models of cultural heritage. Meshes, point-clouds and models should be collected and constructed. Georeferenced models can be used for tourism as a basis for virtual worlds available both in the WWW or on DVD-s...

  15. Voxel-Based Approach for Estimating Urban Tree Volume from Terrestrial Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Vonderach, C.; Voegtle, T.; Adler, P.

    2012-07-01

    The importance of single trees and the determination of related parameters has been recognized in recent years, e.g. for forest inventories or management. For urban areas an increasing interest in the data acquisition of trees can be observed concerning aspects like urban climate, CO2 balance, and environmental protection. Urban trees differ significantly from natural systems with regard to the site conditions (e.g. technogenic soils, contaminants, lower groundwater level, regular disturbance), climate (increased temperature, reduced humidity) and species composition and arrangement (habitus and health status) and therefore allometric relations cannot be transferred from natural sites to urban areas. To overcome this problem an extended approach was developed for a fast and non-destructive extraction of branch volume, DBH (diameter at breast height) and height of single trees from point clouds of terrestrial laser scanning (TLS). For data acquisition, the trees were scanned with highest scan resolution from several (up to five) positions located around the tree. The resulting point clouds (20 to 60 million points) are analysed with an algorithm based on voxel (volume elements) structure, leading to an appropriate data reduction. In a first step, two kinds of noise reduction are carried out: the elimination of isolated voxels as well as voxels with marginal point density. To obtain correct volume estimates, the voxels inside the stem and branches (interior voxels) where voxels contain no laser points must be regarded. For this filling process, an easy and robust approach was developed based on a layer-wise (horizontal layers of the voxel structure) intersection of four orthogonal viewing directions. However, this procedure also generates several erroneous "phantom" voxels, which have to be eliminated. For this purpose the previous approach was extended by a special region growing algorithm. In a final step the volume is determined layer-wise based on the extracted

  16. Semi-automated extraction and delineation of 3D roads of street scene from mobile laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Fang, Lina; Li, Jonathan

    2013-05-01

    Accurate 3D road information is important for applications such as road maintenance and virtual 3D modeling. Mobile laser scanning (MLS) is an efficient technique for capturing dense point clouds that can be used to construct detailed road models for large areas. This paper presents a method for extracting and delineating roads from large-scale MLS point clouds. The proposed method partitions MLS point clouds into a set of consecutive "scanning lines", which each consists of a road cross section. A moving window operator is used to filter out non-ground points line by line, and curb points are detected based on curb patterns. The detected curb points are tracked and refined so that they are both globally consistent and locally similar. To evaluate the validity of the proposed method, experiments were conducted using two types of street-scene point clouds captured by Optech's Lynx Mobile Mapper System. The completeness, correctness, and quality of the extracted roads are over 94.42%, 91.13%, and 91.3%, respectively, which proves the proposed method is a promising solution for extracting 3D roads from MLS point clouds.

  17. Confocal laser scanning microscopic analysis of the depth of dentin caries-like lesions in primary and permanent teeth.

    PubMed

    de Carvalho, Fabíola Galbiatti; de Fucio, Suzana Beatriz Portugal; Sinhoreti, Mario Alexandre Coelho; Correr-Sobrinho, Lourenço; Puppin-Rontani, Regina Maria

    2008-01-01

    This study analyzed comparatively, by confocal laser scanning microscopy (CLSM), the depth of caries-like lesions produced by biological and chemical artificial models in permanent and primary dentin. Six primary molars and six premolars were used. The occlusal enamel was removed and a nail polish layer was applied on the specimens, except for a 4 x 2 mm area on dentin surface. Half of specimens were immersed in acid gel for 14 days (chemical model) and the other half was immersed in BHI broth with S. mutans for 14 days (biological model). After development of artificial caries, the crowns were longitudinally sectioned on the center of the carious lesion. Three measurements of carious dentin depth were made in each specimen by CLSM. Measurements depths were compared between the caries models and between tooth types by one-way ANOVA and Tukey test (alpha=5%). For permanent teeth, the biological model showed significantly higher (p<0.05) caries depth values than the chemical model. For primary teeth, no statistically significant difference (p>0.05) was found between the caries models. The artificial caries model influenced caries depth only in permanent teeth. There was no difference in carious dentin depth between permanent and primary teeth, regardless of the artificial caries model. PMID:18568229

  18. Imaging and Mapping of Tissue Constituents at the Single-Cell Level Using MALDI MSI and Quantitative Laser Scanning Cytometry.

    PubMed

    Rawlins, Catherine M; Salisbury, Joseph P; Feldman, Daniel R; Isim, Sinan; Agar, Nathalie Y R; Luther, Ed; Agar, Jeffery N

    2015-01-01

    For nearly a century, histopathology involved the laborious morphological analyses of tissues stained with broad-spectrum dyes (i.e., eosin to label proteins). With the advent of antibody-labeling, immunostaining (fluorescein and rhodamine for fluorescent labeling) and immunohistochemistry (DAB and hematoxylin), it became possible to identify specific immunological targets in cells and tissue preparations. Technical advances, including the development of monoclonal antibody technology, led to an ever-increasing palate of dyes, both fluorescent and chromatic. This provides an incredibly rich menu of molecular entities that can be visualized and quantified in cells-giving rise to the new discipline of Molecular Pathology. We describe the evolution of two analytical techniques, cytometry and mass spectrometry, which complement histopathological visual analysis by providing automated, cellular-resolution constituent maps. For the first time, laser scanning cytometry (LSC) and matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) are combined for the analysis of tissue sections. The utility of the marriage of these techniques is demonstrated by analyzing mouse brains with neuron-specific, genetically encoded, fluorescent proteins. We present a workflow that: (1) can be used with or without expensive matrix deposition methods, (2) uses LSC images to reveal the diverse landscape of neural tissue as well as the matrix, and (3) uses a tissue fixation method compatible with a DNA stain. The proposed workflow can be adapted for a variety of sample preparation and matrix deposition methods. PMID:26542720

  19. 3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes

    SciTech Connect

    Fredrich, J.T.

    1999-02-10

    We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and axial planes. The resultant volumetric image data, consisting of fluorescence intensities for typically {approximately}50 million voxels in XYZ space, can be used to reconstruct the three-dimensional structure of the two-phase medium. We present several examples of this application, including studying pore geometry in sandstone, characterizing brittle failure processes in low-porosity rock deformed under triaxial loading conditions in the laboratory, and analyzing the microstructure of porous ceramic insulations. We then describe approaches to extract statistical microgeometric descriptions from volumetric image data, and present results derived from confocal volumetric data sets. Finally, we develop the use of confocal image data to automatically generate a three-dimensional mesh for numerical pore-scale flow simulations.

  20. Effectiveness of blast-mitigation for rock fall endangered critical infrastructure using terrestrial laser scanning (LIDAR).

    NASA Astrophysics Data System (ADS)

    Kos, A.; Lunghi, A.; Naenni, C.; Conforti, D.; Tompkinson, W.

    2009-04-01

    Following a national rock fall risk assessment undertaken by the Swiss Federal Roads Office (FEDRO) a potential rock fall area located above the San Bernardino highway (A13) at Brusei, Canton Graubünden was identified. The rockslope at Brusei was characterized by a previous record of rock fall, large overhanging outcrops and open tension cracks up to 2 metres. Combined with the fact that the A13 is a critical north-south traffic corridor in Switzerland and the geological situation, the Public Works Department of the Canton Graubünden made the decision to mitigate the rock fall risk with the use of explosives. We report on the use of terrestrial laser scanning for evaluating the effectiveness of mitigation using explosives for the protection of critical infrastructure. Although modern blast mitigation methods allow for accurate control on removed volumes of rock, it is important to calculate how much was actually removed particularly when protection structures, such as rock fall galleries are located in the transit/deposition zone of the blasted area. High resolution laser scanning is an appropriate technology for monitoring the pre- and post blast situation and provides the basis for: 1) Geological investigations for understanding the initial cause of instabilities; 2) Monitoring the formation of potential new instabilities following blast mitigation; and 3) Integration with other spatial monitoring technologies, such as ground-based radar interferometry.

  1. Benchmarking the Performance of Mobile Laser Scanning Systems Using a Permanent Test Field

    PubMed Central

    Kaartinen, Harri; Hyyppä, Juha; Kukko, Antero; Jaakkola, Anttoni; Hyyppä, Hannu

    2012-01-01

    The performance of various mobile laser scanning systems was tested on an established urban test field. The test was connected to the European Spatial Data Research (EuroSDR) project “Mobile Mapping—Road Environment Mapping Using Mobile Laser Scanning”. Several commercial and research systems collected laser point cloud data on the same test field. The system comparisons focused on planimetric and elevation errors using a filtered digital elevation model, poles, and building corners as the reference objects. The results revealed the high quality of the point clouds generated by all of the tested systems under good GNSS conditions. With all professional systems properly calibrated, the elevation accuracy was better than 3.5 cm up to a range of 35 m. The best system achieved a planimetric accuracy of 2.5 cm over a range of 45 m. The planimetric errors increased as a function of range, but moderately so if the system was properly calibrated. The main focus on mobile laser scanning development in the near future should be on the improvement of the trajectory solution, especially under non-ideal conditions, using both improvements in hardware and software. Test fields are relatively easy to implement in built environments and they are feasible for verifying and comparing the performance of different systems and also for improving system calibration to achieve optimum quality.

  2. Application of laser scan microscopy in vivo for wound healing characterization

    NASA Astrophysics Data System (ADS)

    Czaika, V.; Alborova, A.; Sterry, W.; Lademann, J.; Koch, S.

    2010-09-01

    Considering the advancing age of the population, wound healing disturbances are becoming increasingly important in clinical routine. The development of wound healing creams and lotions as well as therapy control require an objective evaluation of the wound healing process, which represents the destruction of the barrier. Therefore, transepidermal water loss measurements are often carried out. These measurements have the disadvantage that they are disturbed by the interstitial fluid, which is located on the surface of chronic wounds and also by water components of the creams and lotions. Additionally, the TEWL measurements are very sensitive to temperature changes and to the anxiety of the volunteers. In the present study, in vivo laser scanning microscopy was used to analyze the reepithelialization and barrier recovery of standardized wounds produced by the suction blister technique. It was demonstrated that this non-invasive, on-line spectroscopic method allows the evaluation of the wound healing process, without any disturbances. It was found that the wound healing starts not only from the edges of the wound, but also out of the hair follicles. The in vivo laser scanning microscopy is well suited to evaluate the efficacy of wound healing creams and for therapy control.

  3. 3-D ice shape measurements using mid-infrared laser scanning.

    PubMed

    Gong, Xiaoliang; Bansmer, Stephan

    2015-02-23

    A general approach based on mid-infrared (MIR) laser scanning is proposed to measure the 3-D ice shape no matter whether the ice is composed of clear ice, rime ice, mixed ice, or even supercooled water droplets or films. This is possible because MIR radiation penetrates ice and water only within a depth of less than 10 micrometers. First, an MIR laser point scanning technique is implemented and verified on transparent glass and clear ice. Then, to improve efficiency, an MIR laser line scanning method is developed and validated on different models. At last, several sequential MIR laser line scans are applied to trace the 3-D shape evolution of the continuous ice accretion on an airfoil in an icing wind tunnel. The ice growth process can be well observed in the results. The MIR scan shows a good agreement with the traditional visible laser scan on a plastic replication of the final ice shape made by the mold and casting method. PMID:25836526

  4. Multispectral airborne laser scanning - a new trend in the development of LiDAR technology

    NASA Astrophysics Data System (ADS)

    Bakuła, K.

    2015-12-01

    Airborne laser scanning (ALS) is the one of the most accurate remote sensing techniques for data acquisition where the terrain and its coverage is concerned. Modern scanners have been able to scan in two or more channels (frequencies of the laser) recently. This gives the rise to the possibility of obtaining diverse information about an area with the different spectral properties of objects. The paper presents an example of a multispectral ALS system - Titan by Optech - with the possibility of data including the analysis of digital elevation models accuracy and data density. As a result of the study, the high relative accuracy of LiDAR acquisition in three spectral bands was proven. The mean differences between digital terrain models (DTMs) were less than 0.03 m. The data density analysis showed the influence of the laser wavelength. The points clouds that were tested had average densities of 25, 23 and 20 points per square metre respectively for green (G), near-infrared (NIR) and shortwave-infrared (SWIR) lasers. In this paper, the possibility of the generation of colour composites using orthoimages of laser intensity reflectance and its classification capabilities using data from airborne multispectral laser scanning for land cover mapping are also discussed and compared with conventional photogrammetric techniques.

  5. Laser Scanning of a Monolithic Column during Processing in Middle Egypt

    NASA Astrophysics Data System (ADS)

    Ajioka, O.; Hori, Y.

    2011-09-01

    From ancient quarries around Akoris in Middle Egypt, which belong to the Ptolemaic and Roman periods, the stone blocks could be carried to the working area located in the outside of the city. Those blocks included a giant monolithic column measured approximately 14m in length, which had been cracked for reasons unknown and must have contributed to disuse of monolith. The first deal is a comparison of plans drawn by the point clouds by laser scanning with those coming from plane-tabling, which had been one of popular methods for measuring in the last century. This part shows how the laser scanning technology is useful in far better measuring and documentation of the site. The second discuss is about a detailed assessment of the procedure of processing through the observation of chisel marks and the detail analysis about the 3 dimensional data. In the result, we are succeed to show the restoration of the procedure of the proceedings using guidelines and a wooden curve since we concentrate attention on the point of abstracting the centre line and shaving the surface into the round shape.

  6. D Documentation of a Historical Monument Using Terrestrial Laser Scanning Case Study: Byzantine Water Cistern, Istanbul

    NASA Astrophysics Data System (ADS)

    Temizer, T.; Nemli, G.; Ekizce, E.; Ekizce, A.; Demir, S.; Bayram, B.; Askin, F. H.; Cobanoglu, A. V.; Yilmaz, H. F.

    2013-07-01

    3D modelling of architectural structures for monitoring, conservation and restoration alterations in heritage sites has special challenges for data acquisition and processing. The accuracy of created 3D model is very important. In general, because of the complexity of the structures, 3D modelling can be time consuming and may include some difficulties. 3D terrestrial laser scanning technique is a reliable and advantageous method for reconstruction and conservation of monuments. This technique is commonly acknowledged due to its accuracy, speed and flexibility. Terrestrial laser scanners can be used for documentation of the cultural heritage for the future. But it is also important to understand the capabilities and right conditions of use and limitations of this technology. Istanbul is a rich city with cultural monuments, buildings and cultural heritage. The presented study consists of documentation of a Byzantine water cistern situated underground the court of Sarnicli Han building. The cistern which represents a very good living example of its period has been modelled in 3D by using terrestrial laser scanning technology and the accuracy assessment of this modelling is examined.

  7. 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

  8. Effects of scanning orientation on outlier formation in 3D laser scanning of reflective surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Yutao; Feng, Hsi-Yung

    2016-06-01

    Inspecting objects with reflective surfaces using 3D laser scanning is a demanded but challenging part inspection task due to undesirable specular reflections, which produce extensive outliers in the scanned point cloud. These outliers need to be removed in order to alleviate subsequent data processing issues. Many existing automatic outlier removal methods do not detect outliers according to the outlier formation properties. As a result, these methods only offer limited capabilities in removing extensive and complex outliers from scanning objects with reflective surfaces. This paper reports an empirical study which experimentally investigates the outlier formation characteristics in relation to the scanning orientation of the laser probe. The objective is to characterize the scanning orientation effects on outlier formation in order to facilitate the development of an effective outlier detection and removal method. Such an experimental investigation was hardly done before. It has been found in this work that scanning orientation can directly affect outlier extensity and occurrence in 3D laser scanning. A general guidance on proper scan path planning can then be provided with an aim to reduce the occurrence of outliers. Further, the observed dependency of outlier formation on scanning orientation can be exploited to facilitate effective and automatic outlier detection and removal.

  9. 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

  10. Geomorphometric analysis of cave ceiling channels mapped with 3-D terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Gallay, Michal; Hochmuth, Zdenko; Kaňuk, Ján; Hofierka, Jaroslav

    2016-05-01

    The change of hydrological conditions during the evolution of caves in carbonate rocks often results in a complex subterranean geomorphology, which comprises specific landforms such as ceiling channels, anastomosing half tubes, or speleothems organized vertically in different levels. Studying such complex environments traditionally requires tedious mapping; however, this is being replaced with terrestrial laser scanning technology. Laser scanning overcomes the problem of reaching high ceilings, providing new options to map underground landscapes with unprecedented level of detail and accuracy. The acquired point cloud can be handled conveniently with dedicated software, but applying traditional geomorphometry to analyse the cave surface is limited. This is because geomorphometry has been focused on parameterization and analysis of surficial terrain. The theoretical and methodological concept has been based on two-dimensional (2-D) scalar fields, which are sufficient for most cases of the surficial terrain. The terrain surface is modelled with a bivariate function of altitude (elevation) and represented by a raster digital elevation model. However, the cave is a 3-D entity; therefore, a different approach is required for geomorphometric analysis. In this paper, we demonstrate the benefits of high-resolution cave mapping and 3-D modelling to better understand the palaeohydrography of the Domica cave in Slovakia. This methodological approach adopted traditional geomorphometric methods in a unique manner and also new methods used in 3-D computer graphics, which can be applied to study other 3-D geomorphological forms.

  11. Measuring calcium levels in Saprolegnia ferax using the two-photon laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Lilje, Osu

    2003-07-01

    xThe genus Saprolegnia in the phylum Oomycetes contains a number of parasitic species that can cause a range of important animal diseases. The aim of this study was to measure the calcium gradient, one of the growth regulating mechanisms, in Saprolegnia ferax. The two-photon laser scanning microscope allowed for detailed physiological measurements of calcium levels along the fungus-like hyphae of S.ferax. Calcium concentration was determined by making ratiometric calculation of emission levels of the calcium-sensitive fluorochrome Indo-1 at 485nm to 405nm. The calculated values were compared to the intracellular calibration values. The advantage of the two-photon laser scanning microscope is that it allows minor changes in concentration to be detected in highly localized regions of the hyphae. The technique used in this study minimized background and autofluorescence and therefore allowed for more accurate changes in intracellular Ca2+ concentration to be detected. The calcium concentration at the hyphal tip and 5, 10 and 40μm distal to the tip were calculated to be 65, 17, 38 and 20nM respectively, confirming other studies that suggest a tip-high calcium gradient.

  12. Observation of dendritic cell morphology under light, phase-contrast or confocal laser scanning microscopy.

    PubMed

    Tan, Yuen-Fen; Leong, Chooi-Fun; Cheong, Soon-Keng

    2010-12-01

    Dendritic cells (DCs) are professional antigen presenting cells of the immune system. They can be generated in vitro from peripheral blood monocytes supplemented with GM-CSF, IL-4 and TNF alpha. During induction, DCs will increase in size and acquire multiple cytoplasmic projections when compared to their precursor cells such as monocytes or haematopoietic stem cells which are usually round or spherical. Morphology of DCs can be visualized by conventional light microscopy after staining or phase-contrast inverted microscopy or confocal laser scanning microscopy. In this report, we described the morphological appearances of DCs captured using the above-mentioned techniques. We found that confocal laser scanning microscopy yielded DCs images with greater details but the operating cost for such a technique is high. On the other hand, the images obtained through light microscopy after appropriate staining or phase contrast microscopy were acceptable for identification purpose. Besides, these equipments are readily available in most laboratories and the cost of operation is affordable. Nevertheless, morphological identification is just one of the methods to characterise DCs. Other methods such as phenotypic expression markers and mixed leukocyte reactions are additional tools used in the characterisation of DCs. PMID:21329180

  13. 3-D ice shape measurements using mid-infrared laser scanning.

    PubMed

    Gong, Xiaoliang; Bansmer, Stephan

    2015-02-23

    A general approach based on mid-infrared (MIR) laser scanning is proposed to measure the 3-D ice shape no matter whether the ice is composed of clear ice, rime ice, mixed ice, or even supercooled water droplets or films. This is possible because MIR radiation penetrates ice and water only within a depth of less than 10 micrometers. First, an MIR laser point scanning technique is implemented and verified on transparent glass and clear ice. Then, to improve efficiency, an MIR laser line scanning method is developed and validated on different models. At last, several sequential MIR laser line scans are applied to trace the 3-D shape evolution of the continuous ice accretion on an airfoil in an icing wind tunnel. The ice growth process can be well observed in the results. The MIR scan shows a good agreement with the traditional visible laser scan on a plastic replication of the final ice shape made by the mold and casting method.

  14. Integrating terrestrial laser scanning and repeat field measurements to quantify habitat changes during baseflow recession

    NASA Astrophysics Data System (ADS)

    Woelfle-Erskine, C. A.; Thompson, S. E.

    2013-12-01

    Understanding stream habitat heterogeneity is essential for evaluating stream habitat quality for salmonids, but the variability in pool sizes, groundwater sources, and the associated water quality makes characterization of habitat challenging. Habitat volume and stream connectivity are key drivers of ecosystem processes in spatially-intermittent streams, and strongly influence survival of juvenile salmonids in coastal California. Stream disconnection creates heterogeneous habitats, as disconnected pools are fed by distinct groundwater and hyporheic sources of water containing different concentrations of carbon, oxygen and nutrients. These distinct biogeochemical regimes drive production of benthic macroinvertebrates (salmonids' primary food source) and dissolved oxygen levels, which in turn govern salmonid metabolism. In this study, we use terrestrial laser scans of the streambed, topographic surveys of wetted pools, and repeat field measurements of pool depth to develop a timeseries of finely resolved pool volumes and dry riffle lengths. We overlay repeat water quality measurements onto this surface to visualize how cessation of flow creates heterogeneous habitats influenced by groundwater flux and geomorphic setting. By coupling terrestrial laser scans with traditional surveys, we create high-resolution facies surfaces that can be integrated with timeseries measurements of other biogeochemical data to characterize changes in habitat conditions during baseflow recession. Compared with traditional survey methods, this method yields improved qualitative descriptions of habitat fragmentation via visualizations and spatially and temporally explicit quantification of aquatic and riparian habitat characteristics that drive salmonid over-summer survival.

  15. Laser Scanning In Vivo Confocal Microscopy of Clear Grafts after Penetrating Keratoplasty

    PubMed Central

    Wang, Dai; Song, Peng; Wang, Shuting; Sun, Dapeng; Wang, Yuexin; Zhang, Yangyang

    2016-01-01

    Purpose. To evaluate the changes of keratocytes and dendritic cells in the central clear graft by laser scanning in vivo confocal microscopy after penetrating keratoplasty (PK). Methods. Thirty adult subjects receiving PK at Shandong Eye Institute and with clear grafts and no sign of immune rejection after surgery were recruited into this study, and 10 healthy adults were controls. The keratocytes and dendritic cells in the central graft were evaluated by laser scanning confocal microscopy, as well as epithelium cells, keratocytes, corneal endothelium cells, and corneal nerves (especially subepithelial plexus nerves). Results. Median density of subepithelial plexus nerves, keratocyte density in each layer of the stroma, and density of corneal endothelium cells were all lower in clear grafts than in controls. The dendritic cells of five (16.7%) patients were active in Bowman's membrane and stromal membrane of the graft after PK. Conclusions. Activated dendritic cells and Langerhans cells could be detected in some of the clear grafts, which indicated that the subclinical stress of immune reaction took part in the chronic injury of the clear graft after PK, even when there was no clinical rejection episode. PMID:27034940

  16. Tissomics: two- and three-dimensional distribution of nuclei in brain tissue using laser scanning cytometry (LSC)

    NASA Astrophysics Data System (ADS)

    Lenz, Domnik; Mittag, Anja; Mosch, Birgit; Bocsi, Jozsef; Arendt, Thomas; Tarnok, Attila

    2005-03-01

    Automated quantitative (i.e. stochiometric) analysis of tissues is of eminent importance in the understanding of all interactions between cells in their natural environment. In tissue cytometry a solid trigger is necessary in order to unequivocally differentiate between cellular and non-cellular events. This can be best performed by nuclear staining. Aim of this study was to analyze a brain tissue section by laser scanning cytometry (LSC) in order to depict the threedimensional distribution of nuclei in the tissue. To this end the section was measured in several foci and different nuclei detected in several depths of the tissue were assigned to the respective layer. Frozen sections of formalin-fixed rat or human brain tissue (120μm thickness) were incubated with propidiumiodide (PI) (50μg/ml) and covered on slides. For analysis by the LSC propidiumiodide was used as trigger. After a first analysis focussed on the top of the tissue, the focus was adjusted in 30μm steps deeper into the tissue. Per analysis data of at least 50,000 cells were acquired. After finishing measurements from all depths of the field were merged, i.e. data were combined into a composite data file. With the special features of the LSC it was possible to develop a method depicting the threedimensional distribution of the nuclei in solid tissue sections. LSC can be useful tool for this relatively new field of solid tissue cytometry termed tissomics. After evaluation of methods like this, so far not available data can be analysed for diagnostic purposes. By these studies we intend to demonstrate the power of the LSC for the routine pathological use. This should add up to the bright versatility of applications for the LSC as a cytometric instrument suitable for high throughput and high content analysis.

  17. Prognostic significance of S-phase fractions in peritumoral invading zone analyzed by laser scanning cytometry in patients with high-grade glioma: A preliminary study

    PubMed Central

    NAKAJIMA, SYOICHI; MORII, KEN; TAKAHASHI, HITOSHI; FUJII, YUKIHIKO; YAMANAKA, RYUYA

    2016-01-01

    The predominant characteristic of malignant glioma is the presence of invading tumor cells in the peritumoral zone. Distinguishing between tumor cells and normal cells in a peritumoral lesion is challenging. Therefore, the aim of the present study was to investigate the cell-cycle phase measurements of fixed paraffin-embedded specimens from the peritumoral invading zone of high-grade gliomas using laser scanning cytometry. A total of 12 high-grade gliomas (2 anaplastic astrocytomas and 10 glioblastomas) were studied. The tumor core and peritumoral invading zone of each tumor specimen were investigated. Tissue sections (50 µm) from the paraffin blocks were deparaffinized, rehydrated and enzymatically disintegrated, and the cells in suspension were stained with propidium iodide and placed on microscope slides. A slight trend for an increased S-phase fraction in the peritumoral invading zone compared with the tumor core was observed (P=0.24). Additionally, there was a trend for a decrease in the overall survival time of patients with increasing peritumoral invading zone S-phase fraction (P=0.12). These data suggest that laser scanning cytometry is a powerful and clinically relevant tool for the objective analysis of the cell cycle in malignant gliomas. PMID:26998130

  18. Laser Scanning for the definition of high resolution topography in the Apuan Alps (IT) marble district

    NASA Astrophysics Data System (ADS)

    Riccucci, Silvia; Salvini, Riccardo; Francioni, Mirko

    2010-05-01

    The present paper describes the results of five laser scanning surveys performed by a Leica™ ScanStation2 with the aim of producing an high definition topography of a quarry, at the scale of 1:1,000. The project comes from a joint research carried out by the Authors in collaboration with the Local Sanitary Unit Agency (ASL n.1) of Massa and Carrara (IT). The main objective of this work has been the survey of both the exploited quarry walls and the upper residual and natural slopes. The area of interest is characterized by several quarry fronts which develop to variable and alternate directions to create very evident rock spurs, from NW-SE to NE-SW trending for a total wideness of about 2 hectares. Moreover, the quarry walls are sub-vertical and sometimes overhang by a total height of 100 m in respect to the quarry floor. Differential GPS and orthometric correction have been applied in order to co-register and to georeference the five point clouds; for these purposes a series of optical targets have been measured using a Laser Total Station. The subsequent phase has been the mesh construction and editing, from which a topographic map, 25 cm equidistance contours lines, has been created. The planimetric map shows the position and the geometry of crests, banks, escarpments, walls and all others exploitation features and the characteristics of the upper natural slopes. Morphological profiles along the maximum slope have been realized in order to better plan the future extractive activities according to the regional law. In order to make easier the prospective observation of detailed and overall areas, 3D views of multi-directional orientation have been realized. The produced data has been published by using the free LeicaTM TruView plug-in for Internet Explorer in a way to easily view the photographs and to measure the laser scan point clouds. Processing results have highlighted the higher spatial resolution of data coming from laser scanning in respect to the

  19. Gravity combined with laser-scan in Grotta Gigante: a benchmark cave for gravity studies

    NASA Astrophysics Data System (ADS)

    Pivetta, Tommaso; Braitenberg, Carla

    2014-05-01

    Laser scanning has become one of the most important topographic techniques in the last decades, due to its ability to reconstruct complex surfaces with high resolution and precision and due to its fast acquisition time. Recently a laser-scan survey has been acquired (Fingolo et al., 2011) in the "Grotta Gigante" cave near Trieste, Italy, the biggest cave worldwide according to the Guinness Awards. In this paper this survey is used to obtain a 3D discretization of the cave with prisms. Then through this new model, with the densities derived from campaign measurements, the exact gravimetric effect of the structure was computed (Nagy et al., 2000) and compared with the gravity observation at the surface. The transition from the cloud of laser-scan points to the prism model was carried out by different computer elaborations; first of all the reduction of the data density through an averaging process that allows to pass from over 10000 points/m2 to less than 10points/m2. Then the whole dataset was filtered from the outliers by the means of a simple quadratic surface that fit the data (Turner, 1999). The reduced data points should be divided into the 2 surfaces of top and bottom, that are used to define the prisms. This step was performed using the local regression method (Loess) to calculate a surface located halfway between top and bottom points. Once the top and bottom interfaces were obtained it was possible to get the final prism representation and calculate the gravity signal. The observed Bouguer field is explained very well by our model and the residuals are used to evaluate possible secondary caves. The final prism model together with the gravity database on surface and inside the cave form a perfect benchmark to test forward and inverse potential field algorithms. References Fingolo M., Facco L., Ceccato A., Breganze C., Paganini P., Cezza M., Grotta Gigante di Trieste. Tra realtà virtuale e rilievi 3D ad alta risoluzione, Veneto Geologi, 75, pp.21-25, 2011

  20. Capturing and modelling high-complex alluvial topography with UAS-borne laser scanning

    NASA Astrophysics Data System (ADS)

    Mandlburger, Gottfried; Wieser, Martin; Pfennigbauer, Martin

    2015-04-01

    Due to fluvial activity alluvial forests are zones of highest complexity and relief energy. Alluvial forests are dominated by new and pristine channels in consequence of current and historic flood events. Apart from topographic features, the vegetation structure is typically very complex featuring, both, dense under story as well as high trees. Furthermore, deadwood and debris carried from upstream during periods of high discharge within the river channel are deposited in these areas. Therefore, precise modelling of the micro relief of alluvial forests using standard tools like Airborne Laser Scanning (ALS) is hardly feasible. Terrestrial Laser Scanning (TLS), in turn, is very time consuming for capturing larger areas as many scan positions are necessary for obtaining complete coverage due to view occlusions in the forest. In the recent past, the technological development of Unmanned Arial Systems (UAS) has reached a level that light-weight survey-grade laser scanners can be operated from these platforms. For capturing alluvial topography this could bridge the gap between ALS and TLS in terms of providing a very detailed description of the topography and the vegetation structure due to the achievable very high point density of >100 points per m2. In our contribution we demonstrate the feasibility to apply UAS-borne laser scanning for capturing and modelling the complex topography of the study area Neubacher Au, an alluvial forest at the pre-alpine River Pielach (Lower Austria). The area was captured with Riegl's VUX-1 compact time-of-flight laser scanner mounted on a RiCopter (X-8 array octocopter). The scanner features an effective scan rate of 500 kHz and was flown in 50-100 m above ground. At this flying height the laser footprint is 25-50 mm allowing mapping of very small surface details. Furthermore, online waveform processing of the backscattered laser energy enables the retrieval of multiple targets for single laser shots resulting in a dense point cloud of

  1. Soil water erosion processes in mountain forest catchment - analysis by using terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Dąbek, Paweł; Żmuda, Romuald; Szczepański, Jakub; Ćmielewski, Bartłomiej; Patrzałek, Ciechosław

    2013-04-01

    The paper presents the results of the analysis of the water erosion processes of soil occurring in forestry mountain catchment area in the region of West Sudetes Mountain in Poland. The research was carried out within the experimental area of skid trails (operational trails), which were used to the end of 2010 in obtaining wood and its mechanical transport to the place of storage. As a consequence of forestry works that were carried out it was changing the natural structure of ground and its surface on the wooded slopes, which, combined with the favorable hydro-meteorological conditions contributed to the intensification of the water erosion processes of soil on surface of trails. For the implementation of the research project of the analysis of water erosion processes in the forestry catchment area innovative was used terrestrial laser scanning. Using terrestrial laser scanning has enabled the analysis of the dynamics of erosion processes both in time, as well as in spatial and quantitative terms. Scanning was performed at a resolution of 4 mm, resulting in 62 500 points per 1 square meter. After filtering the data were interpolated to other resolution of 1 cm, which can identify even the smallest linear and surface effects of erosion. While installed on the experimental area, along the skid trails, anti-erosion barriers in order to reduce transport eroded material and allow its accumulation. Allowed to precisely determine the location of areas of accumulation, the rate and amount of accumulated material. The result of the analyses that was carried out is identification areas of denudation of the eroded material, and also determine the intensity of the erosion processes and their quantitative analysis. The long-term researches on hydrological conditions and forest complexes functioning show that forest effectively stores water, limits linear and surface flow and delays water outflow from a catchment. Carried out a research project using the terrestrial laser

  2. Fusion of image and laser-scanning data in a large-scale 3D virtual environment

    NASA Astrophysics Data System (ADS)

    Shih, Jhih-Syuan; Lin, Ta-Te

    2013-05-01

    Construction of large-scale 3D virtual environment is important in many fields such as robotic navigation, urban planning, transportation, and remote sensing, etc. Laser scanning approach is the most common method used in constructing 3D models. This paper proposes an automatic method to fuse image and laser-scanning data in a large-scale 3D virtual environment. The system comprises a laser-scanning device installed on a robot platform and the software for data fusion and visualization. The algorithms of data fusion and scene integration are presented. Experiments were performed for the reconstruction of outdoor scenes to test and demonstrate the functionality of the system. We also discuss the efficacy of the system and technical problems involved in this proposed method.

  3. Design and development of multi functional confocal laser scanning microscope with UV / VIS laser source

    NASA Astrophysics Data System (ADS)

    Kanai, Yoshikazu; Kanzaki, Yousuke; Wakaki, Moriaki; Takeyama, Norihide

    2005-08-01

    A high resolution Confocal Laser Scanning Microscope (CLSM) with UV / VIS light sources was developed as the first step of multi-functional microscope. The optical system is designed to optimize for both UV and VIS wavelengths. An UV laser is used to achieve higher resolution, and a VIS is for multi functions. A new objective lens specialized for this application was designed and fabricated. Specification of the lens and the optical system is NA:0.95, EFL:2.5mm, WD:1.5mm, Resolution:160nm and achromatic for two wavelengths of UV 325.0nm / VIS 632.8nm. Several specimens were characterized to check the performance of the system. Some optical materials under study were measured for evaluation, and interesting results could be obtained. Multi-functional measurements are being planed as a next step. This system will help the research of nano-structures, photonic-crystals and biology.

  4. Evaluation of the Cytotoxic Behavior of Fungal Extracellular Synthesized Ag Nanoparticles Using Confocal Laser Scanning Microscope

    PubMed Central

    Salaheldin, Taher A.; Husseiny, Sherif M.; Al-Enizi, Abdullah M.; Elzatahry, Ahmed; Cowley, Alan H.

    2016-01-01

    Silver nanoparticles have been synthesized by subjecting a reaction medium to a Fusarium oxysporum biomass at 28 °C for 96 h. The biosynthesized Ag nanoparticles were characterized on the basis of their anticipated peak at 405 nm using UV-Vis-NIR spectroscopy. Structural confirmation was evident from the characteristic X-ray diffraction (XRD) pattern, high-resolution transmission electron Microscopy (HRTEM) and the particle size analyzer. The Ag nanoparticles were of dimension 40 ± 5 nm and spherical in shape. The study mainly focused on using the confocal laser scanning microscope (CLSM) to examine the cytotoxic activities of fungal synthesized Ag nanoparticles on a human breast carcinoma cell line MCF7 cell, which featured remarkable vacuolation, thus indicating a potent cytotoxic activity. PMID:26950118

  5. Model Based Viewpoint Planning for Terrestrial Laser Scanning from AN Economic Perspective

    NASA Astrophysics Data System (ADS)

    Wujanz, D.; Neitzel, F.

    2016-06-01

    Despite the enormous popularity of terrestrial laser scanners in the field of Geodesy, economic aspects in the context of data acquisition are mostly considered intuitively. In contrast to established acquisition techniques, such as tacheometry and photogrammetry, optimisation of the acquisition configuration cannot be conducted based on assumed object coordinates, as these would change in dependence to the chosen viewpoint. Instead, a combinatorial viewpoint planning algorithm is proposed that uses a given 3D-model as an input and simulates laser scans based on predefined viewpoints. The method determines a suitably small subset of viewpoints from which the sampled object surface is preferably large. An extension of the basic algorithm is proposed that only considers subsets of viewpoints that can be registered to a common dataset. After exemplification of the method, the expected acquisition time in the field is estimated based on computed viewpoint plans.

  6. Building Facade Documentation Using Laser Scanning and Photogrammetry and Data Implementation Into Bim

    NASA Astrophysics Data System (ADS)

    Faltýnová, M.; Matoušková, E.; Šedina, J.; Pavelka, K.

    2016-06-01

    A project started last year called MORE-CONNECT, which focuses on the renovation of buildings (especially building facades) using prefabricated elements. The aim of this project is to create a competitive solution consisting of a technology and processes which enable fast, cost-effective renovation with minimal difficulties to inhabitants. Significant cost savings in renovation costs lies in the usage of prefabricated elements and the reduction of construction works on site. The precision of the prefabricated element depends on the precision of the construction, project and building documentation. This article offers an overview of the possible methods for building documentation and spatial data transfer into BIM (Building Information Modelling) software. The description of methods focuses on laser scanning and photogrammetry (including RPAS based), its advantages, disadvantages and limitations according to the documented building, level of renovation, situation on site etc. The next part involves spatial data transfer into BIM software. A proposed solution is tested in a case study.

  7. Static terrestrial laser scanning of juvenile understory trees for field phenotyping

    NASA Astrophysics Data System (ADS)

    Wang, Huanhuan; Lin, Yi

    2014-11-01

    This study was to attempt the cutting-edge 3D remote sensing technique of static terrestrial laser scanning (TLS) for parametric 3D reconstruction of juvenile understory trees. The data for test was collected with a Leica HDS6100 TLS system in a single-scan way. The geometrical structures of juvenile understory trees are extracted by model fitting. Cones are used to model trunks and branches. Principal component analysis (PCA) is adopted to calculate their major axes. Coordinate transformation and orthogonal projection are used to estimate the parameters of the cones. Then, AutoCAD is utilized to simulate the morphological characteristics of the understory trees, and to add secondary branches and leaves in a random way. Comparison of the reference values and the estimated values gives the regression equation and shows that the proposed algorithm of extracting parameters is credible. The results have basically verified the applicability of TLS for field phenotyping of juvenile understory trees.

  8. Confocal laser scanning microscopy detection of chlorophylls and carotenoids in chloroplasts and chromoplasts of tomato fruit.

    PubMed

    D'Andrea, Lucio; Amenós, Montse; Rodríguez-Concepción, Manuel

    2014-01-01

    Plant cells are unique among eukaryotic cells because of the presence of plastids, including chloroplasts and chromoplasts. Chloroplasts are found in green tissues and harbor the photosynthetic machinery (including chlorophyll molecules), while chromoplasts are present in non-photosynthetic tissues and accumulate large amounts of carotenoids. During tomato fruit development, chloroplasts are converted into chromoplasts that accumulate high levels of lycopene, a linear carotenoid responsible for the characteristic red color of ripe fruit. Here, we describe a simple and fast method to detect both types of fully differentiated plastids (chloroplasts and chromoplasts), as well as intermediate stages, in fresh tomato fruits. The method is based on the differential autofluorescence of chlorophylls and carotenoids (lycopene) detected by Confocal Laser Scanning Microscopy.

  9. Spatiotemporal Rank Filtering Improves Image Quality Compared to Frame Averaging in 2-Photon Laser Scanning Microscopy.

    PubMed

    Pinkard, Henry; Corbin, Kaitlin; Krummel, Matthew F

    2016-01-01

    Live imaging of biological specimens using optical microscopy is limited by tradeoffs between spatial and temporal resolution, depth into intact samples, and phototoxicity. Two-photon laser scanning microscopy (2P-LSM), the gold standard for imaging turbid samples in vivo, has conventionally constructed images with sufficient signal-to-noise ratio (SNR) generated by sequential raster scans of the focal plane and temporal integration of the collected signals. Here, we describe spatiotemporal rank filtering, a nonlinear alternative to temporal integration, which makes more efficient use of collected photons by selectively reducing noise in 2P-LSM images during acquisition. This results in much higher SNR while preserving image edges and fine details. Practically, this allows for at least a four fold decrease in collection times, a substantial improvement for time-course imaging in biological systems.

  10. Compact multiphoton/single photon laser scanning microscope for spectral imaging and fluorescence lifetime imaging.

    PubMed

    Ulrich, Volker; Fischer, Peter; Riemann, Iris; Königt, Karsten

    2004-01-01

    An inverted fluorescence microscope was upgraded into a compact three-dimensional laser scanning microscope (LSM) of 65 x 62 x 48 cm dimensions by means of a fast kHz galvoscanner unit, a piezodriven z-stage, and a picosecond (ps) 50 MHz laser diode at 405 nm. In addition, compact turn-key near infrared femtosecond lasers have been employed to perform multiphoton fluorescence and second harmonic generation (SHG) microscopy. To expand the features of the compact LSM, a time-correlated single photon counting unit as well as a Sagnac interferometer have been added to realize fluorescence lifetime imaging (FLIM) and spectral imaging. Using this unique five-dimensional microscope, TauMap, single-photon excited (SPE), and two-photon excited (TPE) cellular fluorescence as well as intratissue autofluorescence of water plant leaves have been investigated with submicron spatial resolution, <270 ps temporal resolution, and 10 nm spectral resolution. PMID:15536977

  11. A handheld laser scanning confocal reflectance imaging–confocal Raman microspectroscopy system

    PubMed Central

    Patil, Chetan A.; Arrasmith, Christopher L.; Mackanos, Mark A.; Dickensheets, David L.; Mahadevan-Jansen, Anita

    2012-01-01

    Confocal reflectance microscopy and confocal Raman spectroscopy have shown potential for non-destructive analysis of samples at micron-scale resolutions. Current studies utilizing these techniques often employ large bench-top microscopes, and are not suited for use outside of laboratory settings. We have developed a microscope which combines laser scanning confocal reflectance imaging and confocal Raman spectroscopy into a compact handheld probe that is capable of high-resolution imaging and spectroscopy in a variety of settings. The compact size of the probe is largely due to the use of a MEMS mirror for beam scanning. The probe is capable of axial resolutions of up to 4 μm for the confocal imaging channel and 10 μm for the confocal Raman spectroscopy channel. Here, we report instrument design, characterize optical performance, and provide images and spectra from normal skin to demonstrate the instrument’s capabilities for clinical diagnostics. PMID:22435097

  12. Low cost and compact nonlinear (SHG/TPE) laser scanning endoscope for bio-medical application

    NASA Astrophysics Data System (ADS)

    Liu, Jiayun; Lim, Ken Choong; Li, Hao; Seck, Hon Luen; Yu, Xia; Kok, Shaw Wei; Zhang, Ying

    2015-03-01

    Two-photon fluorescence (TPE) and second harmonic generation (SHG) can been used to extract biological information from tissues at the molecular level, which is blind to traditional microscopes. Through these two image contrast mechanisms, a nonlinear laser scanning endoscope (NLSE) is able to image tissue cells and the extra cellular matrix (ECM) through a special fiber and miniaturized scanner without the requirement of poisonous chemical staining. Therefore, NLSE reserves high potential for in-vivo pathological study and disease diagnosis. However, the high cost and bulky size of a NLSE system has become one of the major issues preventing this technology from practical clinical operation. In this paper, we report a fiber laser based multi-modality NLSE system with compact size and low cost, ideal for in-vivo applications in clinical environments. The demonstration of the developed NLSE nonlinear imaging capability on different bio-structures in liver, retina and skin are also presented.

  13. The Use of Computer Vision Algorithms for Automatic Orientation of Terrestrial Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Markiewicz, Jakub Stefan

    2016-06-01

    The paper presents analysis of the orientation of terrestrial laser scanning (TLS) data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV) algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

  14. Characterization of acoustic lenses with the Foucault test by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Ahmed Mohamed, E. T.; Abdelrahman, A.; Pluta, M.; Grill, W.

    2010-03-01

    In this work, the Foucault knife-edge test, which has traditionally been known as the classic test for optical imaging devices, is used to characterize an acoustic lens for operation at 1.2 GHz. A confocal laser scanning microscope (CLSM) was used as the illumination and detection device utilizing its pinhole instead of the classical knife edge that is normally employed in the Foucault test. Information about the geometrical characteristics, such as the half opening angle of the acoustic lens, were determined as well as the quality of the calotte of the lens used for focusing. The smallest focal spot size that could be achieved with the examined lens employed as a spherical reflector was found to be about 1 μm. By comparison to the idealized resolution a degradation of about a factor of 2 can be deduced. This limits the actual quality of the acoustic focus.

  15. Fast 3D visualization of endogenous brain signals with high-sensitivity laser scanning photothermal microscopy

    PubMed Central

    Miyazaki, Jun; Iida, Tadatsune; Tanaka, Shinji; Hayashi-Takagi, Akiko; Kasai, Haruo; Okabe, Shigeo; Kobayashi, Takayoshi

    2016-01-01

    A fast, high-sensitivity photothermal microscope was developed by implementing a spatially segmented balanced detection scheme into a laser scanning microscope. We confirmed a 4.9 times improvement in signal-to-noise ratio in the spatially segmented balanced detection compared with that of conventional detection. The system demonstrated simultaneous bi-modal photothermal and confocal fluorescence imaging of transgenic mouse brain tissue with a pixel dwell time of 20 μs. The fluorescence image visualized neurons expressing yellow fluorescence proteins, while the photothermal signal detected endogenous chromophores in the mouse brain, allowing 3D visualization of the distribution of various features such as blood cells and fine structures probably due to lipids. This imaging modality was constructed using compact and cost-effective laser diodes, and will thus be widely useful in the life and medical sciences. PMID:27231615

  16. Analysis of the melanin distribution in different ethnic groups by in vivo laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Antoniou, C.; Lademann, J.; Richter, H.; Astner, S.; Patzelt, A.; Zastrow, L.; Sterry, W.; Koch, S.

    2009-05-01

    The aim of this study was to determine whether Laser scanning confocal microscopy (LSM) is able to visualize differences in melanin content and distribution in different Skin Phototypes. The investigations were carried out on six healthy volunteers with Skin Phototypes II, IV, and VI. Representative skin samples of Skin Phototypes II, V, and VI were obtained for histological analysis from remaining tissue of skin grafts and were used for LSM-pathologic correlation. LSM evaluation showed significant differences in melanin distribution in Skin Phototypes II, IV, and VI, respectively. Based on the differences in overall reflectivity and image brightness, a visual evaluation scheme showed increasing brightness of the basal and suprabasal layers with increasing Skin Phototypes. The findings correlated well with histological analysis. The results demonstrate that LSM may serve as a promising adjunctive tool for real time assessment of melanin content and distribution in human skin, with numerous clinical applications and therapeutic and preventive implications.

