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Sample records for acquired high resolution

  1. Small UAV-Acquired, High-resolution, Georeferenced Still Imagery

    SciTech Connect

    Ryan Hruska

    2005-09-01

    Currently, small Unmanned Aerial Vehicles (UAVs) are primarily used for capturing and down-linking real-time video. To date, their role as a low-cost airborne platform for capturing high-resolution, georeferenced still imagery has not been fully utilized. On-going work within the Unmanned Vehicle Systems Program at the Idaho National Laboratory (INL) is attempting to exploit this small UAV-acquired, still imagery potential. Initially, a UAV-based still imagery work flow model was developed that includes initial UAV mission planning, sensor selection, UAV/sensor integration, and imagery collection, processing, and analysis. Components to support each stage of the work flow are also being developed. Critical to use of acquired still imagery is the ability to detect changes between images of the same area over time. To enhance the analysts’ change detection ability, a UAV-specific, GIS-based change detection system called SADI or System for Analyzing Differences in Imagery is under development. This paper will discuss the associated challenges and approaches to collecting still imagery with small UAVs. Additionally, specific components of the developed work flow system will be described and graphically illustrated using varied examples of small UAV-acquired still imagery.

  2. Resolution analysis of high-resolution marine seismic data acquired off Yeosu, Korea

    NASA Astrophysics Data System (ADS)

    Lee, Ho-Young; Kim, Wonsik; Koo, Nam-Hyung; Park, Keun-Pil; Yoo, Dong-Geun; Kang, Dong-Hyo; Kim, Young-Gun; Seo, Gab-Seok; Hwang, Kyu-Duk

    2014-05-01

    High-resolution marine seismic surveys have been conducted for the mineral exploration and engineering purpose survey. To improve the quality of high-resolution seismic data, small-scaled multi-channel seismic techniques are used. In this study, we designed high-resolution marine seismic survey using a small airgun and an 8-channel streamer cable and analyzed the resolution of the seismic data related to acquisition and processing parameters. The field survey was conducted off Yeosu, Korea where the stratified thin sedimentary layers are deposited. We used a 30 in3 airgun and an 8-channel streamer cable with a 5 m group interval. We shoot the airgun with a 5 m shot interval and recorded digital data with a 0.1 ms sample interval and 1 s record length. The offset between the source and the first channel was 20 m. We processed the acquired data with simple procedure such as gain recovery, deconvolution, digital filtering, CMP sorting, NMO correction, static correction and stacking. To understand the effect of the acquisition parameters on the vertical and horizontal resolution, we resampled the acquired data using various sample intervals and CMP intervals and produced seismic sections. The analysis results show that the detailed subsurface structures can be imaged with good resolution and continuity using acquisition parameters with a sample interval shorter than 0.2 ms and a CMP interval shorter than 2.5 m. A high-resolution marine 8-channel airgun seismic survey using appropriate acquisition and processing parameters can be effective in imaging marine subsurface structure with a high resolution. This study is a part of a National Research Laboratory (NRL) project and a part of an Energy Technology Innovation (ETI) Project of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), funded by the Ministry of Trade, Industry and Energy (MOTIE). The authors thank the officers and crew of the R/V Tamhae II for their efforts in the field survey.

  3. Ultra-high resolution color images of the surface of comet 67P acquired by ROLIS

    NASA Astrophysics Data System (ADS)

    Schröder, Stefan; Mottola, Stefano; Arnold, Gabriele; Grothues, Hans-Georg; Hamm, Maximilian; Jaumann, Ralf; Michaelis, Harald; Pelivan, Ivanka; Proffe, Gerrit; Bibring, Jean-Pierre

    2015-04-01

    On Nov 12, 2014, the Rosetta Philae lander descended towards comet 67P/Churyumov-Gerasimenko. The onboard ROLIS camera successfully acquired high resolution images of the surface looking down from its vantage point on the instrument platform. ROLIS is a compact CCD imager with a 1024×1024 pixel sensor and a 57° field of view (Mottola et al., 2007, SSR 128, 241). It is equipped with an infinity lens (IFL), without which the camera focus is 30 cm. At Philae's final landing site, ROLIS removed the IFL and initiated an imaging sequence that shows the surface at the highest resolution ever obtained for a cometary surface (~0.5 mm per pixel). Illumination of the scene was provided by an onboard array of LEDs in four different colors: red, green, blue, and near-IR. ROLIS acquired one image for each color and a single dark exposure. The images show a unique, almost fractal morphology for the surface below the landing site that defies easy interpretation. However, there are similarities with some structures seen by the CIVA camera. Color and albedo variations over the surface are minor, and individual grains cannot be distinguished. The images are out-of-focus, indicating the surface was further away than the nominal 30 cm. The location of the illumination spot and the change of focus over the image are consistent with an inclined surface, indicating that Philae's final resting position is strongly tilted. In fact, it was inclined so much that we see the local horizon, even though ROLIS is downward-looking. Remarkably, the scene beyond the horizon is illuminated by the Sun, and out-of-focus particles can be seen to travel in the sky. The images suggest the environment of the lander is laden with fine dust, but a final assessment requires careful consideration of possible sources of stray light. Just before Philae went to sleep, ROLIS acquired an additional exposure with the IFL and the red LED. The resulting image is fully in focus. Because Philae had rotated and lifted

  4. An evaluation of SEBAL algorithm using high resolution aircraft data acquired during BEAREX07

    NASA Astrophysics Data System (ADS)

    Paul, G.; Gowda, P. H.; Prasad, V. P.; Howell, T. A.; Staggenborg, S.

    2010-12-01

    Surface Energy Balance Algorithm for Land (SEBAL) computes spatially distributed surface energy fluxes and evapotranspiration (ET) rates using a combination of empirical and deterministic equations executed in a strictly hierarchical sequence. Over the past decade SEBAL has been tested over various regions and has found its application in solving water resources and irrigation problems. This research combines high resolution remote sensing data and field measurements of the surface radiation and agro-meteorological variables to review various SEBAL steps for mapping ET in the Texas High Plains (THP). High resolution aircraft images (0.5-1.8 m) acquired during the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment 2007 (BEAREX07) conducted at the USDA-ARS Conservation and Production Research Laboratory in Bushland, Texas, was utilized to evaluate the SEBAL. Accuracy of individual relationships and predicted ET were investigated using observed hourly ET rates from 4 large weighing lysimeters, each located at the center of 4.7 ha field. The uniqueness and the strength of this study come from the fact that it evaluates the SEBAL for irrigated and dryland conditions simultaneously with each lysimeter field planted to irrigated forage sorghum, irrigated forage corn, dryland clumped grain sorghum, and dryland row sorghum. Improved coefficients for the local conditions were developed for the computation of roughness length for momentum transport. The decision involved in selection of dry and wet pixels, which essentially determines the partitioning of the available energy between sensible (H) and latent (LE) heat fluxes has been discussed. The difference in roughness length referred to as the kB-1 parameter was modified in the current study. Performance of the SEBAL was evaluated using mean bias error (MBE) and root mean square error (RMSE). An RMSE of ±37.68 W m-2 and ±0.11 mm h-1 was observed for the net radiation and hourly actual ET, respectively

  5. Clinical Application of High-Resolution Computed Tomographic Imaging Features of Community-Acquired Pneumonia

    PubMed Central

    Nie, Yunqiang; Li, Cuiyun; Zhang, Jingling; Wang, Hui; Han, Ping; Lv, Xin; Xu, Xinyi; Guo, Miao

    2016-01-01

    Background This article discusses the value of high-resolution computed tomography (HRCT) in the diagnosis and treatment of pulmonary infections. Lung infection caused by pathogens is an important cause of death. Traditional methods to treat lung infection involved empirical antibiotic therapy. Thin-slice CT scanning is widely used in the clinical setting, and HRCT scan can very clearly show alveolar and bronchiolar involvement of infection. Material/Methods In total, 178 patients with community-acquired pneumonia (CAP) were enrolled. All the patients underwent CT scan, qualified sputum, and blood samples for culture or immunological biochemical tests. CT imaging features, pathogenic bacteria, and treatment results were used for statistical analysis. Results In 77 patients with lobar consolidation, the rate of detection was 43.26% (77/178), and in 101 patients with lobular pneumonia it was 56.74% (101/178). In 51 patients, pathogenic bacteria were detected (28.65%, 51/178). Sixteen of 33 patients detected with bacteria had cavities (48.5%, 16/33) and 35 of 145 patients detected with bacteria had no cavities (24.1%, 35/145). The difference between the 2 groups was statistically significant (χ2=7.795, P=0.005). According to the pathogenic bacteria, 38 patients were cured (74.51%, 38/51), and according to the CT imaging features 81 patients were cured (71.05%, 81/114). No statistically significant difference was found between them (χ2=0.209, P=0.647). Conclusions Treatment effect of CAP based on HRCT findings is not inferior to treatment effect guided by microbial characterization. PMID:27031210

  6. High-Resolution Multichannel Seismic-Reflection Data Acquired in the Northern Gulf of Mexico, 1998-99

    USGS Publications Warehouse

    Hart, Patrick E.; Cooper, Alan K.; Twichell, David C.; Lee, Myung; Agena, Warren

    2002-01-01

    During June 1998 and April 1999, the U.S. Geological Survey (USGS) conducted two research cruises in the northern Gulf of Mexico to acquire high-resolution seismic reflection data across the upper and middle continental slope as part of an investigation of the seismic character, distribution, and potential effects of naturally-occurring marine gas hydrates and related free gas within the gas hydrate stability zone. Over 1600 km of two-dimensional multichannel seismic reflection profiles were acquired during these two cruises. The specific objectives of this investigation are (a) to produce high-resolution images of the gas hydrate stability zone; (b) to study the distribution and character of potential seafloor failures and their relationship to known and inferred gas hydrate deposits; (c) to look at systematic variations in subsurface structure in gas hydrate and non-hydrate areas; and (d) to estimate, if possible, the amounts of hydrates present within the gas hydrate stability zone. The multichannel profiles provide high-quality images with approximately 5 meters of vertical resolution and up to 2 km of penetration. This report gives an overview of the acquisition and data processing of the multichannel seismic reflection profiles and provides references and links to reports with more detailed information. Geologic interpretations of these seismic profiles regarding gas hydrate occurrence and distribution within the study areas of this investigation are given in Cooper and Hart (2002).

  7. Mars Orbiter Camera Acquires High Resolution Stereoscopic Images of the Viking One Landing Site

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Two MOC images of the vicinity of the Viking Lander 1 (MOC 23503 and 25403), acquired separately on 12 April 1998 at 08:32 PDT and 21 April 1998 at 13:54 PDT (respectively), are combined here in a stereoscopic anaglyph. The more recent, slightly better quality image is in the red channel, while the earlier image is shown in the blue and green channels. Only the overlap portion of the images is included in the composite.

    Image 23503 was taken at a viewing angle of 31.6o from vertical; 25403 was taken at an angle of 22.4o, for a difference of 9.4o. Although this is not as large a difference as is typically used in stereo mapping, it is sufficient to provide some indication of relief, at least in locations of high relief.

    The image shows the raised rims and deep interiors of the larger impact craters in the area (the largest crater is about 650 m/2100 feet across). It shows that the relief on the ridges is very subtle, and that, in general, the Viking landing site is very flat. This result is, of course, expected: the VL-1 site was chosen specifically because it was likely to have low to very low slopes that represented potential hazards to the spacecraft.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  8. Evidence of Frontal Rupturing in the Mentawai Gap, SW Sumatra, Newly Acquired High-Resolution Seismic Reflection and Bathymetry Data

    NASA Astrophysics Data System (ADS)

    Hananto, N.; Singh, S. C.; Tapponnier, P.; Sieh, K.; Carton, H. D.; Leclerc, F.; Carson, S.; Wei, S.; Nugroho, A. B.; Avianto, P.; Gemilang, W. A.; Duperray, R.; Permana, H.

    2015-12-01

    We present here the first results of the Mentawai Gap Tsunami Earthquake Research Assessment (MEGATERA) survey, conducted onboard R/V Falkor of the Schmidt Ocean Institute from 23 May-29 July 2015. The Mentawai Gap, located along the Sunda subduction zone offshore SW Sumatra, has been inferred to have the potential to produce a devastating great earthquake in the near future. Along this segment of the megathrust, only limited/small patches ruptured on 12 September 2007, during a twin earthquake of Mw = 8.5 and 7.9, and on October 25th, 2010, during the Mw=7.8 shallow earthquake that generated a large tsunami with run-up of up to ~8 m on Pagai islands. To better understand the mechanism of tsunamigenesis in general and better assess this hazard in the Mentawai locked zone in particular, we acquired a total of 1725 km high-resolution seismic reflection data across the subduction front along with more than 10000 km2 of multibeam bathymetry data. Along the Mentawai trench, we imaged the 2010 tsunami earthquake rupture zone, the Mentawai locked zone, the region impinged by the Investigator Fracture zone as well as the bending-related normal faults dissecting the incoming plate. We find that the morphology of the frontal accretionary wedge section within both the region ruptured in 2010 and the locked segment consists of multiple folds bounded by double-vergent active faults, which when activated during a megathrust event could generate a large tsunami. We also find evidence of mass wasting along thrust escarpments, which could be erosional features or more likely landslides scars triggered by earthquake shaking. The density and distribution of these geologic features along strike could give clues on the seismic history of the segments. These new data will allow us to elucidate the tsunamigenic potential of the Mentawai locked zone.

  9. Large-Volume Reconstruction of Brain Tissue from High-Resolution Serial Section Images Acquired by SEM-Based Scanning Transmission Electron Microscopy

    PubMed Central

    Kuwajima, Masaaki; Mendenhall, John M.; Harris, Kristen M.

    2013-01-01

    With recent improvements in instrumentation and computational tools, serial section electron microscopy has become increasingly straightforward. A new method for imaging ultrathin serial sections is developed based on a field emission scanning electron microscope fitted with a transmitted electron detector. This method is capable of automatically acquiring high-resolution serial images with a large field size and very little optical and physical distortions. In this chapter, we describe the procedures leading to the generation and analyses of a large-volume stack of high-resolution images (64 μm × 64 μm × 10 μm, or larger, at 2 nm pixel size), including how to obtain large-area serial sections of uniform thickness from well-preserved brain tissue that is rapidly perfusion-fixed with mixed aldehydes, processed with a microwave-enhanced method, and embedded into epoxy resin. PMID:23086880

  10. Large-volume reconstruction of brain tissue from high-resolution serial section images acquired by SEM-based scanning transmission electron microscopy.

    PubMed

    Kuwajima, Masaaki; Mendenhall, John M; Harris, Kristen M

    2013-01-01

    With recent improvements in instrumentation and computational tools, serial section electron microscopy has become increasingly straightforward. A new method for imaging ultrathin serial sections is developed based on a field emission scanning electron microscope fitted with a transmitted electron detector. This method is capable of automatically acquiring high-resolution serial images with a large field size and very little optical and physical distortions. In this chapter, we describe the procedures leading to the generation and analyses of a large-volume stack of high-resolution images (64 μm × 64 μm × 10 μm, or larger, at 2 nm pixel size), including how to obtain large-area serial sections of uniform thickness from well-preserved brain tissue that is rapidly perfusion-fixed with mixed aldehydes, processed with a microwave-enhanced method, and embedded into epoxy resin.

  11. Rapid and high-resolution distinction of community-acquired and nosocomial Staphylococcus aureus isolates with identical pulsed-field gel electrophoresis patterns and spa types.

    PubMed

    Glasner, Corinna; Sabat, Artur J; Dreisbach, Annette; Larsen, Anders R; Friedrich, Alexander W; Skov, Robert L; van Dijl, Jan Maarten

    2013-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) represent a serious threat for public health worldwide. Of particular concern is the emergence of community-acquired MRSA, which is often difficult to distinguish from nosocomial MRSA due to a lack of suitable typing methods for early detection. For example, the USA300 pulsed-field gel electrophoresis (PFGE) pattern includes both the 'classical' community-acquired USA300 clone with spa type t008 and an epidemiologically unrelated nosocomial clone with spa type t024. Likewise, spa typing cannot distinguish the classic USA300 from nosocomial MRSA with the spa type t008. Since the fast and high-resolution distinction of these S. aureus types is important for infection prevention and surveillance, we investigated whether multiple-locus variable number tandem repeat fingerprinting (MLVF) can be applied to overcome these limitations. Indeed, MLVF correctly grouped 91 MRSA isolates belonging to the classic USA300 lineage, nosocomial MRSA isolates with the USA300 PFGE profile and spa type t024, and nosocomial MRSA isolates with spa type t008 into 3 distinct clusters. Importantly, several sub-clusters were also identified, reflecting epidemiological relationships between the respective isolates. We conclude that MLVF has the discriminatory power needed to rapidly distinguish very similar community-acquired and nosocomial MRSA isolates and that MLVF-based sub-clustering of isolates is highly useful for epidemiological investigations, outbreak prevention, and control.

  12. High-resolution chirp seismic reflection data acquired from the Cap de Creus shelf and canyon area, Gulf of Lions, Spain in 2004

    USGS Publications Warehouse

    Grossman, Eric E.; Hart, Patrick E.; Field, Michael E.; Triezenberg, Peter

    2006-01-01

    Seismic reflection data were collected from the Cap de Creus shelf and canyon in the southwest portion of the Gulf of Lions in October 2004. The data were acquired using the U.S. Geological Survey`s (USGS) high-resolution Edgetech CHIRP 512i seismic reflection system aboard the R/V Oceanus. Data from the shipboard 3.5 kHz echosounder were also collected but are not presented here. The seismic reflection data were collected as part of EuroSTRATAFORM funded by the Office of Naval Research. In October 2004, more than 200 km of high resolution seismic reflection data were collected in water depths ranging 30 m - 600 m. All data were recorded with a Delph Seismic PC-based digital recording system and processed with Delph Seismic software. Processed sections were georeferenced into tiff images for digital archive, processing and display. Penetration ranged 20-80 m. The data feature high quality vertical cross-section imagery of numerous sequences of Quaternary seismic stratigraphy. The report includes trackline maps showing the location of the data, as well as both digital data files (SEG-Y) and images of all of the profiles. The data are of high quality and provide new information on the location and thickness of sediment deposits overlying a major erosion surface on the Cap de Creus shelf; they also provide new insight into sediment processes on the walls and in the channel of Cap de Creus Canyon. These data are under study by researchers at the US Geological Survey, the University of Barcelona, and Texas A and M University. Copies of the data are available to all researchers.

  13. Planetary Boundary Layer (PBL) Heights Derived From NASA Langley Airborne High Spectral Resolution Lidar (HSRL) Data Acquired During TexAQS/GoMACCS, CHAPS, and MILAGRO

    NASA Astrophysics Data System (ADS)

    Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.; Cook, A.; Harper, D.; Obland, M. D.; Rogers, R. R.

    2007-12-01

    The NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL) was deployed on the NASA Langley B-200 King Air aircraft in the Mexico City metropolitan area during the Mega-city Initiative: Local and Global Research Observations (MILAGRO) campaign in March 2006; in the Houston metropolitan area during the Texas Air Quality Study (TexAQS)/Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) in August and September 2006; and in the Oklahoma City area during Cumulus Humilis Aerosol Processing Study (CHAPS) in June 2007. The HSRL instrument measures profiles of aerosol extinction, backscatter and depolarization. The height of the Planetary Boundary Layer was derived by identifying sharp gradients in the HSRL 532-nm aerosol backscatter signal profiles using an automated technique based on Brooks (2003) [I.M. Brooks, Finding Boundary Layer Top: Application of Wavelet Covariance Transform to Lidar Backscatter Profiles. Journal of Atmospheric and Oceanic Technology 20, 1092-1105, 2003]. The technique uses a Haar wavelet covariance transform with multiple wavelet dilation values to adapt to non-ideal conditions where there can be gradients in the background signals and the boundary layer can be ill defined. The technique also identifies the top and bottom of the transition (i.e. entrainment) zone. We have further modified the algorithm to find PBL heights using HSRL backscatter data acquired during GoMACCS and MILAGRO, where complex terrain and overlying aerosol layers further complicate identifying the boundary layer. In addition, PBL heights are derived from HSRL backscatter data acquired during the CHAPS campaign, in another urban environment where the terrain is not as complex. We will describe the algorithm modifications we have made and show boundary layer heights and transition zone thicknesses for HSRL measurements over the Oklahoma City, Houston, and Mexico City areas during CHAPS, TexAQS/GoMACCS, and MILAGRO.

  14. Mapping of invasive Acacia species in Brazilian Mussununga ecosystems using high- resolution IR remote sensing data acquired with an autonomous Unmanned Aerial System (UAS)

    NASA Astrophysics Data System (ADS)

    Lehmann, Jan Rudolf Karl; Zvara, Ondrej; Prinz, Torsten

    2015-04-01

    The biological invasion of Australian Acacia species in natural ecosystems outside Australia has often a negative impact on native and endemic plant species and the related biodiversity. In Brazil, the Atlantic rainforest of Bahia and Espirito Santo forms an associated type of ecosystem, the Mussununga. In our days this biologically diverse ecosystem is negatively affected by the invasion of Acacia mangium and Acacia auriculiformis, both introduced to Brazil by the agroforestry to increase the production of pulp and high grade woods. In order to detect the distribution of Acacia species and to monitor the expansion of this invasion the use of high-resolution imagery data acquired with an autonomous Unmanned Aerial System (UAS) proved to be a very promising approach. In this study, two types of datasets - CIR and RGB - were collected since both types provide different information. In case of CIR imagery attention was paid on spectral signatures related to plants, whereas in case of RGB imagery the focus was on surface characteristics. Orthophoto-mosaics and DSM/DTM for both dataset were extracted. RGB/IHS transformations of the imagery's colour space were utilized, as well as NDVIblue index in case of CIR imagery to discriminate plant associations. Next, two test areas were defined in order validate OBIA rule sets using eCognition software. In case of RGB dataset, a rule set based on elevation distinction between high vegetation (including Acacia) and low vegetation (including soils) was developed. High vegetation was classified using Nearest Neighbour algorithm while working with the CIR dataset. The IHS information was used to mask shadows, soils and low vegetation. Further Nearest Neighbour classification was used for distinction between Acacia and other high vegetation types. Finally an accuracy assessment was performed using a confusion matrix. One can state that the IHS information appeared to be helpful in Acacia detection while the surface elevation

  15. Swell effect correction for the high-resolution marine seismic data acquired using an airgun and an 8-channel streamer cable

    NASA Astrophysics Data System (ADS)

    Lee, Ho-Young; Koo, Nam-Hyung; Kim, Wonsik; Kim, Byoung-yeop; Cheong, Snons; Kim, Young-Jun

    2015-04-01

    High-resolution marine seismic surveys are used for the imaging of the detailed subsurface geological structure in engineering and marine geological survey. When the sea state gets worse, the quality of the seismic data become worse due to the sea swell. We corrected the swell effect to enhance the quality of seismic data. To remove the swell effect, we picked the sea bottom location automatically, averaged the picked sea bottom times of the adjacent traces and corrected the differences between the calculated and averaged sea bottom location. To make high quality seismic section, we used high-resolution marine 8-channel airgun seismic data acquired off Yeosu, Korea. The energy source was a 30 in3 airgun and the receiver was a 40 m long 8 channel streamer cable with a group interval of 5 m. The offset distance between the source and the first channel was 20 m. The shot interval was 2 seconds corresponding to ~5 m in distance, assuming ship's speed 5 knots. The data were digitally recorded with a sample interval of 0.1 ms and a record length of 1 s. The processing sequence includes basic processing procedures such as gain recovery, deconvolution, frequency filtering, CMP sorting, NMO correction, swell effect correction and stacking. To select sea bottom location for the swell effect correction, we pick maximum amplitude within the expected range including sea bottom location and find the first location at which the amplitude is larger than the threshold that is 40% of the maximum amplitude. We averaged these two-way travel times of sea bottom and corrected the differences. The range of the swell effect correction was -0.5 ~ 0.4 ms. After correction the continuity of reflectors were improved and high quality of the seismic data was produced. This study is a part of a Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM), a National Research Laboratory (NRL) project supported by the Ministry of Science and Technology (MOST), and

  16. Use of high-resolution imagery acquired from an unmanned aircraft system for fluvial mapping and estimating water-surface velocity in rivers

    NASA Astrophysics Data System (ADS)

    Kinzel, P. J.; Bauer, M.; Feller, M.; Holmquist-Johnson, C.; Preston, T.

    2013-12-01

    The use of unmanned aircraft systems (UAS) for environmental monitoring in the United States is anticipated to increase in the coming years as the Federal Aviation Administration (FAA) further develops guidelines to permit their integration into the National Airspace System. The U.S. Geological Survey's (USGS) National Unmanned Aircraft Systems Project Office routinely obtains Certificates of Authorization from the FAA for utilizing UAS technology for a variety of natural resource applications for the U.S. Department of the Interior (DOI). We evaluated the use of a small UAS along two reaches of the Platte River near Overton Nebraska, USA, to determine the accuracy of the system for mapping the extent and elevation of emergent sandbars and to test the ability of a hovering UAS to identify and track tracers to estimate water-surface velocity. The UAS used in our study is the Honeywell Tarantula Hawk RQ16 (T-Hawk), developed for the U.S. Army as a reconnaissance and surveillance platform. The T-Hawk has been recently modified by USGS, and certified for airworthiness by the DOI - Office of Aviation Services, to accommodate a higher-resolution imaging payload than was originally deployed with the system. The T-Hawk is currently outfitted with a Canon PowerShot SX230 HS with a 12.1 megapixel resolution and intervalometer to record images at a user defined time step. To increase the accuracy of photogrammetric products, orthoimagery and DEMs using structure-from-motion (SFM) software, we utilized ground control points in the study reaches and acquired imagery using flight lines at various altitudes (200-400 feet above ground level) and oriented both parallel and perpendicular to the river. Our results show that the mean error in the elevations derived from SFM in the upstream reach was 17 centimeters and horizontal accuracy was 6 centimeters when compared to 4 randomly distributed targets surveyed on emergent sandbars. In addition to the targets, multiple transects were

  17. A novel super resolution scheme to acquire and process satellite images

    NASA Astrophysics Data System (ADS)

    Yin, Dong-yu; Su, Xiao-feng; Lin, Jian-chun; Wang, Gan-quan; Kuang, Ding-bo

    2013-09-01

    Geosynchronous satellite has obvious limitations for the weight and the scale of payloads, and large aperture optical system is not permitted. The optical diffraction limit of small aperture optical system has an adverse impact on the resolution of the acquired images. Therefore, how to get high resolution images using super-resolution technique with the acquired low resolution images becomes a popular problem investigated by researchers. Here, we present a novel scheme to acquire low resolution images and process them to achieve a high resolution image. Firstly, to acquire low resolution images, we adopt a special arrangement pattern of four CCD staggered arrays on the focal plane in the remote sensing satellite framework .These four CCD linear arrays are parallelized with a 0.25√2 pixel shift along the CCD direction and a 1.25 pixel shift along the scanning direction. The rotation angle between the two directions is 45 degree. The tilting sampling mode and the special arrangement pattern allow the sensor to acquire images with a smaller sampling interval which can give the resolution a greater enhancement. Secondly, to reconstruct a high resolution image of pretty good quality with a magnification factor 4, we propose a novel algorithm based on the iterative-interpolation super resolution algorithm (IISR) and the new edge-directed interpolation algorithm (NEDI). The new algorithm makes a critical improvement to NEDI and introduces it into the multi-frame interpolation in IISR. The algorithm can preserve the edges well and requires a relatively small number of low-resolution images to achieve better reconstruction accuracy .In the last part of the paper, we carry out a simulation experiment, and use MSE as the quality measure. The results demonstrate that our new scheme substantially improves the image resolution with both better quantitative quality and visual quality compared with some previous normal methods.

  18. Summary of results and conclusions based on analysis of volume imaging and high spectral resolution lidar data acquired during FIRE phase 1, part 1

    NASA Technical Reports Server (NTRS)

    Grund, Christian J.; Eloranta, E. W.

    1990-01-01

    The collection of long term global statistics on cloud cover may be most easily accomplished with satellite based observations; however, measurements derived from passive satellite retrieval methods must be calibrated and verified by in situ or ground based remote sensor observations. Verification is not straight forward, however, because the highly variable nature of cloud altitude, morphology, and optical characteristics complicates the scaling of point measurements to satellite footprint sized areas. This is particularly evident for cirrus clouds which may be organized on horizontal scales of 10's of meters to 8 km or more, and have optical depths ranging from less than .003 to greater than 3. Cirrus clouds can strongly influence earths' radiative balance, but, because they are often transmissive, cirrus clouds are difficult to detect and characterize from satellite measurements. Because of its precise ranging capabilities, spatial resolution and sensitivity, lidar observations have played an important role in the detection, depiction, and characterization of cirrus clouds. Some of the characteristics of cirrus clouds are summarized which observed the High Spectral Resolution and Volume Imaging Lidars during the phase 1 IFO and ETO periods.

  19. Summary of results and conclusions based on analysis of volume imaging and high spectral resolution lidar data acquired during FIRE phase 1, part 2

    NASA Technical Reports Server (NTRS)

    Grund, Christian J.; Eloranta, E. W.

    1990-01-01

    Since the fall of 1986, cirrus clouds were observed with backscatter cross sections ranging from less than 1 x 10(exp -7) to 4.2 x 10(exp -5)m/sr, optical thicknesses ranging from less than .003 to greater than 2.7, and bulk average backscatter phase functions from .02 to .065/sr. Cirrus cloud structures were recorded ranging in vertical extent from 0.1 to 8 km, having horizontal scales from 10's of meters to 266 km, and exhibiting aspect ratios of from 1:5 to 1:100. The altitude relationship between cloud top and bottom boundaries and the optical center of the cloud is influenced by the type of formation observed. Cirrus morphology and generation processes appear to be related to the wind field. The high spectral resolution lidar (HSRL) was adapted to the task of cirrus cloud optical property measurement. The HSRL data reported were collected with the CuCl2 transmitter producing 50 mW of output power, achieving eye safe, direct optical depth and backscatter cross section measurements with 10 minute averaging times.

  20. A faster, high resolution, mtPA-GFP-based mitochondrial fusion assay acquiring kinetic data of multiple cells in parallel using confocal microscopy.

    PubMed

    Lovy, Alenka; Molina, Anthony J A; Cerqueira, Fernanda M; Trudeau, Kyle; Shirihai, Orian S

    2012-07-20

    Mitochondrial fusion plays an essential role in mitochondrial calcium homeostasis, bioenergetics, autophagy and quality control. Fusion is quantified in living cells by photo-conversion of matrix targeted photoactivatable GFP (mtPAGFP) in a subset of mitochondria. The rate at which the photoconverted molecules equilibrate across the entire mitochondrial population is used as a measure of fusion activity. Thus far measurements were performed using a single cell time lapse approach, quantifying the equilibration in one cell over an hour. Here, we scale up and automate a previously published live cell method based on using mtPAGFP and a low concentration of TMRE (15 nm). This method involves photoactivating a small portion of the mitochondrial network, collecting highly resolved stacks of confocal sections every 15 min for 1 hour, and quantifying the change in signal intensity. Depending on several factors such as ease of finding PAGFP expressing cells, and the signal of the photoactivated regions, it is possible to collect around 10 cells within the 15 min intervals. This provides a significant improvement in the time efficiency of this assay while maintaining the highly resolved subcellular quantification as well as the kinetic parameters necessary to capture the detail of mitochondrial behavior in its native cytoarchitectural environment. Mitochondrial dynamics play a role in many cellular processes including respiration, calcium regulation, and apoptosis. The structure of the mitochondrial network affects the function of mitochondria, and the way they interact with the rest of the cell. Undergoing constant division and fusion, mitochondrial networks attain various shapes ranging from highly fused networks, to being more fragmented. Interestingly, Alzheimer's disease, Parkinson's disease, Charcot Marie Tooth 2A, and dominant optic atrophy have been correlated with altered mitochondrial morphology, namely fragmented networks. Often times, upon fragmentation

  1. A faster, high resolution, mtPA-GFP-based mitochondrial fusion assay acquiring kinetic data of multiple cells in parallel using confocal microscopy.

    PubMed

    Lovy, Alenka; Molina, Anthony J A; Cerqueira, Fernanda M; Trudeau, Kyle; Shirihai, Orian S

    2012-01-01

    Mitochondrial fusion plays an essential role in mitochondrial calcium homeostasis, bioenergetics, autophagy and quality control. Fusion is quantified in living cells by photo-conversion of matrix targeted photoactivatable GFP (mtPAGFP) in a subset of mitochondria. The rate at which the photoconverted molecules equilibrate across the entire mitochondrial population is used as a measure of fusion activity. Thus far measurements were performed using a single cell time lapse approach, quantifying the equilibration in one cell over an hour. Here, we scale up and automate a previously published live cell method based on using mtPAGFP and a low concentration of TMRE (15 nm). This method involves photoactivating a small portion of the mitochondrial network, collecting highly resolved stacks of confocal sections every 15 min for 1 hour, and quantifying the change in signal intensity. Depending on several factors such as ease of finding PAGFP expressing cells, and the signal of the photoactivated regions, it is possible to collect around 10 cells within the 15 min intervals. This provides a significant improvement in the time efficiency of this assay while maintaining the highly resolved subcellular quantification as well as the kinetic parameters necessary to capture the detail of mitochondrial behavior in its native cytoarchitectural environment. Mitochondrial dynamics play a role in many cellular processes including respiration, calcium regulation, and apoptosis. The structure of the mitochondrial network affects the function of mitochondria, and the way they interact with the rest of the cell. Undergoing constant division and fusion, mitochondrial networks attain various shapes ranging from highly fused networks, to being more fragmented. Interestingly, Alzheimer's disease, Parkinson's disease, Charcot Marie Tooth 2A, and dominant optic atrophy have been correlated with altered mitochondrial morphology, namely fragmented networks. Often times, upon fragmentation

  2. High-Resolution Autoradiography

    NASA Technical Reports Server (NTRS)

    Towe, George C; Gomberg, Henry J; Freemen, J W

    1955-01-01

    This investigation was made to adapt wet-process autoradiography to metallurgical samples to obtain high resolution of segregated radioactive elements in microstructures. Results are confined to development of the technique, which was perfected to a resolution of less than 10 microns. The radioactive samples included carbon-14 carburized iron and steel, nickel-63 electroplated samples, a powder product containing nickel-63, and tungsten-185 in N-155 alloy.

  3. Ultra high resolution tomography

    SciTech Connect

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  4. High-resolution headlamp

    NASA Astrophysics Data System (ADS)

    Gut, Carsten; Cristea, Iulia; Neumann, Cornelius

    2016-04-01

    The following article shall describe how human vision by night can be influenced. At first, front lighting systems that are already available on the market will be described, followed by their analysis with respect to the positive effects on traffic safety. Furthermore, how traffic safety by night can be increased since the introduction of high resolution headlamps shall be discussed.

  5. High resolution drift chambers

    SciTech Connect

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 ..mu..m resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs.

  6. High resolution data acquisition

    DOEpatents

    Thornton, Glenn W.; Fuller, Kenneth R.

    1993-01-01

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  7. High resolution data acquisition

    DOEpatents

    Thornton, G.W.; Fuller, K.R.

    1993-04-06

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock, pulse train, and analog circuitry for generating a triangular wave synchronously with the pulse train (as seen in diagram on patent). The triangular wave has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter counts the clock pulse train during the interval to form a gross event interval time. A computer then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  8. High resolution analysis

    NASA Technical Reports Server (NTRS)

    Robinove, C. J.

    1982-01-01

    The possibilities for the use of high spectral resolution analysis in the field of hydrology and water resources are examined. Critical gaps in scientific knowledge that must be filled before technology can be evaluated involve the spectral response of water, substances dissolved and suspended in water, and substances floating on water. The most complete mapping of oil slicks can be done in the ultraviolet region. A mean of measuring the ultraviolet reflection at the surface from satellite altitudes needs to be determined. The use of high spectral resolution sensors in a reasonable number of narrow bands may be able to sense the reflectance or emission characteristics of water and its contained materials that can be correlated with commonly used water quality variables. Technological alternative available to experiment with problems of sensing water quality are to use existing remote sensing instrumentation in an empirical mode and to develop instruments for either testing hypoteses or conducting empirical experiments.

  9. High Resolution Laboratory Spectroscopy

    NASA Astrophysics Data System (ADS)

    Brünken, S.; Schlemmer, S.

    2016-05-01

    In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA. Among these is the development of broadband techniques for the study of complex organic molecules, like fast scanning conventional absorption spectroscopy based on multiplier chains, chirped pulse instrumentation, or the use of synchrotron facilities. Of similar importance is the extension of the accessible frequency range to THz frequencies, where many light hydrides have their ground state rotational transitions. Another key experimental challenge is the production of sufficiently high number densities of refractory and transient species in the laboratory, where discharges have proven to be efficient sources that can also be coupled to molecular jets. For ionic molecular species sensitive action spectroscopic schemes have recently been developed to overcome some of the limitations of conventional absorption spectroscopy. Throughout this review examples demonstrating the strong interplay between laboratory and observational studies will be given.

  10. High Resolution Doppler Imager

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.

    1999-01-01

    This report summarizes the accomplishments of the High Resolution Doppler Imager (HRDI) on UARS spacecraft during the period 4/l/96 - 3/31/99. During this period, HRDI operation, data processing, and data analysis continued, and there was a high level of vitality in the HRDI project. The HRDI has been collecting data from the stratosphere, mesosphere, and lower thermosphere since instrument activation on October 1, 1991. The HRDI team has stressed three areas since operations commenced: 1) operation of the instrument in a manner which maximizes the quality and versatility of the collected data; 2) algorithm development and validation to produce a high-quality data product; and 3) scientific studies, primarily of the dynamics of the middle atmosphere. There has been no significant degradation in the HRDI instrument since operations began nearly 8 years ago. HRDI operations are fairly routine, although we have continued to look for ways to improve the quality of the scientific product, either by improving existing modes, or by designing new ones. The HRDI instrument has been programmed to collect data for new scientific studies, such as measurements of fluorescence from plants, measuring cloud top heights, and lower atmosphere H2O.

  11. High resolution time interval meter

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

  12. ANL high-resolution injector

    SciTech Connect

    Minehara, E.; Kutschera, W.; Hartog, P.D.; Billquist, P.; Liu, Z.

    1986-05-01

    The ANL (Argonne National Laboratory) high-resolution injector has been installed to obtain higher mass resolution and higher preacceleration, and to utilize effectively the full mass range of ATLAS (Argonne tandem linac accelerator system). Preliminary results of the first beam test are reported briefly. The design and performance, in particular a high-mass-resolution magnet with aberration compensation, are discussed.

  13. High Resolution Formaldehyde Photochemistry

    NASA Astrophysics Data System (ADS)

    Ernest, C. T.; Bauer, D.; Hynes, A. J.

    2010-12-01

    Formaldehyde (HCHO) is the most abundant and most important organic carbonyl compound in the atmosphere. The sources of formaldehyde are the oxidation of methane, isoprene, acetone, and other volatile organic compounds (VOCs); fossil fuel combustion; and biomass burning. The dominant loss mechanism for formaldehyde is photolysis which occurs via two pathways: (R1) HCHO + hv → HCO + H (R2) HCHO + hv → H2 + CO The first pathway (R1) is referred to as the radical channel, while the second pathway (R2) is referred to as the molecular channel. The products of both pathways play a significant role in atmospheric chemistry. The CO that is produced in the molecular channel undergoes further oxidation to produce CO2. Under atmospheric conditions, the H atom and formyl radical that are produced in the radical channel undergo rapid reactions with O2 to produce the hydroperoxyl radical (HO2) via (R3) and (R4). (R3) HCO + O2 → HO2 + CO (R4) H + O2 → HO2 Thus, for every photon absorbed, the photolysis of formaldehyde can contribute one CO2 molecule to the global greenhouse budget or two HO2 radicals to the tropospheric HOx (OH + HO2) cycle. The HO2 radicals produced during formaldehyde photolysis have also been implicated in the formation of photochemical smog. The HO2 radicals act as radical chain carriers and convert NO to NO2, which ultimately results in the catalytic production of O3. Constraining the yield of HO2 produced via HCHO photolysis is essential for improving tropospheric chemistry models. In this study, both the absorption cross section and the quantum yield of the radical channel (R1) were measured at high resolution over the tropospherically relevant wavelength range 304-330 nm. For the cross section measurements a narrow linewidth Nd:YAG pumped dye laser was used with a multi-pass cell. Partial pressures of HCHO were kept below 0.3 torr. Simultaneous measurement of OH LIF in a flame allowed absolute calibration of the wavelength scale. Pressure

  14. High resolution telescope

    DOEpatents

    Massie, Norbert A.; Oster, Yale

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activites. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  15. High Spectral Resolution Lidar Data

    DOE Data Explorer

    Eloranta, Ed

    2004-12-01

    The HSRL provided calibrated vertical profiles of optical depth, backscatter cross section and depoloarization at a wavelength of 532 nm. Profiles were acquired at 2.5 second intervals with 7.5 meter resolution. Profiles extended from an altitude of 100 m to 30 km in clear air. The lidar penetrated to a maximum optical depth of ~ 4 under cloudy conditions. Our data contributed directly to the aims of the M-PACE experiment, providing calibrated optical depth and optical backscatter measurements which were not available from any other instrument.

  16. High resolution signal processing

    NASA Astrophysics Data System (ADS)

    Tufts, Donald W.

    1993-08-01

    Motivated by the goal of efficient, effective, high-speed integrated-circuit realization, we have discovered an algorithm for high speed Fourier analysis called the Arithmetic Fourier Transform (AFT). It is based on the number-theoretic method of Mobius inversion, a method that is well suited for integrated-circuit realization. The computation of the AFT can be carried out in parallel, pipelined channels, and the individual operations are very simple to execute and control. Except for a single scaling in each channel, all the operations are additions or subtractions. Thus, it can reduce the required power, volume, and cost. Also, analog switched-capacitor realizations of the AFT have been studied. We have also analyzed the performance of a broad and useful class of data adaptive signal estimation algorithms. This in turn has led to our proposed improvements in the methods. We have used perturbation analysis of the rank-reduced data matrix to calculate its statistical properties. The improvements made have been demonstrated by computer simulation as well as by comparison with the Cramer-Rao Bound.

  17. Ultra-high resolution computed tomography imaging

    DOEpatents

    Paulus, Michael J.; Sari-Sarraf, Hamed; Tobin, Jr., Kenneth William; Gleason, Shaun S.; Thomas, Jr., Clarence E.

    2002-01-01

    A method for ultra-high resolution computed tomography imaging, comprising the steps of: focusing a high energy particle beam, for example x-rays or gamma-rays, onto a target object; acquiring a 2-dimensional projection data set representative of the target object; generating a corrected projection data set by applying a deconvolution algorithm, having an experimentally determined a transfer function, to the 2-dimensional data set; storing the corrected projection data set; incrementally rotating the target object through an angle of approximately 180.degree., and after each the incremental rotation, repeating the radiating, acquiring, generating and storing steps; and, after the rotating step, applying a cone-beam algorithm, for example a modified tomographic reconstruction algorithm, to the corrected projection data sets to generate a 3-dimensional image. The size of the spot focus of the beam is reduced to not greater than approximately 1 micron, and even to not greater than approximately 0.5 microns.

  18. High Resolution Doppler Lidar

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This Grant supported the development of an incoherent lidar system to measure winds and aerosols in the lower atmosphere. During this period the following activities occurred: (1) an active feedback system was developed to improve the laser frequency stability; (2) a detailed forward model of the instrument was developed to take into account many subtle effects, such as detector non-linearity; (3) a non-linear least squares inversion method was developed to recover the Doppler shift and aerosol backscatter without requiring assumptions about the molecular component of the signal; (4) a study was done of the effects of systematic errors due to multiple etalon misalignment. It was discovered that even for small offsets and high aerosol loadings, the wind determination can be biased by as much as 1 m/s. The forward model and inversion process were modified to account for this effect; and (5) the lidar measurements were validated using rawinsonde balloon measurements. The measurements were found to be in agreement within 1-2 m/s.

  19. Enhanced High Resolution RBS System

    NASA Astrophysics Data System (ADS)

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 Å TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron® accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  20. High resolution digital delay timer

    DOEpatents

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  1. High Resolution Imaging Spectrometer (HIRIS)

    NASA Technical Reports Server (NTRS)

    Conley, Joseph M.; Herring, Mark; Norris, David D.

    1988-01-01

    The High Resolution Imaging Spectrometer (HIRIS), related data system, orbit, and mission operations are described. The pushbroom instrument simultaneously images the terrestrial surface in 192 spectral bands from 0.4 to 2.5 microns. The swath width is 30 km and spatial resolution is 30 m. It is planned to be launched with the Earth Observing System aboard the Space Station Polar Platform in 1995. Array detectors allow concurrent integration of the signals at 192,000 detector elements.

  2. High-resolution imaging ellipsometer.

    PubMed

    Zhan, Qiwen; Leger, James R

    2002-08-01

    We report on a novel imaging ellipsometer using a high-numerical-aperture (NA) objective lens capable of measuring a two-dimensional ellipsometric signal with high resolution. Two-dimensional ellipsometric imaging is made possible by spatial filtering at the pupil plane of the objective. A Richards-Wolf vectorial diffraction model and geometrical optics model are developed to simulate the system. The thickness profile of patterned polymethyl methacrylate is measured for calibration purposes. Our instrument has a sensitivity of 5 A and provides spatial resolution of approximately 0.5 microm with 632.8-nm illumination. Its capability of measuring refractive-index variations with high spatial resolution is also demonstrated.

  3. Mars high-resolution mapping

    NASA Astrophysics Data System (ADS)

    Batson, R. M.; Thomas, P. K.