  17. Characterization of fibrillar collagen types using multi-dimensional multiphoton laser scanning microscopy.

    PubMed

    Lutz, V; Sattler, M; Gallinat, S; Wenck, H; Poertner, R; Fischer, F

    2012-04-01

    In dermal photodamage the ratio of the collagen types III to I changes. This makes the investigation of the fibrillar collagen type characteristics interesting for skin research. In this study collagen types were characterized using 5-dimensional multiphoton laser scanning microscopy (5D-IVT) that can be applied in vivo. Second harmonic generation (SHG) signals and fluorescence lifetimes of the collagen autofluorescence were analysed. Collagen type I generates a higher SHG intensity and a longer fluorescence lifetime compared to collagen type III. Thus, the SHG intensity decrease found in photodamaged skin might be explained by the increase in collagen type III. Calculating the in vivo relevant increase of collagen type III gives a negligible difference in fluorescence lifetime not qualifying this method for the determination of collagen type changes in dermal photodamage in vivo in human skin. However, for pathologies that exhibit higher differences in collagen types 5D-IVT analysis might be a suitable method.

  18. Using Mobile Laser Scanning Data for Features Extraction of High Accuracy Driving Maps

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Liu, Yuan; Liang, Fuxun; Dong, Zhen

    2016-06-01

    High Accuracy Driving Maps (HADMs) are the core component of Intelligent Drive Assistant Systems (IDAS), which can effectively reduce the traffic accidents due to human error and provide more comfortable driving experiences. Vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. This paper proposes a novel method to extract road features (e.g., road surfaces, road boundaries, road markings, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, vehicles and so on) for HADMs in highway environment. Quantitative evaluations show that the proposed algorithm attains an average precision and recall in terms of 90.6% and 91.2% in extracting road features. Results demonstrate the efficiencies and feasibilities of the proposed method for extraction of road features for HADMs.

  19. Object shape classification and scene shape representation for three-dimensional laser scanned outdoor data

    NASA Astrophysics Data System (ADS)

    Ning, Xiaojuan; Wang, Yinghui; Zhang, Xiaopeng

    2013-02-01

    Shape analysis of a three-dimensional (3-D) scene is an important issue and could be widely used for various applications: city planning, robot navigation, virtual tourism, etc. We introduce an approach for understanding the primitive shape of the scene to reveal the semantic scene shape structure and represent the scene using shape elements. The scene objects are labeled and recognized using the geometric and semantic features for each cluster, which is based on the knowledge of scene. Furthermore, the object in scene with a different primitive shape could also be classified and fitted using the Gaussian map of the segmented scene. We demonstrate the presented approach on several complex scenes from laser scanning. According to the experimental result, the proposed method can accurately represent the geometric structure of the 3-D scene.

  20. An alternative method of promoter assessment by confocal laser scanning microscopy.

    PubMed

    Sahoo, Dipak K; Ranjan, Rajiv; Kumar, Deepak; Kumar, Alok; Sahoo, Bhabani S; Raha, Sumita; Maiti, Indu B; Dey, Nrisingha

    2009-10-01

    A rapid and useful method of promoter activity analysis using techniques of confocal laser scanning microscopy (CLSM) is described in the present study. The activities of some pararetroviral promoters such as CaMV35S (Cauliflower mosaic virus), FMVSgt3 (Figwort mosaic virus sub-genomic transcript) and MMVFLt12 (Mirabilis mosaic virus full-length transcript) coupled to GFP (green fluorescent protein) and GUS (beta-glucuronidase) reporter genes were determined simultaneously by the CLSM technique and other available conventional methods for reporter gene assay based on relevant biochemical and molecular approaches. Consistent and comparable results obtained by CLSM as well as by other conventional assay methods confirm the effectiveness of the CLSM approach for assessment of promoter activity. Hence the CLSM method can be suggested as an alternative way for promoter analysis on the basis of high throughput.

  1. Evaluation of the Cytotoxic Behavior of Fungal Extracellular Synthesized Ag Nanoparticles Using Confocal Laser Scanning Microscope.

    PubMed

    Salaheldin, Taher A; Husseiny, Sherif M; Al-Enizi, Abdullah M; Elzatahry, Ahmed; Cowley, Alan H

    2016-03-03

    Silver nanoparticles have been synthesized by subjecting a reaction medium to a Fusarium oxysporum biomass at 28 °C for 96 h. The biosynthesized Ag nanoparticles were characterized on the basis of their anticipated peak at 405 nm using UV-Vis-NIR spectroscopy. Structural confirmation was evident from the characteristic X-ray diffraction (XRD) pattern, high-resolution transmission electron Microscopy (HRTEM) and the particle size analyzer. The Ag nanoparticles were of dimension 40 ± 5 nm and spherical in shape. The study mainly focused on using the confocal laser scanning microscope (CLSM) to examine the cytotoxic activities of fungal synthesized Ag nanoparticles on a human breast carcinoma cell line MCF7 cell, which featured remarkable vacuolation, thus indicating a potent cytotoxic activity.

  2. Further study of trichosanthin's effect on mouse embryos with confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Xu, Hui; Zhang, Chunyang; Ma, Hui; Chen, Die Yan

    2001-09-01

    Trichosanthin(TCS), a ribosome inactivating protein extracted from the root tuber of a traditional Chinese medicine herb Tian Huo Fen(THF), possessed abortifacient, anti-tumor and anti-human immunodeficiency virus(HIV) activities. For centuries in China, THF has been used as an effective folk medicine to terminate early and midtrimester pregnancies and to treat ectopic pregnancies, hydatidiform moles and trophoblastic tumor. We observed the changes in reactive oxygen species and intracellular calcium in mouse embryos induced by TCS with confocal laser scanning microscopy in combination with the fluorescene diacetate (DCFHDA) and Fluo-3-AM. The results indicated that TCS induced increase in intracellular calcium and production of reactive oxygen species in mouse embryos , and TCS inhibited the development of mouse embryos effectively. Mouse embryos of different developmental stages before implantation are used in the experiments. This provides new insight into mechanism for abortifacient activity of TCS.

  3. Fluorescence Readout of a Patch Clamped Membrane by Laser Scanning Microscopy.

    PubMed

    Gerhardt, Matthias; Walz, Michael; Beta, Carsten

    2016-01-01

    In this chapter, we describe how to shield a patch of a cell membrane against extracellularly applied chemoattractant stimuli. Classical patch clamp methodology is applied to allow for controlled shielding of a membrane patch by measuring the seal resistivity. In Dictyostelium cells, a seal resistivity of 50 MΩ proved to be tight enough to exclude molecules from diffusing into the shielded membrane region. This allowed for separating a shielded and a non-shielded region of a cell membrane to study the spatiotemporal dynamics of intracellular chemotactic signaling events at the interface between shielded and non-shielded areas. The spatiotemporal dynamics of signaling events in the membrane was read out by means of appropriate fluorescent markers using laser scanning confocal microscopy. PMID:27271912

  4. Geometric validation of a mobile laser scanning system for urban applications

    NASA Astrophysics Data System (ADS)

    Guan, Haiyan; Li, Jonathan; Yu, Yongtao; Liu, Yan

    2016-03-01

    Mobile laser scanning (MLS) technologies have been actively studied and implemented over the past decade, as their application fields are rapidly expanding and extending beyond conventional topographic mapping. Trimble's MX-8, as one of the MLS systems in the current market, generates rich survey-grade laser and image data for urban surveying. The objective of this study is to evaluate whether Trimble MX-8 MLS data satisfies the accuracy requirements of urban surveying. According to the formula of geo-referencing, accuracies of navigation solution and laser scanner determines the accuracy of the collected LiDAR point clouds. Two test sites were selected to test the performance of Trimble MX-8. Those extensive tests confirm that Trimble MX-8 offers a very promising tool to survey complex urban areas.

  5. Pharmaceutical applications of confocal laser scanning microscopy: the physical characterisation of pharmaceutical systems.

    PubMed

    Pygall, Samuel R; Whetstone, Joanne; Timmins, Peter; Melia, Colin D

    2007-12-10

    The application of confocal laser scanning microscopy (CLSM) to the physicochemical characterisation of pharmaceutical systems is not as widespread as its application within the field of cell biology. However, methods have been developed to exploit the imaging capabilities of CLSM to study a wide range of pharmaceutical systems, including phase-separated polymers, colloidal systems, microspheres, pellets, tablets, film coatings, hydrophilic matrices, and chromatographic stationary phases. Additionally, methods to measure diffusion in gels, bioadhesives, and for monitoring microenvironmental pH change within dosage forms have been utilised. CLSM has also been used in the study of the physical interaction of dosage forms with biological barriers such as the eye, skin and intestinal epithelia, and in particular, to determine the effectiveness of a plethora of pharmaceutical systems to deliver drugs through these barriers. In the future, there is continuing scope for wider exploitation of existing techniques, and continuing advancements in instrumentation.

  6. Low temperature laser scanning microscopy of a superconducting radio-frequency cavity.

    PubMed

    Ciovati, G; Anlage, Steven M; Baldwin, C; Cheng, G; Flood, R; Jordan, K; Kneisel, P; Morrone, M; Nemes, G; Turlington, L; Wang, H; Wilson, K; Zhang, S

    2012-03-01

    An apparatus was developed to obtain, for the first time, 2D maps of the surface resistance of the inner surface of an operating superconducting radio-frequency niobium cavity by a low-temperature laser scanning microscopy technique. This allows identifying non-uniformities of the surface resistance with a spatial resolution of about 2.4 mm and surface resistance resolution of ~1 μΩ at 3.3 GHz. A signal-to-noise ratio of about 10 dB was obtained with 240 mW laser power and 1 Hz modulation frequency. The various components of the apparatus, the experimental procedure and results are discussed in detail in this contribution.

  7. Lateral resolution improvement of laser-scanning imaging for nano defects detection

    NASA Astrophysics Data System (ADS)

    Yokozeki, Hiroki; Kudo, Ryota; Takahashi, Satoru; Takamasu, Kiyoshi

    2014-08-01

    Demand for higher efficiency in the semiconductor manufacturing industry is continually increasing. In particular, nano defects measurement on patterned or bare Si semiconductor wafer surfaces is an important quality control factor for realizing high productivity and reliability of semiconductor device fabrication. Optical methods and electron beam methods are conventionally used for the inspection of semiconductor wafers. Because they are nondestructive and suitable for high-throughput inspection, optical methods are preferable to electron beam methods such as scanning electron microscopy, transmission electron microscopy, and so on. However, optical methods generally have an essential disadvantage about lateral spatial resolution than electron beam methods, because of the diffraction limit depending on the optical wavelength. In this research, we aim to develop a novel laser-scanning imaging method that can be applied to nano-/micro manufacturing processes such as semiconductor wafer surface inspection to allow lateral spatial super-resolution imaging with resolution beyond the diffraction limit. In our proposed method, instead of detecting the light intensity value from the beam spot on the inspection surface, the light intensity distribution, which is formed with infinity corrected optical system, coming from the beam spot on the inspection surface is detected. In addition, nano scale shifts in the beam spot are applied for laser spot scanning using a conventional laser-scanning method in which the spots are shifted at about a 100 nm pitch. By detecting multiple light intensity distributions due to the nano scale shifts, a super-resolution image reconstruction with resolution beyond the diffraction limit can be expected. In order to verify the feasibility of the proposed method, several numerical simulations were carried out.

  8. Automatic Feature Detection, Description and Matching from Mobile Laser Scanning Data and Aerial Imagery

    NASA Astrophysics Data System (ADS)

    Hussnain, Zille; Oude Elberink, Sander; Vosselman, George

    2016-06-01

    In mobile laser scanning systems, the platform's position is measured by GNSS and IMU, which is often not reliable in urban areas. Consequently, derived Mobile Laser Scanning Point Cloud (MLSPC) lacks expected positioning reliability and accuracy. Many of the current solutions are either semi-automatic or unable to achieve pixel level accuracy. We propose an automatic feature extraction method which involves utilizing corresponding aerial images as a reference data set. The proposed method comprise three steps; image feature detection, description and matching between corresponding patches of nadir aerial and MLSPC ortho images. In the data pre-processing step the MLSPC is patch-wise cropped and converted to ortho images. Furthermore, each aerial image patch covering the area of the corresponding MLSPC patch is also cropped from the aerial image. For feature detection, we implemented an adaptive variant of Harris-operator to automatically detect corner feature points on the vertices of road markings. In feature description phase, we used the LATCH binary descriptor, which is robust to data from different sensors. For descriptor matching, we developed an outlier filtering technique, which exploits the arrangements of relative Euclidean-distances and angles between corresponding sets of feature points. We found that the positioning accuracy of the computed correspondence has achieved the pixel level accuracy, where the image resolution is 12cm. Furthermore, the developed approach is reliable when enough road markings are available in the data sets. We conclude that, in urban areas, the developed approach can reliably extract features necessary to improve the MLSPC accuracy to pixel level.

  9. Fine micro-welding of thin metal sheet by high speed laser scanning

    NASA Astrophysics Data System (ADS)

    Okamoto, Yasuhiro; Gillner, Arnold; Olowinsky, Alexander; Gedicke, Jens; Uno, Yoshiyuki

    2007-05-01

    Recently, since the size of component becomes smaller, then the welding of thin metal sheet has been required. Besides, the flexibility of process is important according to the accessibility especially for small components. Fraunhofer Institute for Laser Technology had developed the SHADOW ® welding technology, in which the high speed joining with small distortion is possible using pulsed Nd:YAG laser. The possibility of high speed and high quality welding had been reported by using single-mode fiber laser. The combination of micro beam and high speed laser scanning has the advantages for thin metal sheet welding. Therefore, the characteristics of micro-welding for thin metal sheet were investigated by high speed laser scanning, in which the welding was carried out by high speed scanner system with single-mode fiber laser and pulsed Nd:YAG laser. The proper welding region was narrow by the laser beam with a large focus diameter of 160 μm without pulse control, while a small focus diameter of 22 μm can control the welding state widely. A small focus diameter can perform the excellent welding seam from the extreme beginning without pulse control. The penetration depth can be controlled by the energy density with a small focus diameter of 22 μm at the energy densities less than 1 J/mm2. Besides, the unique periodic structure appeared at the high velocity of beam scanning with a small focus diameter. Moreover, the overlap welding of 25 μm thickness sheet can be performed regardless of small gap distance between two sheets by the laser beam with a small focus diameter of 22 μm.

  10. Robust Locally Weighted Regression For Ground Surface Extraction In Mobile Laser Scanning 3D Data

    NASA Astrophysics Data System (ADS)

    Nurunnabi, A.; West, G.; Belton, D.

    2013-10-01

    A new robust way for ground surface extraction from mobile laser scanning 3D point cloud data is proposed in this paper. Fitting polynomials along 2D/3D points is one of the well-known methods for filtering ground points, but it is evident that unorganized point clouds consist of multiple complex structures by nature so it is not suitable for fitting a parametric global model. The aim of this research is to develop and implement an algorithm to classify ground and non-ground points based on statistically robust locally weighted regression which fits a regression surface (line in 2D) by fitting without any predefined global functional relation among the variables of interest. Afterwards, the z (elevation)-values are robustly down weighted based on the residuals for the fitted points. The new set of down weighted z-values along with x (or y) values are used to get a new fit of the (lower) surface (line). The process of fitting and down-weighting continues until the difference between two consecutive fits is insignificant. Then the final fit represents the ground level of the given point cloud and the ground surface points can be extracted. The performance of the new method has been demonstrated through vehicle based mobile laser scanning 3D point cloud data from urban areas which include different problematic objects such as short walls, large buildings, electric poles, sign posts and cars. The method has potential in areas like building/construction footprint determination, 3D city modelling, corridor mapping and asset management.

  11. Feature-Based Laser Scan Matching and Its Application for Indoor Mapping.

    PubMed

    Li, Jiayuan; Zhong, Ruofei; Hu, Qingwu; Ai, Mingyao

    2016-01-01

    Scan matching, an approach to recover the relative position and orientation of two laser scans, is a very important technique for indoor positioning and indoor modeling. The iterative closest point (ICP) algorithm and its variants are the most well-known techniques for such a problem. However, ICP algorithms rely highly on the initial guess of the relative transformation, which will reduce its power for practical applications. In this paper, an initial-free 2D laser scan matching method based on point and line features is proposed. We carefully design a framework for the detection of point and line feature correspondences. First, distinct feature points are detected based on an extended 1D SIFT, and line features are extracted via a modified Split-and-Merge algorithm. In this stage, we also give an effective strategy for discarding unreliable features. The point and line features are then described by a distance histogram; the pairs achieving best matching scores are accepted as potential correct correspondences. The histogram cluster technique is adapted to filter outliers and provide an accurate initial value of the rigid transformation. We also proposed a new relative pose estimation method that is robust to outliers. We use the lq-norm (0 < q < 1) metric in this approach, in contrast to classic optimization methods whose cost function is based on the l₂-norm of residuals. Extensive experiments on real data demonstrate that the proposed method is almost as accurate as ICPs and is initial free. We also show that our scan matching method can be integrated into a simultaneous localization and mapping (SLAM) system for indoor mapping. PMID:27517932

  12. Feature-Based Laser Scan Matching and Its Application for Indoor Mapping

    PubMed Central

    Li, Jiayuan; Zhong, Ruofei; Hu, Qingwu; Ai, Mingyao

    2016-01-01

    Scan matching, an approach to recover the relative position and orientation of two laser scans, is a very important technique for indoor positioning and indoor modeling. The iterative closest point (ICP) algorithm and its variants are the most well-known techniques for such a problem. However, ICP algorithms rely highly on the initial guess of the relative transformation, which will reduce its power for practical applications. In this paper, an initial-free 2D laser scan matching method based on point and line features is proposed. We carefully design a framework for the detection of point and line feature correspondences. First, distinct feature points are detected based on an extended 1D SIFT, and line features are extracted via a modified Split-and-Merge algorithm. In this stage, we also give an effective strategy for discarding unreliable features. The point and line features are then described by a distance histogram; the pairs achieving best matching scores are accepted as potential correct correspondences. The histogram cluster technique is adapted to filter outliers and provide an accurate initial value of the rigid transformation. We also proposed a new relative pose estimation method that is robust to outliers. We use the lq-norm (0 < q < 1) metric in this approach, in contrast to classic optimization methods whose cost function is based on the l2-norm of residuals. Extensive experiments on real data demonstrate that the proposed method is almost as accurate as ICPs and is initial free. We also show that our scan matching method can be integrated into a simultaneous localization and mapping (SLAM) system for indoor mapping. PMID:27517932

  13. Street-side vehicle detection, classification and change detection using mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Xiao, Wen; Vallet, Bruno; Schindler, Konrad; Paparoditis, Nicolas

    2016-04-01

    Statistics on street-side car parks, e.g. occupancy rates, parked vehicle types, parking durations, are of great importance for urban planning and policy making. Related studies, e.g. vehicle detection and classification, mostly focus on static images or video. Whereas mobile laser scanning (MLS) systems are increasingly utilized for urban street environment perception due to their direct 3D information acquisition, high accuracy and movability. In this paper, we design a complete system for car park monitoring, including vehicle recognition, localization, classification and change detection, from laser scanning point clouds. The experimental data are acquired by an MLS system using high frequency laser scanner which scans the streets vertically along the system's moving trajectory. The point clouds are firstly classified as ground, building façade, and street objects which are then segmented using state-of-the-art methods. Each segment is treated as an object hypothesis, and its geometric features are extracted. Moreover, a deformable vehicle model is fitted to each object. By fitting an explicit model to the vehicle points, detailed information, such as precise position and orientation, can be obtained. The model parameters are also treated as vehicle features. Together with the geometric features, they are applied to a supervised learning procedure for vehicle or non-vehicle recognition. The classes of detected vehicles are also investigated. Whether vehicles have changed across two datasets acquired at different times is detected to estimate the durations. Here, vehicles are trained pair-wisely. Two same or different vehicles are paired up as training samples. As a result, the vehicle recognition, classification and change detection accuracies are 95.9%, 86.0% and 98.7%, respectively. Vehicle modelling improves not only the recognition rate, but also the localization precision compared to bounding boxes.

  14. Adhesion of rice flour-based batter to chicken drumsticks evaluated by laser scanning confocal microscopy and texture analysis.

    PubMed

    Mukprasirt, A; Herald, T J; Boyle, D L; Rausch, K D

    2000-09-01

    The convenience and appeal of battered or breaded products have resulted in a sales increase of 100% since 1980. Because of the rapid growth of the Asian-American population and increasing consumption of rice and rice products, rice flour is a logical alternative for wheat flour in traditional batter formulation. The effects of ingredients used in rice flour-based batters on adhesion characteristic for deep-fat fried chicken drumsticks were studied by laser scanning confocal microscopy (LSCM) and texture analysis. Raw chicken drumsticks were predusted with egg albumin powder before dipping into batters prepared from combinations of rice flour, yellow corn flour, oxidized cornstarch, methylcellulose, or xanthan gum. The drumsticks were fried at 175+/-5 C until the internal temperature reached at least 71 C. For LSCM, samples were fixed overnight and were sectioned by vibratome (200 microm) before viewing. Batter adhesion was determined using an attachment specifically designed for chicken drumsticks. Microstructural analysis showed that batter formulated with a 50:50 mixture of rice and corn flours adhered better to drumsticks than batter with other rice flour ratios. Xanthan gum (0.2%) or methylcellulose (0.3%) alone had poor adhesion to chicken skin. However, when combined with other ingredients, xanthan gum increased the amount of batter pick-up before frying by increasing viscosity. Egg albumin significantly facilitated batter adhesion. The results from texture analysis supported the microstructural studies. As rice flour ratio increased from 50 to 70%, the binding force decreased. Rice flour showed potential as an alternative to wheat flour for batter formulas when the appropriate levels of oxidized starch, xanthan gum, and methylcellulose were included in the formulation.

  15. Penetrability of AH plus and MTA fillapex after endodontic treatment and retreatment: a confocal laser scanning microscopy study.

    PubMed

    Kok, Daniela; Rosa, Ricardo Abreu da; Barreto, Mirela Sangoi; Busanello, Fernanda Hoffmann; Santini, Manuela Favarin; Pereira, Jefferson Ricardo; Só, Marcus Vinícius Reis

    2014-06-01

    The aim of the study was to assess the penetrability of two endodontic sealers (AH Plus and MTA Fillapex) into dentinal tubules, submitted to endodontic treatment and subsequently to endodontic retreatment. Thirty ex vivo incisors were prepared using ProTaper rotary system up to F3 instrument and divided in three groups according to the endodontic sealer used for root canal filling: AH Plus (AHP), MTA Fillapex (MTAF), and control group (CG) without using EDTA previously to the root canal filling. Rhodamine B dye (red) was incorporated to the sealers in order to provide the fluorescence which will enable confocal laser scanning microscopy (CLSM) assessment. All specimens were filled with gutta-percha cones using the lateral compaction technique. The specimens were submitted to endodontic retreatment using ProTaper Retreatment system, re-prepared up to F5 instruments and filled with gutta-percha cones and the same sealer used during endodontic retreatment. Fluorescein dye (green) was incorporated to the sealer in order to distinguish from the first filling. The roots were sectioned 2 mm from the apex and assessed by CLSM. No difference was found between the two experimental groups (P > 0.05). On the other hand, in the control group the sealers were not capable to penetrate into dentinal tubules after endodontic treatment (P > 0.05). In retreatment cases, none of the sealers were able to penetrate into dentin tubules. It can be concluded that sealer penetrability is high during endodontic treatment. However, MTA Fillapex and AH Plus do not penetrate into dentinal tubules after endodontic retreatment.

  16. USE OF MULTIPHOTON LASER SCANNING MICROSCOPY TO IMAGE BENZO[A]PYRENE AND METABOLITES IN FISH EARLY LIFE STAGES

    EPA Science Inventory

    Multiphoton laser scanning micrsocopy holds promise as a tool to study the tissue distribution of environmental chemical contaminants during fish early life stage development. One such chemical for which this is possible is benzo[a]pyrene (BaP), a polyaromatic hydrocarbon that a...

  17. Correcting spherical aberrations in a biospecimen using a transmissive liquid crystal device in two-photon excitation laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Tanabe, Ayano; Hibi, Terumasa; Ipponjima, Sari; Matsumoto, Kenji; Yokoyama, Masafumi; Kurihara, Makoto; Hashimoto, Nobuyuki; Nemoto, Tomomi

    2015-10-01

    Two-photon excitation laser scanning microscopy has enabled the visualization of deep regions in a biospecimen. However, refractive-index mismatches in the optical path cause spherical aberrations that degrade spatial resolution and the fluorescence signal, especially during observation at deeper regions. Recently, we developed transmissive liquid-crystal devices for correcting spherical aberration without changing the basic design of the optical path in a conventional laser scanning microscope. In this study, the device was inserted in front of the objective lens and supplied with the appropriate voltage according to the observation depth. First, we evaluated the device by observing fluorescent beads in single- and two-photon excitation laser scanning microscopes. Using a 25× water-immersion objective lens with a numerical aperture of 1.1 and a sample with a refractive index of 1.38, the device recovered the spatial resolution and the fluorescence signal degraded within a depth of ±0.6 mm. Finally, we implemented the device for observation of a mouse brain slice in a two-photon excitation laser scanning microscope. An optical clearing reagent with a refractive index of 1.42 rendered the fixed mouse brain transparent. The device improved the spatial resolution and the yellow fluorescent protein signal within a depth of 0-0.54 mm.

  18. USE OF MULTIPHOTON LASER SCANNING MICROSCOPY TO IMAGE BENZO[A]PYRENE AND METABOLITES IN FISH EGGS

    EPA Science Inventory

    Multiphoton laser scanning microscopy (MPLSM) is a promising tool to study the tissue distribution of environmental chemical contaminants during fish early life stages. One such chemical for which this is possible is benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon that a...

  19. The illuminating role of laser scanning digital elevation models in precision agriculture experimental designs - an agro-ecology perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laser scanning data streams, when linked with multi-spectral, hyperspectral, apparent soil electro-conductivity (ECa), or other kinds of geo-referenced data streams, aid in the creation of maps that allow useful applications in agricultural systems. These combinations of georeferenced information p...

  20. Accuracy in estimation of timber assortments and stem distribution - A comparison of airborne and terrestrial laser scanning techniques

    NASA Astrophysics Data System (ADS)

    Kankare, Ville; Vauhkonen, Jari; Tanhuanpää, Topi; Holopainen, Markus; Vastaranta, Mikko; Joensuu, Marianna; Krooks, Anssi; Hyyppä, Juha; Hyyppä, Hannu; Alho, Petteri; Viitala, Risto

    2014-11-01

    Detailed information about timber assortments and diameter distributions is required in forest management. Forest owners can make better decisions concerning the timing of timber sales and forest companies can utilize more detailed information to optimize their wood supply chain from forest to factory. The objective here was to compare the accuracies of high-density laser scanning techniques for the estimation of tree-level diameter distribution and timber assortments. We also introduce a method that utilizes a combination of airborne and terrestrial laser scanning in timber assortment estimation. The study was conducted in Evo, Finland. Harvester measurements were used as a reference for 144 trees within a single clear-cut stand. The results showed that accurate tree-level timber assortments and diameter distributions can be obtained, using terrestrial laser scanning (TLS) or a combination of TLS and airborne laser scanning (ALS). Saw log volumes were estimated with higher accuracy than pulpwood volumes. The saw log volumes were estimated with relative root-mean-squared errors of 17.5% and 16.8% with TLS and a combination of TLS and ALS, respectively. The respective accuracies for pulpwood were 60.1% and 59.3%. The differences in the bucking method used also caused some large errors. In addition, tree quality factors highly affected the bucking accuracy, especially with pulpwood volume.

  1. Correcting spherical aberrations in a biospecimen using a transmissive liquid crystal device in two-photon excitation laser scanning microscopy.

    PubMed

    Tanabe, Ayano; Hibi, Terumasa; Ipponjima, Sari; Matsumoto, Kenji; Yokoyama, Masafumi; Kurihara, Makoto; Hashimoto, Nobuyuki; Nemoto, Tomomi

    2015-10-01

    Two-photon excitation laser scanning microscopy has enabled the visualization of deep regions in a biospecimen. However, refractive-index mismatches in the optical path cause spherical aberrations that degrade spatial resolution and the fluorescence signal, especially during observation at deeper regions. Recently, we developed transmissive liquid-crystal devices for correcting spherical aberration without changing the basic design of the optical path in a conventional laser scanning microscope. In this study, the device was inserted in front of the objective lens and supplied with the appropriate voltage according to the observation depth. First, we evaluated the device by observing fluorescent beads in single- and two-photon excitation laser scanning microscopes. Using a 25× water-immersion objective lens with a numerical aperture of 1.1 and a sample with a refractive index of 1.38, the device recovered the spatial resolution and the fluorescence signal degraded within a depth of 0.6 mm. Finally, we implemented the device for observation of a mouse brain slice in a two-photon excitation laser scanning microscope. An optical clearing reagent with a refractive index of 1.42 rendered the fixed mouse brain transparent. The device improved the spatial resolution and the yellow fluorescent protein signal within a depth of 0-0.54 mm. PMID:26244766

  2. Correcting spherical aberrations in a biospecimen using a transmissive liquid crystal device in two-photon excitation laser scanning microscopy.

    PubMed

    Tanabe, Ayano; Hibi, Terumasa; Ipponjima, Sari; Matsumoto, Kenji; Yokoyama, Masafumi; Kurihara, Makoto; Hashimoto, Nobuyuki; Nemoto, Tomomi

    2015-10-01

    Two-photon excitation laser scanning microscopy has enabled the visualization of deep regions in a biospecimen. However, refractive-index mismatches in the optical path cause spherical aberrations that degrade spatial resolution and the fluorescence signal, especially during observation at deeper regions. Recently, we developed transmissive liquid-crystal devices for correcting spherical aberration without changing the basic design of the optical path in a conventional laser scanning microscope. In this study, the device was inserted in front of the objective lens and supplied with the appropriate voltage according to the observation depth. First, we evaluated the device by observing fluorescent beads in single- and two-photon excitation laser scanning microscopes. Using a 25× water-immersion objective lens with a numerical aperture of 1.1 and a sample with a refractive index of 1.38, the device recovered the spatial resolution and the fluorescence signal degraded within a depth of 0.6 mm. Finally, we implemented the device for observation of a mouse brain slice in a two-photon excitation laser scanning microscope. An optical clearing reagent with a refractive index of 1.42 rendered the fixed mouse brain transparent. The device improved the spatial resolution and the yellow fluorescent protein signal within a depth of 0-0.54 mm.

  3. 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.

  4. Measuring peatland morphology and eco-hydrological condition with laser scanning and spatial statistics

    NASA Astrophysics Data System (ADS)

    Bennie, J. J.; Anderson, K.

    2008-12-01

    with the biological survey, a ground-based high definition laser scanning instrument was used to measure the structural patterns in the bog microtopography. The spatial resolution of the laser scanning data was 2 cm at a distance of 20 m. Geostatistical variogram analysis was applied to the laser scanning data, for modelling the spatial character of each site. Results demonstrate that bog surfaces of different hydrological status show different scales of spatial pattern (semivariogram ranges typically < 1 m for active raised bog with characteristic Sphagnum hummock/hollow topography, ~ 4 m for drained and degraded bog dominated by a dwarf shrub canopy). At larger scales variation in the peat/vegetation surface level is associated with lowering of the water table. More recent work has shown the upscaling potential of this technique, where similar spatial statistical indicators have been measured using airborne LiDAR with a horizontal resolution of around 0.8 points per metre, allowing the application of this technique over the entire hydrological unit. Preliminary analysis at this suggests that a simple measure of semivariance at a lag distance of 5 m is sufficient to distinguish between areas of intact bog and drained and degraded bog (p < 0.05). These methods show promising potential for the large-scale monitoring and mapping of surface pattern as an indicator of hydrological and ecological status in peatlands.

  5. Airborne Laser Scanning as an effective tool for disaster mapping over mountainous forested landscapes

    NASA Astrophysics Data System (ADS)

    Azahari Razak, Khamarrul; van Westen, Cees; Straatsma, Menno; Malet, Jean-Philippe; de Jong, Steven M.

    2010-05-01

    The emergence of airborne laser scanning (ALS), initially as a research tool and in the last decade as a commercial capability has provided a powerful means to characterize the natural features and man-made structures within mountainous forested landscapes. ALS is capable of delivering very dense point clouds of a landscape in a relatively short time. Furthermore, ALS is able to operate during the night and highly accurate because of laser ranging accuracy and precise sensor platform supported by an integrated position and orientation system. The capability of ALS to obtain both ground and non-ground points leads to produce a high-quality digital terrain model and to retrieve detailed information from non-ground points (e.g. vegetation, building). Rapid mapping over spatial scales is one of the essential aspects for emergency response in dealing with hazard and risk assessment in mountainous environment. To date, many national agencies, private industries and research institutes utilize products derived from ALS data for disaster management. In order for the data to be effectively use by the end-users or decision-makers, a number of consideration at pre, during and post ALS data acquisition stages are required. This paper provides recommendations at planning stages, measurement phases, point cloud processing and products derivation throughout ALS data acquisition over rugged forested terrain based on Bois Noir catchment dataset in Barcelonnette, France. This catchment is highly affected by landslide hazards and located within climatic, lithological and geomorphological condition of the Southern French Alps. Airborne laser scanning data over the 100-years old forest in Bois Noir catchment was captured in July 2009 using a RIEGL laser scanner mounted on a helicopter. Airborne laser scanning differs in terms of typical project size, measurement techniques, scanning mechanism, positional accuracy and resolution of derived-products. Selection of laser sensor, number of

  6. Long term monitoring of geomorphological changes caused by torrent activity using terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Prokop, A.; Chiari, M.

    2012-04-01

    Torrential processes present a serious hazard in alpine regions. Especially sediment transport is responsible for most torrent related damages. The material incorporated in torrents is inherently complex, varying from clay sized solids to boulders of several meters of diameter. For geoscientists it is important to predict possible triggering zones and deposition areas or run out lengths. Run out analysis is an especially important component for hazard assessment in alpine watersheds, which includes prediction of potential hazard areas and mapping the distribution of hazard intensity parameters such as the thickness of the deposit. In this study terrestrial laser scanning has been applied to investigate the spatial distribution of erosion and deposition of bed load material over a 4000 m long reach of a torrent. Within the monitoring period a new open check dam was built at the study site after removing the old one. Due to the open construction it was expected, that during flood events sediment is stored behind the check dam, but during smaller flood events the deposition area should be self-emptied again. The measurements were carried out to investigate if the new check dam functioned as expected. Therefore the reach has been scanned 6 times during the last 3 years. Several monitoring activities before and after torrent events required global data registration using differential GPS. Tachymetry connected areas with missing GPS reception to GPS measured ones. Terrestrial laser scanning provided dense 3d-data. The RIEGL LMS-Z420i was chosen due to its long range, high accuracy and high scanning speed of the measurements. The accuracy of the measurement was in a range of 8 cm. The objectives of the TLS survey of the torrent deposit were to determine the volume of the deposited mass as well as to detect zones of erosion and deposition of material by the creation of high resolution DEM's. The results of the measurements taken at the test site in Carinthia, Austria are

  7. Digital Terrain Models from Mobile Laser Scanning Data in Moravian Karst

    NASA Astrophysics Data System (ADS)

    Tyagur, N.; Hollaus, M.

    2016-06-01

    During the last ten years, mobile laser scanning (MLS) systems have become a very popular and efficient technology for capturing reality in 3D. A 3D laser scanner mounted on the top of a moving vehicle (e.g. car) allows the high precision capturing of the environment in a fast way. Mostly this technology is used in cities for capturing roads and buildings facades to create 3D city models. In our work, we used an MLS system in Moravian Karst, which is a protected nature reserve in the Eastern Part of the Czech Republic, with a steep rocky terrain covered by forests. For the 3D data collection, the Riegl VMX 450, mounted on a car, was used with integrated IMU/GNSS equipment, which provides low noise, rich and very dense 3D point clouds. The aim of this work is to create a digital terrain model (DTM) from several MLS data sets acquired in the neighbourhood of a road. The total length of two covered areas is 3.9 and 6.1 km respectively, with an average width of 100 m. For the DTM generation, a fully automatic, robust, hierarchic approach was applied. The derivation of the DTM is based on combinations of hierarchical interpolation and robust filtering for different resolution levels. For the generation of the final DTMs, different interpolation algorithms are applied to the classified terrain points. The used parameters were determined by explorative analysis. All MLS data sets were processed with one parameter set. As a result, a high precise DTM was derived with high spatial resolution of 0.25 x 0.25 m. The quality of the DTMs was checked by geodetic measurements and visual comparison with raw point clouds. The high quality of the derived DTM can be used for analysing terrain changes and morphological structures. Finally, the derived DTM was compared with the DTM of the Czech Republic (DMR 4G) with a resolution of 5 x 5 m, which was created from airborne laser scanning data. The vertical accuracy of the derived DTMs is around 0.10 m.

  8. Roughness of biopores and cracks in Bt-horizons by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Leue, Martin; Gerke, Horst H.

    2016-04-01

    During preferential flow events in structured soils, the movement of water and reactive solutes is mostly restricted to larger inter-aggregate pores, cracks, and biopores. The micro-topography of such macropores in terms of pore shapes, geometry, and roughness is crucial for describing the exchange of water and solutes between macropores and the soil matrix. The objective of this study was to determine the surface roughness of intact structural surfaces from the Bt-horizon of Luvisols by confocal laser scanning microscopy. For this purpose, samples with the structural surface types including cracks with and without clay-organic coatings from Bt-horizons developed on loess and glacial till were compared. The surface roughness of these structures was calculated in terms of three parameters from selected surface regions of 0.36 mm² determined with a confocal laser scanning microscope of the type Keyence VK-X100K. These data were evaluated in terms of the root-mean-squared roughness, Rq, the curvature, Rku, and the ratio between surface area and base area, RA. Values of Rq and RA were smaller for coated as compared to uncoated cracks and earthworm burrows of the Bt-horizons from both parent materials. The results indicated that the illuviation of clayey material led to a "smoothing" of the crack surfaces, which was similar for the coarser textured till-Bt and the finer-textured loess-Bt surfaces. The roughness indicated by Rq and RA values was only slightly smaller and that indicated by Rku slightly higher for the structural surfaces from the loess as compared to those from the glacial till. These results suggest a minor importance of the parent material on the roughness of structural surfaces in the Bt-horizon. The similarity of Rq, RA, and Rku values between surfaces of earthworm burrows and uncoated cracks did not confirm an expected smoothing effect of the burrow walls by the earthworm. In contrast to burrow walls, root channels from the loess-Bt were smoother

  9. Long-range laser scanning and 3D imaging for the Gneiss quarries survey

    NASA Astrophysics Data System (ADS)

    Schenker, Filippo Luca; Spataro, Alessio; Pozzoni, Maurizio; Ambrosi, Christian; Cannata, Massimiliano; Günther, Felix; Corboud, Federico

    2016-04-01

    In Canton Ticino (Southern Switzerland), the exploitation of natural stone, mostly gneisses, is an important activity of valley's economies. Nowadays, these economic activities are menaced by (i) the exploitation costs related to geological phenomena such as fractures, faults and heterogeneous rocks that hinder the processing of the stone product, (ii) continuously changing demand because of the evolving natural stone fashion and (iii) increasing administrative limits and rules acting to protect the environment. Therefore, the sustainable development of the sector for the next decades needs new and effective strategies to regulate and plan the quarries. A fundamental step in this process is the building of a 3D geological model of the quarries to constrain the volume of commercial natural stone and the volume of waste. In this context, we conducted Terrestrial Laser Scanning surveys of the quarries in the Maggia Valley to obtain a detailed 3D topography onto which the geological units were mapped. The topographic 3D model was obtained with a long-range laser scanning Riegl VZ4000 that can measure from up to 4 km of distance with a speed of 147,000 points per second. It operates with the new V-line technology, which defines the surface relief by sensing differentiated signals (echoes), even in the presence of obstacles such as vegetation. Depending on the esthetics of the gneisses, we defined seven types of natural stones that, together with faults and joints, were mapped onto the 3D models of the exploitation sites. According to the orientation of the geological limits and structures, we projected the different rock units and fractures into the excavation front. This way, we obtained a 3D geological model from which we can quantitatively estimate the volume of the seven different natural stones (with different commercial value) and waste (with low commercial value). To verify the 3D geological models and to quantify exploited rock and waste volumes the same

  10. Diameter distribution estimation with laser scanning based multisource single tree inventory

    NASA Astrophysics Data System (ADS)

    Kankare, Ville; Liang, Xinlian; Vastaranta, Mikko; Yu, Xiaowei; Holopainen, Markus; Hyyppä, Juha

    2015-10-01

    Tree detection and tree species recognition are bottlenecks of the airborne remote sensing-based single tree inventories. The effect of these factors in forest attribute estimation can be reduced if airborne measurements are aided with tree mapping information that is collected from the ground. The main objective here was to demonstrate the use of terrestrial laser scanning-derived (TLS) tree maps in aiding airborne laser scanning-based (ALS) single tree inventory (multisource single tree inventory, MS-STI) and its capability in predicting diameter distribution in various forest conditions. Automatic measurement of TLS point clouds provided the tree maps and the required reference information from the tree attributes. The study area was located in Evo, Finland, and the reference data was acquired from 27 different sample plots with varying forest conditions. The workflow of MS-STI included: (1) creation of automatic tree map from TLS point clouds, (2) automatic diameter at breast height (DBH) measurement from TLS point clouds, (3) individual tree detection (ITD) based on ALS, (4) matching the ITD segments to the field-measured reference, (5) ALS point cloud metric extraction from the single tree segments and (6) DBH estimation based on the derived metrics. MS-STI proved to be accurate and efficient method for DBH estimation and predicting diameter distribution. The overall accuracy (root mean squared error, RMSE) of the DBH was 36.9 mm. Results showed that the DBH accuracy decreased if the tree density (trees/ha) increased. The highest accuracies were found in old-growth forests (tree densities less than 500 stems/ha). MS-STI resulted in the best accuracies regarding Norway spruce (Picea abies (L.) H. Karst.)-dominated forests (RMSE of 29.9 mm). Diameter distributions were predicted with low error indices, thereby resulting in a good fit compared to the reference. Based on the results, diameter distribution estimation with MS-STI is highly dependent on the forest

  11. Co-Registration of DSMs Generated by Uav and Terrestrial Laser Scanning Systems

    NASA Astrophysics Data System (ADS)

    Ancil Persad, Ravi; Armenakis, Costas

    2016-06-01

    An approach for the co-registration of Digital Surface Models (DSMs) derived from Unmanned Aerial Vehicles (UAVs) and Terrestrial Laser Scanners (TLS) is proposed. Specifically, a wavelet-based feature descriptor for matching surface keypoints on the 2.5D DSMs is developed. DSMs are useful in wide-scope of various applications such as 3D building modelling and reconstruction, cultural heritage, urban and environmental planning, aircraft navigation/path routing, accident and crime scene reconstruction, mining as well as, topographic map revision and change detection. For these listed applications, it is not uncommon that there will be a need for automatically aligning multi-temporal DSMs which may have been acquired from multiple sensors, with different specifications over a period of time, and may have various overlaps. Terrestrial laser scanners usually capture urban facades in an accurate manner; however this is not the case for building roof structures. On the other hand, vertical photography from UAVs can capture the roofs. Therefore, the automatic fusion of UAV and laser-scanning based DSMs is addressed here as it serves various geospatial applications.

  12. Characterization of landslide ground surface kinematics from terrestrial laser scanning and strain field computation

    NASA Astrophysics Data System (ADS)

    Teza, Giordano; Pesci, Arianna; Genevois, Rinaldo; Galgaro, Antonio

    2008-05-01

    Assessment and mitigation of the risk induced by landslide activation need an appropriate phenomenon investigation, to obtain useful information about the failure processes. The first step is the complete kinematics characterization of the landslide ground surface, by evaluating the involved displacement and deformation patterns. A dense displacement field can be obtained from comparison of a series of multi-temporal observations performed by means of terrestrial laser scanning. Subsequently, the strain field can be computed from displacement vectors. In this paper, a modified least square technique is employed to compute the strain on the nodes of a regular grid (2D approach) or on the points of a digital terrain model (3D approach). Such a computation takes into account the displacements, their spatial distribution, as well as the measurement and modelling errors. A scale factor is introduced in order to emphasize the contributions of the experimental points on the basis of their distance from each computation point, and to recognize possible scale-depending behaviours. This method has been implemented in Matlab and applied on two landslides located in the northeastern Italian Alps (Lamosano and Perarolo di Cadore). The experiments show that different kinematics can be recognized, and the presence and influence of eventual discontinuities can be revealed.

  13. A dual growing method for the automatic extraction of individual trees from mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Li, Lin; Li, Dalin; Zhu, Haihong; Li, You

    2016-10-01

    Street trees interlaced with other objects in cluttered point clouds of urban scenes inhibit the automatic extraction of individual trees. This paper proposes a method for the automatic extraction of individual trees from mobile laser scanning data, according to the general constitution of trees. Two components of each individual tree - a trunk and a crown can be extracted by the dual growing method. This method consists of coarse classification, through which most of artifacts are removed; the automatic selection of appropriate seeds for individual trees, by which the common manual initial setting is avoided; a dual growing process that separates one tree from others by circumscribing a trunk in an adaptive growing radius and segmenting a crown in constrained growing regions; and a refining process that draws a singular trunk from the interlaced other objects. The method is verified by two datasets with over 98% completeness and over 96% correctness. The low mean absolute percentage errors in capturing the morphological parameters of individual trees indicate that this method can output individual trees with high precision.

  14. Applicability of confocal laser scanning microscopy for evaluation and monitoring of cutaneous wound healing

    NASA Astrophysics Data System (ADS)

    Lange-Asschenfeldt, Susanne; Bob, Adrienne; Terhorst, Dorothea; Ulrich, Martina; Fluhr, Joachim; Mendez, Gil; Roewert-Huber, Hans-Joachim; Stockfleth, Eggert; Lange-Asschenfeldt, Bernhard

    2012-07-01

    There is a high demand for noninvasive imaging techniques for wound assessment. In vivo reflectance confocal laser scanning microscopy (CLSM) represents an innovative optical technique for noninvasive evaluation of normal and diseased skin in vivo at near cellular resolution. This study was designed to test the feasibility of CLSM for noninvasive analysis of cutaneous wound healing in 15 patients (7 male/8 female), including acute and chronic, superficial and deep dermal skin wounds. A commercially available CLSM system was used for the assessment of wound bed and wound margins in order to obtain descriptive cellular and morphological parameters of cutaneous wound repair noninvasively and over time. CLSM was able to visualize features of cutaneous wound repair in epidermal and superficial dermal wounds, including aspects of inflammation, neovascularisation, and tissue remodelling in vivo. Limitations include the lack of mechanic fixation of the optical system on moist surfaces restricting the analysis of chronic skin wounds to the wound margins, as well as a limited optical resolution in areas of significant slough formation. By describing CLSM features of cutaneous inflammation, vascularisation, and epithelialisation, the findings of this study support the role of CLSM in modern wound research and management.