    1991-06-01

    A series of photomosaics of high-resolution Viking Orbiter images of Mars is being prepared and published to support the Mars 1:500,000 scale geologic mapping program. More than 100 of these photomosaics were made manually, but for the last several years they have all been made digitally. The digital mosaics are published on the Mars Transverse Mercator (MTM) system, and they are also available to the appropriate principal investigators as digital files in the mosaicked digital image model (MDIM) format. The mosaics contain Viking Orbiter images with the highest available resolution: in some areas as high as 10 m/pixel. This resolution, where it exists, will support a 1:100,000 map scale. The full resolution of a mosaic is preserved in a digital file, but conventional lithographic publication of such large-scale inset maps will be done only if required by the geologic map author. When high-resolution images do not fill the neat lines of an MTM quadrangle, the medium-resolution (1/256 degrees/pixel, or 231 m/pixel) MDIM is used. The mosaics are tied by image-matching to the planetwide MDIM, in which random errors as large as 5 km (10 mm at 1:500,000 scale) are common; a few much larger, worst-case errors also occur. Because of the distribution of the errors, many large discrepancies appear along the cutlines between frames with very different resolutions. Furthermore, each block of quadrangles is compiled on its own local control system, and adjacent blocks, compiled later, are unlikely to match. Selection of areas to be mapped is based on geologic mapping proposals reviewed and recommended by the Mars 1:500,000 scale geologic mapping review panel. There is no intention to map the entire planet at this scale.

  4. Evaluation of degree of multifractality for description of high resolution data acquired by Landsat satellites. (Polish Title: Ocena przydatnosci poziomu multifraktalnosci do opisu wysokorozdzielczych danych pozyskanych przez satelity Landsat )

    NASA Astrophysics Data System (ADS)

    Wawrzaszek, A.; Walichnowska, M.; Krupiński, M.

    2015-12-01

    In the frame of this work six satellite images (at six spectral bands) from Landsat 5, Landsat 7 and Landsat 8 have been analysed. For this purpose 30 meter resolution images showing the regions of Warsaw have been used. The conducted research allowed for verification if the whole scene presents multifractal features and if size of the division of the scene used during the analysis has a significant influence on the multifractal characteristic and error in their calculation. Initial interpretation of the obtained results showed, that the use of degree of multifractality determined for remote sensing data with the 30 meters resolution does not reveal direct relation with land cover classes. It should be noted, however, that the considered data have not been the subject of a previous processing, which according to the discussion performed in this work can be considered as one of the methods to achieve an improvement in results.

  5. Advanced very high resolution radiometer

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The advanced very high resolution radiometer development program is considered. The program covered the design, construction, and test of a breadboard model, engineering model, protoflight model, mechanical structural model, and a life test model. Special bench test and calibration equipment was also developed for use on the program.

  6. Requirements on high resolution detectors

    SciTech Connect

    Koch, A.

    1997-02-01

    For a number of microtomography applications X-ray detectors with a spatial resolution of 1 {mu}m are required. This high spatial resolution will influence and degrade other parameters of secondary importance like detective quantum efficiency (DQE), dynamic range, linearity and frame rate. This note summarizes the most important arguments, for and against those detector systems which could be considered. This article discusses the mutual dependencies between the various figures which characterize a detector, and tries to give some ideas on how to proceed in order to improve present technology.

  7. High resolution optical DNA mapping

    NASA Astrophysics Data System (ADS)

    Baday, Murat

    Many types of diseases including cancer and autism are associated with copy-number variations in the genome. Most of these variations could not be identified with existing sequencing and optical DNA mapping methods. We have developed Multi-color Super-resolution technique, with potential for high throughput and low cost, which can allow us to recognize more of these variations. Our technique has made 10--fold improvement in the resolution of optical DNA mapping. Using a 180 kb BAC clone as a model system, we resolved dense patterns from 108 fluorescent labels of two different colors representing two different sequence-motifs. Overall, a detailed DNA map with 100 bp resolution was achieved, which has the potential to reveal detailed information about genetic variance and to facilitate medical diagnosis of genetic disease.

  8. High resolution spectrograph. [for LST

    NASA Technical Reports Server (NTRS)

    Peacock, K.

    1975-01-01

    The high resolution spectrograph (HRS) is designed to be used with the Large Space Telescope (LST) for the study of spectra of point and extended targets in the spectral range 110 to 410 nm. It has spectral resolutions of 1,000; 30,000; and 100,000 and has a field of view as large as 10 arc sec. The spectral range and resolution are selectable using interchangeable optical components and an echelle spectrograph is used to display a cross dispersed spectrum on the photocathode of either of 2 SEC orthicon image tubes. Provisions are included for wavelength calibration, target identification and acquisition and thermal control. The system considerations of the instrument are described.

  9. Variable resolution reconstruction for Cartesian data acquired with nonconstant sampling density in phase-encoding direction.

    PubMed

    Rasche, Volker; Bornstedt, Axel; Hombach, Vinzenz

    2008-03-01

    The variable-kernel extent technique is applied for providing local high-resolution images from k-space data sampled on a Cartesian sampling grid with gradually decreasing sampling density in the phase-encoding direction. The approach is based on a variable spatial resolution reconstruction technique providing gradually decreasing resolution in the phase-encoding direction with increasing distance to the image center, while preserving full spatial resolution in a narrow slab centered in spatial domain. Reconstruction is performed by a variable convolution kernel gridding technique. The convolution kernel width is chosen proportional to the k-space sampling spacing to utilize the respective apodization in the image for reduction of the aliasing artifacts. Application of this technique to carotid artery wall imaging shows the potential of the technique for a significant reduction of image acquisition time without sacrificing image quality in the region of the carotid arteries.

  10. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-08-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  11. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  12. High resolution tomographic instrument development

    NASA Astrophysics Data System (ADS)

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefitted greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  13. HRSC: High resolution stereo camera

    USGS Publications Warehouse

    Neukum, G.; Jaumann, R.; Basilevsky, A.T.; Dumke, A.; Van Gasselt, S.; Giese, B.; Hauber, E.; Head, J. W.; Heipke, C.; Hoekzema, N.; Hoffmann, H.; Greeley, R.; Gwinner, K.; Kirk, R.; Markiewicz, W.; McCord, T.B.; Michael, G.; Muller, Jan-Peter; Murray, J.B.; Oberst, J.; Pinet, P.; Pischel, R.; Roatsch, T.; Scholten, F.; Willner, K.

    2009-01-01

    The High Resolution Stereo Camera (HRSC) on Mars Express has delivered a wealth of image data, amounting to over 2.5 TB from the start of the mapping phase in January 2004 to September 2008. In that time, more than a third of Mars was covered at a resolution of 10-20 m/pixel in stereo and colour. After five years in orbit, HRSC is still in excellent shape, and it could continue to operate for many more years. HRSC has proven its ability to close the gap between the low-resolution Viking image data and the high-resolution Mars Orbiter Camera images, leading to a global picture of the geological evolution of Mars that is now much clearer than ever before. Derived highest-resolution terrain model data have closed major gaps and provided an unprecedented insight into the shape of the surface, which is paramount not only for surface analysis and geological interpretation, but also for combination with and analysis of data from other instruments, as well as in planning for future missions. This chapter presents the scientific output from data analysis and highlevel data processing, complemented by a summary of how the experiment is conducted by the HRSC team members working in geoscience, atmospheric science, photogrammetry and spectrophotometry. Many of these contributions have been or will be published in peer-reviewed journals and special issues. They form a cross-section of the scientific output, either by summarising the new geoscientific picture of Mars provided by HRSC or by detailing some of the topics of data analysis concerning photogrammetry, cartography and spectral data analysis.

  14. High Resolution Global View of Io

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Io, the most volcanic body in the solar system is seen in the highest resolution obtained to date by NASA's Galileo spacecraft. The smallest features that can be discerned are 2.5 kilometers in size. There are rugged mountains several kilometers high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. The picture is centered on the side of Io that always faces away from Jupiter; north is to the top.

    Color images acquired on September 7, 1996 have been merged with higher resolution images acquired on November 6, 1996 by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. The color is composed of data taken, at a range of 487,000 kilometers, in the near-infrared, green, and violet filters and has been enhanced to emphasize the extraordinary variations in color and brightness that characterize Io's face. The high resolution images were obtained at ranges which varied from 245,719 kilometers to 403,100 kilometers.

    Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  15. High-resolution color images of Io

    NASA Technical Reports Server (NTRS)

    Mcewen, A. S.; Soderblom, L. A.

    1984-01-01

    Color versions of the highest resolution Voyager images of Io were produced by combining the low resolution color images with the high resolution, clear filter images. High resolution versions of the orange, blue, and violet filter images are produced by: orange = high-res clear * low-res orange / low-res clear blue = high-res clear * low-res blue / low-res clear violet = high-res clear * low-res violet / low-res clear. The spectral responses of the high and low resolution clear filter images cancel, leaving the color, while the spatial frequencies of the two low resolution images cancel, leaving the high resolution.

  16. Conductive resins improve charging and resolution of acquired images in electron microscopic volume imaging

    PubMed Central

    Nguyen, Huy Bang; Thai, Truc Quynh; Saitoh, Sei; Wu, Bao; Saitoh, Yurika; Shimo, Satoshi; Fujitani, Hiroshi; Otobe, Hirohide; Ohno, Nobuhiko

    2016-01-01

    Recent advances in serial block-face imaging using scanning electron microscopy (SEM) have enabled the rapid and efficient acquisition of 3-dimensional (3D) ultrastructural information from a large volume of biological specimens including brain tissues. However, volume imaging under SEM is often hampered by sample charging, and typically requires specific sample preparation to reduce charging and increase image contrast. In the present study, we introduced carbon-based conductive resins for 3D analyses of subcellular ultrastructures, using serial block-face SEM (SBF-SEM) to image samples. Conductive resins were produced by adding the carbon black filler, Ketjen black, to resins commonly used for electron microscopic observations of biological specimens. Carbon black mostly localized around tissues and did not penetrate cells, whereas the conductive resins significantly reduced the charging of samples during SBF-SEM imaging. When serial images were acquired, embedding into the conductive resins improved the resolution of images by facilitating the successful cutting of samples in SBF-SEM. These results suggest that improving the conductivities of resins with a carbon black filler is a simple and useful option for reducing charging and enhancing the resolution of images obtained for volume imaging with SEM. PMID:27020327

  17. High Resolution Neutral Atom Microscope

    NASA Astrophysics Data System (ADS)

    Bucay, Igal; Castillo-Garza, Rodrigo; Stratis, Georgios; Raizen, Mark

    2015-03-01

    We are developing a high resolution neutral atom microscope based on metastable atom electron spectroscopy (MAES). When a metastable atom of a noble gas is near a solid, a surface electron will tunnel to an empty energy level of the metastable atom, thereby ejecting the excited electron from the atom. The emitted electrons carry information regarding the local topography and electronic, magnetic, and chemical structures of most hard materials. Furthermore, using a chromatic aberration corrected magnetic hexapole lens we expect to attain a spatial resolution below 10 nm. We will use this microscope to investigate how local phenomena can give rise to macroscopic effects in materials that cannot be probed using a scanning tunneling microscope, namely insulating transition metal oxides.

  18. A high resolution TDC subsystem

    SciTech Connect

    Geiges, R.; Merle, K. )

    1994-02-01

    A high resolution TDC subsystem was developed at the Institute for Nuclear Physics in Mainz. The TDC chip offers a time resolution of less than 300 ps and a programmable measurement range from 0 to 16 [mu]sec. The time measurement is done with a new, purely digital counting method. The chip can be operated in common start or common stop mode. In common start mode the chip is able to store up to 4 multiple hits per channel. The chip is used to build a transputer controlled subsystem for the measurement of the drift times of a vertical drift chamber. The design of the subsystem will be described and the first results from the tests of the prototype system will be presented.

  19. High resolution time interval counter

    DOEpatents

    Condreva, Kenneth J.

    1994-01-01

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

  20. High resolution time interval counter

    DOEpatents

    Condreva, K.J.

    1994-07-26

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.

  1. DARPA high resolution display technologies

    NASA Astrophysics Data System (ADS)

    Slusarczuk, Marko

    1990-11-01

    Much of the information of interest to pilots in flight is display-limited, and is undergoing substantial expansion due to improved sensor output and signal processing; attention is accordingly given to digitally-based instrument display imaging in the present evaluation of high-resolution cockpit display technologies. Also noted are the advantages of digitally transmitted sensor data in cases where the airborne reconnaissance user may be able to analyze telemetered airborne data in real time and respond with requests to the pilot for more detailed information of specific battlefield sites.

  2. High-Resolution Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff; Goetz, Alexander F. H.

    1990-01-01

    Earth resources observed in greater detail. High-Resolution Imaging Spectrometer, undergoing development for use in NASA's Earth Observing System, measures reflectance of Earth's surface in visible and near-infrared wavelengths. From an orbit around Earth, instrument scans surface of Earth in 200 wavelength bands simultaneously. Produces images enabling identification of minerals in rocks and soils, important algal pigments in oceans and inland waters, changes in spectra associated with biochemistry of plant canopies, compositions of atmospheric aerosols, sizes of grains in snow, and contamination of snow by impurities that absorb visible light.

  3. High Resolution Scanning Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R. (Inventor); Miranda, Felix A. (Inventor)

    2000-01-01

    The present invention provides a High Resolution Scanning Reflectarray Antenna (HRSRA) for the purpose of tracking ground terminals and space craft communication applications. The present invention provides an alternative to using gimbaled parabolic dish antennas and direct radiating phased arrays. When compared to a gimbaled parabolic dish, the HRSRA offers the advantages of vibration free steering without incurring appreciable cost or prime power penalties. In addition, it offers full beam steering at a fraction of the cost of direct radiating arrays and is more efficient.

  4. Applications of high-resolution remote sensing image data

    NASA Technical Reports Server (NTRS)

    Strome, W. M.; Leckie, D.; Miller, J.; Buxton, R.

    1990-01-01

    There are many situations in which the image resolution of satellite data is insufficient to provide the detail required for resource management and environmental monitoring. This paper will focus on applications of high-resolution (0.4 to 10 m) airborne multispectral and imaging spectrometer data acquired in Canada using the MEIS II multispectral line imager and the PMI imaging spectrometer. Applications discussed will include forestry, mapping, and geobotany.

  5. Ultra-high resolution AMOLED

    NASA Astrophysics Data System (ADS)

    Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

    2011-06-01

    AMOLED microdisplays continue to show improvement in resolution and optical performance, enhancing their appeal for a broad range of near-eye applications such as night vision, simulation and training, situational awareness, augmented reality, medical imaging, and mobile video entertainment and gaming. eMagin's latest development of an HDTV+ resolution technology integrates an OLED pixel of 3.2 × 9.6 microns in size on a 0.18 micron CMOS backplane to deliver significant new functionality as well as the capability to implement a 1920×1200 microdisplay in a 0.86" diagonal area. In addition to the conventional matrix addressing circuitry, the HDTV+ display includes a very lowpower, low-voltage-differential-signaling (LVDS) serialized interface to minimize cable and connector size as well as electromagnetic emissions (EMI), an on-chip set of look-up-tables for digital gamma correction, and a novel pulsewidth- modulation (PWM) scheme that together with the standard analog control provides a total dimming range of 0.05cd/m2 to 2000cd/m2 in the monochrome version. The PWM function also enables an impulse drive mode of operation that significantly reduces motion artifacts in high speed scene changes. An internal 10-bit DAC ensures that a full 256 gamma-corrected gray levels are available across the entire dimming range, resulting in a measured dynamic range exceeding 20-bits. This device has been successfully tested for operation at frame rates ranging from 30Hz up to 85Hz. This paper describes the operational features and detailed optical and electrical test results for the new AMOLED WUXGA resolution microdisplay.

  6. A simple, high efficiency, high resolution spectropolarimeter

    NASA Astrophysics Data System (ADS)

    Barden, Samuel C.

    2012-09-01

    A simple concept is described that uses volume phase holographic gratings as polarizing dispersers for a high efficiency, high resolution spectropolarimeter. Although the idea has previously been mentioned in the literature as possible, such a concept has not been explored in detail. Performance analysis is presented for a VPHG spectropolarimeter concept that could be utilized for both solar and night-time astronomy. Instrumental peak efficiency can approach 100% with spectral dispersions permitting R~200,000 spectral resolution with diffraction limited telescopes. The instrument has 3-channels: two dispersed image planes with orthogonal polarization and an undispersed image plane. The concept has a range of versatility where it could be configured (with appropriate half-wave plates) for slit-fed spectroscopy or without slits for snapshot/hyperspectral/tomographic spectroscopic imaging. Multiplex gratings could also be used for the simultaneous recording of two separate spectral bands or multiple instruments could be daisy chained with beam splitters for further spectral coverage.

  7. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Venkataraman, Malathy Devi

    2003-01-01

    Spectroscopic parameters (such as line position, intensity, broadening and shifting coefficients and their temperature dependences, line mixing coefficients etc.) for various molecular species of atmospheric interest are determined. In order to achieve these results, infrared spectra of several molecular bands are obtained using high-resolution recording instruments such as tunable diode laser spectrometer and Fourier transform spectrometers. Using sophisticated analysis routines (Multispectrum nonlinear least squares technique) these high-resolution infrared spectra are processed to determine the various spectral line parameters that are cited above. Spectra were taken using the McMath-Pierce Fourier transform spectrometer (FTS) at the National Solar Observatory on Kitt Peak, Arizona as well as the Bruker FTS at the Pacific Northwest National Laboratory (PNNL) at Richland, Washington. Most of the spectra are acquired not only at room temperature, but also at several different cold temperatures. This procedure is necessary to study the variation of the spectral line parameters as a function of temperature in order to simulate the Earth's and other planetary atmospheric environments. Depending upon the strength or weakness of the various bands recorded and analyzed, the length(s) of the absorption cells in which the gas samples under study are kept varied from a few centimeters up to several meters and the sample temperatures varied from approximately +30 C to -63 C. Research on several infrared bands of various molecular species and their isotopomers are undertaken. Those studies are briefly described.

  8. Solar corona at high resolution

    NASA Technical Reports Server (NTRS)

    Golub, L.; Rosner, R.; Zombeck, M. V. Z.; Vaiana, G. S.

    1982-01-01

    The earth's surface is shielded from solar X rays almost completely by the atmosphere. It is, therefore, necessary to place X-ray detectors on rockets or orbiting satellites. Solar rays were detected for the first time in the late 1940's, using V-2 rockets. In 1960, the first true X-ray images of the sun were obtained with the aid of a simple pinhole camera. The spatial resolution of the X-ray images could be considerably improved by making use of reflective optics, operating at grazing incidence. Aspects of X-ray mirror developments are discussed along with the results obtained in coronal studies utilizing the new devices for the observation of solar X-ray emission. It is pointed out that the major achievements of the Skylab missions were due primarily to the unique opportunity to obtain data over an extended period of time. Attention is given to normal incidence X-ray optics, achievements possible by making use of high spatial resolution optics, and details of improved mirror design.

  9. High resolution imaging at Palomar

    NASA Technical Reports Server (NTRS)

    Kulkarni, Shrinivas R.

    1992-01-01

    For the last two years we have embarked on a program of understanding the ultimate limits of ground-based optical imaging. We have designed and fabricated a camera specifically for high resolution imaging. This camera has now been pressed into service at the prime focus of the Hale 5 m telescope. We have concentrated on two techniques: the Non-Redundant Masking (NRM) and Weigelt's Fully Filled Aperture (FFA) method. The former is the optical analog of radio interferometry and the latter is a higher order extension of the Labeyrie autocorrelation method. As in radio Very Long Baseline Interferometry (VLBI), both these techniques essentially measure the closure phase and, hence, true image construction is possible. We have successfully imaged binary stars and asteroids with angular resolution approaching the diffraction limit of the telescope and image quality approaching that of a typical radio VLBI map. In addition, we have carried out analytical and simulation studies to determine the ultimate limits of ground-based optical imaging, the limits of space-based interferometric imaging, and investigated the details of imaging tradeoffs of beam combination in optical interferometers.

  10. High-resolution slug testing.

    PubMed

    Zemansky, G M; McElwee, C D

    2005-01-01

    The hydraulic conductivity (K) variation has important ramifications for ground water flow and the transport of contaminants in ground water. The delineation of the nature of that variation can be critical to complete characterization of a site and the planning of effective and efficient remedial measures. Site-specific features (such as high-conductivity zones) need to be quantified. Our alluvial field site in the Kansas River valley exhibits spatial variability, very high conductivities, and nonlinear behavior for slug tests in the sand and gravel aquifer. High-resolution, multilevel slug tests have been performed in a number of wells that are fully screened. A general nonlinear model based on the Navier-Stokes equation, nonlinear frictional loss, non-Darcian flow, acceleration effects, radius changes in the wellbore, and a Hvorslev model for the aquifer has been used to analyze the data, employing an automated processing system that runs within the Excel spreadsheet program. It is concluded that slug tests can provide the necessary data to identify the nature of both horizontal and vertical K variation in an aquifer and that improved delineation or higher resolution of K structure is possible with shorter test intervals. The gradation into zones of higher conductivity is sharper than seen previously, and the maximum conductivity observed is greater than previously measured. However, data from this project indicate that well development, the presence of fines, and the antecedent history of the well are important interrelated factors in regard to slug-test response and can prevent obtaining consistent results in some cases.

  11. High Resolution Thermography In Medicine

    NASA Astrophysics Data System (ADS)

    Clark, R. P.; Goff, M. R.; Culley, J. E.

    1988-10-01

    A high resolution medical thermal imaging system using an 8 element SPRI1E detector is described. Image processing is by an Intellect 100 processor and is controlled by a DEC LSI 11/23 minicomputer. Image storage is with a 170 Mbyte winchester disc together with archival storage on 12 inch diameter optical discs having a capacity of 1 Gbyte per side. The system is currently being evaluated for use in physiology and medicine. Applications outlined include the potential of thermographic screening to identify genetic carriers in X-linked hypohidrotic ectodermal dysplasia (XED), detailed vas-cular perfusion studies in health and disease and the relation-ship between cutaneous blood flow, neurological peripheral function and skin surface temperature.

  12. Highest Resolution Image of Dust and Sand Yet Acquired on Mars

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Click on image for Figure 1Click on image for Figure 2Click on image for Figure 3

    This mosaic of four side-by-side microscope images (one a color composite) was acquired by the Optical Microscope, a part of the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument suite on NASA's Phoenix Mars Lander. Taken on the ninth Martian day of the mission, or Sol 9 (June 3, 2008), the image shows a 3 millimeter (0.12 inch) diameter silicone target after it has been exposed to dust kicked up by the landing. It is the highest resolution image of dust and sand ever acquired on Mars. The silicone substrate provides a sticky surface for holding the particles to be examined by the microscope.

    Martian Particles on Microscope's Silicone Substrate In figure 1, the particles are on a silcone substrate target 3 millimeters (0.12 inch) in diameter, which provides a sticky surface for holding the particles while the microscope images them. Blow-ups of four of the larger particles are shown in the center. These particles range in size from about 30 microns to 150 microns (from about one one-thousandth of an inch to six one-thousandths of an inch).

    Possible Nature of Particles Viewed by Mars Lander's Optical Microscope In figure 2, the color composite on the right was acquired to examine dust that had fallen onto an exposed surface. The translucent particle highlighted at bottom center is of comparable size to white particles in a Martian soil sample (upper pictures) seen two sols earlier inside the scoop of Phoenix's Robotic Arm as imaged by the lander's Robotic Arm Camera. The white particles may be examples of the abundant salts that have been found in the Martian soil by previous missions. Further investigations will be needed to determine the white material's composition and whether translucent particles

  13. Evaluation of Advanced Bionics high resolution mode.

    PubMed

    Buechner, Andreas; Frohne-Buechner, Carolin; Gaertner, Lutz; Lesinski-Schiedat, Anke; Battmer, Rolf-Dieter; Lenarz, Thomas

    2006-07-01

    The objective of this paper is to evaluate the advantages of the Advanced Bionic high resolution mode for speech perception, through a retrospective analysis. Forty-five adult subjects were selected who had a minimum experience of three months' standard mode (mean of 10 months) before switching to high resolution mode. Speech perception was tested in standard mode immediately before fitting with high resolution mode, and again after a maximum of six months high resolution mode usage (mean of two months). A significant improvement was found, between 11 and 17%, depending on the test material. The standard mode preference does not give any indication about the improvement when switching to high resolution. Users who are converted within any study achieve a higher performance improvement than those converted in the clinical routine. This analysis proves the significant benefits of high resolution mode for users, and also indicates the need for guidelines for individual optimization of parameter settings in a high resolution mode program.

  14. Acquiring high-rate neural spike data with hardware-constrained embedded sensors.

    PubMed

    Farshchi, Shahin; Pesterev, Aleksey; Ho, Wan-Lun; Judy, Jack W

    2006-01-01

    In an effort to enable embedded sensors that are hardware and bandwidth constrained to acquire high- frequency neural signals, signal-filtering and signal- compression algorithms have been implemented and tested on a commercial-off-the-shelf embedded-system platform. The sensor modules have been programmed to acquire, filter, and transmit raw biological signals at a rate of 32 kbps. Furthermore, on-board signal processing enables one channel sampled at a rate of 4 kS/s at 12-bit resolution to be compressed via ADPCM and transmitted in real time. In addition, the sensors can be configured to only transmit individual time-referenced "spike" waveforms, or only the spike parameters for alleviating network traffic and increasing battery life. PMID:17945608

  15. High resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, Jim; Dinyari, Rostam; Huie, Phil; Butterwick, Alex; Peumans, Peter; Palanker, Daniel

    2009-02-01

    Electronic retinal prostheses seek to restore sight in patients with retinal degeneration by delivering pulsed electric currents to retinal neurons via an array of microelectrodes. Most implants use inductive or optical transmission of information and power to an intraocular receiver, with decoded signals subsequently distributed to retinal electrodes through an intraocular cable. Surgical complexity could be minimized by an "integrated" prosthesis, in which both power and data are delivered directly to the stimulating array without any discrete components or cables. We present here an integrated retinal prosthesis system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a video goggle projection system operating at near-infrared wavelengths (~ 900 nm). Photodiodes convert light into pulsed electric current, with charge injection maximized by specially optimized series photodiode circuits. Prostheses of three different pixel densities (16 pix/mm2, 64 pix/mm2, and 256 pix/mm2) have been designed, simulated, and prototyped. Retinal tissue response to subretinal implants made of various materials has been investigated in RCS rats. The resulting prosthesis can provide sufficient charge injection for high resolution retinal stimulation without the need for implantation of any bulky discrete elements such as coils or tethers. In addition, since every pixel functions independently, pixel arrays may be placed separately in the subretinal space, providing visual stimulation to a larger field of view.

  16. Planetary Atmospheres at High Resolution

    NASA Astrophysics Data System (ADS)

    Gurwell, M.; Butler, B.; Moullet, A.

    2013-10-01

    The long millimeter through submillimeter bands are particularly well suited for studying the wide variety of planetary atmospheres in our solar system. Temperatures ranging from a few 10s to hundreds of degrees, coupled with typically high densities (relative to the ISM) mean that thermal ‘continuum’ emission can be strong and molecular rotational transitions can be well-populated. Large bodies (Jovian and terrestrial planets) can be reasonably well studied by current interferometers such as the Submillimeter Array, IRAM Plateau de Bure Interferometer, and Combined Array for Research in Millimeter-wave Astronomy, yet many smaller bodies with atmospheres can only be crudely studied, primarily due to lack of sensitivity on baselines long enough to well resolve the object. Newly powerful interferometers such as the Atacama Large Millimeter/Submillimeter Array will usher in a new era of planetary atmospheric exploration. The vast sensitivity and spatial resolution of these arrays will increase our ability to image all bodies with extremely fine fidelity (due to the large number of antennas), and for study of smaller objects by resolving their disks into many pixels while providing the sensitivity necessary to detect narrow and/or weak line emission. New science topics will range from detailed mapping of HDO, ClO, and sulfur species in the mesosphere of Venus and PH3 and H2S in the upper tropospheres of the gas and ice giants, high SNR mapping of winds on Mars, Neptune and Titan, down to spectroscopic imaging of volcanic eruptions within the tenuous atmosphere on Io, resolved imaging of CO and other species in the atmosphere of Pluto, and even potentially detection of gases within the plumes of Enceladus.

  17. High Resolution, High Frame Rate Video Technology

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Papers and working group summaries presented at the High Resolution, High Frame Rate Video (HHV) Workshop are compiled. HHV system is intended for future use on the Space Shuttle and Space Station Freedom. The Workshop was held for the dual purpose of: (1) allowing potential scientific users to assess the utility of the proposed system for monitoring microgravity science experiments; and (2) letting technical experts from industry recommend improvements to the proposed near-term HHV system. The following topics are covered: (1) State of the art in the video system performance; (2) Development plan for the HHV system; (3) Advanced technology for image gathering, coding, and processing; (4) Data compression applied to HHV; (5) Data transmission networks; and (6) Results of the users' requirements survey conducted by NASA.

  18. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Venkataraman, Malathy Devi

    2006-01-01

    The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as H2O (water vapor), O3 (ozone), HCN (hydrogen cyanide), CH4 (methane), NO2 (nitrogen dioxide) and CO (carbon monoxide). The data required for the analyses were obtained from two different Fourier Transform Spectrometers (FTS); one of which is located at the National Solar Observatory (NSO) on Kitt Peak, Arizona and the other instrument is located at the Pacific Northwest National Laboratories (PNNL) at Richland, Washington. The data were analyzed using a modified multispectrum nonlinear least squares fitting algorithm developed by Dr. D. Chris Benner of the College of William and Mary. The results from these studies made significant improvements in the line positons and intensities for these molecules. The measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced shift coefficients for hundreds of infrared transitions of HCN, CO3 CH4 and H2O were also performed during this period. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research Satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon- and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields. The research conducted during the period 2003-2006 has resulted in publications given in this paper. In addition to Journal publications, several oral and poster presentations were given at various Scientific conferences within the United States

  19. Clementine High Resolution Camera Mosaicking Project

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This report constitutes the final report for NASA Contract NASW-5054. This project processed Clementine I high resolution images of the Moon, mosaicked these images together, and created a 22-disk set of compact disk read-only memory (CD-ROM) volumes. The mosaics were produced through semi-automated registration and calibration of the high resolution (HiRes) camera's data against the geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic produced by the US Geological Survey (USGS). The HiRes mosaics were compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution nadir-looking observations. The images were spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel for sub-polar mosaics (below 80 deg. latitude) and using the stereographic projection at a scale of 30 m/pixel for polar mosaics. Only images with emission angles less than approximately 50 were used. Images from non-mapping cross-track slews, which tended to have large SPICE errors, were generally omitted. The locations of the resulting image population were found to be offset from the UV/Vis basemap by up to 13 km (0.4 deg.). Geometric control was taken from the 100 m/pixel global and 150 m/pixel polar USGS Clementine Basemap Mosaics compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Radiometric calibration was achieved by removing the image nonuniformity dominated by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap, that approximately transform the 8-bit HiRes data to photometric units. The sub-polar mosaics are divided into tiles that cover approximately 1.75 deg. of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. Polar mosaics are tiled into squares 2250 pixels on a

  20. Clementine High Resolution Camera Mosaicking Project

    NASA Astrophysics Data System (ADS)

    1998-10-01

    This report constitutes the final report for NASA Contract NASW-5054. This project processed Clementine I high resolution images of the Moon, mosaicked these images together, and created a 22-disk set of compact disk read-only memory (CD-ROM) volumes. The mosaics were produced through semi-automated registration and calibration of the high resolution (HiRes) camera's data against the geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic produced by the US Geological Survey (USGS). The HiRes mosaics were compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution nadir-looking observations. The images were spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel for sub-polar mosaics (below 80 deg. latitude) and using the stereographic projection at a scale of 30 m/pixel for polar mosaics. Only images with emission angles less than approximately 50 were used. Images from non-mapping cross-track slews, which tended to have large SPICE errors, were generally omitted. The locations of the resulting image population were found to be offset from the UV/Vis basemap by up to 13 km (0.4 deg.). Geometric control was taken from the 100 m/pixel global and 150 m/pixel polar USGS Clementine Basemap Mosaics compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Radiometric calibration was achieved by removing the image nonuniformity dominated by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap, that approximately transform the 8-bit HiRes data to photometric units. The sub-polar mosaics are divided into tiles that cover approximately 1.75 deg. of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. Polar mosaics are tiled into squares 2250 pixels on a

  1. A Procedure for High Resolution Satellite Imagery Quality Assessment

    PubMed Central

    Crespi, Mattia; De Vendictis, Laura

    2009-01-01

    Data products generated from High Resolution Satellite Imagery (HRSI) are routinely evaluated during the so-called in-orbit test period, in order to verify if their quality fits the desired features and, if necessary, to obtain the image correction parameters to be used at the ground processing center. Nevertheless, it is often useful to have tools to evaluate image quality also at the final user level. Image quality is defined by some parameters, such as the radiometric resolution and its accuracy, represented by the noise level, and the geometric resolution and sharpness, described by the Modulation Transfer Function (MTF). This paper proposes a procedure to evaluate these image quality parameters; the procedure was implemented in a suitable software and tested on high resolution imagery acquired by the QuickBird, WorldView-1 and Cartosat-1 satellites. PMID:22412312

  2. High-Resolution Cassini RADAR Scatterometer Images of Titan's Surface

    NASA Astrophysics Data System (ADS)

    Wye, Lauren C.; Zebker, H. A.; Cassini RADAR Team

    2006-09-01

    The Cassini RADAR scatterometer has acquired observations to date of about 40% of Titan's surface at resolutions averaging just under 100 km, where the resolution cell size is set by the real aperture of the radar antenna. Finer resolution (0.3-1 km) images have been acquired by RADAR in synthetic-aperture (SAR) mode of about 10% of the surface. Additional techniques have been developed to use the SAR processor at larger distances (denoted High-SAR) for increased high-resolution (2-3 km) coverage, though with very narrow swath sizes (see West et al., this conference). In this paper, we demonstrate that complex processing methods, specifically range compression and unfocused SAR processing, can also be applied to the data collected in rastered scatterometer mode, achieving resolutions near 15 km and maintaining 10 or more radar "looks.” Despite poorer resolution, rastered scatterometry has two advantages over SAR and High-SAR: 1) greater surface coverage is possible with less data volume, and 2) the surface is sampled over a wider range of incidence angles, so that important characteristics like dielectric constant and surface slope may be estimated. Improving the resolution of the scatterometer's near-global backscatter maps will significantly enhance the unique knowledge that RADAR contributes to the understanding of Titan and its fascinating surface. Here, we present examples of scatterometer coverage of Titan at its highest resolution. This work was carried out at Stanford University, under contract with the Cassini Project of the Jet Propulsion Laboratory (JPL) / National Aeronautics and Space Administration (NASA).

  3. The high resolution imaging spectrometer (HIRIS) for EOS

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Herring, Mark

    1989-01-01

    The high resolution imaging spectrometer (HIRIS) designed for the Earth Observing System (EOS) is designed to acquire images in 192 spectral bands simultaneously in the 0.4-2.5-micron wavelength region. HIRIS is a targeting rather than a continuous acquisition instrument and obtains high-spatial- and spectral-resolution images in a 30-km swath with a 30-m ground instantaneous field of view (GIFOV) in vertical viewing. Pointing will allow image acquisition at -30 to +60 deg along-track and +/-24 deg cross-track. The raw data rate of the instrument is 512 Mbs. The high spectral resolution will make it possible to identify many surficial materials such as rocks, soils, and suspended matter in water directly. HIRIS also offers the possibility of studying biochemical process in vegetation canopies.

  4. High resolution magnetic spectrometer SHARAQ in RIBF

    SciTech Connect

    Shimoura, S.

    2007-05-22

    For a new spectroscopy of nuclei using intense RI beams at RIBF, we started the SHARAQ project where a high-resolution SHARAQ spectrometer is being constructed together with a high-resolution secondary beam line. Physics motivation and the specification of the spectrometer are presented.

  5. High resolution scintillation detector with semiconductor readout

    DOEpatents

    Levin, Craig S.; Hoffman, Edward J.

    2000-01-01

    A novel high resolution scintillation detector array for use in radiation imaging such as high resolution Positron Emission Tomography (PET) which comprises one or more parallelepiped crystals with at least one long surface of each crystal being in intimate contact with a semiconductor photodetector such that photons generated within each crystal by gamma radiation passing therethrough is detected by the photodetector paired therewith.

  6. High Resolution PDF Measurements on Ag Nanoparticles

    SciTech Connect

    Rocha, Tulio C. R.; Martin, Chris; Kycia, Stefan; Zanchet, Daniela

    2009-01-29

    The quantitative analysis of structural defects in Ag nanoparticles was addressed in this work. We performed atomic scale structural characterization by a combination of x-ray diffraction (XRD) using the Pair Distribution Function analysis (PDF) and High Resolution Transmission Electron Microscopy (HRTEM). The XRD measurements were performed using an innovative instrumentation setup to provide high resolution PDF patterns.

  7. High Resolution Imaging with AEOS

    SciTech Connect

    Patience, J; Macintosh, B A; Max, C E

    2001-08-27

    The U. S. Air Force Advanced Electro-Optical System (AEOS) which includes a 941 actuator adaptive optics system on a 3.7m telescope has recently been made available for astronomical programs. Operating at a wavelength of 750 nm, the diffraction-limited angular resolution of the system is 0.04 inches; currently, the magnitude limit is V {approx} 7 mag. At the distances of nearby open clusters, diffraction-limited images should resolve companions with separations as small as 4-6 AU--comparable to the Sun-Jupiter distance. The ability to study such close separations is critical, since most companions are expected to have separations in the few AU to tens of AU range. With the exceptional angular resolution of the current AEOS setup, but restricted target magnitude range, we are conducting a companion search of a large, well-defined sample of bright early-type stars in nearby open clusters and in the field. Our data set will both characterize this relatively new adaptive optics system and answer questions in binary star formation and stellar X-ray activity. We will discuss our experience using AEOS, the data analysis involved, and our initial results.

  8. High spectral resolution in the solar spectrum

    NASA Technical Reports Server (NTRS)

    Baret, F.; Green, R. O.

    1994-01-01

    A session dedicated to high spectral resolution in the solar spectrum, covering topics of calibration, atmospheric correction, geology/pedology, inland water, and vegetation, is reported. The session showed a high degree of diversity in the topics and the approaches used. It was highlighted that high spectral resolution data could provide atmospherically corrected ground level calibrated reflectance values. Important advances were shown in the use of radiative transfer models applied either on water bodies or vegetation. Several studies highlighted the high degree of redundancy contained in high spectral resolution data.

  9. High-Resolution Mammography Detector Employing Optical Switching Readout

    NASA Astrophysics Data System (ADS)

    Irisawa, Kaku; Kaneko, Yasuhisa; Yamane, Katsutoshi; Sendai, Tomonari; Hosoi, Yuichi

    Conceiving a new detector structure, FUJIFILM Corporation has successfully put its invention of an X-ray detector employing "Optical Switching" into practical use. Since Optical Switching Technology allows an electrode structure to be easily designed, both high resolution of pixel pitch and low electrical noise readout have been achieved, which have consequently realized the world's smallest pixel size of 50×50 μm2 from a Direct-conversion FPD system as well as high DQE. The digital mammography system equipped with this detector enables to acquire high definition images while maintaining granularity. Its outstanding feature is to be able to acquire high-precision images of microcalcifications which is an important index in breast examination.

  10. Development of Global 30m Resolution Water Body Map with Permanent/Temporal Water Body Separation Using Satellite Acquired Images of Landsat GLS Datasets

    NASA Astrophysics Data System (ADS)

    Ikeshima, D.; Yamazaki, D.; Yoshikawa, S.; Kanae, S.

    2015-12-01

    The specification of worldwide water body distribution is important for discovering hydrological cycle. Global 3-second Water Body Map (G3WBM) is a global scale map, which indicates the distribution of water body in 90m resolutions (http://hydro.iis.u-tokyo.ac.jp/~yamadai/G3WBM/index.html). This dataset was mainly built to identify the width of river channels, which is one of major uncertainties of continental-scale river hydrodynamics models. To survey the true width of the river channel, this water body map distinguish Permanent Water Body from Temporary Water Body, which means separating river channel and flood plain. However, rivers with narrower width, which is a major case in usual river, could not be observed in this map. To overcome this problem, updating the algorithm of G3WBM and enhancing the resolutions to 30m is the goal of this research. Although this 30m-resolution water body map uses similar algorithm as G3WBM, there are many technical issues attributed to relatively high resolutions. Those are such as lack of same high-resolution digital elevation map, or contamination problem of sub-pixel scale object on satellite acquired image, or invisibility of well-vegetated water body such as swamp. To manage those issues, this research used more than 30,000 satellite images of Landsat Global Land Survey (GLS), and lately distributed topography data of Shuttle Rader Topography Mission (SRTM) 1 arc-second (30m) digital elevation map. Also the effect of aerosol, which would scatter the sun reflectance and disturb the acquired result image, was considered. Due to these revises, the global water body distribution was established in more precise resolution.

  11. High-Resolution Vibration-Rotation Spectroscopy of CO[subscript 2]: Understanding the Boltzmann Distribution

    ERIC Educational Resources Information Center

    Castle, Karen J.

    2007-01-01

    In this undergraduate physical chemistry laboratory experiment, students acquire a high-resolution infrared absorption spectrum of carbon dioxide and use their data to show that the rotational-vibrational state populations follow a Boltzmann distribution. Data are acquired with a mid-infrared laser source and infrared detector. Appropriate…

  12. A methodology for high resolution digital image correlation in high temperature experiments.

    PubMed

    Blaber, Justin; Adair, Benjamin S; Antoniou, Antonia

    2015-03-01

    We propose a methodology for performing high resolution Digital Image Correlation (DIC) analysis during high-temperature mechanical tests. Specifically, we describe a technique for producing a stable, high-quality pattern on metal surfaces along with a simple optical system that uses a visible-range camera and a long-range microscope. The results are analyzed with a high-quality open-source DIC software developed by us. Using the proposed technique, we successfully acquired high-resolution strain maps of the crack tip field in a nickel superalloy sample at 1000 °C. PMID:25832279

  13. High range resolution micro-Doppler analysis

    NASA Astrophysics Data System (ADS)

    Cammenga, Zachary A.; Smith, Graeme E.; Baker, Christopher J.

    2015-05-01

    This paper addresses use of the micro-Doppler effect and the use of high range-resolution profiles to observe complex targets in complex target scenes. The combination of micro-Doppler and high range-resolution provides the ability to separate the motion of complex targets from one another. This ability leads to the differentiation of targets based on their micro-Doppler signatures. Without the high-range resolution, this would not be possible because the individual signatures would not be separable. This paper also addresses the use of the micro-Doppler information and high range-resolution profiles to generate an approximation of the scattering properties of a complex target. This approximation gives insight into the structure of the complex target and, critically, is created without using a pre-determined target model.

  14. NOAA's Use of High-Resolution Imagery

    NASA Technical Reports Server (NTRS)

    Hund, Erik

    2007-01-01

    NOAA's use of high-resolution imagery consists of: a) Shoreline mapping and nautical chart revision; b) Coastal land cover mapping; c) Benthic habitat mapping; d) Disaster response; and e) Imagery collection and support for coastal programs.

  15. High-Resolution X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Brissenden, Roger J.; Davis, William; Elsner, Ronald F.; Elvis, Martin; Freeman, Mark; Gaetz, Terry; Gorenstein, Paul; Gubarev, Mikhail V.

    2010-01-01

    Fundamental needs for future x-ray telescopes: a) Sharp images => excellent angular resolution. b) High throughput => large aperture areas. Generation-X optics technical challenges: a) High resolution => precision mirrors & alignment. b) Large apertures => lots of lightweight mirrors. Innovation needed for technical readiness: a) 4 top-level error terms contribute to image size. b) There are approaches to controlling those errors. Innovation needed for manufacturing readiness. Programmatic issues are comparably challenging.

  16. High Resolution Aircraft Scanner Mapping of Geothermal and Volcanic Areas

    SciTech Connect

    Mongillo, M.A.; Cochrane, G.R.; Wood, C.P.; Shibata, Y.

    1995-01-01

    High spectral resolution GEOSCAN Mkll multispectral aircraft scanner imagery has been acquired, at 3-6 m spatial resolutions, over much of the Taupo Volcanic Zone as part of continuing investigations aimed at developing remote sensing techniques for exploring and mapping geothermal and volcanic areas. This study examined the 24-band: visible, near-IR (NIR), mid-IR (MIR) and thermal-IR (TIR) imagery acquired over Waiotapu geothermal area (3 m spatial resolution) and White Island volcano (6 m resolution). Results show that color composite images composed of visible and NIR wavelengths that correspond to color infrared (CIR) photographic wavelengths can be useful for distinguishing among bare ground, water and vegetation features and, in certain cases, for mapping various vegetation types. However, combinations which include an MIR band ({approx} 2.2 {micro}m) with either visible and NIR bands, or two NIR bands, are the most powerful for mapping vegetation types, water bodies, and bare and hydrothermally altered ground. Combinations incorporating a daytime TIR band with NIR and MIR bands are also valuable for locating anomalously hot features and distinguishing among different types of surface hydrothermal alteration.

  17. Cheetah: A high frame rate, high resolution SWIR image camera

    NASA Astrophysics Data System (ADS)

    Neys, Joel; Bentell, Jonas; O'Grady, Matt; Vermeiren, Jan; Colin, Thierry; Hooylaerts, Peter; Grietens, Bob

    2008-10-01

    A high resolution, high frame rate InGaAs based image sensor and associated camera has been developed. The sensor and the camera are capable of recording and delivering more than 1700 full 640x512pixel frames per second. The FPA utilizes a low lag CTIA current integrator in each pixel, enabling integration times shorter than one microsecond. On-chip logics allows for four different sub windows to be read out simultaneously at even higher rates. The spectral sensitivity of the FPA is situated in the SWIR range [0.9-1.7 μm] and can be further extended into the Visible and NIR range. The Cheetah camera has max 16 GB of on-board memory to store the acquired images and transfer the data over a Gigabit Ethernet connection to the PC. The camera is also equipped with a full CameralinkTM interface to directly stream the data to a frame grabber or dedicated image processing unit. The Cheetah camera is completely under software control.