  15. Possibilities of a Personal Laser Scanning System for Forest Mapping and Ecosystem Services

    PubMed Central

    Liang, Xinlian; Kukko, Antero; Kaartinen, Harri; Hyyppä, Juha; Yu, Xiaowei; Jaakkola, Anttoni; Wang, Yunsheng

    2014-01-01

    A professional-quality, personal laser scanning (PLS) system for collecting tree attributes was demonstrated in this paper. The applied system, which is wearable by human operators, consists of a multi-constellation navigation system and an ultra-high-speed phase-shift laser scanner mounted on a rigid baseplate and consisting of a single sensor block. A multipass-corridor-mapping method was developed to process PLS data and a 2,000 m2 forest plot was utilized in the test. The tree stem detection accuracy was 82.6%; the root mean square error (RMSE) of the estimates of tree diameter at breast height (DBH) was 5.06 cm; the RMSE of the estimates of tree location was 0.38 m. The relative RMSE of the DBH estimates was 14.63%. The results showed, for the first time, the potential of the PLS system in mapping large forest plots. Further research on mapping accuracy in various forest conditions, data correction methods and multi-sensoral positioning techniques is needed. The utilization of this system in different applications, such as harvester operations, should also be explored. In addition to collecting tree-level and plot-level data for forest inventory, other possible applications of PLS for forest ecosystem services include mapping of canopy gaps, measuring leaf area index of large areas, documenting and visualizing forest routes feasible for recreation, hiking and berry and mushroom picking. PMID:24434879

  16. In vivo laser scanning microscopic investigation of the decontamination of hazardous substances from the human skin

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Patzelt, A.; Schanzer, S.; Richter, H.; Gross, I.; Menting, K. H.; Frazier, L.; Sterry, W.; Antoniou, C.

    2010-12-01

    The stimulation of the penetration of topically applied substances into the skin is a topic of intensive dermatological and pharmacological research. In this context, it was found that in addition to the intercellular penetration, the follicular penetration also represents an efficient penetration pathway. The hair follicles act as a long-term reservoir for topically applied substances. They are surrounded by all important target structures, such as blood capillaries, stem and dendritic cells. Therefore, the hair follicles, as well as the skin, need to be protected from hazardous substances. The traditional method of decontamination after respective accidental contacts consists of an intensive washing of the skin. However, during this mechanical procedure, the substances can be pushed even deeper into the hair follicles. In the present study, absorbent materials were applied to remove a fluorescent model substance from the skin without inducing mechanical stress. The results were compared to the decontamination effects obtained by intensive washing. Investigations were performed by means of in vivo laser scanning microscopy (LSM). The comparison revealed that decontamination with absorbent materials is more effective than decontamination with washing processes.

  17. Monitoring of Fluvial Transport in the Mountain River Bed Using Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Jozkow, G.; Borkowski, A.; Kasprzak, M.

    2016-06-01

    The fluvial transport is the surface process that has a strong impact on the topography changes, especially in mountain areas. Traditional hydrological measurements usually give a good understanding of the river flow, however, the information of the bedload movement in the rivers is still insufficient. In particular, there is limited knowledge about the movement of the largest clasts, i.e. boulders. This investigation addresses mentioned issues by employing Terrestrial Laser Scanning (TLS) to monitor annual changes of the mountain river bed. The vertical changes were estimated based on the Digital Elevation Model (DEM) of difference (DoD) while transported boulders were identified based on the distances between point clouds and RGB-coloured points. Combined RGB point clouds allowed also to measure 3D displacements of boulders. The results showed that the highest dynamic of the fluvial process occurred between years 2012-2013. Obtained DoD clearly indicated alternating zones of erosion and deposition of the sediment finer fractions in the local sedimentary traps. The horizontal displacement of the rock material in the river bed showed high complexity resulting in the displacement of large boulders (major axis about 0.8 m) for the distance up to 2.3 m.

  18. Quantifying vegetation and geomorphic patterns within nebkha dune fields using terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Nield, Joanna; Gillies, John; Nickling, William

    2014-05-01

    Vegetation and sand in semi-arid and coastal sediment starved environments typically interact and form nebkha dunes. We examine the typical dune and vegetation patterns that form with varying amounts of sediment availability and nebkha maturity at Jornada in the Chihuahuan Desert, New Mexico, USA using terrestrial laser scanning (TLS) to separate the plant and sand elements. Manual and automated TLS shrub height extractions compare well at all sites (p=0.48-0.94) enabling the quantification of both solid and plant roughness element components. We find that there is a switch in orientation of the dune elements with respect to dominant wind direction from perpendicular to parallel as the landscape develops from an incipient to mature configuration and mesquite-nebkha streets are enhanced. As the nebkha dunes develop the surface coverage of bare sand increases and dune surfaces exceed the size of their companion shrubs. Roughness density also increases at the mature dune site. Over a three year period up to 20cm of erosion was measured on the upwind faces of the mature nebkha dunes, in agreement with the dominant annual wind direction. However, deposition patterns were more diffuse and influenced by the vegetation patterns. TLS is a useful tool for examining complex sand-vegetation interactions and dune field development.

  19. Combined use of terrestrial laser scanning and IR thermography applied to a historical building.

    PubMed

    Costanzo, Antonio; Minasi, Mario; Casula, Giuseppe; Musacchio, Massimo; Buongiorno, Maria Fabrizia

    2014-12-24

    The conservation of architectural heritage usually requires a multidisciplinary approach involving a variety of specialist expertise and techniques. Nevertheless, destructive techniques should be avoided, wherever possible, in order to preserve the integrity of the historical buildings, therefore the development of non-destructive and non-contact techniques is extremely important. In this framework, a methodology for combining the terrestrial laser scanning and the infrared thermal images is proposed, in order to obtain a reconnaissance of the conservation state of a historical building. The proposed case study is represented by St. Augustine Monumental Compound, located in the historical centre of the town of Cosenza (Calabria, South Italy). Adopting the proposed methodology, the paper illustrates the main results obtained for the building test overlaying and comparing the collected data with both techniques, in order to outline the capabilities both to detect the anomalies and to improve the knowledge on health state of the masonry building. The 3D model, also, allows to provide a reference model, laying the groundwork for implementation of a monitoring multisensor system based on the use of non-destructive techniques.

  20. Performance analysis of freeware filtering algorithms for determining ground surface from airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Julge, Kalev; Ellmann, Artu; Gruno, Anti

    2014-01-01

    Numerous filtering algorithms have been developed in order to distinguish the ground surface from nonground points acquired by airborne laser scanning. These algorithms automatically attempt to determine the ground points using various features such as predefined parameters and statistical analysis. Their efficiency also depends on landscape characteristics. The aim of this contribution is to test the performance of six common filtering algorithms embedded in three freeware programs. The algorithms' adaptive TIN, elevation threshold with expand window, maximum local slope, progressive morphology, multiscale curvature, and linear prediction were tested on four relatively large (4 to 8 km2) and diverse landscape areas, which included steep sloped hills, urban areas, ridge-like eskers, and a river valley. The results show that in diverse test areas each algorithm yields various commission and omission errors. It appears that adaptive TIN is suitable in urban areas while the multiscale curvature algorithm is best suited in wooded areas. The multiscale curvature algorithm yielded the overall best results with average root-mean-square error values of 0.35 m.

  1. Quantitative characterization of the surface topography of rolled sheets by laser scanning microscopy and fourier transformation

    NASA Astrophysics Data System (ADS)

    Gjønnes, Liv

    1996-08-01

    The surface of twin-roll cast aluminum sheets undergoes dramatic changes during cold rolling. This is mainly due to variables in the roll gap, topography of the rolls, lubrication, material properties, and in particular the initial structure and topography of the cast sheet. Therefore, it is important to have means to quantitatively describe the changes in the surface structure of each pass and from pass to pass in order to optimize the desired final surface structure. To achieve this, the laser scanning microscope (LSM) with its confocal technique has been employed to image the three-dimensional (3-D) topography and to digitize the image for further computer analysis. The digitization of the image is primarily motivated by the need to introduce a Fourier transformation of the surface topography. The method is effective in describing qualitative periodic trends in the surface features. Information is gained on the shape and periodicities as well as roughness directionality. For instance, grooves and cross hatches and their remnants can be followed from one pass to the other. Important characteristics of the surface topography such as rolling ridges and shingles can also easily be characterized.

  2. Use of Naturally Available Reference Targets to Calibrate Airborne Laser Scanning Intensity Data

    PubMed Central

    Vain, Ants; Kaasalainen, Sanna; Pyysalo, Ulla; Krooks, Anssi; Litkey, Paula

    2009-01-01

    We have studied the possibility of calibrating airborne laser scanning (ALS) intensity data, using land targets typically available in urban areas. For this purpose, a test area around Espoonlahti Harbor, Espoo, Finland, for which a long time series of ALS campaigns is available, was selected. Different target samples (beach sand, concrete, asphalt, different types of gravel) were collected and measured in the laboratory. Using tarps, which have certain backscattering properties, the natural samples were calibrated and studied, taking into account the atmospheric effect, incidence angle and flying height. Using data from different flights and altitudes, a time series for the natural samples was generated. Studying the stability of the samples, we could obtain information on the most ideal types of natural targets for ALS radiometric calibration. Using the selected natural samples as reference, the ALS points of typical land targets were calibrated again and examined. Results showed the need for more accurate ground reference data, before using natural samples in ALS intensity data calibration. Also, the NIR camera-based field system was used for collecting ground reference data. This system proved to be a good means for collecting in situ reference data, especially for targets with inhomogeneous surface reflection properties. PMID:22574045

  3. a Feasibility Study on Use of Generic Mobile Laser Scanning System for Detecting Asphalt Pavement Cracks

    NASA Astrophysics Data System (ADS)

    Chen, Xinqu; Li, Jonathan

    2016-06-01

    This study aims to automatically detect pavement cracks on urban roads by employing the 3D point clouds acquired by a mobile laser scanning (MLS) system. Our method consists of four steps: ground point filtering, high-pass convolution, matched filtering, and noise removal. First, a voxel-based upward growing method is applied to construct Digital Terrain Model (DTM) of the road surface. Then, a high-pass filter convolutes the DTM to detect local elevation changes that may embed cracking information. Next, a two-step matched filter is applied to extract crack features. Lastly, a noise removal process is conducted to refine the results. Instead of using MLS intensity, this study takes advantages of the MLS elevation information to perform automated crack detection from large-volume, mixed-density, unstructured MLS point clouds. Four types of cracks including longitudinal, transvers, random, and alligator cracks are detected. Our results demonstrated that the proposed method works well with the RIEGL VMX-450 point clouds and can detect cracks in moderate-to-severe severity (13 - 25 mm) within a 200 m by 30 m urban road segment located in Kingston, Ontario, at one time. Due to the resolution capability, small cracks with slight severity remain unclear in the MLS point cloud.

  4. Automated Analysis of Barley Organs Using 3D Laser Scanning: An Approach for High Throughput Phenotyping

    PubMed Central

    Paulus, Stefan; Dupuis, Jan; Riedel, Sebastian; Kuhlmann, Heiner

    2014-01-01

    Due to the rise of laser scanning the 3D geometry of plant architecture is easy to acquire. Nevertheless, an automated interpretation and, finally, the segmentation into functional groups are still difficult to achieve. Two barley plants were scanned in a time course, and the organs were separated by applying a histogram-based classification algorithm. The leaf organs were represented by meshing algorithms, while the stem organs were parameterized by a least-squares cylinder approximation. We introduced surface feature histograms with an accuracy of 96% for the separation of the barley organs, leaf and stem. This enables growth monitoring in a time course for barley plants. Its reliability was demonstrated by a comparison with manually fitted parameters with a correlation R2 = 0.99 for the leaf area and R2 = 0.98 for the cumulated stem height. A proof of concept has been given for its applicability for the detection of water stress in barley, where the extension growth of an irrigated and a non-irrigated plant has been monitored. PMID:25029283

  5. Real time confocal laser scanning microscopy: Potential applications in space medicine and cell biology

    NASA Astrophysics Data System (ADS)

    Rollan, Ana; Ward, Thelma; McHale, Anthony P.

    Photodynamic therapy (PDT), in which tissues may be rendered fatally light-sensitive represents a relatively novel treatment for cancer and other disorders such as cardiovascular disease. It offers significant application to disease control in an isolated environment such as space flight. In studying PDT in the laboratory, low energy lasers such as HeNe lasers are used to activate the photosensitized cellular target. A major problem associated with these studies is that events occurring during actual exposure of the target cells to the system cannot be examined in real time. In this study HeLa cells were photosensitized and photodynamic activation was accomplished using the scanning microbeam from a confocal laser scanning microscope. This form of activation allowed for simultaneous photoactivation and observation and facilitated the recording of events at a microscopic level during photoactivation. Effects of photodynamic activation on the target cells were monitored using the fluorophores rhodamine 123 and ethidium homodimer-1. Potential applications of these forms of analyses to space medicine and cell biology are discussed.

  6. Roof Reconstruction from Airborne Laser Scanning Data Based on Image Processing Methods

    NASA Astrophysics Data System (ADS)

    Goebbels, S.; Pohle-Fröhlich, R.

    2016-06-01

    The paper presents a new data-driven approach to generate CityGML building models from airborne laser scanning data. The approach is based on image processing methods applied to an interpolated height map and avoids shortcomings of established methods for plane detection like Hough transform or RANSAC algorithms on point clouds. The improvement originates in an interpolation algorithm that generates a height map from sparse point cloud data by preserving ridge lines and step edges of roofs. Roof planes then are detected by clustering the height map's gradient angles, parameterizations of planes are estimated and used to filter out noise around ridge lines. On that basis, a raster representation of roof facets is generated. Then roof polygons are determined from region outlines, connected to a roof boundary graph, and simplified. Whereas the method is not limited to churches, the method's performance is primarily tested for church roofs of the German city of Krefeld because of their complexity. To eliminate inaccuracies of spires, contours of towers are detected additionally, and spires are rendered as solids of revolution. In our experiments, the new data-driven method lead to significantly better building models than the previously applied model-driven approach.

  7. Confocal laser-scanning microscopy of capillaries in normal and psoriatic skin

    NASA Astrophysics Data System (ADS)

    Archid, Rami; Patzelt, Alexa; Lange-Asschenfeldt, Bernhard; Ahmad, Sufian S.; Ulrich, Martina; Stockfleth, Eggert; Philipp, Sandra; Sterry, Wolfram; Lademann, Juergen

    2012-10-01

    An important and most likely active role in the pathogenesis of psoriasis has been attributed to changes in cutaneous blood vessels. The purpose of this study was to use confocal laser-scanning microscopy (CLSM) to investigate dermal capillaries in psoriatic and normal skin. The structures of the capillary loops in 5 healthy participants were compared with those in affected skin of 13 psoriasis patients. The diameters of the capillaries and papillae were measured for each group with CLSM. All investigated psoriasis patients showed elongated, widened, and tortuous microvessels in the papillary dermis, whereas all healthy controls showed a single capillary loop in each dermal papilla. The capillaries of the papillary loop and the dermal papilla were significantly enlarged in the psoriatic skin lesions (diameters 24.39±2.34 and 146.46±28.52 μm, respectively) in comparison to healthy skin (diameters 9.53±1.8 and 69.48±17.16 μm, respectively) (P<0.001). CLSM appears to represent a promising noninvasive technique for evaluating dermal capillaries in patients with psoriasis. The diameter of the vessels could be seen as a well-quantifiable indicator for the state of psoriatic skin. CLSM could be useful for therapeutic monitoring to delay possible recurrences.

  8. A novel near real-time laser scanning device for geometrical determination of pleural cavity surface

    NASA Astrophysics Data System (ADS)

    Kim, Michele M.; Zhu, Timothy C.

    2013-03-01

    During HPPH-mediated pleural photodynamic therapy (PDT), it is critical to determine the anatomic geometry of the pleural surface quickly as there may be movement during treatment resulting in changes with the cavity. We have developed a laser scanning device for this purpose, which has the potential to obtain the surface geometry in real-time. A red diode laser with a holographic template to create a pattern and a camera with auto-focusing abilities are used to scan the cavity. In conjunction with a calibration with a known surface, we can use methods of triangulation to reconstruct the surface. Using a chest phantom, we are able to obtain a 360 degree scan of the interior in under 1 minute. The chest phantom scan was compared to an existing CT scan to determine its accuracy. The laser-camera separation can be determined through the calibration with 2mm accuracy. The device is best suited for environments that are on the scale of a chest cavity (between 10cm and 40cm). This technique has the potential to produce cavity geometry in real-time during treatment. This would enable PDT treatment dosage to be determined with greater accuracy. Works are ongoing to build a miniaturized device that moves the light source and camera via a fiber-optics bundle commonly used for endoscopy with increased accuracy.

  9. Use of naturally available reference targets to calibrate airborne laser scanning intensity data.

    PubMed

    Vain, Ants; Kaasalainen, Sanna; Pyysalo, Ulla; Krooks, Anssi; Litkey, Paula

    2009-01-01

    We have studied the possibility of calibrating airborne laser scanning (ALS) intensity data, using land targets typically available in urban areas. For this purpose, a test area around Espoonlahti Harbor, Espoo, Finland, for which a long time series of ALS campaigns is available, was selected. Different target samples (beach sand, concrete, asphalt, different types of gravel) were collected and measured in the laboratory. Using tarps, which have certain backscattering properties, the natural samples were calibrated and studied, taking into account the atmospheric effect, incidence angle and flying height. Using data from different flights and altitudes, a time series for the natural samples was generated. Studying the stability of the samples, we could obtain information on the most ideal types of natural targets for ALS radiometric calibration. Using the selected natural samples as reference, the ALS points of typical land targets were calibrated again and examined. Results showed the need for more accurate ground reference data, before using natural samples in ALS intensity data calibration. Also, the NIR camera-based field system was used for collecting ground reference data. This system proved to be a good means for collecting in situ reference data, especially for targets with inhomogeneous surface reflection properties.

  10. In Vivo Laser Scanning Confocal Microscopy of Human Meibomian Glands in Aging and Ocular Surface Diseases.

    PubMed

    Fasanella, Vincenzo; Agnifili, Luca; Mastropasqua, Rodolfo; Brescia, Lorenza; Di Staso, Federico; Ciancaglini, Marco; Mastropasqua, Leonardo

    2016-01-01

    Meibomian glands (MGs) play a crucial role in the ocular surface homeostasis by providing lipids to the superficial tear film. Their dysfunction destabilizes the tear film leading to a progressive loss of the ocular surface equilibrium and increasing the risk for dry eye. In fact, nowadays, the meibomian gland dysfunction is one of the leading causes of dry eye. Over the past decades, MGs have been mainly studied by using meibography, which, however, cannot image the glandular structure at a cellular level. The diffusion of the in vivo laser scanning confocal microscopy (LSCM) provided a new approach for the structural assessment of MGs permitting a major step in the noninvasive evaluation of these structures. LSCM is capable of showing MGs modifications during aging and in the most diffuse ocular surface diseases such as dry eye, allergy, and autoimmune conditions and in the drug-induced ocular surface disease. On the other hand, LSCM may help clinicians in monitoring the tissue response to therapy. In this review, we summarized the current knowledge about the role of in vivo LSCM in the assessment of MGs during aging and in the most diffuse ocular surface diseases.

  11. Integrating optical satellite data and airborne laser scanning in habitat classification for wildlife management

    NASA Astrophysics Data System (ADS)

    Nijland, W.; Coops, N. C.; Nielsen, S. E.; Stenhouse, G.

    2015-06-01

    Wildlife habitat selection is determined by a wide range of factors including food availability, shelter, security and landscape heterogeneity all of which are closely related to the more readily mapped landcover types and disturbance regimes. Regional wildlife habitat studies often used moderate resolution multispectral satellite imagery for wall to wall mapping, because it offers a favourable mix of availability, cost and resolution. However, certain habitat characteristics such as canopy structure and topographic factors are not well discriminated with these passive, optical datasets. Airborne laser scanning (ALS) provides highly accurate three dimensional data on canopy structure and the underlying terrain, thereby offers significant enhancements to wildlife habitat mapping. In this paper, we introduce an approach to integrate ALS data and multispectral images to develop a new heuristic wildlife habitat classifier for western Alberta. Our method combines ALS direct measures of canopy height, and cover with optical estimates of species (conifer vs. deciduous) composition into a decision tree classifier for habitat - or landcover types. We believe this new approach is highly versatile and transferable, because class rules can be easily adapted for other species or functional groups. We discuss the implications of increased ALS availability for habitat mapping and wildlife management and provide recommendations for integrating multispectral and ALS data into wildlife management.

  12. Multi-frequency AOM for multi-beam laser scanning exposure system

    NASA Astrophysics Data System (ADS)

    Shinada, Hidetoshi

    2016-10-01

    Digital printing systems recorded on films or computer to plates (CTPs) have been required to improve their productivity and image quality. Under the circumstance, a printing technology of the multi-beam laser scanning for the drum capstan system, which is almost the same as optics configuration as the flat bed system, was developed using a newly developed multi-frequency acousto-optic modulator (AOM) as a key device instead of ultra-fast scanning devices toward a main scan direction. The multi-frequency AOM was developed with phased array-type transducers, achieving a wider bandwidth of over 160 MHz. The design consisted of a simultaneous three beams generation with interlace scan to avoid the beat effect by adjacent Doppler-shifted beams, which consequently attained the fastest recording speed of 5.0 mm/s compared with 2.0-3.0 mm/s of existing systems in those days. Furthermore, a couple of critical parameters of the multi-frequency AOM are studied, for example, a treatment of third-order intermodulation and also beat effect in connection with photosensitive media. As a result, the necessity of interlaces scanning to obtain good image quality without beat effect and also to allow a lower laser power to apply is proposed.

  13. Automatic Registration of Terrestrial Laser Scanning Point Clouds using Panoramic Reflectance Images.

    PubMed

    Kang, Zhizhong; Li, Jonathan; Zhang, Liqiang; Zhao, Qile; Zlatanova, Sisi

    2009-01-01

    This paper presents a new approach to the automatic registration of terrestrial laser scanning (TLS) point clouds using panoramic reflectance images. The approach follows a two-step procedure that includes both pair-wise registration and global registration. The pair-wise registration consists of image matching (pixel-to-pixel correspondence) and point cloud registration (point-to-point correspondence), as the correspondence between the image and the point cloud (pixel-to-point) is inherent to the reflectance images. False correspondences are removed by a geometric invariance check. The pixel-to-point correspondence and the computation of the rigid transformation parameters (RTPs) are integrated into an iterative process that allows for the pair-wise registration to be optimised. The global registration of all point clouds is obtained by a bundle adjustment using a circular self-closure constraint. Our approach is tested with both indoor and outdoor scenes acquired by a FARO LS 880 laser scanner with an angular resolution of 0.036° and 0.045°, respectively. The results show that the pair-wise and global registration accuracies are of millimetre and centimetre orders, respectively, and that the process is fully automatic and converges quickly.

  14. 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.

  15. In vivo assessment of the structure of skin microcirculation by reflectance confocal-laser-scanning microscopy

    NASA Astrophysics Data System (ADS)

    Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

    2012-02-01

    One of the major roles of the skin microcirculation is to supply oxygen and nutrition to the surrounding tissue. Regardless of the close relationship between the microcirculation and the surrounding tissue, there are few non-invasive methods that can evaluate both the microcirculation and its surrounding tissue at the same site. We visualized microcapillary plexus structures in human skin using in vivo reflectance confocal-laser-scanning microscopy (CLSM), Vivascope 3000® (Lucid Inc., USA) and Image J software (National Institutes of Health, USA) for video image processing. CLSM is a non-invasive technique that can visualize the internal structure of the skin at the cellular level. In addition to internal morphological information such as the extracellular matrix, our method reveals capillary structures up to the depth of the subpapillary plexus at the same site without the need for additional optical systems. Video images at specific depths of the inner forearm skin were recorded. By creating frame-to-frame difference images from the video images using off-line video image processing, we obtained images that emphasize the brightness depending on changes of intensity coming from the movement of blood cells. Merging images from different depths of the skin elucidates the 3-dimensional fine line-structure of the microcirculation. Overall our results show the feasibility of a non-invasive, high-resolution imaging technique to characterize the skin microcirculation and the surrounding tissue.

  16. Quantification of chemotaxis during pediatric cardiac surgery by flow and laser scanning cytometry

    NASA Astrophysics Data System (ADS)

    Tarnok, Attila; Schmid, Joerg W.; Osmancik, Pavel; Lenz, Dominik; Pipek, Michal; Hambsch, Joerg; Gerstner, Andreas O.; Schneider, Peter

    2002-05-01

    Cardiac surgery with cardiopulmonary bypass (CPB) alters the leukocyte composition of the peripheral blood (PB). This response contributes to the sometimes adverse outcome with capillary leakage. Migration of activated cells to sites of inflammation, driven by chemokines is part of this response. In order to determine the chemotactic activity of patients serum during and after surgery we established an assay for PB leukocytes (PBL). PBL from healthy donors were isolated and 250,000 cells were placed into a migration chamber separated by a filter from a second lower chamber filled with patient serum. After incubation cells from top and bottom chamber were removed and stained with a cocktail of monoclonal antibodies for leukocyte subsets and analyzed on a flow cytometer (FCM). Cells at the bottom of the filter belong to the migrating compartment and were quantified by LSC after staining of nucleated cells. Increased chemotactic activity started at onset of anaesthesia followed by a phase of low activity immediately after surgery and a second phase of a high post-operative activity. The in vitro results correlated with results obtained by immunopenotyping of circulating PBL. Manipulation of the chemokine pattern might prove beneficial to prevent extravasation of cells leading to tissue damage. In chemotaxis assays with low amount of available serum the combined use of FCM and Laser Scanning LSC proved as an appropriate analytical tool.

  17. Grammar-based Automatic 3D Model Reconstruction from Terrestrial Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Yu, Q.; Helmholz, P.; Belton, D.; West, G.

    2014-04-01

    The automatic reconstruction of 3D buildings has been an important research topic during the last years. In this paper, a novel method is proposed to automatically reconstruct the 3D building models from segmented data based on pre-defined formal grammar and rules. Such segmented data can be extracted e.g. from terrestrial or mobile laser scanning devices. Two steps are considered in detail. The first step is to transform the segmented data into 3D shapes, for instance using the DXF (Drawing Exchange Format) format which is a CAD data file format used for data interchange between AutoCAD and other program. Second, we develop a formal grammar to describe the building model structure and integrate the pre-defined grammars into the reconstruction process. Depending on the different segmented data, the selected grammar and rules are applied to drive the reconstruction process in an automatic manner. Compared with other existing approaches, our proposed method allows the model reconstruction directly from 3D shapes and takes the whole building into account.

  18. Elastomeric photo-actuators and their investigation by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Czaniková, Klaudia; Ilčíková, Markéta; Krupa, Igor; Mičušík, Matej; Kasák, Peter; Pavlova, Ewa; Mosnáček, Jaroslav; Chorvát, Dušan, Jr.; Omastová, Mária

    2013-10-01

    The photo-actuation behavior of nanocomposites based on ethylene-vinylacetate copolymer (EVA) and styrene-isoprene-styrene (SIS) block copolymer filled with well-dispersed and modified multiwalled carbon nanotubes (MWCNTs) is discussed in this paper. The nanocomposites were prepared by casting from solution. To improve the dispersion of the MWCNTs in EVA, the MWCNT surface was modified with a non-covalent surfactant, cholesteryl 1-pyrenecarboxylate (PyChol). To prepare SIS nanocomposites, the MWCNT surface was covalently modified with polystyrene chains. The good dispersion of the filler was confirmed by transmission electron microscopy (TEM). Special, custom-made punch/die molds were used to create a Braille element (BE)-like shape, which under shear forces induces a uniaxial orientation of the MWCNTs within the matrix. The uniaxial orientation of MWCNTs is an essential precondition to ensure the photo-actuating behavior of MWCNTs in polymeric matrices. The orientation of the MWCNTs within the matrices was examined by scanning electron microscopy (SEM). Nanocomposite BEs were illuminated from the bottom by a red light-emitting diode (LED), and the photo-actuation was investigated by confocal laser scanning microscopy (CLSM). When the BEs were exposed to light, a temporary increase in the height of the element was detected. This process was observed to be reversible: after switching off the light, the BEs returned to their original shape and height.

  19. Laser scanning confocal microscopy and laser tweezers based experiments to understand dentine-bacteria interactions

    NASA Astrophysics Data System (ADS)

    Peng, Sum Chee; Mohanty, Samarendra; Gupta, P. K.; Kishen, Anil

    2007-02-01

    Failure of endodontic treatment is commonly due to Enterococcal infection. In this study influence of chemical treatments of type-I collagen membrane by chemical agents commonly used in endodontic treatment on Enterococcus faecalis cell adherence was evaluated. In order to determine the change in number of adhering bacteria after chemical treatment, confocal laser scanning microscopy was used. For this, overnight culture of E faecalis in All Culture broth was applied to chemically treated type-I collagen membrane. It was found that Ca(OH) II treated groups had statistically significant (p value=0.05) increase in population of bacteria adherence. The change in adhesion force between bacteria and collagen was determined by using optical tweezers (1064 nm). For this experiment, Type-I collagen membrane was soaked for 5 mins in a media that contained 50% all culture media and 50% saturated Ca(OH) II . The membrane was spread on the coverslip, on which diluted bacterial suspension was added. The force of laser tweezers on the bacteria was estimated at different trap power levels using viscous drag method and trapping stiffness was calculated using Equipartition theorem method. Presence of Ca(OH) II was found to increase the cell-substrate adherence force from 0.38pN to >2.1pN. Together, these experiments show that it was highly probable that the increase in adherence to collagen was due to a stronger adhesion in the presence of Ca (OH) II.

  20. 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.

  1. Assessing and modeling moose (Alces alces) habitats with airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Melin, M.; Packalén, P.; Matala, J.; Mehtätalo, L.; Pusenius, J.

    2013-08-01

    In the analysis of forest resources, the use of ALS (airborne laser scanning) enables detailed three dimensional (3D) descriptions of forests and their vegetation. Simultaneously, ecologists have recognized that 3D information on vegetation is highly important in analyzing the habitat suitability of a given site. Recently, animals’ habitat preferences have been analyzed, for example, with GPS-collared animals. This has resulted in detailed knowledge about the animals’ movements both spatially and temporally. This study combines 3D information on vegetation obtained from ALS data with information about animal locations from GPS data. The aim was to map and analyze the habitat preferences of moose. The study area was located on the west coast of Finland. The data consisted of 18 GPS-collared moose (monitored from 2009 to 2010) and ALS data collected in 2010. We investigated how habitat structure changes as a function of distance to observed moose locations and how observed moose locations differ from randomly selected locations in terms of 3D structure. We also created a model-based habitat suitability map and tested it against moose occurrences. The results suggested that there are clear differences between the areas occupied and not occupied by moose and that these differences can be detected from ALS data. More importantly, ALS proved its potential in linking 3D descriptions of vegetation directly to observed moose locations without any proxy variables. These observations strongly support future studies.

  2. Three-dimensional assessment of bone turnover using computed microtomography and laser-scanning confocal microscopy

    NASA Astrophysics Data System (ADS)

    Prevrhal, Sven; Jiang, Yebin; Zhao, Jenny; Genant, Harry K.

    2000-06-01

    Objective: Metabolic activity in trabecular bone is an important indicator in the therapy of bone diseases like osteoporosis. It is reflected by the amount of osteoid (young, not yet mineralized bone) and young calcified tissue (YCT). Our aim was to replace standard 2D histomorphometry with a 3D approach for osteoid and YCT measurement. Measurement Methods: Excised lumbar vertebrae of 5 ovariectomized (OVX) and 5 control rats were 3D-scanned with computed micro-tomography ((mu) CT, isotropic spatial resolution 20 micrometer3) and laser scanning confocal microscopy (LSCM, 20X magnification, 1X1X2 micrometer3 spatial resolution). (mu) CT shows trabecular bone structure; LSCM shows osteoid and YCT by fluorescent light. Image Processing Methods: The fraction of bone to tissue volume (BV/TV) and the number of trabeculae (Tb.N) were calculated from globally thresholded (mu) CT images. LSCM images were enhanced using top-hat transform, globally thresholded and morphologically closed. Separate regions were labeled by volume growing. We measured feature volume to background volume ratio and number of features per unit volume. Results and Conclusions: In the specimens obtained from the OVX rats, a significant increase in the volume fractions of osteoid and YCT could be seen. The (mu) CT-LSCM approach presents a significant improvement over time-consuming, standard histomorphometry. The image processing for both modalities could be achieved automatically.

  3. Enamel erosion and prevention efficacy characterized by confocal laser scanning microscope.

    PubMed

    Maia, Ana Marly Araújo; Longbottom, Christopher; Gomes, Anderson Stevens Leonidas; Girkin, John Michael

    2014-06-01

    The aim of this study was to evaluate the erosion-inhibiting effect of two toothpastes on the development of erosion-like lesions, by a confocal laser scanning microscope (CLSM). Forty human enamel blocks were divided into five groups (n = 8), in accordance to evaluate the GC MI Paste Plus and Oral B with stannous fluoride, applied as slurries and associated with toothbrush. Specimens were submitted to an erosion challenge from citric acid (0.5%, pH = 2.8), for 5 min, six times a day, alternating in artificial saliva immersions. Reference group was not exposed to treatment. Part of specimens (Groups 02 and 03) was exposed twice daily just to slurries, for 2 min, therefore specimens from Groups 04 and 05 were also abraded, for 30 s. The enamel surfaces were morphological characterized using CLSM images, with mineral loss being measured using the resulting 3D images referenced to an un-challenged portion of the sample. Step values were compared using the one-way ANOVA test. CLSM was shown to be a viable, noncontact, and simple technique to characterize eroded surfaces. The statistical difference in the step size was significant between the groups (P = 0.001) and using multiple comparisons a statistically significant protective effect of toothpastes was shown when these were applied as slurries. Although groups submitted to tooth brush showed mineral loss similar to reference control group, due to the damages of abrasion associated.

  4. Landslides Identification Using Airborne Laser Scanning Data Derived Topographic Terrain Attributes and Support Vector Machine Classification

    NASA Astrophysics Data System (ADS)

    Pawłuszek, Kamila; Borkowski, Andrzej

    2016-06-01

    Since the availability of high-resolution Airborne Laser Scanning (ALS) data, substantial progress in geomorphological research, especially in landslide analysis, has been carried out. First and second order derivatives of Digital Terrain Model (DTM) have become a popular and powerful tool in landslide inventory mapping. Nevertheless, an automatic landslide mapping based on sophisticated classifiers including Support Vector Machine (SVM), Artificial Neural Network or Random Forests is often computationally time consuming. The objective of this research is to deeply explore topographic information provided by ALS data and overcome computational time limitation. For this reason, an extended set of topographic features and the Principal Component Analysis (PCA) were used to reduce redundant information. The proposed novel approach was tested on a susceptible area affected by more than 50 landslides located on Rożnów Lake in Carpathian Mountains, Poland. The initial seven PCA components with 90% of the total variability in the original topographic attributes were used for SVM classification. Comparing results with landslide inventory map, the average user's accuracy (UA), producer's accuracy (PA), and overall accuracy (OA) were calculated for two models according to the classification results. Thereby, for the PCA-feature-reduced model UA, PA, and OA were found to be 72%, 76%, and 72%, respectively. Similarly, UA, PA, and OA in the non-reduced original topographic model, was 74%, 77% and 74%, respectively. Using the initial seven PCA components instead of the twenty original topographic attributes does not significantly change identification accuracy but reduce computational time.

  5. In Vivo Laser Scanning Confocal Microscopy of Human Meibomian Glands in Aging and Ocular Surface Diseases.

    PubMed

    Fasanella, Vincenzo; Agnifili, Luca; Mastropasqua, Rodolfo; Brescia, Lorenza; Di Staso, Federico; Ciancaglini, Marco; Mastropasqua, Leonardo

    2016-01-01

    Meibomian glands (MGs) play a crucial role in the ocular surface homeostasis by providing lipids to the superficial tear film. Their dysfunction destabilizes the tear film leading to a progressive loss of the ocular surface equilibrium and increasing the risk for dry eye. In fact, nowadays, the meibomian gland dysfunction is one of the leading causes of dry eye. Over the past decades, MGs have been mainly studied by using meibography, which, however, cannot image the glandular structure at a cellular level. The diffusion of the in vivo laser scanning confocal microscopy (LSCM) provided a new approach for the structural assessment of MGs permitting a major step in the noninvasive evaluation of these structures. LSCM is capable of showing MGs modifications during aging and in the most diffuse ocular surface diseases such as dry eye, allergy, and autoimmune conditions and in the drug-induced ocular surface disease. On the other hand, LSCM may help clinicians in monitoring the tissue response to therapy. In this review, we summarized the current knowledge about the role of in vivo LSCM in the assessment of MGs during aging and in the most diffuse ocular surface diseases. PMID:27047965

  6. Revealing the Secrets of Stonehenge Through the Application of Laser Scanning, Photogrammetry and Visualisation Techniques

    NASA Astrophysics Data System (ADS)

    Bryan, P. G.; Abbott, M.; Dodson, A. J.

    2013-07-01

    Stonehenge is perhaps the most famous prehistoric monument in the world. Begun as a simple earthwork enclosure, it was built in several stages with the unique lintelled stone circle being erected in the Neolithic period in around 2,500 BC. Today Stonehenge, together with Avebury and other associated sites, form the heart of a World Heritage Site (WHS) with a unique and dense concentration of outstanding prehistoric monuments. In 2011 English Heritage (EH) embarked on a new survey of the monument. Undertaken by the Greenhatch Group, a commercial survey company based near Derby, a combination of laser scanning and photogrammetric approaches were used to generate the required scale and detailed level of output required by English Heritage. This paper will describe the background to this project and its context within previous survey activities at this World Heritage Site. It will explain the data acquisition technology and processes undertaken on site, the datasets derived from post-processing and their filtering and analysis within both subsequent research projects. Alongside a description of how the data is currently being exploited and proposed future applications within the conservation and management of the site, it will finish by considering the impact of developing geospatial imaging technologies.

  7. Resolution enhancement of digital laser scanning fluorescence microscopy with a dual-lens optical pickup head

    NASA Astrophysics Data System (ADS)

    Tsai, Rung-Ywan; Chen, Jung-Po; Lee, Yuan-Chin; Chiang, Hung-Chih; Huang, Tai-Ting; Huang, Chun-Chieh; Cheng, Chih-Ming; Cheng, Chung-Ta; Lo, Feng-Hsiang; Tiao, Golden

    2016-07-01

    The resolution of the cell fluorescence image captured by a digital laser scanning microscopy with a modified dual-lens BD-ROM optical pickup head is enhanced by image registration and double sample frequency. A dual objective lens of red (655 nm) and blue (405 or 488 nm) laser sources with numerical apertures of 0.6 and 0.85 is used for sample focusing and position tracking and cell fluorescence image capturing, respectively. The image registration and capturing frequency are based on the address-coded patterns of a sample slide. The address-coded patterns are designed as a string of binary code, which comprises a plurality of base-straight lands and grooves and data-straight grooves. The widths of the base-straight lands, base-straight grooves, and data-straight grooves are 0.38, 0.38, and 0.76 μm, respectively. The numbers of sample signals in the x-direction are measured at every intersection point by intersecting the base intensity of the push-pull signal of the address-coded patterns, which has a minimum spacing of 0.38 μm. After taking a double sample frequency, the resolution of the measured cell fluorescence image is enhanced from 0.38 μm to the diffraction limit of the objective lens.

  8. Combined Use of Terrestrial Laser Scanning and IR Thermography Applied to a Historical Building

    PubMed Central

    Costanzo, Antonio; Minasi, Mario; Casula, Giuseppe; Musacchio, Massimo; Buongiorno, Maria Fabrizia

    2015-01-01

    The conservation of architectural heritage usually requires a multidisciplinary approach involving a variety of specialist expertise and techniques. Nevertheless, destructive techniques should be avoided, wherever possible, in order to preserve the integrity of the historical buildings, therefore the development of non-destructive and non-contact techniques is extremely important. In this framework, a methodology for combining the terrestrial laser scanning and the infrared thermal images is proposed, in order to obtain a reconnaissance of the conservation state of a historical building. The proposed case study is represented by St. Augustine Monumental Compound, located in the historical centre of the town of Cosenza (Calabria, South Italy). Adopting the proposed methodology, the paper illustrates the main results obtained for the building test overlaying and comparing the collected data with both techniques, in order to outline the capabilities both to detect the anomalies and to improve the knowledge on health state of the masonry building. The 3D model, also, allows to provide a reference model, laying the groundwork for implementation of a monitoring multisensor system based on the use of non-destructive techniques. PMID:25609042

  9. Inspection of float glass using a novel retroreflective laser scanning system

    NASA Astrophysics Data System (ADS)

    Holmes, Jonathan D.

    1997-07-01

    Since 1988, Image Automation has marketed a float glass inspection system using a novel retro-reflective laser scanning system. The (patented) instrument scans a laser beam by use of a polygon through the glass onto a retro-reflective screen, and collects the retro-reflected light off the polygon, such that a stationary image of the moving spot on the screen is produced. The spot image is then analyzed for optical effects introduced by defects within the glass, which typically distort and attenuate the scanned laser beam, by use of suitable detectors. The inspection system processing provides output of defect size, shape and severity, to the factory network for use in rejection or sorting of glass plates to the end customer. This paper briefly describes the principles of operation, the system architecture, and limitations to sensitivity and measurement repeatability. New instruments based on the retro-reflective scanning method have recently been developed. The principles and implementation are described. They include: (1) Simultaneous detection of defects within the glass and defects in a mirror coating on the glass surface using polarized light. (2) A novel distortion detector for very dark glass. (3) Measurement of optical quality (flatness/refractive homogeneity) of the glass using a position sensitive detector.

  10. High Resolution Airborne Laser Scanning and Hyperspectral Imaging with a Small Uav Platform

    NASA Astrophysics Data System (ADS)

    Gallay, Michal; Eck, Christoph; Zgraggen, Carlo; Kaňuk, Ján; Dvorný, Eduard

    2016-06-01

    The capabilities of unmanned airborne systems (UAS) have become diverse with the recent development of lightweight remote sensing instruments. In this paper, we demonstrate our custom integration of the state-of-the-art technologies within an unmanned aerial platform capable of high-resolution and high-accuracy laser scanning, hyperspectral imaging, and photographic imaging. The technological solution comprises the latest development of a completely autonomous, unmanned helicopter by Aeroscout, the Scout B1-100 UAV helicopter. The helicopter is powered by a gasoline two-stroke engine and it allows for integrating 18 kg of a customized payload unit. The whole system is modular providing flexibility of payload options, which comprises the main advantage of the UAS. The UAS integrates two kinds of payloads which can be altered. Both payloads integrate a GPS/IMU with a dual GPS antenna configuration provided by OXTS for accurate navigation and position measurements during the data acquisition. The first payload comprises a VUX-1 laser scanner by RIEGL and a Sony A6000 E-Mount photo camera. The second payload for hyperspectral scanning integrates a push-broom imager AISA KESTREL 10 by SPECIM. The UAS was designed for research of various aspects of landscape dynamics (landslides, erosion, flooding, or phenology) in high spectral and spatial resolution.

  11. The effect of short ground vegetation on terrestrial laser scans at a local scale

    NASA Astrophysics Data System (ADS)

    Fan, Lei; Powrie, William; Smethurst, Joel; Atkinson, Peter M.; Einstein, Herbert

    2014-09-01

    Terrestrial laser scanning (TLS) can record a large amount of accurate topographical information with a high spatial accuracy over a relatively short period of time. These features suggest it is a useful tool for topographical survey and surface deformation detection. However, the use of TLS to survey a terrain surface is still challenging in the presence of dense ground vegetation. The bare ground surface may not be illuminated due to signal occlusion caused by vegetation. This paper investigates vegetation-induced elevation error in TLS surveys at a local scale and its spatial pattern. An open, relatively flat area vegetated with dense grass was surveyed repeatedly under several scan conditions. A total station was used to establish an accurate representation of the bare ground surface. Local-highest-point and local-lowest-point filters were applied to the point clouds acquired for deriving vegetation height and vegetation-induced elevation error, respectively. The effects of various factors (for example, vegetation height, edge effects, incidence angle, scan resolution and location) on the error caused by vegetation are discussed. The results are of use in the planning and interpretation of TLS surveys of vegetated areas.

  12. Evaluation of Wavelet Denoising Methods for Small-Scale Joint Roughness Estimation Using Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Bitenc, M.; Kieffer, D. S.; Khoshelham, K.

    2015-08-01

    The precision of Terrestrial Laser Scanning (TLS) data depends mainly on the inherent random range error, which hinders extraction of small details from TLS measurements. New post processing algorithms have been developed that reduce or eliminate the noise and therefore enable modelling details at a smaller scale than one would traditionally expect. The aim of this research is to find the optimum denoising method such that the corrected TLS data provides a reliable estimation of small-scale rock joint roughness. Two wavelet-based denoising methods are considered, namely Discrete Wavelet Transform (DWT) and Stationary Wavelet Transform (SWT), in combination with different thresholding procedures. The question is, which technique provides a more accurate roughness estimates considering (i) wavelet transform (SWT or DWT), (ii) thresholding method (fixed-form or penalised low) and (iii) thresholding mode (soft or hard). The performance of denoising methods is tested by two analyses, namely method noise and method sensitivity to noise. The reference data are precise Advanced TOpometric Sensor (ATOS) measurements obtained on 20 × 30 cm rock joint sample, which are for the second analysis corrupted by different levels of noise. With such a controlled noise level experiments it is possible to evaluate the methods' performance for different amounts of noise, which might be present in TLS data. Qualitative visual checks of denoised surfaces and quantitative parameters such as grid height and roughness are considered in a comparative analysis of denoising methods. Results indicate that the preferred method for realistic roughness estimation is DWT with penalised low hard thresholding.

  13. Urban Road Detection in Airbone Laser Scanning Point Cloud Using Random Forest Algorithm

    NASA Astrophysics Data System (ADS)

    Kaczałek, B.; Borkowski, A.

    2016-06-01

    The objective of this research is to detect points that describe a road surface in an unclassified point cloud of the airborne laser scanning (ALS). For this purpose we use the Random Forest learning algorithm. The proposed methodology consists of two stages: preparation of features and supervised point cloud classification. In this approach we consider ALS points, representing only the last echo. For these points RGB, intensity, the normal vectors, their mean values and the standard deviations are provided. Moreover, local and global height variations are taken into account as components of a feature vector. The feature vectors are calculated on a basis of the 3D Delaunay triangulation. The proposed methodology was tested on point clouds with the average point density of 12 pts/m2 that represent large urban scene. The significance level of 15% was set up for a decision tree of the learning algorithm. As a result of the Random Forest classification we received two subsets of ALS points. One of those groups represents points belonging to the road network. After the classification evaluation we achieved from 90% of the overall classification accuracy. Finally, the ALS points representing roads were merged and simplified into road network polylines using morphological operations.

  14. Wide-Area Mapping of Forest with National Airborne Laser Scanning and Field Inventory Datasets

    NASA Astrophysics Data System (ADS)

    Monnet, J.-M.; Ginzler, C.; Clivaz, J.-C.

    2016-06-01

    Airborne laser scanning (ALS) remote sensing data are now available for entire countries such as Switzerland. Methods for the estimation of forest parameters from ALS have been intensively investigated in the past years. However, the implementation of a forest mapping workflow based on available data at a regional level still remains challenging. A case study was implemented in the Canton of Valais (Switzerland). The national ALS dataset and field data of the Swiss National Forest Inventory were used to calibrate estimation models for mean and maximum height, basal area, stem density, mean diameter and stem volume. When stratification was performed based on ALS acquisition settings and geographical criteria, satisfactory prediction models were obtained for volume (R2 = 0.61 with a root mean square error of 47 %) and basal area (respectively 0.51 and 45 %) while height variables had an error lower than 19%. This case study shows that the use of nationwide ALS and field datasets for forest resources mapping is cost efficient, but additional investigations are required to handle the limitations of the input data and optimize the accuracy.

  15. Double-label immunofluorescence with the laser scanning confocal microscope using cyanine dyes.

    PubMed

    Sargent, P B

    1994-11-01

    The laser scanning confocal microscope, when used with the krypton-argon ion laser, is well suited for the simultaneous detection of pairs of antigens by immunofluorescence. Traditionally, double-label studies have utilized secondary antibodies conjugated to fluorescein isothiocyanate (FITC), excited by the 488-nm line (blue), and to tetramethyl rhodamine isothiocyanate or Texas Red, excited by the 568-nm line (yellow). However, the use of fluorophores excited by the 488 nm line produces unsatisfactory results when tissue contains low wavelength-excitable autofluorescence. In the amphibian cardiac ganglion, for example, autofluorescent granules within parasympathetic neurons obscure cell surface-derived signals and prevent one from analyzing the relative position of acetylcholine receptor clusters and synaptic boutons by double-label immunofluorescence. This problem has been solved by using cyanine 3.18 (Cy3)- and cyanine 5.18 (Cy5)-conjugated secondary antibodies, which are excited efficiently by the 568-nm (yellow) and the 647-nm (red) lines and which emit in the orange/red and in the far-red, respectively, and thus by avoiding the 488-nm line altogether. The resulting images are as good or better than those obtained with FITC and Texas Red, even without consideration of autofluorescence.

  16. Combining terrestrial laser scanning and physical modelling experiments to characterise the structure and drag of vegetation.

    NASA Astrophysics Data System (ADS)

    Vasilopoulos, Grigorios; Leyland, Julian; Nield, Joanna

    2016-04-01

    Vegetation affects flow and, because of its ubiquity in nature, plays a significant role in modulating geomorphic change. Plants function as large-scale obstacles that exert additional drag on water flows. The vegetative drag applied is a function of the structure and configuration of the plant and these attributes influence both local scale turbulence and the structure of the boundary layer. Whilst several approaches have been developed to describe the relationship between plant structure and drag, such as using bulk parameters, geometric analogies or porous medium approaches, they have previously failed to accurately and precisely characterise the vegetation itself. Terrestrial Laser Scanning (TLS) has the ability to capture structures and forms in 3D with high resolution, precision and accuracy, which provides an opportunity to accurately describe vegetation structure. However, TLS data are essentially an aggregate of dimensionless points in space and the complexity of vegetation biomass means that some of the measured points are erroneous. A method has been developed that is capable of accurately characterising vegetation structure in 3D from dense TLS point cloud data, using a porosity approach. The corresponding fluvial drag of the vegetation is measured in a flume, using a bulk roughness function calculated from precise measurements of water surface slope and a series of high resolution acoustic Doppler velocimetry (ADV) measurements. A series of structurally variable plants were characterised using the methods outlined above and the results are presented herein.

  17. Determination of the thickness and structure of the skin barrier by in vivo laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Richter, H.; Astner, S.; Patzelt, A.; Knorr, F.; Sterry, W.; Antoniou, Ch

    2008-04-01

    Normal skin barrier function is an essential aspect of skin homeostasis and regeneration. Dynamic inflammatory, proliferative and neoplastic skin processes such as wound healing, psoriasis and contact dermatitis are associated with a significant disruption of the skin barrier. In recent years, there has been increasing interest in evaluating cosmetic and pharmacologic products for their ability to restore these protective properties. The gold standard for characterization of barrier function has been the measurement of the transepidermal water loss, however the disadvantage of this method is its interference with several endogenous and exogenous factors such as hydration, perspiration and topically applied substances. This study was aimed to test the clinical applicability of a fluorescence confocal laser scanning microscope (LSM) for a systematic morphologic analysis of the structure, integrity and thickness of the stratum corneum in 10 otherwise healthy volunteers. The influence of skin treatment with commercial moisturizing cream on skin barrier function was evaluated in serial non-invasive examinations. Our findings showed that in vivo LSM may represent a simple and efficient method for the characterization of skin barrier properties, such as the thickness and hydration of the stratum corneum.

  18. Spectral analysis of irregular roughness artifacts measured by atomic force microscopy and laser scanning microscopy.

    PubMed

    Chen, Yuhang; Luo, Tingting; Ma, Chengfu; Huang, Wenhao; Gao, Sitian

    2014-12-01

    Atomic force microscopy (AFM) and laser scanning microscopy (LSM) measurements on a series of specially designed roughness artifacts were performed and the results characterized by spectral analysis. As demonstrated by comparisons, both AFM and LSM can image the complex structures with high resolution and fidelity. When the surface autocorrelation length increases from 200 to 500 nm, the cumulative power spectral density spectra of the design, AFM and LSM data reach a better agreement with each other. The critical wavelength of AFM characterization is smaller than that of LSM, and the gap between the measured and designed critical wavelengths is reduced with an increase in the surface autocorrelation length. Topography measurements of surfaces with a near zero or negatively skewed height distribution were determined to be accurate. However, obvious discrepancies were found for surfaces with a positive skewness owing to more severe dilations of either the solid tip of the AFM or the laser tip of the LSM. Further surface parameter evaluation and template matching analysis verified that the main distortions in AFM measurements are tip dilations while those in LSM are generally larger and more complex.

  19. Resolution enhancement of digital laser scanning fluorescence microscopy with a dual-lens optical pickup head

    NASA Astrophysics Data System (ADS)

    Tsai, Rung-Ywan; Chen, Jung-Po; Lee, Yuan-Chin; Chiang, Hung-Chih; Huang, Tai-Ting; Huang, Chun-Chieh; Cheng, Chih-Ming; Cheng, Chung-Ta; Lo, Feng-Hsiang; Tiao, Golden

    2016-10-01

    The resolution of the cell fluorescence image captured by a digital laser scanning microscopy with a modified dual-lens BD-ROM optical pickup head is enhanced by image registration and double sample frequency. A dual objective lens of red (655 nm) and blue (405 or 488 nm) laser sources with numerical apertures of 0.6 and 0.85 is used for sample focusing and position tracking and cell fluorescence image capturing, respectively. The image registration and capturing frequency are based on the address-coded patterns of a sample slide. The address-coded patterns are designed as a string of binary code, which comprises a plurality of base-straight lands and grooves and data-straight grooves. The widths of the base-straight lands, base-straight grooves, and data-straight grooves are 0.38, 0.38, and 0.76 μm, respectively. The numbers of sample signals in the x-direction are measured at every intersection point by intersecting the base intensity of the push-pull signal of the address-coded patterns, which has a minimum spacing of 0.38 μm. After taking a double sample frequency, the resolution of the measured cell fluorescence image is enhanced from 0.38 μm to the diffraction limit of the objective lens.

  20. Virtual Reconstruction of the Almaqah Temple of Yeha in Ethiopia by Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Lindstaedt, M.; Mechelke, K.; Schnelle, M.; Kersten, Th.

    2011-09-01

    In autumn 2009 the Almaqah Temple of Yeha in Ethiopia has been recorded by terrestrial laser scanning and digital photogrammetry in cooperation between the Sana'a Branch of the Orient Department of the German Archaeological Institute and the HafenCity University Hamburg. The temple dates from the 7th Century BC and is one of the best preserved buildings of Sabaean architecture in Africa. As a basis for all future project works a geodetic network was established in UTM-coordinates by GPS measurements. The geodata collected will form the basis for all future work on the temple. The deformations of the facades were determined for restoration issues and the existing parts of the temple were modelled by meshing (3D triangulation). Using the scanned point cloud and a technical analysis of the building the Propylon, which is no longer existent today, was virtually reconstructed. In future, the data will also be included in the master plan for touristic development of the region of Axum and Yeha in northern Ethiopia.

  1. Terrestrial laser scanning observations of geomorphic changes and varying lava lake levels at Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Jones, Laura K.; Kyle, Philip R.; Oppenheimer, Clive; Frechette, Jedediah D.; Okal, Marianne H.

    2015-03-01

    A Terrestrial Laser Scanning (TLS) instrument was used to image the topography of the Main Crater at Erebus volcano each December in 2008, 2009, and 2010. Our high-spatial resolution TLS scans provide unique insights into annual and decadal scale geomorphic evolution of the summit area when integrated with comparable data collected by an airborne instrument in 2001. We observe both a pattern of subsidence within the Inner Crater of the volcano and an ~ 3 m per-year drop in the lava lake level over the same time period that are suggestive of decreasing overpressure in an underlying magma reservoir. We also scanned the active phonolite lava lake hosted within the Inner Crater, and recorded rapid cyclic fluctuations in the level of the lake. These were sporadically interrupted by minor explosions by bursting gas bubbles at the lake surface. The TLS data permit calculation of lake level rise and fall speeds and associated rates of volumetric change within the lake. These new observations, when considered with prior determinations of rates of lake surface motion and gas output, are indicative of unsteady magma flow in the conduit and its associated variability in gas volume fraction.

  2. Dynamic occlusion detection and inpainting of in situ captured terrestrial laser scanning point clouds sequence

    NASA Astrophysics Data System (ADS)

    Chen, Chi; Yang, Bisheng

    2016-09-01

    Laser point clouds captured using terrestrial laser scanning (TLS) in an uncontrollable urban outdoor or indoor scene suffer from irregular shaped data blanks caused by dynamic occlusion that temporarily exists, i.e., moving objects, such as pedestrians or cars, resulting in integrality and quality losses of the scene data. This paper proposes a novel automatic dynamic occlusion detection and inpainting method for sequential TLS point clouds captured from one scan position. In situ collected laser point clouds sequences are indexed by establishing a novel panoramic space partition that assigns a three dimensional voxel to each laser point according to the scanning setups. Then two stationary background models are constructed at the ray voxel level using the laser reflectance intensity and geometrical attributes of the point set inside each voxel across the TLS sequence. Finally, the background models are combined to detect the points on the dynamic object, and the ray voxels of the detected dynamic points are tracked for further inpainting by replacing the ray voxels with the corresponding background voxels from another scan. The resulting scene is free of dynamic occlusions. Experiments validated the effectiveness of the proposed method for indoor and outdoor TLS point clouds captured by a commercial terrestrial scanner. The proposed method achieves high precision and recall rate for dynamic occlusion detection and produces clean inpainted point clouds for further processing.

  3. Laser-scanning coherent anti-Stokes Raman scattering microscopy and applications to cell biology.

    PubMed Central

    Cheng, Ji-Xin; Jia, Y Kevin; Zheng, Gengfeng; Xie, X Sunney

    2002-01-01

    Laser-scanning coherent anti-Stokes Raman scattering (CARS) microscopy with fast data acquisition and high sensitivity has been developed for vibrational imaging of live cells. High three-dimensional (3D) resolution is achieved with two collinearly overlapped near infrared picosecond beams and a water objective with a high numerical aperture. Forward-detected CARS (F-CARS) and epi-detected CARS (E-CARS) images are recorded simultaneously. F-CARS is used for visualizing features comparable to or larger than the excitation wavelength, while E-CARS allows detection of smaller features with a high contrast. F-CARS and E-CARS images of live and unstained cells reveal details invisible in differential interference-contrast images. High-speed vibrational imaging of unstained cells undergoing mitosis and apoptosis has been carried out. For live NIH 3T3 cells in metaphase, 3D distribution of chromosomes is mapped at the frequency of the DNA backbone Raman band, while the vesicles surrounding the nucleus is imaged by E-CARS at the frequency of the C-H stretching Raman band. Apoptosis in NIH 3T3 cells is monitored using the CARS signal from aliphatic C-H stretching vibration. PMID:12080137

  4. Changes in cortical microvasculature during misery perfusion measured by two-photon laser scanning microscopy.

    PubMed

    Tajima, Yosuke; Takuwa, Hiroyuki; Kokuryo, Daisuke; Kawaguchi, Hiroshi; Seki, Chie; Masamoto, Kazuto; Ikoma, Yoko; Taniguchi, Junko; Aoki, Ichio; Tomita, Yutaka; Suzuki, Norihiro; Kanno, Iwao; Saeki, Naokatsu; Ito, Hiroshi

    2014-08-01

    This study aimed to examine the cortical microvessel diameter response to hypercapnia in misery perfusion using two-photon laser scanning microscopy (TPLSM). We evaluated whether the vascular response to hypercapnia could represent the cerebrovascular reserve. Cerebral blood flow (CBF) during normocapnia and hypercapnia was measured by laser-Doppler flowmetry through cranial windows in awake C57/BL6 mice before and at 1, 7, 14, and 28 days after unilateral common carotid artery occlusion (UCCAO). Diameters of the cortical microvessels during normocapnia and hypercapnia were also measured by TPLSM. Cerebral blood flow and the vascular response to hypercapnia were decreased after UCCAO. Before UCCAO, vasodilation during hypercapnia was found primarily in arterioles (22.9%±3.5%). At 14 days after UCCAO, arterioles, capillaries, and venules were autoregulatorily dilated by 79.5%±19.7%, 57.2%±32.3%, and 32.0%±10.8%, respectively. At the same time, the diameter response to hypercapnia in arterioles was significantly decreased to 1.9%±1.5%. A significant negative correlation was observed between autoregulatory vasodilation and the diameter response to hypercapnia in arterioles. Our findings indicate that arterioles play main roles in both autoregulatory vasodilation and hypercapnic vasodilation, and that the vascular response to hypercapnia can be used to estimate the cerebrovascular reserve.

  5. Multi-frequency AOM for multi-beam laser scanning exposure system

    NASA Astrophysics Data System (ADS)

    Shinada, Hidetoshi

    2016-08-01

    Digital printing systems recorded on films or computer to plates (CTPs) have been required to improve their productivity and image quality. Under the circumstance, a printing technology of the multi-beam laser scanning for the drum capstan system, which is almost the same as optics configuration as the flat bed system, was developed using a newly developed multi-frequency acousto-optic modulator (AOM) as a key device instead of ultra-fast scanning devices toward a main scan direction. The multi-frequency AOM was developed with phased array-type transducers, achieving a wider bandwidth of over 160 MHz. The design consisted of a simultaneous three beams generation with interlace scan to avoid the beat effect by adjacent Doppler-shifted beams, which consequently attained the fastest recording speed of 5.0 mm/s compared with 2.0-3.0 mm/s of existing systems in those days. Furthermore, a couple of critical parameters of the multi-frequency AOM are studied, for example, a treatment of third-order intermodulation and also beat effect in connection with photosensitive media. As a result, the necessity of interlaces scanning to obtain good image quality without beat effect and also to allow a lower laser power to apply is proposed.

  6. Automatic Registration of Terrestrial Laser Scanning Point Clouds using Panoramic Reflectance Images.

    PubMed

    Kang, Zhizhong; Li, Jonathan; Zhang, Liqiang; Zhao, Qile; Zlatanova, Sisi

    2009-01-01

    This paper presents a new approach to the automatic registration of terrestrial laser scanning (TLS) point clouds using panoramic reflectance images. The approach follows a two-step procedure that includes both pair-wise registration and global registration. The pair-wise registration consists of image matching (pixel-to-pixel correspondence) and point cloud registration (point-to-point correspondence), as the correspondence between the image and the point cloud (pixel-to-point) is inherent to the reflectance images. False correspondences are removed by a geometric invariance check. The pixel-to-point correspondence and the computation of the rigid transformation parameters (RTPs) are integrated into an iterative process that allows for the pair-wise registration to be optimised. The global registration of all point clouds is obtained by a bundle adjustment using a circular self-closure constraint. Our approach is tested with both indoor and outdoor scenes acquired by a FARO LS 880 laser scanner with an angular resolution of 0.036° and 0.045°, respectively. The results show that the pair-wise and global registration accuracies are of millimetre and centimetre orders, respectively, and that the process is fully automatic and converges quickly. PMID:22574036

  7. Parallel Processing Method for Airborne Laser Scanning Data Using a PC Cluster and a Virtual Grid.

    PubMed

    Han, Soo Hee; Heo, Joon; Sohn, Hong Gyoo; Yu, Kiyun

    2009-01-01

    In this study, a parallel processing method using a PC cluster and a virtual grid is proposed for the fast processing of enormous amounts of airborne laser scanning (ALS) data. The method creates a raster digital surface model (DSM) by interpolating point data with inverse distance weighting (IDW), and produces a digital terrain model (DTM) by local minimum filtering of the DSM. To make a consistent comparison of performance between sequential and parallel processing approaches, the means of dealing with boundary data and of selecting interpolation centers were controlled for each processing node in parallel approach. To test the speedup, efficiency and linearity of the proposed algorithm, actual ALS data up to 134 million points were processed with a PC cluster consisting of one master node and eight slave nodes. The results showed that parallel processing provides better performance when the computational overhead, the number of processors, and the data size become large. It was verified that the proposed algorithm is a linear time operation and that the products obtained by parallel processing are identical to those produced by sequential processing. PMID:22574032

  8. Automatic Registration of Terrestrial Laser Scanning Point Clouds using Panoramic Reflectance Images

    PubMed Central

    Kang, Zhizhong; Li, Jonathan; Zhang, Liqiang; Zhao, Qile; Zlatanova, Sisi

    2009-01-01

    This paper presents a new approach to the automatic registration of terrestrial laser scanning (TLS) point clouds using panoramic reflectance images. The approach follows a two-step procedure that includes both pair-wise registration and global registration. The pair-wise registration consists of image matching (pixel-to-pixel correspondence) and point cloud registration (point-to-point correspondence), as the correspondence between the image and the point cloud (pixel-to-point) is inherent to the reflectance images. False correspondences are removed by a geometric invariance check. The pixel-to-point correspondence and the computation of the rigid transformation parameters (RTPs) are integrated into an iterative process that allows for the pair-wise registration to be optimised. The global registration of all point clouds is obtained by a bundle adjustment using a circular self-closure constraint. Our approach is tested with both indoor and outdoor scenes acquired by a FARO LS 880 laser scanner with an angular resolution of 0.036° and 0.045°, respectively. The results show that the pair-wise and global registration accuracies are of millimetre and centimetre orders, respectively, and that the process is fully automatic and converges quickly. PMID:22574036

  9. Fast and Robust STEM Reconstruction in Complex Environments Using Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Wang, D.; Hollaus, M.; Puttonen, E.; Pfeifer, N.

    2016-06-01

    Terrestrial Laser Scanning (TLS) is an effective tool in forest research and management. However, accurate estimation of tree parameters still remains challenging in complex forests. In this paper, we present a novel algorithm for stem modeling in complex environments. This method does not require accurate delineation of stem points from the original point cloud. The stem reconstruction features a self-adaptive cylinder growing scheme. This algorithm is tested for a landslide region in the federal state of Vorarlberg, Austria. The algorithm results are compared with field reference data, which show that our algorithm is able to accurately retrieve the diameter at breast height (DBH) with a root mean square error (RMSE) of ~1.9 cm. This algorithm is further facilitated by applying an advanced sampling technique. Different sampling rates are applied and tested. It is found that a sampling rate of 7.5% is already able to retain the stem fitting quality and simultaneously reduce the computation time significantly by ~88%.

  10. Adaptive circle-ellipse fitting method for estimating tree diameter based on single terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Bu, Guochao; Wang, Pei

    2016-04-01

    Terrestrial laser scanning (TLS) has been used to extract accurate forest biophysical parameters for inventory purposes. The diameter at breast height (DBH) is a key parameter for individual trees because it has the potential for modeling the height, volume, biomass, and carbon sequestration potential of the tree based on empirical allometric scaling equations. In order to extract the DBH from the single-scan data of TLS automatically and accurately within a certain range, we proposed an adaptive circle-ellipse fitting method based on the point cloud transect. This proposed method can correct the error caused by the simple circle fitting method when a tree is slanted. A slanted tree was detected by the circle-ellipse fitting analysis, then the corresponding slant angle was found based on the ellipse fitting result. With this information, the DBH of the trees could be recalculated based on reslicing the point cloud data at breast height. Artificial stem data simulated by a cylindrical model of leaning trees and the scanning data acquired with the RIEGL VZ-400 were used to test the proposed adaptive fitting method. The results shown that the proposed method can detect the trees and accurately estimate the DBH for leaning trees.

  11. a Semi-Automatic Procedure for Texturing of Laser Scanning Point Clouds with Google Streetview Images

    NASA Astrophysics Data System (ADS)

    Lichtenauer, J. F.; Sirmacek, B.

    2015-08-01

    We introduce a method to texture 3D urban models with photographs that even works for Google Streetview images and can be done with currently available free software. This allows realistic texturing, even when it is not possible or cost-effective to (re)visit a scanned site to take textured scans or photographs. Mapping a photograph onto a 3D model requires knowledge of the intrinsic and extrinsic camera parameters. The common way to obtain intrinsic parameters of a camera is by taking several photographs of a calibration object with a priori known structure. The extra challenge of using images from a database such as Google Streetview, rather than your own photographs, is that it does not allow for any controlled calibration. To overcome this limitation, we propose to calibrate the panoramic viewer of Google Streetview using Structure from Motion (SfM) on any structure of which Google Streetview offers views from multiple angles. After this, the extrinsic parameters for any other view can be calculated from 3 or more tie points between the image from Google Streetview and a 3D model of the scene. These point correspondences can either be obtained automatically or selected by manual annotation. We demonstrate how this procedure provides realistic 3D urban models in an easy and effective way, by using it to texture a publicly available point cloud from a terrestrial laser scan made in Bremen, Germany, with a screenshot from Google Streetview, after estimating the focal length from views from Paris, France.

  12. A two-dimensional laser scanning mirror using motion-decoupling electromagnetic actuators.

    PubMed

    Shin, Bu Hyun; Oh, Dongho; Lee, Seung-Yop

    2013-03-27

    This work proposes a two-dimensional (2-D) laser scanning mirror with a novel actuating structure composed of one magnet and two coils. The mirror-actuating device generates decoupled scanning motions about two orthogonal axes by combining two electromagnetic actuators of the conventional moving-coil and the moving-magnet types. We implement a finite element analysis to calculate magnetic flux in the electromagnetic system and experiments using a prototype with the overall size of 22 mm (W) × 20 mm (D) × 15 mm (H) for the mirror size of 8 mm × 8 mm. The upper moving-coil type actuator to rotate only the mirror part has the optical reflection angle of 15.7° at 10 Hz, 90° at the resonance frequency of 60 Hz at ±3 V (±70 mA) and the bandwidth of 91 Hz. The lower moving-magnet type actuator has the optical reflection angle of 16.20° at 10 Hz and 50° at the resonance frequency of 60 Hz at ±5 V (±34 mA) and the bandwidth of 88 Hz. The proposed compact and simple 2-D scanning mirror has advantages of large 2-D angular deflections, wide frequency bandwidth and low manufacturing cost.

  13. Plasmon resonance and the imaging of metal-impregnated neurons with the laser scanning confocal microscope

    PubMed Central

    Thompson, Karen J; Harley, Cynthia M; Barthel, Grant M; Sanders, Mark A; Mesce, Karen A

    2015-01-01

    The staining of neurons with silver began in the 1800s, but until now the great resolving power of the laser scanning confocal microscope has not been utilized to capture the in-focus and three-dimensional cytoarchitecture of metal-impregnated cells. Here, we demonstrate how spectral confocal microscopy, typically reserved for fluorescent imaging, can be used to visualize metal-labeled tissues. This imaging does not involve the reflectance of metal particles, but rather the excitation of silver (or gold) nanoparticles and their putative surface plasmon resonance. To induce such resonance, silver or gold particles were excited with visible-wavelength laser lines (561 or 640 nm), and the maximal emission signal was collected at a shorter wavelength (i.e., higher energy state). Because the surface plasmon resonances of noble metal nanoparticles offer a superior optical signal and do not photobleach, our novel protocol holds enormous promise of a rebirth and further development of silver- and gold-based cell labeling protocols. DOI: http://dx.doi.org/10.7554/eLife.09388.001 PMID:26670545

  14. Methodology of evaluation of abrasive tool wear with the use of laser scanning microscopy.

    PubMed

    Lipiński, Dariusz; Kacalak, Wojciech; Tomkowski, Robert

    2014-01-01

    Grinding is one of the basic precise material removal methods. Abrasive and shape wear, as well as smearing of the tools' active surface handicap the processing results. The loss of cutting capacity in abrasive tools or alteration of their shape influences the surface quality and precision of the workpiece dimensions and its shape. Evaluation of the abrasive tool surface is the basic criterion of forecasting the tools' durability and the process results. The applied method of laser scanning made determination of the surface coordinates and subsequently of its geometric features with micrometric accuracy possible. Using the information on the abrasive tool surface geometric structure, a methodology of evaluation of the level of changes in geometric features of the tool during the grinding process was developed. Criteria for evaluation of the level of abrasive grains attritious wear, the degree of smearing of the abrasive tool surface and evaluation of the cutting capability of the abrasive tools were determined. The developed method allowed for evaluation of the level of abrasive tools' wear, and subsequently formed foundations for assessment of the influence of the grinding parameters on the durability of abrasive tools, evaluation of the influence of the parameters of the process of shaping the abrasive tools' active surfaces on their geometric characteristics and evaluation of the level of correlation between the monitored process parameters and the degree of the abrasive tools' wear.

  15. Towards Automatic Single-Sensor Mapping by Multispectral Airborne Laser Scanning

    NASA Astrophysics Data System (ADS)

    Ahokas, E.; Hyyppä, J.; Yu, X.; Liang, X.; Matikainen, L.; Karila, K.; Litkey, P.; Kukko, A.; Jaakkola, A.; Kaartinen, H.; Holopainen, M.; Vastaranta, M.

    2016-06-01

    This paper describes the possibilities of the Optech Titan multispectral airborne laser scanner in the fields of mapping and forestry. Investigation was targeted to six land cover classes. Multispectral laser scanner data can be used to distinguish land cover classes of the ground surface, including the roads and separate road surface classes. For forest inventory using point cloud metrics and intensity features combined, total accuracy of 93.5% was achieved for classification of three main boreal tree species (pine, spruce and birch).When using intensity features - without point height metrics - a classification accuracy of 91% was achieved for these three tree species. It was also shown that deciduous trees can be further classified into more species. We propose that intensity-related features and waveform-type features are combined with point height metrics for forest attribute derivation in area-based prediction, which is an operatively applied forest inventory process in Scandinavia. It is expected that multispectral airborne laser scanning can provide highly valuable data for city and forest mapping and is a highly relevant data asset for national and local mapping agencies in the near future.

  16. Improved Correction Method for Water-Refracted Terrestrial Laser Scanning Data Acquired in the Mountain Channel

    NASA Astrophysics Data System (ADS)

    Miura, N.; Asano, Y.; Moribe, Y.

    2016-06-01

    Detailed information of underwater topography is required for better understanding and prediction of water and sediment transport in a mountain channel. Recent research showed promising utility of green-wavelength Terrestrial Laser Scanning (TLS) for measuring submerged stream-bed structure in fluvial environment. However, difficulty in acquiring reliable underwater data has been remained in the part of mountain channel where water surface has some gradient. Since horizontal water surface was a major premise for the existing water refraction correction method, significant error was resulted in such area. Therefore, this paper presents a modified method to correct water-refracted TLS data acquired over mountain channel with complex water-surface slope. Applicability of the modified method was validated using the field data and compared with the existing correction method and non-corrected data. The results showed that the modified method has much smaller error with RMSE value of 3 mm than the existing method (RMSE = 10 mm) and non-corrected data (RMSE = 23 mm). Presented method successfully corrected water-refracted TLS data acquired over sloped channel. This would enable us to quantitatively measure whole units of complex mountain channels, and help us to understand water dynamics better in the area.

  17. In Vivo Laser Scanning Confocal Microscopy of Human Meibomian Glands in Aging and Ocular Surface Diseases

    PubMed Central

    Fasanella, Vincenzo; Mastropasqua, Rodolfo; Brescia, Lorenza; Di Staso, Federico; Ciancaglini, Marco; Mastropasqua, Leonardo

    2016-01-01

    Meibomian glands (MGs) play a crucial role in the ocular surface homeostasis by providing lipids to the superficial tear film. Their dysfunction destabilizes the tear film leading to a progressive loss of the ocular surface equilibrium and increasing the risk for dry eye. In fact, nowadays, the meibomian gland dysfunction is one of the leading causes of dry eye. Over the past decades, MGs have been mainly studied by using meibography, which, however, cannot image the glandular structure at a cellular level. The diffusion of the in vivo laser scanning confocal microscopy (LSCM) provided a new approach for the structural assessment of MGs permitting a major step in the noninvasive evaluation of these structures. LSCM is capable of showing MGs modifications during aging and in the most diffuse ocular surface diseases such as dry eye, allergy, and autoimmune conditions and in the drug-induced ocular surface disease. On the other hand, LSCM may help clinicians in monitoring the tissue response to therapy. In this review, we summarized the current knowledge about the role of in vivo LSCM in the assessment of MGs during aging and in the most diffuse ocular surface diseases. PMID:27047965

  18. Application of Laser Scanning Confocal Microscopy to Heat and Mass Transport Modeling in Porous Microstructures

    NASA Technical Reports Server (NTRS)

    Marshall, Jochen; Milos, Frank; Fredrich, Joanne; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    Laser Scanning Confocal Microscopy (LSCM) has been used to obtain digital images of the complicated 3-D (three-dimensional) microstructures of rigid, fibrous thermal protection system (TPS) materials. These orthotropic materials are comprised of refractory ceramic fibers with diameters in the range of 1 to 10 microns and have open porosities of 0.8 or more. Algorithms are being constructed to extract quantitative microstructural information from the digital data so that it may be applied to specific heat and mass transport modeling efforts; such information includes, for example, the solid and pore volume fractions, the internal surface area per volume, fiber diameter distributions, and fiber orientation distributions. This type of information is difficult to obtain in general, yet it is directly relevant to many computational efforts which seek to model macroscopic thermophysical phenomena in terms of microscopic mechanisms or interactions. Two such computational efforts for fibrous TPS materials are: i) the calculation of radiative transport properties; ii) the modeling of gas permeabilities.

  19. Sealing ability of three root-end filling materials prepared using an erbium: Yttrium aluminium garnet laser and endosonic tip evaluated by confocal laser scanning microscopy

    PubMed Central

    Nanjappa, A Salin; Ponnappa, KC; Nanjamma, KK; Ponappa, MC; Girish, Sabari; Nitin, Anita

    2015-01-01

    Aims: (1) To compare the sealing ability of mineral trioxide aggregate (MTA), Biodentine, and Chitra-calcium phosphate cement (CPC) when used as root-end filling, evaluated under confocal laser scanning microscope using Rhodamine B dye. (2) To evaluate effect of ultrasonic retroprep tip and an erbium:yttrium aluminium garnet (Er:YAG) laser on the integrity of three different root-end filling materials. Materials and Methods: The root canals of 80 extracted teeth were instrumented and obturated with gutta-percha. The apical 3 mm of each tooth was resected and 3 mm root-end preparation was made using ultrasonic tip (n = 30) and Er:YAG laser (n = 30). MTA, Biodentine, and Chitra-CPC were used to restore 10 teeth each. The samples were coated with varnish and after drying, they were immersed in Rhodamine B dye for 24 h. The teeth were then rinsed, sectioned longitudinally, and observed under confocal laser scanning microscope. Statistical Analysis Used: Data were analyzed using one-way analysis of variance (ANOVA) and a post-hoc Tukey's test at P < 0.05 (R software version 3.1.0). Results: Comparison of microleakage showed maximum peak value of 0.45 mm for Biodentine, 0.85 mm for MTA, and 1.05 mm for Chitra-CPC. The amount of dye penetration was found to be lesser in root ends prepared using Er:YAG laser when compared with ultrasonics, the difference was found to be statistically significant (P < 0.05). Conclusions: Root-end cavities prepared with Er:YAG laser and restored with Biodentine showed superior sealing ability compared to those prepared with ultrasonics. PMID:26180420

  20. Assessing modern ground survey methods and airborne laser scanning for digital terrain modelling: A case study from the Lake District, England

    NASA Astrophysics Data System (ADS)

    Gallay, Michal; Lloyd, Christopher D.; McKinley, Jennifer; Barry, Lorraine

    2013-02-01

    This paper compares the applicability of three ground survey methods for modelling terrain: one man electronic tachymetry (TPS), real time kinematic GPS (GPS), and terrestrial laser scanning (TLS). Vertical accuracy of digital terrain models (DTMs) derived from GPS, TLS and airborne laser scanning (ALS) data is assessed. Point elevations acquired by the four methods represent two sections of a mountainous area in Cumbria, England. They were chosen so that the presence of non-terrain features is constrained to the smallest amount. The vertical accuracy of the DTMs was addressed by subtracting each DTM from TPS point elevations. The error was assessed using exploratory measures including statistics, histograms, and normal probability plots. The results showed that the internal measurement accuracy of TPS, GPS, and TLS was below a centimetre. TPS and GPS can be considered equally applicable alternatives for sampling the terrain in areas accessible on foot. The highest DTM vertical accuracy was achieved with GPS data, both on sloped terrain (RMSE 0.16 m) and flat terrain (RMSE 0.02 m). TLS surveying was the most efficient overall but veracity of terrain representation was subject to dense vegetation cover. Therefore, the DTM accuracy was the lowest for the sloped area with dense bracken (RMSE 0.52 m) although it was the second highest on the flat unobscured terrain (RMSE 0.07 m). ALS data represented the sloped terrain more realistically (RMSE 0.23 m) than the TLS. However, due to a systematic bias identified on the flat terrain the DTM accuracy was the lowest (RMSE 0.29 m) which was above the level stated by the data provider. Error distribution models were more closely approximated by normal distribution defined using median and normalized median absolute deviation which supports the use of the robust measures in DEM error modelling and its propagation.

  1. Ground Deformation Analysis of Blast-Induced Liquefaction at a Simulated Airport Infrastructure Using High Resolution 3D Laser Scanning

    NASA Astrophysics Data System (ADS)

    Minasian, D.; Kayen, R.; Ashford, S.; Kawamata, Y.; Sugano, T.

    2008-12-01

    In October 2007, the Port and Airport Research Institute (PARI) of the Japan Ministry of Land, Infrastructure and Transportation conducted a large-scale blast-induced liquefaction experiment in Ishikari, Hokkaido, Japan. Approximately 24,000 m2 of ground was liquefied using controlled blasting techniques to investigate the performance of airport infrastructure. The USGS and Oregon State University participated in the study and measured topographic changes in ground level using 3D laser scanning techniques (terrestrial lidar), as well as changes in shear wave velocity of the between the pre- and post-liquefied soil. This poster focuses on the lidar results. The overall objective of the PARI experiment is to assess the performance of airport infrastructure subjected to liquefaction. Specifically, the performance of pipelines and large concrete utility raceways located beneath runway pavements is of interest, as well as the performance of pavements and embankments with and without soil improvement techniques. At the site, 5-7 m of loose silty sand was placed as hydraulic fill on natural alluvial sand as an expansion of the Ishikari port facility. On a portion of the liquefied site, three 20 m by 50 m test sections were constructed to investigate the performance of improved ground beneath asphalt runways, concrete runway aprons, and open areas. Pipelines and concrete utility conduits were also buried in each section. The three ground improvement techniques investigated were sand-cement mixing, vertical drains, and colloidal silica injection. The PARI experiment provided an excellent opportunity to conduct terrestrial lidar measurements - a revolutionary tool for accurate characterization of fine-scale changes of topography and identification of subtle deformations. Lidar was used for characterizing post-blast deformations both immediately after the charges were used, and subsequently over time at intervals of 2 days, 4 days, and 5 months after blasting. Settlement

  2. Standing-wave-excited multiplanar fluorescence in a laser scanning microscope reveals 3D information on red blood cells

    NASA Astrophysics Data System (ADS)

    Amor, Rumelo; Mahajan, Sumeet; Amos, William Bradshaw; McConnell, Gail

    2014-12-01

    Standing-wave excitation of fluorescence is highly desirable in optical microscopy because it improves the axial resolution. We demonstrate here that multiplanar excitation of fluorescence by a standing wave can be produced in a single-spot laser scanning microscope by placing a plane reflector close to the specimen. We report here a variation in the intensity of fluorescence of successive planes related to the Stokes shift of the dye. We show by the use of dyes specific for the cell membrane how standing-wave excitation can be exploited to generate precise contour maps of the surface membrane of red blood cells, with an axial resolution of ~90 nm. The method, which requires only the addition of a plane mirror to an existing confocal laser scanning microscope, may well prove useful in studying diseases which involve the red cell membrane, such as malaria.

  3. Analysis of a head-mounted display-type multifocus display system using a laser scanning method

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Wook; Kwon, Yong-Moo; Park, Q.-Han; Kim, Sung-Kyu

    2011-03-01

    We developed a head-mounted display (HMD)-type multifocus display system using a laser-scanning method to provide an accommodation effect for viewers. This accomplishment indicates that providing a monocular depth cue is possible through this multifocus system. In the system, the optical path is changed by a scanning action. To provide an accurate accommodation effect for the viewer, the multifocus display system is designed and manufactured in accordance with the geometric analysis of the system's scanning action. Using a video camera as a substitute for the viewer, correct focus adjustment without the scanning action problem is demonstrated. By analyzing the scanning action and experimental results, we are able to illustrate the formation of a viewpoint in an HMD-type multifocus display system using a laser-scanning method. In addition, we demonstrate that the accommodation effect could be provided independent of the viewing condition of the viewer.

  4. Standing-wave-excited multiplanar fluorescence in a laser scanning microscope reveals 3D information on red blood cells.

    PubMed

    Amor, Rumelo; Mahajan, Sumeet; Amos, William Bradshaw; McConnell, Gail

    2014-12-08

    Standing-wave excitation of fluorescence is highly desirable in optical microscopy because it improves the axial resolution. We demonstrate here that multiplanar excitation of fluorescence by a standing wave can be produced in a single-spot laser scanning microscope by placing a plane reflector close to the specimen. We report here a variation in the intensity of fluorescence of successive planes related to the Stokes shift of the dye. We show by the use of dyes specific for the cell membrane how standing-wave excitation can be exploited to generate precise contour maps of the surface membrane of red blood cells, with an axial resolution of ≈90 nm. The method, which requires only the addition of a plane mirror to an existing confocal laser scanning microscope, may well prove useful in studying diseases which involve the red cell membrane, such as malaria.

  5. Mass movement monitoring by Terrestrial Laser Scanning on Madeira Island (Portugal)

    NASA Astrophysics Data System (ADS)

    Wiatr, T.; Reicherter, K.; Fernández-Steeger, T.; Rodrigues, D.

    2009-04-01

    The terrestrial laser scanning (TLS) is an effective remote sensing technology for reconstruction and observation of mass movement phenomena and related hazards as it is well founded of high spatial and temporal resolution. TLS has been used for the investigation of landslides (slides, rock falls, and flows) at different sites on the volcanic island of Madeira, Portugal. These mass movements provide a potential hazard for population and infrastructure and led to fatalities and serious damages in the past. First measurements have been conducted in spring 2008 and a second campaign took place in fall 2008. In the future, semi-annual laser scanning will provide the possibility to establish a monitoring and to identify the mechanisms of mass movements in detail. The data acquisition with the TLS method and high-resolution spatial surface analysis can help to improve data quality and density for a higher accurate monitoring and subsequently better prediction of the mass movements. Major aims of our investigation are to find quantitative and qualitative data for the engineering geology. In this context the detailed structural analysis of rock surfaces and the slope stability analysis are fundamental. Other scientific goals are the analysis of rock surface roughness in different scales and types, which is of interest to determine relative age and exposure of rock faces and is of importance for engineering geological stability analysis. Besides this small scale roughness analysis (mm - dm), investigation of terrain roughness from high resolution digital elevation models (HRDEM) for rock fall modelling, but also geomorphologic studies for hazard analysis is important. HRDEM can help to describe terrace developments, debris cones or ancient landslides and their interactions in terrain evolution. Especially these hidden elements are important to quantify processes for historical landslide analysis in the course of a hazard analysis. Furthermore the intensity of reflexivity of

  6. Application of terrestrial laser scanning for coastal geomorphologic research questions in western Greece

    NASA Astrophysics Data System (ADS)

    Hoffmeister, Dirk; Curdt, Constanze; Tilly, Nora; Ntageretzis, Konstantin; Aasen, Helge; Vött, Andreas; Bareth, Georg

    2013-04-01

    Coasts are areas of permanent change, influenced by gradual changes and sudden impacts. In particular, western Greece is a tectonically active region, due to the nearby plate boundary of the Hellenic Arc. The region has suffered from numerous earthquakes and tsunamis during prehistoric and historic times and is thus characterized by a high seismic and tsunami hazard risk. Additionally, strong winter storms may reach considerable dimensions. In this study, terrestrial laser scanning was applied for (i) annual change detection at seven coastal areas of western Greece for three years (2009-2011) and (ii) accurate parameter detection of large boulders, dislocated by high-energy wave impacts. The Riegl LMS-Z420i laser scanner was used in combination with a precise DGPS system (Topcon HiPer Pro) for all surveys. Each scan position and a further target were recorded for georeferencing and merging of the point clouds. (i) For the annual detection of changes, reference points for the base station of the DGPS system were marked. High-resolution digital elevation models (HRDEM) were generated from each dataset of the different years and are compared to each other, resulting in mass balances. (ii) 3D-models of dislocated boulders were reconstructed and parameters (e.g. volume in combination with density measurements, distance and height above present sea-level) were derived for the solution of wave transport equations, which estimate the minimum wave height or velocity that is necessary for boulder movement. (i) Our results show that annual changes are detectable by multi-temporal terrestrial laser scanning. In general, volumetric changes and affected areas are quantifiable and maps of changes can be established. On exposed beach areas, bigger changes were detectable, where seagrass and sand is eroded and gravel accumulated. In opposite, only minor changes for elevated areas are derived. Dislocated boulders on several sites showed no movement. At coastal areas with a high

  7. Status and future of laser scanning, synthetic aperture radar and hyperspectral remote sensing data for forest biomass assessment

    NASA Astrophysics Data System (ADS)

    Koch, Barbara

    2010-11-01

    This is a review of the latest developments in different fields of remote sensing for forest biomass mapping. The main fields of research within the last decade have focused on the use of small footprint airborne laser scanning systems, polarimetric synthetic radar interferometry and hyperspectral data. Parallel developments in the field of digital airborne camera systems, digital photogrammetry and very high resolution multispectral data have taken place and have also proven themselves suitable for forest mapping issues. Forest mapping is a wide field and a variety of forest parameters can be mapped or modelled based on remote sensing information alone or combined with field data. The most common information required about a forest is related to its wood production and environmental aspects. In this paper, we will focus on the potential of advanced remote sensing techniques to assess forest biomass. This information is especially required by the REDD (reducing of emission from avoided deforestation and degradation) process. For this reason, new types of remote sensing data such as fullwave laser scanning data, polarimetric radar interferometry (polarimetric systhetic aperture interferometry, PolInSAR) and hyperspectral data are the focus of the research. In recent times, a few state-of-the-art articles in the field of airborne laser scanning for forest applications have been published. The current paper will provide a state-of-the-art review of remote sensing with a particular focus on biomass estimation, including new findings with fullwave airborne laser scanning, hyperspectral and polarimetric synthetic aperture radar interferometry. A synthesis of the actual findings and an outline of future developments will be presented.

  8. Confocal laser scanning microscopy of liesegang rings in odontogenic cysts: analysis of three-dimensional image reconstruction.

    PubMed

    Scivetti, Michele; Lucchese, Alberta; Crincoli, Vito; Pilolli, Giovanni Pietro; Favia, Gianfranco

    2009-01-01

    Liesegang rings are concentric noncellular lamellar structures, occasionally found in inflammatory tissues. They have been confused with various parasites, algas, calcification, and psammoma bodies. The authors examined Liesegang rings from oral inflammatory cysts by both optical and confocal laser scanning microscopy, and perfomed a three-dimensional reconstruction. These investigations indicate that Liesegang rings are composed of multiple birefringent concentric rings, resulting from a progressive deposition of organic substances, with an unclear pathogenesis.

  9. Photonic crystal fibre enables short-wavelength two-photon laser scanning fluorescence microscopy with fura-2

    NASA Astrophysics Data System (ADS)

    McConnell, Gail; Riis, Erling

    2004-10-01

    We report on a novel and compact reliable laser source capable of short-wavelength two-photon laser scanning fluorescence microscopy based on soliton self-frequency shift effects in photonic crystal fibre. We demonstrate the function of the system by performing two-photon microscopy of smooth muscle cells and cardiac myocytes from the rat pulmonary vein and Chinese hamster ovary cells loaded with the fluorescent calcium indicator fura-2/AM.

  10. Double-wavelength laser scanning microphotometer (DWLSM) for in-vitro hair shaft and surrounding tissue imaging

    NASA Astrophysics Data System (ADS)

    Fedosov, Ivan V.; Zimnyakov, Dmitry A.; Tuchin, Valery V.; Genina, Elina A.; Altshuler, Gregory B.

    2001-05-01

    The double-wavelength laser scanning microphotometer (DWLSM) with high spatial resolution had been developed for in vitro measuring of hair shaft and follicle absorbance. The instrument allows for determining the absorbance distribution across and along hair shaft and follicle. The instrument is based on standard universal binocular microscope. The construction of the instrument and the data processing reduces the influence of the light scattering on the hair and tissue samples.

  11. Morphological Changes Along a Dike Landside Slope Sampled by 4d High Resolution Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Herrero-Huertaa, Mónica; Lindenbergh, Roderik; Ponsioen, Luc; van Damme, Myron

    2016-06-01

    Emergence of light detection and ranging (LiDAR) technology provides new tools for geomorphologic studies improving spatial and temporal resolution of data sampling hydrogeological instability phenomena. Specifically, terrestrial laser scanning (TLS) collects high resolution 3D point clouds allowing more accurate monitoring of erosion rates and processes, and thus, quantify the geomorphologic change on vertical landforms like dike landside slopes. Even so, TLS captures observations rapidly and automatically but unselectively. In this research, we demonstrate the potential of TLS for morphological change detection, profile creation and time series analysis in an emergency simulation for characterizing and monitoring slope movements in a dike. The experiment was performed near Schellebelle (Belgium) in November 2015, using a Leica Scan Station C10. Wave overtopping and overflow over a dike were simulated whereby the loading conditions were incrementally increased and 14 successful scans were performed. The aim of the present study is to analyse short-term morphological dynamic processes and the spatial distribution of erosion and deposition areas along a dike landside slope. As a result, we are able to quantify the eroded material coming from the impact on the terrain induced by wave overtopping which caused the dike failure in a few minutes in normal storm scenarios (Q = 25 l/s/m) as 1.24 m3. As this shows that the amount of erosion is measurable using close range techniques; the amount and rate of erosion could be monitored to predict dike collapse in emergency situation. The results confirm the feasibility of the proposed methodology, providing scalability to a comprehensive analysis over a large extension of a dike (tens of meters).

  12. Automatic Stem Mapping by Merging Several Terrestrial Laser Scans at the Feature and Decision Levels

    PubMed Central

    Liang, Xinlian; Hyyppä, Juha

    2013-01-01

    Detailed up-to-date ground reference data have become increasingly important in quantitative forest inventories. Field reference data are conventionally collected at the sample plot level by means of manual measurements, which are both labor-intensive and time-consuming. In addition, the number of attributes collected from the tree stem is limited. More recently, terrestrial laser scanning (TLS), using both single-scan and multi-scan techniques, has proven to be a promising solution for efficient stem mapping at the plot level. In the single-scan method, the laser scanner is placed at the center of the plot, creating only one scan, and all trees are mapped from the single-scan point cloud. Consequently, the occlusion of stems increases as the range of the scanner increases, depending on the forest's attributes. In the conventional multi-scan method, several scans are made simultaneously inside and outside of the plot to collect point clouds representing all trees within the plot, and these scans are accurately co-registered by using artificial reference targets manually placed throughout the plot. The additional difficulty of applying the multi-scan method is due to the point-cloud registration of several scans not being fully automated yet. This paper proposes a multi-single-scan (MSS) method to map the sample plot. The method does not require artificial reference targets placed on the plot or point-level registration. The MSS method is based on the fully automated processing of each scan independently and on the merging of the stem positions automatically detected from multiple scans to accurately map the sample plot. The proposed MSS method was tested on five dense forest plots. The results show that the MSS method significantly improves the stem-detection accuracy compared with the single-scan approach and achieves a mapping accuracy similar to that achieved with the multi-scan method, without the need for the point-level registration. PMID:23353143

  13. Understanding the structure of Exmoor's peatland ecosystems using laser-scanning technologies

    NASA Astrophysics Data System (ADS)

    Luscombe, D. J.; Anderson, K.; Wetherelt, A.; Grand-Clement, E.; Le-Feuvre, N.; Smith, D.; Brazier, R. E.