  18. High spectral resolution reflectance spectroscopy of minerals

    NASA Technical Reports Server (NTRS)

    Clark, Roger N.; King, Trude V. V.; Klejwa, Matthew; Swayze, Gregg A.; Vergo, Norma

    1990-01-01

    The reflectance spectra of minerals are studied as a function of spectral resolution in the range from 0.2 to 3.0 microns. Selected absorption bands were studied at resolving powers as high as 2240. At resolving powers of approximately 1000, many OH-bearing minerals show diagnostic sharp absorptions at the resolution limit. At low resolution, some minerals may not be distinguishable, but as the resolution is increased, most can be easily identified. As the resolution is increased, many minerals show fine structure, particularly in the OH-stretching overtone region near 1.4 micron. The fine structure can enhance the ability to discriminate between minerals, and in some cases the fine structure can be used to determine elemental composition.

  19. High resolution SAR applications and instrument design

    NASA Technical Reports Server (NTRS)

    Dionisio, C.; Torre, A.

    1993-01-01

    The Synthetic Aperture Radar (SAR) has viewed, in the last two years, a huge increment of interest from many preset and potential users. The good spatial resolution associated to the all weather capability lead to considering SAR not only a scientific instrument but a tool for verifying and controlling the daily human relationships with the Earth Environment. New missions were identified for SAR as spatial resolution became lower than three meters: disasters, pollution, ships traffic, volcanic eruptions, earthquake effect are only a few of the possible objects which can be effectively detected, controlled and monitored by SAR mounted on satellites. High resolution radar design constraints and dimensioning are discussed.

  20. High-resolution climate simulation using CAM

    NASA Astrophysics Data System (ADS)

    Bacmeister, J.; Neale, R. B.; Hannay, C.; Lauritzen, P. H.; Wehner, M. F.

    2012-12-01

    Thanks to the development of highly scalable dynamical cores that can exploit massively parallel computer architectures, we expect that global climate models in the next decade will run routinely at horizontal resolutions of 25 km or finer. Early results at these resolutions show clear improvements in simulating climatologically and societally-important mesoscale meteorology such as tropical cyclones. Improvements in regional circulations likely associated with topography are also obtained. Nevertheless many long-standing biases in climate simulations, e.g., the "double ITCZ" bias in precipitation, remain remarkably insensitive to increased resolution. This talk will present high-resolution global simulations using the community atmosphere model. Sensitivity of tropical cyclone climatology and precipitation statistics to model physics suites will be shown

  1. Black phosphorus photodetector for multispectral, high-resolution imaging.

    PubMed

    Engel, Michael; Steiner, Mathias; Avouris, Phaedon

    2014-11-12

    Black phosphorus is a layered semiconductor that is intensely researched in view of applications in optoelectronics. In this letter, we investigate a multilayer black phosphorus photodetector that is capable of acquiring high-contrast (V > 0.9) images both in the visible (λVIS = 532 nm) as well as in the infrared (λIR = 1550 nm) spectral regime. In a first step, by using photocurrent microscopy, we map the active area of the device and we characterize responsivity and gain. In a second step, by deploying the black phosphorus device as a point-like detector in a confocal microsope setup, we acquire diffraction-limited optical images with submicron resolution. The results demonstrate the usefulness of black phosphorus as an optoelectronic material for hyperspectral imaging applications.

  2. High-resolution speckle imaging through strong atmospheric turbulence.

    PubMed

    Hope, Douglas A; Jefferies, Stuart M; Hart, Michael; Nagy, James G

    2016-05-30

    We demonstrate that high-resolution imaging through strong atmospheric turbulence can be achieved by acquiring data with a system that captures short exposure ("speckle") images using a range of aperture sizes and then using a bootstrap multi-frame blind deconvolution restoration process that starts with the smallest aperture data. Our results suggest a potential paradigm shift in how we image through atmospheric turbulence. No longer should image acquisition and post processing be treated as two independent processes: they should be considered as intimately related.

  3. Gemini high-resolution optical spectrograph conceptual design

    NASA Astrophysics Data System (ADS)

    Szeto, Kei; McConnachie, Alan; Anthony, André; Bohlender, David; Crampton, David; Desaulniers, Pierre; Dunn, Jennifer; Hardy, Tim; Hill, Alexis; Monin, Dmitry; Pazder, John; Schwab, Christian; Spano, Paola; Starkenburg, Else; Thibault, Simon; Walker, Gordon; Venn, Kim; Zhang, Hu

    2012-09-01

    A multiplexed moderate resolution (R = 34,000) and a single object high resolution (R = 90,000) spectroscopic facility for the entire 340 - 950nm wavelength region has been designed for Gemini. The result is a high throughput, versatile instrument that will enable precision spectroscopy for decades to come. The extended wavelength coverage for these relatively high spectral resolutions is achieved by use of an Echelle grating with VPH cross-dispersers and for the R = 90,000 mode utilization of an image slicer. The design incorporates a fast, efficient, reliable system for acquiring targets over the7 arcmin field of Gemini. This paper outlines the science case development and requirements flow-down process that leads to the configuration of the HIA instrument and describes the overall GHOS conceptual design. In addition, this paper discusses design trades examined during the conceptual design study instrument group of the Herzberg Institute of Astrophysics has been commissioned by the Gemini Observatory as one of the three competing organizations to conduct a conceptual design study for a new Gemini High-Resolution Optical Spectrograph (GHOS). This paper outlines the science case development and requirements flow-down process that leads to the configuration of the HIA instrument and describes the overall GHOS conceptual design. In addition, this paper discusses design trades examined during the conceptual design study.

  4. Solar system events at high spatial resolution

    SciTech Connect

    Baines, K H; Gavel, D T; Getz, A M; Gibbartd, S G; MacIntosh, B; Max, C E; McKay, C P; Young, E F; de Pater, I

    1999-02-19

    Until relatively recent advances in technology, astronomical observations from the ground were limited in image resolution by the blurring effects of earth's atmosphere. The blur extent, ranging typically from 0.5 to 2 seconds of arc at the best astronomical sights, precluded ground-based observations of the details of the solar system's moons, asteroids, and outermost planets. With the maturing of a high resolution image processing technique called speckle imaging the resolution limitation of the atmosphere can now be largely overcome. Over the past three years they have used speckle imaging to observe Titan, a moon of Saturn with an atmospheric density comparable to Earth's, Io, the volcanically active innermost moon of Jupiter, and Neptune, a gas giant outer planet which has continually changing planet-encircling storms. These observations were made at the world's largest telescope, the Keck telescope in Hawaii and represent the highest resolution infrared images of these objects ever taken.

  5. High resolution solar X-ray studies

    NASA Technical Reports Server (NTRS)

    Blake, R. L.

    1974-01-01

    Two high resolution solar X-ray payloads and their launches on Aerobee rockets with pointing system are described. The payloads included 5 to 25A X-ray spectrometers, multiaperture X-ray cameras, and command box attitude control inflight by means of a television image radioed to ground. Spatial resolution ranged from five arc minutes to ten arc seconds and spectral resolution ranged from 500 to 3000. Several laboratory tasks were completed in order to achieve the desired resolution. These included (1) development of techniques to align grid collimators, (2) studies of the spectrometric properties of crystals, (3) measurements of the absorption coefficients of various materials used in X-ray spectrometers, (4) evaluation of the performance of multiaperture cameras, and (5) development of facilities.

  6. High-Resolution PET Detector. Final report

    SciTech Connect

    Karp, Joel

    2014-03-26

    The objective of this project was to develop an understanding of the limits of performance for a high resolution PET detector using an approach based on continuous scintillation crystals rather than pixelated crystals. The overall goal was to design a high-resolution detector, which requires both high spatial resolution and high sensitivity for 511 keV gammas. Continuous scintillation detectors (Anger cameras) have been used extensively for both single-photon and PET scanners, however, these instruments were based on NaI(Tl) scintillators using relatively large, individual photo-multipliers. In this project we investigated the potential of this type of detector technology to achieve higher spatial resolution through the use of improved scintillator materials and photo-sensors, and modification of the detector surface to optimize the light response function.We achieved an average spatial resolution of 3-mm for a 25-mm thick, LYSO continuous detector using a maximum likelihood position algorithm and shallow slots cut into the entrance surface.

  7. High Spatial Resolution Thermal Satellite Technologies

    NASA Technical Reports Server (NTRS)

    Ryan, Robert

    2003-01-01

    This document in the form of viewslides, reviews various low-cost alternatives to high spatial resolution thermal satellite technologies. There exists no follow-on to Landsat 7 or ASTER high spatial resolution thermal systems. This document reviews the results of the investigation in to the use of new technologies to create a low-cost useful alternative. Three suggested technologies are examined. 1. Conventional microbolometer pushbroom modes offers potential for low cost Landsat Data Continuity Mission (LDCM) thermal or ASTER capability with at least 60-120 ground sampling distance (GSD). 2. Backscanning could produce MultiSpectral Thermal Imager performance without cooled detectors. 3. Cooled detector could produce hyperspectral thermal class system or extremely high spatial resolution class instrument.

  8. A High Resolution Scale-of-four

    DOE R&D Accomplishments Database

    Fitch, V.

    1949-08-25

    A high resolution scale-of-four has been developed to be used in conjunction with the nuclear particle detection devices in applications where the counting rate is unusually high. Specifically, it is intended to precede the commercially available medium resolution scaling circuits and so decrease the resolving time of the counting system. The circuit will function reliably on continuously recurring pulses separated by less than 0.1 microseconds. It will resolve two pulses (occurring at a moderate repetition rate) which are spaced at 0.04 microseconds. A five-volt input signal is sufficient to actuate the device.

  9. RAPID DAMAGE ASSESSMENT FROM HIGH RESOLUTION IMAGERY

    SciTech Connect

    Vijayaraj, Veeraraghavan; Bright, Eddie A; Bhaduri, Budhendra L

    2008-01-01

    Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.

  10. Customized MFM probes with high lateral resolution.

    PubMed

    Iglesias-Freire, Óscar; Jaafar, Miriam; Berganza, Eider; Asenjo, Agustina

    2016-01-01

    Magnetic force microscopy (MFM) is a widely used technique for magnetic imaging. Besides its advantages such as the high spatial resolution and the easy use in the characterization of relevant applied materials, the main handicaps of the technique are the lack of control over the tip stray field and poor lateral resolution when working under standard conditions. In this work, we present a convenient route to prepare high-performance MFM probes with sub-10 nm (sub-25 nm) topographic (magnetic) lateral resolution by following an easy and quick low-cost approach. This allows one to not only customize the tip stray field, avoiding tip-induced changes in the sample magnetization, but also to optimize MFM imaging in vacuum (or liquid media) by choosing tips mounted on hard (or soft) cantilevers, a technology that is currently not available on the market. PMID:27547625

  11. Customized MFM probes with high lateral resolution

    PubMed Central

    Jaafar, Miriam; Berganza, Eider; Asenjo, Agustina

    2016-01-01

    Summary Magnetic force microscopy (MFM) is a widely used technique for magnetic imaging. Besides its advantages such as the high spatial resolution and the easy use in the characterization of relevant applied materials, the main handicaps of the technique are the lack of control over the tip stray field and poor lateral resolution when working under standard conditions. In this work, we present a convenient route to prepare high-performance MFM probes with sub-10 nm (sub-25 nm) topographic (magnetic) lateral resolution by following an easy and quick low-cost approach. This allows one to not only customize the tip stray field, avoiding tip-induced changes in the sample magnetization, but also to optimize MFM imaging in vacuum (or liquid media) by choosing tips mounted on hard (or soft) cantilevers, a technology that is currently not available on the market. PMID:27547625

  12. Customized MFM probes with high lateral resolution.

    PubMed

    Iglesias-Freire, Óscar; Jaafar, Miriam; Berganza, Eider; Asenjo, Agustina

    2016-01-01

    Magnetic force microscopy (MFM) is a widely used technique for magnetic imaging. Besides its advantages such as the high spatial resolution and the easy use in the characterization of relevant applied materials, the main handicaps of the technique are the lack of control over the tip stray field and poor lateral resolution when working under standard conditions. In this work, we present a convenient route to prepare high-performance MFM probes with sub-10 nm (sub-25 nm) topographic (magnetic) lateral resolution by following an easy and quick low-cost approach. This allows one to not only customize the tip stray field, avoiding tip-induced changes in the sample magnetization, but also to optimize MFM imaging in vacuum (or liquid media) by choosing tips mounted on hard (or soft) cantilevers, a technology that is currently not available on the market.

  13. Coregistration of high-resolution Mars orbital images

    NASA Astrophysics Data System (ADS)

    Sidiropoulos, Panagiotis; Muller, Jan-Peter

    2015-04-01

    The systematic orbital imaging of the Martian surface started 4 decades ago from NASA's Viking Orbiter 1 & 2 missions, which were launched in August 1975, and acquired orbital images of the planet between 1976 and 1980. The result of this reconnaissance was the first medium-resolution (i.e. ≤ 300m/pixel) global map of Mars, as well as a variety of high-resolution images (reaching up to 8m/pixel) of special regions of interest. Over the last two decades NASA has sent 3 more spacecraft with onboard instruments for high-resolution orbital imaging: Mars Global Surveyor (MGS) having onboard the Mars Orbital Camera - Narrow Angle (MOC-NA), Mars Odyssey having onboard the Thermal Emission Imaging System - Visual (THEMIS-VIS) and the Mars Reconnaissance Orbiter (MRO) having on board two distinct high-resolution cameras, Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE). Moreover, ESA has the multispectral High resolution Stereo Camera (HRSC) onboard ESA's Mars Express with resolution up to 12.5m since 2004. Overall, this set of cameras have acquired more than 400,000 high-resolution images, i.e. with resolution better than 100m and as fine as 25 cm/pixel. Notwithstanding the high spatial resolution of the available NASA orbital products, their accuracy of areo-referencing is often very poor. As a matter of fact, due to pointing inconsistencies, usually form errors in roll attitude, the acquired products may actually image areas tens of kilometers far away from the point that they are supposed to be looking at. On the other hand, since 2004, the ESA Mars Express has been acquiring stereo images through the High Resolution Stereo Camera (HRSC), with resolution that is usually 12.5-25 metres per pixel. The achieved coverage is more than 64% for images with resolution finer than 20 m/pixel, while for ~40% of Mars, Digital Terrain Models (DTMs) have been produced with are co-registered with MOLA [Gwinner et al., 2010]. The HRSC images and DTMs

  14. High resolution ultrasound and photoacoustic imaging of single cells

    PubMed Central

    Strohm, Eric M.; Moore, Michael J.; Kolios, Michael C.

    2016-01-01

    High resolution ultrasound and photoacoustic images of stained neutrophils, lymphocytes and monocytes from a blood smear were acquired using a combined acoustic/photoacoustic microscope. Photoacoustic images were created using a pulsed 532 nm laser that was coupled to a single mode fiber to produce output wavelengths from 532 nm to 620 nm via stimulated Raman scattering. The excitation wavelength was selected using optical filters and focused onto the sample using a 20× objective. A 1000 MHz transducer was co-aligned with the laser spot and used for ultrasound and photoacoustic images, enabling micrometer resolution with both modalities. The different cell types could be easily identified due to variations in contrast within the acoustic and photoacoustic images. This technique provides a new way of probing leukocyte structure with potential applications towards detecting cellular abnormalities and diseased cells at the single cell level. PMID:27114911

  15. High resolution ultrasound and photoacoustic imaging of single cells.

    PubMed

    Strohm, Eric M; Moore, Michael J; Kolios, Michael C

    2016-03-01

    High resolution ultrasound and photoacoustic images of stained neutrophils, lymphocytes and monocytes from a blood smear were acquired using a combined acoustic/photoacoustic microscope. Photoacoustic images were created using a pulsed 532 nm laser that was coupled to a single mode fiber to produce output wavelengths from 532 nm to 620 nm via stimulated Raman scattering. The excitation wavelength was selected using optical filters and focused onto the sample using a 20× objective. A 1000 MHz transducer was co-aligned with the laser spot and used for ultrasound and photoacoustic images, enabling micrometer resolution with both modalities. The different cell types could be easily identified due to variations in contrast within the acoustic and photoacoustic images. This technique provides a new way of probing leukocyte structure with potential applications towards detecting cellular abnormalities and diseased cells at the single cell level.

  16. Lift outs: how to acquire a high-functioning team.

    PubMed

    Groysberg, Boris; Abrahams, Robin

    2006-12-01

    More and more, expanding companies are hiring high-functioning groups of people who have been working together effectively within one company and can rapidly come up to speed in a new environment. These lifted-out teams don't need to get acquainted with one another or to establish shared values, mutual accountability, or group norms; their long-standing relationships and trust help them make an impact very quickly. Of course, the process is not without risks: A failed lift out can lead to loss of money, opportunity, credibility, and even native talent. Boris Groysberg and Robin Abrahams studied more than 40 high-profile moves and interviewed team leaders in multiple industries and countries to examine the risks and opportunities that lift outs present. They concluded that, regardless of industry, nationality, or size of the team, a successful lift out unfolds over four consecutive, interdependent stages that must be meticulously managed. In the courtship stage, the hiring company and the leader of the targeted team determine whether the proposed move is, in fact, a good idea, and then define their business goals and discuss strategies. At the same time, the team leader discusses the potential move with the other members of his or her group to assess their level of interest and prepare them for the change. The second stage involves the integration of the team leader with the new company's top leadership. This part of the process ensures the team's access to senior executives-the most important factor in a lift out's success. Operational integration is the focus of the third stage. Ideally, teams will start out working with the same or similar clients, vendors, and industry standards. The fourth stage entails full cultural integration. To succeed, the lifted-out team members must be willing to re-earn credibility by proving their value and winning their new colleagues' trust.

  17. Lift outs: how to acquire a high-functioning team.

    PubMed

    Groysberg, Boris; Abrahams, Robin

    2006-12-01

    More and more, expanding companies are hiring high-functioning groups of people who have been working together effectively within one company and can rapidly come up to speed in a new environment. These lifted-out teams don't need to get acquainted with one another or to establish shared values, mutual accountability, or group norms; their long-standing relationships and trust help them make an impact very quickly. Of course, the process is not without risks: A failed lift out can lead to loss of money, opportunity, credibility, and even native talent. Boris Groysberg and Robin Abrahams studied more than 40 high-profile moves and interviewed team leaders in multiple industries and countries to examine the risks and opportunities that lift outs present. They concluded that, regardless of industry, nationality, or size of the team, a successful lift out unfolds over four consecutive, interdependent stages that must be meticulously managed. In the courtship stage, the hiring company and the leader of the targeted team determine whether the proposed move is, in fact, a good idea, and then define their business goals and discuss strategies. At the same time, the team leader discusses the potential move with the other members of his or her group to assess their level of interest and prepare them for the change. The second stage involves the integration of the team leader with the new company's top leadership. This part of the process ensures the team's access to senior executives-the most important factor in a lift out's success. Operational integration is the focus of the third stage. Ideally, teams will start out working with the same or similar clients, vendors, and industry standards. The fourth stage entails full cultural integration. To succeed, the lifted-out team members must be willing to re-earn credibility by proving their value and winning their new colleagues' trust. PMID:17183798

  18. A High-Resolution Stopwatch for Cents

    ERIC Educational Resources Information Center

    Gingl, Z.; Kopasz, K.

    2011-01-01

    A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of a sound card. Dedicated free open-source software has been developed and made available to download. The efficiency is demonstrated by a free…

  19. High-resolution two dimensional advective transport

    USGS Publications Warehouse

    Smith, P.E.; Larock, B.E.

    1989-01-01

    The paper describes a two-dimensional high-resolution scheme for advective transport that is based on a Eulerian-Lagrangian method with a flux limiter. The scheme is applied to the problem of pure-advection of a rotated Gaussian hill and shown to preserve the monotonicity property of the governing conservation law.

  20. High resolution 3D fluorescence tomography using ballistic photons

    NASA Astrophysics Data System (ADS)

    Zheng, Jie; Nouizi, Farouk; Cho, Jaedu; Kwong, Jessica; Gulsen, Gultekin

    2015-03-01

    We are developing a ballistic-photon based approach for improving the spatial resolution of fluorescence tomography using time-domain measurements. This approach uses early photon information contained in measured time-of-fight distributions originating from fluorescence emission. The time point spread functions (TPSF) from both excitation light and emission light are acquired with gated single photon Avalanche detector (SPAD) and time-correlated single photon counting after a short laser pulse. To determine the ballistic photons for reconstruction, the lifetime of the fluorophore and the time gate from the excitation profiles will be used for calibration, and then the time gate of the fluorescence profile can be defined by a simple time convolution. By mimicking first generation CT data acquisition, the sourcedetector pair will translate across and also rotate around the subject. The measurement from each source-detector position will be reshaped into a histogram that can be used by a simple back-projection algorithm in order to reconstruct high resolution fluorescence images. Finally, from these 2D sectioning slides, a 3D inclusion can be reconstructed accurately. To validate the approach, simulation of light transport is performed for biological tissue-like media with embedded fluorescent inclusion by solving the diffusion equation with Finite Element Method using COMSOL Multiphysics simulation. The reconstruction results from simulation studies have confirmed that this approach drastically improves the spatial resolution of fluorescence tomography. Moreover, all the results have shown the feasibility of this technique for high resolution small animal imaging up to several centimeters.

  1. High resolution multiplexed functional imaging in live embyros (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Xu, Dongli; Peng, Leilei

    2016-03-01

    Optical projection tomography (OPT) creates isotropic 3D imaging of tissue. Two approaches exist today: Wide-field OPT illuminates the entire sample and acquires projection images with a camera; Scanning-laser optical tomography (SLOT) generates the projection with a moving laser beam and point detector. SLOT has superior light collecting efficiency than wide-field optical tomography, making it ideal for tissue fluorescence imaging. Regardless the approach, traditional OPT has to compromise between the resolution and the depth of view. In traditional SLOT, the focused Gaussian beam diverges quickly from the focused plane, making it impossible to achieve high resolution imaging through a large volume specimen. We report using Bessel beam instead of Gaussian beam to perform SLOT. By illuminating samples with a narrow Bessel beam throughout an extended depth, high-resolution projection images can be measured in large volume. Under Bessel illumination, the projection image contains signal from annular-rings of the Bessel beam. Traditional inverse Radon transform of these projections will result in ringing artifacts in reconstructed imaging. Thus a modified 3D filtered back projection algorithm is developed to perform tomography reconstructing of Bessel-illuminated projection images. The resulting 3D imaging is free of artifact and achieved cellular resolution in extended sample volume. The system is applied to in-vivo imaging of transgenic Zebrafish embryos. Results prove Bessel SLOT a promising imaging method in development biology research.

  2. High-Resolution Light Field Capture With Coded Aperture.

    PubMed

    Wang, Yu-Ping; Wang, Li-Chun; Kong, De-Hui; Yin, Bao-Cai

    2015-12-01

    Acquiring light field with larger angular resolution and higher spatial resolution in low cost is the goal of light field capture. Combining or modifying traditional optical cameras is a usual method for designing light field capture equipment, among which most models should deliberate trade-off between angular and spatial resolution, but augmenting coded aperture avoids this consideration by multiplexing information from different views. On the basis of coded aperture, this paper suggests an improved light field camera model that has double measurements and one mask. The two compressive measurements are respectively realized by a coded aperture and a random convolution CMOS imager, the latter is used as imaging sensor of the camera. The single mask design permits high light efficiency, which enables the sampling images to have high clarity. The double measurement design keeps more correlation information, which is conductive to enhancing the reconstructed light field. The higher clarity and more correlation of samplings mean higher quality of rebuilt light field, which also means higher resolution under condition of a lower PSNR requirement for rebuilt light field. Experimental results have verified advantage of the proposed design: compared with the representative mask-based light field camera models, the proposed model has the highest reconstruction quality and a higher light efficiency.

  3. High-Resolution, Two-Wavelength Pyrometer

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.; Henry, Paul K.; Logiurato, D. Daniel

    1989-01-01

    Modified two-color pyrometer measures temperatures of objects with high spatial resolution. Image focused on hole 0.002 in. (0.05 mm) in diameter in brass sheet near end of bundle, causing image to be distributed so fibers covered by defocused radiation from target. Pinhole ensures radiation from only small part of target scene reaches detector, thus providing required spatial resolution. By spreading radiation over bundle, pinhole ensures entire active area of detectors utilized. Produces signal as quiet as conventional instruments but with only 1/64 input radiation.

  4. A Portable, High Resolution, Surface Measurement Device

    NASA Technical Reports Server (NTRS)

    Ihlefeld, Curtis M.; Burns, Bradley M.; Youngquist, Robert C.

    2012-01-01

    A high resolution, portable, surface measurement device has been demonstrated to provide micron-resolution topographical plots. This device was specifically developed to allow in-situ measurements of defects on the Space Shuttle Orbiter windows, but is versatile enough to be used on a wide variety of surfaces. This paper discusses the choice of an optical sensor and then the decisions required to convert a lab bench optical measurement device into an ergonomic portable system. The necessary trade-offs between performance and portability are presented along with a description of the device developed to measure Orbiter window defects.

  5. Low-dose high-resolution CT of lung parenchyma

    SciTech Connect

    Zwirewich, C.V.; Mayo, J.R.; Mueller, N.L. )

    1991-08-01

    To evaluate the efficacy of low-dose high-resolution computed tomography (HRCT) in the assessment of lung parenchyma, three observers reviewed the scans of 31 patients. The 1.5-mm-collimation, 2-second, 120-kVp scans were obtained at 20 and 200 mA at selected identical levels in the chest. The observers evaluated the visualization of normal pulmonary anatomy, various parenchymal abnormalities and their distribution, and artifacts. The low-dose and conventional scans were equivalent in the evaluation of vessels, lobar and segmental bronchi, and anatomy of secondary pulmonary lobules, and in characterizing the extent and distribution of reticulation, honeycomb cysts, and thickened interlobular septa. The low-dose technique failed to demonstrate ground-glass opacity in two of 10 cases (20%) and emphysema in one of nine cases (11%), in which they were evident but subtle on the high-dose scans. These differences were not statistically significant. Linear streak artifact was more prominent on images acquired with the low-dose technique, but the two techniques were judged equally diagnostic in 97% of cases. The authors conclude that HRCT images acquired at 20 mA yield anatomic information equivalent to that obtained with 200-mA scans in the majority of patients, without significant loss of spatial resolution or image degradation due to linear streak artifact.

  6. High-resolution reconstruction for terahertz imaging.

    PubMed

    Xu, Li-Min; Fan, Wen-Hui; Liu, Jia

    2014-11-20

    We present a high-resolution (HR) reconstruction model and algorithms for terahertz imaging, taking advantage of super-resolution methodology and algorithms. The algorithms used include projection onto a convex sets approach, iterative backprojection approach, Lucy-Richardson iteration, and 2D wavelet decomposition reconstruction. Using the first two HR reconstruction methods, we successfully obtain HR terahertz images with improved definition and lower noise from four low-resolution (LR) 22×24 terahertz images taken from our homemade THz-TDS system at the same experimental conditions with 1.0 mm pixel. Using the last two HR reconstruction methods, we transform one relatively LR terahertz image to a HR terahertz image with decreased noise. This indicates potential application of HR reconstruction methods in terahertz imaging with pulsed and continuous wave terahertz sources.

  7. HIRIS - The High Resolution Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff

    1988-01-01

    The High-Resolution Imaging Spectrometer (HIRIS) is a JPL facility instrument designed for NASA's Earth Observing System (Eos).It will have 10-nm wide spectral bands from 0.4-2.5 microns at 30 m spatial resolution over a 30 km swath. The spectral resolution allows identification of many minerals in rocks and soils, important algal pigments in oceans and inland waters, spectral changes associated with plant canopy biochemistry, composition of atmospheric aerosols, and grain size of snow and its contamination by absorbing impurities. The bands wil have 12-bit quantization over a dynamic range suitable for bright targets, such as snow. For targets of low brightness, such as water bodies, image-motion compensation will allow gains up to a factor of eight to increase signal-to-noise ratios. In the 824-km orbit altitude proposed for Eos, the crosstrack pointing capability will allow 4-5 views during a 16-day revisit cycle.

  8. Constructing a WISE High Resolution Galaxy Atlas

    NASA Astrophysics Data System (ADS)

    Jarrett, T. H.; Masci, F.; Tsai, C. W.; Petty, S.; Cluver, M.; Assef, Roberto J.; Benford, D.; Blain, A.; Bridge, C.; Donoso, E.; Eisenhardt, P.; Fowler, J.; Koribalski, B.; Lake, S.; Neill, James D.; Seibert, M.; Sheth, K.; Stanford, S.; Wright, E.

    2012-08-01

    After eight months of continuous observations, the Wide-field Infrared Survey Explorer (WISE) mapped the entire sky at 3.4 μm, 4.6 μm, 12 μm, and 22 μm. We have begun a dedicated WISE High Resolution Galaxy Atlas project to fully characterize large, nearby galaxies and produce a legacy image atlas and source catalog. Here we summarize the deconvolution techniques used to significantly improve the spatial resolution of WISE imaging, specifically designed to study the internal anatomy of nearby galaxies. As a case study, we present results for the galaxy NGC 1566, comparing the WISE enhanced-resolution image processing to that of Spitzer, Galaxy Evolution Explorer, and ground-based imaging. This is the first paper in a two-part series; results for a larger sample of nearby galaxies are presented in the second paper.

  9. Constructing a WISE High Resolution Galaxy Atlas

    NASA Technical Reports Server (NTRS)

    Jarrett, T. H.; Masci, F.; Tsai, C. W.; Petty, S.; Cluver, M.; Assef, Roberto J.; Benford, D.; Blain, A.; Bridge, C.; Donoso, E.; Eisenhardt, P.; Fowler, J.; Koribalski, B.; Lake, S.; Neill, James D.; Seibert, M.; Stanford, S.; Wright, E.

    2012-01-01

    After eight months of continuous observations, the Wide-field Infrared Survey Explorer (WISE) mapped the entire sky at 3.4 micron, 4.6 micron, 12 micron, and 22 micron. We have begun a dedicated WISE High Resolution Galaxy Atlas project to fully characterize large, nearby galaxies and produce a legacy image atlas and source catalog. Here we summarize the deconvolution techniques used to significantly improve the spatial resolution of WISE imaging, specifically designed to study the internal anatomy of nearby galaxies. As a case study, we present results for the galaxy NGC 1566, comparing the WISE enhanced-resolution image processing to that of Spitzer, Galaxy Evolution Explorer, and ground-based imaging. This is the first paper in a two-part series; results for a larger sample of nearby galaxies are presented in the second paper.

  10. High-Resolution Traction Force Microscopy

    PubMed Central

    Plotnikov, Sergey V.; Sabass, Benedikt; Schwarz, Ulrich S.; Waterman, Clare M.

    2015-01-01

    Cellular forces generated by the actomyosin cytoskeleton and transmitted to the extracellular matrix (ECM) through discrete, integrin-based protein assemblies, that is, focal adhesions, are critical to developmental morphogenesis and tissue homeostasis, as well as disease progression in cancer. However, quantitative mapping of these forces has been difficult since there has been no experimental technique to visualize nanonewton forces at submicrometer spatial resolution. Here, we provide detailed protocols for measuring cellular forces exerted on two-dimensional elastic substrates with a high-resolution traction force microscopy (TFM) method. We describe fabrication of polyacrylamide substrates labeled with multiple colors of fiducial markers, functionalization of the substrates with ECM proteins, setting up the experiment, and imaging procedures. In addition, we provide the theoretical background of traction reconstruction and experimental considerations important to design a high-resolution TFM experiment. We describe the implementation of a new algorithm for processing of images of fiducial markers that are taken below the surface of the substrate, which significantly improves data quality. We demonstrate the application of the algorithm and explain how to choose a regularization parameter for suppression of the measurement error. A brief discussion of different ways to visualize and analyze the results serves to illustrate possible uses of high-resolution TFM in biomedical research. PMID:24974038

  11. High resolution schemes for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Harten, A.

    1983-01-01

    A class of new explicit second order accurate finite difference schemes for the computation of weak solutions of hyperbolic conservation laws is presented. These highly nonlinear schemes are obtained by applying a nonoscillatory first order accurate scheme to an appropriately modified flux function. The so-derived second order accurate schemes achieve high resolution while preserving the robustness of the original nonoscillatory first order accurate scheme. Numerical experiments are presented to demonstrate the performance of these new schemes.

  12. High resolution 3D nonlinear integrated inversion

    NASA Astrophysics Data System (ADS)

    Li, Yong; Wang, Xuben; Li, Zhirong; Li, Qiong; Li, Zhengwen

    2009-06-01

    The high resolution 3D nonlinear integrated inversion method is based on nonlinear theory. Under layer control, the log data from several wells (or all wells) in the study area and seismic trace data adjacent to the wells are input to a network with multiple inputs and outputs and are integratedly trained to obtain an adaptive weight function of the entire study area. Integrated nonlinear mapping relationships are built and updated by the lateral and vertical geologic variations of the reservoirs. Therefore, the inversion process and its inversion results can be constrained and controlled and a stable seismic inversion section with high resolution with velocity inversion, impedance inversion, and density inversion sections, can be gained. Good geologic effects have been obtained in model computation tests and real data processing, which verified that this method has high precision, good practicality, and can be used for quantitative reservoir analysis.

  13. Superconducting High Resolution Fast-Neutron Spectrometers

    SciTech Connect

    Hau, Ionel Dragos

    2006-01-01

    Superconducting high resolution fast-neutron calorimetric spectrometers based on 6LiF and TiB{sub 2} absorbers have been developed. These novel cryogenic spectrometers measure the temperature rise produced in exothermal (n, α) reactions with fast neutrons in 6Li and 10B-loaded materials with heat capacity C operating at temperatures T close to 0.1 K. Temperature variations on the order of 0.5 mK are measured with a Mo/Cu thin film multilayer operated in the transition region between its superconducting and its normal state. The advantage of calorimetry for high resolution spectroscopy is due to the small phonon excitation energies kBT on the order of μeV that serve as signal carriers, resulting in an energy resolution ΔE ~ (kBT2C)1/2, which can be well below 10 keV. An energy resolution of 5.5 keV has been obtained with a Mo/Cu superconducting sensor and a TiB2 absorber using thermal neutrons from a 252Cf neutron source. This resolution is sufficient to observe the effect of recoil nuclei broadening in neutron spectra, which has been related to the lifetime of the first excited state in 7Li. Fast-neutron spectra obtained with a 6Li-enriched LiF absorber show an energy resolution of 16 keV FWHM, and a response in agreement with the 6Li(n, α)3H reaction cross section and Monte Carlo simulations for energies up to several MeV. The energy resolution of order of a few keV makes this novel instrument applicable to fast-neutron transmission spectroscopy based on the unique elemental signature provided by the neutron absorption and scattering resonances. The optimization of the energy resolution based on analytical and numerical models of the detector response is discussed in the context of these applications.

  14. High-resolution Ceres High Altitude Mapping Orbit atlas derived from Dawn Framing Camera images

    NASA Astrophysics Data System (ADS)

    Roatsch, Th.; Kersten, E.; Matz, K.-D.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2016-09-01

    The Dawn spacecraft Framing Camera (FC) acquired over 2400 clear filter images of Ceres with a resolution of about 140 m/pixel during the six cycles in the High Altitude Mapping Orbit (HAMO) phase between August 18 and October 21, 2015. We ortho-rectified the images from the first cycle and produced a global, high-resolution, controlled photomosaic of Ceres. This global mosaic is the basis for a high-resolution Ceres atlas that consists of 15 tiles mapped at a scale of 1:750,000. The nomenclature used in this atlas was proposed by the Dawn team and was approved by the International Astronomical Union (IAU). The full atlas is available to the public through the Dawn Geographical Information System (GIS) web page

  15. High-Resolution US of Rheumatologic Diseases.

    PubMed

    Taljanovic, Mihra S; Melville, David M; Gimber, Lana H; Scalcione, Luke R; Miller, Margaret D; Kwoh, C Kent; Klauser, Andrea S

    2015-01-01

    For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

  16. High-resolution flurescence spectroscopy in immunoanalysis

    SciTech Connect

    Grubor, Nenad M.

    2005-01-01

    The work presented in this dissertation combines highly sensitive and selective fluorescence line-narrowing spectroscopy (FLNS) detection with various modes of immunoanalytical techniques. It has been shown that FLNS is capable of directly probing molecules immunocomplexed with antibodies, eliminating analytical ambiguities that may arise from interferences that accompany traditional immunochemical techniques. Moreover, the utilization of highly cross-reactive antibodies for highly specific analyte determination has been demonstrated. Finally, they demonstrate the first example of the spectral resolution of diastereomeric analytes based on their interaction with a cross-reactive antibody.

  17. High-Resolution Broadband Spectral Interferometry

    SciTech Connect

    Erskine, D J; Edelstein, J

    2002-08-09

    We demonstrate solar spectra from a novel interferometric method for compact broadband high-resolution spectroscopy. The spectral interferometer (SI) is a hybrid instrument that uses a spectrometer to externally disperse the output of a fixed-delay interferometer. It also has been called an externally dispersed interferometer (EDI). The interferometer can be used with linear spectrometers for imaging spectroscopy or with echelle spectrometers for very broad-band coverage. EDI's heterodyning technique enhances the spectrometer's response to high spectral-density features, increasing the effective resolution by factors of several while retaining its bandwidth. The method is extremely robust to instrumental insults such as focal spot size or displacement. The EDI uses no moving parts, such as purely interferometric FTS spectrometers, and can cover a much wider simultaneous bandpass than other internally dispersed interferometers (e.g. HHS or SHS).

  18. High resolution image measurements of nuclear tracks

    NASA Technical Reports Server (NTRS)

    Shirk, E. K.; Price, P. B.

    1980-01-01

    The striking clarity and high contrast of the mouths of tracks etched in CR-39 plastic detectors allow automatic measurement of track parameters to be made with simple image-recognition equipment. Using a commercially available Vidicon camera system with a microprocessor-controlled digitizer, resolution for normally incident C-12 and N-14 ions at 32 MeV/amu equivalent to a 14sigma separation of adjacent charges was demonstrated.

  19. Obtaining high resolution XUV coronal images

    NASA Technical Reports Server (NTRS)

    Golub, L.; Spiller, E.

    1992-01-01

    Photographs obtained during three flights of an 11 inch diameter normal incident soft X-ray (wavelength 63.5 A) telescope are analyzed and the data are compared to the results expected from tests of the mirror surfaces. Multilayer coated X ray telescopes have the potential for 0.01 arcsec resolution, and there is optimism that such high quality mirrors can be built. Some of the factors which enter into the performance actually achieved in practice are as follows: quality of the mirror substrate, quality of the multilayer coating, and number of photons collected. Measurements of multilayer mirrors show that the actual performance achieved in the solar X-ray images demonstrates a reduction in the scattering compared to that calculated from the topography of the top surface of the multilayer. In the brief duration of a rocket flight, the resolution is also limited by counting statistics from the number of photons collected. At X-ray Ultraviolet (XUV) wavelengths from 171 to 335 A the photon flux should be greater than 10(exp 10) ph/sec, so that a resolution better than 0.1 arcsec might be achieved, if mirror quality does not provide a limit first. In a satellite, a large collecting area will be needed for the highest resolution.

  20. High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography

    DOEpatents

    Olivier, Scot S.; Werner, John S.; Zawadzki, Robert J.; Laut, Sophie P.; Jones, Steven M.

    2010-09-07

    This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

  1. Automated electrostatic probe device of high resolution and accuracy

    SciTech Connect

    Aleiferis, S.

    2014-12-15

    In this work, an automated apparatus for driving single electrostatic probes and acquiring the plasma-related data has been designed and fabricated. The voltage range of the present system is ±110 V with an adjustable voltage step as low as 3 mV. Voltage and current measurements are carried out with high resolution and high accuracy circuits, both based on 16 bit analog-to-digital converters. The code embedded in a micro-controller, schedules the operation of the device and transfers the experimental data to a personal computer. The modular design of the system makes possible its modification and thus increases its adaptability to different plasma setups. Finally, the reliable operation of the entire device is confirmed by tests in Electron Cyclotron Resonance plasma.

  2. Binary Cepheids From High-Angular Resolution

    NASA Astrophysics Data System (ADS)

    Gallenne, A.; Mérand, A.; Kervella, P.

    2015-12-01

    Optical interferometry is the only technique giving access to milli-arcsecond (mas) spatial resolution. This is a powerful and unique tool to detect the close orbiting companions of Cepheids, and offers an unique opportunity to make progress in resolving the Cepheid mass discrepancy. Our goal in studying binary Cepheids is to measure the astrometric position of the high-contrast companion, and then combine them with spectroscopic measurements to derive the orbital elements, distances, and dynamical masses. In the course of this program, we developed a new tool, CANDID, to search for high-contrast companions and set detection limits from interferometric observations

  3. Moderate resolution spectrophotometry of high redshift quasars

    NASA Technical Reports Server (NTRS)

    Schneider, Donald P.; Schmidt, Maarten; Gunn, James E.

    1991-01-01

    A uniform set of photometry and high signal-to-noise moderate resolution spectroscopy of 33 quasars with redshifts larger than 3.1 is presented. The sample consists of 17 newly discovered quasars (two with redshifts in excess of 4.4) and 16 sources drawn from the literature. The objects in this sample have r magnitudes between 17.4 and 21.4; their luminosities range from -28.8 to -24.9. Three of the 33 objects are broad absorption line quasars. A number of possible high redshift damped Ly-alpha systems were found.

  4. High Resolution Laser Spectroscopy of Rhenium Carbide

    NASA Astrophysics Data System (ADS)

    Adam, Allan G.; Hall, Ryan M.; Linton, Colan; Tokaryk, Dennis

    2014-06-01

    The first spectroscopic study of rhenium carbide, ReC, has been performed using both low and high resolution techniques to collect rotationally resolved electronic spectra from 420 to 500nm. Laser-induced fluorescence (LIF), and dispersed fluorescence (DF) techniques were employed. ReC was formed in our laser ablation molecular jet apparatus by ablating a rhenium target rod in the presence of 1% methane in helium. The low resolution spectrum identified four bands of an electronic system belonging to ReC, three of which have been studied so far. Extensive hyperfine structure composed of six hyperfine components was observed in the high resolution spectrum, as well as a clear distinction between the 187ReC and 185ReC isotopologues. The data seems consistent with a ^4Π - ^4Σ- transition, as was predicted before experimentation. Dispersed fluorescence spectra allowed us to determine the ground state vibrational frequency (ωe"=994.4 ± 0.3 wn), and to identify a low-lying electronically excited state at Te"=1118.4 ± 0.4 wn with a vibrational frequency of ωe"=984 ± 2 wn. Personal communication, F. Grein, University of New Brunswick

  5. Comparative Very-High-Resolution VUV Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lewis, B. R.; Gibson, S. T.; Baldwin, K. G. H.; Dooley, P. M.; Waring, K.

    Despite their importance to the photochemistry of the terrestrial atmosphere, and many experimental studies, previous characterization of the Schumann-Runge (SR) bands of O2, B3 Σ u- <- X3 Σ_g^- (v, 0) (1750-2050 Å) has been limited by poor experimental resolution. In addition, our understanding of the SR spectrum is incomplete, many rovibrational transitions in the perturbed region of the spectrum [B(v > 15)] remaining unassigned. We review new very-high-resolution measurements of the O2 photoabsorption cross section in the SR bands. Tunable, narrow-bandwidth background vacuum-ultraviolet (VUV) radiation for the measurements ( 7 × 105 resolving power) was generated by the two-photon-resonant difference-frequency four-wave mixing in Xe of excimer-pumped dye-laser radiation. With the aid of these cross-section measurements, rovibrational and line-shape analyses have led to new insights into the molecular structure and predissociation dynamics of O2. The current VUV laser-spectroscopic measurements are shown to compare favourably with results from two other very-high-resolution experimental techniques, namely laser-induced fluorescence spectroscopy and VUV Fourier-transform spectroscopy, the latter performed using a synchrotron source.

  6. High-resolution phylogenetic microbial community profiling

    PubMed Central

    Singer, Esther; Bushnell, Brian; Coleman-Derr, Devin; Bowman, Brett; Bowers, Robert M; Levy, Asaf; Gies, Esther A; Cheng, Jan-Fang; Copeland, Alex; Klenk, Hans-Peter; Hallam, Steven J; Hugenholtz, Philip; Tringe, Susannah G; Woyke, Tanja

    2016-01-01

    Over the past decade, high-throughput short-read 16S rRNA gene amplicon sequencing has eclipsed clone-dependent long-read Sanger sequencing for microbial community profiling. The transition to new technologies has provided more quantitative information at the expense of taxonomic resolution with implications for inferring metabolic traits in various ecosystems. We applied single-molecule real-time sequencing for microbial community profiling, generating full-length 16S rRNA gene sequences at high throughput, which we propose to name PhyloTags. We benchmarked and validated this approach using a defined microbial community. When further applied to samples from the water column of meromictic Sakinaw Lake, we show that while community structures at the phylum level are comparable between PhyloTags and Illumina V4 16S rRNA gene sequences (iTags), variance increases with community complexity at greater water depths. PhyloTags moreover allowed less ambiguous classification. Last, a platform-independent comparison of PhyloTags and in silico generated partial 16S rRNA gene sequences demonstrated significant differences in community structure and phylogenetic resolution across multiple taxonomic levels, including a severe underestimation in the abundance of specific microbial genera involved in nitrogen and methane cycling across the Lake's water column. Thus, PhyloTags provide a reliable adjunct or alternative to cost-effective iTags, enabling more accurate phylogenetic resolution of microbial communities and predictions on their metabolic potential. PMID:26859772

  7. A high resolution ultraviolet Shuttle glow spectrograph

    NASA Technical Reports Server (NTRS)

    Carruthers, George R.

    1993-01-01

    The High Resolution Shuttle Glow Spectrograph-B (HRSGS-B) is a small payload being developed by the Naval Research Laboratory. It is intended for study of shuttle surface glow in the 180-400 nm near- and middle-ultraviolet wavelength range, with a spectral resolution of 0.2 nm. It will search for, among other possible features, the band systems of excited NO which result from surface-catalyzed combination of N and O. It may also detect O2 Hertzberg bands and N2 Vegard-Kaplan bands resulting from surface recombination. This wavelength range also includes possible N2+ and OH emissions. The HRSGS-B will be housed in a Get Away Special canister, mounted in the shuttle orbiter payload bay, and will observe the glow on the tail of the orbiter.

  8. Computer synthesis of high resolution electron micrographs

    NASA Technical Reports Server (NTRS)

    Nathan, R.

    1976-01-01

    Specimen damage, spherical aberration, low contrast and noisy sensors combine to prevent direct atomic viewing in a conventional electron microscope. The paper describes two methods for obtaining ultra-high resolution in biological specimens under the electron microscope. The first method assumes the physical limits of the electron objective lens and uses a series of dark field images of biological crystals to obtain direct information on the phases of the Fourier diffraction maxima; this information is used in an appropriate computer to synthesize a large aperture lens for a 1-A resolution. The second method assumes there is sufficient amplitude scatter from images recorded in focus which can be utilized with a sensitive densitometer and computer contrast stretching to yield fine structure image details. Cancer virus characterization is discussed as an illustrative example. Numerous photographs supplement the text.

  9. High-resolution adaptive spiking sonar.

    PubMed

    Alvarez, Fernando J; Kuc, Roman

    2009-05-01

    A new sonar system based on the conventional 6500 ranging module is presented that generates a sequence of spikes whose temporal density is related to the strength of the received echo. This system notably improves the resolution of a previous system by shortening the discharge cycle of the integrator included in the module. The operation is controlled by a PIC18F452 device, which can adapt the duration of the discharge to changing features of the echo, providing the system with a novel adaptive behavior. The performance of the new sensor is characterized and compared with that of the previous system by performing rotational scans of simple objects with different reflecting strengths. Some applications are suggested that exploit the high resolution and adaptability of this sensor.

  10. High resolution hyperspectral imaging with a high throughput virtual slit

    NASA Astrophysics Data System (ADS)

    Gooding, Edward A.; Gunn, Thomas; Cenko, Andrew T.; Hajian, Arsen R.

    2016-05-01

    Hyperspectral imaging (HSI) device users often require both high spectral resolution, on the order of 1 nm, and high light-gathering power. A wide entrance slit assures reasonable étendue but degrades spectral resolution. Spectrometers built using High Throughput Virtual Slit™ (HTVS) technology optimize both parameters simultaneously. Two remote sensing use cases that require high spectral resolution are discussed. First, detection of atmospheric gases with intrinsically narrow absorption lines, such as hydrocarbon vapors or combustion exhaust gases such as NOx and CO2. Detecting exhaust gas species with high precision has become increasingly important in the light of recent events in the automobile industry. Second, distinguishing reflected daylight from emission spectra in the visible and NIR (VNIR) regions is most easily accomplished using the Fraunhofer absorption lines in solar spectra. While ground reflectance spectral features in the VNIR are generally quite broad, the Fraunhofer lines are narrow and provide a signature of intrinsic vs. extrinsic illumination. The High Throughput Virtual Slit enables higher spectral resolution than is achievable with conventional spectrometers by manipulating the beam profile in pupil space. By reshaping the instrument pupil with reflective optics, HTVS-equipped instruments create a tall, narrow image profile at the exit focal plane, typically delivering 5X or better the spectral resolution achievable with a conventional design.

  11. High Spectral Resolution Lidar: System Calibration

    NASA Astrophysics Data System (ADS)

    Vivek Vivekanandan, J.; Morley, Bruce; Spuler, Scott; Eloranta, Edwin

    2015-04-01

    One of the unique features of the high spectral resolution lidar (HSRL) is simultaneous measurements of backscatter and extinction of atmosphere. It separates molecular scattering from aerosol and cloud particle backscatter based on their Doppler spectrum width. Scattering from aerosol and cloud particle are referred as Mie scattering. Molecular or Rayleigh scattering is used as a reference for estimating aerosol extinction and backscatter cross-section. Absolute accuracy of the backscattered signals and their separation into Rayleigh and Mie scattering depends on spectral purity of the transmitted signals, accurate measurement of transmit power, and precise performance of filters. Internal calibration is used to characterize optical subsystems Descriptions of high spectral resolution lidar system and its measurement technique can be found in Eloronta (2005) and Hair et al.(2001). Four photon counting detectors are used to measure the backscatter from the combined Rayleigh and molecular scattering (high and low gain), molecular scattering and cross-polarized signal. All of the detectors are sensitive to crosstalk or leakage through the optical filters used to separate the received signals and special data files are used to remove these effects as much as possible. Received signals are normalized with respect to the combined channel response to Mie and Rayleigh scattering. The laser transmit frequency is continually monitored and tuned to the 1109 Iodine absorption line. Aerosol backscatter cross-section is measured by referencing the aerosol return signal to the molecular return signal. Extinction measurements are calculated based on the differences between the expected (theoretical) and actual change in the molecular return. In this paper an overview of calibration of the HSRL is presented. References: Eloranta, E. W., High Spectral Resolution Lidar in Lidar: Range-Resolved Optical Remote Sensing of the Atmosphere, Klaus Weitkamp editor, Springer Series in Optical

  12. Computational analysis of high resolution unsteady airloads for rotor aeroacoustics

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; Lam, C.-M. Gordon; Wachspress, Daniel A.; Bliss, Donald B.

    1994-01-01

    The study of helicopter aerodynamic loading for acoustics applications requires the application of efficient yet accurate simulations of the velocity field induced by the rotor's vortex wake. This report summarizes work to date on the development of such an analysis, which builds on the Constant Vorticity Contour (CVC) free wake model, previously implemented for the study of vibratory loading in the RotorCRAFT computer code. The present effort has focused on implementation of an airload reconstruction approach that computes high resolution airload solutions of rotor/rotor-wake interactions required for acoustics computations. Supplementary efforts on the development of improved vortex core modeling, unsteady aerodynamic effects, higher spatial resolution of rotor loading, and fast vortex wake implementations have substantially enhanced the capabilities of the resulting software, denoted RotorCRAFT/AA (AeroAcoustics). Results of validation calculations using recently acquired model rotor data show that by employing airload reconstruction it is possible to apply the CVC wake analysis with temporal and spatial resolution suitable for acoustics applications while reducing the computation time required by one to two orders of magnitude relative to that required by direct calculations. Promising correlation with this body of airload and noise data has been obtained for a variety of rotor configurations and operating conditions.

  13. High-resolution phylogenetic microbial community profiling

    SciTech Connect

    Singer, Esther; Coleman-Derr, Devin; Bowman, Brett; Schwientek, Patrick; Clum, Alicia; Copeland, Alex; Ciobanu, Doina; Cheng, Jan-Fang; Gies, Esther; Hallam, Steve; Tringe, Susannah; Woyke, Tanja

    2014-03-17

    The representation of bacterial and archaeal genome sequences is strongly biased towards cultivated organisms, which belong to merely four phylogenetic groups. Functional information and inter-phylum level relationships are still largely underexplored for candidate phyla, which are often referred to as microbial dark matter. Furthermore, a large portion of the 16S rRNA gene records in the GenBank database are labeled as environmental samples and unclassified, which is in part due to low read accuracy, potential chimeric sequences produced during PCR amplifications and the low resolution of short amplicons. In order to improve the phylogenetic classification of novel species and advance our knowledge of the ecosystem function of uncultivated microorganisms, high-throughput full length 16S rRNA gene sequencing methodologies with reduced biases are needed. We evaluated the performance of PacBio single-molecule real-time (SMRT) sequencing in high-resolution phylogenetic microbial community profiling. For this purpose, we compared PacBio and Illumina metagenomic shotgun and 16S rRNA gene sequencing of a mock community as well as of an environmental sample from Sakinaw Lake, British Columbia. Sakinaw Lake is known to contain a large age of microbial species from candidate phyla. Sequencing results show that community structure based on PacBio shotgun and 16S rRNA gene sequences is highly similar in both the mock and the environmental communities. Resolution power and community representation accuracy from SMRT sequencing data appeared to be independent of GC content of microbial genomes and was higher when compared to Illumina-based metagenome shotgun and 16S rRNA gene (iTag) sequences, e.g. full-length sequencing resolved all 23 OTUs in the mock community, while iTags did not resolve closely related species. SMRT sequencing hence offers various potential benefits when characterizing uncharted microbial communities.

  14. High resolution millimeter-wave imaging sensor

    NASA Technical Reports Server (NTRS)

    Wilson, W. J.; Howard, R. J.; Parks, G. S.

    1985-01-01

    A scanning 3-mm radiometer is described that has been built for use on a small aircraft to produce real time high resolution images of the ground when atmospheric conditions such as smoke, dust, and clouds make IR and visual sensors unusable. The sensor can be used for a variety of remote sensing applications such as measurements of snow cover and snow water equivalent, precipitation mapping, vegetation type and extent, surface moisture and temperature, and surface thermal inertia. The advantages of millimeter waves for cloud penetration and the ability to observe different physical phenomena make this system an attractive supplement to visible and IR remote sensing systems.

  15. High resolution extremity CT for biomechanics modeling

    SciTech Connect

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-09-23

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling.

  16. High Resolution Image From Viking Lander 1

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Viking 1 took this high-resolution picture today, its third day on Mars. Distance from the camera to the nearfield (bottom) is about 4 meters (13 feet); to the horizon, about 3 kilometers (1.8 miles). The photo shows numerous angular blocks ranging in size from a few centimeters to several meters. The surface between the blocks is composed of fine-grained material. Accumulation of some fine-grained material behind blocks indicates wind deposition of dust and sand downwind of obstacles. The large block on the horizon is about 4 meters (13 feet) wide. Distance across the horizon is about 34 meters (110 feet).

  17. High Resolution Spectroscopy with Submillimeter-Wave

    NASA Astrophysics Data System (ADS)

    Kumar, Vinay; Dave, Hemant

    2003-03-01

    In order to explain the characteristic features of planetary atmosphere, detection and precise measurements of environmentally important gases such as CO, CIO, No becomes necessary. Since most of the polyatomic molecules have (ro-vibrational) transitions in submillimeter region 100 μ-1000μ), probing in this wavelength region is vital. The specific rotational and vibrational states are the result of interactions between different atoms in the molecule. Since each molecule has a unique arrangement of atoms, it has an exclusive submillimeter signature. We are developing a portable heterodyne receiver system at Physical Research Laboratory, Ahmedabad to perform high-resolution spectroscopy in this wavelength region.

  18. High-resolution stratigraphy with strontium isotopes.

    PubMed

    Depaolo, D J; Ingram, B L

    1985-02-22

    The isotopic ratio of strontium-87 to strontium-86 shows no detectable variation in present-day ocean water but changes slowly over millions of years. The strontium contained in carbonate shells of marine organisms records the ratio of strontium-87 to strontium-86 of the oceans at the time that the shells form. Sedimentary rocks composed of accumulated fossil carbonate shells can be dated and correlated with the use of high precision measurements of the ratio of strontium-87 to strontium-86 with a resolution that is similar to that of other techniques used in age correlation. This method may prove valuable for many geological, paleontological, paleooceanographic, and geochemical problems.

  19. High-Resolution Shadowing of Transfer RNA

    PubMed Central

    Abermann, Reinhard J.; Yoshikami, Doju

    1972-01-01

    High-resolution shadowing with metals that melt at high temperatures was used to study macromolecules. Molecules of transfer RNA shadowed with tantalum-tungsten are readily visualized in an electron microscope. Mounting procedures for tRNA were perfected that reproducibly gave uniform distributions of both monomeric and dimeric tRNA particles, and allowed a statistical assessment of their gross shapes and sizes. Monomeric tRNA yielded a fairly homogeneous population of rod-shaped particles, with axial dimensions of about 40 × 85 Å. Dimers of yeast alanine tRNA held together by hydrogen bonds and dimers constructed by covalent linkage of the amino-acid acceptor (3′-) termini of monomers both gave slightly more heterogeneous populations of particles. Yet, their structures were also basically rod shaped, with their lengths ranging to about twice that of the monomer; this result indicates an end-to-end arrangement of the monomeric units within both dimers. These results suggest that the amino-acid acceptor terminus and the anticodon region are at the ends of the rod-shaped, dehydrated tRNA monomer visible by electron microscopy, consistent with the generally accepted view of tRNA structure in solution suggested by other workers using other methods. This study demonstrates that high-resolution shadowing with tantalum-tungsten provides a means to examine the three-dimensional structures of relatively small biological macromolecules. Images PMID:4504373

  20. A super-resolution framework for 3-D high-resolution and high-contrast imaging using 2-D multislice MRI.

    PubMed

    Shilling, Richard Z; Robbie, Trevor Q; Bailloeul, Timothée; Mewes, Klaus; Mersereau, Russell M; Brummer, Marijn E

    2009-05-01

    A novel super-resolution reconstruction (SRR) framework in magnetic resonance imaging (MRI) is proposed. Its purpose is to produce images of both high resolution and high contrast desirable for image-guided minimally invasive brain surgery. The input data are multiple 2-D multislice inversion recovery MRI scans acquired at orientations with regular angular spacing rotated around a common frequency encoding axis. The output is a 3-D volume of isotropic high resolution. The inversion process resembles a localized projection reconstruction problem. Iterative algorithms for reconstruction are based on the projection onto convex sets (POCS) formalism. Results demonstrate resolution enhancement in simulated phantom studies, and ex vivo and in vivo human brain scans, carried out on clinical scanners. A comparison with previously published SRR methods shows favorable characteristics in the proposed approach.

  1. High resolution detection system of capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Wang, Li Qiang; Shi, Yan; Zheng, Hua; Lu, Zu Kang

    2007-12-01

    The capillary electrophoresis (CE) with laser induced fluorescence detection (LIFD) system was founded according to confocal theory. The 3-D adjustment of the exciting and collecting optical paths was realized. The photomultiplier tube (PMT) is used and the signals are processed by a software designed by ourselves. Under computer control, high voltage is applied to appropriate reservoirs and to inject and separate DNA samples respectively. Two fluorescent dyes Thiazole Orange (TO) and SYBR Green I were contrasted. With both of the dyes, high signals-to-noise images were obtained with the CE-LIFD system. The single-bases can be distinguished from the electrophoretogram and high resolution of DNA sample separation was obtained.

  2. A high-resolution Fourier Transform Spectrometer for planetary spectroscopy

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Sinton, W. M.

    1973-01-01

    The employment of a high-resolution Fourier Transform Spectrometer (FTS) is described for planetary and other astronomical spectroscopy in conjunction with the 88-inch telescope at Mauna Kea Observatory. The FTS system is designed for a broad range of uses, including double-beam laboratory spectroscopy, infrared gas chromatography, and nuclear magnetic resonance spectroscopy. The data system is well-suited to astronomical applications because of its great speed in acquiring and transforming data, and because of the enormous storage capability of the magnetic tape unit supplied with the system. The basic instrument is outlined 2nd some of the initial results from the first attempted use on the Mauna Kea 88-inch telescope are reported.

  3. High Resolution Quantitative Angle-Scanning Widefield Surface Plasmon Microscopy

    NASA Astrophysics Data System (ADS)

    Tan, Han-Min; Pechprasarn, Suejit; Zhang, Jing; Pitter, Mark C.; Somekh, Michael G.

    2016-02-01

    We describe the construction of a prismless widefield surface plasmon microscope; this has been applied to imaging of the interactions of protein and antibodies in aqueous media. The illumination angle of spatially incoherent diffuse laser illumination was controlled with an amplitude spatial light modulator placed in a conjugate back focal plane to allow dynamic control of the illumination angle. Quantitative surface plasmon microscopy images with high spatial resolution were acquired by post-processing a series of images obtained as a function of illumination angle. Experimental results are presented showing spatially and temporally resolved binding of a protein to a ligand. We also show theoretical results calculated by vector diffraction theory that accurately predict the response of the microscope on a spatially varying sample thus allowing proper quantification and interpretation of the experimental results.

  4. Crusta: Visualizing High-resolution Global Data

    NASA Astrophysics Data System (ADS)

    Bernardin, T. S.; Kreylos, O.; Bowles, C. J.; Cowgill, E.; Hamann, B.; Kellogg, L. H.

    2009-12-01

    Virtual globes have become indispensable tools for visualizing, understanding and presenting data from Earth and other planetary bodies. The scientific community has invested much effort into exploiting existing globes to their fullest potential by refining and adapting their capabilities to better satisfy specific needs. For example, Google Earth provides users with the ability to view hillshade images derived from airborne LiDAR data such as the 2007 Northern California GeoEarthScope data. However, because most available globes were not designed with the specific needs of geoscientists in mind, shortcomings are becoming increasingly evident in geoscience applications such as terrain visualization. In particular, earth scientists struggle to visualize digital elevation models with both high spatial resolution (0.5 - 1 square meters per sample) and large extent (>2000 square kilometers), such as those obtained with airborne LiDAR. To address the specific earth science need of real-time terrain visualization of LiDAR data, we are developing Crusta as part of a close collaboration involving earth and computer scientists. Crusta is a new virtual globe that differs from widely used globes by both providing accurate global data representation and the ability to easily visualize custom topographic and image data. As a result, Crusta enables real-time, interactive visualization of high resolution digital elevation data spanning thousands of square kilometers, such as the complete 2007 Northern California GeoEarthScope airborne LiDAR data set. To implement an accurate data representation and avoid distortion of the display at the poles, where other projections have singularities, Crusta represents the globe as a thirty-sided polyhedron. Each side of this polyhedron can be subdivided to an arbitrarily fine grid on the surface of the globe, which allows Crusta to accommodate input data of arbitrary resolution ranging from global (e.g., Blue Marble) to local (e.g., a tripod

  5. Low-cost camera modifications and methodologies for very-high-resolution digital images

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerial color and color-infrared photography are usually acquired at high altitude so the ground resolution of the photographs is < 1 m. Moreover, current color-infrared cameras and manned aircraft flight time are expensive, so the objective is the development of alternative methods for obtaining ve...

  6. Lysimetric evaluation of SEBAL using high resolution airborne imagery from BEAREX08

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, the SEBAL was evaluated for its ability to derive aerodynamic components and surface energy fluxes from high resolution airborne remote sensing data acquired during the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment 2008 in Texas, USA. Issues related to hot and...

  7. High Resolution Powder Diffraction and Structure Determination

    SciTech Connect

    Cox, D. E.

    1999-04-23

    It is clear that high-resolution synchrotrons X-ray powder diffraction is a very powerful and convenient tool for material characterization and structure determination. Most investigations to date have been carried out under ambient conditions and have focused on structure solution and refinement. The application of high-resolution techniques to increasingly complex structures will certainly represent an important part of future studies, and it has been seen how ab initio solution of structures with perhaps 100 atoms in the asymmetric unit is within the realms of possibility. However, the ease with which temperature-dependence measurements can be made combined with improvements in the technology of position-sensitive detectors will undoubtedly stimulate precise in situ structural studies of phase transitions and related phenomena. One challenge in this area will be to develop high-resolution techniques for ultra-high pressure investigations in diamond anvil cells. This will require highly focused beams and very precise collimation in front of the cell down to dimensions of 50 {micro}m or less. Anomalous scattering offers many interesting possibilities as well. As a means of enhancing scattering contrast it has applications not only to the determination of cation distribution in mixed systems such as the superconducting oxides discussed in Section 9.5.3, but also to the location of specific cations in partially occupied sites, such as the extra-framework positions in zeolites, for example. Another possible application is to provide phasing information for ab initio structure solution. Finally, the precise determination of f as a function of energy through an absorption edge can provide useful information about cation oxidation states, particularly in conjunction with XANES data. In contrast to many experiments at a synchrotron facility, powder diffraction is a relatively simple and user-friendly technique, and most of the procedures and software for data analysis

  8. Seamounts Identified By High-Resolution Imagery Offshore Kenya

    NASA Astrophysics Data System (ADS)

    Henderson, J. F.; Kagasi, J.; Gikuhi, M.; Njuguna, S.

    2008-12-01

    Multibeam bathymetry and 2-D seismic reflection surveys were carried out between 2007 and 2008 by the Government of Kenya for the purpose of delineating Kenya's extended continental shelf beyond the 200 nautical mile boundary, as allowed under Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS). The unique dataset acquired includes areas surveyed for the first time and provides new information on the geological processes of the continental shelf, slope and abyssal plain along the Kenyan passive margin. High-resolution multibeam bathymetry of almost the entire Kenyan continental slope was acquired using two multibeam systems (Kongsberg Simrad EM120 and EM710) aboard the M/V L'Espoir in November/December 2007. A multi-channel seismic survey followed in April/May 2008 (R/V Akademik Alexander Karpinsky) and provided high-resolution seismic reflection profiles. During these surveys, three features interpreted to be seamounts were discovered along Kenya's continental slope at water depths between 2750 and 3500 m. The size of the features varies from 2.5 to 10 km in diameter and 570 to 1740 m in height. The Davie Fracture Zone, a north-south trending transform fault was also identified in the seismic reflection profiles. The ridge, possibly extending from 26°S off south Madagascar to as far north as 2°S, is thought to have been created by the separation and direction of motion of Madagascar from Africa that began in the middle Jurassic. The discovery of these features and the integration of both multibeam bathymetry and seismic reflection profiles provides new information in the study of seamount distribution and their relationship to nearby transform faults.

  9. High resolution multimodal clinical ophthalmic imaging system.

    PubMed

    Mujat, Mircea; Ferguson, R Daniel; Patel, Ankit H; Iftimia, Nicusor; Lue, Niyom; Hammer, Daniel X

    2010-05-24

    We developed a multimodal adaptive optics (AO) retinal imager which is the first to combine high performance AO-corrected scanning laser ophthalmoscopy (SLO) and swept source Fourier domain optical coherence tomography (SSOCT) imaging modes in a single compact clinical prototype platform. Such systems are becoming ever more essential to vision research and are expected to prove their clinical value for diagnosis of retinal diseases, including glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinitis pigmentosa. The SSOCT channel operates at a wavelength of 1 microm for increased penetration and visualization of the choriocapillaris and choroid, sites of major disease activity for DR and wet AMD. This AO system is designed for use in clinical populations; a dual deformable mirror (DM) configuration allows simultaneous low- and high-order aberration correction over a large range of refractions and ocular media quality. The system also includes a wide field (33 deg.) line scanning ophthalmoscope (LSO) for initial screening, target identification, and global orientation, an integrated retinal tracker (RT) to stabilize the SLO, OCT, and LSO imaging fields in the presence of lateral eye motion, and a high-resolution LCD-based fixation target for presentation of visual cues. The system was tested in human subjects without retinal disease for performance optimization and validation. We were able to resolve and quantify cone photoreceptors across the macula to within approximately 0.5 deg (approximately 100-150 microm) of the fovea, image and delineate ten retinal layers, and penetrate to resolve features deep into the choroid. The prototype presented here is the first of a new class of powerful flexible imaging platforms that will provide clinicians and researchers with high-resolution, high performance adaptive optics imaging to help guide therapies, develop new drugs, and improve patient outcomes.

  10. High-Resolution Scintimammography: A Pilot Study

    SciTech Connect

    Rachel F. Brem; Joelle M. Schoonjans; Douglas A. Kieper; Stan Majewski; Steven Goodman; Cahid Civelek

    2002-07-01

    This study evaluated a novel high-resolution breast-specific gamma camera (HRBGC) for the detection of suggestive breast lesions. Methods: Fifty patients (with 58 breast lesions) for whom a scintimammogram was clinically indicated were prospectively evaluated with a general-purpose gamma camera and a novel HRBGC prototype. The results of conventional and high-resolution nuclear studies were prospectively classified as negative (normal or benign) or positive (suggestive or malignant) by 2 radiologists who were unaware of the mammographic and histologic results. All of the included lesions were confirmed by pathology. Results: There were 30 benign and 28 malignant lesions. The sensitivity for detection of breast cancer was 64.3% (18/28) with the conventional camera and 78.6% (22/28) with the HRBGC. The specificity with both systems was 93.3% (28/30). For the 18 nonpalpable lesions, sensitivity was 55.5% (10/18) and 72.2% (13/18) with the general-purpose camera and the HRBGC, respectively. For lesions 1 cm, 7 of 15 were detected with the general-purpose camera and 10 of 15 with the HRBGC. Four lesions (median size, 8.5 mm) were detected only with the HRBGC and were missed by the conventional camera. Conclusion: Evaluation of indeterminate breast lesions with an HRBGC results in improved sensitivity for the detection of cancer, with greater improvement shown for nonpalpable and 1-cm lesions.

  11. High Resolution Camera for Mapping Titan Surface

    NASA Technical Reports Server (NTRS)

    Reinhardt, Bianca

    2011-01-01

    Titan, Saturn's largest moon, has a dense atmosphere and is the only object besides Earth to have stable liquids at its surface. The Cassini/Huygens mission has revealed the extraordinary breadth of geological processes shaping its surface. Further study requires high resolution imaging of the surface, which is restrained by light absorption by methane and scattering from aerosols. The Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft has demonstrated that Titan's surface can be observed within several windows in the near infrared, allowing us to process several regions in order to create a geological map and to determine the morphology. Specular reflections monitored on the lakes of the North Pole show little scattering at 5 microns, which, combined with the present study of Titan's northern pole area, refutes the paradigm that only radar can achieve high resolution mapping of the surface. The present data allowed us to monitor the evolution of lakes, to identify additional lakes at the Northern Pole, to examine Titan's hypothesis of non-synchronous rotation and to analyze the albedo of the North Pole surface. Future missions to Titan could carry a camera with 5 micron detectors and a carbon fiber radiator for weight reduction.

  12. Common high-resolution MMW scene generator

    NASA Astrophysics Data System (ADS)

    Saylor, Annie V.; McPherson, Dwight A.; Satterfield, H. DeWayne; Sholes, William J.; Mobley, Scott B.

    2001-08-01

    The development of a modularized millimeter wave (MMW) target and background high resolution scene generator is reported. The scene generator's underlying algorithms are applicable to both digital and real-time hardware-in-the-loop (HWIL) simulations. The scene generator will be configurable for a variety of MMW and multi-mode sensors employing state of the art signal processing techniques. At present, digital simulations for MMW and multi-mode sensor development and testing are custom-designed by the seeker vendor and are verified, validated, and operated by both the vendor and government in simulation-based acquisition. A typical competition may involve several vendors, each requiring high resolution target and background models for proper exercise of seeker algorithms. There is a need and desire by both the government and sensor vendors to eliminate costly re-design and re-development of digital simulations. Additional efficiencies are realized by assuring commonality between digital and HWIL simulation MMW scene generators, eliminating duplication of verification and validation efforts.

  13. High-resolution light microscopy of nanoforms

    NASA Astrophysics Data System (ADS)

    Vodyanoy, Vitaly; Pustovyy, Oleg; Vainrub, Arnold

    2007-09-01

    We developed a high resolution light imaging system. Diffraction gratings with 100 nm width lines as well as less than 100 nm size features of different-shaped objects are clearly visible on a calibrated microscope test slide (Vainrub et al., Optics Letters, 2006, 31, 2855). The two-point resolution increase results from a known narrowing of the central diffraction peak for the annular aperture. Better visibility and advanced contrast of the smallest features in the image are due to enhancement of high spatial frequencies in the optical transfer function. The imaging system is portable, low energy, and battery operated. It has been adapted to use in both transmitting and reflecting light. It is particularly applicable for motile nanoform systems where structure and functions can be depicted in real time. We have isolated micrometer and submicrometer particles, termed proteons, from human and animal blood. Proteons form by reversible seeded aggregation of proteins around proteon nucleating centers (PNCs). PNCs are comprised of 1-2nm metallic nanoclusters containing 40-300 atoms. Proteons are capable of spontaneous assembling into higher nanoform systems assuming structure of complicated topology. The arrangement of complex proteon system mimics the structure of a small biological cell. It has structures that imitate membrane and nucleolus or nuclei. Some of these nanoforms are motile. They interact and divide. Complex nanoform systems can spontaneously reduce to simple proteons. The physical properties of these nanoforms could shed some light on the properties of early life forms or forms at extreme conditions.

  14. Limiting liability via high resolution image processing

    SciTech Connect

    Greenwade, L.E.; Overlin, T.K.

    1996-12-31

    The utilization of high resolution image processing allows forensic analysts and visualization scientists to assist detectives by enhancing field photographs, and by providing the tools and training to increase the quality and usability of field photos. Through the use of digitized photographs and computerized enhancement software, field evidence can be obtained and processed as `evidence ready`, even in poor lighting and shadowed conditions or darkened rooms. These images, which are most often unusable when taken with standard camera equipment, can be shot in the worst of photographic condition and be processed as usable evidence. Visualization scientists have taken the use of digital photographic image processing and moved the process of crime scene photos into the technology age. The use of high resolution technology will assist law enforcement in making better use of crime scene photography and positive identification of prints. Valuable court room and investigation time can be saved and better served by this accurate, performance based process. Inconclusive evidence does not lead to convictions. Enhancement of the photographic capability helps solve one major problem with crime scene photos, that if taken with standard equipment and without the benefit of enhancement software would be inconclusive, thus allowing guilty parties to be set free due to lack of evidence.

  15. High resolution wavefront measurement of aspheric optics

    NASA Astrophysics Data System (ADS)

    Erichsen, I.; Krey, S.; Heinisch, J.; Ruprecht, A.; Dumitrescu, E.

    2008-08-01

    With the recently emerged large volume production of miniature aspheric lenses for a wide range of applications, a new fast fully automatic high resolution wavefront measurement instrument has been developed. The Shack-Hartmann based system with reproducibility better than 0.05 waves is able to measure highly aspheric optics and allows for real time comparison with design data. Integrated advanced analysis tools such as calculation of Zernike coefficients, 2D-Modulation Transfer Function (MTF), Point Spread Function (PSF), Strehl-Ratio and the measurement of effective focal length (EFL) as well as flange focal length (FFL) allow for the direct verification of lens properties and can be used in a development as well as in a production environment.

  16. Low noise and high resolution microchannel plate

    NASA Astrophysics Data System (ADS)

    Liu, Shulin; Pan, Jingsheng; Deng, Guangxu; Su, Detan; Xu, Zhiqing; Zhang, Yanyun

    2008-02-01

    To improve the Figure of Merit (FOM) and reduce the Equivalent Background Input (EBI) and Fixed-Pattern-Noise (FPN) in image intensifier, NVT (North Night Vision Technology Co., Ltd) has been researching and developing a low noise and high resolution Micro Channel Plate (MCP). The density of dark current of this new MCP is less than 0.5PA/cm2 (when MCP voltage at 1000V). The FPN and scintillation noise are reduced remarkably. Channel diameter is 6 μm and open area ratio is 60%~70%. The vacuum bakeout temperature could be as high as 500°C. This new kind of MCP will be extensively used in the supper generation and the third generation image intensifiers.

  17. Evaluation of a high resolution silicon PET insert module

    NASA Astrophysics Data System (ADS)

    Grkovski, Milan; Brzezinski, Karol; Cindro, Vladimir; Clinthorne, Neal H.; Kagan, Harris; Lacasta, Carlos; Mikuž, Marko; Solaz, Carles; Studen, Andrej; Weilhammer, Peter; Žontar, Dejan

    2015-07-01

    Conventional PET systems can be augmented with additional detectors placed in close proximity of the region of interest. We developed a high resolution PET insert module to evaluate the added benefit of such a combination. The insert module consists of two back-to-back 1 mm thick silicon sensors, each segmented into 1040 1 mm2 pads arranged in a 40 by 26 array. A set of 16 VATAGP7.1 ASICs and a custom assembled data acquisition board were used to read out the signal from the insert module. Data were acquired in slice (2D) geometry with a Jaszczak phantom (rod diameters of 1.2-4.8 mm) filled with 18F-FDG and the images were reconstructed with ML-EM method. Both data with full and limited angular coverage from the insert module were considered and three types of coincidence events were combined. The ratio of high-resolution data that substantially improves quality of the reconstructed image for the region near the surface of the insert module was estimated to be about 4%. Results from our previous studies suggest that such ratio could be achieved at a moderate technological expense by using an equivalent of two insert modules (an effective sensor thickness of 4 mm).

  18. High-resolution colorimetric imaging of paintings

    NASA Astrophysics Data System (ADS)

    Martinez, Kirk; Cupitt, John; Saunders, David R.

    1993-05-01

    With the aim of providing a digital electronic replacement for conventional photography of paintings, a scanner has been constructed based on a 3000 X 2300 pel resolution camera which is moved precisely over a 1 meter square area. Successive patches are assembled to form a mosaic which covers the whole area at c. 20 pels/mm resolution, which is sufficient to resolve the surface textures, particularly craquelure. To provide high color accuracy, a set of seven broad-band interference filters are used to cover the visible spectrum. A calibration procedure based upon a least-mean-squares fit to the color of patches from a Macbeth Colorchecker chart yields an average color accuracy of better than 3 units in the CMC uniform color space. This work was mainly carried out as part of the VASARI project funded by the European Commission's ESPRIT program, involving companies and galleries from around Europe. The system is being used to record images for conservation research, for archival purposes and to assist in computer-aided learning in the field of art history. The paper will describe the overall system design, including the selection of the various hardware components and the design of controlling software. The theoretical basis for the color calibration methodology is described as well as the software for its practical implementation. The mosaic assembly procedure and some of the associated image processing routines developed are described. Preliminary results from the research will be presented.

  19. High resolution animated scenes from stills.

    PubMed

    Lin, Zhouchen; Wang, Lifeng; Wang, Yunbo; Kang, Sing Bing; Fang, Tian

    2007-01-01

    Current techniques for generating animated scenes involve either videos (whose resolution is limited) or a single image (which requires a significant amount of user interaction). In this paper, we describe a system that allows the user to quickly and easily produce a compelling-looking animation from a small collection of high resolution stills. Our system has two unique features. First, it applies an automatic partial temporal order recovery algorithm to the stills in order to approximate the original scene dynamics. The output sequence is subsequently extracted using a second-order Markov Chain model. Second, a region with large motion variation can be automatically decomposed into semiautonomous regions such that their temporal orderings are softly constrained. This is to ensure motion smoothness throughout the original region. The final animation is obtained by frame interpolation and feathering. Our system also provides a simple-to-use interface to help the user to fine-tune the motion of the animated scene. Using our system, an animated scene can be generated in minutes. We show results for a variety of scenes. PMID:17356221

  20. High-Resolution Radar Imagery of Mars

    NASA Astrophysics Data System (ADS)

    Harmon, John K.; Nolan, M. C.

    2009-09-01

    We present high-resolution radar images of Mars obtained during the 2005 and 2007 oppositions. The images were constructed from long-code delay-Doppler observations made with the Arecibo S-band (13-cm) radar. The average image resolution of 3 km represented a better than order-of-magnitude improvement over pre-upgrade Arecibo imagery of the planet. Images of depolarized reflectivity (an indicator primarily of wavelength-scale surface roughness) show the same bright volcanic flow features seen in earlier imagery, but with much finer detail. A new image of the Elysium region shows fine detail in the radar-bright channels of Athabasca Vallis, Marte Vallis, and Grjota Vallis. The new images of Tharsis and Olympus Mons also show a complex array of radar-bright and radar-dark features. Southern Amazonis exhibits some of the most complex and puzzling radar-bright structure on the planet. Another curiosity is the Chryse/Xanthe/Channels region, where we find some radar-bright features in or adjacent to fluvial chaos structures. Chryse/Xanthe is also the only region of Mars showing radar-bright craters (which are rare on Mars but common on the Moon and Mercury). We also obtained the first delay-Doppler image showing the enhanced backscatter from the residual south polar ice cap. In addition to the depolarized imagery, we were able to make the first delay-Doppler images of the circular polarization ratio (an important diagnostic for surface roughness texture). We find that vast areas of the radar-bright volcanic regions have polarization ratios close to unity. Such high ratios are rare for terrestrial lava flows and only seen for extremely blocky surfaces giving high levels of multiple scattering.

  1. Pyramidal fractal dimension for high resolution images.

    PubMed

    Mayrhofer-Reinhartshuber, Michael; Ahammer, Helmut

    2016-07-01

    Fractal analysis (FA) should be able to yield reliable and fast results for high-resolution digital images to be applicable in fields that require immediate outcomes. Triggered by an efficient implementation of FA for binary images, we present three new approaches for fractal dimension (D) estimation of images that utilize image pyramids, namely, the pyramid triangular prism, the pyramid gradient, and the pyramid differences method (PTPM, PGM, PDM). We evaluated the performance of the three new and five standard techniques when applied to images with sizes up to 8192 × 8192 pixels. By using artificial fractal images created by three different generator models as ground truth, we determined the scale ranges with minimum deviations between estimation and theory. All pyramidal methods (PM) resulted in reasonable D values for images of all generator models. Especially, for images with sizes ≥1024×1024 pixels, the PMs are superior to the investigated standard approaches in terms of accuracy and computation time. A measure for the possibility to differentiate images with different intrinsic D values did show not only that the PMs are well suited for all investigated image sizes, and preferable to standard methods especially for larger images, but also that results of standard D estimation techniques are strongly influenced by the image size. Fastest results were obtained with the PDM and PGM, followed by the PTPM. In terms of absolute D values best performing standard methods were magnitudes slower than the PMs. Concluding, the new PMs yield high quality results in short computation times and are therefore eligible methods for fast FA of high-resolution images.

  2. Pyramidal fractal dimension for high resolution images

    NASA Astrophysics Data System (ADS)

    Mayrhofer-Reinhartshuber, Michael; Ahammer, Helmut

    2016-07-01

    Fractal analysis (FA) should be able to yield reliable and fast results for high-resolution digital images to be applicable in fields that require immediate outcomes. Triggered by an efficient implementation of FA for binary images, we present three new approaches for fractal dimension (D) estimation of images that utilize image pyramids, namely, the pyramid triangular prism, the pyramid gradient, and the pyramid differences method (PTPM, PGM, PDM). We evaluated the performance of the three new and five standard techniques when applied to images with sizes up to 8192 × 8192 pixels. By using artificial fractal images created by three different generator models as ground truth, we determined the scale ranges with minimum deviations between estimation and theory. All pyramidal methods (PM) resulted in reasonable D values for images of all generator models. Especially, for images with sizes ≥1024 ×1024 pixels, the PMs are superior to the investigated standard approaches in terms of accuracy and computation time. A measure for the possibility to differentiate images with different intrinsic D values did show not only that the PMs are well suited for all investigated image sizes, and preferable to standard methods especially for larger images, but also that results of standard D estimation techniques are strongly influenced by the image size. Fastest results were obtained with the PDM and PGM, followed by the PTPM. In terms of absolute D values best performing standard methods were magnitudes slower than the PMs. Concluding, the new PMs yield high quality results in short computation times and are therefore eligible methods for fast FA of high-resolution images.

  3. Pyramidal fractal dimension for high resolution images.

    PubMed

    Mayrhofer-Reinhartshuber, Michael; Ahammer, Helmut

    2016-07-01

    Fractal analysis (FA) should be able to yield reliable and fast results for high-resolution digital images to be applicable in fields that require immediate outcomes. Triggered by an efficient implementation of FA for binary images, we present three new approaches for fractal dimension (D) estimation of images that utilize image pyramids, namely, the pyramid triangular prism, the pyramid gradient, and the pyramid differences method (PTPM, PGM, PDM). We evaluated the performance of the three new and five standard techniques when applied to images with sizes up to 8192 × 8192 pixels. By using artificial fractal images created by three different generator models as ground truth, we determined the scale ranges with minimum deviations between estimation and theory. All pyramidal methods (PM) resulted in reasonable D values for images of all generator models. Especially, for images with sizes ≥1024×1024 pixels, the PMs are superior to the investigated standard approaches in terms of accuracy and computation time. A measure for the possibility to differentiate images with different intrinsic D values did show not only that the PMs are well suited for all investigated image sizes, and preferable to standard methods especially for larger images, but also that results of standard D estimation techniques are strongly influenced by the image size. Fastest results were obtained with the PDM and PGM, followed by the PTPM. In terms of absolute D values best performing standard methods were magnitudes slower than the PMs. Concluding, the new PMs yield high quality results in short computation times and are therefore eligible methods for fast FA of high-resolution images. PMID:27475069

  4. Improved methods for high resolution electron microscopy

    SciTech Connect

    Taylor, J.R.

    1987-04-01

    Existing methods of making support films for high resolution transmission electron microscopy are investigated and novel methods are developed. Existing methods of fabricating fenestrated, metal reinforced specimen supports (microgrids) are evaluated for their potential to reduce beam induced movement of monolamellar crystals of C/sub 44/H/sub 90/ paraffin supported on thin carbon films. Improved methods of producing hydrophobic carbon films by vacuum evaporation, and improved methods of depositing well ordered monolamellar paraffin crystals on carbon films are developed. A novel technique for vacuum evaporation of metals is described which is used to reinforce microgrids. A technique is also developed to bond thin carbon films to microgrids with a polymer bonding agent. Unique biochemical methods are described to accomplish site specific covalent modification of membrane proteins. Protocols are given which covalently convert the carboxy terminus of papain cleaved bacteriorhodopsin to a free thiol. 53 refs., 19 figs., 1 tab.

  5. (Development of high spectral resolution lidar technology)

    SciTech Connect

    Eloranta, E.W.

    1991-07-30

    The first year of this grant has been devoted to the design and construction of an upgraded version of the University of Wisconsin High Spectral Resolution Lidar (HSRL). The new system incorporates additional data channels to measure depolarization and multiple scattering in the lidar return. Schematic diagrams describing the new configurations are attached to this report. Increases in optical efficiency and receiver aperture, coupled with improvements in the stiffness and the thermal stability of the mechanical system are expected to significantly improve the performance of the instrument. Most components of the system are nearly completed and system integration is about to begin. The HSRL is committed to participate in the NASA FIRE cirrus experiment during November and December of this year. Our progress is completing HSRL subsystems is outlined in the following paragraphs. 3 figs.

  6. Improved methods for high resolution electron microscopy

    NASA Astrophysics Data System (ADS)

    Taylor, J. R.

    1987-04-01

    Existing methods of making support films for high resolution transmission electron microscopy are investigated and novel methods are developed. Existing methods of fabricating fenestrated, metal reinforced specimen supports (microgrids) are evaluated for their potential to reduce beam induced movement of monolamellar crystals of C44H90 paraffin supported on thin carbon films. Improved methods of producing hydrophobic carbon films by vacuum evaporation, and improved methods of depositing well ordered monolamellar paraffin crystals on carbon films are developed. A novel technique for vacuum evaporation of metals is described which is used to reinforce microgrids. A technique is also developed to bond thin carbon films to microgrids with a polymer bonding agent. Unique biochemical methods are described to accomplish site specific covalent modification of membrane proteins. Protocols are given which covalently convert the carboxy terminus of papain cleaved bacteriorhodopsin to a free thiol.

  7. Potential High Resolution Dosimeters For MRT

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

    2010-07-01

    Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow (˜25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 μm microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron

  8. Potential High Resolution Dosimeters For MRT

    SciTech Connect

    Braeuer-Krisch, E.; Brochard, T.; Prezado, Y.; Bravin, A.; Berkvens, P.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Kamlowski, A.; Cellere, G.

    2010-07-23

    Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow ({approx}25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 {mu}m microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy

  9. High resolution analysis of satellite gradiometry

    NASA Technical Reports Server (NTRS)

    Colombo, O. L.

    1989-01-01

    Satellite gravity gradiometry is a technique now under development which, by the middle of the next decade, may be used for the high resolution charting from space of the gravity field of the earth and, afterwards, of other planets. Some data analysis schemes are reviewed for getting detailed gravity maps from gradiometry on both a global and a local basis. It also presents estimates of the likely accuracies of such maps, in terms of normalized spherical harmonics expansions, both using gradiometry alone and in combination with data from a Global Positioning System (GPS) receiver carried on the same spacecraft. It compares these accuracies with those of current and future maps obtained from other data (conventional tracking, satellite-satellite tracking, etc.), and also with the spectra of various signals of geophysical interest.

  10. High-resolution MRI: in vivo histology?

    PubMed Central

    Bridge, Holly; Clare, Stuart

    2005-01-01

    For centuries scientists have been fascinated with the question of how the brain works. Investigators have looked at both where different functions are localized and how the anatomical microstructure varies across the brain surface. Here we discuss how advances in magnetic resonance imaging (MRI) have allowed in vivo visualization of the fine structure of the brain that was previously only visible in post-mortem brains. We present data showing the correspondence between definitions of the primary visual cortex defined anatomically using very high-resolution MRI and functionally using functional MRI. We consider how this technology can be applied to allow the investigation of brains that differ from normal, and what this ever-evolving technology may be able to reveal about in vivo brain structure in the next few years. PMID:16553313

  11. Internal reflection sensors with high angular resolution

    NASA Astrophysics Data System (ADS)

    Shavirin, I.; Strelkov, O.; Vetskous, A.; Norton-Wayne, L.; Harwood, R.

    1996-07-01

    We discuss the use of total internal reflection for the production of sensors with high angular resolution. These sensors are intended for measurement of the angle between a sensor's axis and the direction to a source of radiation or reflecting object. Sensors of this type are used in controlling the position of machine parts in robotics and industry, orienting space vehicles and astronomic devices in relation to the Sun, and as autocollimators for checking angles of deviation. This kind of sensor was used in the Apollo space vehicle some 20 years ago. Using photodetectors with linear and area CCD arrays has opened up new application possibilities for appropriately designed sensors. A generalized methodology is presented applicable to a wide range of tasks. Some modifications that can improve the performance of the basic design are described.