    2012-04-01

    Upland blanket peatlands in the UK are of high conservation value and in an intact state, provide important landscape services, such as carbon sequestration and flood attenuation. The drainage of many such wetlands for agricultural reclamation has resulted in changes to upland blanket mire topography, ecology, hydrological processes and carbon fluxes. There is a need for spatially explicit monitoring approaches at peatland sites in the UK as although there has been a national effort to restore drained peat uplands, baseline and post restoration monitoring of changes to ecosystem structure and function is largely absent. Climate change policy and the emerging carbon markets also necessitate the need for enhanced system understanding to inform carbon targets and understand the impacts of restoration. Exmoor is the focus of this research because many areas of upland peat have, in the past, been extensively drained through government "moorland reclamation" programs. A large restoration project funded by South West Water is currently underway in association with Exmoor National Park, The Environment Agency and Natural England. Exmoor also provides an analogue for other westerly peatlands in the British Isles in terms of its climate, ecology and drainage characteristics. Our approach employed airborne LiDAR data gathered by the Environment Agency Geomatics Group coupled with Terrestrial Laser Scanning (TLS) surveys. LiDAR data were processed to produce digital surface models (DSM) of the peatland surface at a 0.5m resolution. These data were further interrogated to separate vegetation structures and geomorphic features such as man-made drainage channels which have damaged the peatland. Over small extents the LiDAR derived DSM surface was then compared to a TLS derived DSM to examine the ability of these models to describe fine scale vegetation and geomorphic structure, which could then be extrapolated to larger spatial extents. Exploration of the data has shown that

  14. Segmentation of Heritage Building by Means of Geometric and Radiometric Components from Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Aitelkadi, K.; Tahiri, D.; Simonetto, E.; Sebari, I.; Polidori, L.

    2013-07-01

    Nowadays, the terrestrial laser scanning represents an integral source of data for cultural heritage 3D storage and access through digital communication tools. The achievement of 3D models requires the implementation of several tasks such as segmentation. Segmentation is the key step during the point cloud processing where all homogeneous areas are identified, which describe a building facade. Usually, a large part of the segmentation approach focuses on the geometric information contained in the point cloud data by exploiting mathematical representation of a parametric surface. However, due to the complexity of the architecture, such segmentation does not suffice. Henceforth, other approaches turn to the use of color and laser intensity components. Although a variety of algorithms have been developed in this sense, problems of over-segmentation or under-segmentation are observed. In this context, we propose a new approach for point cloud segmentation aiming at a more accurate result. This approach relies on all the components of a colored point - both geometric and radiometric - combining the RGB values, laser intensity and geometric data. Our process begins with the extraction of homogeneous planar segments using the RANSAC algorithm. Next, the result is subjected to a radiometric-based segmentation, first through color similarity as one of the homogeneity criteria of a region growing algorithm, then through the use of intensity similarity for segment fusion. Experiments are performed on a facade presenting an example of Moroccan classical architecture located in Casablanca's Medina. Results show the importance of integrating all point cloud components, both geometric and radiometric.

  15. Biochar Erosion in a Temperate Forest Assessed with Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Milenković, Milutin; Bruckman, Viktor; Hollaus, Markus; Pfeifer, Norbert

    2015-04-01

    Biochar amendment in soils is seen as a potential greenhouse gas mitigation strategy. There are a number of examples of successful amendment strategies in agricultural ecosystems, where biochar is mixed with the mineral topsoil by ploughing or similar manipulation techniques. The application in forest ecosystems, however, comes with the limitation that biochar can only be applied directly on the surface. Light-weight biochar particles may be prone to erosion by environmental forces, such as precipitation and wind. We therefore assessed biochar erosion patterns by using Terrestrial Laser Scanning (TLS) in combination with a time-lapse camera on a micro topography scale in a temperate spruce-dominated forest with herbaceous ground vegetation. TLS is a photogrammetric technique that utilizes the laser light detection and ranging (LiDAR) principle to provide high resolution, 3D geometrical information of the object at millimeter scale. A biochar-amended (10 t/ha) plot with the size of ca. 3m x 3m was surveyed with 4 TLS scans taken from each of 4 plot's sides. The acquired scans were co-registered using the professional targets that were installed on the plot's corners. The resulting point cloud was then used as a base for calculating digital terrain model (DTM), to spatially map vegetation heights, vegetation density and roughness. These TLS products were derived by analyzing the geometrical properties of the acquired point cloud. A time-lapse camera was installed during summer 2013, continuously observing the entire plot at 3min intervals. A single, representative, precipitation event in August was selected for a detailed image analysis of biochar particle movement. The analysis showed that areas of notable particle movement correspond to places of flow accumulation simulated from the DTM. This suggests that the very high resolution terrain information can be usefully for planning the biochar amendment on temperate forest ecosystems.

  16. Three-dimensional microstructured tissue scaffolds fabricated by two-photon laser scanning photolithography.

    PubMed

    Hsieh, Tseng Ming; Ng, Chien Wei Benjamin; Narayanan, Karthikeyan; Wan, Andrew C A; Ying, Jackie Y

    2010-10-01

    Current tissue engineering scaffolds fabricated via solvent casting and porogen leaching methods suffer from the lack of control over parameters such as interconnectivity and pore geometry, properties that are a function of the fabrication process. The progress of tissue engineering would thus benefit from the ability to design scaffolds that facilitate cell-cell interactions, and provide mass transfer characteristics necessary for good cell viability and function. In this research, we have developed two-photon laser scanning photolithography (TPLSP) for the fabrication of three-dimensional (3D) microstructured scaffolds with high resolution and fidelity. Modification of our two-photon setup allowed for a scan height of 30 mm and a scan speed of 30 mm/s, making it more amenable to scaffold fabrication. Scaffold production was adapted to computer-aided design (CAD)/computer-aided manufacturing (CAM) technology, to achieve the desired length scales from the submicron level and up. A commercially available photocurable resin that exhibited favorable ultraviolet-visible (UV-vis) transparency, cell compatibility and reproducibility in fabrication was used as the scaffold material. As a proof-of-concept, a microporous, cubic scaffold was fabricated for the purpose of hepatocyte culture. Primary hepatocytes could be uniformly seeded on these scaffolds as observed by confocal fluorescence microscopy. Albumin and urea assays demonstrated that hepatocytes cultured in the 3D scaffold maintained higher levels of liver-specific function over a period of 6 days as compared to the monolayer control. These results may be attributed to the high local concentration of soluble factors within the scaffold, which is important for maintaining the hepatocyte phenotype. Our study illustrates the potential of TPLSP as a new platform for the fabrication of designed, well-controlled, 3D microstructured tissue scaffolds.

  17. Terrestrial laser scanning for detection of landfill gas: a pilot study

    NASA Astrophysics Data System (ADS)

    Reshetyuk, Yuriy; Mårtensson, Stig-Göran

    2014-04-01

    Methane built up in landfills as a result of breaking down of organic materials can be a renewable energy source if it is taken advantage of. The aim of research presented in this paper is to detect landfill gas (that contains methane) by means of terrestrial laser scanning. The hypothesis is that where no surface leakage has been reported, the landfill gas will expand or migrate. Therefore, it is possible to detect it through repeated scanning of the same area and comparison of Digital Terrain Models (DTMs) generated from the point clouds. Only the most significant movements, i.e. vertical, are of interest in this case. During September-November 2011, a small area at Forsbacka landfill in the vicinity of Gävle was scanned 10 times. Epoch-to-epoch comparisons of the resulting DTMs have shown two significant changes (-27 and +19 mm) in elevation of the surface, and it is not impossible that they are caused by migrating landfill gas. The method tested in this study is deemed to be rigorous and accurate for detecting small-scale swell-shrink behaviour of the ground surface (in our case a landfill surface). However, both data processing and interpretation of the results have been considerably complicated by presence of low vegetation (weeds) on the study site, which was dificult to filter away completely from the data. Based on our pilot study, we recommend that a larger area and a longer period of time are chosen to give basis for more grounded conclusions about presence of landfill gas.

  18. Estimating single-tree branch biomass of Norway spruce by airborne laser scanning

    NASA Astrophysics Data System (ADS)

    Hauglin, Marius; Dibdiakova, Janka; Gobakken, Terje; Næsset, Erik

    2013-05-01

    The use of forest biomass for bioenergy purposes, directly or through refinement processes, has increased in the last decade. One example of such use is the utilization of logging residues. Branch biomass constitutes typically a considerable part of the logging residues, and should be quantified and included in future forest inventories. Airborne laser scanning (ALS) is widely used when collecting data for forest inventories, and even methods to derive information at the single-tree level has been described. Procedures for estimation of single-tree branch biomass of Norway spruce using features derived from ALS data are proposed in the present study. As field reference data the dry weight branch biomass of 50 trees were obtained through destructive sampling. Variables were further derived from the ALS echoes from each tree, including crown volume calculated from an interpolated crown surface constructed with a radial basis function. Spatial information derived from the pulse vectors were also incorporated when calculating the crown volume. Regression models with branch biomass as response variable were fit to the data, and the prediction accuracy assessed through a cross-validation procedure. Random forest regression models were compared to stepwise and simple linear least squares models. In the present study branch biomass was estimated with a higher accuracy by the best ALS-based models than by existing allometric biomass equations based on field measurements. An improved prediction accuracy was observed when incorporating information from the laser pulse vectors into the calculation of the crown volume variable, and a linear model with the crown volume as a single predictor gave the best overall results with a root mean square error of 35% in the validation.

  19. Relics of Mining Activities in West Bohemia - Mapping by Airborne Laser Scanning

    NASA Astrophysics Data System (ADS)

    Faltýnová, M.; Pavelka, K.

    2013-07-01

    The part of the Czech Republic - West Bohemia is well known for mining activities, different types of raw materials have been extracted from mines near Jáchymov, Sokolov and other sites since medieval times till today. There are original maps of some sites, as well there is effort of some geologists to find and map relics of mining activities (such as digs visible in terrain) by land survey. The quality of these available maps is unfortunately questionable - due to its age or used methods. Our aim was to find resource useful for searching for these sites, than to use field survey to confirm our findings. We used available digital terrain model (DTM) based on airborne laser scanning (ALS) technology to map relics of mining activities in West Bohemia. The Czech Office for Surveying, Mapping and Cadastre started in 2008 project for terrain mapping using the ALS method. The aim of mapping was to get authentic and detailed DTM of the Czech Republic. About 2/3 of area is currently covered by the DTM based on ALS, this year the mapping should be complete. The dataset is characterised by the density of 1-2 points/m2 and the standard deviation in altitude of model points is up to 30 cm (in forested areas). We had DTM in form of shaded surface for one third of the Czech Republic. The shaded surface enables to highlight terrain break lines, which is suitable for archaeological research. Terrain modifications caused by human activity are characterized by terrain break lines, local tops or pits, which do not fit to local geomorphology. Visual image interpretation of the dataset is in the process.

  20. Nanoparticle flow velocimetry with image phase correlation for confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Jun, Brian H.; Giarra, Matthew; Yang, Haisheng; Main, Russell; Vlachos, Pavlos P.

    2016-10-01

    We present a new particle image correlation technique for resolving nanoparticle flow velocity using confocal laser scanning microscopy (CLSM). The two primary issues that complicate nanoparticle scanning laser image correlation (SLIC)-based velocimetry are (1) the use of diffusion-dominated nanoparticles as flow tracers, which introduce a random decorrelating error into the velocity estimate, and (2) the effects of the scanning laser image acquisition, which introduces a bias error. To date, no study has quantified these errors or demonstrated a means to deal with them in SLIC velocimetry. In this work, we build upon the robust phase correlation (RPC) and existing methods of SLIC to quantify and mitigate these errors. First, we implement an ensemble RPC instead of using an ensemble standard cross-correlation, and develop a SLIC optimal filter that maximizes the correlation strength in order to reliably and accurately detect the correlation peak representing the most probable average displacement of the nanoparticles. Secondly, we developed an analytical model of the SLIC measurement bias error due to image scanning of diffusion-dominated tracer particles. We show that the bias error depends only on the ratio of the mean velocity of the tracer particles to that of the laser scanner and we use this model to correct the induced errors. We validated our technique using synthetic images and experimentally obtained SLIC images of nanoparticle flow through a micro-channel. Our technique reduced the error by up to a factor of ten compared to other SLIC algorithms for the images tested in this study. Moreover, our optimized RPC filter reduces the number of image pairs required for the convergence of the ensemble correlation by two orders of magnitude compared to the standard cross correlation. This feature has broader implications to ensemble correlation methods and should be further explored in depth in the future.

  1. Supervised identification and reconstruction of near-planar geological surfaces from terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    García-Sellés, D.; Falivene, O.; Arbués, P.; Gratacos, O.; Tavani, S.; Muñoz, J. A.

    2011-10-01

    Terrestrial laser scanning is an effective method for digitally capturing outcrops, enabling them to be visualized, analyzed, and revisited in an office environment without the limitations of fieldwork (such as time constraints, weather conditions, outcrop accessibility, repeatability, and poor resolution of measurements). It is common practice in geological interpretation of digital outcrops to use visual identification and manual digitization of pointsets or polylines in order to characterise geological features using 3D CAD-like modules. Other recent and less generic approaches have focused on automated extraction of geological features by using segmentation methods, mostly based on geometric parameters derived from the point cloud, but also aided by attributes captured from the outcrop (intensity, RGB). This paper presents a workflow for the supervised and automated identification and reconstruction of near-planar geological surfaces that have a three-dimensional exposure in the outcrop (typically bedding, fractures, or faults enhanced by differential erosion). The original point cloud is used without modifications, and thus no decimation, smoothing, intermediate triangulation, or gridding are required. The workflow is based on planar regressions carried out for each point in the point cloud, enabling subsequent filtering and classification to be based on orientation, quality of fit, and relative locations of points. A coarse grid preprocessing strategy is implemented to speed up the search for neighboring points, permitting analysis of multimillion point clouds. The surfaces identified are organized into classes according to their orientations and regression quality parameters. These can then be used as seeds for building outcrop reconstructions or further analyzed to investigate their characteristics (geometry, morphology, spacing, dimensions, intersections, etc.). The workflow is illustrated here using a synthetic example and a natural example from a

  2. Laser scanning confocal microscopy characterization of water repellent distribution in a sandstone pore network.

    PubMed

    Zoghlami, Karima; Gómez-Gras, David; Corbella, Mercè; Darragi, Fadila

    2008-11-01

    In the present work, we propose the use of the Laser Scanning Confocal Microscopy (LSCM) to determine the effect of water repellents on rock's pore-network configuration and interconnection. The rocks studied are sandstones of Miocene age, a building material that is commonly found in the architectural heritage of Tunisia. The porosity quantitative data of treated and untreated samples, obtained by mercury porosimetry tests, were compared. The results show a slight decrease in total porosity with the water repellent treatment, which reduced both microporosity and macroporosity. This reduction produced a modification in pore size distribution and a shift of the pore access size mode interval toward smaller pore diameters (from the 30-40 microm to the 20-30 microm intervals). The water repellent was observed in SEM images as a continuous film coating grain surfaces; moreover, it was easily visualized in LSCM, by staining the water repellent with Epodye fluorochrome, and the coating thickness was straightforwardly measured (1.5-2 microm). In fact, the combination of mercury intrusion porosimetry data and LSCM observations suggests that the porosity reduction and the shift of the pore diameter mode were mainly due to the general reduction of pore diameters, but also to the plugging of the smallest pores (less than 3-4 microm in diameter) by the water repellent film. Finally, the LSCM technique enabled the reconstruction of 3D views of the water repellent coating film in the pore network, indicating that its distribution was uniform and continuous over the 100 microm thick sample. The LSCM imaging facilitates the integration and interpretation of mercury porosimetry and SEM data. PMID:18767050

  3. Testing of Land Cover Classification from Multispectral Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Bakuła, K.; Kupidura, P.; Jełowicki, Ł.

    2016-06-01

    Multispectral Airborne Laser Scanning provides a new opportunity for airborne data collection. It provides high-density topographic surveying and is also a useful tool for land cover mapping. Use of a minimum of three intensity images from a multiwavelength laser scanner and 3D information included in the digital surface model has the potential for land cover/use classification and a discussion about the application of this type of data in land cover/use mapping has recently begun. In the test study, three laser reflectance intensity images (orthogonalized point cloud) acquired in green, near-infrared and short-wave infrared bands, together with a digital surface model, were used in land cover/use classification where six classes were distinguished: water, sand and gravel, concrete and asphalt, low vegetation, trees and buildings. In the tested methods, different approaches for classification were applied: spectral (based only on laser reflectance intensity images), spectral with elevation data as additional input data, and spectro-textural, using morphological granulometry as a method of texture analysis of both types of data: spectral images and the digital surface model. The method of generating the intensity raster was also tested in the experiment. Reference data were created based on visual interpretation of ALS data and traditional optical aerial and satellite images. The results have shown that multispectral ALS data are unlike typical multispectral optical images, and they have a major potential for land cover/use classification. An overall accuracy of classification over 90% was achieved. The fusion of multi-wavelength laser intensity images and elevation data, with the additional use of textural information derived from granulometric analysis of images, helped to improve the accuracy of classification significantly. The method of interpolation for the intensity raster was not very helpful, and using intensity rasters with both first and last return

  4. Application of laser scanning microscopy for the analysis of oral biofilm dissolution by different endodontic irrigants

    PubMed Central

    del Carpio-Perochena, Aldo; Bramante, Clovis Monteiro; Hungaro Duarte, Marco Antonio; de Andrade, Flaviana Bombarda; Cavenago, Bruno Cavalini; Villas-Bôas, Marcelo Haas; Ordinola-Zapata, Ronald; Amoroso-Silva, Pablo

    2014-01-01

    Background: Multi-specie biofilms are highly resistant to antimicrobials due to cellular interactions found in them. The purpose of this study was to evaluate, by confocal laser scanning microscopy, the biofilm dissolution effectiveness of different irrigant solutions on biofilms developed on infected dentin in situ. Materials and Methods: A total of 120 bovine dentin specimens infected intraorally (30/group) were treated by the following solutions: 2% of chlorhexidine digluconate, 1%, 2.5% and 5.25% of sodium hypochlorite (NaOCl). The solutions were utilized for 5, 15 and 30 min with 2 experimental volumes 500 μL and 1 mL. All the samples were stained using an acridine orange and the biofilm thickness before (control group) and after the experiments were evaluated, utilizing a confocal microscope at ×40. The Mann-Whitney U and the nom-parametric Kruskal-Wallis Dunns tests were utilized to determine the influence of the volume and to perform the comparisons among the groups respectively. The significance level was set at P < 0.05. Results: Statistical differences were not found among the control and the 2% chlorhexidine digluconate groups at any experimental period (P > 0.05). The biofilm dissolution treated with 1% NaOCl was directly proportional to the exposure time (P < 0.05). The higher values of biofilm dissolution were found in 2.5% and 5.25% NaOCl groups (P > 0.05). Conclusion: The higher exposure times and concentrations of NaOCl were not sufficient to dissolve 100% of the biofilm. However, all NaOCl solutions were more effective than 2% chlorhexidine digluconate to dissolve organic matter. PMID:25225556

  5. A reference-free micro defect visualization using pulse laser scanning thermography and image processing

    NASA Astrophysics Data System (ADS)

    Yang, Jinyeol; Choi, Jaemook; Hwang, Soonkyu; An, Yun-Kyu; Sohn, Hoon

    2016-08-01

    As quality control of micro devices and early detection of micro defects in these devices are becoming increasingly important, the demand for a fast and automated online inspection technique to detect micro defects with high spatial resolution is increasing. In this study, a reference-free micro defect visualization algorithm is developed based on laser scanning thermography to detect micro defects in devices instantaneously and automatically with high spatial resolution. A pulse modulated continuous wave laser generates thermal waves in a target device, and the corresponding thermal responses are recorded by an infrared (IR) camera. When the thermal wave encounters a micro defect, the propagation of the thermal wave is blocked at the interface of the micro defect. The blockage of the thermal wave is detected by the proposed reference-free micro defect visualization algorithm. First, an edge detection algorithm is applied to a raw thermal image obtained at a specific time point to extract the thermal discontinuities formed at the boundaries of the defect. The edge images obtained from all time sequences are then assembled into a single accumulated edge image to accentuate defect-induced thermal disturbances in the form of edge features. Finally, the accumulated edge image is automatically processed using a binary imaging algorithm to visualize the micro defect in the target device. The performance of the proposed reference-free micro defect visualization algorithm is examined using two types of specimens, semiconductor chips and ceramic-epoxy composites. The proposed algorithm successfully diagnoses micro defects ranging from 4 μm to 40 μm in width.

  6. Analysis of dolines using multiple methods applied to airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Bauer, Christian

    2015-12-01

    Delineating dolines is not a straightforward process especially in densely vegetated areas. This paper deals quantitatively with the surface karst morphology of a Miocene limestone occurrence in the Styrian Basin, Austria. The study area is an isolated karst mountain with a smooth morphology (former planation surface of Pliocene age), densely vegetated (mixed forest) and with a surface area of 1.3 km2. The study area is located near the city of Wildon and is named "Wildoner Buchkogel". The aim of this study was to test three different approaches in order to automatically delineate dolines. The data basis for this was a high resolution digital terrain model (DTM) derived from airborne laser scanning (ALS) and with a raster resolution of 1 × 1 m. The three different methods for doline boundary delineation are: (a) the "traditional" method based on the outermost closed contour line; (b) boundary extraction based on a drainage correction algorithm (filling up pits), and (c) boundary extraction based on hydrologic modelling (watershed). Extracted features are integrated in a GIS environment and analysed statistically regarding spatial distribution, shape geometry, elongation direction and volume. The three methods lead to different doline boundaries and therefore investigated parameters show significant variations. The applied methods have been compared with respect to their application purpose. Depending on delineation process, between 118 and 189 dolines could be defined. The high density of surface karst features demonstrates that solutional processes are major factors in the landscape development of the Wildoner Buchkogel. Furthermore the correlation to the landscape evolution of the Grazer Bergland is discussed.

  7. Automatic stem mapping by merging several terrestrial laser scans at the feature and decision levels.

    PubMed

    Liang, Xinlian; Hyyppä, Juha

    2013-01-01

    Detailed up-to-date ground reference data have become increasingly important in quantitative forest inventories. Field reference data are conventionally collected at the sample plot level by means of manual measurements, which are both labor-intensive and time-consuming. In addition, the number of attributes collected from the tree stem is limited. More recently, terrestrial laser scanning (TLS), using both single-scan and multi-scan techniques, has proven to be a promising solution for efficient stem mapping at the plot level. In the single-scan method, the laser scanner is placed at the center of the plot, creating only one scan, and all trees are mapped from the single-scan point cloud. Consequently, the occlusion of stems increases as the range of the scanner increases, depending on the forest's attributes. In the conventional multi-scan method, several scans are made simultaneously inside and outside of the plot to collect point clouds representing all trees within the plot, and these scans are accurately co-registered by using artificial reference targets manually placed throughout the plot. The additional difficulty of applying the multi-scan method is due to the point-cloud registration of several scans not being fully automated yet. This paper proposes a multi-single-scan (MSS) method to map the sample plot. The method does not require artificial reference targets placed on the plot or point-level registration. The MSS method is based on the fully automated processing of each scan independently and on the merging of the stem positions automatically detected from multiple scans to accurately map the sample plot. The proposed MSS method was tested on five dense forest plots. The results show that the MSS method significantly improves the stem-detection accuracy compared with the single-scan approach and achieves a mapping accuracy similar to that achieved with the multi-scan method, without the need for the point-level registration.

  8. Accuracy analysis of height difference models derived from terrestrial laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Glira, Philipp; Briese, Christian; Pfeifer, Norbert; Dusik, Jana; Hilger, Ludwig; Neugirg, Fabian; Baewert, Henning

    2014-05-01

    In many research areas the temporal development of the earth surface topography is investigated for geomorphological analysis (e.g. landslide monitoring). Terrestrial laser scanning (TLS) often is used for this purpose, as it allows a fast and detailed 3d reconstruction of the sampled object. The temporal development of the earth surface usually is investigated on the basis of rasterized data, i.e. digital terrain models (DTM). The difference between two DTMs - the difference model - should preferably correspond to the terrain height changes occurred between the measurement campaigns. Actually, these height differences can be influenced by numerous potential error sources. The height accuracy of each raster cell is affected primarily by (a) the measurement accuracy of the deployed TLS, (b) the terrain topography (e.g. roughness), (c) the registration accuracy, (d) the georeferencing accuracy and (e) the raster interpolation method. Thus, in this contribution, height differences are treated as stochastic variables in order to estimate their precision. For an accurate estimation of the height difference precision a detailed knowledge about the whole processing pipeline (from the raw point clouds to the final difference model) is essential. In this study, first the height difference precision is estimated by a rigorous error propagation. As main result, for each raster cell of the difference model, a corresponding height error is estimated, forming an error map. A statistical hypothesis test is presented in order to judge the significance of a height difference. Furthermore, in order to asses the effect of single factors on the final height difference precision, multivariate statistic methods are applied. This analysis allows the deduction of a simple error propagation model, neglecting error sources with small impact on the final precision. The proposed method is demonstrated by means of TLS data acquired at the Gepatschferner (Tyrol, Austria). This study was carried

  9. Parametric modeling and optimization of laser scanning parameters during laser assisted machining of Inconel 718

    NASA Astrophysics Data System (ADS)

    Venkatesan, K.; Ramanujam, R.; Kuppan, P.

    2016-04-01

    This paper presents a parametric effect, microstructure, micro-hardness and optimization of laser scanning parameters (LSP) on heating experiments during laser assisted machining of Inconel 718 alloy. The laser source used for experiments is a continuous wave Nd:YAG laser with maximum power of 2 kW. The experimental parameters in the present study are cutting speed in the range of 50-100 m/min, feed rate of 0.05-0.1 mm/rev, laser power of 1.25-1.75 kW and approach angle of 60-90°of laser beam axis to tool. The plan of experiments are based on central composite rotatable design L31 (43) orthogonal array. The surface temperature is measured via on-line measurement using infrared pyrometer. Parametric significance on surface temperature is analysed using response surface methodology (RSM), analysis of variance (ANOVA) and 3D surface graphs. The structural change of the material surface is observed using optical microscope and quantitative measurement of heat affected depth that are analysed by Vicker's hardness test. The results indicate that the laser power and approach angle are the most significant parameters to affect the surface temperature. The optimum ranges of laser power and approach angle was identified as 1.25-1.5 kW and 60-65° using overlaid contour plot. The developed second order regression model is found to be in good agreement with experimental values with R2 values of 0.96 and 0.94 respectively for surface temperature and heat affected depth.

  10. Derivation of tree stem structural parameters from static terrestrial laser scanning data

    NASA Astrophysics Data System (ADS)

    Tian, Wei; Lin, Yi; Liu, Yajing; Niu, Zheng

    2014-11-01

    Accurate tree-level characteristic information is increasingly demanded for forest management and environment protection. The cutting-edge remote sensing technique of terrestrial laser scanning (TLS) shows the potential of filling this gap. This study focuses on exploring the methods for deriving various tree stem structural parameters, such as stem position, diameter at breast height (DBH), the degree of stem shrinkage, and the elevation angle and azimuth angle of stem inclination. The data for test was collected with a Leica HDS6100 TLS system in Seurasaari, Southern Finland in September 2010. In the field, the reference positions and DBHs of 100 trees were measured manually. The isolation of individual trees is based on interactive segmentation of point clouds. The estimation of stem position and DBH is based on the schematic of layering and then least-square-based circle fitting in each layer. The slope of robust fit line between the height of each layer and DBH is used to characterize the stem shrinkage. The elevation angle of stem inclination is described by the angle between the ground plane and the fitted stem axis. The angle between the north direction and the fitted stem axis gives the azimuth angle of stem inclination. The estimation of the DBHs performed with R square (R2) of 0.93 and root mean square error (RMSE) of 0.038m.The average angle corresponding to stem shrinkage is -1.86°. The elevation angles of stem inclinations are ranged from 31° to 88.3°. The results have basically validated TLS for deriving multiple structural parameters of stem, which help better grasp tree specialties.

  11. Reconstruction of forest geometries from terrestrial laser scanning point clouds for canopy radiative transfer modelling

    NASA Astrophysics Data System (ADS)

    Bremer, Magnus; Schmidtner, Korbinian; Rutzinger, Martin

    2015-04-01

    The architecture of forest canopies is a key parameter for forest ecological issues helping to model the variability of wood biomass and foliage in space and time. In order to understand the nature of subpixel effects of optical space-borne sensors with coarse spatial resolution, hypothetical 3D canopy models are widely used for the simulation of radiative transfer in forests. Thereby, radiation is traced through the atmosphere and canopy geometries until it reaches the optical sensor. For a realistic simulation scene we decompose terrestrial laser scanning point cloud data of leaf-off larch forest plots in the Austrian Alps and reconstruct detailed model ready input data for radiative transfer simulations. The point clouds are pre-classified into primitive classes using Principle Component Analysis (PCA) using scale adapted radius neighbourhoods. Elongated point structures are extracted as tree trunks. The tree trunks are used as seeds for a Dijkstra-growing procedure, in order to obtain single tree segmentation in the interlinked canopies. For the optimized reconstruction of branching architectures as vector models, point cloud skeletonisation is used in combination with an iterative Dijkstra-growing and by applying distance constraints. This allows conducting a hierarchical reconstruction preferring the tree trunk and higher order branches and avoiding over-skeletonization effects. Based on the reconstructed branching architectures, larch needles are modelled based on the hierarchical level of branches and the geometrical openness of the canopy. For radiative transfer simulations, branch architectures are used as mesh geometries representing branches as cylindrical pipes. Needles are either used as meshes or as voxel-turbids. The presented workflow allows an automatic classification and single tree segmentation in interlinked canopies. The iterative Dijkstra-growing using distance constraints generated realistic reconstruction results. As the mesh representation

  12. Geomorphological Mapping with Terrestrial Laser Scanning and Uav-Based Imaging

    NASA Astrophysics Data System (ADS)

    Tilly, N.; Kelterbaum, D.; Zeese, R.

    2016-06-01

    High-resolution digital elevation models (DEMs) are useful for the detailed mapping of geomorphological features. Nowadays various sensors and platforms are available to collect 3D data. The presented study compares terrestrial laser scanning (TLS) and low-cost unmanned aerial vehicles (UAV)-based imaging in terms of their usability for capturing small-scale surface structures. In October 2014 and June 2015 measurements with both systems were carried out in an episodically water-filled karst depression under pasture farming in the region of Hohenlohe (Southwest Germany). The overall aims were to establish high-resolution DEMs and monitor changes of the relief caused by dissolution and compare the advantages and drawbacks of both systems for such studies. Due to the short time between the campaigns the clear detection of temporal changes was hardly possible. However, the multi-temporal campaigns allowed an extensive investigation of the usability of both sensors under different environmental conditions. In addition to the remote sensing measurements, the coordinates of several positions in the study area were measured with a RTK-DGPS system as independent reference data sets in both campaigns. The TLS- and UAV-derived DEM heights at these positions were validated against the DGPS-derived heights. The accuracy of the TLS-derived values is supported by low mean differences between TLS and DGPS measurements while the UAV-derived models show a weaker performance. In the future years additional simultaneous measurements with both approaches under more similar vegetation conditions are necessary to detect surface movements. Moreover, by investigating the subsurface the interaction of above and below ground processes might be detected.

  13. Improving Canopy Vertical Structure Measurements with Dual-Wavelength Laser Scanning

    NASA Astrophysics Data System (ADS)

    Li, Z.; Strahler, A. H.; Schaaf, C.; Jupp, D. L. B.; Howe, G.; Hewawasam, K.; Chakrabarti, S.; Cook, T.; Paynter, I.; Saenz, E. J.; Yang, X.; Yao, T.

    2015-12-01

    Forest canopy structure regulates radiation interception through the canopy, affects the canopy microclimate, and consequently influences the energy, water, and carbon fluxes between soil, vegetation and atmosphere through its interaction with leaf physiological functioning. To observe vertical canopy forest structure in finer and more accurate detail, we retrieved vertical profiles of leaf and woody components separately with a terrestrial laser scanner, the Dual-Wavelength Echidna Lidar (DWEL). DWEL scans of a hardwood site at the Harvard Forest, Petersham, Massachusetts, USA, in early May and in late September in 2014, revealed the spatial heterogeneity of the canopy vertical structure of the two vegetation components: leaves and woody materials. The DWEL collects simultaneous scans of forests with two lasers at different wavelengths, 1064 nm (NIR) and 1548 nm (SWIR). Power returned from leaves is much lower than from woody materials such as trunks and branches at the SWIR wavelength due to the liquid water absorption by leaves, whereas returned power at the NIR wavelength is similar from both leaves and woody materials. This spectral contrast between leaves and woody materials, along with spatial context information. discriminates leaves and woody materials accurately in 3-D space, thus allowing the measurement of separate leaf and woody area profiles. We also captured the change in the canopy vertical structure over the seven years by a comparison between the current measurements by the DWEL in 2014 and past measurements in 2007 at the same site by the DWEL's predecessor, a single-wavelength terrestrial lidar, the Echidna Validation Instrument. The comparison also demonstrates the advantage of dual-wavelength laser scanning by the DWEL for canopy structure measurements.

  14. Evaluation of Vertical Lacunarity Profiles in Forested Areas Using Airborne Laser Scanning Point Clouds

    NASA Astrophysics Data System (ADS)

    Székely, B.; Kania, A.; Standovár, T.; Heilmeier, H.

    2016-06-01

    The horizontal variation and vertical layering of the vegetation are important properties of the canopy structure determining the habitat; three-dimensional (3D) distribution of objects (shrub layers, understory vegetation, etc.) is related to the environmental factors (e.g., illumination, visibility). It has been shown that gaps in forests, mosaic-like structures are essential to biodiversity; various methods have been introduced to quantify this property. As the distribution of gaps in the vegetation is a multi-scale phenomenon, in order to capture it in its entirety, scale-independent methods are preferred; one of these is the calculation of lacunarity. We used Airborne Laser Scanning point clouds measured over a forest plantation situated in a former floodplain. The flat topographic relief ensured that the tree growth is independent of the topographic effects. The tree pattern in the plantation crops provided various quasi-regular and irregular patterns, as well as various ages of the stands. The point clouds were voxelized and layers of voxels were considered as images for two-dimensional input. These images calculated for a certain vicinity of reference points were taken as images for the computation of lacunarity curves, providing a stack of lacunarity curves for each reference points. These sets of curves have been compared to reveal spatial changes of this property. As the dynamic range of the lacunarity values is very large, the natural logarithms of the values were considered. Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

  15. A cost-effective laser scanning method for mapping stream channel geometry and roughness

    NASA Astrophysics Data System (ADS)

    Lam, Norris; Nathanson, Marcus; Lundgren, Niclas; Rehnström, Robin; Lyon, Steve

    2015-04-01

    In this pilot project, we combine an Arduino Uno and SICK LMS111 outdoor laser ranging camera to acquire high resolution topographic area scans for a stream channel. The microprocessor and imaging system was installed in a custom gondola and suspended from a wire cable system. To demonstrate the systems capabilities for capturing stream channel topography, a small stream (< 2m wide) in the Krycklan Catchment Study was temporarily diverted and scanned. Area scans along the stream channel resulted in a point spacing of 4mm and a point cloud density of 5600 points/m2 for the 5m by 2m area. A grain size distribution of the streambed material was extracted from the point cloud using a moving window, local maxima search algorithm. The median, 84th and 90th percentiles (common metrics to describe channel roughness) of this distribution were found to be within the range of measured values while the largest modelled element was approximately 35% smaller than its measured counterpart. The laser scanning system captured grain sizes between 30mm and 255mm (coarse gravel/pebbles and boulders based on the Wentworth (1922) scale). This demonstrates that our system was capable of resolving both large-scale geometry (e.g. bed slope and stream channel width) and small-scale channel roughness elements (e.g. coarse gravel/pebbles and boulders) for the study area. We further show that the point cloud resolution is suitable for estimating ecohydraulic parameters such as Manning's n and hydraulic radius. Although more work is needed to fine-tune our system's design, these preliminary results are encouraging, specifically for those with a limited operational budget.

  16. Comparison of high resolution terrestrial laser scanning and terrestrial photogrammetry for modeling applications

    NASA Astrophysics Data System (ADS)

    Özdemir, Samed; Bayrak, Temel

    2016-04-01

    3D documentation of cultural heritage and engineering projects is an important matter. These documentation applications, requires highest possible accuracy and detail to represent the actual surface correctly. Terrestrial photogrammetric method which is employed to produce 3D models to day, now can obtain dense point clouds thanks to advancements in computer technology. Terrestrial laser scanners gained popularity in the last decade because of their high capacity and today they are being widely used in many applications. However every application has its own requirements that depend on the type of application, modeling environment, accuracy and budget limitations. This means, for every application highest accuracy instruments are not always best, considering the facts that mentioned before. In this study, laser scanner and terrestrial photogrammetric methods' spatial and model accuracies investigated under various conditions which include measuring targets at different instrument to object distances then investigating the accuracy of these measurements, modeling an irregular shaped surface to compare two surfaces volume and surface areas, at last comparing dimensions of known geometrical shaped small objects. Also terrestrial laser scanners and terrestrial photogrammetric methods most suitable application conditions investigated in terms of cost, time, mobility and accuracy. Terrestrial laser scanner has the ability to, measure distances under cm accuracy and directly measuring 3D world but there is also some drawbacks like sensitive, bulky and expensive equipment. When it comes to terrestrial photogrammetry, it has above cm accuracy, comparatively fast (considering the image acquisition stage), inexpensive but it can be affected by the coarse geometry, surface texture and the environmental lighting. Key Words: Accuracy, Comparison, Model, Terrestrial Photogrammetry, Terrestrial Laser Scanning,.

  17. Algorithm for the Automatic Estimation of Agricultural Tree Geometric Parameters Using Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Hadaś, E.; Borkowski, A.; Estornell, J.

    2016-06-01

    The estimation of dendrometric parameters has become an important issue for the agricultural planning and management. Since the classical field measurements are time consuming and inefficient, Airborne Laser Scanning (ALS) data can be used for this purpose. Point clouds acquired for orchard areas allow to determine orchard structures and geometric parameters of individual trees. In this research we propose an automatic method that allows to determine geometric parameters of individual olive trees using ALS data. The method is based on the α-shape algorithm applied for normalized point clouds. The algorithm returns polygons representing crown shapes. For points located inside each polygon, we select the maximum height and the minimum height and then we estimate the tree height and the crown base height. We use the first two components of the Principal Component Analysis (PCA) as the estimators for crown diameters. The α-shape algorithm requires to define the radius parameter R. In this study we investigated how sensitive are the results to the radius size, by comparing the results obtained with various settings of the R with reference values of estimated parameters from field measurements. Our study area was the olive orchard located in the Castellon Province, Spain. We used a set of ALS data with an average density of 4 points m-2. We noticed, that there was a narrow range of the R parameter, from 0.48 m to 0.80 m, for which all trees were detected and for which we obtained a high correlation coefficient (> 0.9) between estimated and measured values. We compared our estimates with field measurements. The RMSE of differences was 0.8 m for the tree height, 0.5 m for the crown base height, 0.6 m and 0.4 m for the longest and shorter crown diameter, respectively. The accuracy obtained with the method is thus sufficient for agricultural applications.

  18. The Effect of Wind on Tree STEM Parameter Estimation Using Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Vaaja, M. T.; Virtanen, J.-P.; Kurkela, M.; Lehtola, V.; Hyyppä, J.; Hyyppä, H.

    2016-06-01

    The 3D measurement technique of terrestrial laser scanning (TLS) in forest inventories has shown great potential for improving the accuracy and efficiency of both individual tree and plot level data collection. However, the effect of wind has been poorly estimated in the error analysis of TLS tree measurements although it causes varying deformations to the trees. In this paper, we evaluated the effect of wind on tree stem parameter estimation at different heights using TLS. The data consists of one measured Scots pine captured from three different scanning directions with two different scanning resolutions, 6.3 mm and 3.1 mm at 10 m. The measurements were conducted under two different wind speeds, approximately 3 m/s and 9 m/s, as recorded by a nearby weather station of the Finnish Meteorological Institute. Our results show that the wind may cause both the underestimation and overestimation of tree diameter when using TLS. The duration of the scanning is found to have an impact for the measured shape of the tree stem under 9 m/s wind conditions. The results also indicate that a 9 m/s wind does not have a significant effect on the stem parameters of the lower part of a tree (<28% of the tree height). However, as the results imply, the wind conditions should be taken into account more comprehensively in analysis of TLS tree measurements, especially if multiple scans from different positions are registered together. In addition, TLS could potentially be applied to indirectly measure wind speed by observing the tree stem movement.

  19. Automated identification and geometrical features extraction of individual trees from Mobile Laser Scanning data in Budapest

    NASA Astrophysics Data System (ADS)

    Koma, Zsófia; Székely, Balázs; Folly-Ritvay, Zoltán; Skobrák, Ferenc; Koenig, Kristina; Höfle, Bernhard

    2016-04-01

    Mobile Laser Scanning (MLS) is an evolving operational measurement technique for urban environment providing large amounts of high resolution information about trees, street features, pole-like objects on the street sides or near to motorways. In this study we investigate a robust segmentation method to extract the individual trees automatically in order to build an object-based tree database system. We focused on the large urban parks in Budapest (Margitsziget and Városliget; KARESZ project) which contained large diversity of different kind of tree species. The MLS data contained high density point cloud data with 1-8 cm mean absolute accuracy 80-100 meter distance from streets. The robust segmentation method contained following steps: The ground points are determined first. As a second step cylinders are fitted in vertical slice 1-1.5 meter relative height above ground, which is used to determine the potential location of each single trees trunk and cylinder-like object. Finally, residual values are calculated as deviation of each point from a vertically expanded fitted cylinder; these residual values are used to separate cylinder-like object from individual trees. After successful parameterization, the model parameters and the corresponding residual values of the fitted object are extracted and imported into the tree database. Additionally, geometric features are calculated for each segmented individual tree like crown base, crown width, crown length, diameter of trunk, volume of the individual trees. In case of incompletely scanned trees, the extraction of geometric features is based on fitted circles. The result of the study is a tree database containing detailed information about urban trees, which can be a valuable dataset for ecologist, city planners, planting and mapping purposes. Furthermore, the established database will be the initial point for classification trees into single species. MLS data used in this project had been measured in the framework of

  20. Thermal maturity of Tasmanites microfossils from confocal laser scanning fluorescence microscopy

    USGS Publications Warehouse

    Hackley, Paul C.; Kus, Jolanta

    2015-01-01

    We report here, for the first time, spectral properties of Tasmanites microfossils determined by confocal laser scanning fluorescence microscopy (CLSM, using Ar 458 nm excitation). The Tasmanites occur in a well-characterized natural maturation sequence (Ro 0.48–0.74%) of Devonian shale (n = 3 samples) from the Appalachian Basin. Spectral property λmax shows excellent agreement (r2 = 0.99) with extant spectra from interlaboratory studies which used conventional fluorescence microscopy techniques. This result suggests spectral measurements from CLSM can be used to infer thermal maturity of fluorescent organic materials in geologic samples. Spectra of regions with high fluorescence intensity at fold apices and flanks in individual Tasmanites are blue-shifted relative to less-deformed areas in the same body that have lower fluorescence intensity. This is interpreted to result from decreased quenching moiety concentration at these locations, and indicates caution is needed in the selection of measurement regions in conventional fluorescence microscopy, where it is common practice to select high intensity regions for improved signal intensity and better signal to noise ratios. This study also documents application of CLSM to microstructural characterization of Tasmanites microfossils. Finally, based on an extant empirical relation between conventional λmax values and bitumen reflectance, λmax values from CLSM of Tasmanites microfossils can be used to calculate a bitumen reflectance equivalent value. The results presented herein can be used as a basis to broaden the future application of CLSM in the geological sciences into hydrocarbon prospecting and basin analysis.

  1. Real-Time Detection and Tracking of Multiple People in Laser Scan Frames

    NASA Astrophysics Data System (ADS)

    Cui, J.; Song, X.; Zhao, H.; Zha, H.; Shibasaki, R.

    This chapter presents an approach to detect and track multiple people ro bustly in real time using laser scan frames. The detection and tracking of people in real time is a problem that arises in a variety of different contexts. Examples in clude intelligent surveillance for security purposes, scene analysis for service robot, and crowd behavior analysis for human behavior study. Over the last several years, an increasing number of laser-based people-tracking systems have been developed in both mobile robotics platforms and fixed platforms using one or multiple laser scanners. It has been proved that processing on laser scanner data makes the tracker much faster and more robust than a vision-only based one in complex situations. In this chapter, we present a novel robust tracker to detect and track multiple people in a crowded and open area in real time. First, raw data are obtained that measures two legs for each people at a height of 16 cm from horizontal ground with multiple registered laser scanners. A stable feature is extracted using accumulated distribu tion of successive laser frames. In this way, the noise that generates split and merged measurements is smoothed well, and the pattern of rhythmic swinging legs is uti lized to extract each leg. Second, a probabilistic tracking model is presented, and then a sequential inference process using a Bayesian rule is described. A sequential inference process is difficult to compute analytically, so two strategies are presented to simplify the computation. In the case of independent tracking, the Kalman fil ter is used with a more efficient measurement likelihood model based on a region coherency property. Finally, to deal with trajectory fragments we present a concise approach to fuse just a little visual information from synchronized video camera to laser data. Evaluation with real data shows that the proposed method is robust and effective. It achieves a significant improvement compared with existing laser

  2. Quantification of Overnight Movement of Birch (Betula pendula) Branches and Foliage with Short Interval Terrestrial Laser Scanning.

    PubMed

    Puttonen, Eetu; Briese, Christian; Mandlburger, Gottfried; Wieser, Martin; Pfennigbauer, Martin; Zlinszky, András; Pfeifer, Norbert

    2016-01-01

    The goal of the study was to determine circadian movements of silver birch (Petula Bendula) branches and foliage detected with terrestrial laser scanning (TLS). The study consisted of two geographically separate experiments conducted in Finland and in Austria. Both experiments were carried out at the same time of the year and under similar outdoor conditions. Experiments consisted of 14 (Finland) and 77 (Austria) individual laser scans taken between sunset and sunrise. The resulting point clouds were used in creating a time series of branch movements. In the Finnish data, the vertical movement of the whole tree crown was monitored due to low volumetric point density. In the Austrian data, movements of manually selected representative points on branches were monitored. The movements were monitored from dusk until morning hours in order to avoid daytime wind effects. The results indicated that height deciles of the Finnish birch crown had vertical movements between -10.0 and 5.0 cm compared to the situation at sunset. In the Austrian data, the maximum detected representative point movement was 10.0 cm. The temporal development of the movements followed a highly similar pattern in both experiments, with the maximum movements occurring about an hour and a half before (Austria) or around (Finland) sunrise. The results demonstrate the potential of terrestrial laser scanning measurements in support of chronobiology.