  12. Limits of simulation based high resolution EBSD.

    PubMed

    Alkorta, Jon

    2013-08-01

    High resolution electron backscattered diffraction (HREBSD) is a novel technique for a relative determination of both orientation and stress state in crystals through digital image correlation techniques. Recent works have tried to use simulated EBSD patterns as reference patterns to achieve the absolute orientation and stress state of crystals. However, a precise calibration of the pattern centre location is needed to avoid the occurrence of phantom stresses. A careful analysis of the projective transformation involved in the formation of EBSD patterns has permitted to understand these phantom stresses. This geometrical analysis has been confirmed by numerical simulations. The results indicate that certain combinations of crystal strain states and sample locations (pattern centre locations) lead to virtually identical EBSD patterns. This ambiguity makes the problem of solving the absolute stress state of a crystal unfeasible in a single-detector configuration. PMID:23676453

  13. High-Resolution Anamorphic SPECT Imaging

    PubMed Central

    Durko, Heather L.; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    We have developed a gamma-ray imaging system that combines a high-resolution silicon detector with two sets of movable, half-keel-edged copper-tungsten blades configured as crossed slits. These apertures can be positioned independently between the object and detector, producing an anamorphic image in which the axial and transaxial magnifications are not constrained to be equal. The detector is a 60 mm × 60 mm, one-millimeter-thick, one-megapixel silicon double-sided strip detector with a strip pitch of 59 μm. The flexible nature of this system allows the application of adaptive imaging techniques. We present system details; calibration, acquisition, and reconstruction methods; and imaging results. PMID:26160983

  14. High resolution derivative spectra in remote sensing

    NASA Technical Reports Server (NTRS)

    Demetriades-Shah, Tanvir H.; Steven, Michael D.; Clark, Jeremy A.

    1990-01-01

    The use of derivative spectra is an established technique in analytical chemistry for the elimination of background signals and for resolving overlapping spectral features. Application of this technique for tackling analogous problems such as interference from soil background reflectance in the remote sensing of vegetation or for resolving complex spectra of several target species within individual pixels in remote sensing is proposed. Methods for generating derivatives of high spectral resolution data are reviewed. Results of experiments to test the use of derivatives for monitoring chlorosis in vegetation show that derivative spectral indices are superior to conventional broad-band spectral indices such as the near-infrared/red reflectance ratio. Conventional broad-band indices are sensitive to both leaf cover as well as leaf color. New derivative spectral indices which were able to monitor chlorosis unambiguously were identified. Potential areas for the application of this technique in remote sensing are considered.

  15. High Spatial Resolution Spectroscopy of Semiconductor Nanostructures

    NASA Astrophysics Data System (ADS)

    Harris, Timothy D.; Gershoni, David; Pfeiffer, Loren N.

    1996-03-01

    Several recent reports employing high spatial resolution have revealed the dominance of exciton localization in the low temperature luminescence of semiconductor quantum structures.^[1-3] Understanding this localization is of critical importance for the reliable studies of low dimensional structures such as quantum wells, quantum wires and quantum dots. We report on low temperature and high spatial resolution photoluminescence and photoluminescence excitation studies of cleaved edge overgrown (CEO) single quantum wires. These samples permit the direct and unambiguous comparison between the optical properties of a (100) oriented quantum well, a (110) oriented quantum well, and the quantum wire which is formed at their intersection. Using low temperature near field optical spectroscopy, and a novel diffraction limited far field apparatus, we determine the carrier diffusion length dependence on pump wavelength and sample temperature in both the 2d systems and the genuinely 1D wire system. We also measure the absorption strength of the 1D system and find it to be a factor of 3 stronger than the absorption of the associated 2D systems.^[2] Using low temperature near field optical spectroscopy, and a novel diffraction limited far field apparatus, we also determine the carrier diffusion length dependence on pump wavelength and sample temperature. ^[1] H. F. Hess, E. Betzig, T. D. Harris, L. N. Pfeiffer, and K. W. West, Science 264, 1740 (1994). ^[2] T. D. Harris, D. Gershoni, R. D. Grober, L. Pfeiffer, K. West, and N. Chand, Appl. Phys. Lett, in press (1996) ^[3] D. Gammon, E. S. Snow, and D. S. Katzer, Appl. Phys. Lett. 67, 2391 (1995)

  16. Ecological applications of high resolution spectrometry

    NASA Technical Reports Server (NTRS)

    Lawrence, William T.

    1989-01-01

    Future directions of NASA's space program plans include a significant effort at studying the Earth as a system of interrelated ecosystems. As part of NASA's Earth Observing System (Eos) Program a series of space platforms will be launched and operated to study the Earth with a variety of active and passive instruments. Several of the Eos instruments will be capable of imaging the planet's surface reflectance on a large number of very narrow portions of the solar spectrum. After the development of appropriate algorithms, this reflectance information will be used to determine key parameters about the structure and function of terrestrial and aquatic ecosystems and the pattern and processes of those systems across large areas of the globe. Algorithm development applicable to terrestrial systems will permit the inference of ecological processes from high resolution spectrometry data, similar to that to be forthcoming from the Eos mission. The first summer was spent working with tropical soils and relating their reflectance characteristics to particle size, iron content, and color. This summer the emphasis is on vegetation and work was begun with the Forest Ecosystems Dynamics Project in the Earth Resources Branch where both optical and radar characteristics of a mixed conifer/hardwood forest in Maine are being studied for use in a ecological modeling effort. A major series of aircraft overflights will take place throughout the summer. Laboratory and field spectrometers are used to measure the spectral reflectance of a hierarchy of vegetation from individual leaves to whole canopies for eventual modeling of their nutrient content using reflectance data. Key leaf/canopy parameters are being approximated including chlorophyll, nitrogen, phosphorus, water content, and leaf specific weight using high resolution spectrometry alone. Measurements are made of carbon exchange across the landscape for input to a spatial modeling effort to gauge production within the forest. A

  17. High Resolution Imaging of Satellites with Ground-Based 10-m Astronomical Telescopes

    SciTech Connect

    Marois, C

    2007-01-04

    High resolution imaging of artificial satellites can play an important role in current and future space endeavors. One such use is acquiring detailed images that can be used to identify or confirm damage and aid repair plans. It is shown that a 10-m astronomical telescope equipped with an adaptive optics system (AO) to correct for atmospheric turbulence using a natural guide star can acquire high resolution images of satellites in low-orbits using a fast shutter and a near-infrared camera even if the telescope is not capable of tracking satellites. With the telescope pointing towards the satellite projected orbit and less than 30 arcsec away from a guide star, multiple images of the satellite are acquired on the detector using the fast shutter. Images can then be shifted and coadded by post processing to increase the satellite signal to noise ratio. Using the Keck telescope typical Strehl ratio and anisoplanatism angle as well as a simple diffusion/reflection model for a satellite 400 km away observed near Zenith at sunset or sunrise, it is expected that such system will produced > 10{sigma} K-band images at a resolution of 10 cm inside a 60 arcsec diameter field of view. If implemented, such camera could deliver the highest resolution satellite images ever acquired from the ground.

  18. Rapid calibrated high-resolution hyperspectral imaging using tunable laser source

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam K.; Margalith, Eli

    2009-05-01

    We present a novel hyperspectral imaging technique based on tunable laser technology. By replacing the broadband source and tunable filters of a typical NIR imaging instrument, several advantages are realized, including: high spectral resolution, highly variable field-of-views, fast scan-rates, high signal-to-noise ratio, and the ability to use optical fiber for efficient and flexible sample illumination. With this technique, high-resolution, calibrated hyperspectral images over the NIR range can be acquired in seconds. The performance of system features will be demonstrated on two example applications: detecting melamine contamination in wheat gluten and separating bovine protein from wheat protein in cattle feed.

  19. Noninvasive mapping of subcutaneous vasculature with high resolution photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Lao, Yeqi; Xing, Da; Yang, Sihua

    2007-11-01

    As a novel hybrid imaging modality, photoacoustic (PA) imaging combines the merits of high optical contrast, good ultrasonic resolution and sufficient imaging depth, which may be of great benefit to noninvasively detect and monitor the pathological changes of subcutaneous vasculature, e.g., congenital vascular tumor and vascular malformation. In this paper, we apply a set of photoacoustic imaging system to image a sample of subcutaneous blood vessels, which is used to simulate the location of human's subcutaneous vasculature. Furthermore, an image of subcutaneous vasculature of the abdomen in a mouse is acquired in vivo. Laser pulses at a wavelength of 532 nm from a Q-switched Nd:YAG laser are employed as light source to generate PA signals in the experiments, because the optical absorption of whole blood is much stronger than that of other tissues at this wavelength. A needle polyvinylidene fluoride (PVDF) hydrophone with a diameter of 1mm is used to capture PA signals through a circular scan. The experimental results show that detailed structural information of subcutaneous vasculature, such as the shape and position of the blood vessels and the vessel branching, is clearly revealed by the PA imaging system. The spatial resolution of the PA imaging system reaches 80μm. Moreover, the reconstructed image of a mouse's abdomen in vivo demonstrates that this technique is suitable for noninvasive subcutaneous vasculature imaging. All of the results prove that the PA imaging can be used as a helpful tool for monitoring the pathological changes of subcutaneous vasculature.

  20. High Resolution Imaging Spectrometer (HIRIS): Science and Instrument

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Davis, Curtiss O.

    1991-01-01

    The High Resolution Imaging Spectrometer (HIRIS) is a facility instrument slated for flight on the second of the EOS-A series of platforms. HIRIS is designed to acquire 24-km wide, 30-m pixel images in 192 spectral bands simultaneously in the 0.4-2.45-micrometer wavelength region. With pointing mirrors it can sample any place on Earth, except the poles, every two days. HIRIS operates at the intermediate scale between the human and the global and therefore links studies of Earth surface processes to global monitoring carried out by lower-resolution instruments. So far, over 50 science data products from HIRIS images have been identified in the fields of atmospheric gases, clouds, snow and ice, water, vegetation, and rocks and soils. The key attribute of imaging spectrometry that makes it possible to derive quantitative information from the data is the large number of contiguous spectral bands. Therefore spectrum matching techniques can be applied. Such techniques are not possible with present-day, multispectral scanner data.

  1. Schiaparelli Crater Rim and Interior Deposits - High Resolution Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A portion of the rim and interior of the large impact crater Schiaparelli is seen at high resolution in this image acquired October 18, 1997 by the Mars Global Surveyor Orbiter Camera (MOC). The area covered is very small--3.9 X 10.2 km (2.4 X 6.33 mi)--but is seen at 63 times higher resolution than the Viking image. The subdued relief and bright surface are attributed to blanketing by dust; many small craters have been completely filled in, and only the most recent (and very small) craters appear sharp and bowl-shaped. Some of the small craters are only 10-12 m (30-35 feet) across. Occasional dark streaks on steeper slopes are small debris slides that have probably occurred in the past few decades. The two prominent, narrow ridges in the center of the image may be related to the adjustment of the crater floor to age or the weight of the material filling the basin.

    Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  2. High-Resolution Observations of a Binary Black Hole Candidate

    NASA Astrophysics Data System (ADS)

    Tsai, Chao-Wei; Phillips, Chris; Norris, Ray; Jarrett, Thomas; Emonts, Bjorn; Cluver, Michelle; Eisenhardt, Peter; Stern, Daniel; Assef, Roberto

    2012-10-01

    We propose a 12-hour 2.3 GHz continuum Long Baseline Array (LBA) observation of WISE J2332-5056, a newly discovered supermassive black hole (SMBH) merger candidate that is located in the nearby universe (z = 0.3447). Our recently acquired 9 GHz ATCA map shows unusual radio morphology: a one-sided, smaller (and likely younger) FR-I jet perpendicular to a larger, Doppler-boosted FR-II jet. Follow-up Gemini-S/GMOS spectroscopy of this WISE-selected radio galaxy reveals broad emission lines blue-shifted by > 3,500 km/s with respect to the narrow lines and host galaxy, hallmarks of a dual AGN system. Combined, the optical spectroscopy and radio morphology of this object are strongly suggestive of a black hole merger system. Even in the local universe these systems are extremely difficult to identify; yet the process of supermassive blackhole growth is vital toward understanding galaxy evolution from the early to the current universe. Moreover, nearby merging SMBHs may serve as outstanding targets for gravitational wave studies. The proposed high resolution LBA map, reaching 50 pc resolution at the source redshift will allow us to investigate the SMBH merger scenario hypothesis.

  3. The HFIP High Resolution Hurricane Forecast Test

    NASA Astrophysics Data System (ADS)

    Nance, L. B.; Bernardet, L.; Bao, S.; Brown, B.; Carson, L.; Fowler, T.; Halley Gotway, J.; Harrop, C.; Szoke, E.; Tollerud, E. I.; Wolff, J.; Yuan, H.

    2010-12-01

    Tropical cyclones are a serious concern for the nation, causing significant risk to life, property and economic vitality. The National Oceanic and Atmospheric Administration (NOAA) National Weather Service has a mission of issuing tropical cyclone forecasts and warnings, aimed at protecting life and property and enhancing the national economy. In the last 10 years, the errors in hurricane track forecasts have been reduced by about 50% through improved model guidance, enhanced observations, and forecaster expertise. However, little progress has been made during this period toward reducing forecasted intensity errors. To address this shortcoming, NOAA established the Hurricane Forecast Improvement Project (HFIP) in 2007. HFIP is a 10-year plan to improve one to five day tropical cyclone forecasts, with a focus on rapid intensity change. Recent research suggests that prediction models with grid spacing less than 1 km in the inner core of the hurricane may provide a substantial improvement in intensity forecasts. The 2008-09 staging of the High Resolution Hurricane (HRH) Test focused on quantifying the impact of increased horizontal resolution in numerical models on hurricane intensity forecasts. The primary goal of this test was an evaluation of the effect of increasing horizontal resolution within a given model across a variety of storms with different intensity, location and structure. The test focused on 69 retrospectives cases from the 2005 and 2007 hurricane seasons. Six modeling groups participated in the HRH test utilizing a variety of models, including three configurations of the Weather Research and Forecasting (WRF) model, the operational GFDL model, the Navy’s tropical cyclone model, and a model developed at the University of Wisconsin-Madison (UWM). The Development Testbed Center (DTC) was tasked with providing objective verification statistics for a variety of metrics. This presentation provides an overview of the HRH Test and a summary of the standard

  4. High resolution electron attachment to CO₂ clusters.

    PubMed

    Denifl, Stephan; Vizcaino, Violaine; Märk, Tilmann D; Illenberger, Eugen; Scheier, Paul

    2010-01-01

    Electron attachment to CO₂ clusters performed at high energy resolution (0.1 eV) is studied for the first time in the extended electron energy range from threshold (0 eV) to about 10 eV. Dissociative electron attachment (DEA) to single molecules yields O(-) as the only fragment ion arising from the well known (2)Π(u) shape resonance (ion yield centered at 4.4 eV) and a core excited resonance (at 8.2 eV). On proceeding to CO₂ clusters, non-dissociated complexes of the form (CO₂)(n)(-) including the monomer CO₂(-) are generated as well as solvated fragment ions of the form (CO₂)(n)O(-). The non-decomposed complexes appear already within a resonant feature near threshold (0 eV) and also within a broad contribution between 1 and 4 eV which is composed of two resonances observed for example for (CO₂)(4)(-) at 2.2 eV and 3.1 eV (peak maxima). While the complexes observed around 3.1 eV are generated via the (2)Π(u) resonance as precursor with subsequent intracluster relaxation, the contribution around 2.2 eV can be associated with a resonant scattering feature, recently discovered in single CO₂ in the selective excitation of the higher energy member of the well known Fermi dyad [M. Allan, Phys. Rev. Lett., 2001, 87, 0332012]. Formation of (CO₂)(n)(-) in the threshold region involves vibrational Feshbach resonances (VFRs) as previously discovered via an ultrahigh resolution (1 meV) laser photoelectron attachment method [E. Leber, S. Barsotti, I. I. Fabrikant, J. M. Weber, M.-W. Ruf and H. Hotop, Eur. Phys. J. D, 2000, 12, 125]. The complexes (CO₂)(n)O(-) clearly arise from DEA at an individual molecule within the cluster involving both the (2)Π(u) and the core excited resonance. PMID:21491691

  5. Toward high-resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Palanker, Daniel; Huie, Philip; Vankov, Alexander; Asher, Alon; Baccus, Steven

    2005-04-01

    It has been already demonstrated that electrical stimulation of retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. Current retinal implants provide very low resolution (just a few electrodes), while several thousand pixels are required for functional restoration of sight. We present a design of the optoelectronic retinal prosthetic system that can activate a retinal stimulating array with pixel density up to 2,500 pix/mm2 (geometrically corresponding to a visual acuity of 20/80), and allows for natural eye scanning rather than scanning with a head-mounted camera. The system operates similarly to "virtual reality" imaging devices used in military and medical applications. An image from a video camera is projected by a goggle-mounted infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. Such a system provides a broad field of vision by allowing for natural eye scanning. The goggles are transparent to visible light, thus allowing for simultaneous utilization of remaining natural vision along with prosthetic stimulation. Optical control of the implant allows for simple adjustment of image processing algorithms and for learning. A major prerequisite for high resolution stimulation is the proximity of neural cells to the stimulation sites. This can be achieved with sub-retinal implants constructed in a manner that directs migration of retinal cells to target areas. Two basic implant geometries are described: perforated membranes and protruding electrode arrays. Possibility of the tactile neural stimulation is also examined.

  6. Decadal prediction with a high resolution model

    NASA Astrophysics Data System (ADS)

    Monerie, Paul-Arthur; Valcke, Sophie; Terray, Laurent; Moine, Marie-Pierre

    2016-04-01

    The ability of a high resolution coupled atmosphere-ocean general circulation model (with a horizontal resolution of the quarter degree in the ocean and of about 50 km in the atmosphere) to predict the annual means of temperature, precipitation, sea-ice volume and extent is assessed. Reasonable skill in predicting sea surface temperatures and surface air temperature is obtained, especially over the North Atlantic, the tropical Atlantic and the Indian Ocean. The skill in predicting precipitations is weaker and not significant. The Sea Ice Extent and volume are also reasonably predicted in winter (March) and summer (September). It is however argued that the skill is mainly due to the atmosphere feeding in well-mixed GHGs. The mid-90's subpolar gyre warming is assessed. The model simulates a warming of the North Atlantic Ocean, associated with an increase of the meridional heat transport, a strengthening of the North Atlantic current and a deepening of the mixed layer over the Labrador Sea. The atmosphere plays a role in the warming through a modulation of the North Atlantic Oscillation and a shrinking of the subpolar gyre. At the 3-8 years lead-time, a negative anomaly of pressure, located south of the subpolar gyre is associated with the wind speed decrease over the subpolar gyre. It prevents oceanic heat-loss and favors the northward move, from the subtropical to the subpolar gyre, of anomalously warm and salty water, leading to its warming. We finally argued that the subpolar gyre warming is triggered by the ocean dynamic but the atmosphere can contributes to its sustaining. This work is realised in the framework of the EU FP7 SPECS Project.

  7. High Resolution Ionospheric Mapping Using Spaceborne Synthetic Aperture Radars

    NASA Astrophysics Data System (ADS)

    Meyer, F. J.; Chotoo, K.; Roth, A. P.

    2012-12-01

    Spaceborne Synthetic Aperture Radars (SARs) are imaging radar systems that utilize the Doppler history of signals acquired during satellite flyby to produce high resolution images of the Earth. With modern sensors, operating at frequencies between about 1 GHz (L-band) and 10 GHz (X-band), radar images with resolutions in the meter to sub-meter range can be produced. The presence of the ionosphere is significantly affecting the propagation properties of the microwave signals transmitted by these systems, causing distortions of signal polarization and phase. These distortions can lead to a wide range of imaging artifacts including image range shifts, interferometric phase biases, loss of image focus, change of image geometry, and Faraday rotation. While these artifacts are particularly pronounced at L-band, they are still observable in data acquired at C- or even X-band. In recent years, a wealth of methods for measuring and correcting ionospheric influence were developed. These methods are self-calibration procedures that measure ionosphere-induced distortions to infer the two-dimensional TEC maps that affected the data. These TEC maps are then removed from the data to produce high performance SAR images. Besides being effective in correcting SAR observations, these self-calibration methods are producing high quality TEC information with sub-TECU sensitivity and sub-kilometer spatial resolution. The intent of this paper is to utilize SAR-derived ionospheric information and make the case for SAR as a data source for ionospheric research. After a short summary of ionosphere-induced distortions, the concept of TEC estimation from SAR is introduced. Here, the current state-of-the-art of ionospheric TEC estimation is presented, including Faraday rotation-based, interferometric, correlation-based, and autofocus-based techniques. For every approach, performance numbers are given that quantify the achievable TEC estimation accuracy as a function of system parameters, scene

  8. High Resolution Image Reconstruction from Projection of Low Resolution Images DIffering in Subpixel Shifts

    NASA Technical Reports Server (NTRS)

    Mareboyana, Manohar; Le Moigne-Stewart, Jacqueline; Bennett, Jerome

    2016-01-01

    In this paper, we demonstrate a simple algorithm that projects low resolution (LR) images differing in subpixel shifts on a high resolution (HR) also called super resolution (SR) grid. The algorithm is very effective in accuracy as well as time efficiency. A number of spatial interpolation techniques using nearest neighbor, inverse-distance weighted averages, Radial Basis Functions (RBF) etc. used in projection yield comparable results. For best accuracy of reconstructing SR image by a factor of two requires four LR images differing in four independent subpixel shifts. The algorithm has two steps: i) registration of low resolution images and (ii) shifting the low resolution images to align with reference image and projecting them on high resolution grid based on the shifts of each low resolution image using different interpolation techniques. Experiments are conducted by simulating low resolution images by subpixel shifts and subsampling of original high resolution image and the reconstructing the high resolution images from the simulated low resolution images. The results of accuracy of reconstruction are compared by using mean squared error measure between original high resolution image and reconstructed image. The algorithm was tested on remote sensing images and found to outperform previously proposed techniques such as Iterative Back Projection algorithm (IBP), Maximum Likelihood (ML), and Maximum a posterior (MAP) algorithms. The algorithm is robust and is not overly sensitive to the registration inaccuracies.

  9. High resolution image reconstruction from projection of low resolution images differing in subpixel shifts

    NASA Astrophysics Data System (ADS)

    Mareboyana, Manohar; Le Moigne, Jacqueline; Bennett, Jerome

    2016-05-01

    In this paper, we demonstrate simple algorithms that project low resolution (LR) images differing in subpixel shifts on a high resolution (HR) also called super resolution (SR) grid. The algorithms are very effective in accuracy as well as time efficiency. A number of spatial interpolation techniques using nearest neighbor, inverse-distance weighted averages, Radial Basis Functions (RBF) etc. are used in projection. For best accuracy of reconstructing SR image by a factor of two requires four LR images differing in four independent subpixel shifts. The algorithm has two steps: i) registration of low resolution images and (ii) shifting the low resolution images to align with reference image and projecting them on high resolution grid based on the shifts of each low resolution image using different interpolation techniques. Experiments are conducted by simulating low resolution images by subpixel shifts and subsampling of original high resolution image and the reconstructing the high resolution images from the simulated low resolution images. The results of accuracy of reconstruction are compared by using mean squared error measure between original high resolution image and reconstructed image. The algorithm was tested on remote sensing images and found to outperform previously proposed techniques such as Iterative Back Projection algorithm (IBP), Maximum Likelihood (ML) algorithms. The algorithms are robust and are not overly sensitive to the registration inaccuracies.

  10. High Resolution Airborne Shallow Water Mapping

    NASA Astrophysics Data System (ADS)

    Steinbacher, F.; Pfennigbauer, M.; Aufleger, M.; Ullrich, A.

    2012-07-01

    In order to meet the requirements of the European Water Framework Directive (EU-WFD), authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim) a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length) of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river bed was achieved

  11. High-resolution CCD imaging alternatives

    NASA Astrophysics Data System (ADS)

    Brown, D. L.; Acker, D. E.

    1992-08-01

    High resolution CCD color cameras have recently stimulated the interest of a large number of potential end-users for a wide range of practical applications. Real-time High Definition Television (HDTV) systems are now being used or considered for use in applications ranging from entertainment program origination through digital image storage to medical and scientific research. HDTV generation of electronic images offers significant cost and time-saving advantages over the use of film in such applications. Further in still image systems electronic image capture is faster and more efficient than conventional image scanners. The CCD still camera can capture 3-dimensional objects into the computing environment directly without having to shoot a picture on film develop it and then scan the image into a computer. 2. EXTENDING CCD TECHNOLOGY BEYOND BROADCAST Most standard production CCD sensor chips are made for broadcast-compatible systems. One popular CCD and the basis for this discussion offers arrays of roughly 750 x 580 picture elements (pixels) or a total array of approximately 435 pixels (see Fig. 1). FOR. A has developed a technique to increase the number of available pixels for a given image compared to that produced by the standard CCD itself. Using an inter-lined CCD with an overall spatial structure several times larger than the photo-sensitive sensor areas each of the CCD sensors is shifted in two dimensions in order to fill in spatial gaps between adjacent sensors.

  12. High Resolution NMR Spectroscopy of Nanocrystalline Proteins at Ultra-High Magnetic Field

    PubMed Central

    Sperling, Lindsay J.; Nieuwkoop, Andrew J.; Lipton, Andrew S.; Berthold, Deborah A.; Rienstra, Chad M.

    2010-01-01

    Magic-angle spinning (MAS) solid-state NMR (SSNMR) spectroscopy of uniformly-13C,15N labeled protein samples provides insight into atomic-resolution chemistry and structure. Data collection efficiency has advanced remarkably in the last decade; however, the study of larger proteins is still challenged by relatively low resolution in comparison to solution NMR. In this study, we present a systematic analysis of SSNMR protein spectra acquired at 11.7, 17.6 and 21.1 Tesla (1H frequencies of 500, 750, and 900 MHz). For two protein systems—GB1, a 6 kDa nanocrystalline protein and DsbA, a 21 kDa nanocrystalline protein—line narrowing is demonstrated in all spectral regions with increasing field. Resolution enhancement is greatest in the aliphatic region, including methine, methylene and methyl sites. The resolution for GB1 increases markedly as a function of field, and for DsbA, resolution in the C-C region increases by 42%, according to the number of peaks that can be uniquely picked and integrated in the 900 MHz spectra when compared to the 500 MHz spectra. Additionally, chemical exchange is uniquely observed in the highest field spectra for at least two isoleucine Cδ1 sites in DsbA. These results further illustrate the benefits of high-field MAS SSNMR spectroscopy for protein structural studies. PMID:19953303

  13. High resolution rainfall measurements around a high rise building

    NASA Astrophysics Data System (ADS)

    de Jong, Stijn; van de Giesen, Nick; Hut, Rolf

    2010-05-01

    A number of disdrometers (acoustic rain gauge) has been placed around a high rise building on a place where variation in spatial distribution of precipitation is expected, to show the advantage of high resolution rainfall measurements in a urban area. The standard recommendation for the placement of a rain gauge is that the gauge is positioned at a distance corresponding to two to four times the height of any nearby obstruction to obtain a measurement that is representative for the surrounding area. In an urban area it is almost impossible to find a location that suits this recommendation. Rain measurements in urban area with a high spatial resolution are desired, to obtain a better understanding of urban hydrology, but costs may be prohibitive. A low cost disdrometer has been developed to make it affordable to perform rain measurements with a very high spatial and temporal resolution. The disdrometer is tested around a high rise building on the Delft University of Technology campus. The faculty of Electrical Engineering, Mathematics and Computer Science (EWI) on the campus of Delft University of Technology consists of a high rise building of 90 meters and a low rise building of 15 meters. Sensors are placed on the low rise building to measure the impact of the high rise building on the spatial distribution of precipitation. In addition to the disdrometer, two other methods are used to measure precipitation differences around the high rise building. Tipping bucket rain gauges have been placed on two elevator shaft housings on the low rise building, of which one is situated in the shadow of the high rise building. Simultaneously, runoff from the elevator shafts is measured. A comparison of the different methods will be presented.

  14. The High Time Resolution Radio Sky

    NASA Astrophysics Data System (ADS)

    Thornton, D.

    2013-11-01

    Pulsars are laboratories for extreme physics unachievable on Earth. As individual sources and possible orbital companions can be used to study magnetospheric, emission, and superfluid physics, general relativistic effects, and stellar and binary evolution. As populations they exhibit a wide range of sub-types, with parameters varying by many orders of magnitude signifying fundamental differences in their evolutionary history and potential uses. There are currently around 2200 known pulsars in the Milky Way, the Magellanic clouds, and globular clusters, most of which have been discovered with radio survey observations. These observations, as well as being suitable for detecting the repeating signals from pulsars, are well suited for identifying other transient astronomical radio bursts that last just a few milliseconds that either singular in nature, or rarely repeating. Prior to the work of this thesis non-repeating radio transients at extragalactic distances had possibly been discovered, however with just one example status a real astronomical sources was in doubt. Finding more of these sources was a vital to proving they were real and to open up the universe for millisecond-duration radio astronomy. The High Time Resolution Universe survey uses the multibeam receiver on the 64-m Parkes radio telescope to search the whole visible sky for pulsars and transients. The temporal and spectral resolution of the receiver and the digital back-end enable the detection of relatively faint, and distant radio sources. From the Parkes telescope a large portion of the Galactic plane can be seen, a rich hunting ground for radio pulsars of all types, while previously poorly surveyed regions away from the Galactic plane are also covered. I have made a number of pulsar discoveries in the survey, including some rare systems. These include PSR J1226-6208, a possible double neutron star system in a remarkably circular orbit, PSR J1431-471 which is being eclipsed by its companion with

  15. High resolution scanning electron microscopy of plasmodesmata.

    PubMed

    Brecknock, Sarah; Dibbayawan, Teresa P; Vesk, Maret; Vesk, Peter A; Faulkner, Christine; Barton, Deborah A; Overall, Robyn L

    2011-10-01

    Symplastic transport occurs between neighbouring plant cells through functionally and structurally dynamic channels called plasmodesmata (PD). Relatively little is known about the composition of PD or the mechanisms that facilitate molecular transport into neighbouring cells. While transmission electron microscopy (TEM) provides 2-dimensional information about the structural components of PD, 3-dimensional information is difficult to extract from ultrathin sections. This study has exploited high-resolution scanning electron microscopy (HRSEM) to reveal the 3-dimensional morphology of PD in the cell walls of algae, ferns and higher plants. Varied patterns of PD were observed in the walls, ranging from uniformly distributed individual PD to discrete clusters. Occasionally the thick walls of the giant alga Chara were fractured, revealing the surface morphology of PD within. External structures such as spokes, spirals and mesh were observed surrounding the PD. Enzymatic digestions of cell wall components indicate that cellulose or pectin either compose or stabilise the extracellular spokes. Occasionally, the PD were fractured open and desmotubule-like structures and other particles were observed in their central regions. Our observations add weight to the argument that Chara PD contain desmotubules and are morphologically similar to higher plant PD.

  16. High-resolution imaging using endoscopic holography

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.

    1990-08-01

    Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help to their control. 1.

  17. Holographic high-resolution endoscopic image recording

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.

    1991-03-01

    Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help

  18. High vertical resolution crosswell seismic imaging

    DOEpatents

    Lazaratos, Spyridon K.

    1999-12-07

    A method for producing high vertical resolution seismic images from crosswell data is disclosed. In accordance with one aspect of the disclosure, a set of vertically spaced, generally horizontally extending continuous layers and associated nodes are defined within a region between two boreholes. The specific number of nodes is selected such that the value of a particular characteristic of the subterranean region at each of the nodes is one which can be determined from the seismic data. Once values are established at the nodes, values of the particular characteristic are assigned to positions between the node points of each layer based on the values at node within that layer and without regard to the values at node points within any other layer. A seismic map is produced using the node values and the assigned values therebetween. In accordance with another aspect of the disclosure, an approximate model of the region is established using direct arrival traveltime data. Thereafter, the approximate model is adjusted using reflected arrival data. In accordance with still another aspect of the disclosure, correction is provided for well deviation. An associated technique which provides improvements in ray tracing is also disclosed.

  19. High resolution EUV monochromator/spectrometer

    DOEpatents

    Koike, Masako

    1996-01-01

    This invention is related to a monochromator which employs a spherical mirror, a traveling plane mirror with simultaneous rotation, and a varied spacing plane grating. The divergent beam from the entrance slit is converged by the spherical mirror located at the various positions in the monochromator depending of the inventive system. To provide the meaningful diffraction efficiencies and to reduce unwanted higher order lights, the deviation angle subtending the incidence and diffraction beams for the plane grating is varied with the position of the traveling plane mirror with simultaneous rotation located in the front or back of the plane grating with wavelength scanning. The outgoing beam from the monochromator goes through the fixed exit slit and has same beam direction regardless of the scanning wavelength. The combination of properly designed motions of the plane mirror and novel varied-spacing parameters of the inventive plane grating corrects the aberrations and focuses the monochromatic spectral image on the exit slit, enabling measurements at high spectral resolution.

  20. High resolution EUV monochromator/spectrometer

    DOEpatents

    Koike, Masako

    1996-06-18

    This invention is related to a monochromator which employs a spherical mirror, a traveling plane mirror with simultaneous rotation, and a varied spacing plane grating. The divergent beam from the entrance slit is converged by the spherical mirror located at the various positions in the monochromator depending of the inventive system. To provide the meaningful diffraction efficiencies and to reduce unwanted higher order lights, the deviation angle subtending the incidence and diffraction beams for the plane grating is varied with the position of the traveling plane mirror with simultaneous rotation located in the front or back of the plane grating with wavelength scanning. The outgoing beam from the monochromator goes through the fixed exit slit and has same beam direction regardless of the scanning wavelength. The combination of properly designed motions of the plane mirror and novel varied-spacing parameters of the inventive plane grating corrects the aberrations and focuses the monochromatic spectral image on the exit slit, enabling measurements at high spectral resolution. 10 figs.

  1. Europa Ice Cliffs-High Resolution

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This view of the Conamara Chaos region on Jupiter's moon Europa shows cliffs along the edges of high-standing ice plates. The washboard texture of the older terrain has been broken into plates which are separated by material with a jumbled texture. The cliffs themselves are rough and broadly scalloped, and smooth debris shed from the cliff faces is piled along the base. For scale, the height of the cliffs and size of the scalloped indentations are comparable to the famous cliff face of Mount Rushmore in South Dakota.

    This image was taken on December 16, 1997 at a range of 900 kilometers (540 miles) by the solid state imaging system (camera) on NASA's Galileo spacecraft. North is to the top right of the picture, and the sun illuminates the surface from the east. This image, centered at approximately 8 degrees north latitude and 273 degrees west longitude, covers an area approximately 1.5 kilometers by 4 kilometers (0.9 miles by 2.4 miles). The resolution is 9 meters (30 feet) per picture element.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  2. High-resolution microwave images of Saturn

    NASA Technical Reports Server (NTRS)

    Grossman, A. W.; Muhleman, D. O.; Berge, G. L.

    1989-01-01

    An analysis of high-resolution microwave images of Saturn and Saturn's individual rings is presented. Radio interferometric observations of Saturn taken at the Very Large Array in New Mexico at wavelengths of 2 and 6 centimeters reveal interesting new features in both the atmosphere and rings. The resulting maps show an increase in brightness temperature of about 3 K from equator to pole at both wavelengths, while the 6-centimeter map shows a bright band at northern midlatitudes. The data are consistent with a radiative transfer model of the atmosphere that constrains the well-mixed, fully saturated, NH3 mixing ratio to be 0.00012 in a region just below the NH3 clouds, while the observed bright band indicates a 25 percent relative decrease of NH3 in northern midlatitudes. Brightness temperatures for the classical rings are presented. Ring brightness shows a variation with azimuth and is linearly polarized at an average value of about 5 percent. The variations in ring polarization suggest that at least 20 percent of the ring brightness is the result of a single scattering process.

  3. The High Resolution Tropospheric Ozone Residual

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2006-01-01

    The co-flight of the MLS stratospheric limb sounder and the Ozone Monitoring Instrument (OMI) provides the capability of computing the Tropospheric Ozone Residual (TOR) in much greater detail [Ziemke et al., 2006]. Using forward trajectory calculations of MLS ozone measurements combined with OMI column ozone we have developed a high horizontal resolution tropospheric ozone residual (HTOR) which can provide even more detail than the standard TOR product. HTOR is especially useful for extra-tropical studies of tropospheric ozone transport. We find that both the Pacific pollution corridor (East Asia to Alaska) and the Atlantic pollution corridor (North America east coast to Europe) are also preferred locations for strat-trop folds leading to systematic overestimates of pollution amounts. In fact, fold events appear to dominate extra-tropical Northern Hemisphere day-to-day maps of HTOR. Model estimates of the tropospheric column are in reasonable agreement with the HTOR amounts when offsets due to different tropopause height calculations are taken into consideration.

  4. Laser wavelength comparison by high resolution interferometry.

    PubMed

    Layer, H P; Deslattes, R D; Schweitzer, W G

    1976-03-01

    High resolution interferometry has been used to determine the wavelength ratio between two molecularly stabilized He-Ne lasers, one locked to a methane absorption at 3.39 microm and the other locked to the k peak of (129)I(2) at 633 nm. An optical beat frequency technique gave fractional orders while a microwave sideband method yielded the integer parts. Conventional (third derivative) peak seeking servoes stabilized both laser and cavity lengths. Reproducibility of the electronic control system and optics was a few parts in 10(12), while systematic errors associated with curvature of the cavity mirrors limited the accuracy of the wavelength ratio measurement to 2 parts in 10(10). The measured wavelength ratio of the methane stabilized He-Ne laser at 3.39 microm [P(7) line, nu(3) band] to the (129)I(2) (k peak) stabilized He-Ne laser at 633 nm was 5.359 049 260 6 (0.000 2 ppm). This ratio agrees with that calculated from the (lower accuracy) results of earlier wavelength measurements made relative to the (86)Kr standard. Its higher accuracy thus permits a provisional extension of the frequency scale based on the cesium oscillator into the visible spectrum.

  5. High-resolution microwave images of saturn.

    PubMed

    Grossman, A W; Muhleman, D O; Berge, G L

    1989-09-15

    An analysis of high-resolution microwave images of Saturn and Saturn's individual rings is presented. Radio interferometric observations of Saturn taken at the Very Large Array in New Mexico at wavelengths of 2 and 6 centimeters reveal interesting new features in both the atmosphere and rings. The resulting maps show an increase in brightness temperature of about 3 K from equator to pole at both wavelengths, while the 6-centimeter map shows a bright band at northern mid-latitudes. The data are consistent with a radiative transfer model of the atmosphere that constrains the well-mixed, fully saturated, NH(3) mixing ratio to be 1.2 x 10(-4) in a region just below the NH(3) clouds, while the observed bright band indicates a 25 percent relative decrease of NH(3) in northern mid-latitudes. Brightness temperatures for the classical rings are presented. Ring brightness shows a variation with azimuth and is linearly polarized at an average value of about 5 percent. The variations in ring polarization suggest that at least 20 percent of the ring brightness is the result of a single scattering process.

  6. High-resolution ophthalmic imaging system

    DOEpatents

    Olivier, Scot S.; Carrano, Carmen J.

    2007-12-04

    A system for providing an improved resolution retina image comprising an imaging camera for capturing a retina image and a computer system operatively connected to the imaging camera, the computer producing short exposures of the retina image and providing speckle processing of the short exposures to provide the improved resolution retina image. The system comprises the steps of capturing a retina image, producing short exposures of the retina image, and speckle processing the short exposures of the retina image to provide the improved resolution retina image.

  7. High resolution in galaxy photometry and imaging

    NASA Astrophysics Data System (ADS)

    Nieto, J.-L.; Lelievre, G.

    Techniques for increasing the resolution of ground-based photometric observations of galaxies are discussed. The theoretical limitations on resolution and their implications for choosing telescope size at a given site considered, with an emphasis on the importance of the Fried (1966) parameter r0. The techniques recommended are shortening exposure time, selection of the highest-resolution images, and a posteriori digital image processing (as opposed to active-mirror image stabilization or the cine-CCD system of Fort et al., 1984). The value of the increased resolution (by a factor of 2) achieved at Pic du Midi observatory for studies of detailed structure in extragalactic objects, for determining the distance to galaxies, and for probing the central cores of galaxies is indicated.

  8. A High-Resolution Global Climate Simulation

    SciTech Connect

    Duffy, P B

    2001-01-23

    A major factor limiting the quality and usefulness of global climate models is the coarse spatial resolution of these models. Global climate models today are typically run at resolutions of {approx}300 km (or even coarser) meaning that the smallest features represented are 300 km across. As Figure 1 shows, this resolution does not allow adequate representation of small or even large topographic features (e.g. the Sierra Nevada mountains). As a result of this and other problems, coarse-resolution global models do not come close to accurately simulating climate on regional spatial scales (e.g. within California). Results on continental and larger sales are much more realistic. An important consequence of this inability to simulate regional climate is that global climate model results cannot be used as the basis of assessments of potential societal impacts of climate change (e.g. effects on agriculture in the Central Valley, on management of water resources, etc.).

  9. High resolution fire risk mapping in Italy

    NASA Astrophysics Data System (ADS)

    Fiorucci, Paolo; Biondi, Guido; Campo, Lorenzo; D'Andrea, Mirko

    2014-05-01

    extinguishing actions, leaving more resources to improve safety in areas at risk. With the availability of fire perimeters mapped over a period spanning from 5 to 10 years, depending by the region, a procedure was defined in order to assess areas at risk with high spatial resolution (900 m2) based on objective criteria by observing past fire events. The availability of fire perimeters combined with a detailed knowledge of topography and land cover allowed to understand which are the main features involved in forest fire occurrences and their behaviour. The seasonality of the fire regime was also considered, partitioning the analysis in two macro season (November- April and May- October). In addition, the total precipitation obtained from the interpolation of 30 years-long time series from 460 raingauges and the average air temperature obtained downscaling 30 years ERA-INTERIM data series were considered. About 48000 fire perimeters which burnt about 5500 km2 were considered in the analysis. The analysis has been carried out at 30 m spatial resolution. Some important considerations relating to climate and the territorial features that characterize the fire regime at national level contribute to better understand the forest fire phenomena. These results allow to define new strategies for forest fire prevention and management extensible to other geographical areas.

  10. Single sensor processing to obtain high resolution color component signals

    NASA Technical Reports Server (NTRS)

    Glenn, William E. (Inventor)

    2010-01-01

    A method for generating color video signals representative of color images of a scene includes the following steps: focusing light from the scene on an electronic image sensor via a filter having a tri-color filter pattern; producing, from outputs of the sensor, first and second relatively low resolution luminance signals; producing, from outputs of the sensor, a relatively high resolution luminance signal; producing, from a ratio of the relatively high resolution luminance signal to the first relatively low resolution luminance signal, a high band luminance component signal; producing, from outputs of the sensor, relatively low resolution color component signals; and combining each of the relatively low resolution color component signals with the high band luminance component signal to obtain relatively high resolution color component signals.

  11. Flow-ejecta Crater in Icaria Planum - High Resolution Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Mars Global Surveyor Orbiter Camera (MOC) acquired this high resolution image of a flow ejecta crater on November 19, 1997, at 8:26 PM PST, about 18 minutes after the start the 45th orbit of Mars. The area shown is roughly 6.5 by 40.2 kilometers (4 by 25 miles), and is located near 40 degrees South latitude, 120 degrees West longitude. Features as small as 15-18 m (50-60 feet) across are visible in the picture.

    Flow ejecta craters are so named because the material blasted out of the crater during the impact process appears to have flowed across the surface of Mars. First seen in Mariner 9 images in 1973, and described in detail using Viking Orbiter images acquired in 1976-78, flow-ejecta craters are considered by many scientists to be evidence that liquid water could be found in the near-subsurface at the time the craters formed. This image, a factor of two better than any previous view of such features (and a factor of 33 better than the best Viking frame of the specific crater, 056A61), shows two smaller, pre-existing craters and the interaction of the flowing ejecta with these craters. The uppermost small crater has been over-topped and partly buried by the flow, while the flow has been diverted around the lower crater. Ridges formed where the flow 'stacked up' behind obstacles, or came to rest.

    Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  12. High-resolution fluorescence microscopy of myelin without exogenous probes.

    PubMed

    Christensen, Pia Crone; Brideau, Craig; Poon, Kelvin W C; Döring, Axinia; Yong, V Wee; Stys, Peter K

    2014-02-15

    Myelin is a critical element of the central and peripheral nervous systems of all higher vertebrates. Any disturbance in the integrity of the myelin sheath interferes with the axon's ability to conduct action potentials. Thus, the study of myelin structure and biochemistry is critically important. Accurate and even staining of myelin is often difficult because of its lipid-rich nature and multiple tight membrane wraps, hindering penetration of immunoprobes. Here we show a method of visualizing myelin that is fast, inexpensive and reliable using the cross-linking fixative glutaraldehyde that produces strong, broad-spectrum auto-fluorescence in fixed tissue. Traditionally, effort is generally aimed at eliminating this auto-fluorescence. However, we show that this intrinsic signal, which is very photostable and particularly strong in glutaraldehyde-fixed myelin, can be exploited to visualize this structure to produce very detailed images of myelin morphology. We imaged fixed rodent tissues from the central and peripheral nervous systems using spectral confocal microscopy to acquire high-resolution 3-dimensional images spanning the visual range of wavelengths (400-750 nm). Mathematical post-processing allows accurate and unequivocal separation of broadband auto-fluorescence from exogenous fluorescent probes such as DAPI and fluorescently-tagged secondary antibodies. We additionally show the feasibility of immunohistochemistry with antigen retrieval, which allows co-localization of proteins of interest together with detailed myelin morphology. The lysolecithin model of de- and remyelination is shown as an example of a practical application of this technique, which can be routinely applied when high-resolution microscopy of central or peripheral myelinated tracts is required.

  13. Large Scale, High Resolution, Mantle Dynamics Modeling

    NASA Astrophysics Data System (ADS)

    Geenen, T.; Berg, A. V.; Spakman, W.