  3. Quantification of Overnight Movement of Birch (Betula pendula) Branches and Foliage with Short Interval Terrestrial Laser Scanning

    PubMed Central

    Puttonen, Eetu; Briese, Christian; Mandlburger, Gottfried; Wieser, Martin; Pfennigbauer, Martin; Zlinszky, András; Pfeifer, Norbert

    2016-01-01

    The goal of the study was to determine circadian movements of silver birch (Petula Bendula) branches and foliage detected with terrestrial laser scanning (TLS). The study consisted of two geographically separate experiments conducted in Finland and in Austria. Both experiments were carried out at the same time of the year and under similar outdoor conditions. Experiments consisted of 14 (Finland) and 77 (Austria) individual laser scans taken between sunset and sunrise. The resulting point clouds were used in creating a time series of branch movements. In the Finnish data, the vertical movement of the whole tree crown was monitored due to low volumetric point density. In the Austrian data, movements of manually selected representative points on branches were monitored. The movements were monitored from dusk until morning hours in order to avoid daytime wind effects. The results indicated that height deciles of the Finnish birch crown had vertical movements between -10.0 and 5.0 cm compared to the situation at sunset. In the Austrian data, the maximum detected representative point movement was 10.0 cm. The temporal development of the movements followed a highly similar pattern in both experiments, with the maximum movements occurring about an hour and a half before (Austria) or around (Finland) sunrise. The results demonstrate the potential of terrestrial laser scanning measurements in support of chronobiology. PMID:26973668

  4. Spiral ganglion neuron quantification in the guinea pig cochlea using Confocal Laser Scanning Microscopy compared to embedding methods.

    PubMed

    Wrzeszcz, Antonina; Reuter, Günter; Nolte, Ingo; Lenarz, Thomas; Scheper, Verena

    2013-12-01

    Neuron counting in the cochlea is a crucial but time-consuming operation for which various methods have been developed. To improve simplicity and efficiency, we tested an imaging method of the cochlea, and based on Confocal Laser Scanning Microscopy (CLSM), we visualised Rosenthal's Canal and quantified the spiral ganglion neurons (SGN) within. Cochleae of 8 normal hearing guinea pigs and one implanted with a silicone filament were fixed in paraformaldehyde (PFA), decalcified, dehydrated and cleared in Spalteholz solution. Using the tissue's autofluorescence, CLSM was performed at 100 fold magnification generating z-series stacks of about 20 slices of the modiolus. In 5 midmodiolar slices per cochlea the perimeters of the Rosenthal's Canal were surveyed, representative neuron diameters were measured and the neurons first counted manually and then software-assisted. For comparison, 8 normal hearing guinea pig cochleae were embedded in paraffin and examined similarly. The CLSM method has the advantage that the cochleae remain intact as an organ and keep their geometrical structure. Z-stack creation is nearly fully-automatic and frequently repeatable with various objectives and step sizes and without visible bleaching. The tissue shows minimal or no shrinking artefacts and damage typical of embedding and sectioning. As a result, the cells in the cleared cochleae reach an average diameter of 21 μm and a density of about 18 cells/10,000 μm(2) with no significant difference between the manual and the automatical counts. Subsequently we compared the CLSM data with those generated using the established method of paraffin slides, where the SGN reached a mean density of 9.5 cells/10,000 μm(2) and a mean soma diameter of 13.6 μm. We were able to prove that the semi-automatic CLSM method is a simple and effective technique for auditory neuron count. It provides a high grade of tissue preservation and the automatic stack-generation as well as the counter software reduces

  5. Acousto-optic multiphoton laser scanning microscopy and multiphoton photon counting spectroscopy: Applications and implications for optical neurobiology

    NASA Astrophysics Data System (ADS)

    Iyer, Vijay

    Multiphoton excitation of molecular probes has become an important tool in experimental neurobiology owing to the intrinsic optical sectioning and low light scattering it affords. Using molecular functional indicators, multiphoton excitation allows physiological signals within single neurons to be observed from within living brain tissue. Ideally, it would be possible to record from multiple sites located throughout the elaborately branching dendritic arbors, in order to study the correlations of structure and function both within and across experiments. However, existing multiphoton microscope systems based on scanning mirrors do not allow optical recordings to be obtained from more than a handful of sites simultaneously at the high rates required to capture the fast physiological signals of interest (>100Hz for Ca2+ signals, >1kHz for membrane potential transients). In order to overcome this limitation, two-dimensional acousto-optic deflection was employed, to allow an ultrafast laser beam suited for multiphoton excitation to be rapidly repositioned with low latency (˜15mus). This supports a random-access scanning mode in which the beam can repeatedly visit a succession of user-selected sites of interest within the microscope's field-of-view at high rates, with minimal sacrifice of pixel dwell time. This technique of acousto-optic multiphoton laser scanning microscope (AO-MPLSM) was demonstrated to allow the spatial profile of signals arising in response to physiological stimulation to be rapidly mapped. Means to compensate or avoid problems of dispersion which have hampered AO-MPLSM in the past are presented, with the latter being implemented. Separately, the combination of photon counting detection with multiphoton excitation, termed generally multiphoton photon counting spectroscopy (MP-PCS), was also considered, with particular emphasis on the technique of fluorescence correlation spectroscopy (FCS). MP-PCS was shown to allow information about molecular

  6. Detection of morphological changes in cliff face surrounding a waterfall using terrestrial laser scanning and unmanned aerial system

    NASA Astrophysics Data System (ADS)

    Hayakawa, Yuichi S.; Obanawa, Hiroyuki

    2015-04-01

    Waterfall or bedrock knickpoint appears as an erosional front in bedrock rivers forming deep v-shaped valley downstream. Following the rapid fluvial erosion of waterfall, rockfalls and gravita-tional collapses often occur in surrounding steep cliffs. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatio-temporal distribution have been limited due to the difficulties in direct access to such cliffs if with classical measurement methods. However, for the clarification of geomorphological processes oc-curring in the cliffs, multi-temporal mapping of the cliff face at a high resolution is necessary. Re-mote sensing approaches are therefore suitable for the topographic measurements and detection of changes in such inaccessible cliffs. To achieve accurate topographic mapping of cliffs around a wa-terfall, here we perform multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS). The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff, as well as groundwater outflows from its lower portions. The bedrock is composed of alternate layers of andesite lava and conglomerates. Minor rockfalls in the cliffs are often ob-served by local people. The latest major rockfall occurred in 1986, causing ca. 8-m upstream propa-gation of the waterfall lip. This provides a good opportunity to examine the changes in the surround-ing cliffs following the waterfall recession. Multi-time point clouds were obtained by TLS measure-ment over years, and the three-dimensional changes of the rock surface were detected, uncovering the locus of small rockfalls and gully developments. Erosion seems particularly frequent in relatively weak the conglomerates layer, whereas small rockfalls seems to have occurred in the andesite layers. Also, shadows in the

  7. Use of terrestrial laser scanning for the documentation of quaternary caves

    NASA Astrophysics Data System (ADS)

    Tyszkowski, Sebastian; Kramkowski, Mateusz; Wiśniewska, Daria; Urban, Jan

    2016-04-01

    Due to the nature of their occurrence and genesis, caves in the Polish Lowlands represent a peculiarity of geological heritage, unique on the European scale. They are developed in Quaternary deposits, mostly at the contact of slabs or irregular bodies of cemented glacial or glaciofluvial deposits: conglomerates and sandstones, with unconsolidated deposits, mostly sands, gravels and clays. So far, 20 such caves have been recorded in Polish Lowlands. Most caves are only several meters long, the largest one is over 60 m long. Regardless of their origins, the character of host rocks is the reason that processes leading to their formation are simultaneously the destroying processes. Thus, the studied caves, as well as other caves of this region, are unstable, gradually evolving objects. The changes taking place in them are continuous and intense enough, therefore the documentation of their shape with the greatest possible accuracy and resolution becomes crucial. Such possibility can provide the technique of laser scanning. In 2014 three caves, including one recently discovered, were scanned using the TLS. Measurements of caves and their surroundings were conducted in May and July 2014 with a scanner RIEGL VZ-4000. Point clouds from several scanner positions were combined using the module Multi Station Adjustment in the RiSCAN software. This module allows to connect point clouds from successive positions without any objects of reference. After the merger of point clouds from individual positions and their filtration, a collection of several million points was obtained. The number of points projected on the wall was over 20 000 per m2. The using of TLS enabled to present the morphometric features impossible to obtain using traditional methods. High density of the point clouds allows registering even small details on the cave walls, as well as monitoring leaching, falling, grinding and flaking processes taking place in them. Thus, the most important advantage of the TLS is

  8. Practical aspects of registration the transformation of a river valley by beavers using terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Tyszkowski, Sebastian; Błaszkiewicz, Mirosław; Brykała, Dariusz; Gierszewski, Piotr; Kaczmarek, Halina; Kordowski, Jarosław; Słowiński, Michał

    2016-04-01

    Activity of beavers (Castor fiber) often significantly affects the environment in which they life. The most commonly observed effect of their being in environment is construction of beaver dams and formation a pond upstream. However, in case of a sudden break of a dam and beaver pond drainage, the valley below the dam may also undergo remodelling. The nature and magnitude of these changes depends on the quantity of water and its energy as well as on the geological structure of the valley. The effects of such events can be riverbank erosion, and the deposition of the displaced of erosion products in the form of sandbars or fans. The material can also be accumulated in local depressions or delivered to water bodies. Such events may occur multiple times in the same area. To assess their impact on the environment it is important to quantify the displaced material. The study of such transformations was performed within a small valley of the river of Struga Czechowska (Tuchola Pinewood Forest, Poland). The valley is mainly cut in sands and gravels. Its steep banks are overgrown with bushes and trees. The assessment of changes in morphology were based on the event of the beaver pond drainage of 2015. The study uses the measurements from the terrestrial laser scanning (scanner Riegl VZ-4000). The measurements were performed before and after the event. Each of the two models obtained for comparison was made up of more than 20 measurement stations. Point clouds were joined by Multi-Station Adjustment without placing in the terrain any objects of reference. During measurements attention was paid to the changes in morphology of both riverbed and valley surrounding. The paper presents the example of the recorded changes as well as the measurement procedure. Moreover, the aspects of fieldwork and issues related to post-processing, such as merging, filtering of point clouds and detection of changes, are also presented. This study is a contribution to the Virtual Institute of

  9. Characterizing the geomorphic setting of precariously balanced rocks using terrestrial laser scanning technology

    NASA Astrophysics Data System (ADS)

    Haddad, D. E.; Arrowsmith, R.

    2009-12-01

    Terrestrial laser scanning (TLS) technology is rapidly becoming an effective three-dimensional imaging tool. Precariously balanced rocks are a subset of spheroidally weathered boulders. They are balanced on bedrock pedestals and are formed in upland drainage basins and pediments of exhumed plutons. Precarious rocks are used as negative evidence of earthquake-driven extreme ground motions. Field surveys of PBRs are coupled with cosmogenic radionuclide (CRN) surface exposure dating techniques to determine their exhumation rates. These rates are used in statistical simulations to estimate the magnitudes and recurrences of earthquake-generated extreme ground shaking as a means to physically validate seismic hazard analyses. However, the geomorphic setting of PBRs in the landscape is poorly constrained when interpreting their exhumation rates from CRN surface exposure dates. Are PBRs located on steep or gentle hillslopes? Are they located near drainages or hillslope crests? What geomorphic processes control the spatial distribution of PBRs in a landscape, and where do these processes dominate? Because the fundamental hillslope transport laws are largely controlled by local hillslope gradient and contributing area, the location of a PBR is controlled by the geomorphic agents and their rates acting on it. Our latest efforts involve using a combination of TLS and airborne laser swath mapping (ALSM) to characterize the geomorphic situation of PBRs. We used a Riegl LPM 800i (LPM 321) terrestrial laser scanner to scan a ~1.5 m tall by ~1 m wide precariously balanced rock in the Granite Dells, central Arizona. The PBR was scanned from six positions, and the scans were aligned to a point cloud totaling 3.4M points. We also scanned a ~50 m by ~150 m area covering PBR hillslopes from five scan positions. The resulting 5.5M points were used to create a digital terrain model of precarious rocks and their hillslopes. Our TLS- and ALSM-generated surface models and DEMs provide a

  10. The Echo Cliffs Precariously Balanced Rock; Discovery and Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.; Amidon, W. H.; Bawden, G. W.; Brune, J. N.; Bond, S.; Graves, R. W.; Haddad, D. E.; Limaye, A.; Lynch, D. K.; Phillips, D. A.; Pounders, E.; Rood, D. H.

    2009-12-01

    We investigate a previously undocumented Precariously Balanced Rock (PBR) located above Echo Cliffs in the western Santa Monica Mountains, using Terrestrial Laser Scanning (TLS). We present the merged and aligned point cloud of TLS data (over 42 million points) and photos to document the Echo Cliffs PBR site. We also present our interpretations of the site, of its geomorphic development, and its possible significance for seismic hazards in the Los Angeles region. The rock lies above the ramp in the fault propagation fold structure that has been interpreted by Davis and Namson as an active structure that may pose a major seismic hazard to the Los Angeles area. The Echo Cliffs PBR stands at just over 14 meters in height, so assuming it acts as an inverse pendulum, it has a 3 to 4 second period of oscillation. This period corresponds to the oscillatory period of a 30 to 40 story building. The rock withstood ground motions during the 1994 Northridge earthquake that we estimate to have been 0.2 g (PGA) and 12 cm/sec (PGV) at this site. It is expected that the Echo Cliffs PBR may provide important constraints on scenario ground motions and thereby improve future simulations. We believe that this is the first application of TLS methods on PBR's, and we find that the high resolution provided by TLS allows us to characterize the detailed shape of the PBR itself, as well as key details of the interface between the rock and pedestal at the cm-level. In addition, the cliff band near the PBR and the geomorphic context of the surrounding hill slope area was also scanned at a coarser resolution, providing data that help to understand the processes by which the PBR formed. An advantage of TLS is that it provides an image of the outline of the rock-pedestal contact surface and adjacent non-contacting surfaces. The TLS also helps quantify the effects of shielding on cosmogenic nuclide production, enhancing the accuracy of our surface exposure age dating.

  11. Rock slide deformation measurements with Terrestrial Laser Scanning in inaccessible high mountain areas

    NASA Astrophysics Data System (ADS)

    Fey, C.; Zangerl, C.; Haas, F.; Rutzinger, M.; Sailer, R.; Bremer, M.

    2012-04-01

    In summer 2007 at the "Bliggspitze" (Eastern Alps, 3453 m.a.s.l.), rock and ice fall events testify to increasing slope activities. At the northern slope of the summit a 400 m by 200 m glacier-covered rock mass slab initiated to move downward. The movement causes strong fragmentation of the glacier and the paragneisic rock mass. This process is documented by multi-temporal Airborne Laser Scanning (ALS) digital elevation models (DEMs) (2006/ 2007/ 2008/ 2009/ 2010) and orthophotos (2003/ 2007/ 2009). Between 2006 and 2007 shear displacement of up to 45 m was measured at the main scarp by ALS DEMs. In the following year (2007/2008) the movement rate at the main scarp reduces to 5 m per year. By means of field observations the deformation at the main scarp can be described as a sliding mechanism. In order to understand the landslide kinematics at the lower part of the slope deformation measurements are required. Ongoing rock fall activities at these slope regions preclude field measurements. Furthermore ALS deformation data at the steeply inclined lower part of the slope involve methodically-related uncertainties. In order to get more detailed information about the geometry and the temporal deformation behaviour a Terrestrial Laser Scanner (TLS) is used to scan the lower parts including the toe of the slope. Due to the remoteness, inaccessibly and the large extend of the area of interest the measurement by the TLS is challenging. The test side extends over 500 m width and rises from 2600 to 3200 m.a.s.l.. Long range measurement cause large footprint sizes which lead to lower accuracy in the measured coordinates of the TLS scan. Even in summer single snow patches disturb the reflection of laser beams. Furthermore high rockfall activity precludes the installation of reflective targets in the test side. To minimize shadowing effects, the area was scanned from three scan positions. To register the three scan positions without targets the ICP algorithm of the software Ri

  12. Observations of drainage network change in a recently burned watershed using terrestrial laser scanning

    USGS Publications Warehouse

    Staley, Dennis; Wasklewicz, Thad; Kean, Jason

    2010-01-01

    Wildfire enhances the geomorphic response of a watershed to precipitation events, effectively altering the form of the hillslope and channel drainage network. Typically, drainage networks expand following rainfall on a recently burned watershed. Expansion of drainage networks following wildfire increases in erosion and sediment transport rates, and the probability of flash-flooding and debris-flows at downstream locations. Observations of the response of hillslope and channel drainage to individual precipitation events are vital to unraveling the dynamics of erosion processes in recently burned watersheds. Here, we apply terrestrial laser scanning (TLS) methods to produce digital terrain models (DTMs) of a recently burned watershed at an unprecedented spatial resolution. The DTM data aid the quantification of changes in the hillslope and channel drainage networks at several spatial scales. Two TLS surveys were conducted, one survey between 28-30 September 2008 to document pre-rainfall conditions, and one between 18-21 December 2008, three days after 52 mm of rainfall over a period of 22 hours. A Leica Geosystems ScanStation 2 TLS was used to generate 1 cm resolution DTMs, from which the hillslope and channel drainage networks were derived. The location and magnitude of erosion and deposition for each pixel within the basin was determined by calculating the topographic differences between DTMs. Changes in the drainage network morphology were identified through the analysis of bifurcation ratio, drainage density (including rills), rill length, horizontal migration of rills, width-depth ratios and upstream migration of knickpoints. Comparisons of these measures were made between morphologically distinct sub-basins within the study area, and between surveys. Analyses of bifurcation ratios, and measures of rill position and gullyhead migration indicate an expansion of the rill network and upstream migration of knickpoints. These results suggest that expansion of the

  13. Compact multisensor laser scanning head for processing and monitoring microspot welding

    NASA Astrophysics Data System (ADS)

    Hafez, Moustapha; Julliard, Karin; Grossmann, Sylvain; Olivetta, Lino; Sidler, Thomas C.; Salathe, Rene-Paul; Schwob, Hans-Peter; Blom, Toon; Hoving, Willem

    2000-11-01

    In order to improve the reliability of micro-spot welding of metal parts in production such as e.g. in electron guns for TV picture tubes, real-time information about the evolution of the welding process should be available to allow on-line modification of the laser parameters. Such information can be derived from a set of sensors that are mounted on a laser-scanning head. Different sensors are used to monitor the optical fiber output power to determine the evolution of temperature during the spot welding process, to measure plasma emission and back-reflected laser light. A vision channel and a CCD camera are used to control the position of the laser spot on the parts to be processed. The compact scanning head is composed of a tip/tilt laser scanner, a collimating lens and a focusing lens. The scanner is fast steering, with a bandwidth of 700Hz, and can tilt by +/- 3.5 degree(s) with a repeatability better than 50(mu) rad. The settling time for maximum deflection is less that 10ms. The scanning lens is a newly developed focusing lens designed to replace commercial cumbersome scanning lenses such as F-(theta) lenses, which have large volume, weight and price. This lens is based on the well-known Cooke triplet design and guarantees a constant shape of the spot all over the scan surface and is specially well suited for high power beam delivery. The scan field achieved by the system is limited to 25mm x 25mm. The laser used for this application is a pulsed Nd:YAG laser delivered by an optical fiber to the optical head. However, the system can be adapted to different types of lasers. Laser micro-spot welding on copper substrate has been performed in the frame of the Brite-Euram project MAIL. Smaller tolerances (a factor of 2 less) on the spot diameters were obtained in the case of a sensor controlled operation compared to the case where sensor control is not used.

  14. 3D change detection at street level using mobile laser scanning point clouds and terrestrial images

    NASA Astrophysics Data System (ADS)

    Qin, Rongjun; Gruen, Armin

    2014-04-01

    Automatic change detection and geo-database updating in the urban environment are difficult tasks. There has been much research on detecting changes with satellite and aerial images, but studies have rarely been performed at the street level, which is complex in its 3D geometry. Contemporary geo-databases include 3D street-level objects, which demand frequent data updating. Terrestrial images provides rich texture information for change detection, but the change detection with terrestrial images from different epochs sometimes faces problems with illumination changes, perspective distortions and unreliable 3D geometry caused by the lack of performance of automatic image matchers, while mobile laser scanning (MLS) data acquired from different epochs provides accurate 3D geometry for change detection, but is very expensive for periodical acquisition. This paper proposes a new method for change detection at street level by using combination of MLS point clouds and terrestrial images: the accurate but expensive MLS data acquired from an early epoch serves as the reference, and terrestrial images or photogrammetric images captured from an image-based mobile mapping system (MMS) at a later epoch are used to detect the geometrical changes between different epochs. The method will automatically mark the possible changes in each view, which provides a cost-efficient method for frequent data updating. The methodology is divided into several steps. In the first step, the point clouds are recorded by the MLS system and processed, with data cleaned and classified by semi-automatic means. In the second step, terrestrial images or mobile mapping images at a later epoch are taken and registered to the point cloud, and then point clouds are projected on each image by a weighted window based z-buffering method for view dependent 2D triangulation. In the next step, stereo pairs of the terrestrial images are rectified and re-projected between each other to check the geometrical

  15. Rockfall trajectory modelling by the integration of Digital Terrestrial Photogrammetry, Laser Scanning and GIS

    NASA Astrophysics Data System (ADS)

    Francioni, Mirko; Salvini, Riccardo; Riccucci, Silvia; Guastaldi, Enrico; Ortolano, Fabrizio; Bonciani, Filippo; Callegari, Ivan; Fantozzi, Pierlorenzo

    2010-05-01

    The present paper describes the runout analysis of rocky unstable blocks on the slope, 500 m wide and 600 m high, overhanging the railroad line Domodossola - Iselle, Italy. In addition to the traditional geological, geomorphological and engineering-geological surveys, DTP (Digital Terrestrial Photogrammetry) by means of an helicopter was used to perform a detailed analysis of rocky blocks sited in inaccessible areas. In order to accomplish the analysis, DTP was combined with LS (Laser Scanning) to build the DDSM (Digital Dense Surface Model) of the slope. Aim of the work is the assessment of the rockfalls potentially dangerous for the railroad line, the assessment of the efficiency of existing protection measures and the prompt of mitigation strategies and monitoring. In order to collect the exact position and size of blocks and wedges, a digital interpretation of stereopairs coming from DTP has been carried out. The photointerpretation has been used to realize the land cover map (ex. outcropping rock, soil covered by vegetation) and to recognize the mitigation and protection measures already installed. Starting from blocks position the DDSM has allowed to determine the probable trajectories of rockfall along the slope. These have been calculated by means of a GIS procedure by the use of the ArcHydro module of EsriTM ArcMap assuming a correspondence between probable trajectories and flowdirection. The morphologic profile of rock falling paths has been obtained by the interpolation of 3D points coming from a properly procedure developed inside EsriTM Arcinfo Workstation environment integrated with the Easy Profiler tool of EsriTM ArcMap. The physical-mechanical characteristics of blocks, the morphologic profile, the land cover and the location of the protection barriers (classified according to the height - from 2 to 4 m - and to the preservation status), have been used as input data in RocFall2D (RoscienceTM) software to calculate the runout analysis. Local slope

  16. Mapping of local-scale flooding on vegetated floodplains from radiometrically calibrated airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Malinowski, Radosław; Höfle, Bernhard; König, Kristina; Groom, Geoffrey; Schwanghart, Wolfgang; Heckrath, Goswin

    2014-05-01

    The agricultural use of riverine lowlands is often dependent on complex hydrological regimes including localized flooding. Knowledge about spatio-temporal inundation patterns enables a better understanding of the state of agricultural areas in lowlands and provides valuable and objective information on land suitability for land use administration and environmental planning. Data from Airborne Laser Scanning (ALS), also referred to as LiDAR, have become one of the most important sources of elevation data during the last two decades. Recently, geometric and radiometric attributes of ALS have also been explored for analysing the extent of water surfaces. Thus, the main objective of this work is to develop a method for mapping the spatial extent of floodplain inundation by means of remote sensing data. Our study focusses on analysing floodwaters partly covered by some vegetation, which is a major challenge in flood mapping. We hypothesize that ALS data due to its high sampling density and high rate of canopy penetration can effectively be used for floodwater detection in such areas. This research utilizes full-waveform ALS data with an average point density of 20 points/m2 obtained for an area of ca. 8 km2 of the Nørreå River valley in Jutland, Denmark. The study area is characterised by the presence of improved or semi-improved grasslands (meadows and pasture), few arable fields, irregularly scattered group of trees and bushes, and an extensive ditch network. Our approach is based on an inspection of properties of single laser points with regard to water vs. vegetation coverage within the laser footprint, which is compared with very detailed field reference data. Exploratory analysis and classification of ALS data were preceded by radiometric calibration of point cloud data, utilizing in situ measurements of reference targets reflectance. The resulting calibration derivatives provide very stable estimates of surface characteristics and are used as the main input in

  17. Tension zones of deep-seated rockslides revealed by thermal anomalies and airborne laser scan data

    NASA Astrophysics Data System (ADS)

    Baroň, Ivo; Bečkovský, David; Gajdošík, Juraj; Opálka, Filip; Plan, Lukas; Winkler, Gerhard

    2015-04-01

    Open cracks, tension fractures and crevice caves are important diagnostic features of gravitationally deformed slopes. When the cracks on the upper part of the slope open to the ground surface, they transfer relatively warm and buoyant air from the underground in cold seasons and thus could be detected by the infrared thermography (IRT) as warmer anomalies. Here we present two IRT surveys of deep-seated rockslides in Austria and the Czech Republic. We used thermal imaging cameras Flir and Optris, manipulated manually from the ground surface and also from unmanned aerial vehicle and piloted ultralight-plane platforms. The surveys were conducted during cold days of winter 2014/2015 and early in the morning to avoid the negative effect of direct sunshine. The first study site is the Bad Fischau rockslide in the southern part of the Vienna Basin (Austria). It was firstly identified by the morphostructural analysis of 1-m digital terrain model from the airborne laser scan data. The rockslide is superimposed on, and closely related to the active marginal faults of the Vienna basin, which is a pull apart structure. There is the 80-m-deep Eisenstein Show Cave situated in the southern lateral margin of the rockslide. The cave was originally considered to be purely of hydrothermal (hypogene) karstification; however its specific morphology and position within the detachment zone of the rockslide suggests its relation to gravitational slope-failure. The IRT survey revealed the Eisenstein Cave at the ground surface and also several other open cracks and possible cleft caves along the margins, headscarp, and also within the body of the rockslide. The second surveyed site was the Kněhyně rockslide in the flysch belt of the Outer Western Carpathians in the eastern Czech Republic. This deep-seated translational rockslide formed about eight known pseudokarst crevice caves, which reach up to 57 m in depth. The IRT survey recognized several warm anomalies indicating very deep

  18. Evaluation of the use of laser scanning to create key models for 3D printing separate from and augmenting visible light sensing

    NASA Astrophysics Data System (ADS)

    Straub, Jeremy; Kerlin, Scott

    2016-05-01

    The illicit creation of 3D printed keys is problematic as it can allow intruders nearly undetectable access to secure facilities. Prior work has discussed how keys can be created using visible light sensing. This paper builds on this work by evaluating the utility of keys produced with laser scanning. The quality of the model produced using a structured laser scanning approach is compared to the quality of a model produced using a similarly robust visible light sensing approach.

  19. 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.

  20. Airborne Laser Scanning - based vegetation classification in grasslands: a feasibility study

    NASA Astrophysics Data System (ADS)

    Zlinszky, András; Vári, Ágnes; Deák, Balázs; Mücke, Werner; Székely, Balázs

    2013-04-01

    Airborne Laser Scanning is traditionally used for topography mapping, exploiting its ability to map terrain elevation under vegetation cover. Parallel to this, the application of ALS for vegetation classification and mapping of ecological variables is rapidly emerging. Point clouds surveyed by ALS provide accurate representations of vegetation structure and are therefore considered suitable for mapping vegetation classes as long as their vertical structure is characteristic. For this reason, most ALS-based vegetation mapping studies have been carried out in forests, with some rare applications for shrublands or tall grass vegetation such as reeds. The use of remote-sensing derived vegetation maps is widespread in ecological research and is also gaining importance in practical conservation. There is an increasing demand for reliable, high-resolution datasets covering large protected areas. ALS can provide both the coverage and the high resolution, and can prove to be an economical solution due to the potential for automatic processing and the wide range of uses that allows spreading costs. Grasslands have a high importance in nature conservation as due to the drastical land use changes (arable lands, afforestation, fragmentation by linear structures) in the last centuries the extent of these habitats have been considerably reduced. Among the habitat types protected by the Habitat Directive of the Natura 2000 system, several grassland habitat types (e.g. hay meadows, dry grasslands harbouring rare Orchid species) have special priority for conservation. For preserving these habitat types application of a proper management - including mowing or grazing - has a crucial role. Therefore not only the mapping of the locations of habitats but the way of management is needed for representing the natural processes. The objective of this study was to test the applicability of airborne laser scanning for ecological vegetation mapping in and around grasslands. The study site is

  1. Multiplex fluorescence in situ hybridization (M-FISH) and confocal laser scanning microscopy (CLSM) to analyze multispecies oral biofilms.

    PubMed

    Karygianni, Lamprini; Hellwig, Elmar; Al-Ahmad, Ali

    2014-01-01

    Multiplex fluorescence in situ hybridization (M-FISH) constitutes a favorable microbiological method for the analysis of spatial distribution of highly variable phenotypes found in multispecies oral biofilms. The combined use of confocal laser scanning microscopy (CLSM) produces high-resolution three-dimensional (3D) images of individual bacteria in their natural environment. Here, we describe the application of M-FISH on early (Streptococcus spp., Actinomyces naeslundii) and late colonizers (Fusobacterium nucleatum, Veillonella spp.) of in situ-formed oral biofilms, the acquisition of CLSM images, as well as the qualitative and quantitative analysis of these digitally obtained and processed images.

  2. Shrinking of ultrathin polyelectrolyte multilayer capsules upon annealing: A confocal laser scanning microscopy and scanning force microscopy study

    NASA Astrophysics Data System (ADS)

    Leporatti, S.; Gao, C.; Voigt, A.; Donath, E.; Möhwald, H.

    Heating-induced morphological changes of micrometer size capsules prepared by step-wise deposition of oppositely charged polyelectrolytes onto melamine formaldehyde (MF) latex particles and biological cells with subsequent dissolution of the core have been investigated by confocal laser scanning microscopy (CLSM) and scanning force microscopy (SFM). For poly(styrenesulfonate-Na salt)/poly(allylamine hydrochloride) polyelectrolyte capsules a remarkable heating-induced shrinking is observed. An increase of the wall thickness corresponding to the capsule diameter decrease is found. The morphology of these microcapsules after temperature treatment is characterized. The thickening of the polyelectrolyte multilayer is interpreted in terms of a configurational entropy increase via polyanion-polycation bond rearrangement.

  3. Use of terrestrial laser scanning to characterize rock glacier surface morphology and deformation, Handcart Gulch, Colorado

    NASA Astrophysics Data System (ADS)

    Cuddus, Y.; Caine, J. S.

    2012-12-01

    While there has been extensive, recent research on the kinematics of rock glaciers, few studies have been able to examine surface deformation and strain utilizing terrestrial laser scanning (TLS). TLS captures a high precision, three-dimensional point cloud of X, Y, Z data. We scanned a portion of the Handcart Gulch Rock Glacier (HRG) surface at centimeter scale resolution (standard deviation of 0.64 cm). Although the origins of rock glacier formation and subsequent kinematics are poorly understood, the general consensus is that periglacial rock glaciers are a type of mass-driven permafrost that moves on the order of tens of cm per year. Velocity near the surface is thought to be faster than at depth, producing ridge- or moraine-like structures possibly formed by near-surface, compressional buckling. The HRG, located in Pike National Forest just below the Continental Divide, is multi-lobed and composed of hydrothermally altered Proterozoic metamorphic rock. In addition to commonly observed "compressional ridges", the rock glacier surface shows a number of scarp-like discontinuities that may be indicative of extension. The rock glacier surface has limited vegetative cover and a thin, but laterally extensive, layer of unidentified black lichen and lesser amounts of green Rhizocarpon lichen. The curviplanar scarps are up to about 4 m in height and are marked by discrete discontinuities that cut the lichen-covered rock glacier surface, revealing steeply dipping (> 35°) faces that are not covered with lichen. The lichen-covered surface appears to have been displaced, top-down in the direction of the maximum topographic gradient, and along the relatively lichen-free scarps thus resembling normal faults. Lichenometry is a useful method for providing a relative dating of rock glacial movement. Rhizocarpon is commonly used for dating due to its well documented, slow growth rate and ease of identification. After a century of growth the maximum diameter of Front Range

  4. Semi-automatic mapping of cultural heritage from airborne laser scanning using deep learning

    NASA Astrophysics Data System (ADS)

    Due Trier, Øivind; Salberg, Arnt-Børre; Holger Pilø, Lars; Tonning, Christer; Marius Johansen, Hans; Aarsten, Dagrun

    2016-04-01

    This paper proposes to use deep learning to improve semi-automatic mapping of cultural heritage from airborne laser scanning (ALS) data. Automatic detection methods, based on traditional pattern recognition, have been applied in a number of cultural heritage mapping projects in Norway for the past five years. Automatic detection of pits and heaps have been combined with visual interpretation of the ALS data for the mapping of deer hunting systems, iron production sites, grave mounds and charcoal kilns. However, the performance of the automatic detection methods varies substantially between ALS datasets. For the mapping of deer hunting systems on flat gravel and sand sediment deposits, the automatic detection results were almost perfect. However, some false detections appeared in the terrain outside of the sediment deposits. These could be explained by other pit-like landscape features, like parts of river courses, spaces between boulders, and modern terrain modifications. However, these were easy to spot during visual interpretation, and the number of missed individual pitfall traps was still low. For the mapping of grave mounds, the automatic method produced a large number of false detections, reducing the usefulness of the semi-automatic approach. The mound structure is a very common natural terrain feature, and the grave mounds are less distinct in shape than the pitfall traps. Still, applying automatic mound detection on an entire municipality did lead to a new discovery of an Iron Age grave field with more than 15 individual mounds. Automatic mound detection also proved to be useful for a detailed re-mapping of Norway's largest Iron Age grave yard, which contains almost 1000 individual graves. Combined pit and mound detection has been applied to the mapping of more than 1000 charcoal kilns that were used by an iron work 350-200 years ago. The majority of charcoal kilns were indirectly detected as either pits on the circumference, a central mound, or both

  5. Geodetic Imaging for Rapid Assessment of Earthquakes: Airborne Laser Scanning (ALS)

    NASA Astrophysics Data System (ADS)

    Carter, W. E.; Shrestha, R. L.; Glennie, C. L.; Sartori, M.; Fernandez-Diaz, J.; National CenterAirborne Laser Mapping Operational Center

    2010-12-01

    To the residents of an area struck by a strong earthquake quantitative information on damage to the infrastructure, and its attendant impact on relief and recovery efforts, is urgent and of primary concern. To earth scientists a strong earthquake offers an opportunity to learn more about earthquake mechanisms, and to compare their models with the real world, in hopes of one day being able to accurately predict the precise locations, magnitudes, and times of large (and potentially disastrous) earthquakes. Airborne laser scanning (also referred to as airborne LiDAR or Airborne Laser Swath Mapping) is particularly well suited for rapid assessment of earthquakes, both for immediately estimating the damage to infrastructure and for providing information for the scientific study of earthquakes. ALS observations collected at low altitude (500—1000m) from a relatively slow (70—100m/sec) aircraft can provide dense (5—15 points/m2) sets of surface features (buildings, vegetation, ground), extending over hundreds of square kilometers with turn around times of several hours to a few days. The actual response time to any given event depends on several factors, including such bureaucratic issues as approval of funds, export license formalities, and clearance to fly over the area to be mapped, and operational factors such as the deployment of the aircraft and ground teams may also take a number of days for remote locations. Of course the need for immediate mapping of earthquake damage generally is not as urgent in remote regions with less infrastructure and few inhabitants. During August 16-19, 2010 the National Center for Airborne Laser Mapping (NCALM) mapped the area affected by the magnitude 7.2 El Mayor-Cucapah Earthquake (Northern Baja California Earthquake), which occurred on April 4, 2010, and was felt throughout southern California, Arizona, Nevada, and Baja California North, Mexico. From initial ground observations the fault rupture appeared to extend 75 km

  6. An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

    NASA Astrophysics Data System (ADS)

    Kania, Adam; Székely, Balázs

    2016-04-01

    Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas

  7. Intercomparison of Terrestrial Laser Scanning Instruments for Assessing Forested Ecosystems: A Brisbane Field Experiment

    NASA Astrophysics Data System (ADS)

    Armston, J.; Newnham, G.; Strahler, A. H.; Schaaf, C.; Danson, M.; Gaulton, R.; Zhang, Z.; Disney, M.; Sparrow, B.; Phinn, S. R.; Schaefer, M.; Burt, A.; Counter, S.; Erb, A.; Goodwin, N.; Hancock, S.; Howe, G.; Johansen, K.; Li, Z.; Lollback, G.; Martel, J.; Muir, J.; Paynter, I.; Saenz, E.; Scarth, P.; Tindall, D.; Walker, L.; Witte, C.; Woodgate, W.; Wu, S.

    2013-12-01

    themes include retrieval of leaf area index and related parameters; retrieval of tree diameters, above-ground biomass, and height; approaches to calibration; waveform vs. discrete return data; value of dual wavelength data; ray tracing simulations driven by scanning; and others. This effort was initiated as an activity of the Terrestrial Laser Scanning International Interest Group. The primary objective of this international collaboration is to advance the understanding and application of TLS to forest management and inventory, rapid and automated measurement of vegetation structure parameters, monitoring vegetation dynamics, calibration and validation of large area above-ground biomass mapping, and the development of new low-cost portable scanners to enable wider application of these technologies. Immediate application of the data sets and techniques developed will be through national collaborative research programs, such as NEON and TERN, which enable the techniques and infrastructure developed to be applied consistently. These collaborations and the data and techniques developed and shared openly are essential to enable consistent production of forest structural property maps in science and management applications.

  8. Rock and stone weathering at Citadel fortifications, Gozo (Malta): benefits from terrestrial laser scanning combined with conventional investigations

    NASA Astrophysics Data System (ADS)

    Tapete, D.; Gigli, G.; Mugnai, F.; Vannocci, P.; Pecchioni, E.; Morelli, S.; Fanti, R.; Casagli, N.

    2012-04-01

    Military architecture heritage is frequently built on rock masses affected by slope instability and weathering processes, which progressively undermine the foundations and cause collapses and toppling of the masonries. The latter can be also weakened by alteration of the stone surfaces, as a consequence of the interactions with the local environmental conditions. These conservation issues are emphasized for those sites, whose susceptibility to structural damages is also due to the similarity between the lithotypes constituting the geologic substratum and the construction materials. Effective solutions for the protection from such a type of phenomena can be achieved if the whole "rock mass - built heritage system" is analyzed. In this perspective, we propose a new approach for the study of the weathering processes affecting historic hilltop sites, taking benefits from the combination of terrestrial laser scanning (TLS) and conventional investigations, the latter including geotechnical and minero-petrographic analyses. In particular, the results here presented were obtained from specific tests on the fortifications of Citadel, Gozo (Malta), performed in co-operation with the Restoration Unit, Works Division, Maltese Ministry for Resources and Rural Affairs and the private company Politecnica Ingegneria e Architettura. The Citadel fortifications are built at the top of a relatively stiff and brittle limestone plate, formed by Upper Coralline Limestone (UCL) and overlying a thick Blue Clay (BC) layer. Differential weathering creates extensively fractured ledges on the cap and erosion niches in the strata beneath, thereby favouring block detachment, even rockfall events, such as the last one occurred in 2001. The locally quarried Globigerina Limestone (GL), historically employed in restoration masonries, is also exposed to alveolization and powdering, and several collapses damaged the underwalling interventions. Since the erosion pattern distribution suggested a

  9. An endolithic microbial community in dolomite rock in central Switzerland: characterization by reflection spectroscopy, pigment analyses, scanning electron microscopy, and laser scanning microscopy.

    PubMed

    Horath, T; Neu, T R; Bachofen, R

    2006-04-01

    A community of endolithic microorganisms dominated by phototrophs was found as a distinct band a few millimeters below the surface of bare exposed dolomite rocks in the Piora Valley in the Alps. Using in situ reflectance spectroscopy, we detected chlorophyll a (Chl a), phycobilins, carotenoids, and an unknown type of bacteriochlorophyll-like pigment absorbing in vivo at about 720 nm. In cross sections, the data indicated a defined distribution of different groups of organisms perpendicular to the rock surface. High-performance liquid chromatography analyses of pigments extracted with organic solvents confirmed the presence of two types of bacteriochlorophylls besides chlorophylls and various carotenoids. Spherical organisms of varying sizes and small filaments were observed in situ with scanning electron microscopy and confocal laser scanning microscopy (one- and two-photon technique). The latter allowed visualization of the distribution of phototrophic microorganisms by the autofluorescence of their pigments within the rock. Coccoid cyanobacteria of various sizes predominated over filamentous ones. Application of fluorescence-labeled lectins demonstrated that most cyanobacteria were embedded in an exopolymeric matrix. Nucleic acid stains revealed a wide distribution of small heterotrophs. Some biological structures emitting a green autofluorescence remain to be identified. PMID:16598629

  10. Characterization of atopic skin and the effect of a hyperforin-rich cream by laser scanning microscopy.

    PubMed

    Meinke, Martina C; Richter, Heike; Kleemann, Anke; Lademann, Juergen; Tscherch, Kathrin; Rohn, Sascha; Schempp, Christoph M

    2015-05-01

    Atopic dermatitis (AD) is a multifactorial inflammatory skin disease that affects both children and adults in an increasing manner. The treatment of AD often reduces subjective skin parameters, such as itching, dryness, and tension, but the inflammation cannot be cured. Laser scanning microscopy was used to investigate the skin surface, epidermal, and dermal characteristics of dry and atopic skin before and after treatment with an ointment rich in hyperforin, which is known for its anti-inflammatory effects. The results were compared to subjective parameters and transepidermal water loss, stratum corneum moisture, and stratum corneum lipids. Using biophysical methods, in particular laser scanning microscopy, it was found that atopic skin has distinct features compared to healthy skin. Treatment with a hyperforin-rich ointment resulted in an improvement of the stratum corneum moisture, skin surface dryness, skin lipids, and the subjective skin parameters, indicating that the barrier is stabilized and improved by the ointment. But in contrast to the improved skin surface, the inflammation in the deeper epidermis/dermis often continues to exist. This could be clearly shown by the reflectance confocal microscopy (RCM) measurements. Therefore, RCM measurements could be used to investigate the progress in treatment of atopic dermatitis.

  11. Terrestrial and aerial laser scanning data integration using wavelet analysis for the purpose of 3D building modeling.

    PubMed

    Kedzierski, Michal; Fryskowska, Anna

    2014-07-07

    Visualization techniques have been greatly developed in the past few years. Three-dimensional models based on satellite and aerial imagery are now being enhanced by models generated using Aerial Laser Scanning (ALS) data. The most modern of such scanning systems have the ability to acquire over 50 points per square meter and to register a multiple echo, which allows the reconstruction of the terrain together with the terrain cover. However, ALS data accuracy is less than 10 cm and the data is often incomplete: there is no information about ground level (in most scanning systems), and often around the facade or structures which have been covered by other structures. However, Terrestrial Laser Scanning (TLS) not only acquires higher accuracy data (1-5 cm) but is also capable of registering those elements which are incomplete or not visible using ALS methods (facades, complicated structures, interiors, etc.). Therefore, to generate a complete 3D model of a building in high Level of Details, integration of TLS and ALS data is necessary. This paper presents the wavelet-based method of processing and integrating data from ALS and TLS. Methods of choosing tie points to combine point clouds in different datum will be analyzed.

  12. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors.

    PubMed

    Yuan, Liang Leon; Herman, Peter R

    2016-01-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems.

  13. Segmentation of Planar Surfaces from Laser Scanning Data Using the Magnitude of Normal Position Vector for Adaptive Neighborhoods.

    PubMed

    Kim, Changjae; Habib, Ayman; Pyeon, Muwook; Kwon, Goo-rak; Jung, Jaehoon; Heo, Joon

    2016-01-01

    Diverse approaches to laser point segmentation have been proposed since the emergence of the laser scanning system. Most of these segmentation techniques, however, suffer from limitations such as sensitivity to the choice of seed points, lack of consideration of the spatial relationships among points, and inefficient performance. In an effort to overcome these drawbacks, this paper proposes a segmentation methodology that: (1) reduces the dimensions of the attribute space; (2) considers the attribute similarity and the proximity of the laser point simultaneously; and (3) works well with both airborne and terrestrial laser scanning data. A neighborhood definition based on the shape of the surface increases the homogeneity of the laser point attributes. The magnitude of the normal position vector is used as an attribute for reducing the dimension of the accumulator array. The experimental results demonstrate, through both qualitative and quantitative evaluations, the outcomes' high level of reliability. The proposed segmentation algorithm provided 96.89% overall correctness, 95.84% completeness, a 0.25 m overall mean value of centroid difference, and less than 1° of angle difference. The performance of the proposed approach was also verified with a large dataset and compared with other approaches. Additionally, the evaluation of the sensitivity of the thresholds was carried out. In summary, this paper proposes a robust and efficient segmentation methodology for abstraction of an enormous number of laser points into plane information. PMID:26805849

  14. Segmentation of Planar Surfaces from Laser Scanning Data Using the Magnitude of Normal Position Vector for Adaptive Neighborhoods.

    PubMed

    Kim, Changjae; Habib, Ayman; Pyeon, Muwook; Kwon, Goo-rak; Jung, Jaehoon; Heo, Joon

    2016-01-22

    Diverse approaches to laser point segmentation have been proposed since the emergence of the laser scanning system. Most of these segmentation techniques, however, suffer from limitations such as sensitivity to the choice of seed points, lack of consideration of the spatial relationships among points, and inefficient performance. In an effort to overcome these drawbacks, this paper proposes a segmentation methodology that: (1) reduces the dimensions of the attribute space; (2) considers the attribute similarity and the proximity of the laser point simultaneously; and (3) works well with both airborne and terrestrial laser scanning data. A neighborhood definition based on the shape of the surface increases the homogeneity of the laser point attributes. The magnitude of the normal position vector is used as an attribute for reducing the dimension of the accumulator array. The experimental results demonstrate, through both qualitative and quantitative evaluations, the outcomes' high level of reliability. The proposed segmentation algorithm provided 96.89% overall correctness, 95.84% completeness, a 0.25 m overall mean value of centroid difference, and less than 1° of angle difference. The performance of the proposed approach was also verified with a large dataset and compared with other approaches. Additionally, the evaluation of the sensitivity of the thresholds was carried out. In summary, this paper proposes a robust and efficient segmentation methodology for abstraction of an enormous number of laser points into plane information.

  15. Estimation of regeneration coverage in a temperate forest by 3D segmentation using airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Amiri, Nina; Yao, Wei; Heurich, Marco; Krzystek, Peter; Skidmore, Andrew K.

    2016-10-01

    Forest understory and regeneration are important factors in sustainable forest management. However, understanding their spatial distribution in multilayered forests requires accurate and continuously updated field data, which are difficult and time-consuming to obtain. Therefore, cost-efficient inventory methods are required, and airborne laser scanning (ALS) is a promising tool for obtaining such information. In this study, we examine a clustering-based 3D segmentation in combination with ALS data for regeneration coverage estimation in a multilayered temperate forest. The core of our method is a two-tiered segmentation of the 3D point clouds into segments associated with regeneration trees. First, small parts of trees (super-voxels) are constructed through mean shift clustering, a nonparametric procedure for finding the local maxima of a density function. In the second step, we form a graph based on the mean shift clusters and merge them into larger segments using the normalized cut algorithm. These segments are used to obtain regeneration coverage of the target plot. Results show that, based on validation data from field inventory and terrestrial laser scanning (TLS), our approach correctly estimates up to 70% of regeneration coverage across the plots with different properties, such as tree height and tree species. The proposed method is negatively impacted by the density of the overstory because of decreasing ground point density. In addition, the estimated coverage has a strong relationship with the overstory tree species composition.