    2007-12-01

    To model the geodynamic evolution of plate convergence, subduction and collision and to allow for a connection to various types of observational data, geophysical, geodetical and geological, we developed a 4D (space-time) numerical mantle convection code. The model is based on a spherical 3D Eulerian fem model, with quadratic elements, on top of which we constructed a 3D Lagrangian particle in cell(PIC) method. We use the PIC method to transport material properties and to incorporate a viscoelastic rheology. Since capturing small scale processes associated with localization phenomena require a high resolution, we spend a considerable effort on implementing solvers suitable to solve for models with over 100 million degrees of freedom. We implemented Additive Schwartz type ILU based methods in combination with a Krylov solver, GMRES. However we found that for problems with over 500 thousend degrees of freedom the convergence of the solver degraded severely. This observation is known from the literature [Saad, 2003] and results from the local character of the ILU preconditioner resulting in a poor approximation of the inverse of A for large A. The size of A for which ILU is no longer usable depends on the condition of A and on the amount of fill in allowed for the ILU preconditioner. We found that for our problems with over 5×105 degrees of freedom convergence became to slow to solve the system within an acceptable amount of walltime, one minute, even when allowing for considerable amount of fill in. We also implemented MUMPS and found good scaling results for problems up to 107 degrees of freedom for up to 32 CPU¡¯s. For problems with over 100 million degrees of freedom we implemented Algebraic Multigrid type methods (AMG) from the ML library [Sala, 2006]. Since multigrid methods are most effective for single parameter problems, we rebuild our model to use the SIMPLE method in the Stokes solver [Patankar, 1980]. We present scaling results from these solvers for 3D

  14. High resolution photoemission experiments on copper oxide superconductors

    NASA Astrophysics Data System (ADS)

    Rameau, Jonathan David

    The mechanism for achieving high transition temperatures (T c) in copper oxide superconductors and the nature of the mysterious "pseudogap" phase from which this phenomenon arises are two of the most pressing issues in solid state physics. High resolution angle resolved photoemission spectroscopy (ARPES), which can directly probe the momentum and energy dependence of the electronic structure of a crystal, is considered one of the foremost tools for unraveling these mysteries. In this thesis we present work on both the further development of the ARPES technique itself and the results of two experiments on the high temperature superconductor Bi2Sr2CaCu2O8+delta (BSCCO)---the drosophila of copper oxide superconductors---based upon these analytical and experimental advances. On the analytical side we have shown that the precision of any ARPES experiment can be radically enhanced by using the Lucy-Richardson method (LRM) of iterative deconvolution to remove the worst effects of experimental resolution broadening present in all ARPES spectra. On the experimental side we have constructed a deep ultraviolet laser system capable of increasing our data acquisition rate by more than an order of magnitude compared to what is possible using traditional synchrotron radiation sources at the same momentum and energy resolutions. Using the LRM, in conjunction with synchrotron radiation, spectroscopic evidence was found for the existence of incoherent Cooper pairs in underdoped BSCCO in the normal pseudogap state (above Tc). At the same time an asymmetry between the particle and hole states of BSCCO was found, implying that doped Mott insulators, of which BSCCO is a primordial example, are characterized by the presence of a Fermi-Luttinger surface, rather than a Fermi surface, as would be the case for a simple metal. This study provided the first spectroscopic evidence for either phenomenon. In our second experiment we were able to use the LRM on data acquired with the laser ARPES

  15. High resolution infrared acquisitions droning over the LUSI mud eruption.

    NASA Astrophysics Data System (ADS)

    Di Felice, Fabio; Romeo, Giovanni; Di Stefano, Giuseppe; Mazzini, Adriano

    2016-04-01

    The use of low-cost hand-held infrared (IR) thermal cameras based on uncooled micro-bolometer detector arrays became more widespread during the recent years. Thermal cameras have the ability to estimate temperature values without contact and therefore can be used in circumstances where objects are difficult or dangerous to reach such as volcanic eruptions. Since May 2006 the Indonesian LUSI mud eruption continues to spew boiling mud, water, aqueous vapor, CO2, CH4 and covers a surface of nearly 7 km2. At this locality we performed surveys over the unreachable erupting crater. In the framework of the LUSI Lab project (ERC grant n° 308126), in 2014 and 2015, we acquired high resolution infrared images using a specifically equipped remote-controlled drone flying at an altitude of m 100. The drone is equipped with GPS and an autopilot system that allows pre-programming the flying path or designing grids. The mounted thermal camera has peak spectral sensitivity in LW wavelength (μm 10) that is characterized by low water vapor and CO2 absorption. The low distance (high resolution) acquisitions have a temperature detail every cm 40, therefore it is possible to detect and observe physical phenomena such as thermodynamic behavior, hot mud and fluids emissions locations and their time shifts. Despite the harsh logistics and the continuously varying gas concentrations we managed to collect thermal images to estimate the crater zone spatial thermal variations. We applied atmosphere corrections to calculate infrared absorption by high concentration of water vapor. Thousands of images have been stitched together to obtain a mosaic of the crater zone. Regular monitoring with heat variation measurements collected, e.g. every six months, could give important information about the volcano activity estimating its evolution. A future data base of infrared high resolution and visible images stored in a web server could be a useful monitoring tool. An interesting development will be

  16. High resolution at low beam energy in the SEM: resolution measurement of a monochromated SEM.

    PubMed

    Michael, Joseph R

    2011-01-01

    The resolution of secondary electron low beam energy imaging of a scanning electron microscope equipped with a monochromator is quantitatively measured using the contrast transfer function (CTF) method. High-resolution images, with sub-nm resolutions, were produced using low beam energies. The use of a monochromator is shown to quantitatively improve the resolution of the SEM at low beam energies by limiting the chromatic aberration contribution to the electron probe size as demonstrated with calculations and images of suitable samples. Secondary electron image resolution at low beam energies is ultimately limited by noise in the images as shown by the CTFs.

  17. MULTIPULSE - high resolution and high power in one TDEM system

    NASA Astrophysics Data System (ADS)

    Chen, Tianyou; Hodges, Greg; Miles, Philip

    2015-09-01

    An airborne time domain electromagnetic (TEM) system with high resolution and great depth of exploration is desired for geological mapping as well as for mineral exploration. The MULTIPULSE technology enables an airborne TEM system to transmit a high power pulse (a half-sine, for instance) and one or multiple low power pulse(s) (trapezoid or square) within a half-cycle. The high power pulse ensures good depth of exploration and the low power pulse allows a fast transmitter current turn off and earlier off-time measurement thus providing higher frequency signals, which allows higher near-surface resolution and better sensitivity to weak conductors. The power spectrum of the MULTIPULSE waveform comprising a half-sine and a trapezoid pulse clearly shows increased power in the higher frequency range (> ~2.3 kHz) compared to that of a single half-sine waveform. The addition of the low power trapezoid pulse extends the range of the sensitivity 10-fold towards the weak conductors, expanding the geological conductivity range of a system and increasing the scope of its applications. The MULTIPULSE technology can be applied to standard single-pulse airborne TEM systems on both helicopter and fixed-wing. We field tested the HELITEM MULTIPULSE system over a wire-loop in Iroquois Falls, demonstrating the different sensitivity of the high and low power pulses to the overburden and the wire-loop. We also tested both HELITEM and GEOTEM MULTIPULSE systems over a layered oil sand geologic setting in Fort McMurray, Alberta, Canada. The results show comparable shallow geologic resolution of the MULTIPULSE to that of the RESOLVE system while maintaining superior depth of exploration, confirming the increased geological conductivity range of a system employing MULTIPULSE compared to the standard single-pulse systems.

  18. High Resolution Sensor for Nuclear Waste Characterization

    SciTech Connect

    Shah, Kanai; Higgins, William; Van Loef, Edgar V

    2006-01-23

    Gamma ray spectrometers are an important tool in the characterization of radioactive waste. Important requirements for gamma ray spectrometers used in this application include good energy resolution, high detection efficiency, compact size, light weight, portability, and low power requirements. None of the available spectrometers satisfy all of these requirements. The goal of the Phase I research was to investigate lanthanum halide and related scintillators for nuclear waste clean-up. LaBr3:Ce remains a very promising scintillator with high light yield and fast response. CeBr3 is attractive because it is very similar to LaBr3:Ce in terms of scintillation properties and also has the advantage of much lower self-radioactivity, which may be important in some applications. CeBr3 also shows slightly higher light yield at higher temperatures than LaBr3 and may be easier to produce with high uniformity in large volume since it does not require any dopants. Among the mixed lanthanum halides, the light yield of LaBrxI3-x:Ce is lower and the difference in crystal structure of the binaries (LaBr3 and LaI3) makes it difficult to grow high quality crystals of the ternary as the iodine concentration is increased. On the other hand, LaBrxCl3-x:Ce provides excellent performance. Its light output is high and it provides fast response. The crystal structures of the two binaries (LaBr3 and LaCl3) are very similar. Overall, its scintillation properties are very similar to those for LaBr3:Ce. While the gamma-ray stopping efficiency of LaBrxCl3-x:Ce is lower than that for LaBr3:Ce (primarily because the density of LaCl3 is lower than that of LaBr3), it may be easier to grow large crystals of LaBrxCl3-x:Ce than LaBr3:Ce since in some instances (for example, CdxZn1-xTe), the ternary compounds provide increased flexibility in the crystal lattice. Among the new dopants, Eu2+ and Pr3+, tried in LaBr3 host crystals, the Eu2+ doped samples exhibited low light output. This was mostly because a

  19. High Spatial Resolution Commercial Satellite Imaging Product Characterization

    NASA Technical Reports Server (NTRS)

    Ryan, Robert E.; Pagnutti, Mary; Blonski, Slawomir; Ross, Kenton W.; Stnaley, Thomas

    2005-01-01

    NASA Stennis Space Center's Remote Sensing group has been characterizing privately owned high spatial resolution multispectral imaging systems, such as IKONOS, QuickBird, and OrbView-3. Natural and man made targets were used for spatial resolution, radiometric, and geopositional characterizations. Higher spatial resolution also presents significant adjacency effects for accurate reliable radiometry.

  20. High spatial resolution restoration of IRAS images

    NASA Technical Reports Server (NTRS)

    Grasdalen, Gary L.; Inguva, R.; Dyck, H. Melvin; Canterna, R.; Hackwell, John A.

    1990-01-01

    A general technique to improve the spatial resolution of the IRAS AO data was developed at The Aerospace Corporation using the Maximum Entropy algorithm of Skilling and Gull. The technique has been applied to a variety of fields and several individual AO MACROS. With this general technique, resolutions of 15 arcsec were achieved in 12 and 25 micron images and 30 arcsec in 60 and 100 micron images. Results on galactic plane fields show that both photometric and positional accuracy achieved in the general IRAS survey are also achieved in the reconstructed images.

  1. 3-component high resolution seismic profiling, a more holistic approach

    NASA Astrophysics Data System (ADS)

    Pugin, A.; Pullan, S. E.; Hunter, J. A.; Cartwright, T.; Brewer, K.; Near Surface Geophysics

    2011-12-01

    High resolution seismic reflection methods have been extensively used throughout Canada by the Geological Survey of Canada to map buried valleys and thick unconsolidated sediment for groundwater and engineering studies. Our acquisition system consists of a landstreamer array of 48, 3-component (3-C), 30 Hz geophones mounted on sleds spaced at 0.75 m, 1.5 m or 3 m. The system is towed by a Minivib I that generates a swept signal from 20 Hz to 350 Hz at source spacings varying between 3 and 6 m. The source spacing chosen depends on the survey objectives, including the target depth and the horizontal coverage required. With these recording parameters, we typically acquire 4 to 6 line-km of data per day, making this technique a viable and cost-effective tool for regional surveying. In a single acquisition pass, the 3-C recording system has the advantage of acquiring P-wave, converted PS-wave and S-wave data. As expected, P-wave data are always best recorded on the vertical component; however, the PS and the S-wave data show various directions of polarisation from vertical to horizontal. We have observed that the velocity characteristics of the ground are a more important factor in the reflection phase polarisation than the orientation of the vibrating mass of the Minivib source. In low shear-wave velocity sediments, the polarisation of the S-wave can evolve from sub-vertical in the near surface to almost horizontal for reflections from higher-velocity sediments or bedrock, irrespective of the source orientation. In more consolidated sediments characterized by higher near surface velocities, the polarisation phase of the S-wave remains predominantly horizontal from surface to bedrock even when the source is vibrated in the vertical mode. The acquisition of 3-C shallow seismic reflection data is providing new insights into the complex behaviour and polarisation of seismic energy in the subsurface, and opening new opportunities for improving the resolution and information

  2. Mapping the electrostatic force field of single molecules from high-resolution scanning probe images

    PubMed Central

    Hapala, Prokop; Švec, Martin; Stetsovych, Oleksandr; van der Heijden, Nadine J.; Ondráček, Martin; van der Lit, Joost; Mutombo, Pingo; Swart, Ingmar; Jelínek, Pavel

    2016-01-01

    How electronic charge is distributed over a molecule determines to a large extent its chemical properties. Here, we demonstrate how the electrostatic force field, originating from the inhomogeneous charge distribution in a molecule, can be measured with submolecular resolution. We exploit the fact that distortions typically observed in high-resolution atomic force microscopy images are for a significant part caused by the electrostatic force acting between charges of the tip and the molecule of interest. By finding a geometrical transformation between two high-resolution AFM images acquired with two different tips, the electrostatic force field or potential over individual molecules and self-assemblies thereof can be reconstructed with submolecular resolution. PMID:27230940

  3. High resolution, high rate x-ray spectrometer

    DOEpatents

    Goulding, F.S.; Landis, D.A.

    1983-07-14

    It is an object of the invention to provide a pulse processing system for use with detected signals of a wide dynamic range which is capable of very high counting rates, with high throughput, with excellent energy resolution and a high signal-to-noise ratio. It is a further object to provide a pulse processing system wherein the fast channel resolving time is quite short and substantially independent of the energy of the detected signals. Another object is to provide a pulse processing system having a pile-up rejector circuit which will allow the maximum number of non-interfering pulses to be passed to the output. It is also an object of the invention to provide new methods for generating substantially symmetrically triangular pulses for use in both the main and fast channels of a pulse processing system.

  4. High Resolution Velocity Structure in Eastern Turkey

    SciTech Connect

    Pasyanos, M; Gok, R; Zor, E; Walter, W

    2004-09-03

    We investigate the crustal and upper mantle structure of eastern Turkey where the Anatolian, Arabian and Eurasian Plates meet and form a complex tectonic structure. The Bitlis suture is a continental collision zone between the Anatolian plateau and the Arabian plate. Broadband data available through the Eastern Turkey Seismic Experiment (ETSE) provided a unique opportunity for studying the high resolution velocity structure. Zor et al. found an average 46 km thick crust in Anatolian plateau using six-layered grid search inversion of the ETSE receiver functions. Receiver functions are sensitive to the velocity contrast of interfaces and the relative travel time of converted and reverberated waves between those interfaces. The interpretation of receiver function alone with many-layered parameterization may result in an apparent depth-velocity tradeoff. In order to improve previous velocity model, we employed the joint inversion method with many layered parameterization of Julia et al. (2000) to the ETSE receiver functions. In this technique, the receiver function and surface-wave observations are combined into a single algebraic equation and each data set is weighted by an estimate of the uncertainty in the observations. We consider azimuthal changes of receiver functions and have stacked them into different groups. We calculated the receiver functions using iterative time-domain deconvolution technique and surface wave group velocity dispersion curves between 10-100 sec. We are making surface wave dispersion measurements at the ETSE stations and have incorporated them into a regional group velocity model. Preliminary results indicate a strong trend in the long period group velocity in the northeast. This indicates slow upper mantle velocities in the region consistent with Pn, Sn and receiver function results. We started with both the 1-D model that is obtained with the 12 tones dam explosion shot data recorded by ETSE network and the existing receiver function

  5. High-resolution breath-hold cardiac magnetic resonance imaging

    SciTech Connect

    Liu, Yu.

    1993-01-01

    This dissertation work is composed of investigations of three methods for fast cardiac magnetic resonance imaging (MRI). These methods include (1) 2D breath-hold magnetization prepared gradient echo and fast spin-echo (FSE) cardiac imaging, (2) 3D breath-hold magnetization prepared gradient echo cardiac imaging, and (3) real-time monitoring, feedback, and triggering for breath-hold MRI. The hypothesis of this work is that high resolution 2D and 3D magnetic resonance data sets for the heart can be acquired with the combination of magnetization prepared blood suppression for gradient echo techniques and accurate breath-holding methods. The 2D method included development of magnetic resonance data acquisition for cardiac imaging. The acquisition time is within a single breath-hold of 16 seconds (assuming heart 60/min). The data acquisition is synchronized with the electrocardiogram signal. Based on consistent observations of specific small cardiac structures like the papillary muscle, trabeculae, moderator band, and coronary vessels in studies of normal volunteers, the image quality represents a significant improvement over that obtained with fast imaging methods previously. To further improve the image quality provided by the 2D method, the first 3D cardiac MRI technique was developed. This method provides even better spatial resolution for cardiac images, with a voxel size of 1.09 [times] 2.19 [times] 4 mm[sup 3]. A 3D acquisition is completed in 8 breath-holds. The data acquisition for 3D cardiac imaging requires a consistent breath-hold position to avoid respiratory artifacts. To improve the reliability of the 3DFT acquisition, a new technique called MR breath-hold feedback was developed to provide reproducible breathholding. The diaphragm location is used as the index for breath-hold reproducibility measurement. The range of the diaphragm displacement in different breath-hold is reduced from 8.3 mm without the technique, to 1.3 mm with the technique.

  6. Use of UAS Remote Sensing Data (AggieAir) to Estimate Crop ET at High Spatial Resolution

    NASA Astrophysics Data System (ADS)

    ELarab, M.; Torres, A.; Nieto Solana, H.; Kustas, W. P.; Song, L.; Alfieri, J. G.; Prueger, J. H.; McKee, L.; Anderson, M. C.; Jensen, A.; McKee, M.; Alsina, M. M.

    2015-12-01

    Estimation of the spatial distribution of evapotranspiration (ET) based on remotely sensed imagery has become useful for managing water in irrigated agricultural at various spatial scales. Currently, data acquired by conventional satellites (Landsat, ASTER, etc.) lack the needed spatial resolution to capture variability of interest to support evapotranspiration estimates. In this study, an unmanned aerial system (UAS), called AggieAirTM, was used to acquire high-resolution imagery in the visual, near infrared (0.15m resolution) and thermal infrared spectra (0.6m resolution). AggieAir flew over two study sites in Utah and Central Valley of California. The imagery was used as input to a surface energy balance model based on the Mapping Evapotranspiration with Internalized Calibration (METRIC) modeling approach. The discussion will highlight the ET estimation methodologies and the implications of having high resolution ET maps.

  7. High Resolution Surface Science at Mars

    NASA Technical Reports Server (NTRS)

    Bailey, Zachary J.; Tamppari, Leslie K.; Lock, Robert E.; Sturm, Erick J.

    2013-01-01

    The proposed mission would place a 2.4 m telescope in orbit around Mars with two focal plane instruments to obtain the highest resolution images and spectral maps of the surface to date (3-10x better than current). This investigation would make major contributions to all of the Mars Program Goals: life, climate, geology and preparation for human presence.

  8. High Resolution Infrared Spectroscopy of Molecules of Terrestrial and Planetary Interest

    NASA Technical Reports Server (NTRS)

    Freedman, Richard S.

    2001-01-01

    In collaboration with the laboratory spectroscopy group of the Ames Atmospheric Physics Research Branch (SGP), high resolution infrared spectra of molecules that are of importance for the dynamics of the earth's and other planets' atmospheres were acquired using the SGP high resolution Fourier transform spectrometer and gas handling apparatus. That data, along with data acquired using similar instrumentation at the Kitt Peak National Observatory was analyzed to determine the spectral parameters for each of the rotationally resolved transitions for each molecule. Those parameters were incorporated into existing international databases (e.g. HITRANS and GEISA) so that field measurements could be converted into quantitative information regarding the physical and chemical structures of earth and planetary atmospheres.

  9. Tree Species Classification By Multiseasonal High Resolution Satellite Data

    NASA Astrophysics Data System (ADS)

    Elatawneh, Alata; Wallner, Adelheid; Straub, Christoph; Schneider, Thomas; Knoke, Thomas

    2013-12-01

    Accurate forest tree species mapping is a fundamental issue for sustainable forest management and planning. Forest tree species mapping with the means of remote sensing data is still a topic to be investigated. The Bavaria state institute of forestry is investigating the potential of using digital aerial images for forest management purposes. However, using aerial images is still cost- and time-consuming, in addition to their acquisition restrictions. The new space-born sensor generations such as, RapidEye, with a very high temporal resolution, offering multiseasonal data have the potential to improve the forest tree species mapping. In this study, we investigated the potential of multiseasonal RapidEye data for mapping tree species in a Mid European forest in Southern Germany. The RapidEye data of level A3 were collected on ten different dates in the years 2009, 2010 and 2011. For data analysis, a model was developed, which combines the Spectral Angle Mapper technique with a 10-fold- cross-validation. The analysis succeeded to differentiate four tree species; Norway spruce (Picea abies L.), Silver Fir (Abies alba Mill.), European beech (Fagus sylvatica) and Maple (Acer pseudoplatanus). The model success was evaluated using digital aerial images acquired in the year 2009 and inventory point records from 2008/09 inventory. Model results of the multiseasonal RapidEye data analysis achieved an overall accuracy of 76%. However, the success of the model was evaluated only for all the identified species and not for the individual.

  10. High Resolution Airborne Digital Imagery for Precision Agriculture

    NASA Technical Reports Server (NTRS)

    Herwitz, Stanley R.

    1998-01-01

    The Environmental Research Aircraft and Sensor Technology (ERAST) program is a NASA initiative that seeks to demonstrate the application of cost-effective aircraft and sensor technology to private commercial ventures. In 1997-98, a series of flight-demonstrations and image acquisition efforts were conducted over the Hawaiian Islands using a remotely-piloted solar- powered platform (Pathfinder) and a fixed-wing piloted aircraft (Navajo) equipped with a Kodak DCS450 CIR (color infrared) digital camera. As an ERAST Science Team Member, I defined a set of flight lines over the largest coffee plantation in Hawaii: the Kauai Coffee Company's 4,000 acre Koloa Estate. Past studies have demonstrated the applications of airborne digital imaging to agricultural management. Few studies have examined the usefulness of high resolution airborne multispectral imagery with 10 cm pixel sizes. The Kodak digital camera integrated with ERAST's Airborne Real Time Imaging System (ARTIS) which generated multiband CCD images consisting of 6 x 106 pixel elements. At the designated flight altitude of 1,000 feet over the coffee plantation, pixel size was 10 cm. The study involved the analysis of imagery acquired on 5 March 1998 for the detection of anomalous reflectance values and for the definition of spectral signatures as indicators of tree vigor and treatment effectiveness (e.g., drip irrigation; fertilizer application).

  11. High spatial resolution spectrometry of rafting macroalgae (Sargassum)

    NASA Astrophysics Data System (ADS)

    Szekielda, Karl H.; Marmorino, George O.; Bowles, Jeffrey H.; Gillis, David

    2010-04-01

    Data with 0.4-m spatial resolution acquired ~2 km off the southeast Florida coast using the airborne Portable Hyperspectral Imager for Low-Light Spectroscopy (PHILLS) have been analyzed with the objective of identifying drifting surface macroalgae (Sargassum) through its spectral signature in at-sensor radiance. The observed spectral features of Sargassum include a peak at a wavelength of ~0.570 μm and a photosynthetic 'red edge' between 0.673 and 0.699 μm. Sargassum also exhibits high radiance in the reflected near-infrared but is impacted by the atmospheric absorption bands of water vapor at 0.720 μm and oxygen at 0.756 μm. The spectral signature is clearest and largest in amplitude where the Sargassum occurs as small surface aggregations, or rafts, which tend to lie at the downwind ends of narrow Sargassum windrows. The quantity of floating Sargassum was estimated within a single pixel by linearly mixing a spectrum of Sargassum-free water with varying percentages of a spectrum from a pixel assumed completely filled with floating plants. For our study site about 2.3% of the ocean area is classified as having some Sargassum coverage, with pixels completely filled with Sargassum being rare (only 0.2% of the classified Sargassum pixels) and pixels with the least-resolvable amount of Sargassum (~10% filled) being the most common.

  12. High-resolution full-field optical coherence tomography using high dynamic range image processing

    NASA Astrophysics Data System (ADS)

    Leong-Hoï, A.; Claveau, R.; Montgomery, P. C.; Serio, B.; Uhring, W.; Anstotz, F.; Flury, M.

    2016-04-01

    Full-field optical coherence tomography (FF-OCT) based on white-light interference microscopy, is an emerging noninvasive imaging technique for characterizing biological tissue or optical scattering media with micrometer resolution. Tomographic images can be obtained by analyzing a sequence of interferograms acquired with a camera. This is achieved by scanning an interferometric microscope objectives along the optical axis and performing appropriate signal processing for fringe envelope extraction, leading to three-dimensional imaging over depth. However, noise contained in the images can hide some important details or induce errors in the size of these details. To firstly reduce temporal and spatial noise from the camera, it is possible to apply basic image post processing methods such as image averaging, dark frame subtraction or flat field division. It has been demonstrate that this can improve the quality of microscopy images by enhancing the signal to noise ratio. In addition, the dynamic range of images can be enhanced to improve the contrast by combining images acquired with different exposure times or light intensity. This can be made possible by applying a hybrid high dynamic range (HDR) technique, which is proposed in this paper. High resolution tomographic analysis is thus performed using a combination of the above-mentioned image processing techniques. As a result, the lateral resolution of the system can be improved so as to approach the diffraction limit of the microscope as well as to increase the power of detection, thus enabling new sub-diffraction sized structures contained in a transparent layer, initially hidden by the noise, to be detected.

  13. NMR high-resolution magic angle spinning rotor design for quantification of metabolic concentrations

    NASA Astrophysics Data System (ADS)

    Holly, R.; Damyanovich, A.; Peemoeller, H.

    2006-05-01

    A new high-resolution magic angle spinning nuclear magnetic resonance technique is presented to obtain absolute metabolite concentrations of solutions. The magnetic resonance spectrum of the sample under investigation and an internal reference are acquired simultaneously, ensuring both spectra are obtained under the same experimental conditions. The robustness of the technique is demonstrated using a solution of creatine, and it is shown that the technique can obtain solution concentrations to within 7% or better.

  14. High-resolution frequency analysis as applied to the singing voice.

    PubMed

    Morsomme, D; Remacle, M; Millet, B

    1993-01-01

    We have applied high-resolution vocal frequent analysis to a population of singing voices. Two important elements have become apparent: (1) Confirmation that the singing formant originates in the resonators. This is observed especially on a low fundamental, and it is acquired through technical skill and experience. (2) Observation of the vibrato, which, isolated from the clinical study, regarding only its graphic presentation, could have been interpreted as 'abnormal'. PMID:8253452

  15. High resolution x-ray microscope

    SciTech Connect

    Gary, C. K.; Park, H.; Lombardo, L. W.; Piestrup, M. A.; Cremer, J. T.; Pantell, R. H.; Dudchik, Y. I.

    2007-04-30

    The authors present x-ray images of grid meshes and biological material obtained using a microspot x-ray tube with a multilayer optic and a 92-element parabolic compound refractive lens (CRL) made of a plastic containing only hydrogen and carbon. Images obtained using this apparatus are compared with those using an area source with a spherical lens and a spherical lens with multilayer condenser. The authors found the best image quality using the multilayer condenser with a parabolic lens, compared to images with a spherical lens and without the multilayer optics. The resolution was measured using a 155-element parabolic CRL and a multilayer condenser with the microspot tube. The experiment demonstrates about 1.1 {mu}m resolution.

  16. High Resolution non-Markovianity in NMR

    PubMed Central

    Bernardes, Nadja K.; Peterson, John P. S.; Sarthour, Roberto S.; Souza, Alexandre M.; Monken, C. H.; Roditi, Itzhak; Oliveira, Ivan S.; Santos, Marcelo F.

    2016-01-01

    Memoryless time evolutions are ubiquitous in nature but often correspond to a resolution-induced approximation, i.e. there are correlations in time whose effects are undetectable. Recent advances in the dynamical control of small quantum systems provide the ideal scenario to probe some of these effects. Here we experimentally demonstrate the precise induction of memory effects on the evolution of a quantum coin (qubit) by correlations engineered in its environment. In particular, we design a collisional model in Nuclear Magnetic Resonance (NMR) and precisely control the strength of the effects by changing the degree of correlation in the environment and its time of interaction with the qubit. We also show how these effects can be hidden by the limited resolution of the measurements performed on the qubit. The experiment reinforces NMR as a test bed for the study of open quantum systems and the simulation of their classical counterparts. PMID:27669652

  17. Single-shot and single-sensor high/super-resolution microwave imaging based on metasurface.

    PubMed

    Wang, Libo; Li, Lianlin; Li, Yunbo; Zhang, Hao Chi; Cui, Tie Jun

    2016-01-01

    Real-time high-resolution (including super-resolution) imaging with low-cost hardware is a long sought-after goal in various imaging applications. Here, we propose broadband single-shot and single-sensor high-/super-resolution imaging by using a spatio-temporal dispersive metasurface and an imaging reconstruction algorithm. The metasurface with spatio-temporal dispersive property ensures the feasibility of the single-shot and single-sensor imager for super- and high-resolution imaging, since it can convert efficiently the detailed spatial information of the probed object into one-dimensional time- or frequency-dependent signal acquired by a single sensor fixed in the far-field region. The imaging quality can be improved by applying a feature-enhanced reconstruction algorithm in post-processing, and the desired imaging resolution is related to the distance between the object and metasurface. When the object is placed in the vicinity of the metasurface, the super-resolution imaging can be realized. The proposed imaging methodology provides a unique means to perform real-time data acquisition, high-/super-resolution images without employing expensive hardware (e.g. mechanical scanner, antenna array, etc.). We expect that this methodology could make potential breakthroughs in the areas of microwave, terahertz, optical, and even ultrasound imaging.

  18. Single-shot and single-sensor high/super-resolution microwave imaging based on metasurface

    NASA Astrophysics Data System (ADS)

    Wang, Libo; Li, Lianlin; Li, Yunbo; Zhang, Hao Chi; Cui, Tie Jun

    2016-06-01

    Real-time high-resolution (including super-resolution) imaging with low-cost hardware is a long sought-after goal in various imaging applications. Here, we propose broadband single-shot and single-sensor high-/super-resolution imaging by using a spatio-temporal dispersive metasurface and an imaging reconstruction algorithm. The metasurface with spatio-temporal dispersive property ensures the feasibility of the single-shot and single-sensor imager for super- and high-resolution imaging, since it can convert efficiently the detailed spatial information of the probed object into one-dimensional time- or frequency-dependent signal acquired by a single sensor fixed in the far-field region. The imaging quality can be improved by applying a feature-enhanced reconstruction algorithm in post-processing, and the desired imaging resolution is related to the distance between the object and metasurface. When the object is placed in the vicinity of the metasurface, the super-resolution imaging can be realized. The proposed imaging methodology provides a unique means to perform real-time data acquisition, high-/super-resolution images without employing expensive hardware (e.g. mechanical scanner, antenna array, etc.). We expect that this methodology could make potential breakthroughs in the areas of microwave, terahertz, optical, and even ultrasound imaging.

  19. Single-shot and single-sensor high/super-resolution microwave imaging based on metasurface.

    PubMed

    Wang, Libo; Li, Lianlin; Li, Yunbo; Zhang, Hao Chi; Cui, Tie Jun

    2016-01-01

    Real-time high-resolution (including super-resolution) imaging with low-cost hardware is a long sought-after goal in various imaging applications. Here, we propose broadband single-shot and single-sensor high-/super-resolution imaging by using a spatio-temporal dispersive metasurface and an imaging reconstruction algorithm. The metasurface with spatio-temporal dispersive property ensures the feasibility of the single-shot and single-sensor imager for super- and high-resolution imaging, since it can convert efficiently the detailed spatial information of the probed object into one-dimensional time- or frequency-dependent signal acquired by a single sensor fixed in the far-field region. The imaging quality can be improved by applying a feature-enhanced reconstruction algorithm in post-processing, and the desired imaging resolution is related to the distance between the object and metasurface. When the object is placed in the vicinity of the metasurface, the super-resolution imaging can be realized. The proposed imaging methodology provides a unique means to perform real-time data acquisition, high-/super-resolution images without employing expensive hardware (e.g. mechanical scanner, antenna array, etc.). We expect that this methodology could make potential breakthroughs in the areas of microwave, terahertz, optical, and even ultrasound imaging. PMID:27246668

  20. Single-shot and single-sensor high/super-resolution microwave imaging based on metasurface

    PubMed Central

    Wang, Libo; Li, Lianlin; Li, Yunbo; Zhang, Hao Chi; Cui, Tie Jun

    2016-01-01

    Real-time high-resolution (including super-resolution) imaging with low-cost hardware is a long sought-after goal in various imaging applications. Here, we propose broadband single-shot and single-sensor high-/super-resolution imaging by using a spatio-temporal dispersive metasurface and an imaging reconstruction algorithm. The metasurface with spatio-temporal dispersive property ensures the feasibility of the single-shot and single-sensor imager for super- and high-resolution imaging, since it can convert efficiently the detailed spatial information of the probed object into one-dimensional time- or frequency-dependent signal acquired by a single sensor fixed in the far-field region. The imaging quality can be improved by applying a feature-enhanced reconstruction algorithm in post-processing, and the desired imaging resolution is related to the distance between the object and metasurface. When the object is placed in the vicinity of the metasurface, the super-resolution imaging can be realized. The proposed imaging methodology provides a unique means to perform real-time data acquisition, high-/super-resolution images without employing expensive hardware (e.g. mechanical scanner, antenna array, etc.). We expect that this methodology could make potential breakthroughs in the areas of microwave, terahertz, optical, and even ultrasound imaging. PMID:27246668

  1. High resolution alpha particle spectrometry through collimation

    NASA Astrophysics Data System (ADS)

    Park, Seunghoon; Kwak, Sung-Woo; Kang, Han-Byeol

    2015-06-01

    Alpha particle spectrometry with collimation is a useful method for identifying nuclear materials among various nuclides. A mesh type collimator reduces the low energy tail and broadened energy distribution by cutting off particles with a low incidence angle. The relation between the resolution and the counting efficiency can be investigated by changing a ratio of the mesh hole diameter and the collimator thickness. Through collimation, a target particle can be distinguished by a PIPS® detector under a mixture of various nuclides.

  2. EDITORIAL: High-resolution noncontact atomic force microscopy High-resolution noncontact atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Pérez, Rubén; García, Ricardo; Schwarz, Udo

    2009-06-01

    original papers authored by many of the leading groups in the field with the goal of providing a well-balanced overview on the state-of-the-art in this rapidly evolving field. These papers, many of which are based on notable presentations given during the Madrid conference, feature highlights such as (1) the development of sophisticated force spectroscopy procedures that are able to map the complete 3D tip-sample force field on different surfaces; (2) the considerable resolution improvement of Kelvin probe force microscopy (reaching, in some cases, the atomic scale), which is accompanied by a thorough, quantitative understanding of the contrast observed; (3) the perfecting of atomic resolution imaging on insulating substrates, which helps reshape our microscopic understanding of surface properties and chemical activity of these surfaces; (4) the description of instrumental and methodological developments that pave the way to the atomic-scale characterization of magnetic and electronic properties of nanostructures, and last but not least (5) the extension of dynamic imaging modes to high-resolution operation in liquids, ultimately achieving atomic resolution. The latter developments are already having a significant impact in the highly competitive field of biological imaging under physiological conditions. This special issue of Nanotechnology would not have been possible without the highly professional support from Nina Couzin, Amy Harvey, Alex Wotherspoon and the entire Nanotechnology team at IOP Publishing. We are thankful for their help in pushing this project forward. We also thank the authors who have contributed their excellent original articles to this issue, the referees whose comments have helped make the issue an accurate portrait of this rapidly moving field, and the entire NC-AFM community that continues to drive NC-AFM to new horizons.

  3. Wavelength scanning digital interference holography for high-resolution ophthalmic imaging

    NASA Astrophysics Data System (ADS)

    Potcoava, Mariana C.; Kim, M. K.; Kay, Christine N.

    2009-02-01

    An improved digital interference holography (DIH) technique suitable for fundus images is proposed. This technique incorporates a dispersion compensation algorithm to compensate for the unknown axial length of the eye. Using this instrument we acquired successfully tomographic fundus images in human eye with narrow axial resolution less than 5μm. The optic nerve head together with the surrounding retinal vasculature were constructed. We were able to quantify a depth of 84μm between the retinal fiber and the retinal pigmented epithelium layers. DIH provides high resolution 3D information which could potentially aid in guiding glaucoma diagnosis and treatment.

  4. High-resolution absorption cross sections of C2H6 at elevated temperatures

    NASA Astrophysics Data System (ADS)

    Hargreaves, Robert J.; Buzan, Eric; Dulick, Michael; Bernath, Peter F.

    2015-11-01

    Infrared absorption cross sections near 3.3 μm have been obtained for ethane, C2H6. These were acquired at elevated temperatures (up to 773 K) using a Fourier transform infrared spectrometer and tube furnace with a resolution of 0.005 cm-1. The integrated absorption was calibrated using composite infrared spectra taken from the Pacific Northwest National Laboratory (PNNL). These new measurements are the first high-resolution infrared C2H6 cross sections at elevated temperatures.

  5. Medusae Fossae Formation - High Resolution Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    An exotic terrain of wind-eroded ridges and residual smooth surfaces are seen in one of the highest resolution images ever taken of Mars from orbit. The Medusae Fossae formation is believed to be formed of the fragmental ejecta of huge explosive volcanic eruptions. When subjected to intense wind-blasting over hundreds of millions of years, this material erodes easily once the uppermost tougher crust is breached. The crust, or cap rock, can be seen in the upper right part of the picture. The finely-spaced ridges are similar to features on Earth called yardangs, which are formed by intense winds plucking individual grains from, and by wind-driven sand blasting particles off, sedimentary deposits.

    The image was taken on October 30, 1997 at 11:05 AM PST, shortly after the Mars Global Surveyor spacecraft's 31st closest approach to Mars. The image covers an area 3.6 X 21.5 km (2.2 X 13.4 miles) at 3.6 m (12 feet) per picture element--craters only 11 m (36 feet, about the size of a swimming pool) across can be seen. The best Viking view of the area (VO 1 387S34) has a resolution of 240 m/pixel, or 67 times lower resolution than the MOC frame.

    Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  6. HIGH RESOLUTION PHOTOEMISSION STUDIES OF COMPLEX MATERIALS.

    SciTech Connect

    JOHNSON,P.D.; VALLA,T.; FEDOROV,A.; REISFELD,G.; HULBERT,S.L.

    1999-10-13

    Recent instrumentation developments in photoemission are providing new insights into the physics of complex materials. With increased energy and momentum resolution, it has become possible to examine in detail different contributions to the self-energy or inverse lifetime of the photohole created in the photoexcitation process. Employing momentum distribution and energy distribution curves, a detailed study of the optimally doped cuprate, Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}, shows that the material behaves like a non-Fermi liquid with no evidence for the quasi-particles characteristic of a Fermi liquid.

  7. DSCOVR High Time Resolution Solar Wind Measurements

    NASA Technical Reports Server (NTRS)

    Szabo, Adam

    2012-01-01

    The Deep Space Climate Observatory (DSCOVR), previously known as Triana, spacecraft is expected to be launched in late 2014. It will carry a fluxgate magnetometer, Faraday Cup solar wind detector and a top-hat electron electrostatic analyzer. The Faraday Cup will provide an unprecedented 10 vectors/sec time resolution measurement of the solar wind proton and alpha reduced distribution functions. Coupled with the 40 vector/sec vector magnetometer measurements, the identification of specific wave modes in the solar wind will be possible for the first time. The science objectives and data products of the mission will be discussed.

  8. High resolution IVEM tomography of biological specimens

    SciTech Connect

    Sedat, J.W.; Agard, D.A.

    1997-02-01

    Electron tomography is a powerful tool for elucidating the three-dimensional architecture of large biological complexes and subcellular organelles. The introduction of intermediate voltage electron microscopes further extended the technique by providing the means to examine very large and non-symmetrical subcellular organelles, at resolutions beyond what would be possible using light microscopy. Recent studies using electron tomography on a variety of cellular organelles and assemblies such as centrosomes, kinetochores, and chromatin have clearly demonstrated the power of this technique for obtaining 3D structural information on non-symmetric cell components. When combined with biochemical and molecular observations, these 3D reconstructions have provided significant new insights into biological function.

  9. Comparing High Resolution Weather Forecasts to Observations

    NASA Astrophysics Data System (ADS)

    Foley, T. A.; Smith, J. A.; Raby, J. W.

    2013-12-01

    The Advanced Research version of the Weather Research and Forecasting model (WRF) is a mesoscale numerical weather prediction (NWP) system, with a horizontal grid spacing of several kilometers to several hundred kilometers. WRF can create forecasts of finer horizontal resolution by embedding a smaller domain inside the parent domain, a process called nesting. A nest may be embedded simultaneously within a coarser-resolution (parent) model run, or run independently as a separate model forecast. Army operations require weather forecasts on a scale of one kilometer or less, an area of weather modeling known as 'terra incognita' between which large eddy simulation and traditional mesoscale NWP models are applied with most confidence. Complex terrain leads to differences in surface temperature, moisture gradients, and wind speed /wind direction, and these differences are not always well-characterized by mesoscale WRF forecasts. Differences in land surface characteristics produce air flows such as mountain/valley breezes, and sea breezes that are of vital importance to Army and Air Force operations. Atmospheric effects on commercial as well as military air platforms and any associated subsystems is of critical concern, whether for commercial flight planning or for military mission execution. The traditional model verification techniques currently used aggregate the error statistics over an entire domain (such as on the order of 100km x 100km to 500km x 500km in size), techniques which produce results that often appear smoothed and may not show the value added of higher resolution WRF output at grid resolutions of 1km or less. Point verification methods can also be ineffective due to 'double counting' errors of phase and spatial nature, and failing to capture model skill in resolving mesoscale structure. More in-depth analysis of the forecast errors are needed to deduce the various sub-regimes and temporal and spatial trends which may govern the statistics in a way which

  10. High resolution obtained by photoelectric scanning techniques.

    NASA Technical Reports Server (NTRS)

    Hall, J. S.

    1972-01-01

    Several applications of linear scanning of different types of objects are described; examples include double stars, satellites, the Red Spot of Jupiter and a landing site on the moon. This technique allows one to achieve a gain of about an order of magnitude in resolution over conventional photoelectric techniques; it is also effective in providing sufficient data for removing background effects and for the application of deconvolution procedures. Brief consideration is given to two-dimensional scanning, either at the telescope or of electronographic images in the laboratory. It is suggested that some of the techniques described should be given serious consideration for space applications.

  11. High-resolution heteronuclear correlation spectroscopy based on spatial encoding and coherence transfer in inhomogeneous fields

    NASA Astrophysics Data System (ADS)

    Wang, Kaiyu; Zhang, Zhiyong; Chen, Hao; Cai, Shuhui; Chen, Zhong

    2015-11-01

    Two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy has been proven to be a powerful technique for chemical, biological, and medical studies. Heteronuclear single quantum correlation (HSQC) and heteronuclear multiple bond correlation (HMBC) are two frequently used 2D NMR methods. In combination with spatially encoded techniques, a heteronuclear 2D NMR spectrum can be acquired in several seconds and may be applied to monitoring chemical reactions. However, it is difficult to obtain high-resolution NMR spectra in inhomogeneous fields. Inspired by the idea of tracing the difference of precession frequencies between two different spins to yield high-resolution spectra, we propose a method with correlation acquisition option and J-resolved-like acquisition option to ultrafast obtain high-resolution HSQC/HMBC spectra and heteronuclear J-resolved-like spectra in inhomogeneous fields.

  12. High-resolution MRI of spinal cords by compressive sensing parallel imaging.

    PubMed

    Peng Li; Xiangdong Yu; Griffin, Jay; Levine, Jonathan M; Jim Ji

    2015-08-01

    Spinal Cord Injury (SCI) is a common injury due to diseases or accidents. Noninvasive imaging methods play a critical role in diagnosing SCI and monitoring the response to therapy. Magnetic Resonance Imaging (MRI), by the virtue of providing excellent soft tissue contrast, is the most promising imaging method for this application. However, spinal cord has a very small cross-section, which needs high-resolution images for better visualization and diagnosis. Acquiring high-resolution spinal cord MRI images requires long acquisition time due to the physical and physiological constraints. Moreover, long acquisition time makes MRI more susceptible to motion artifacts. In this paper, we studied the application of compressive sensing (CS) and parallel imaging to achieve high-resolution imaging from sparsely sampled and reduced k-space data acquired by parallel receive arrays. In particular, the studies are limited to the effects of 2D Cartesian sampling with different subsampling schemes and reduction factors. The results show that compressive sensing parallel MRI has the potential to provide high-resolution images of the spinal cord in 1/3 of the acquisition time required by the conventional methods.

  13. High-resolution ground-based spectroscopy: where and how ?

    NASA Astrophysics Data System (ADS)

    Pallavicini, R.

    2002-07-01

    An overview is presented of high-resolution optical spectrographs in operation or under development at large telescopes, with emphasis on those facilities best suited for the study of late-type stars and stellar surface inhomogeneities. Plans for the development of new high-resolution spectroscopic instruments are discussed with emphasis on the ICE spectrograph for the PEPSI spectropolarimeter at the LBT.

  14. High Resolution LTS-SQUID Microscopes

    NASA Astrophysics Data System (ADS)

    Baudenbacher, Franz; Peters, Nicholas; Wikswo, John

    2000-03-01

    We have developed a scanning superconducting quantum interference device (SQUID) microscope for imaging magnetic fields of room-temperature samples with sub-millimeter resolution. In our design, hand wound niobium pickup coils were coupled to commercially available low-temperature SQUID sensors. The SQUID sensor and the pickup coil are in the vacuum space of the cryostat separated typically less than 50μm by a thin sapphire window from the room-temperature sample. A computerized non-magnetic scanning stage with sub-micron resolution in combination with a tripod leveling system allows samples to be scanned within 10μm of the sapphire window. For a 20-turn 500μm diameter pickup coil, we achieved a field sensitivity of 350fT\\cdotHz-1/2 for frequencies above 1 Hz, and 1pT\\cdotHz-1/2 for a 10-turn 250mm coil. The SQUID microscope was used to image the distribution of time-dependent stimulus and action currents in anisotropic cardiac tissue, the remanent magnetization of the Martian meteorite ALH84001 during thermal demagnetisation, and the magnetic susceptibility of biogenic magnetite in the beak of homing pigeons.

  15. High-resolution X-ray Multilayers

    SciTech Connect

    Martynov, V.V.; Platonov, Yu.; Kazimirov, A.; Bilderback, D.H.

    2004-05-12

    Two new approaches are taken in multilayer fabrication to help bridge the gap in bandwidth between traditional multilayers (1 to 2%) and perfect crystals (0.01%). The first approach is based on creating many layers of low-contrast Al2O3/ B4C materials. The second approach is based on using multilayer structures with a small d-spacing using traditional W/B4C and Mo/B4C materials. With 8 keV x-rays on the Chess A2 beamline, we measured a bandwidth of 0.27% with a reflectivity of 40% and a Darwin width of 17 arc seconds from a 26 A d-spacing multilayer with 800 bi-layers of Al2O3/B4C using the low-contrast approach. On the other hand, the short period approach with a W/B4C multilayer and a 14.8 A d-spacing showed a resolution of 0.5 % and a reflectivity of 58.5%. Two more Mo/B4C samples with d-spacings of 15 A and 20 A showed energy resolutions of 0.25% and 0.52% with corresponding reflectivities of 39% and 66%. Thus we observe that both methods can produce useful x-ray optical components.

  16. Preliminary results from Mariner 10: High resolution images of the Moon

    NASA Technical Reports Server (NTRS)

    Robinson, Mark S.; Hawke, B. Ray; Edwards, Kay; Lucey, Paul G.; Clark, Beth E.

    1993-01-01

    In November of 1973 the Mariner 10 spacecraft acquired high resolution images of both the Earth and the Moon as it began its voyage to Venus and then Mercury. The best images had a resolution of approximately l km and were taken from an unusual viewpoint, above the lunar North Pole. At this time the Moon was illuminated such that the eastern limb, including approximately 30 degrees of the farside, was visible. Two high resolution mosaics were acquired during this period which provide excellent views of regions of the Moon poorly seen from the Earth. These include the Frigoris, Humboldtianum, Marginis, and Smythii regions. These images also covered expanses of highlands not visible from the Earth. These data were unique in that they were the only useful robotic spacecraft images of the Moon; and they remained so until December of 1990 when the Galileo spacecraft made its first encounter with the Moon. These Mariner 10 lunar images were acquired and are currently being used in conjunction with Earth-based telescopic spectra as well as Apollo and Lunar Orbiter photographic data to investigate the nature of deposits comprising the Northeast Nearside of the Moon. These Mariner 10 frames have proved useful for photogeologic, photometric, and photoclinometric analyses; they were also used in support of the second Galileo lunar encounter of December 1992.

  17. One dimension high range resolution profile of terahertz radar

    NASA Astrophysics Data System (ADS)

    Liang, Meiyan; Zeng, Bangze; Zhang, Cunlin; Zhao, Yuejin

    2012-12-01

    Step frequency signal is one of the more commonly used radar signal for high range resolution, it commonly used in radar target recognition. The wavelength of Terahertz signal is shorter than that of the microwave, so it is easy to realize the high range resolution. The paper first introduces the step frequency signal to obtain the one-dimensional distance image, and analyze the principle of high resolution range profiles of step frequency radar. Then, the 0.2THz step frequency radar systems are introduced. Finally, the high resolution range profiles are achieved by the simulation of Matlab. The simulation results show that the step frequency THz radar can reach centimeter level high resolution on stationary targets. For moving targets exist distance divergence and coupling shift. With greater speed, the greater the distortion.

  18. Modified Noise Power Ratio testing of high resolution digitizers

    SciTech Connect

    McDonald, T.S.

    1994-05-01

    A broadband, full signal range, side-by-side (tandem) test method for estimating the internal noise performance of high resolution digitizers is described and illustrated. The technique involves a re-definition of the traditional Noise Power Ratio (NPR) test, a change that not only makes this test applicable to higher resolution systems than was previously practical, but also enhances its value and flexibility. Since coherence analysis is the basis of this new definition, and since the application of coherence procedures to high resolution data poses several problems, this report discusses these problems and their resolution.

  19. High resolution spectral imagery of comets

    NASA Technical Reports Server (NTRS)

    Smith, W. H.

    1986-01-01

    C-13/C-12 data at a spectral resolution of 75,000, resolving the background interferences was obtained. Some data was obtained for N-15/N-14. In April, observations were obtained for the D/H ratio. The model analysis of these observations is beginning with the goal of presentation at the Heidelberg Halley meeting. A very large quantity of observations were obtained of both features with variations on the time scale of an hour being measured. At times, the 5577 feature dominates, and at times it is nearly absent. To date, a large body of data have been obtained for C2, NH2, (O I), and probably H2O+, CN, and from the MKO data, OH. These features can all be correlated with respect to their relative velocities and distribution at the time of observation. The Greenstein effect will be used to measure similar results for CN, OH, and few other selected molecular features.

  20. The high spectral resolution (scanning) lidar (HSRL)

    SciTech Connect

    Eloranta, E.

    1995-09-01

    Lidars enable the spatial resolution of optical depth variation in clouds. The optical depth must be inverted from the backscatter signal, a process which is complicated by the fact that both molecular and aerosol backscatter signals are present. The HSRL has the advantage of allowing these two signals to be separated. It has a huge dynamic range, allowing optical depth retrieval for t = 0.01 to 3. Depolarization is used to determine the nature of hydrometeors present. Experiments show that water clouds must almost always be taken into account during cirrus observations. An exciting new development is the possibility of measuring effective radius via diffraction peak width and variable field-of-view measurements. 2 figs.

  1. High Resolution Multimode Fiber Image Recovery

    NASA Technical Reports Server (NTRS)

    Jackson, Deborah

    2000-01-01

    The research emphasis is on developing a cost-effective method of recovering image information from small, closely confined spaces using multimode fibers. The state-of-the-art good quality-viewing fiber, which can currently be used for performing this function, is a 0.5 mm diameter bundle containing 6000 pixels at a cost of $10,000 per fiber bundle. However, these fiber bundles are very fragile and can easily break during surgical use, thereby making instrument reliability and replacement cost,a major impediment to their routine use in many applications. The advantage of working with a single multimode fiber is that it is significantly less expensive and mechanically more robust. In addition, careful choice of numerical aperture allows a higher image resolution (roughly 750,000 pixels) with a 0.5 mm diameter multimode fiber.

  2. High Spectral Resolution With Multilayer Gratings

    SciTech Connect

    Andre, J.-M.; Le Guen, K.; Jonnard, P.

    2010-04-06

    The improvement of spectral resolution brought about by the use of multilayer grating (MG) instead of multilayer mirror (MM) is analyzed. The spectrum of a complex sample containing various elements excited under electron irradiation is studied. This sample is a pellet made by pressing powders of Cu and compounds with Fe and F atoms. The MM is a Mo/B{sub 4}C periodic multilayer with a period of about 6 nm; for the MG a grating of 1 {mu}m period has been etched in the MM. It is shown that the MG can easily resolve the F Kalpha and Fe Lalpha emissions, separated by about 30 eV, whereas the MM is unable to give such a performance. A comparison with an EDS (SDD) detector is also given. It is also shown that the MG can improve the detection limit. Finally the role of the slit placed in front of the detector is discussed.

  3. A high resolution global scale groundwater model

    NASA Astrophysics Data System (ADS)

    de Graaf, I. E.; Sutanudjaja, E.; Van Beek, L. P.; Bierkens, M. F.

    2013-12-01

    As the world's largest accessible source of freshwater, groundwater plays a vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and also supplies water for agricultural and industrial activities. During times of drought, the large natural groundwater storage provides a buffer against water shortage and sustains flows to rivers and wetlands, supporting ecosystem habitats and biodiversity. Yet, the current generation of global scale hydrological models (GHMs) do not include a groundwater flow component, although it is a crucial part of the hydrological cycle. Thus, a realistic physical representation of the groundwater system that allows for the simulation of groundwater head dynamics and lateral flows is essential for GHMs that increasingly run at finer resolution. In this study we present a transient global groundwater model with a resolution of 5 arc-minutes (approximately 10 km at the equator) using MODFLOW (McDonald and Harbaugh, 1988). Aquifer schematization and properties of this groundwater model were developed from available global lithological maps and datasets (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013) combined with information about e.g. aquifer thickness and presence of less permeable, impermeable, and semi-impermeable layers. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. We validated simulated groundwater heads with observations, from North America and Australia, resulting in a coefficient of determination of 0.8 and 0.7 respectively. This shows that it is feasible to build a global groundwater model using best available

  4. Shift and Mean Algorithm for Functional Imaging with High Spatio-Temporal Resolution.

    PubMed

    Rama, Sylvain

    2015-01-01

    Understanding neuronal physiology requires to record electrical activity in many small and remote compartments such as dendrites, axon or dendritic spines. To do so, electrophysiology has long been the tool of choice, as it allows recording very subtle and fast changes in electrical activity. However, electrophysiological measurements are mostly limited to large neuronal compartments such as the neuronal soma. To overcome these limitations, optical methods have been developed, allowing the monitoring of changes in fluorescence of fluorescent reporter dyes inserted into the neuron, with a spatial resolution theoretically only limited by the dye wavelength and optical devices. However, the temporal and spatial resolutive power of functional fluorescence imaging of live neurons is often limited by a necessary trade-off between image resolution, signal to noise ratio (SNR) and speed of acquisition. Here, I propose to use a Super-Resolution Shift and Mean (S&M) algorithm previously used in image computing to improve the SNR, time sampling and spatial resolution of acquired fluorescent signals. I demonstrate the benefits of this methodology using two examples: voltage imaging of action potentials (APs) in soma and dendrites of CA3 pyramidal cells and calcium imaging in the dendritic shaft and spines of CA3 pyramidal cells. I show that this algorithm allows the recording of a broad area at low speed in order to achieve a high SNR, and then pick the signal in any small compartment and resample it at high speed. This method allows preserving both the SNR and the temporal resolution of the signal, while acquiring the original images at high spatial resolution.

  5. Shift and Mean Algorithm for Functional Imaging with High Spatio-Temporal Resolution

    PubMed Central

    Rama, Sylvain

    2015-01-01

    Understanding neuronal physiology requires to record electrical activity in many small and remote compartments such as dendrites, axon or dendritic spines. To do so, electrophysiology has long been the tool of choice, as it allows recording very subtle and fast changes in electrical activity. However, electrophysiological measurements are mostly limited to large neuronal compartments such as the neuronal soma. To overcome these limitations, optical methods have been developed, allowing the monitoring of changes in fluorescence of fluorescent reporter dyes inserted into the neuron, with a spatial resolution theoretically only limited by the dye wavelength and optical devices. However, the temporal and spatial resolutive power of functional fluorescence imaging of live neurons is often limited by a necessary trade-off between image resolution, signal to noise ratio (SNR) and speed of acquisition. Here, I propose to use a Super-Resolution Shift and Mean (S&M) algorithm previously used in image computing to improve the SNR, time sampling and spatial resolution of acquired fluorescent signals. I demonstrate the benefits of this methodology using two examples: voltage imaging of action potentials (APs) in soma and dendrites of CA3 pyramidal cells and calcium imaging in the dendritic shaft and spines of CA3 pyramidal cells. I show that this algorithm allows the recording of a broad area at low speed in order to achieve a high SNR, and then pick the signal in any small compartment and resample it at high speed. This method allows preserving both the SNR and the temporal resolution of the signal, while acquiring the original images at high spatial resolution. PMID:26635526

  6. High resolution integral holography using Fourier ptychographic approach.

    PubMed

    Li, Zhaohui; Zhang, Jianqi; Wang, Xiaorui; Liu, Delian

    2014-12-29

    An innovative approach is proposed for calculating high resolution computer generated integral holograms by using the Fourier Ptychographic (FP) algorithm. The approach initializes a high resolution complex hologram with a random guess, and then stitches together low resolution multi-view images, synthesized from the elemental images captured by integral imaging (II), to recover the high resolution hologram through an iterative retrieval with FP constrains. This paper begins with an analysis of the principle of hologram synthesis from multi-projections, followed by an accurate determination of the constrains required in the Fourier ptychographic integral-holography (FPIH). Next, the procedure of the approach is described in detail. Finally, optical reconstructions are performed and the results are demonstrated. Theoretical analysis and experiments show that our proposed approach can reconstruct 3D scenes with high resolution.

  7. Combined High Spectral Resolution Lidar and Radar Measurement of Drizzle

    NASA Astrophysics Data System (ADS)

    Eloranta, Edwin

    2015-04-01

    Marine stratus clouds are an important feature of the global climate system. Cloud lifetime is sensitive to drizzle rates. Drizzle not only removes water from the cloud but it's evaporation cools the sub-cloud layer acting to suppress convection. Accurate measurements of drizzle rates will improve our understanding of cloud maintenance. Simultaneous lidar measurements of extinction and radar backscatter allow determination of drizzle droplet particle size, liquid water content, fall velocity and water flux. However, drizzle measurements with conventional lidar are hampered by: 1)changes in the transmission of the output window caused by water accumulation on the lidar output window, 2)the difficulty of correcting the backscatter signal for atmospheric extinction and, 3)the effects of multiple scattering. High spectral resolution lidar avoids problems with window transmission and atmospheric attenuation because the backscatter is referenced to the known molecular scattering cross section at each point in the profile. Although multiple scattering degrades the direct measurement of extinction with the HSRL, it has little effect the HSRL measurement of backscatter cross section. We have developed an iterative solution that begins by estimating the extinction cross in drizzle using an assumed lidar ratio and the backscatter measurement. This is combined with the radar backscatter to make a first estimate of the particle size distribution. Mie scattering theory is then used to compute an improved lidar ratio for this particle size distribution and the new lidar ratio provides an improved extinction cross section. The calculation assumes a modified gamma distribution of sizes. The mode diameter of the distribution is fixed by the lidar-radar cross section ratio, while the width of the distribution is determined by matching the computed fall velocity of the drizzle with the observed radar Doppler velocity. The strengths and limitations of the this approach are examined

  8. High-Resolution Satellite Imagery Is an Important yet Underutilized Resource in Conservation Biology

    PubMed Central

    Boyle, Sarah A.; Kennedy, Christina M.; Torres, Julio; Colman, Karen; Pérez-Estigarribia, Pastor E.; de la Sancha, Noé U.

    2014-01-01

    Technological advances and increasing availability of high-resolution satellite imagery offer the potential for more accurate land cover classifications and pattern analyses, which could greatly improve the detection and quantification of land cover change for conservation. Such remotely-sensed products, however, are often expensive and difficult to acquire, which prohibits or reduces their use. We tested whether imagery of high spatial resolution (≤5 m) differs from lower-resolution imagery (≥30 m) in performance and extent of use for conservation applications. To assess performance, we classified land cover in a heterogeneous region of Interior Atlantic Forest in Paraguay, which has undergone recent and dramatic human-induced habitat loss and fragmentation. We used 4 m multispectral IKONOS and 30 m multispectral Landsat imagery and determined the extent to which resolution influenced the delineation of land cover classes and patch-level metrics. Higher-resolution imagery more accurately delineated cover classes, identified smaller patches, retained patch shape, and detected narrower, linear patches. To assess extent of use, we surveyed three conservation journals (Biological Conservation, Biotropica, Conservation Biology) and found limited application of high-resolution imagery in research, with only 26.8% of land cover studies analyzing satellite imagery, and of these studies only 10.4% used imagery ≤5 m resolution. Our results suggest that high-resolution imagery is warranted yet under-utilized in conservation research, but is needed to adequately monitor and evaluate forest loss and conversion, and to delineate potentially important stepping-stone fragments that may serve as corridors in a human-modified landscape. Greater access to low-cost, multiband, high-resolution satellite imagery would therefore greatly facilitate conservation management and decision-making. PMID:24466287

  9. High-resolution satellite imagery is an important yet underutilized resource in conservation biology.

    PubMed

    Boyle, Sarah A; Kennedy, Christina M; Torres, Julio; Colman, Karen; Pérez-Estigarribia, Pastor E; de la Sancha, Noé U

    2014-01-01

    Technological advances and increasing availability of high-resolution satellite imagery offer the potential for more accurate land cover classifications and pattern analyses, which could greatly improve the detection and quantification of land cover change for conservation. Such remotely-sensed products, however, are often expensive and difficult to acquire, which prohibits or reduces their use. We tested whether imagery of high spatial resolution (≤5 m) differs from lower-resolution imagery (≥30 m) in performance and extent of use for conservation applications. To assess performance, we classified land cover in a heterogeneous region of Interior Atlantic Forest in Paraguay, which has undergone recent and dramatic human-induced habitat loss and fragmentation. We used 4 m multispectral IKONOS and 30 m multispectral Landsat imagery and determined the extent to which resolution influenced the delineation of land cover classes and patch-level metrics. Higher-resolution imagery more accurately delineated cover classes, identified smaller patches, retained patch shape, and detected narrower, linear patches. To assess extent of use, we surveyed three conservation journals (Biological Conservation, Biotropica, Conservation Biology) and found limited application of high-resolution imagery in research, with only 26.8% of land cover studies analyzing satellite imagery, and of these studies only 10.4% used imagery ≤5 m resolution. Our results suggest that high-resolution imagery is warranted yet under-utilized in conservation research, but is needed to adequately monitor and evaluate forest loss and conversion, and to delineate potentially important stepping-stone fragments that may serve as corridors in a human-modified landscape. Greater access to low-cost, multiband, high-resolution satellite imagery would therefore greatly facilitate conservation management and decision-making.

  10. Whole-animal imaging with high spatio-temporal resolution

    NASA Astrophysics Data System (ADS)

    Chhetri, Raghav; Amat, Fernando; Wan, Yinan; Höckendorf, Burkhard; Lemon, William C.; Keller, Philipp J.

    2016-03-01

    We developed isotropic multiview (IsoView) light-sheet microscopy in order to image fast cellular dynamics, such as cell movements in an entire developing embryo or neuronal activity throughput an entire brain or nervous system, with high resolution in all dimensions, high imaging speeds, good physical coverage and low photo-damage. To achieve high temporal resolution and high spatial resolution at the same time, IsoView microscopy rapidly images large specimens via simultaneous light-sheet illumination and fluorescence detection along four orthogonal directions. In a post-processing step, these four views are then combined by means of high-throughput multiview deconvolution to yield images with a system resolution of ≤ 450 nm in all three dimensions. Using IsoView microscopy, we performed whole-animal functional imaging of Drosophila embryos and larvae at a spatial resolution of 1.1-2.5 μm and at a temporal resolution of 2 Hz for up to 9 hours. We also performed whole-brain functional imaging in larval zebrafish and multicolor imaging of fast cellular dynamics across entire, gastrulating Drosophila embryos with isotropic, sub-cellular resolution. Compared with conventional (spatially anisotropic) light-sheet microscopy, IsoView microscopy improves spatial resolution at least sevenfold and decreases resolution anisotropy at least threefold. Compared with existing high-resolution light-sheet techniques, such as lattice lightsheet microscopy or diSPIM, IsoView microscopy effectively doubles the penetration depth and provides subsecond temporal resolution for specimens 400-fold larger than could previously be imaged.

  11. A variety of vertical integration process for high resolution seismic imaging

    NASA Astrophysics Data System (ADS)

    Tong, S.; Liu, Y., Sr.; Wen, J.

    2015-12-01

    sustainable exploration in different waters. From the above, studying mixed high resolution data in different waters that acquired by different method is very important to exploring and developing.

  12. Ship detection from high-resolution imagery based on land masking and cloud filtering

    NASA Astrophysics Data System (ADS)

    Jin, Tianming; Zhang, Junping

    2015-12-01

    High resolution satellite images play an important role in target detection application presently. This article focuses on the ship target detection from the high resolution panchromatic images. Taking advantage of geographic information such as the coastline vector data provided by NOAA Medium Resolution Coastline program, the land region is masked which is a main noise source in ship detection process. After that, the algorithm tries to deal with the cloud noise which appears frequently in the ocean satellite images, which is another reason for false alarm. Based on the analysis of cloud noise's feature in frequency domain, we introduce a windowed noise filter to get rid of the cloud noise. With the help of morphological processing algorithms adapted to target detection, we are able to acquire ship targets in fine shapes. In addition, we display the extracted information such as length and width of ship targets in a user-friendly way i.e. a KML file interpreted by Google Earth.

  13. Emulation of LISS III images for high temporal resolution at larger swath

    NASA Astrophysics Data System (ADS)

    Rao, C. V.; Malleswara Rao, J.; Senthil Kumar, A.; Lakshmi, B.; Dadhwal, V. K.

    2014-11-01

    Space borne sensors have limited capability to acquire images at high spatial and high temporal resolutions with larger swath simultaneously. In this paper, we propose alternatives to overcome this limitation by emulating such images at ground data processing system. Resourcesat-2, one of the Indian Space Research Organization's (ISRO) mission carries Linear Imaging Self-Scanners (LISS III and LISS-IV) and an Advanced Wide-Field Sensor (AWiFS) onboard. The spatial and temporal resolutions of LISS III are 23.5 m and 24 days, and those of AWiFS are 56 m and 5 days, respectively. The 141 km swath of LISS III data is overlapped with the 740 km swath of AWiFS data at centre portion in simultaneous acquisition. Two novel approaches are proposed to emulate the LISS III image with 740 km swath at 23.5 m spatial and 5-days temporal resolutions. First approach is to emulate the synthetic LISS III images at 23.5 m spatial and 5-days temporal resolutions. Mosaic such images to cover the full 740 km swath of AWiFS for a given date. First approach is achieved through a spatio-temporal data fusion technique which depends on the previously acquired single AWiFS-LISS III image pair. Second approach assumes that the non-overlapping region of AWiFS contains similar Earth's surface features of LISS III overlapping region; then it is possible to enhance the spatial resolution of AWiFS to the spatial resolution of LISS III in the nonoverlapping region. It is achieved through a single-image-super resolution technique over Non-sub sampled Contourlet Transform. First approach is computationally efficient but it requires prior knowledge of a single AWiFS-LISS III image pair for each emulated LISS III image. That image pair is acquired before or after the prediction date. Also, first approach faces radiometric issues in the mosaic process. Second approach has high computational complexity. But it works well for the data sets which are satisfying the above basic assumption. An accuracy of

  14. A high resolution global scale groundwater model

    NASA Astrophysics Data System (ADS)

    de Graaf, Inge; Sutanudjaja, Edwin; van Beek, Rens; Bierkens, Marc

    2014-05-01

    As the world's largest accessible source of freshwater, groundwater plays a vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater storage provides a large natural buffer against water shortage and sustains flows to rivers and wetlands, supporting ecosystem habitats and biodiversity. Yet, the current generation of global scale hydrological models (GHMs) do not include a groundwater flow component, although it is a crucial part of the hydrological cycle. Thus, a realistic physical representation of the groundwater system that allows for the simulation of groundwater head dynamics and lateral flows is essential for GHMs that increasingly run at finer resolution. In this study we present a global groundwater model with a resolution of 5 arc-minutes (approximately 10 km at the equator) using MODFLOW (McDonald and Harbaugh, 1988). With this global groundwater model we eventually intend to simulate the changes in the groundwater system over time that result from variations in recharge and abstraction. Aquifer schematization and properties of this groundwater model were developed from available global lithological maps and datasets (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013), combined with our estimate of aquifer thickness for sedimentary basins. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. Based on our sensitivity analysis, in which we run the model with various hydrogeological parameter settings, we observed that most variance in groundwater

  15. High spatial and temporal resolution studies of ferroelectric thin films

    NASA Astrophysics Data System (ADS)

    Hubert, Charles Rankin, Jr.

    The subject of this thesis is the investigation of the polar structure and dynamics of ferroelectric thin films using newly developed high resolution optical, scanning- force microscopy and time-resolved methods. A technique based on confocal scanning optical microscopy (CSOM) is used to image the ferroelectric polarization of BaxSr1-xTiO 3 (BST) thin films at room temperature with sub-micron spatial resolution. Films of both paraelectric (x = 0.5) and ferroelectric ( x = 0.8) compositions show a coexistence of both paraelectric and ferroelectric phases on the smallest scale resolvable with this technique. These results suggest that non-uniform stress is responsible for the strong inhomogeneous thermal broadening of the ferroelectric phase transition, and that dielectric loss in thin films may be dominated by a relatively small fraction of nanometer-sized regions. Apertureless near-field scanning optical microscopy (ANSOM) is used to map the inhomogeneous ferroelectric polarization in BaxSr 1-xTiO3 thin films. Images of nanometer-scale ferroelectric domains in BaxSr1-xTiO3 thin films are obtained with 30 Å spatial resolution using ANSOM. The images exhibit inhomogeneities in the ferroelectric polarization over the smallest scales that can be observed, and are largely uncorrelated with topographic features. The application of an in-plane static electric field causes domain reorientation and domain-wall motion over distances as small as 40 Å. These results demonstrate the promise of ANSOM for imaging near-atomic-scale polarization fluctuations in ferroelectric materials. Interferometric ANSOM is described in detail, including a practical description of how ANSOM images are acquired. A discussion of the various contrast mechanisms in ANSOM is followed by a prescription for eliminating a certain class of topographic artifacts. For the imaging of polarization in ferroelectric thin films, the linear electro-optic effect provides the central contrast mechanism. High-resolution

  16. A high-resolution time-to-digital converter using a three-level resolution

    NASA Astrophysics Data System (ADS)

    Dehghani, Asma; Saneei, Mohsen; Mahani, Ali

    2016-08-01

    In this article, a three-level resolution Vernier delay line time-to-digital converter (TDC) was proposed. The proposed TDC core was based on the pseudo-differential digital architecture that made it insensitive to nMOS and pMOS transistor mismatches. It also employed a Vernier delay line (VDL) in conjunction with an asynchronous read-out circuitry. The time interval resolution was equal to the difference of delay between buffers of upper and lower chains. Then, via the extra chain included in the lower delay line, resolution was controlled and power consumption was reduced. This method led to high resolution and low power consumption. The measurement results of TDC showed a resolution of 4.5 ps, 12-bit output dynamic range, and integral nonlinearity of 1.5 least significant bits. This TDC achieved the consumption of 68.43 µW from 1.1-V supply.

  17. GLASS CERAMICS FOR HIGH RESOLUTION IMAGING

    SciTech Connect

    Johnson, Jackie A.; Weber, Rick; Kolesnikov, Alexander I; SCHWEIZER, Stefan

    2008-01-01

    Glass-ceramic materials are being developed for use in digital mammography systems. The materials are transparent x-ray storage phosphors, which are potentially less expensive than competing materials with superior performance. The materials do not suffer from loss of resolution and increased noise due to light scattering from grain boundaries, as do the currently available polycrystalline materials. The glass ceramics are based on Eu2+ -doped fluorochlorozirconate glasses. These can be heat treated to nucleate Eudoped barium chloride nanocrystals. The glass ceramic converts ionizing radiation (typically x-rays) into stable electronhole pairs that can be read by scanning a stimulating light beam across the glass to cause photostimulated luminescence (PSL) emission. Measurements on the materials are ongoing to elucidate structure-property relationships developed as a result of introducing rare-earth ions and modifying process conditions. Image quality measurements indicate that the current material competes with state-of-the-art x-ray imaging plates. The paper presents results on structure, properties and future directions of the materials described above.

  18. High resolution CO images of Seyfert Galaxies

    NASA Technical Reports Server (NTRS)

    Meixner, M.; Puchalsky, R.; Blitz, L.; Wright, M.

    1990-01-01

    The CO (J = 1-0) emission of three Seyfert galaxies, NGC 3227, NGC 7469, and NGC 5033 was imaged. The CO emission in NGC 3227 and NGC 7469 appears as compact structures centered on the active nuclei, containing substantial fractions of the single-dish flux. In NGC 3227, 10 percent of the CO flux detected by the interferometer is contained within the ionized narrow-line region. The unresolved molecular gas concentrations in the nucleus of NGC 3227 imply a CO mass of 65 million solar masses concentrated within a diameter less than 50 pc. The CO emission in NGC 5033 is not detected at this resolution, implying a CO structure size of 20 to 60 arcsec. Continuum emission at 2.7 mm is not detected in any of the three galaxies. In the center of NGC 7469, the H2 mass is comparable to the dynamical mass. Kinematic studies of the detected gas reveal a rotational motion of the gas in NGC 3227 and NGC 7469, allowing identification of the gas in NGC 7469 with a nuclear starburst. These data are consistent with the idea that interactions between galaxies cause gas to concentrate in their nuclei thereby feeding starburst and Seyfert activity.

  19. Updating Maps Using High Resolution Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Alrajhi, Muhamad; Shahzad Janjua, Khurram; Afroz Khan, Mohammad; Alobeid, Abdalla

    2016-06-01

    Kingdom of Saudi Arabia is one of the most dynamic countries of the world. We have witnessed a very rapid urban development's which are altering Kingdom's landscape on daily basis. In recent years a substantial increase in urban populations is observed which results in the formation of large cities. Considering this fast paced growth, it has become necessary to monitor these changes, in consideration with challenges faced by aerial photography projects. It has been observed that data obtained through aerial photography has a lifecycle of 5-years because of delay caused by extreme weather conditions and dust storms which acts as hindrances or barriers during aerial imagery acquisition, which has increased the costs of aerial survey projects. All of these circumstances require that we must consider some alternatives that can provide us easy and better ways of image acquisition in short span of time for achieving reliable accuracy and cost effectiveness. The approach of this study is to conduct an extensive comparison between different resolutions of data sets which include: Orthophoto of (10 cm) GSD, Stereo images of (50 cm) GSD and Stereo images of (1 m) GSD, for map updating. Different approaches have been applied for digitizing buildings, roads, tracks, airport, roof level changes, filling stations, buildings under construction, property boundaries, mosques buildings and parking places.

  20. High-resolution tomographic imaging of microvessels

    NASA Astrophysics Data System (ADS)

    Müller, Bert; Lang, Sabrina; Dominietto, Marco; Rudin, Markus; Schulz, Georg; Deyhle, Hans; Germann, Marco; Pfeiffer, Franz; David, Christian; Weitkamp, Timm

    2008-08-01

    Cancer belongs to the primary diseases these days. Although different successful treatments including surgery, chemical, pharmacological, and radiation therapies are established, the aggressive proliferation of cancerous cells and the related formation of blood vessels has to be better understood to develop more powerful strategies against the different kinds of cancer. Angiogenesis is one of the crucial steps for the survival and metastasis formation of malignant tumors. Although therapeutic strategies attempting to inhibit these processes are being developed, the biological regulation is still unclear. This study concentrates on the three-dimensional morphology of vessels formed in a mouse tumor xenograft model post mortem. Synchrotron radiation-based micro computed tomography (SRμCT) could provide the necessary information that is essential for validating the simulations. Using mouse and human brain tissue, the different approaches to extract the vessel tree from SRμCT data are discussed. These approaches include corrosion casting, the application of contrast agents such as barium sulfate, tissue embedding, all of them regarded as materials science based. Alternatively, phase contrast tomography was used, which gave rise to promising results but still not reaches the spatial resolution to uncover the smallest capillaries.

  1. High-Resolution MOC Image of Phobos

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. This image shows a close-up of the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater, and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite.

    Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  2. High resolution airborne geophysics at hazardous waste disposal sites

    SciTech Connect

    Beard, L.P.; Nyquist, J.E.; Doll, W.E.; Chong Foo, M.; Gamey, T.J.

    1995-06-01

    In 1994, a high resolution helicopter geophysical survey was conducted over portions of the Oak Ridge Reservation, Tennessee. The 1800 line kilometer survey included multi-frequency electromagnetic and magnetic sensors. The areas covered by the high resolution portion of the survey were selected on the basis of their importance to the environmental restoration effort and on data obtained from the reconnaissance phase of the airborne survey in which electromagnetic, magnetic, and radiometric data were collected over the entire Oak Ridge Reservation in 1992--1993. The high resolution phase had lower sensor heights, more and higher EM frequencies, and tighter line spacings than did the reconnaissance survey. When flying over exceptionally clear areas, the high resolution bird came within a few meters of the ground surface. Unfortunately, even sparse trees and power or phone lines could prevent the bird from being towed safely at low altitude, and over such areas it was more usual for it to be flown at about the same altitude as the bird in the reconnaissance survey, about 30m. Even so, the magnetometers used in the high resolution phase were 20m closer to the ground than in the reconnaissance phase because they were mounted on the tail of the bird rather than on the tow cable above the bird. The EM frequencies used in the high resolution survey ranged from 7400Hz to 67000Hz. Only the horizontal coplanar loop configuration was used in the high resolution flyovers.

  3. [Development of a high resolution simultaneous microwave plasma torch spectrometer].

    PubMed

    Jiang, Jie; Huan, Yan-Fu; Jin, Wei; Feng, Guo-Dong; Fei, Qiang; Cao, Yan-Bo; Jin, Qin-Han

    2007-11-01

    A unique high resolution simultaneous microwave plasma torch (MPT) atomic emission spectrometer was developed and studied preliminarily. Some advanced technologies were applied to the spectrometer, such as echelle grating, UV-intensified CCD array detector, adjustable microwave generator, and water cooling system for the generator, etc. The detection limits of the spectrometer for some elements were determined, the spectral resolution and pixel resolution of the spectrometer were calculated, and an analysis of a practical sample was carried out. The preliminary results demonstrate that such simultaneous spectrometer has advantages of saving sample and time, possessing high sensitivity and resolution, and low-cost for the purchase and maintenance. Taking analytical figures of merit into consideration, the high resolution simultaneous MPT spectrometer will have extended application areas and greater competition potential as compared with sequential MPT spectrometers.

  4. Aerosol Classification from High Spectral Resolution Lidar Measurements

    NASA Astrophysics Data System (ADS)

    Burton, S. P.; Hair, J. W.; Ferrare, R. A.; Hostetler, C. A.; Kahnert, M.; Vaughan, M. A.; Cook, A. L.; Harper, D. B.; Berkoff, T.; Seaman, S. T.; Collins, J. E., Jr.; Fenn, M. A.; Rogers, R. R.

    2015-12-01

    The NASA Langley airborne High Spectral Resolution Lidars, HSRL-1 and HSRL-2, have acquired large datasets of vertically resolved aerosol extinction, backscatter, and depolarization during >30 airborne field missions since 2006. The lidar measurements of aerosol intensive parameters like lidar ratio and color ratio embed information about intrinsic aerosol properties, and are combined to qualitatively classify HSRL aerosol measurements into aerosol types. Knowledge of aerosol type is important for assessing aerosol radiative forcing, and can provide useful information for source attribution studies. However, atmospheric aerosol is frequently not a single pure type, but instead is a mixture, which affects the optical and radiative properties of the aerosol. We show that aerosol intensive parameters measured by lidar can be understood using mixing rules for cases of external mixing. Beyond coarse classification and mixing between classes, variations in the lidar aerosol intensive parameters provide additional insight into aerosol processes and composition. This is illustrated by depolarization measurements at three wavelengths, 355 nm, 532 nm, and 1064 nm, made by HSRL-2. Particle depolarization ratio is an indicator of non-spherical particles. Three cases each have a significantly different spectral dependence of the depolarization ratio, related to the size of the depolarizing particles. For two dust cases, large non-spherical particles account for the depolarization of the lidar light. The spectral dependence reflects the size distribution of these particles and reveals differences in the transport histories of the two plumes. For a smoke case, the depolarization is inferred to be due to the presence of small coated soot aggregates. Interestingly, the depolarization at 355 nm is similar for this smoke case compared to the dust cases, having potential implications for the upcoming EarthCARE satellite, which will measure particle depolarization ratio only at 355 nm.

  5. Interfacial shear stress measurement using high spatial resolution multiphase PIV

    NASA Astrophysics Data System (ADS)

    André, Matthieu A.; Bardet, Philippe M.

    2015-06-01

    In multiphase flows, form drag and viscous shear stress transfer momentum between phases. For numerous environmental and man-made flows, it is of primary importance to predict this transfer at a liquid-gas interface. In its general expression, interfacial shear stress involves local velocity gradients as well as surface velocity, curvature, and surface tension gradients. It is therefore a challenging quantity to measure experimentally or compute numerically. In fact, no experimental work to date has been able to directly resolve all the terms contributing to the shear stress in the case of curved and moving surfaces. In an attempt to fully resolve the interface shear stress when surface tension gradients are negligible, high-resolution particle image velocimetry (PIV) data are acquired simultaneously on both sides of a water-air interface. The flow consists of a well-conditioned uniform and homogeneous water jet discharging in quiescent air, which exhibits two-dimensional surface waves as a result of a shear layer instability below the surface. PIV provides velocity fields in both phases, while planar laser-induced fluorescence is used to track the interface and obtain its curvature. To compute the interfacial shear stress from the data, several processing schemes are proposed and compared, using liquid and/or gas phase data. Vorticity at the surface, which relates to the shear stress through the dynamic boundary condition at the surface, is also computed and provides additional strategies for estimating the shear. The various schemes are in agreement within the experimental uncertainties, validating the methodology for experimentally resolving this demanding quantity.

  6. Tensorially consistent microleveling of high resolution full tensor gradiometry data

    NASA Astrophysics Data System (ADS)

    Schiffler, M.; Queitsch, M.; Schneider, M.; Stolz, R.; Krech, W.; Meyer, H.; Kukowski, N.

    2013-12-01

    Full Tensor Magnetic Gradiometry (FTMG) data obtained with Superconductive Quantum Interference Device (SQUID) sensors offer high resolution and a low signal-to-noise ratio. In airborne operation, processing steps for leveling of flight lines using tie-lines and subsequent micro-leveling become important. Airborne SQUID-FTMG surveys show that in magnetically calm regions the overall measurement system noise level of ≈10pT/m RMS is the main contribution to the magnetograms and line-dependent artifacts become visible. Both tie-line and micro-leveling are used to remove these artifacts (corrugations). But, in the application of these standard leveling routines - originally designed for total magnetic intensity measurements - to the tensor components independently, the tracelessness and the symmetry of the resulting corrected tensor is not preserved. We show that tie-line leveling for airborne SQUID-FTMG data can be surpassed using the presented micro-leveling algorithm and discuss how it is designed to preserve the tensor properties. The micro-leveling process is performed via a moving median filter using a geometric median which preserves the properties of the tensor either to the entire tensor at once or to its structural part (eigenvalues) and rotational part (eigenvectors or idempotences) independently. We discuss the impact on data quality for the different micro-leveling methods. At each observation point, the median along the distance of the flight line is subtracted and the median in a specific footprint radius is added. For application of this filter to the rotational states, we use quaternions and quaternion interpolation. Examples of the new processing methods on data acquired with the FTMG system will be presented in this work.

  7. High Resolution Seismic Imaging of the Brawley Seismic Fault Zone

    NASA Astrophysics Data System (ADS)

    Goldman, M.; Catchings, R. D.; Rymer, M. J.; Lohman, R. B.; McGuire, J. J.; Sickler, R. R.; Criley, C.; Rosa, C.

    2011-12-01

    In March 2010, we acquired a series of high-resolution P-wave seismic reflection and refraction data sets across faults in the Brawley seismic zone (BSZ) within the Salton Sea Geothermal Field (SSGF). Our objectives were to determine the dip, possible structural complexities, and seismic velocities within the BSZ. One dataset was 3.4 km long trending east-west, and consisted of 334 shots recorded by a 2.4 km spread of 40 hz geophones placed every 10 meters. The spread was initially laid out from the first station at the eastern end of the profile to roughly 2/3 into the profile. After about half the shots, the spread was shifted from roughly 1/3 into the profile to the last station at the western end of the profile. P-waves were generated by Betsy-Seisgun 'shots' spaced every 10 meters. Initial analysis of first breaks indicate near-surface velocities of ~500-600 meters/sec, and deeper velocities of around 2000 meters/sec. Preliminary investigation of shot gathers indicate a prominent fault that extends to the ground surface. This fault is on a projection of the Kalin fault from about 40 m to the south, and broke the surface down to the west with an approximately north-south strike during a local swarm of earthquakes in 2005 and also slipped at the surface in association with the 2010 El Mayor-Cucapah earthquake in Baja California. The dataset is part of the combined Obsidian Creep data set, and provides the most detailed, publicly available subsurface images of fault structures in the BSZ and SSGF.

  8. Distant Supernova Remnant Imaged by Chandra's High Resolution Camera

    NASA Astrophysics Data System (ADS)

    1999-09-01

    supernova." The unique capabilities of the HRC stem from the close match of its imaging capability to the focusing power of the mirrors. When used with the Chandra mirrors, the HRC will make images that reveal detail as small as one-half an arc second. This is equivalent to the ability to read a stop sign at a distance of twelve miles. The checkout period for the HRC will continue for the next few weeks, during which time the team expects to acquire images of other supernova remnants, star clusters, and starburst galaxies. To follow Chandra's progress, visit the Chandra News Web site at: http://chandra.harvard.edu AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra X-ray Observatory for NASA's Office of Space Science, NASA Headquarters, Washington, D.C. The Smithsonian Astrophysical Observatory's Chandra X-ray Center in Cambridge, Mass., manages the Chandra science program and controls the observatory for NASA. TRW Space and Electronics Group of Redondo Beach, Calif., leads the contractor team that built Chandra. High resolution digital versions of the X-ray image (300 dpi JPG, TIFF) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/photo/0050/ or via links in: http://chandra.harvard.edu

  9. Reproducible high-resolution multispectral image acquisition in dermatology

    NASA Astrophysics Data System (ADS)

    Duliu, Alexandru; Gardiazabal, José; Lasser, Tobias; Navab, Nassir

    2015-07-01

    Multispectral image acquisitions are increasingly popular in dermatology, due to their improved spectral resolution which enables better tissue discrimination. Most applications however focus on restricted regions of interest, imaging only small lesions. In this work we present and discuss an imaging framework for high-resolution multispectral imaging on large regions of interest.

  10. High resolution data base for use with MAP

    SciTech Connect

    Tapley, W.C.; Harris, D.B.

    1987-05-05

    A high resolution cartographic data base of thw World is available from the CIA. We obtained this data, extracted portions of the data, and produced cartographic files of varying resolutions. The resulting data files are of the proper format for use with MAP (2), our in-house cartographic plotting program.

  11. A high resolution global scale groundwater model

    NASA Astrophysics Data System (ADS)

    de Graaf, I. E. M.; Sutanudjaja, E. H.; van Beek, L. P. H.; Bierkens, M. F. P.

    2014-05-01

    Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolution. In this study we present a global scale groundwater model (run at 6' as dynamic steady state) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The aquifer schematization and properties were based on available global datasets of lithology and transmissivities combined with estimated aquifer thickness of an upper unconfined aquifer. The model is forced with outputs from the land-surface model PCR-GLOBWB, specifically with net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed variation in saturated conductivity causes most of the groundwater level variations. Simulated groundwater heads were validated against reported piezometer observations. The validation showed that groundwater depths are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional scale groundwater patterns and flowpaths confirm the relevance of taking lateral groundwater flow into account in GHMs. Flowpaths show inter-basin groundwater flow that can be a significant part of a basins water budget and helps to sustain river baseflow, explicitly during times of droughts. Also important aquifer systems are recharged by inter-basin groundwater flows that positively affect water

  12. High Resolution X-Ray Explorer (HIREX)

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1999-01-01

    SAO has carried out a study to determine the feasibility of building an orbiting telescope capable of resolving 7 km structure on the Sun. In order to achieve the required imaging the telescope must have a resolution 0.01 arcsec. This fact challenges the state of the art of orbiting telescopes in several areas: mirror figuring; optical metrology; optical mounting; mirror figure control; system alignment; optical stability; observatory pointing; and image stability image stability. The telescope design concept is based on a 0.6m Cassegrain-style telescope with a 240 meter effective focal length. This is achieved with 2 mirrors supported at opposite ends of a 27 m space-deployable boom. The telescope mirrors are coated with multilayers designed to reflect a broad XUV passband. A third, small mirror, near the focal plane performs the function of selecting the narrow band that is finally imaged. Image stabilization to the 0.005 a,rcsec level is achieved by active control of the secondary mirror. The primary mirror is held unadjustably to the spacecraft, its pointing set by the space- craft orientation. The secondary mirror is mounted on a 6-axis stage that permits its position to be changed to align the telescope in space. The stage is intended for intermittent adjustment, both because of its speed of travel, and the TBD alignment procedure. The third mirror is called the TXI (Tuneable X-ray Imager). It is mounted on a gimbal that permits it to be tipped over a 60 degree range, selecting between the individual wavelengths in the initial bandpass. It can also rotated completely out of the way to allow the full, broadband EUV flux to strike the focal plane.

  13. A high-throughput de novo sequencing approach for shotgun proteomics using high-resolution tandem mass spectrometry

    SciTech Connect

    Pan, Chongle; Park, Byung H; McDonald, W Hayes; Carey, Patricia A; Banfield, Jillian F.; Verberkmoes, Nathan C; Hettich, Robert {Bob} L; Samatova, Nagiza F

    2010-01-01

    Background High-resolution tandem mass spectra can now be readily acquired with hybrid instruments, such as LTQ-Orbitrap and LTQ-FT, in high-throughput shotgun proteomics workflows. The improved spectral quality enables more accurate de novo sequencing for identification of post-translational modifications and amino acid polymorphisms. Results In this study, a new de novo sequencing algorithm, called Vonode, has been developed specifically for analysis of such high-resolution tandem mass spectra. To fully exploit the high mass accuracy of these spectra, a unique scoring system is proposed to evaluate sequence tags based primarily on mass accuracy information of fragment ions. Consensus sequence tags were inferred for 11,422 spectra with an average peptide length of 5.5 residues from a total of 40,297 input spectra acquired in a 24-hour proteomics measurement of Rhodopseudomonas palustris. The accuracy of inferred consensus sequence tags was 84%. According to our comparison, the performance of Vonode was shown to be superior to the PepNovo v2.0 algorithm, in terms of the number of de novo sequenced spectra and the sequencing accuracy. Conclusions Here, we improved de novo sequencing performance by developing a new algorithm specifically for high-resolution tandem mass spectral data. The Vonode algorithm is freely available for download at http://compbio.ornl.gov/Vonode.