  16. Method to quantify accuracy of position feedback signals of a three-dimensional two-photon laser-scanning microscope

    PubMed Central

    Kummer, Michael; Kirmse, Knut; Witte, Otto W.; Haueisen, Jens; Holthoff, Knut

    2015-01-01

    Two-photon laser-scanning microscopy enables to record neuronal network activity in three-dimensional space while maintaining single-cellular resolution. One of the proposed approaches combines galvanometric x-y scanning with piezo-driven objective movements and employs hardware feedback signals for position monitoring. However, readily applicable methods to quantify the accuracy of those feedback signals are currently lacking. Here we provide techniques based on contact-free laser reflection and laser triangulation for the quantification of positioning accuracy of each spatial axis. We found that the lateral feedback signals are sufficiently accurate (defined as <2.5 µm) for a wide range of scan trajectories and frequencies. We further show that axial positioning accuracy does not only depend on objective acceleration and mass but also its geometry. We conclude that the introduced methods allow a reliable quantification of position feedback signals in a cost-efficient, easy-to-install manner and should be applicable for a wide range of two-photon laser scanning microscopes. PMID:26504620

  17. Documenting a Complex Modern Heritage Building Using Multi Image Close Range Photogrammetry and 3d Laser Scanned Point Clouds

    NASA Astrophysics Data System (ADS)

    Vianna Baptista, M. L.

    2013-07-01

    Integrating different technologies and expertises help fill gaps when optimizing documentation of complex buildings. Described below is the process used in the first part of a restoration project, the architectural survey of Theatre Guaira Cultural Centre in Curitiba, Brazil. To diminish time on fieldwork, the two-person-field-survey team had to juggle, during three days, the continuous artistic activities and performers' intense schedule. Both technologies (high definition laser scanning and close-range photogrammetry) were used to record all details in the least amount of time without disturbing the artists' rehearsals and performances. Laser Scanning was ideal to record the monumental stage structure with all of its existing platforms, light fixtures, scenery walls and curtains. Although scanned with high-definition, parts of the exterior façades were also recorded using Close Range Photogrammetry. Tiny cracks on the marble plaques and mosaic tiles, not visible in the point clouds, were then able to be precisely documented in order to create the exterior façades textures and damages mapping drawings. The combination of technologies and the expertise of service providers, knowing how and what to document, and what to deliver to the client, enabled maximum benefits to the following restoration project.

  18. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    SciTech Connect

    Darvin, M E; Richter, H; Zhu, Y J; Meinke, M C; Knorr, F; Lademann, J; Gonchukov, S A; Koenig, K

    2014-07-31

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted. (laser biophotonics)

  19. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors

    NASA Astrophysics Data System (ADS)

    Yuan, Liang (Leon); Herman, Peter R.

    2016-02-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems.

  20. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors

    PubMed Central

    Yuan, Liang (Leon); Herman, Peter R.

    2016-01-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems. PMID:26922872

  1. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    NASA Astrophysics Data System (ADS)

    Darvin, M. E.; Richter, H.; Zhu, Y. J.; Meinke, M. C.; Knorr, F.; Gonchukov, S. A.; Koenig, K.; Lademann, J.

    2014-07-01

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted.

  2. Quantification of facial movements by optical instruments: surface laser scanning and optoelectronic three-dimensional motion analyzer.

    PubMed

    Sidequersky, Fernanda Vincia; Verzé, Laura; Mapelli, Andrea; Ramieri, Guglielmo Amedeo; Sforza, Chiarella

    2014-01-01

    The objective of this study was to assess the accuracy of displacements of tracing landmarks in standardized facial movements. Forty healthy persons were evaluated in 2 different groups (20 men and 20 women, aged 18-30 years) with optoelectronic motion analyzer and surface laser scanning. The displacements of tracing landmarks in brow lift and smile were calculated, and the 2 methods (optoelectronic motion analyzer and surface laser scanning) were compared in healthy persons. Side-related differences were found in the tracing landmark (superciliare) during brow lift movements between both methods (the largest movements were found on the right side, P = 0.044), whereas in smile movements the tracing landmark cheilion did not show significant differences between the 2 sides. In both movements, the differences of the tracing landmark displacements between the 2 systems and sexes were on average less than 2 mm, without statistically significant differences (P > 0.05). In conclusion, normal young adult men and women had similar standardized facial movements. The 2 analyzed movements can be measured by both optical instruments with comparable results.

  3. Terrestrial and Aerial Laser Scanning Data Integration Using Wavelet Analysis for the Purpose of 3D Building Modeling

    PubMed Central

    Kedzierski, Michal; Fryskowska, Anna

    2014-01-01

    Visualization techniques have been greatly developed in the past few years. Three-dimensional models based on satellite and aerial imagery are now being enhanced by models generated using Aerial Laser Scanning (ALS) data. The most modern of such scanning systems have the ability to acquire over 50 points per square meter and to register a multiple echo, which allows the reconstruction of the terrain together with the terrain cover. However, ALS data accuracy is less than 10 cm and the data is often incomplete: there is no information about ground level (in most scanning systems), and often around the facade or structures which have been covered by other structures. However, Terrestrial Laser Scanning (TLS) not only acquires higher accuracy data (1–5 cm) but is also capable of registering those elements which are incomplete or not visible using ALS methods (facades, complicated structures, interiors, etc.). Therefore, to generate a complete 3D model of a building in high Level of Details, integration of TLS and ALS data is necessary. This paper presents the wavelet-based method of processing and integrating data from ALS and TLS. Methods of choosing tie points to combine point clouds in different datum will be analyzed. PMID:25004157

  4. Segmentation of Planar Surfaces from Laser Scanning Data Using the Magnitude of Normal Position Vector for Adaptive Neighborhoods

    PubMed Central

    Kim, Changjae; Habib, Ayman; Pyeon, Muwook; Kwon, Goo-rak; Jung, Jaehoon; Heo, Joon

    2016-01-01

    Diverse approaches to laser point segmentation have been proposed since the emergence of the laser scanning system. Most of these segmentation techniques, however, suffer from limitations such as sensitivity to the choice of seed points, lack of consideration of the spatial relationships among points, and inefficient performance. In an effort to overcome these drawbacks, this paper proposes a segmentation methodology that: (1) reduces the dimensions of the attribute space; (2) considers the attribute similarity and the proximity of the laser point simultaneously; and (3) works well with both airborne and terrestrial laser scanning data. A neighborhood definition based on the shape of the surface increases the homogeneity of the laser point attributes. The magnitude of the normal position vector is used as an attribute for reducing the dimension of the accumulator array. The experimental results demonstrate, through both qualitative and quantitative evaluations, the outcomes’ high level of reliability. The proposed segmentation algorithm provided 96.89% overall correctness, 95.84% completeness, a 0.25 m overall mean value of centroid difference, and less than 1° of angle difference. The performance of the proposed approach was also verified with a large dataset and compared with other approaches. Additionally, the evaluation of the sensitivity of the thresholds was carried out. In summary, this paper proposes a robust and efficient segmentation methodology for abstraction of an enormous number of laser points into plane information. PMID:26805849

  5. Characterization of atopic skin and the effect of a hyperforin-rich cream by laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Meinke, Martina C.; Richter, Heike; Kleemann, Anke; Lademann, Juergen; Tscherch, Kathrin; Rohn, Sascha; Schempp, Christoph M.

    2015-05-01

    Atopic dermatitis (AD) is a multifactorial inflammatory skin disease that affects both children and adults in an increasing manner. The treatment of AD often reduces subjective skin parameters, such as itching, dryness, and tension, but the inflammation cannot be cured. Laser scanning microscopy was used to investigate the skin surface, epidermal, and dermal characteristics of dry and atopic skin before and after treatment with an ointment rich in hyperforin, which is known for its anti-inflammatory effects. The results were compared to subjective parameters and transepidermal water loss, stratum corneum moisture, and stratum corneum lipids. Using biophysical methods, in particular laser scanning microscopy, it was found that atopic skin has distinct features compared to healthy skin. Treatment with a hyperforin-rich ointment resulted in an improvement of the stratum corneum moisture, skin surface dryness, skin lipids, and the subjective skin parameters, indicating that the barrier is stabilized and improved by the ointment. But in contrast to the improved skin surface, the inflammation in the deeper epidermis/dermis often continues to exist. This could be clearly shown by the reflectance confocal microscopy (RCM) measurements. Therefore, RCM measurements could be used to investigate the progress in treatment of atopic dermatitis.

  6. Method to quantify accuracy of position feedback signals of a three-dimensional two-photon laser-scanning microscope.

    PubMed

    Kummer, Michael; Kirmse, Knut; Witte, Otto W; Haueisen, Jens; Holthoff, Knut

    2015-10-01

    Two-photon laser-scanning microscopy enables to record neuronal network activity in three-dimensional space while maintaining single-cellular resolution. One of the proposed approaches combines galvanometric x-y scanning with piezo-driven objective movements and employs hardware feedback signals for position monitoring. However, readily applicable methods to quantify the accuracy of those feedback signals are currently lacking. Here we provide techniques based on contact-free laser reflection and laser triangulation for the quantification of positioning accuracy of each spatial axis. We found that the lateral feedback signals are sufficiently accurate (defined as <2.5 µm) for a wide range of scan trajectories and frequencies. We further show that axial positioning accuracy does not only depend on objective acceleration and mass but also its geometry. We conclude that the introduced methods allow a reliable quantification of position feedback signals in a cost-efficient, easy-to-install manner and should be applicable for a wide range of two-photon laser scanning microscopes. PMID:26504620

  7. Characterization of atopic skin and the effect of a hyperforin-rich cream by laser scanning microscopy.

    PubMed

    Meinke, Martina C; Richter, Heike; Kleemann, Anke; Lademann, Juergen; Tscherch, Kathrin; Rohn, Sascha; Schempp, Christoph M

    2015-05-01

    Atopic dermatitis (AD) is a multifactorial inflammatory skin disease that affects both children and adults in an increasing manner. The treatment of AD often reduces subjective skin parameters, such as itching, dryness, and tension, but the inflammation cannot be cured. Laser scanning microscopy was used to investigate the skin surface, epidermal, and dermal characteristics of dry and atopic skin before and after treatment with an ointment rich in hyperforin, which is known for its anti-inflammatory effects. The results were compared to subjective parameters and transepidermal water loss, stratum corneum moisture, and stratum corneum lipids. Using biophysical methods, in particular laser scanning microscopy, it was found that atopic skin has distinct features compared to healthy skin. Treatment with a hyperforin-rich ointment resulted in an improvement of the stratum corneum moisture, skin surface dryness, skin lipids, and the subjective skin parameters, indicating that the barrier is stabilized and improved by the ointment. But in contrast to the improved skin surface, the inflammation in the deeper epidermis/dermis often continues to exist. This could be clearly shown by the reflectance confocal microscopy (RCM) measurements. Therefore, RCM measurements could be used to investigate the progress in treatment of atopic dermatitis. PMID:25467783

  8. Density of point clouds in mobile laser scanning. (Polish Title: Gestosc chmury punktow pochodzacej z mobilnego skanowania laserowego)

    NASA Astrophysics Data System (ADS)

    Warchoł, A.

    2015-12-01

    The LiDAR (Light Detection And Ranging) technology is becoming a more and more popular method to collect spatial information. The acquisition of 3D data by means of one or several laser scanners mounted on a mobile platform (car) could quickly provide large volumes of dense data with centimeter-level accuracy. This is, therefore, the ideal solution to obtain information about objects with elongated shapes (corridors), and their surroundings. Point clouds used by specific applications must fulfill certain quality criteria, such as quantitative and qualitative indicators (i.e. precision, accuracy, density, completeness).Usually, the client fixes some parameter values that must be achieved. In terms of the precision, this parameter is well described, whereas in the case of density point clouds the discussion is still open. Due to the specificities of the MLS (Mobile Laser Scanning), the solution from ALS (Airborne Laser Scanning) cannot be directly applied. Hence, the density of the final point clouds, calculated as the number of points divided by "flat" surface area, is inappropriate. We present in this article three different ways of determining and interpreting point cloud density on three different test fields. The first method divides the number of points by the "flat" area, the second by the "three-dimensional" area, and the last one refers to a voxel approach. The most reliable method seems to be the voxel method, which in addition to the local density values also presents their spatial distribution.

  9. Detection of human papillomavirus DNA in genital lesions by enzymatic in situ hybridization with Fast Red and laser scanning confocal microscopy.

    PubMed

    Lizard, G; Chignol, M C; Roignot, P; Souchier, C; Chardonnet, Y; Schmitt, D

    1997-07-01

    Human papillomavirus (HPV) infection with potentially oncogenic types 16 or 18 is common in genital lesions especially in uterine carcinomas. In such lesions, in situ hybridization with non-radioactive probes is a powerful tool for the histopathologist to detect and type HPV DNA either on cell deposits or on tissue sections. The use of an immunohistochemical method involving alkaline phosphatase and Fast Red TR salt/naphthol AS-MX phosphate is proposed for use with conventional bright-field or fluorescence microscopy as well as by laser scanning confocal microscopy. The alkaline phosphatase-Fast Red reaction has the advantage of producing a red precipitate that permits the detection of in situ hybridization signals by bright-field microscopy, and of obtaining a strong red fluorescence characterized by a lack of bleaching when excited by a green light. Therefore, the alkaline phosphatase-Fast Red reaction is well adapted for observations by fluorescence and confocal microscopy, the latter method allowing the detection, in tissue sections of cervical intraepithelial lesions, of small punctate and large diffuse hybridization signals, considered as integrated and episomal states of HPV DNA respectively. The combination of in situ hybridization with the alkaline phosphatase-Fast Red reaction and confocal microscopy is particularly convincing when hybridization signals are of small size and/or of low fluorescence intensity, especially if they are present in various focal planes; in such conditions, infected cells are easily detected by three-dimensional reconstruction. Therefore, this combination is a suitable method for identifying and characterizing HPV DNA in cells and tissue sections.

  10. Mapping tree health using airborne full-waveform laser scans and hyperspectral imagery: a case study for floodplain eucalypt forest

    NASA Astrophysics Data System (ADS)

    Shendryk, I.; Tulbure, M. G.; Broich, M.

    2014-12-01

    Barmah-Millewa Forest (BMF), the largest River Red Gum forest in the world, located in south-eastern Australia is suffering from severe dieback, thus diminishing its ecological and economical value. Previous research showed that dieback is a good predictor of the forest health and stressed the need for BMF health mapping and change monitoring. In this respect, airborne laser scanning and hyperspectral imaging offer extensive spatial and spectral coverage of measurements and represent an ideal tool for forest health mapping at individual tree scale. The aim of this project is to quantify the health of individual, structurally complex floodplain eucalypt trees by integrating airborne hyperspectral imagery, full-waveform laser scans and field measurements. An aerial survey, conducted in May 2014, was designed to provide a representative sample of BMF tree health. The positioning of 17 flight lines aimed to capture the heterogeneity of the forest health and flood frequency. Preliminary analysis of the aerial remote sensing data with regards to chlorophyll concentrations, dieback levels and canopy densities allowed us to target our field campaign (conducted in June 2014). Field measurements included accurate position measurements, LAI, visual assessment, spectral measurement and mensuration of individual trees in 30 m2 plots. For detection of individual tree trunks from airborne laser scans we used a novel approach based on Euclidean distance clustering, taking advantage of the intensity and pulse width difference between woody and leaf tree compartments. The detected trunks were used to seed a minimum cut algorithm for tree crown delineation. In situ measurements confirmed the high structural diversity of the forest and allowed the calibration of the tree detection algorithm. An overall accuracy of the tree detection of 54% and 67% was achieved for trees with circumference over 40 cm and over 100 cm respectively. As a further step, 3D point clusters representing

  11. NAVIS-An UGV indoor positioning system using laser scan matching for large-area real-time applications.

    PubMed

    Tang, Jian; Chen, Yuwei; Jaakkola, Anttoni; Liu, Jinbing; Hyyppä, Juha; Hyyppä, Hannu

    2014-01-01

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  12. NAVIS-An UGV Indoor Positioning System Using Laser Scan Matching for Large-Area Real-Time Applications

    PubMed Central

    Tang, Jian.; Chen, Yuwei.; Jaakkola, Anttoni.; Liu, Jinbing.; Hyyppä, Juha.; Hyyppä, Hannu.

    2014-01-01

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  13. NAVIS-An UGV indoor positioning system using laser scan matching for large-area real-time applications.

    PubMed

    Tang, Jian; Chen, Yuwei; Jaakkola, Anttoni; Liu, Jinbing; Hyyppä, Juha; Hyyppä, Hannu

    2014-07-04

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  14. Attempt of correlative observation of morphological synaptic connectivity by combining confocal laser-scanning microscope and FIB-SEM for immunohistochemical staining technique.

    PubMed

    Sonomura, Takahiro; Furuta, Takahiro; Nakatani, Ikuko; Yamamoto, Yo; Honma, Satoru; Kaneko, Takeshi

    2014-11-01

    Ten years have passed since a serial block-face scanning electron microscopy (SBF-SEM) method was developed [1]. In this innovative method, samples were automatically sectioned with an ultramicrotome placed inside a scanning electron microscope column, and the block surfaces were imaged one after another by SEM to capture back-scattered electrons. The contrast-inverted images obtained by the SBF-SEM were very similar to those acquired using conventional TEM. SFB-SEM has made easy to acquire image stacks of the transmission electron microscopy (TEM) in the mesoscale, which is taken with the confocal laser-scanning microcopy(CF-LSM).Furthermore, serial-section SEM has been combined with the focused ion beam (FIB) milling method [2]. FIB-incorporated SEM (FIB-SEM) has enabled the acquisition of three-dimensional images with a higher z-axis resolution com- pared to ultramicrotome-equipped SEM.We tried immunocytochemistry for FIB-SEM and correlated this immunoreactivity with that in CF-LSM. Dendrites of neurons in the rat neostriatum were visualized using a recombinant viral vector. Moreover, the thalamostriatal afferent terminals were immunolabeled with Cy5 fluorescence for vesicular glutamate transporter 2 (VGluT2). After detection of the sites of terminals apposed to the dendrites by using CF-LSM, GFP and VGluT2 immunoreactivities were further developed for EM by using immunogold/silver enhancement and immunoperoxidase/diaminobenzidine (DAB) methods, respectively.We showed that conventional immuno-cytochemical staining for TEM was applicable to FIB-SEM. Furthermore, several synaptic contacts, which were thought to exist on the basis of CF-LSM findings, were confirmed with FIB-SEM, revealing the usefulness of the combined method of CF-LSM and FIB-SEM.

  15. Remote z-scanning with a macroscopic voice coil motor for fast 3D multiphoton laser scanning microscopy

    PubMed Central

    Rupprecht, Peter; Prendergast, Andrew; Wyart, Claire; Friedrich, Rainer W

    2016-01-01

    There is a high demand for 3D multiphoton imaging in neuroscience and other fields but scanning in axial direction presents technical challenges. We developed a focusing technique based on a remote movable mirror that is conjugate to the specimen plane and translated by a voice coil motor. We constructed cost-effective z-scanning modules from off-the-shelf components that can be mounted onto standard multiphoton laser scanning microscopes to extend scan patterns from 2D to 3D. Systems were designed for large objectives and provide high resolution, high speed and a large z-scan range (>300 μm). We used these systems for 3D multiphoton calcium imaging in the adult zebrafish brain and measured odor-evoked activity patterns across >1500 neurons with single-neuron resolution and high signal-to-noise ratio. PMID:27231612

  16. Application of terrestrial laser scanning for detection of ground surface deformation in small mud volcano (Murono, Japan)

    NASA Astrophysics Data System (ADS)

    Hayakawa, Yuichi S.; Kusumoto, Shigekazu; Matta, Nobuhisa

    2016-07-01

    We perform terrestrial laser scanning (TLS) to detect changes in surface morphology of a mud volcano in Murono, north-central Japan. The study site underwent significant deformation by a strong earthquake in 2011, and the surface deformation has continued in the following years. The point cloud datasets were obtained by TLS at three different times in 2011, 2013 and 2014. Those point clouds were aligned by cloud-based registration, which minimizes the closest point distance of point clouds of unchanged ground features, and the TLS-based point cloud data appear to be suitable for detecting centimeter-order deformations in the central domain of the mud volcano, as well as for measurements of topographic features including cracks of paved ground surface. The spatial patterns and accumulative amount of the vertical deformation during 2011-2014 captured by TLS correspond well with those previously reported based on point-based leveling surveys, supporting the validity of TLS survey.

  17. Fractal structure of large-scale variability of wind-driven waves according to laser-scanning data.

    PubMed

    Zosimov, V. V.; Naugol'nykh, K. A.

    1994-03-01

    Results are presented for experimental laser-scanning investigations of the statistical characteristics of wind-driven ocean waves. The method involves counting the number of specular points during scanning of the sea surface by a narrow laser beam on a moving ship. The data analyzed are the set of specular points recorded along a track traced out by the laser beam as a result of the motion of the ship and the scanning beam. A prominent feature is the large-scale variability of the number of specular points and the self-similar nature of the process over a rather wide range of spatial scales. A fractal analysis of the process shows a clear power-law interval in the spatial spectrum of the distribution of specular points.

  18. Investigation of biological cell-protein interactions using SPR sensor through laser scanning confocal imaging-surface plasmon resonance system

    NASA Astrophysics Data System (ADS)

    Zhang, Hongyan; Yang, Liquan; Zhou, Bingjiang; Wang, Xueliang; Liu, Guiying; Liu, Weimin; Wang, Pengfei

    2014-03-01

    A new method for investigating biological cell-protein interactions was developed by using a laser scanning confocal imaging-surface plasmon resonance (LSCI-SPR) system. Mouse normal IgG was modified on the SPR chip. The suspension mouse lymphocyte cancer cells (L5178Y cells) labeled by Hoechst33342 freely flowed into the surface of the SPR sensor chip. By changing the concentration of the cells, the fluorescence images and the SPR signal were synchronously recorded in real time. The red fluorescence points in the imaging region increased with increase in the concentration of the mouse lymphocyte cancer cells and fit well with the change in the SPR signal. Different suspending cells were chosen to investigate cell-protein interactions through antigen-antibody reactions on the biological cell surfaces through binding detection. This method has potential application in cell biology and pharmacology.

  19. Confocal laser scanning microscopic photoconversion: a new method to stabilize fluorescently labeled cellular elements for electron microscopic analysis

    PubMed Central

    Colello, Raymond J.; Tozer, Jordan; Henderson, Scott C.

    2012-01-01

    Photoconversion, the method by which a fluorescent dye is transformed into a stable, osmiophilic product that can be visualized by electron microscopy, is the most widely used method to enable the ultrastructural analysis of fluorescently-labeled cellular structures. Nevertheless, the conventional method of photoconversion using widefield fluorescence microscopy requires long reaction times and results in low resolution cell targeting. Accordingly, we have developed a photoconversion method that ameliorates these limitations by adapting confocal laser scanning microscopy to the procedure. We have found that this method greatly reduces photoconversion times as compared to conventional wide field microscopy. Moreover, region of interest scanning capabilities of a confocal microscope facilitate the targeting of the photoconversion process to individual cellular or subcellular elements within a fluorescent field. This reduces the area of the cell exposed to light energy, thereby reducing the ultrastructural damage common to this process when widefield microscopes are employed. PMID:23042499

  20. The Functional Organization of Neocortical Networks Investigated in Slices with Local Field Recordings and Laser Scanning Photostimulation

    PubMed Central

    Erlandson, Melissa A.; Manzoni, Olivier J.; Bureau, Ingrid

    2015-01-01

    The organization of cortical networks can be investigated functionally in brain slices. Laser scanning photostimulation (LSPS) with glutamate-uncaging allows for a rapid survey of all connections impinging on single cells recorded in patch-clamp. We sought to develop a variant of the method that would allow for a more exhaustive mapping of neuronal networks at every experiment. We found that the extracellular field recordings could be used to detect synaptic responses evoked by LSPS. One to two electrodes were placed in all six cortical layers of barrel cortex successively and maps were computed from the size of synaptic negative local field potentials. The field maps displayed a laminar organization similar to the one observed in maps computed from excitatory postsynaptic currents recorded in patch-clamp mode. Thus, LSPS combined with field recording is an interesting alternative to obtain for every animal tested a comprehensive map of the excitatory intracortical network. PMID:26134668

  1. Analysis of the penetration of a caffeine containing shampoo into the hair follicles by in vivo laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Richter, H.; Schanzer, S.; Klenk, A.; Sterry, W.; Patzelt, A.

    2010-02-01

    In previous in vitro investigations, it was demonstrated that caffeine is able to stimulate the hair growth. Therefore, a penetration of caffeine into the hair follicle is necessary. In the present study, in vivo laser scanning microscopy (LSM) was used to investigate the penetration and storage of a caffeine containing shampoo into the hair follicles. It was shown that a 2-min contact time of the shampoo with the skin was enough to accumulate significant parts of the shampoo in the hair follicles. A penetration of the shampoo up to a depth of approx. 200 μm could be detected, which represents the detection limit of the LSM. At this depth, the close network of the blood capillaries surrounding the hair follicles commences. Even after 24 h, the substance was still detectable in the hair follicles. This demonstrates the long-term reservoir function of the hair follicles for topically applied substances such as caffeine.

  2. Integration of Point Clouds from Terrestrial Laser Scanning and Image-Based Matching for Generating High-Resolution Orthoimages

    NASA Astrophysics Data System (ADS)

    Salach, A.; Markiewicza, J. S.; Zawieska, D.

    2016-06-01

    An orthoimage is one of the basic photogrammetric products used for architectural documentation of historical objects; recently, it has become a standard in such work. Considering the increasing popularity of photogrammetric techniques applied in the cultural heritage domain, this research examines the two most popular measuring technologies: terrestrial laser scanning, and automatic processing of digital photographs. The basic objective of the performed works presented in this paper was to optimize the quality of generated high-resolution orthoimages using integration of data acquired by a Z+F 5006 terrestrial laser scanner and a Canon EOS 5D Mark II digital camera. The subject was one of the walls of the "Blue Chamber" of the Museum of King Jan III's Palace at Wilanów (Warsaw, Poland). The high-resolution images resulting from integration of the point clouds acquired by the different methods were analysed in detail with respect to geometric and radiometric correctness.

  3. High-resolution Crop Surface Models (CSM) and Crop Volume Models (CVM) on field level by terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Hoffmeister, Dirk; Bolten, Andreas; Curdt, Constanze; Waldhoff, Guido; Bareth, Georg

    2010-11-01

    The interdisciplinary Transregional Collaborative Research Center 32 (CRC/TR 32) works on exchange processes between soil, vegetation, and the adjacent atmospheric boundary layer (SVA). Within this research project a terrestrial laser scanning sensor is used in a multitemporal approach for determining agricultural plant parameters. In contrast to other studies with phase-change or optical probe sensors, time-of-flight measurements are used. On three dates in the year 2008 a sugar beet field (4.3 ha) in Western Germany was surveyed by a terrestrial laser scanner (Riegl LMS-Z420i). Point clouds are georeferenced, trimmed, and compared with official elevation data. The estimated plant parameters are (i) surface model comparison between different crop surfaces and (ii) crop volumes as well as (iii) soil roughness parameters for SVA-Modelling. The results show, that the estimation of these parameters is possible and the method should be validated and extended.

  4. Closed-loop control of a 2-D mems micromirror with sidewall electrodes for a laser scanning microscope system

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Chen, Albert; Jie Sun, Wei; Sun, Zhen Dong; Yeow, John TW

    2016-01-01

    This article presents the development and implementation of a robust nonlinear control scheme for a 2-D micromirror-based laser scanning microscope system. The presented control scheme, built around sliding mode control approach and augmented an adaptive algorithm, is proposed to improve the tracking accuracy in presence of cross-axis effect. The closed-loop controlled imaging system is developed through integrating a 2-D micromirror with sidewall electrodes (SW), a laser source, NI field-programmable gate array (FPGA) hardware, the optics, position sensing detector (PSD) and photo detector (PD). The experimental results demonstrated that the proposed scheme is able to achieve accurate tracking of a reference triangular signal. Compared with open-loop control, the scanning performance is significantly improved, and a better 2-D image is obtained using the micromirror with the proposed scheme.

  5. Remote z-scanning with a macroscopic voice coil motor for fast 3D multiphoton laser scanning microscopy.

    PubMed

    Rupprecht, Peter; Prendergast, Andrew; Wyart, Claire; Friedrich, Rainer W

    2016-05-01

    There is a high demand for 3D multiphoton imaging in neuroscience and other fields but scanning in axial direction presents technical challenges. We developed a focusing technique based on a remote movable mirror that is conjugate to the specimen plane and translated by a voice coil motor. We constructed cost-effective z-scanning modules from off-the-shelf components that can be mounted onto standard multiphoton laser scanning microscopes to extend scan patterns from 2D to 3D. Systems were designed for large objectives and provide high resolution, high speed and a large z-scan range (>300 μm). We used these systems for 3D multiphoton calcium imaging in the adult zebrafish brain and measured odor-evoked activity patterns across >1500 neurons with single-neuron resolution and high signal-to-noise ratio. PMID:27231612

  6. High second harmonic generation signal from muscles and fascia pig's muscles using the two-photon laser scanning microscope.

    PubMed

    Reshak, A H

    2009-06-01

    I have provided update to our two photon laser scanning microscope by adding new technique which enables us to simultaneously measured the second harmonic generation signals in the forward and backward directions; in the meantime, one can measure the two photon excitations fluorescence if the materials produce fluorescence. In the present work, the fascia muscles, muscles of pig and pig's skin were used. I found that these materials produced high second harmonic generation signal in both directions. These measurements show that the second harmonic generation strongly depends on the state of the polarization of the laser light and the orientation of the dipole moment in the molecules that interact with the laser light. It is therefore advantageous to control the laser's state of polarization, to maximize second harmonic generation. The novelty of this work is to establish new multi-functional technique by combing three platforms of laser scanning microscopy - the fluorescence microscopy, harmonic generation microscopy and polarizing microscopy in which one can use the second harmonic imaging to investigate the true architecture of the sensitive samples and the samples which do not produce auto-fluorescence. Moreover investigation of the new sample needs to look at all details of the true architecture of the sample. Thereby the sample will be exposed to the laser radiation more than the well-known sample, and that will cause photo-bleaching and photo-damage. Since the second harmonic generation does not undergo from photo-bleaching and photo-damage it will be the promising technique for investigating the sensitive and new samples. Then one can move to acquire fluorescence images after good investigation of the true architecture of the sample by the SH imaging.

  7. 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.

  8. 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

  9. 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

  10. Intravital imaging of the effects of 5-fluorouracil on the murine liver microenvironment using 2-photon laser scanning microscopy

    PubMed Central

    OKIGAMI, MASATO; TANAKA, KOJI; INOUE, YASUHIRO; SAIGUSA, SUSUMU; OKUGAWA, YOSHINAGA; TOIYAMA, YUJI; MOHRI, YASUHIKO; KUSUNOKI, MASATO

    2016-01-01

    5-fluorouracil (5FU) is often used in the treatment of colorectal cancer. 5FU improves the median overall and disease-free survival rates and reduces recurrence rates in patients who have undergone curative surgical resection. However, in the adjuvant setting, whether 5FU eradicates clinically undetectable micrometastases in target organs such as the liver, or whether 5-FU inhibits the adhesion of circulating tumor cells has not yet been established. In the present study, 5FU was administered following the inoculation of red fluorescent protein-expressing HT29 cells into green fluorescent protein (GFP)-transgenic nude mice to examine its inhibitory effect. 2-photon laser scanning microscopy was performed at selected time points for time-series imaging of liver metastasis of GFP-transgenic mice. The cell number in vessels was quantified to evaluate the response of the tumor microenvironment to chemotherapy. HT29 cells were visualized in hepatic sinusoids at the single-cell level. A total of 2 hours after the injection (early stage), time-series imaging revealed that the number of caught tumor cells gradually reduced over time. In the 5FU treatment group, no significant difference was observed in the cell number in the early stage. One week after the injection (late stage), a difference in morphology was observed. The results of the present study indicated that 5FU eradicated clinically undetectable micrometastases in liver tissues by acting as a cytotoxic agent opposed to preventing adhesion. The present study indicated that time-series intravital 2-photon laser scanning microscopic imaging of metastatic tumor xenografts may facilitate the screening and evaluation of novel chemotherapeutic agents with less interindividual variability. PMID:27073493

  11. A new improved protocol for in vitro intratubular dentinal bacterial contamination for antimicrobial endodontic tests: standardization and validation by confocal laser scanning microscopy

    PubMed Central

    de ANDRADE, Flaviana Bombarda; ARIAS, Marcela Paola Castro; MALIZA, Amanda Garcia Alves; DUARTE, Marco Antonio Hungaro; GRAEFF, Márcia Sirlene Zardin; AMOROSO-SILVA, Pablo Andrés; MIDENA, Raquel Zanin; de MORAES, Ivaldo Gomes

    2015-01-01

    Objectives To compare three methods of intratubular contamination that simulate endodontic infections using confocal laser scanning microscopy (CLSM). Material and Methods Two pre-existing models of dentinal contamination were used to induce intratubular infection (groups A and B). These methods were modified in an attempt to improve the model (group C). Among the modifications it may be included: specimen contamination for five days, ultrasonic bath with BHI broth after specimen sterilization, use of E. faecalis during the exponential growth phase, greater concentration of inoculum, and two cycles of centrifugation on alternate days with changes of culture media. All specimens were longitudinally sectioned and stained with of LIVE/DEAD® for 20 min. Specimens were assessed using CLSM, which provided images of the depth of viable bacterial proliferation inside the dentinal tubules. Additionally, three examiners used scores to classify the CLSM images according to the following parameters: homogeneity, density, and depth of the bacterial contamination inside the dentinal tubules. Kruskal-Wallis and Dunn’s tests were used to evaluate the live and dead cells rates, and the scores obtained. Results The contamination scores revealed higher contamination levels in group C when compared with groups A and B (p<0.05). No differences were observed between group A and B (p>0.05). The volume of live cells in group C was higher than in groups A and B (p<0.05). Conclusion The new protocol for intratubular infection resulted in high and uniform patterns of bacterial contamination and higher cell viability in all specimens when compared with the current methods. PMID:26200524

  12. Quantitative microtomography of the early mammalian embryo by laser scanning microscopy.

    PubMed

    Pogorelov, A G; Pogorelova, V N

    2009-10-01

    The blastomer volume was measured by three-dimensional (3D) reconstruction of a series of successive optical sections of the early mouse embryo. Changes in cell volume during osmotic shock were studied. Incubation of a two-cell embryo in Dulbecco's medium induced slow shrinkage of the embryonic cells followed by recovery of its initial volume. A regulatory phase of osmotic shock compensation is characteristic of a blastomer under hypotonic conditions. PMID:20396768

  13. a Comparison of Laser Scanning and Structure from Motion as Applied to the Great Barn at Harmondsworth, UK

    NASA Astrophysics Data System (ADS)

    Andrews, D. P.; Bedford, J.; Bryan, P. G.

    2013-07-01

    The great barn at Harmondsworth near London Heathrow airport, United Kingdom (UK), was built in 1426-7 for the Bishop of Winchester. At 58 metres long and 11.4 metres wide, it is one of the largest ever known to have been built in the UK, and the largest intact medieval timber-framed barn in England. The barn is built almost entirely of oak, although the walls rest on a low masonry sill-wall. Internally the space is divided into a central "nave" with a lower aisle to each side, and is divided along its length into 12 bays. There are three doorways on the east side. For an entirely timber-framed barn, the fabric is exceptionally well preserved. Even the external weatherboarding may be partly original. Following years of neglect, however, there are a number of on-going structural and conservation problems, so in 2011 the barn was bought by English Heritage in order to allow these needs to be addressed. English Heritage is the government agency responsible for the historic sites and buildings in the care of the state of England and is also the UK government's lead advisor on the built heritage. As one of the first steps in the conservation process the English Heritage Geospatial Imaging and Imaging & Visualisation teams undertook a four-day campaign of survey data collection. This took the form of laser scanning of the interior and exterior of the barn plus the acquisition of photography of the exterior elevations to be used with structure from motion (SFM) software. A comparison of the results of these complimentary yet potentially competing technologies will be given, as well as an evaluation of when they can be successfully used together. This paper will describe the procedures and problems involved with collecting the survey data and its subsequent analysis. The laser scanning was undertaken using a FARO Focus 3D phase based instrument. Approximately 60 scans were acquired in order to provide as comprehensive as possible coverage given the site circumstances. A

  14. A segmentation method for 3D visualization of neurons imaged with a confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Anderson, Jeffrey R.; Barrett, Steven F.; Wilcox, Michael J.

    2005-04-01

    Our understanding of the world around us is based primarily on three-dimensional information because of the environment in which we live and interact. Medical or biological image information is often collected in the form of two-dimensional, serial section images. As such, it is difficult for the observer to mentally reconstruct the three dimensional features of each object. Although many image rendering software packages allow for 3D views of the serial sections, they lack the ability to segment, or isolate different objects in the data set. Segmentation is the key to creating 3D renderings of distinct objects from serial slice images, like separate pieces to a puzzle. This paper describes a segmentation method for objects recorded with serial section images. The user defines threshold levels and object labels on a single image of the data set that are subsequently used to automatically segment each object in the remaining images of the same data set, while maintaining boundaries between contacting objects. The performance of the algorithm is verified using mathematically defined shapes. It is then applied to the visual neurons of the housefly, Musca domestica. Knowledge of the fly"s visual system may lead to improved machine visions systems. This effort has provided the impetus to develop this segmentation algorithm. The described segmentation method can be applied to any high contrast serial slice data set that is well aligned and registered. The medical field alone has many applications for rapid generation of 3D segmented models from MRI and other medical imaging modalities.

  15. Polish Experience with Advanced Digital Heritage Recording Methodology, including 3D Laser Scanning, CAD, and GIS Application, as the Most Accurate and Flexible Response for Archaeology and Conservation Needs at Jan III Sobieski's Residence in Wilanów

    NASA Astrophysics Data System (ADS)

    Baranowski, P.; Czajkowski, K.; Gładki, M.; Morysiński, T.; Szambelan, R.; Rzonca, A.

    Review of recent critical points for introduction of laser technology into the field of heritage documentation, management, conservation, and archaeology will be discussed. The relationship of benefit versus cost of 3D laser scanning technique for complex multitask heritage recording project at Wilanow is presented. Definition of basic criteria for the successful use of such heritage detailed record as laser scanning is given.

  16. Comparing terrestrial laser scanning with ground and UAV-based imaging for national-level assessment of upland soil erosion

    NASA Astrophysics Data System (ADS)

    McShane, Gareth; Farrow, Luke; Morgan, David; Glendell, Miriam; James, Mike; Quinton, John; Evans, Martin; Anderson, Karen; Rawlins, Barry; Quine, Timothy; Debell, Leon; Benaud, Pia; Jones, Lee; Kirkham, Matthew; Lark, Murray; Rickson, Jane; Brazier, Richard

    2015-04-01

    Quantifying soil loss through erosion processes at a high resolution can be a time consuming and costly undertaking. In this pilot study 'a cost effective framework for monitoring soil erosion in England and Wales', funded by the UK Department for Environment, Food and Rural Affairs (Defra), we compare methods for collecting suitable topographic measurements via remote sensing. The aim is to enable efficient but detailed site-scale studies of erosion forms in inaccessible UK upland environments, to quantify dynamic processes, such as erosion and mass movement. The techniques assessed are terrestrial laser scanning (TLS), and unmanned aerial vehicle (UAV) photography and ground-based photography, both processed using structure-from-motion (SfM) 3D reconstruction software. Compared to other established techniques, such as expensive TLS, SfM offers a potentially low-cost alternative for the reconstruction of 3D high-resolution micro-topographic models from photographs taken with consumer grade cameras. However, whilst an increasing number of research papers examine the relative merits of these novel versus more established survey techniques, no study to date has compared both ground-based and aerial SfM photogrammetry with TLS scanning across a range of scales (from m2 to 16ha). The evaluation of these novel low cost techniques is particularly relevant in upland landscapes, where the remoteness and inaccessibility of field sites may render some of the more established survey techniques impractical. Volumetric estimates of soil loss are quantified using the digital surface models (DSMs) derived from the data from each technique and subtracted from a modelled pre-erosion surface. The results from each technique are compared. The UAV was able to capture information over a wide area, a range of altitudes and angles over the study area. Combined with automated SfM-based processing, this technique was able to produce rapid orthophotos to support ground-based data

  17. Oral biofilm analysis of palatal expanders by fluorescence in-situ hybridization and confocal laser scanning microscopy.

    PubMed

    Klug, Barbara; Rodler, Claudia; Koller, Martin; Wimmer, Gernot; Kessler, Harald H; Grube, Martin; Santigli, Elisabeth

    2011-10-20

    Confocal laser scanning microscopy (CLSM) of natural heterogeneous biofilm is today facilitated by a comprehensive range of staining techniques, one of them being fluorescence in situ hybridization (FISH). We performed a pilot study in which oral biofilm samples collected from fixed orthodontic appliances (palatal expanders) were stained by FISH, the objective being to assess the three-dimensional organization of natural biofilm and plaque accumulation. FISH creates an opportunity to stain cells in their native biofilm environment by the use of fluorescently labeled 16S rRNA-targeting probes. Compared to alternative techniques like immunofluorescent labeling, this is an inexpensive, precise and straightforward labeling technique to investigate different bacterial groups in mixed biofilm consortia. General probes were used that bind to Eubacteria (EUB338 + EUB338II + EUB338III; hereafter EUBmix), Firmicutes (LGC354 A-C; hereafter LGCmix), and Bacteroidetes (Bac303). In addition, specific probes binding to Streptococcus mutans (MUT590) and Porphyromonas gingivalis (POGI) were used. The extreme hardness of the surface materials involved (stainless steel and acrylic resin) compelled us to find new ways of preparing the biofilm. As these surface materials could not be readily cut with a cryotome, various sampling methods were explored to obtain intact oral biofilm. The most workable of these approaches is presented in this communication. Small flakes of the biofilm-carrying acrylic resin were scraped off with a sterile scalpel, taking care not to damage the biofilm structure. Forceps were used to collect biofilm from the steel surfaces. Once collected, the samples were fixed and placed directly on polysine coated glass slides. FISH was performed directly on these slides with the probes mentioned above. Various FISH protocols were combined and modified to create a new protocol that was easy to handle. Subsequently the samples were analyzed by confocal laser scanning

  18. Oral biofilm analysis of palatal expanders by fluorescence in-situ hybridization and confocal laser scanning microscopy.

    PubMed

    Klug, Barbara; Rodler, Claudia; Koller, Martin; Wimmer, Gernot; Kessler, Harald H; Grube, Martin; Santigli, Elisabeth

    2011-01-01

    Confocal laser scanning microscopy (CLSM) of natural heterogeneous biofilm is today facilitated by a comprehensive range of staining techniques, one of them being fluorescence in situ hybridization (FISH). We performed a pilot study in which oral biofilm samples collected from fixed orthodontic appliances (palatal expanders) were stained by FISH, the objective being to assess the three-dimensional organization of natural biofilm and plaque accumulation. FISH creates an opportunity to stain cells in their native biofilm environment by the use of fluorescently labeled 16S rRNA-targeting probes. Compared to alternative techniques like immunofluorescent labeling, this is an inexpensive, precise and straightforward labeling technique to investigate different bacterial groups in mixed biofilm consortia. General probes were used that bind to Eubacteria (EUB338 + EUB338II + EUB338III; hereafter EUBmix), Firmicutes (LGC354 A-C; hereafter LGCmix), and Bacteroidetes (Bac303). In addition, specific probes binding to Streptococcus mutans (MUT590) and Porphyromonas gingivalis (POGI) were used. The extreme hardness of the surface materials involved (stainless steel and acrylic resin) compelled us to find new ways of preparing the biofilm. As these surface materials could not be readily cut with a cryotome, various sampling methods were explored to obtain intact oral biofilm. The most workable of these approaches is presented in this communication. Small flakes of the biofilm-carrying acrylic resin were scraped off with a sterile scalpel, taking care not to damage the biofilm structure. Forceps were used to collect biofilm from the steel surfaces. Once collected, the samples were fixed and placed directly on polysine coated glass slides. FISH was performed directly on these slides with the probes mentioned above. Various FISH protocols were combined and modified to create a new protocol that was easy to handle. Subsequently the samples were analyzed by confocal laser scanning

  19. Obtaining Seasonal Snow Surface Roughness from Sub-Millimeter to Kilometer Scale Using Plate Photography and Mobile Laser Scanning

    NASA Astrophysics Data System (ADS)

    Anttila, K.; Manninen, T.; Kukko, A.; Kaartinen, H.; Hakala, T.; Kaasalainen, S. M.; Karjalainen, T.; Lahtinen, P.; Krooks, A.; Siljamo, N.; Riihelä, A.

    2013-12-01

    Seasonal snow surface roughness affects the brightness of snow surface and through that the albedo of Earth. It also affects the satellite and radar data of snow surfaces and the wind near the surface. The roughness depends on the direction and distance measured. We have developed a plate-photography method for measuring microscale surface roughness at a resolution of 0.01 mm. The concept is similar to the plate photography method described in Manninen et al. 2012 that can be used to study scales from millimeter to 1-meter scale. Preliminary test measurements were made in different directions daily during one week at the beginning of April 2013. The results have been analysed using multiscale parameters derived from root mean square height (Manninen et al. 1997 &2003). The method proved to be a working concept. For scales longer than one meter we have developed a mobile laser scanning based method for obtaining snow surface roughness (Kukko et al. 2013). In this method we have mounted FGI ROAMER (Kukko et al. 2007) on a sledge driven by a snow mobile. Together these methods will provide means to measure snow surface roughness from sub-millimeter to kilometer scales. Kukko, A., K. Anttila, T. Manninen, H. Kaartinen and S. Kaasalainen (subm.), Snow surface roughness from mobile laser scanning data. Kukko, A., Andrei, C.-O., Salminen, V.-M., Kaartinen, H., Chen, Y., Rönnholm, P., Hyyppä, H., Hyyppä, J., Chen, R., Haggrén, H., Kosonen, I., and Capek K. Road Environment Mapping System of the Finnish Geodetic Institute - FGI Roamer, Int. Arch. Photogramm. Remote Sens., 36, 241-247, 2007. Manninen, A.T. (1997), Surface roughness of Baltic sea ice, Journal of Geophysical Research, Oceans, 102(C1), 1119 -1139. Manninen, A.T. (2003), Multiscale surface roughness description for scattering modeling of bare soil, Physica A, 319, 535 - 551. Manninen, T., K. Anttila, T. Karjalainen, and P. Lahtinen (2012), Automatic snow surface roughness estimation using digital photos

  20. A Bayesian geostatistical estimation of biomass in semi-arid rangelands by combining airborne and terrestrial laser scanning data

    NASA Astrophysics Data System (ADS)

    Li, A.; Glenn, N. F.

    2012-12-01

    Biomass of vegetation is critical for carbon cycle research. Estimating biomass from field survey data is laborious and/or destructive and thus retrieving biomass from remote sensing data may be advantageous. Most remote sensing biomass studies have focused on forest ecosystems, while few have focused on low stature vegetation, such as grasses in semi-arid environments. Biomass estimates for grass are significant for studying wildlife habitat, assessing fuel loads, and studying climate change response in semi-arid regions. Recent research has demonstrated the ability of small footprint airborne laser scanning (ALS) data to extract sagebrush height characteristics and the ability of terrestrial laser scanning (TLS) data to estimate vegetation volume over semi-arid rangelands. ALS has somewhat lower resolution than TLS, but has improved spatial coverage over TLS. Combining ALS and TLS is a powerful tool to estimate biomass on regional scales. Bayesian geostatistics, also known as Bayesian Maximum Entropy (BME), can fuse multiple data sources across scales and provide estimation uncertainties for the integration of ALS and TLS data for grass biomass. Regression models are used to approximately delineate the relationship between field biomass measurements and TLS derived height and shape metrics. We then consider TLS plot-level data at the point scale with ALS data at the area scale. The regularization method is utilized to establish the scaling relations between TLS-derived and ALS-derived metrics. The metric maps from the ALS level are reconstructed using a BME method based on regularized variograms. We gain biomass and estimation uncertainty on the regional scale by introducing updated metrics into the model. In order to evaluate the effectiveness of the BME method, we develop simple independent regression models by assuming the TLS-derived metrics as ground reference data. Therefore, the regression model is used to correct the ALS-estimated values and we retrieve

  1. 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.

  2. The affinity of troxerutin for the venous wall measured by laser scanning microscopy.

    PubMed

    Patwardhan, A; Carlsson, K; Poullain, J C; Taccoen, A; Gerentes, I

    1995-08-01

    The uptake and localization of troxerutin, a trihydroxy-ethyl-rutoside, in the venous wall have been studied in patients undergoing long saphenous vein surgery. Troxerutin, an autofluorescent drug, is currently used to relieve oedema and subjective symptoms in patients with chronic venous insufficiency. In order to determine the localization of the troxerutin, a confocal scanning laser microscope has been used to record the fluorescence from vein cross sections. The quantified fluorescence was used as a measure of the local concentration of troxerutin. In order to reduce the effects of local variation, several images have been scanned from each specimen. Then the recorded data have been analysed to see how the fluorescence varies in the radial direction within the venous wall. Results showed that troxerutin was significantly accumulated in both inner and outer parts of the venous wall. Whereas inner wall troxerutin uptake resulted from direct diffusion through the lumen, the outer wall uptake proceeded likely from the vasa vasorum circulation.

  3. Detection of Cracks in Paved Road Surface Using Laser Scan Image Data

    NASA Astrophysics Data System (ADS)

    Choi, J.; Zhu, L.; Kurosu, H.

    2016-06-01

    In the current study, we developed a methodology for detecting cracks in the surface of paved road using 3D digital surface model of road created by measuring with three-dimensional laser scanner which works on the basis of the light-section method automatically. For the detection of cracks from the imagery data of the model, the background subtraction method (Rolling Ball Background Subtraction Algorithm) was applied to the data for filtering out the background noise originating from the undulation and gradual slope and also for filtering the ruts that were caused by wearing, aging and excessive use of road and other reasons. We confirmed the influence from the difference in height (depth) caused by forgoing reasons included in a data can be reduced significantly at this stage. Various parameters of ball radius were applied for checking how the result of data obtained with this process vary according to the change of parameter and it becomes clear that there are not important differences by the change of parameters if they are in a certain range radius. And then, image segmentation was performed by multi-resolution segmentation based on the object-based image analysis technique. The parameters for the image segmentation, scale, pixel value (height/depth) and the compactness of objects were used. For the classification of cracks in the database, the height, length and other geometric property are used and we confirmed the method is useful for the detection of cracks in a paved road surface.

  4. Automated Confocal Laser Scanning Microscopy and Semiautomated Image Processing for Analysis of Biofilms

    PubMed Central

    Kuehn, Martin; Hausner, Martina; Bungartz, Hans-Joachim; Wagner, Michael; Wilderer, Peter A.; Wuertz, Stefan

    1998-01-01

    The purpose of this study was to develop and apply a quantitative optical method suitable for routine measurements of biofilm structures under in situ conditions. A computer program was designed to perform automated investigations of biofilms by using image acquisition and image analysis techniques. To obtain a representative profile of a growing biofilm, a nondestructive procedure was created to study and quantify undisturbed microbial populations within the physical environment of a glass flow cell. Key components of the computer-controlled processing described in this paper are the on-line collection of confocal two-dimensional (2D) cross-sectional images from a preset 3D domain of interest followed by the off-line analysis of these 2D images. With the quantitative extraction of information contained in each image, a three-dimensional reconstruction of the principal biological events can be achieved. The program is convenient to handle and was generated to determine biovolumes and thus facilitate the examination of dynamic processes within biofilms. In the present study, Pseudomonas fluorescens or a green fluorescent protein-expressing Escherichia coli strain, EC12, was inoculated into glass flow cells and the respective monoculture biofilms were analyzed in three dimensions. In this paper we describe a method for the routine measurements of biofilms by using automated image acquisition and semiautomated image analysis. PMID:9797255

  5. Terrestrial Laser Scanning and Structure from Motion teaching resources for undergraduate field education courses

    NASA Astrophysics Data System (ADS)

    Pratt-Sitaula, B. A.; Shervais, K.; Crosby, C. J.; Douglas, B. J.; Niemi, N. A.; Wang, G.; Charlevoix, D. J.

    2015-12-01

    Fieldwork is an integral part of the geosciences and there is a longstanding tradition of teaching field methods as part of the undergraduate curriculum. As new technology changes the ways in which we scientifically examine the Earth, and as workforce development demands evolve, there is growing interest in introducing these new technologies into field education courses. In collaboration with field education instructors, UNAVCO, the National Science Foundation's geodetic facility, has developed a module of teaching resources to integrate terrestrial lidar scanning into field courses. An NSF facility is well positioned to develop scalable resources that can then be distributed or adapted for broader implementation. The modules can also be accomplished using Structure from Motion methods in place of lidar scanning. Modules goals are for students to be able to: (A) design and conduct a complex TLS survey to address a geologic research question and (B) articulate the societal impetus for answering these research questions and identify why TLS is the appropriate method in some circumstances. The module is comprised of five units: (1) Introduction to survey design, (2) Stratigraphic section analysis, (3) Fault scarp analysis, (4) Geomorphic change detection, (5) Student-led survey design summative assessment. The modules, apart from the Introduction, are independent, thus select modules can be employed in a given field setting. Prototype module materials were developed from the last five years of UNAVCO support of undergraduate field courses. The current versions of the modules were tested in summer 2015 at the Indiana University and University of Michigan field camps. Results show that the majority of students are able to achieve the intended learning goals. Module materials are available on the UNAVCO Education and Community Engagement website.

  6. Detection of macrophage activity in atherosclerosis in vivo using multichannel, high-resolution laser scanning fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Pande, Ashvin N.; Kohler, Rainer; Aikawa, Elena; Weissleder, Ralph; Jaffer, Farouc

    2006-03-01

    Molecular and cellular mechanisms of atherogenesis and its treatment are largely being unraveled by in vitro techniques. We describe methodology to directly image macrophage cell activity in vivo in a murine model of atherosclerosis using laser scanning fluorescence microscopy (LSFM) and a macrophage-targeted, near-infrared fluorescent (NIRF) magnetofluorescent nanoparticle (MFNP). Atherosclerotic apolipoprotein E deficient (apoE -/-) mice (n=10) are injected with MFNP or 0.9% saline, and wild-type mice (n=4) are injected with MFNP as additional controls. After 24 h, common carotid arteries are surgically exposed and prepared for LSFM. Multichannel LSFM of MFNP-enhanced carotid atheroma (5×5-µm in-plane resolution) shows a strong focal NIRF signal, with a plaque target-to-background ratio of 3.9+/-1.8. Minimal NIRF signal is observed in control mice. Spectrally resolved indocyanine green (ICG) fluorescence angiograms confirm the intravascular location of atheroma. On ex vivo fluorescence reflectance imaging, greater NIRF plaque signal is seen in apoE -/- MFNP mice compared to controls (p<0.01). The NIRF signal correlates well with immunostained macrophages, both by stained surface area (r=0.77) and macrophage number (r=0.86). The validated experimental methodology thus establishes a platform for investigating macrophage activity in atherosclerosis in vivo, and has implications for the detection of clinical vulnerable plaques.

  7. The use of airborne laser scanning to develop a pixel-based stratification for a verified carbon offset project

    PubMed Central

    2011-01-01

    Background The voluntary carbon market is a new and growing market that is increasingly important to consider in managing forestland. Monitoring, reporting, and verifying carbon stocks and fluxes at a project level is the single largest direct cost of a forest carbon offset project. There are now many methods for estimating forest stocks with high accuracy that use both Airborne Laser Scanning (ALS) and high-resolution optical remote sensing data. However, many of these methods are not appropriate for use under existing carbon offset standards and most have not been field tested. Results This paper presents a pixel-based forest stratification method that uses both ALS and optical remote sensing data to optimally partition the variability across an ~10,000 ha forest ownership in Mendocino County, CA, USA. This new stratification approach improved the accuracy of the forest inventory, reduced the cost of field-based inventory, and provides a powerful tool for future management planning. This approach also details a method of determining the optimum pixel size to best partition a forest. Conclusions The use of ALS and optical remote sensing data can help reduce the cost of field inventory and can help to locate areas that need the most intensive inventory effort. This pixel-based stratification method may provide a cost-effective approach to reducing inventory costs over larger areas when the remote sensing data acquisition costs can be kept low on a per acre basis. PMID:22004847

  8. Neural Transplant Staining with DiI and Vital Imaging by 2-Photon Laser-Scanning Microscopy

    PubMed Central

    Potter, Steve M.; Pine, Jerome; Fraser, Scott E.

    2008-01-01

    We are developing a multielectrode silicon “neuroprobe” for maintaining a long-term, specific, two-way electrical interface with nervous tissue. Our approach involves trapping a neuron (from an embryonic rat hippocampus) in a small well with a stimulation/recording electrode at its base. The well is covered with a grillwork through which the neuron's processes are allowed to grow, making synaptic contact with the host tissue, in our case a cultured slice from a rat hippocampus. Each neuroprobe can accommodate 15 neurons, one per well. As a first step in studying neurite outgrowth from the neuroprobe, it was necessary to develop new staining techniques so that neurites from the probe neurons can be distinguished from those belonging to the host, without interference from non-specific background staining. We virtually eliminated background staining through a number of innovations involving dye solubility, cell washing, and debris removal. We also reduced photobleaching and phototoxicity, and enhanced imaging depth by using a 2-photon laser-scanning microscope. We focused on using the popular membrane dye, DiI, however a number of other membrane dyes were shown to provide clear images of neural processes using pulsed illumination at 900 nm. These techniques will be useful to others wishing to follow the growth of transplanted neurons over time, in a non-destructive way. PMID:9601539

  9. Real-time in vivo confocal laser scanning microscopy of melanin-containing cells: A promising diagnostic intervention.

    PubMed

    Xiang, Wenzhong; Song, Xiuzu; Peng, Jianzhong; Xu, Aie; Bi, Zhigang

    2015-12-01

    The use of noninvasive imaging techniques to evaluate different types of skin lesions is increasing popular. In vivo confocal laser scanning microscopy (CLSM) is a new method for high resolution non-invasive imaging of intact skin in situ and in vivo. Although many studies have investigated melanin-containing cells in lesions by in vivo CLSM, few studies have systematically characterized melanin-containing cells based on their morphology, size, arrangement, density, borders, and brightness. In this study, the characteristics of melanin-containing cells were further investigated by in vivo CLSM. A total of 130 lesions, including common nevi, giant congenital pigmented nevi, vitiligo, melasma, melanoma, and chronic eczema, were imaged by in vivo CLSM. This research helps dermatologists understand the characteristics of melanin-containing cells and facilitate the clinical application of melanin-containing cells in the investigation of dermatological disease. In summary, melanin-containing cells include keratinocytes, melanocytes, macrophages, and melanocytic skin tumor cells. Our study presents the CLSM characteristics of melanin-containing cells to potentially facilitate in vivo diagnosis based on shape, size, arrangement, density, borders, and brightness.

  10. Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy.

    PubMed

    Nakao, Madoka; Yoshida, Shigeto; Tanaka, Shinji; Takemura, Yoshito; Oka, Shiro; Yoshihara, Masaharu; Chayama, Kazuaki

    2008-01-01

    Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compare prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. 20 sites in the esophagus and 40 sites in the stomach are examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan) is used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei are visualized. In nine of the ten normal esophageal mucosa, cell membranes are visualized, and in five of the ten esophageal cancers, cell membranes are visualized. In all normal gastric mucosa, nuclei and cell membranes are not visualized, but in ten of the 20 gastric cancers, nuclei are visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy.

  11. Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy.

    PubMed

    Nakao, Madoka; Yoshida, Shigeto; Tanaka, Shinji; Takemura, Yoshito; Oka, Shiro; Yoshihara, Masaharu; Chayama, Kazuaki

    2008-01-01

    Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compare prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. 20 sites in the esophagus and 40 sites in the stomach are examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan) is used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei are visualized. In nine of the ten normal esophageal mucosa, cell membranes are visualized, and in five of the ten esophageal cancers, cell membranes are visualized. In all normal gastric mucosa, nuclei and cell membranes are not visualized, but in ten of the 20 gastric cancers, nuclei are visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy. PMID:19021423

  12. Radiation effects on DNA content of cervical cancer cells: A rapid evaluation of radiation sensitivity by laser scanning cytometry

    PubMed Central

    FUJIYOSHI, NAOKI; USHIJIMA, KIMIO; KAWANO, KOUICHIRO; FUJIYOSHI, KEIZO; YAMAGUCHI, TOMOHIKO; ARAKI, YUKO; KAKUMA, TATSUYUKI; WATANABE, SUMIKO; KAKU, TSUNEHISA; NISHIDA, TAKASHI; KAMURA, TOSHIHARU

    2015-01-01

    Since uterine cervical cancer is regarded as a radiosensive tumor, ionizing radiation is the most frequently used treatment modality against the disease. Although the crucial end-point is radiation-induced cell death, the tumors are not equally sensitive to radiation. Determining the criteria that may be used to predict tumor radiosensitivity is of importance; however, little success has been achieved thus far. In radioresistant cases the therapeutic strategy should be changed, thereby avoiding ineffective or unnecessary treatment. Furthermore, identification of the underlying molecular processes leading to radioresistance may lead to novel radiosensitising strategies. Cervical smears were obtained from seven patients with locally advanced cervical cancer following each radiotherapy, and the radiation-induced damage of cancer tissue was examined by routine cytology. Since the formation of DNA double-strand breaks is considered critical for the cytocidal effect of radiation therapy, the molecular changes of the neoplastic cells were also assessed by laser scanning cytometry (LSC). Radiation-induced morphological changes of cancer cells were evident at a dose of 7.2 Gy, whereas increased DNA content (or DNA index) was observed prior to the onset of morphological changes. Molecular change was detected earlier than the morphological change of the irradiated cancer cells, indicating the feasibility of LSC in predicting the radiosensitivity of cervical cancer tissue. PMID:25469269

  13. Precision Automation of Cell Type Classification and Sub-Cellular Fluorescence Quantification from Laser Scanning Confocal Images.

    PubMed

    Hall, Hardy C; Fakhrzadeh, Azadeh; Luengo Hendriks, Cris L; Fischer, Urs

    2016-01-01

    While novel whole-plant phenotyping technologies have been successfully implemented into functional genomics and breeding programs, the potential of automated phenotyping with cellular resolution is largely unexploited. Laser scanning confocal microscopy has the potential to close this gap by providing spatially highly resolved images containing anatomic as well as chemical information on a subcellular basis. However, in the absence of automated methods, the assessment of the spatial patterns and abundance of fluorescent markers with subcellular resolution is still largely qualitative and time-consuming. Recent advances in image acquisition and analysis, coupled with improvements in microprocessor performance, have brought such automated methods within reach, so that information from thousands of cells per image for hundreds of images may be derived in an experimentally convenient time-frame. Here, we present a MATLAB-based analytical pipeline to (1) segment radial plant organs into individual cells, (2) classify cells into cell type categories based upon Random Forest classification, (3) divide each cell into sub-regions, and (4) quantify fluorescence intensity to a subcellular degree of precision for a separate fluorescence channel. In this research advance, we demonstrate the precision of this analytical process for the relatively complex tissues of Arabidopsis hypocotyls at various stages of development. High speed and robustness make our approach suitable for phenotyping of large collections of stem-like material and other tissue types. PMID:26904081

  14. Neuronal nuclei localization in 3D using level set and watershed segmentation from laser scanning microscopy images

    NASA Astrophysics Data System (ADS)

    Zhu, Yingxuan; Olson, Eric; Subramanian, Arun; Feiglin, David; Varshney, Pramod K.; Krol, Andrzej

    2008-03-01

    Abnormalities of the number and location of cells are hallmarks of both developmental and degenerative neurological diseases. However, standard stereological methods are impractical for assigning each cell's nucleus position within a large volume of brain tissue. We propose an automated approach for segmentation and localization of the brain cell nuclei in laser scanning microscopy (LSM) embryonic mouse brain images. The nuclei in these images are first segmented by using the level set (LS) and watershed methods in each optical plane. The segmentation results are further refined by application of information from adjacent optical planes and prior knowledge of nuclear shape. Segmentation is then followed with an algorithm for 3D localization of the centroid of nucleus (CN). Each volume of tissue is thus represented by a collection of centroids leading to an approximate 10,000-fold reduction in the data set size, as compared to the original image series. Our method has been tested on LSM images obtained from an embryonic mouse brain, and compared to the segmentation and CN localization performed by an expert. The average Euclidian distance between locations of CNs obtained using our method and those obtained by an expert is 1.58+/-1.24 µm, a value well within the ~5 µm average radius of each nucleus. We conclude that our approach accurately segments and localizes CNs within cell dense embryonic tissue.

  15. Morphology and deflection properties of bat wing sensory hairs: scanning electron microscopy, laser scanning vibrometry, and mechanics model.

    PubMed

    Sterbing-D'Angelo, S J; Liu, H; Yu, M; Moss, C F

    2016-01-01

    Bat wings are highly adaptive airfoils that enable demanding flight maneuvers, which are performed with astonishing robustness under turbulent conditions, and stability at slow flight velocities. The bat wing is sparsely covered with microscopically small, sensory hairs that are associated with tactile receptors. In a previous study we demonstrated that bat wing hairs are involved in sensing airflow for improved flight maneuverability. Here, we report physical measurements of these hairs and their distribution on the wing surface of the big brown bat, Eptesicus fuscus, based on scanning electron microscopy analyses. The wing hairs are strongly tapered, and are found on both the dorsal and ventral wing surfaces. Laser scanning vibrometry tests of 43 hairs from twelve locations across the wing of the big brown bat revealed that their natural frequencies inversely correlate with length and range from 3.7 to 84.5 kHz. Young's modulus of the average wing hair was calculated at 4.4 GPa, which is comparable with rat whiskers or arthropod airflow-sensing hairs. PMID:27545727

  16. Lab-on-DVD: standard DVD drives as a novel laser scanning microscope for image based point of care diagnostics.

    PubMed

    Ramachandraiah, Harisha; Amasia, Mary; Cole, Jackie; Sheard, Paul; Pickhaver, Simon; Walker, Chris; Wirta, Valtteri; Lexow, Preben; Lione, Richard; Russom, Aman

    2013-04-21

    We present a novel "Lab-on-DVD" system and demonstrate its capability for rapid and low-cost HIV diagnostics by counting CD4+ cells isolated from whole blood. We show that a commercial DVD drive can, with certain modifications, be turned into an improved DVD-based laser scanning microscope (DVD-LSM). The system consists of a multi-layered disposable polymer disc and a modified commercial DVD reader with rotational control for sample handling, temperature control for optimized bioassay, a photodiode array for detection, and software for signal processing and user interface - all the necessary components required for a truly integrated lab-on-a-chip system, with the capability to deliver high-resolution images down to 1 μm in size. Using discs modified with antibodies, we specifically captured CD4+ cells from whole blood, demonstrating single cell resolution imaging. The novel integrated DVD platform with sub-micron image resolution brings, for the first time, affordable cellular diagnostic testing to the point-of-care and should be readily applicable at resource-limited settings.

  17. In vivo high-resolution structural imaging of large arteries in small rodents using two-photon laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Megens, Remco T. A.; Reitsma, Sietze; Prinzen, Lenneke; Oude Egbrink, Mirjam G. A.; Engels, Wim; Leenders, Peter J. A.; Brunenberg, Ellen J. L.; Reesink, Koen D.; Janssen, Ben J. A.; Ter Haar Romeny, Bart M.; Slaaf, Dick W.; van Zandvoort, Marc A. M. J.

    2010-01-01

    In vivo (molecular) imaging of the vessel wall of large arteries at subcellular resolution is crucial for unraveling vascular pathophysiology. We previously showed the applicability of two-photon laser scanning microscopy (TPLSM) in mounted arteries ex vivo. However, in vivo TPLSM has thus far suffered from in-frame and between-frame motion artifacts due to arterial movement with cardiac and respiratory activity. Now, motion artifacts are suppressed by accelerated image acquisition triggered on cardiac and respiratory activity. In vivo TPLSM is performed on rat renal and mouse carotid arteries, both surgically exposed and labeled fluorescently (cell nuclei, elastin, and collagen). The use of short acquisition times consistently limit in-frame motion artifacts. Additionally, triggered imaging reduces between-frame artifacts. Indeed, structures in the vessel wall (cell nuclei, elastic laminae) can be imaged at subcellular resolution. In mechanically damaged carotid arteries, even the subendothelial collagen sheet (~1 μm) is visualized using collagen-targeted quantum dots. We demonstrate stable in vivo imaging of large arteries at subcellular resolution using TPLSM triggered on cardiac and respiratory cycles. This creates great opportunities for studying (diseased) arteries in vivo or immediate validation of in vivo molecular imaging techniques such as magnetic resonance imaging (MRI), ultrasound, and positron emission tomography (PET).

  18. Effect of paeoniflorin on the calcium ion concentration in salivary gland cells using confocal laser scanning microscopy

    PubMed Central

    Qian, Xian; Shi, Xiaolu; Wang, Hongyi

    2016-01-01

    Objective: To investigate the effects of paeoniflorin, the main monomer component of Jinxueyuan granules, on the Ca2+ concentrations in salivary gland cells to further explore the salivation-promoting mechanism and effective monomer components of Jinxueyuan granules. Methods: The salivary gland cells of suckling rats were cultured in vitro and loaded with a Fluo-3AM fluorescent probe, and changes in the intracellular Ca2+ concentrations were observed using a confocal laser scanning microscope. Results: No significant changes in the intracellular Ca2+ concentrations were demonstrated (P>0.05) in the paeoniflorin-free Hank’s media treatment group or in the higher-dose paeoniflorin (10-2 mol/L) Hank’s media treatment group; however, a significant increase in the intracellular Ca2+ concentration in the lower-dose paeoniflorin (10-4 mol/L) treatment group was observed (P=0.001). Further study showed that treatment with the calcium channel blocker verapamil hydrochloride or with Ca2+-free D-Hank’s media did not block the paeoniflorin-induced (10-4 mol/L) increase in intracellular Ca2+ (P<0.05). Conclusion: Paeoniflorin promotes the release of endogenous calcium to upregulate the intracellular Ca2+ concentration. Further studies should be performed to investigate the association between paeoniflorin and the Ca2+ concentration in salivary gland cells and to elucidate the corresponding functional pathways. PMID:27725850

  19. Scan Profiles Based Method for Segmentation and Extraction of Planar Objects in Mobile Laser Scanning Point Clouds

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoang Long; Belton, David; Helmholz, Petra

    2016-06-01

    The demand for accurate spatial data has been increasing rapidly in recent years. Mobile laser scanning (MLS) systems have become a mainstream technology for measuring 3D spatial data. In a MLS point cloud, the point clouds densities of captured point clouds of interest features can vary: they can be sparse and heterogeneous or they can be dense. This is caused by several factors such as the speed of the carrier vehicle and the specifications of the laser scanner(s). The MLS point cloud data needs to be processed to get meaningful information e.g. segmentation can be used to find meaningful features (planes, corners etc.) that can be used as the inputs for many processing steps (e.g. registration, modelling) that are more difficult when just using the point cloud. Planar features are dominating in manmade environments and they are widely used in point clouds registration and calibration processes. There are several approaches for segmentation and extraction of planar objects available, however the proposed methods do not focus on properly segment MLS point clouds automatically considering the different point densities. This research presents the extension of the segmentation method based on planarity of the features. This proposed method was verified using both simulated and real MLS point cloud datasets. The results show that planar objects in MLS point clouds can be properly segmented and extracted by the proposed segmentation method.

  20. Three-dimensional laser scanning and reconstruction of ear canal impressions for optimal design of hearing aid shells

    NASA Astrophysics Data System (ADS)

    Tognola, Gabriella; Parazzini, Marta; Svelto, Cesare; Ravazzani, Paolo; Grandori, Ferdinando

    2003-05-01

    The hearing aid shell (or earmold) couples the hearing aid with the user ear. Proper fitting of the earmold to the subject ear canal is required to achieve satisfactory wearing comfort, reduction in acoustic feedback, and unwanted changes in the electroacoustic characteristics of the aid. To date, the hearing aid shell manufacturing process is fully manual: the shell is fabricated as a replica of the impression of the subject ear canal. The typical post-impression processes made on the ear impression modify the physical dimensions and the shape of the final shell thus affecting the overall performance of the hearing aid. In the proposed approach, the surface of the original ear impression is 3D laser scanned by a prototype equipment consisting of a pair of CCD cameras and a commercial He-Ne laser. The digitized surface is reconstructed by means of iterative deformations of a geometrical model of simple and regular shape. The triangular mesh thus obtained is smoothed by a non-shrinking low-pass spatial filter. With this approach, post-impression processes are no more needed because the digitally reconstructed impression can be directly fed to rapid prototyping equipments, thus achieving a better accuracy in obtaining an exact replica of the ear impression. Furthermore, digital reconstruction of the impression allows for simple and reliable storage and transmission of the model without handling a physical object.

  1. Effects of a topically applied wound ointment on epidermal wound healing studied by in vivo fluorescence laser scanning microscopy analysis

    NASA Astrophysics Data System (ADS)

    Lange-Asschenfeldt, Bernhard; Alborova, Alena; Krüger-Corcoran, Daniela; Patzelt, Alexa; Richter, Heike; Sterry, Wolfram; Kramer, Axel; Stockfleth, Eggert; Lademann, Jürgen

    2009-09-01

    Epidermal wound healing is a complex and dynamic regenerative process necessary to reestablish skin integrity. Fluorescence confocal laser scanning microscopy (FLSM) is a noninvasive imaging technique that has previously been used for evaluation of inflammatory and neoplastic skin disorders in vivo and at high resolution. We employed FLSM to investigate the evolution of epidermal wound healing noninvasively over time and in vivo. Two suction blisters were induced on the volar forearms of the study participants, followed by removal of the epidermis. To study the impact of wound ointment on the process of reepithelization, test sites were divided into two groups, of which one test site was left untreated as a negative control. FLSM was used for serial/consecutive evaluations up to 8 days. FLSM was able to visualize the development of thin keratinocyte layers developing near the wound edge and around hair follicles until the entire epidermis has been reestablished. Wounds treated with the wound ointment were found to heal significantly faster than untreated wounds. This technique allows monitoring of the kinetics of wound healing noninvasively and over time, while offering new insights into the potential effects of topically applied drugs on the process of tissue repair.

  2. Confocal laser scanning and electron microscopical studies on osmoregulatory epithelia in the branchial cavity of the lobster homarus gammarus

    PubMed

    Haond; Flik; Charmantier

    1998-06-01

    The adult lobster Homarus gammarus is a weak hyper-regulator at low salinity. The objective of this study was to locate the ion-transporting tissues in the branchial chamber of this species, using electron microscopy and confocal laser scanning microscopy with a fluorescent vital stain for mitochondria, DASPMI, which is widely used to locate mitochondria-rich cells in ion-transporting epithelia of fish. A thick mitochondria-rich epithelium is present on the inner side of the branchiostegite and over the entire surface of the epipodites. Ultrastructural observations confirm that this tissue has features typical of an ion-transporting epithelium. When the lobster is transferred to low salinity, these epithelia undergo marked ultrastructural changes, such as an increase in thickness related to the development of basolateral infoldings, the appearance of numerous vesicles and an increase in height of the apical microvilli. In the gills, the branchial filaments are lined by a thin and poorly differentiated epithelium, containing numerous mitochondria; no significant ultrastructural changes were observed in the gills of animals acclimated to low salinity. In summary, in H. gammarus, no evidence of osmoregulatory structures was found in the gills. Differentiated ion-transporting epithelia are present in the branchial cavity, on the inner side of the branchiostegite and on the epipodites; these organs are probably involved in osmoregulation. PMID:9576892

  3. Domain observation of potassium-modified NaNbO3 epitaxial films by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Fujii, Ichiro; Wada, Takahiro

    2016-10-01

    Domain structures of (K x Na1- x )NbO3 (x = 0, 0.005, 0.11, 0.18, and 0.30) epitaxial films prepared on SrRuO3/(001) SrTiO3 substrates by pulsed laser deposition were observed by confocal laser scanning microscopy. It was found that the films consisted of stripe domains with in-plane polarization directions at x = 0, mixtures of line and stripe domains with in-plane and out-of-plane polarization directions at x = 0.005 and 0.11, and stripe domains with out-of-plane polarization directions at x = 0.18 and 0.30. After an electric field was applied to the films in the out-of-plane direction, some domains with in-plane polarization directions were changed to domains with out-of-plane polarization directions at x = 0-0.11. It was confirmed that the change in the domain structure of the films with x was consistent with the change in the remanent polarization of their polarization-electric field (P-E) loops.

  4. The lubricative function of artificial joint material surfaces by confocal laser scanning microscopy. Comparison with natural synovial joint surface.

    PubMed

    Kobayashi, Masanori; Oka, Masanori

    2003-01-01

    The purpose of this study was to observe and compare the effect of the behavior of different lubricating surfaces, including articular cartilage and several artificial joint materials, under the physiological loading by confocal laser scanning microscopy (CLSM) to clarify the mechanism of lubrication in natural joints and subsequently improve the quality of artificial joints. In our experiment, even with considerable loading, natural articular cartilage exhibited a synovial fluid area and an area of direct and solid contact. In the region between these two areas, a liquid crystal layer was observed. On the other hand, the materials used for artificial joints (metal and polyethylene, which are now in use, and polyvinyl alcohol-hydrogel polymer which is being developed), did not exhibit neither a clear fluid pool area nor the intermediary area with liquid crystal formation. These results suggest that natural articular cartilage surface has a particular characteristic which builds up a synovial pooling area and liquid crystal formation in the third area by interaction with macromolecules in synovial fluid under the loading condition. These characteristics give natural articular cartilage its excellent lubricative function. To improve the quality of artificial joints, the characteristics of the implant material surface and the synovial macromolecules must be considered. PMID:14646057

  5. Optical effects of the cranium in trans-cranial in vivo two photon laser scanning microscopy in mice

    NASA Astrophysics Data System (ADS)

    Helm, P. Johannes; Ottersen, Ole P.; Nase, Gabriele

    2007-02-01

    The combination of multi photon laser scanning microscopy with transgenic techniques has set the stage for in vivo studies of long term dynamics of the central nervous system in mice. Brain structures located within 100μm to 200μm below the brain surface can be observed minimum-invasively during the post-adolescent life of the animal. However, even when selecting the most appropriate microscope optics available for the purpose, trans-cranial observation is compromised by the aberrations induced by the cranium and the tissue interposed between the cranium and the actual focus. It still is an un-resolved task to calculate these aberrational effects or to, at least, estimate quantitatively the distortions they induce onto the recorded images. Here, we report about measurements of the reflection, the absorption, and the effects on the objective point spread function of the mouse cranium as a function of the thickness of the cranium, the locus of trans-cranial observation and the wavelength. There is experimental evidence for pronounced Second Harmonic Generation (SHG) effects.

  6. Extracting Roof Parameters and Heat Bridges Over the City of Oldenburg from Hyperspectral, Thermal, and Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Bannehr, L.; Luhmann, Th.; Piechel, J.; Roelfs, T.; Schmidt, An.

    2011-09-01

    Remote sensing methods are used to obtain different kinds of information about the state of the environment. Within the cooperative research project HiReSens, funded by the German BMBF, a hyperspectral scanner, an airborne laser scanner, a thermal camera, and a RGB-camera are employed on a small aircraft to determine roof material parameters and heat bridges of house tops over the city Oldenburg, Lower Saxony. HiReSens aims to combine various geometrical highly resolved data in order to achieve relevant evidence about the state of the city buildings. Thermal data are used to obtain the energy distribution of single buildings. The use of hyperspectral data yields information about material consistence of roofs. From airborne laser scanning data (ALS) digital surface models are inferred. They build the basis to locate the best orientations for solar panels of the city buildings. The combination of the different data sets offers the opportunity to capitalize synergies between differently working systems. Central goals are the development of tools for the collection of heat bridges by means of thermal data, spectral collection of roofs parameters on basis of hyperspectral data as well as 3D-capture of buildings from airborne lasers scanner data. Collecting, analyzing and merging of the data are not trivial especially not when the resolution and accuracy is aimed in the domain of a few decimetre. The results achieved need to be regarded as preliminary. Further investigations are still required to prove the accuracy in detail.

  7. Analysis of thin baked-on silicone layers by FTIR and 3D-Laser Scanning Microscopy.

    PubMed

    Funke, Stefanie; Matilainen, Julia; Nalenz, Heiko; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

    2015-10-01

    Pre-filled syringes (PFS) and auto-injection devices with cartridges are increasingly used for parenteral administration. To assure functionality, silicone oil is applied to the inner surface of the glass barrel. Silicone oil migration into the product can be minimized by applying a thin but sufficient layer of silicone oil emulsion followed by thermal bake-on versus spraying-on silicone oil. Silicone layers thicker than 100nm resulting from regular spray-on siliconization can be characterized using interferometric profilometers. However, the analysis of thin silicone layers generated by bake-on siliconization is more challenging. In this paper, we have evaluated Fourier transform infrared (FTIR) spectroscopy after solvent extraction and a new 3D-Laser Scanning Microscopy (3D-LSM) to overcome this challenge. A multi-step solvent extraction and subsequent FTIR spectroscopy enabled to quantify baked-on silicone levels as low as 21-325μg per 5mL cartridge. 3D-LSM was successfully established to visualize and measure baked-on silicone layers as thin as 10nm. 3D-LSM was additionally used to analyze the silicone oil distribution within cartridges at such low levels. Both methods provided new, highly valuable insights to characterize the siliconization after processing, in order to achieve functionality.

  8. Confocal laser scanning microscopy elucidation of the micromorphology of the leaf cuticle and analysis of its chemical composition.

    PubMed

    Nadiminti, Pavani P; Rookes, James E; Boyd, Ben J; Cahill, David M

    2015-11-01

    Electron microscopy techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been invaluable tools for the study of the micromorphology of plant cuticles. However, for electron microscopy, the preparation techniques required may invariably introduce artefacts in cuticle preservation. Further, there are a limited number of methods available for quantifying the image data obtained through electron microscopy. Therefore, in this study, optical microscopy techniques were coupled with staining procedures and, along with SEM were used to qualitatively and quantitatively assess the ultrastructure of plant leaf cuticles. Leaf cryosections of Triticum aestivum (wheat), Zea mays (maize), and Lupinus angustifolius (lupin) were stained with either fat-soluble azo stain Sudan IV or fluorescent, diarylmethane Auramine O and were observed under confocal laser scanning microscope (CLSM). For all the plant species tested, the cuticle on the leaf surfaces could be clearly resolved in many cases into cuticular proper (CP), external cuticular layer (ECL), and internal cuticular layer (ICL). Novel image data analysis procedures for quantifying the epicuticular wax micromorphology were developed, and epicuticular waxes of L. angustifolius were described here for the first time. Together, application of a multifaceted approach involving the use of a range of techniques to study the plant cuticle has led to a better understanding of cuticular structure and provides new insights into leaf surface architecture.

  9. Assessment of cadexomer iodine against Staphylococcus aureus biofilm in vivo and in vitro using confocal laser scanning microscopy.

    PubMed

    Akiyama, Hisanori; Oono, Takashi; Saito, Masakazu; Iwatsuki, Keiji

    2004-07-01

    Cadexomer iodine releases iodine (0.9% weight/weight) slowly from beads of dextrin and epichlorhydrin. This preparation is an effective debridement and antiseptic agent for chronic exdudative wounds. The purpose of the present study is to examine the influence of cadexomer iodine against glycocalyx production of Staphylococcus aureus isolated from furuncle lesions on cut wounds in mice using confocal laser scanning microscope (CLSM), and the increase in and glycocalyx production of S. aureus in vitro. In the present study, distinct S. aureus cells and glycocalyx were not detected in the dermis around the cadexomer iodine beads or within those beads, while S. aureus cells encircled by glycocalyx were soaked up by the cadexomer beads and were detected within them in vivo and in vitro. We suggest that cadexomer iodine soaks up S. aureus cells encircled by glycocalyx, directly destroys biofilm structures, and collapses glycocalyx during dehydration, and further, that iodine can subsequently kill S. aureus cells within biofilm. Cadexomer iodine is a promising treatment to clear S. aureus cells within biofilm from skin lesions of exudative or infectious wounds and to prevent wound exacerbation.

  10. Non destructive analysis of the wax layer of apple (Malus domestica Borkh.) by means of confocal laser scanning microscopy.

    PubMed

    Veraverbeke, E A; Van Bruaene, N; Van Oostveldt, P; Nicolaï, B M

    2001-08-01

    Confocal laser scanning microscopy (CLSM) was used to non-destructively analyse the changes in the structure and thickness of the cuticle during storage of apples (Malus domestica Borkh.). Interpretation of the confocal images was performed by comparison with scanning electron microscopy and environmental scanning electron microscopy images. The natural reflectance of the wax and the auto-fluorescence of the underlying cells made it possible with CLSM to distinguish the wax from the underlying layers without any pretreatment of the fruit. The thickness of the consecutive layers (wax, cutin, cells) could be estimated from measurements of the reflection and fluorescence intensities as a function of the number of pixels. The mean wax-layer thickness measured in this way amounted to 2.58 microm, 3.41 microm or 4.14 microm for the cultivars Jonagold, Jonagored and Elstar, respectively. Changes in the wax structure and cells of the same important Belgian apple cultivars as mentioned above were monitored during nine months of storage in ultra low oxygen and after exposure to ambient conditions. The changes in the wax ultrastructure and cell morphology are likely related to water losses and specific protection of the apple cultivars against water losses during storage and shelf life.

  11. The Inventory Of High Objects Applying Laser Scanning, Focus On The Cataloguing A Reinforced Concrete Industrial Chimney

    NASA Astrophysics Data System (ADS)

    Gawałkiewicz, Rafał

    2015-12-01

    There are many surveying methods to measure the inclination of a chimney with the use of classical protractor instruments (Theo 010A/B, T2 Wild), electronic theodolites (TC2002 Wild-Leica), electronic total stations, including mirrorless ones, allowing to define indirectly the course of the construction's axis on the selected observation levels. The methods are the following: indentations, direct projection, double-edged method, polar method with the option of mirrorless measurement. At the moment a very practical and quick measurement technology, significantly eliminating the influence of human errors on the observation results, is laser scanning. The article presents the results of the scanning of 120-metres high reinforced concrete industrial chimney of the Cement Plant "Ożarów", with the application of modern scanning total station VX Spatial Station by Trimble, as an alternative to the methods applied so far. The advantage of scanning is the possibility to obtain a point cloud, which, apart from the information on the course of the chimney axis in the space, provides detail information on the real shape and deformations of the coating of the object's core.

  12. An Energy-Based Approach for Detection and Characterization of Subtle Entities Within Laser Scanning Point-Clouds

    NASA Astrophysics Data System (ADS)

    Arav, Reuma; Filin, Sagi

    2016-06-01

    Airborne laser scans present an optimal tool to describe geomorphological features in natural environments. However, a challenge arises in the detection of such phenomena, as they are embedded in the topography, tend to blend into their surroundings and leave only a subtle signature within the data. Most object-recognition studies address mainly urban environments and follow a general pipeline where the data are partitioned into segments with uniform properties. These approaches are restricted to man-made domain and are capable to handle limited features that answer a well-defined geometric form. As natural environments present a more complex set of features, the common interpretation of the data is still manual at large. In this paper, we propose a data-aware detection scheme, unbound to specific domains or shapes. We define the recognition question as an energy optimization problem, solved by variational means. Our approach, based on the level-set method, characterizes geometrically local surfaces within the data, and uses these characteristics as potential field for minimization. The main advantage here is that it allows topological changes of the evolving curves, such as merging and breaking. We demonstrate the proposed methodology on the detection of collapse sinkholes.

  13. Laser scanning confocal microscopy coupled with hydraulic permeability measurements for elucidating fluid flow across porous materials: application to human dentine.

    PubMed

    Williams, Cara G; Macpherson, Julie V; Unwin, Patrick R; Parkinson, Charles

    2008-04-01

    Laser scanning confocal microscopy (LSCM) coupled to a constant volume flow-pressure measuring system is introduced as a new technique for the quantitative measurement of fluid flow across porous materials. Such processes are ubiquitous from the life sciences to materials science and the methodology herein could find widespread application. The methodology has been applied to the detection of fluid flow through human dentine, in-vitro, and in the assessment of occlusion actives. Dentine is a calcareous material sandwiched between the pulp and enamel in the tooth structure that contains tubules which traverse dentine in the pulp to enamel direction. The tubules become patent during enamel erosion or gum recession, leading to dentinal hypersensitivity. Understanding the nature of fluid flow is important, as a pressure gradient exists across dentine in-vivo and this has implications for the development of suitable treatments. The methodology described herein firstly allows a ready assessment of the general efficacy of treatments via hydraulic permeability measurements. Second, LSCM images allow the nature of the flow process and the mode of action of the treatments to be revealed at high spatial resolution. For the particular case of dentine, we demonstrate how the method allows candidate treatments to be compared and assessed. PMID:18403832

  14. Creation of High Resolution Terrain Models of Barringer Meteorite Crater (Meteor Crater) Using Photogrammetry and Terrestrial Laser Scanning Methods

    NASA Technical Reports Server (NTRS)

    Brown, Richard B.; Navard, Andrew R.; Holland, Donald E.; McKellip, Rodney D.; Brannon, David P.

    2010-01-01

    Barringer Meteorite Crater or Meteor Crater, AZ, has been a site of high interest for lunar and Mars analog crater and terrain studies since the early days of the Apollo-Saturn program. It continues to be a site of exceptional interest to lunar, Mars, and other planetary crater and impact analog studies because of its relatively young age (est. 50 thousand years) and well-preserved structure. High resolution (2 meter to 1 decimeter) digital terrain models of Meteor Crater in whole or in part were created at NASA Stennis Space Center to support several lunar surface analog modeling activities using photogrammetric and ground based laser scanning techniques. The dataset created by this activity provides new and highly accurate 3D models of the inside slope of the crater as well as the downslope rock distribution of the western ejecta field. The data are presented to the science community for possible use in furthering studies of Meteor Crater and impact craters in general as well as its current near term lunar exploration use in providing a beneficial test model for lunar surface analog modeling and surface operation studies.

  15. Simple approach to improving the extraction of canopy metrics from airborne laser scanning data for tropical forests

    NASA Astrophysics Data System (ADS)

    Hou, Zhengyang; Xu, Qing; Zhang, Chao; Maltamo, Matti; Tokola, Timo

    2016-01-01

    We aim to improve the predictive mapping of stem volume with airborne laser scanning (ALS) data acquired in Laos by adapting the area-based approach (ABA) to a tropical context. Separating laser returns of bushes from main stories with a cut-off threshold is a step very important to the ABA. The adaptation focused here on applying global and plot-adaptive cut-off thresholds to improve the extraction of canopy metrics. In order to select the optimal global cut-off threshold for removing understory bushes and ground objects, a sensitivity analysis of the modeling efficacy to the global cut-off threshold was conducted in the range from 0 to 5 m at 0.1-m intervals. To account for structural variation between plots, a simple plot-adaptive method was proposed for adjusting the threshold of each specific plot. The results showed that the optimal global cut-off threshold, which implicitly assumed the forest structure being homogeneous for all plots was 3.6 m. A model based on the plot-adaptive cut-off thresholds achieved better accuracy (RMSE 28%) than did the optimal global threshold-based model (RMSE 30%). It is concluded that the ALS-based canopy metrics extracted using the plot-adaptive method describe the structural heterogeneity of tropical forests adequately, whereas the global thresholding method is contingent on the forest structure being simple.

  16. Using object-based analysis to derive surface complexity information for improved filtering of airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Yan, Menglong; Blaschke, Thomas; Tang, Hongzhao; Xiao, Chenchao; Sun, Xian; Zhang, Daobing; Fu, Kun

    2016-03-01

    Airborne laser scanning (ALS) is a technique used to obtain Digital Surface Models (DSM) and Digital Terrain Models (DTM) efficiently, and filtering is the key procedure used to derive DTM from point clouds. Generating seed points is an initial step for most filtering algorithms, whereas existing algorithms usually define a regular window size to generate seed points. This may lead to an inadequate density of seed points, and further introduce error type I, especially in steep terrain and forested areas. In this study, we propose the use of objectbased analysis to derive surface complexity information from ALS datasets, which can then be used to improve seed point generation.We assume that an area is complex if it is composed of many small objects, with no buildings within the area. Using these assumptions, we propose and implement a new segmentation algorithm based on a grid index, which we call the Edge and Slope Restricted Region Growing (ESRGG) algorithm. Surface complexity information is obtained by statistical analysis of the number of objects derived by segmentation in each area. Then, for complex areas, a smaller window size is defined to generate seed points. Experimental results show that the proposed algorithm could greatly improve the filtering results in complex areas, especially in steep terrain and forested areas.

  17. Nano-zymography Using Laser-Scanning Confocal Microscopy Unmasks Proteolytic Activity of Cell-Derived Microparticles

    PubMed Central

    Briens, Aurélien; Gauberti, Maxime; Parcq, Jérôme; Montaner, Joan; Vivien, Denis; Martinez de Lizarrondo, Sara

    2016-01-01

    Cell-derived microparticles (MPs) are nano-sized vesicles released by activated cells in the extracellular milieu. They act as vectors of biological activity by carrying membrane-anchored and cytoplasmic constituents of the parental cells. Although detection and characterization of cell-derived MPs may be of high diagnostic and prognostic values in a number of human diseases, reliable measurement of their size, number and biological activity still remains challenging using currently available methods. In the present study, we developed a protocol to directly image and functionally characterize MPs using high-resolution laser-scanning confocal microscopy. Once trapped on annexin-V coated micro-wells, we developed several assays using fluorescent reporters to measure their size, detect membrane antigens and evaluate proteolytic activity (nano-zymography). In particular, we demonstrated the applicability and specificity of this method to detect antigens and proteolytic activities of tissue-type plasminogen activator (tPA), urokinase and plasmin at the surface of engineered MPs from transfected cell-lines. Furthermore, we were able to identify a subset of tPA-bearing fibrinolytic MPs using plasma samples from a cohort of ischemic stroke patients who received thrombolytic therapy and in an experimental model of thrombin-induced ischemic stroke in mice. Overall, this method is promising for functional characterization of cell-derived MPs. PMID:27022410

  18. Monitoring debris flow induced channel morphodynamics with terrestrial laser scanning, Chalk Cliffs, CO (Invited)

    NASA Astrophysics Data System (ADS)

    Wasklewicz, T. A.; Staley, D. M.

    2010-12-01

    Debris flows are important geomorphic agents in alpine drainages. They have be