  14. High Resolution X-Ray Explorer (HIREX)

    NASA Technical Reports Server (NTRS)

    Goulb, Leon

    1997-01-01

    SAO is involved in a study to determine the feasibility of building an orbiting telescope capable of resolving 7 km structure on the Sun. In order to achieve the required imaging the telescope must have a resolution 0.01 arcsec. This fact challenges the state of the art of orbiting telescopes in several areas: Mirror Figuring; Optical Metrology; Optical Mounting; Mirror Figure Control; System Alignment; Optical Stability; Observatory Pointing; and Image Stability. The telescope design concept is based on a 0.6 m Gregorian-style telescope with a 240 meter effective focal length. This is achieved with 2 mirrors supported at opposite ends of a 35 m space-deployable boom. The telescope mirrors are coated with multilayers designed to reflect a broad XUV passband. A third, small mirror, near the focal plane performs the function of selecting the narrow band that is finally imaged. Image stabilization to the 0.005 arcsec level is achieved by active control of the secondary mirror. The primary mirror is held unadjustably to the spacecraft, its pointing set by the spacecraft orientation. The secondary mirror is mounted on a 6-axis stage that permits its position to be changed to align the telescope in space. The stage is intended for intermittent adjustment, both because of its speed of travel, and the TBD alignment procedure. The third mirror is called the TXI (Tuneable X-ray Imager). It is mounted on a gimbal that permits it to be tipped over a 60 degree range, selecting between the individual wavelengths in the initial bandpass. It can also rotated completely out of the way to allow the full, broadband EUV flux to strike the focal plane. Finally, the focal plane assembly is designed to rotate on the outer edge of a circle centered on the TXI mirror rotation axis. This permits the focal plane to move to the location that the TXI redirects the light once it has been set to a given wavelength response. The Engineering Study is divided into the following areas: Mirror

  15. An Evaluation of SEBAL Algorithm Using High Resolution Aircraft Data Acquired During BEAREX07

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface Energy Balance Algorithm for Land (SEBAL) computes spatially distributed surface energy fluxes and evapotranspiration (ET) rates using a combination of empirical and deterministic equations executed in a strictly hierarchical sequence. Over the past decade, SEBAL has been tested over various...

  16. High time resolution studies of upstream ions

    NASA Technical Reports Server (NTRS)

    Anderson, K. A.; Levedahl, W. K.; Lin, R. P.; Parks, G. K.

    1984-01-01

    The influence of phi, the angle between the interplanetary magnetic field and the earth-sun vector on ions and electrons in the earth's bow shock, was investigated in terms of ISEE 2 data. A small phi was associated with intermediate energy upstream ions and reduced populations of low energy, about 1.6 keV, ion fluxes. The magnitude of phi was closely related to particular, constant energy levels, e.g., a phi of 40 deg and an energy of 30 keV and a phi of 75 deg and an energy of 6 keV. Ion fluxes are high in the angles form 60-80 deg and feature energies of 55-280 keV. The acceleration process up to the high energy levels in the 1-3 min interval from upstream to downstream occurs more rapidly than could be accounted for by a first-order Fermi process.

  17. High resolution survey for topographic surveying

    NASA Astrophysics Data System (ADS)

    Luh, L. C.; Setan, H.; Majid, Z.; Chong, A. K.; Tan, Z.

    2014-02-01

    In this decade, terrestrial laser scanner (TLS) is getting popular in many fields such as reconstruction, monitoring, surveying, as-built of facilities, archaeology, and topographic surveying. This is due the high speed in data collection which is about 50,000 to 1,000,000 three-dimensional (3D) points per second at high accuracy. The main advantage of 3D representation for the data is that it is more approximate to the real world. Therefore, the aim of this paper is to show the use of High-Definition Surveying (HDS), also known as 3D laser scanning for topographic survey. This research investigates the effectiveness of using terrestrial laser scanning system for topographic survey by carrying out field test in Universiti Teknologi Malaysia (UTM), Skudai, Johor. The 3D laser scanner used in this study is a Leica ScanStation C10. Data acquisition was carried out by applying the traversing method. In this study, the result for the topographic survey is under 1st class survey. At the completion of this study, a standard of procedure was proposed for topographic data acquisition using laser scanning systems. This proposed procedure serves as a guideline for users who wish to utilize laser scanning system in topographic survey fully.

  18. Updating Object for GIS Database Information Using High Resolution Satellite Images: a Case Study Zonguldak

    NASA Astrophysics Data System (ADS)

    Alkan, M.; Arca, D.; Bayik, Ç.; Marangoz, A. M.

    2011-09-01

    Nowadays Geographic Information Systems (GIS) uses Remote Sensing (RS) data for a lot of applications. One of the application areas is the updating of the GIS database using high resolution imagery. In this context high resolution satellite imagery data is very important for many applications areas today's and future. And also, high resolution satellite imagery data will be used in many applications for different purposes. Information systems needs to high resolution imagery data for updating. Updating is very important component for the any of the GIS systems. One of this area will be updated and kept alive GIS database information. High resolution satellite imagery is used with different data base which serve map information via internet and different aims of information systems applications in future topographic and cartographic information systems will very important in our country in this sense use of the satellite images will be unavoidable. In this study explain to how is acquired to satellite images and how is use this images in information systems for object and roads. Firstly, pan-sharpened two of the IKONOS's images have been produced by fusion of high resolution PAN and MS images using PCI Geomatica v9.1 software package. Automatic object extraction has been made using eCognition v4.0.6. On the other hand, these objects have been manually digitized from high resolution images using ArcGIS v9.3. software package. Application section of in this study, satellite images data will be compared each other and GIS objects and road database. It is also determined which data is useful in Geographic Information Systems. Finally, this article explains that integration of remote sensing technology and GIS applications.

  19. High Resolution Imaging of Circumstellar Disks at Millimeter Wavelengths

    NASA Technical Reports Server (NTRS)

    Wilner, David J.

    2004-01-01

    We summarize progress on our program to use high angular resolution imaging of thermal dust continuum emission at millimeter and submillimeter wavelengths to probe the structure of protoplanetary disks and debris disks around nearby stars.

  20. Update on High-Resolution Geodetically Controlled LROC Polar Mosaics

    NASA Astrophysics Data System (ADS)

    Archinal, B.; Lee, E.; Weller, L.; Richie, J.; Edmundson, K.; Laura, J.; Robinson, M.; Speyerer, E.; Boyd, A.; Bowman-Cisneros, E.; Wagner, R.; Nefian, A.

    2015-10-01

    We describe progress on high-resolution (1 m/pixel) geodetically controlled LROC mosaics of the lunar poles, which can be used for locating illumination resources (for solar power or cold traps) or landing site and surface operations planning.

  1. High Resolution CryoFESEM of Microbial Surfaces

    NASA Astrophysics Data System (ADS)

    Erlandsen, Stanley; Lei, Ming; Martin-Lacave, Ines; Dunny, Gary; Wells, Carol

    2003-08-01

    The outer surfaces of three microorganisms, Giardia lamblia, Enterococcus faecalis, and Proteus mirabilis, were investigated by cryo-immobilization followed by sublimation of extracellular ice and cryocoating with either Pt alone or Pt plus carbon. Cryocoated samples were examined at [minus sign]125°C in either an in-lens field emission SEM or a below-the-lens field emission SEM. Cryocoating with Pt alone was sufficient for low magnification observation, but attempts to do high-resolution imaging resulted in radiolysis and cracking of the specimen surface. Double coating with Pt and carbon, in combination with high resolution backscatter electron detectors, enabled high-resolution imaging of the glycocalyx of bacteria, revealing a sponge-like network over the surface. High resolution examination of bacterial flagella also revealed a periodic substructure. Common artifacts included radiolysis leading to “cracking” of the surface, and insufficient deposition of Pt resulting in the absence of detectable surface topography.

  2. High resolution difference schemes for compressible gas dynamics

    SciTech Connect

    Woodward, P.; Colella, P.

    1980-07-30

    The advantages and disadvantages of four new high-resolution difference schemes, namely the von Neumann-Richtmyer, Godunovs, MUSCL and Glimms, for mathematically representing physical conditions in compressible gas flows are compared. (LCL)

  3. Methodology of high-resolution photography for mural condition database

    NASA Astrophysics Data System (ADS)

    Higuchi, R.; Suzuki, T.; Shibata, M.; Taniguchi, Y.

    2015-08-01

    Digital documentation is one of the most useful techniques to record the condition of cultural heritage. Recently, high-resolution images become increasingly useful because it is possible to show general views of mural paintings and also detailed mural conditions in a single image. As mural paintings are damaged by environmental stresses, it is necessary to record the details of painting condition on high-resolution base maps. Unfortunately, the cost of high-resolution photography and the difficulty of operating its instruments and software have commonly been an impediment for researchers and conservators. However, the recent development of graphic software makes its operation simpler and less expensive. In this paper, we suggest a new approach to make digital heritage inventories without special instruments, based on our recent our research project in Üzümlü church in Cappadocia, Turkey. This method enables us to achieve a high-resolution image database with low costs, short time, and limited human resources.

  4. High-Resolution Strain Analysis of the Human Heart with Fast-DENSE

    NASA Astrophysics Data System (ADS)

    Aletras, Anthony H.; Balaban, Robert S.; Wen, Han

    1999-09-01

    Single breath-hold displacement data from the human heart were acquired with fast-DENSE (fast displacement encoding with stimulated echoes) during systolic contraction at 2.5 × 2.5 mm in-plane resolution. Encoding strengths of 0.86-1.60 mm/π were utilized in order to extend the dynamic range of the phase measurements and minimize effects of physiologic and instrument noise. The noise level in strain measurements for both contraction and dilation corresponded to a strain value of 2.8%. In the human heart, strain analysis has sufficient resolution to reveal transmural variation across the left ventricular wall. Data processing required minimal user intervention and provided a rapid quantitative feedback. The intrinsic temporal integration of fast-DENSE achieves high accuracy at the expense of temporal resolution.

  5. High Resolution 3D Radar Imaging of Comet Interiors

    NASA Astrophysics Data System (ADS)

    Asphaug, E. I.; Gim, Y.; Belton, M.; Brophy, J.; Weissman, P. R.; Heggy, E.

    2012-12-01

    images of interior structure to ~20 m, and to map dielectric properties (related to internal composition) to better than 200 m throughout. This is comparable in detail to modern 3D medical ultrasound, although we emphasize that the techniques are somewhat different. An interior mass distribution is obtained through spacecraft tracking, using data acquired during the close, quiet radar orbits. This is aligned with the radar-based images of the interior, and the shape model, to contribute to the multi-dimensional 3D global view. High-resolution visible imaging provides boundary conditions and geologic context to these interior views. An infrared spectroscopy and imaging campaign upon arrival reveals the time-evolving activity of the nucleus and the structure and composition of the inner coma, and the definition of surface units. CORE is designed to obtain a total view of a comet, from the coma to the active and evolving surface to the deep interior. Its primary science goal is to obtain clear images of internal structure and dielectric composition. These will reveal how the comet was formed, what it is made of, and how it 'works'. By making global yet detailed connections from interior to exterior, this knowledge will be an important complement to the Rosetta mission, and will lay the foundation for comet nucleus sample return by revealing the areas of shallow depth to 'bedrock', and relating accessible deposits to their originating provenances within the nucleus.

  6. Microbeam X-Ray Standing Wave and High Resolution Diffraction

    SciTech Connect

    Kazimirov, A.; Bilderback, D.H.; Huang, R.; Sirenko, A.

    2004-05-12

    Post-focusing collimating optics are introduced as a tool to condition X-ray microbeams for the use in high-resolution X-ray diffraction and scattering techniques. As an example, a one-bounce imaging capillary and miniature Si(004) channel-cut crystal were used to produce a microbeam with 10 {mu}m size and an ultimate angular resolution of 2.5 arc sec. This beam was used to measure the strain in semiconductor microstructures by using X-ray high resolution diffraction and standing wave techniques to {delta}d/d < 5x10-4.

  7. AVHRR/1-FM Advanced Very High Resolution Radiometer

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The advanced very high resolution radiometer is discussed. The program covers design, construction, and test of a breadboard model, engineering model, protoflight model, mechanical/structural model, and a life test model. Special bench test and calibration equipment was developed for use on the program. The flight model program objectives were to fabricate, assemble and test four of the advanced very high resolution radiometers along with a bench cooler and collimator.

  8. Volumetric expiratory high-resolution CT of the lung.

    PubMed

    Nishino, Mizuki; Hatabu, Hiroto

    2004-11-01

    We developed a volumetric expiratory high-resolution CT (HRCT) protocol that provides combined inspiratory and expiratory volumetric imaging of the lung without increasing radiation exposure, and conducted a preliminary feasibility assessment of this protocol to evaluate diffuse lung disease with small airway abnormalities. The volumetric expiratory high-resolution CT increased the detectability of the conducting airway to the areas of air trapping (P<0.0001), and added significant information about extent and distribution of air trapping (P<0.0001).

  9. Phase contrast in high resolution electron microscopy

    DOEpatents

    Rose, H.H.

    1975-09-23

    This patent relates to a device for developing a phase contrast signal for a scanning transmission electron microscope. The lens system of the microscope is operated in a condition of defocus so that predictable alternate concentric regions of high and low electron density exist in the cone of illumination. Two phase detectors are placed beneath the object inside the cone of illumination, with the first detector having the form of a zone plate, each of its rings covering alternate regions of either higher or lower electron density. The second detector is so configured that it covers the regions of electron density not covered by the first detector. Each detector measures the number of electrons incident thereon and the signal developed by the first detector is subtracted from the signal developed by the record detector to provide a phase contrast signal. (auth)

  10. High spectral resolution image of 'Stripe'

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Another early target for the full-color capability of the Imager for Mars Pathfinder (IMP) was the rock Stripe, named for the vertical, red band on its face. Regions with different color properties include the rock face (blue), bright soil in the background (green), darker intermediate colored soil in front of the rock (red), and the vertical stripe.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  11. Building Change Detection in Very High Resolution Satellite Stereo Image Time Series

    NASA Astrophysics Data System (ADS)

    Tian, J.; Qin, R.; Cerra, D.; Reinartz, P.

    2016-06-01

    There is an increasing demand for robust methods on urban sprawl monitoring. The steadily increasing number of high resolution and multi-view sensors allows producing datasets with high temporal and spatial resolution; however, less effort has been dedicated to employ very high resolution (VHR) satellite image time series (SITS) to monitor the changes in buildings with higher accuracy. In addition, these VHR data are often acquired from different sensors. The objective of this research is to propose a robust time-series data analysis method for VHR stereo imagery. Firstly, the spatial-temporal information of the stereo imagery and the Digital Surface Models (DSMs) generated from them are combined, and building probability maps (BPM) are calculated for all acquisition dates. In the second step, an object-based change analysis is performed based on the derivative features of the BPM sets. The change consistence between object-level and pixel-level are checked to remove any outlier pixels. Results are assessed on six pairs of VHR satellite images acquired within a time span of 7 years. The evaluation results have proved the efficiency of the proposed method.

  12. Ground-based high resolution Fourier transform spectrometer and its application in Beijing

    NASA Astrophysics Data System (ADS)

    Fan, Dongdong

    2013-10-01

    The B3M-FTS instrument, inherited from ACE-FTS and PARIS, is built by Canadian ABB and Beijing Vision Sky Aerospace Co., Ltd. The B3M is a complete stand-alone spectrometer designed to operate from the ground in moderate environment. It can acquire atmospheric spectra with the Sun as back illumination. This instrument is an adapted version of the classical Michelson interferometer using an optimized optical layout, and it is a high-resolution infrared Fourier transform spectrometer operating in the 750 to 4100cm-1 spectral range. In this paper, the instrument concept of a compact, portable, high-resolution Fourier transform spectrometer is introduced. Some test results of the instrument such as ILS and SNR are presented, and the spectral resolution of 0.028cm-1 @ 750cm-1 and SNR over 100:1 are achieved. Sample atmospheric absorption spectra and corresponding retrieval results measured by the FTS are given. The B3M-FTS, with its high performance, provides the capability to monitor the atmospheric composition changes by measuring the atmospheric absorption spectra of solar radiance. Lots of measurements have been acquired at the Olympics atmospheric observation super-station. Up to now, the VMRs of near 10 trace gases have been retrieved. The success of atmospheric composition profile retrieval using the FTS measurements makes the further application of FTS type payload possible in China.

  13. A Very High Spatial Resolution Detector for Small Animal PET

    SciTech Connect

    Kanai Shah, M.S.

    2007-03-06

    Positron Emission Tomography (PET) is an in vivo analog of autoradiography and has the potential to become a powerful new tool in imaging biological processes in small laboratory animals. PET imaging of small animals can provide unique information that can help in advancement of human disease models as well as drug development. Clinical PET scanners used for human imaging are bulky, expensive and do not have adequate spatial resolution for small animal studies. Hence, dedicated, low cost instruments are required for conducting small animal studies with higher spatial resolution than what is currently achieved with clinical as well as dedicated small animal PET scanners. The goal of the proposed project is to investigate a new all solid-state detector design for small animal PET imaging. Exceptionally high spatial resolution, good timing resolution, and excellent energy resolution are expected from the proposed detector design. The Phase I project was aimed at demonstrating the feasibility of producing high performance solid-state detectors that provide high sensitivity, spatial resolution, and timing characteristics. Energy resolution characteristics of the new detector were also investigated. The goal of the Phase II project is to advance the promising solid-state detector technology for small animal PET and determine its full potential. Detectors modules will be built and characterized and finally, a bench-top small animal PET system will be assembled and evaluated.

  14. High-resolution Urban Image Classification Using Extended Features

    SciTech Connect

    Vatsavai, Raju

    2011-01-01

    High-resolution image classification poses several challenges because the typical object size is much larger than the pixel resolution. Any given pixel (spectral features at that location) by itself is not a good indicator of the object it belongs to without looking at the broader spatial footprint. Therefore most modern machine learning approaches that are based on per-pixel spectral features are not very effective in high- resolution urban image classification. One way to overcome this problem is to extract features that exploit spatial contextual information. In this study, we evaluated several features in- cluding edge density, texture, and morphology. Several machine learning schemes were tested on the features extracted from a very high-resolution remote sensing image and results were presented.

  15. High resolution single particle refinement in EMAN2.1.

    PubMed

    Bell, James M; Chen, Muyuan; Baldwin, Philip R; Ludtke, Steven J

    2016-05-01

    EMAN2.1 is a complete image processing suite for quantitative analysis of grayscale images, with a primary focus on transmission electron microscopy, with complete workflows for performing high resolution single particle reconstruction, 2-D and 3-D heterogeneity analysis, random conical tilt reconstruction and subtomogram averaging, among other tasks. In this manuscript we provide the first detailed description of the high resolution single particle analysis pipeline and the philosophy behind its approach to the reconstruction problem. High resolution refinement is a fully automated process, and involves an advanced set of heuristics to select optimal algorithms for each specific refinement task. A gold standard FSC is produced automatically as part of refinement, providing a robust resolution estimate for the final map, and this is used to optimally filter the final CTF phase and amplitude corrected structure. Additional methods are in-place to reduce model bias during refinement, and to permit cross-validation using other computational methods.

  16. High resolution single particle refinement in EMAN2.1.

    PubMed

    Bell, James M; Chen, Muyuan; Baldwin, Philip R; Ludtke, Steven J

    2016-05-01

    EMAN2.1 is a complete image processing suite for quantitative analysis of grayscale images, with a primary focus on transmission electron microscopy, with complete workflows for performing high resolution single particle reconstruction, 2-D and 3-D heterogeneity analysis, random conical tilt reconstruction and subtomogram averaging, among other tasks. In this manuscript we provide the first detailed description of the high resolution single particle analysis pipeline and the philosophy behind its approach to the reconstruction problem. High resolution refinement is a fully automated process, and involves an advanced set of heuristics to select optimal algorithms for each specific refinement task. A gold standard FSC is produced automatically as part of refinement, providing a robust resolution estimate for the final map, and this is used to optimally filter the final CTF phase and amplitude corrected structure. Additional methods are in-place to reduce model bias during refinement, and to permit cross-validation using other computational methods. PMID:26931650

  17. Microbeam High Angular Resolution Diffraction Applied to Optoelectronic Devices

    SciTech Connect

    Kazimirov, A.; Bilderback, D. H.; Sirenko, A. A.; Cai, Z.-H.; Lai, B.

    2007-01-19

    Collimating perfect crystal optics in a combination with the X-ray focusing optics has been applied to perform high angular resolution microbeam diffraction and scattering experiments on micron-size optoelectronic devices produced by modern semiconductor technology. At CHESS, we used capillary optics and perfect Si/Ge crystal(s) arrangement to perform X-ray standing waves, high angular-resolution diffraction and high resolution reciprocal space mapping analysis. At the APS, 2ID-D microscope beamline, we employed a phase zone plate producing a beam with the size of 240 nm in the horizontal plane and 350 nm in the vertical (diffraction) plane and a perfect Si (004) analyzer crystal to perform diffraction analysis of selectively grown InGaAsP and InGaAlAs-based waveguides with arc sec angular resolution.

  18. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A.; Kaplan, Selig N.; Perez-Mendez, Victor

    1992-01-01

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n type, intrinsic, p type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography.

  19. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Kaplan, S.N.; Perez-Mendez, V.

    1992-05-26

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n-type, intrinsic, p-type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography. 18 figs.

  20. High spectral resolution image of Barnacle Bill

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The rover Sojourner's first target for measurement by the Alpha-Proton-Xray Spectrometer (APXS) was the rock named Barnacle Bill, located close to the ramp down which the rover made its egress from the lander. The full spectral capability of the Imager for Mars Pathfinder (IMP), consisting of 13 wavelength filters, was used to characterize the rock's surface. The measured area is relatively dark, and is shown in blue. Nearby on the rock surface, soil material is trapped in pits (shown in red).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  1. High resolution surface plasmon microscopy for cell imaging

    NASA Astrophysics Data System (ADS)

    Argoul, F.; Monier, K.; Roland, T.; Elezgaray, J.; Berguiga, L.

    2010-04-01

    We introduce a new non-labeling high resolution microscopy method for cellular imaging. This method called SSPM (Scanning Surface Plasmon Microscopy) pushes down the resolution limit of surface plasmon resonance imaging (SPRi) to sub-micronic scales. High resolution SPRi is obtained by the surface plasmon lauching with a high numerical aperture objective lens. The advantages of SPPM compared to other high resolution SPRi's rely on three aspects; (i) the interferometric detection of the back reflected light after plasmon excitation, (ii) the twodimensional scanning of the sample for image reconstruction, (iii) the radial polarization of light, enhancing both resolution and sensitivity. This microscope can afford a lateral resolution of - 150 nm in liquid environment and - 200 nm in air. We present in this paper images of IMR90 fibroblasts obtained with SSPM in dried environment. Internal compartments such as nucleus, nucleolus, mitochondria, cellular and nuclear membrane can be recognized without labelling. We propose an interpretation of the ability of SSPM to reveal high index contrast zones by a local decomposition of the V (Z) function describing the response of the SSPM.

  2. The Potential for Bayesian Compressive Sensing to Significantly Reduce Electron Dose in High Resolution STEM Images

    SciTech Connect

    Stevens, Andrew J.; Yang, Hao; Carin, Lawrence; Arslan, Ilke; Browning, Nigel D.

    2014-02-11

    The use of high resolution imaging methods in the scanning transmission electron microscope (STEM) is limited in many cases by the sensitivity of the sample to the beam and the onset of electron beam damage (for example in the study of organic systems, in tomography and during in-situ experiments). To demonstrate that alternative strategies for image acquisition can help alleviate this beam damage issue, here we apply compressive sensing via Bayesian dictionary learning to high resolution STEM images. These experiments successively reduce the number of pixels in the image (thereby reducing the overall dose while maintaining the high resolution information) and show promising results for reconstructing images from this reduced set of randomly collected measurements. We show that this approach is valid for both atomic resolution images and nanometer resolution studies, such as those that might be used in tomography datasets, by applying the method to images of strontium titanate and zeolites. As STEM images are acquired pixel by pixel while the beam is scanned over the surface of the sample, these post acquisition manipulations of the images can, in principle, be directly implemented as a low-dose acquisition method with no change in the electron optics or alignment of the microscope itself.

  3. High temporal and high spatial resolution MR angiography (4D-MRA).

    PubMed

    Hadizadeh, D R; Marx, C; Gieseke, J; Schild, H H; Willinek, W A

    2014-09-01

    In the first decade of the twenty-first century, whole-body magnetic resonance scanners with high field strengths (and thus potentially better signal-to-noise ratios) were developed. At the same time, parallel imaging and "echo-sharing" techniques were refined to allow for increasingly high spatial and temporal resolution in dynamic magnetic resonance angiography ("time-resolved" = TR-MRA). This technological progress facilitated tracking the passage of intra-venously administered contrast agent boluses as well as the acquisition of volume data sets at high image refresh rates ("4D-MRA"). This opened doors for many new applications in non-invasive vascular imaging, including simultaneous anatomic and functional analysis of many vascular pathologies including arterio-venous malformations. Different methods were established to acquire 4D-MRA using various strategies to acquire k-space trajectories over time in order to optimize imaging according to clinical needs. These include "keyhole"-based techniques (e. g. 4D-TRAK), TRICKS - both with and without projection - and HYPR-reconstruction, TREAT, and TWIST. Some of these techniques were first introduced in the 1980 s and 1990 s, were later enhanced and modified, and finally implemented in the products of major vendors. In the last decade, a large number of studies on the clinical applications of TR-MRA was published. This manuscript provides an overview of the development of TR-MRA methods and the 4D-MRA techniques as they are currently used in the diagnosis, treatment and follow-up of vascular diseases in various parts of the body. PMID:24955647

  4. A miniature high-resolution accelerometer utilizing electron tunneling

    NASA Technical Reports Server (NTRS)

    Rockstad, Howard K.; Kenny, T. W.; Reynolds, J. K.; Kaiser, W. J.; Vanzandt, T. R.; Gabrielson, Thomas B.

    1992-01-01

    New methods have been developed to implement high-resolution position sensors based on electron tunneling. These methods allow miniaturization while utilizing the position sensitivity of electron tunneling to give high resolution. A single-element tunneling accelerometer giving a displacement resolution of 0.002 A/sq rt Hz at 10 Hz, corresponding to an acceleration resolution of 5 x 10 exp -8 g/sq rt Hz, is described. A new dual-element tunneling structure which overcomes the narrow bandwidth limitations of a single-element structure is described. A sensor with an operating range of 5 Hz to 10 kHz, which can have applications as an acoustic sensor, is discussed. Noise is analyzed for fundamental thermal vibration of the suspended masses and is compared to electronic noise. It is shown that miniature tunnel accelerometers can achieve resolution such that thermal noise in the suspended masses is the dominant cause of the resolution limit. With a proof mass of order 100 mg, noise analysis predicts limiting resolutions approaching 10 exp -9 g/sq rt Hz in a 300 Hz band and 10 exp -8 g/sq rt Hz at 1 kHz.

  5. Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system.

    PubMed

    Zeraatkar, Navid; Sajedi, Salar; Farahani, Mohammad Hossein; Arabi, Hossein; Sarkar, Saeed; Ghafarian, Pardis; Rahmim, Arman; Ay, Mohammad Reza

    2014-11-01

    The small-animal High-Resolution SPECT (HiReSPECT) is a dedicated dual-head gamma camera recently designed and developed in our laboratory for imaging of murine models. Each detector is composed of an array of 1.2 × 1.2 mm(2) (pitch) pixelated CsI(Na) crystals. Two position-sensitive photomultiplier tubes (H8500) are coupled to each head's crystal. In this paper, we report on a resolution-recovery-embedded image reconstruction code applicable to the system and present the experimental results achieved using different phantoms and mouse scans. Collimator-detector response functions (CDRFs) were measured via a pixel-driven method using capillary sources at finite distances from the head within the field of view (FOV). CDRFs were then fitted by independent Gaussian functions. Thereafter, linear interpolations were applied to the standard deviation (σ) values of the fitted Gaussians, yielding a continuous map of CDRF at varying distances from the head. A rotation-based maximum-likelihood expectation maximization (MLEM) method was used for reconstruction. A fast rotation algorithm was developed to rotate the image matrix according to the desired angle by means of pre-generated rotation maps. The experiments demonstrated improved resolution utilizing our resolution-recovery-embedded image reconstruction. While the full-width at half-maximum (FWHM) radial and tangential resolution measurements of the system were over 2 mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5 mm in some locations, they fell below 1.8 mm everywhere within the FOV using the resolution-recovery algorithm. The noise performance of the system was also acceptable; the standard deviation of the average counts per voxel in the reconstructed images was 6.6% and 8.3% without and with resolution recovery, respectively.

  6. High-resolution climate simulation of the last glacial maximum

    SciTech Connect

    Erickson III, David J

    2008-01-01

    The climate of the last glacial maximum (LGM) is simulated with a high-resolution atmospheric general circulation model, the NCAR CCM3 at spectral truncation of T170, corresponding to a grid cell size of roughly 75 km. The purpose of the study is to assess whether there are significant benefits from the higher resolution simulation compared to the lower resolution simulation associated with the role of topography. The LGM simulations were forced with modified CLIMAP sea ice distribution and sea surface temperatures (SST) reduced by 1 C, ice sheet topography, reduced CO{sub 2}, and 21,000 BP orbital parameters. The high-resolution model captures modern climate reasonably well, in particular the distribution of heavy precipitation in the tropical Pacific. For the ice age case, surface temperature simulated by the high-resolution model agrees better with those of proxy estimates than does the low-resolution model. Despite the fact that tropical SSTs were only 2.1 C less than the control run, there are many lowland tropical land areas 4-6 C colder than present. Comparison of T170 model results with the best constrained proxy temperature estimates (noble gas concentrations in groundwater) now yield no significant differences between model and observations. There are also significant upland temperature changes in the best resolved tropical mountain belt (the Andes). We provisionally attribute this result in part as resulting from decreased lateral mixing between ocean and land in a model with more model grid cells. A longstanding model-data discrepancy therefore appears to be resolved without invoking any unusual model physics. The response of the Asian summer monsoon can also be more clearly linked to local geography in the high-resolution model than in the low-resolution model; this distinction should enable more confident validation of climate proxy data with the high-resolution model. Elsewhere, an inferred salinity increase in the subtropical North Atlantic may have

  7. High temporal resolution functional MRI with partial separability model.

    PubMed

    Ngo, Giang-Chau; Holtrop, Joseph L; Fu, Maojing; Lam, Fan; Sutton, Bradley P

    2015-01-01

    Even though the hemodynamic response is a slow phenomenon, high temporal resolution in functional fMRI can enable better differentiation between the signal of interest and physiological noise or increase the statistical power of functional studies. To increase the temporal resolution, several methods have been developed to decrease the repetition time, TR, such as simultaneous multi-slice imaging and MR encephalography approaches. In this work, a method using a fast acquisition and a partial separability model is presented to achieve a multi-slice fMRI protocol at a temporal resolution of 75 ms. The method is demonstrated on a visual block task. PMID:26738022

  8. A digitally configurable measurement platform using audio cards for high-resolution electronic transport studies

    NASA Astrophysics Data System (ADS)

    Gopman, D. B.; Bedau, D.; Kent, A. D.

    2012-05-01

    We report on a software-defined digitally configurable measurement platform for determining electronic transport properties in nanostructures with small readout signals. By using a high-resolution audio analog-to-digital/digital-to-analog converter in a digitally compensated bridge configuration we significantly increase the measurement speed compared to established techniques and simultaneously acquire large and small signal characteristics. We characterize the performance (16 bit resolution, 100 dB dynamic range at 192 kS/s) and demonstrate the application of this measurement platform for studying the transport properties of spin-valve nanopillars, a two-terminal device that exhibits giant magnetoresistance and whose resistance can be switched between two levels by applied magnetic fields and by currents applied by the audio card. The high resolution and fast sampling capability permits rapid acquisition of deep statistics on the switching of a spin-valve nanopillar and reduces the time to acquire the basic properties of the device - a state-diagram showing the magnetic configurations as function of applied current and magnetic field - by orders of magnitude.

  9. A digitally configurable measurement platform using audio cards for high-resolution electronic transport studies.

    PubMed

    Gopman, D B; Bedau, D; Kent, A D

    2012-05-01

    We report on a software-defined digitally configurable measurement platform for determining electronic transport properties in nanostructures with small readout signals. By using a high-resolution audio analog-to-digital/digital-to-analog converter in a digitally compensated bridge configuration we significantly increase the measurement speed compared to established techniques and simultaneously acquire large and small signal characteristics. We characterize the performance (16 bit resolution, 100 dB dynamic range at 192 kS/s) and demonstrate the application of this measurement platform for studying the transport properties of spin-valve nanopillars, a two-terminal device that exhibits giant magnetoresistance and whose resistance can be switched between two levels by applied magnetic fields and by currents applied by the audio card. The high resolution and fast sampling capability permits rapid acquisition of deep statistics on the switching of a spin-valve nanopillar and reduces the time to acquire the basic properties of the device - a state-diagram showing the magnetic configurations as function of applied current and magnetic field - by orders of magnitude. PMID:22667635

  10. Performance of a High Resolution Cavity Beam Position Monitor System

    SciTech Connect

    Walston, Sean; Boogert, Stewart; Chung, Carl; Fitsos, Joe; Frisch, Joe; Gronberg, Jeff; Hayano, Hitoshi; Honda, Yosuke; Kolomensky, Yury; Lyapin, Alexey; Malton, Stephen; May, Justin; McCormick, Douglas; Meller, Robert; Miller, David John; Orimoto, Toyoko; Ross, Marc; Slater, Mark; Smith, Steve; Smith, Tonee; Terunuma, Nobuhiro; /Fermilab /UC, Berkeley /LBL, Berkeley /Cambridge U. /Royal Holloway, U. of London /Cornell U., LNS /LLNL, Livermore /University Coll. London /SLAC /Caltech /KEK, Tsukuba

    2007-06-08

    It has been estimated that an RF cavity Beam Position Monitor (BPM) could provide a position measurement resolution of less than one nanometer. We have developed a high resolution cavity BPM and associated electronics. A triplet comprised of these BPMs was installed in the extraction line of the Accelerator Test Facility (ATF) at the High Energy Accelerator Research Organization (KEK) for testing with its ultra-low emittance beam. The three BPMs were each rigidly mounted inside an alignment frame on six variable-length struts which could be used to move the BPMs in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a robust calibration algorithm which is immune to beam jitter. To date, we have demonstrated a position resolution of 15.6 nm and a tilt resolution of 2.1 {mu}rad over a dynamic range of approximately {+-} 20 {mu}m.

  11. Performance of a High Resolution Cavity Beam Position Monitor System

    SciTech Connect

    Walston, S; Boogert, S; Chung, C; Fitsos, P; Frisch, J; Gronberg, J; Hayano, H; Honda, Y; Kolomensky, Y; Lyapin, A; Malton, S; May, J; McCormick, D; Meller, R; Miller, D; Orimoto, T; Ross, M; Slater, M; Smith, S; Smith, T; Terunuma, N; Thomson, M; Urakawa, J; Vogel, V; Ward, D; White, G

    2006-12-18

    It has been estimated that an RF cavity Beam Position Monitor (BPM) could provide a position measurement resolution of less than one nanometer. We have developed a high resolution cavity BPM and associated electronics. A triplet comprised of these BPMs was installed in the extraction line of the Accelerator Test Facility (ATF) at the High Energy Accelerator Research Organization (KEK) for testing with its ultra-low emittance beam. The three BPMs were each rigidly mounted inside an alignment frame on six variable-length struts which could be used to move the BPMs in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a robust calibration algorithm which is immune to beam jitter. To date, we have demonstrated a position resolution of 15.6 nm and a tilt resolution of 2.1 {micro}rad over a dynamic range of approximately {+-} 20 {micro}m.

  12. THz holography in reflection using a high resolution microbolometer array.

    PubMed

    Zolliker, Peter; Hack, Erwin

    2015-05-01

    We demonstrate a digital holographic setup for Terahertz imaging of surfaces in reflection. The set-up is based on a high-power continuous wave (CW) THz laser and a high-resolution (640 × 480 pixel) bolometer detector array. Wave propagation to non-parallel planes is used to reconstruct the object surface that is rotated relative to the detector plane. In addition we implement synthetic aperture methods for resolution enhancement and compare Fourier transform phase retrieval to phase stepping methods. A lateral resolution of 200 μm and a relative phase sensitivity of about 0.4 rad corresponding to a depth resolution of 6 μm are estimated from reconstructed images of two specially prepared test targets, respectively. We highlight the use of digital THz holography for surface profilometry as well as its potential for video-rate imaging.

  13. High-resolution dynamic CT scanner based on a variable-zoom XRII and a linear photodiode array

    NASA Astrophysics Data System (ADS)

    Drangova, Maria; Holdsworth, David W.; Fenster, Aaron

    1993-09-01

    We have developed a CT scanner with high temporal and spatial resolution which can be used to acquire dynamic images of objects undergoing periodic motion. Our system comprises of an x-ray image intensifier (XRII) optically coupled to a linear photo-diode array (PDA) camera. The XRII has been modified to vary electronically the magnification of the image continuously over fields-of-view (FOV) ranging between 8 and 24 cm, and thus increasing the resolution from 1.4 mm-1 to 3.8 mm-1. In this way, we can select a magnification which maximizes the image resolution for a given object.

  14. High-Resolution Surface Reconstruction from Imagery for Close Range Cultural Heritage Applications

    NASA Astrophysics Data System (ADS)

    Wenzel, K.; Abdel-Wahab, M.; Cefalu, A.; Fritsch, D.

    2012-07-01

    The recording of high resolution point clouds with sub-mm resolution is a demanding and cost intensive task, especially with current equipment like handheld laser scanners. We present an image based approached, where techniques of image matching and dense surface reconstruction are combined with a compact and affordable rig of off-the-shelf industry cameras. Such cameras provide high spatial resolution with low radiometric noise, which enables a one-shot solution and thus an efficient data acquisition while satisfying high accuracy requirements. However, the largest drawback of image based solutions is often the acquisition of surfaces with low texture where the image matching process might fail. Thus, an additional structured light projector is employed, represented here by the pseudo-random pattern projector of the Microsoft Kinect. Its strong infrared-laser projects speckles of different sizes. By using dense image matching techniques on the acquired images, a 3D point can be derived for almost each pixel. The use of multiple cameras enables the acquisition of a high resolution point cloud with high accuracy for each shot. For the proposed system up to 3.5 Mio. 3D points with sub-mm accuracy can be derived per shot. The registration of multiple shots is performed by Structure and Motion reconstruction techniques, where feature points are used to derive the camera positions and rotations automatically without initial information.

  15. Isotope specific resolution recovery image reconstruction in high resolution PET imaging

    SciTech Connect

    Kotasidis, Fotis A.; Angelis, Georgios I.; Anton-Rodriguez, Jose; Matthews, Julian C.; Reader, Andrew J.; Zaidi, Habib

    2014-05-15

    Purpose: Measuring and incorporating a scanner-specific point spread function (PSF) within image reconstruction has been shown to improve spatial resolution in PET. However, due to the short half-life of clinically used isotopes, other long-lived isotopes not used in clinical practice are used to perform the PSF measurements. As such, non-optimal PSF models that do not correspond to those needed for the data to be reconstructed are used within resolution modeling (RM) image reconstruction, usually underestimating the true PSF owing to the difference in positron range. In high resolution brain and preclinical imaging, this effect is of particular importance since the PSFs become more positron range limited and isotope-specific PSFs can help maximize the performance benefit from using resolution recovery image reconstruction algorithms. Methods: In this work, the authors used a printing technique to simultaneously measure multiple point sources on the High Resolution Research Tomograph (HRRT), and the authors demonstrated the feasibility of deriving isotope-dependent system matrices from fluorine-18 and carbon-11 point sources. Furthermore, the authors evaluated the impact of incorporating them within RM image reconstruction, using carbon-11 phantom and clinical datasets on the HRRT. Results: The results obtained using these two isotopes illustrate that even small differences in positron range can result in different PSF maps, leading to further improvements in contrast recovery when used in image reconstruction. The difference is more pronounced in the centre of the field-of-view where the full width at half maximum (FWHM) from the positron range has a larger contribution to the overall FWHM compared to the edge where the parallax error dominates the overall FWHM. Conclusions: Based on the proposed methodology, measured isotope-specific and spatially variant PSFs can be reliably derived and used for improved spatial resolution and variance performance in resolution

  16. The Goddard High Resolution Spectrograph: Instrument, goals, and science results

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Heap, S. R.; Beaver, E. A.; Boggess, A.; Carpenter, K. G.; Ebbets, D. C.; Hutchings, J. B.; Jura, M.; Leckrone, D. S.; Linsky, J. L.

    1994-01-01

    The Goddard High Resolution Spectrograph (GHRS), currently in Earth orbit on the Hubble Space Telescope (HST), operates in the wavelength range 1150-3200 A with spectral resolutions (lambda/delta lambda) of approximately 2 x 10(exp 3), 2 x 10(exp 4), and 1 x 10(exp 3). The instrument and its development from inception, its current status, the approach to operations, representative results in the major areas of the scientific goals, and prospects for the future are described.

  17. High-resolution imagery applications in the littorals

    NASA Astrophysics Data System (ADS)

    Abileah, Ronald

    2001-12-01

    We focus on three applications of high-resolution imagery in the littorals: mapping bathymetry, monitoring the health of coral reefs, and taking censuses of marine mammals. All three applications show the importance and potential benefits of higher-resolution imagery. Increased radiometric sensitivity and the simultaneous collection of panchromatic and multispectral imagery are also important. An Ikonos image of Maui is used to demonstrate these applications. We also briefly explain some important differences between multispectral remote sensing over water and land.

  18. High-resolution radiography by means of a hodoscope

    DOEpatents

    De Volpi, Alexander

    1978-01-01

    The fast neutron hodoscope, a device that produces neutron radiographs with coarse space resolution in a short time, is modified to produce neutron or gamma radiographs of relatively thick samples and with high space resolution. The modification comprises motorizing a neutron and gamma collimator to permit a controlled scanning pattern, simultaneous collection of data in a number of hodoscope channels over a period of time, and computerized image reconstruction of the data thus gathered.

  19. High spectral resolution imager for solar induced fluorescence observation

    NASA Astrophysics Data System (ADS)

    Barducci, A.; Guzzi, D.; Lastri, C.; Marcoionni, P.; Nardino, V.; Pippi, I.; Raimondi, V.; Sandri, P.

    2011-11-01

    The use of high-resolution imagers for determination of solar-induced fluorescence of natural bodies by observing the infilling of Fraunhofer lines has been frequently adopted as a tool for vegetation characterization. The option to perform those measurements from airborne platforms was addressed in the past. In-field observations gave evidence of the main requirements for an imaging spectrometer to be used for Sun-induced fluorescence measurements such as high spectral resolution and fine radiometric accuracy needed to resolve the shape of observed Fraunhofer lines with a high level of accuracy. In this paper, some solutions for the design of a high spectral resolution push-broom imaging spectrometer for Sun-induced fluorescence measurements are analysed. The main constraints for the optical design are a spectral resolution better than 0.01 nm and a wide field of view. Due to the fine instrumental spectral resolution, bidimensional focal plane arrays characterized by high quantum efficiency, low read-out noise, and high sensitivity are requested. The development of a lightweight instrument is a benefit for aerospace implementations of this technology. First results coming from laboratory measurements and optical simulations are presented and discussed taking into account their feasibility.

  20. Co-registration of high resolution MRI sub-volumes in non-human primates

    NASA Astrophysics Data System (ADS)

    Lecoeur, Jérémy; Wang, Feng; Chen, Li Min; Li, Rui; Avison, Malcom J.; Dawant, Benoit M.

    2011-03-01

    Dynamic structural and functional remodeling of the Central Nervous System occurs throughout the lifespan of the organism from the molecular to the systems level. MRI offers several advantages to observe this phenomenon: it is non-invasive and non-destructive, the contrast can be tuned to interrogate different tissue properties and imaging resolution can range from cortical columns to whole brain networks in the same session. To measure these changes reliably, functional maps generated over time with high resolution fMRI need to be registered accurately. This article presents a new method for registering automatically thin cortical MR volumes that are aligned with the functional maps. These acquisitions focus on the primary somato-sensory cortex, a region in the anterior parietal part of the brain, responsible for fine touch and proprioception. Currently, these slabs are acquired in approximately the same orientation from acquisition to acquisition and then registered by hand. Because they only cover a small portion of the cortex, their direct automatic registration is difficult. To address this issue, we propose a method relying on an intermediate image, acquired with a surface coil that covers a larger portion of the head to which the slabs can be registered. Because images acquired with surface coils suffer from severe intensity attenuation artifact, we also propose a method to register these. The results from data sets obtained with three squirrel monkeys show a registration accuracy of thirty micrometers.

  1. Towards a Global High Resolution Peatland Map in 2020

    NASA Astrophysics Data System (ADS)

    Barthelmes, Alexandra; Barthelmes, Karen-Doreen; Dommain, Rene; Margalef, Olga; Joosten, Hans

    2014-05-01

    Some 3% of land area on planet Earth (approx. 4 million km2) is covered by peatlands. About 10% (~ 0.3 % of the land area) are drained and responsible for a disproportional 5 % of the global anthropogenic CO2 emissions (Victoria et al., 2012). Additionally, peatland drainage and degradation lead to land subsidence, soil degradation, water pollution, and enhanced susceptibility to fire (Holden et al., 2004; Joosten et al., 2012). The global importance of peatlands for carbon storage and climate change mitigation has only recently been recognized in international policy - only since 2008 organic soils are subject of discussion in the UN Framework Convention on Climate Change (UNFCCC) (Joosten, 2011). In May 2013 the European Parliament decided that the global post 2020 climate agreement should include the obligation to report emissions and removals from peatland drainage and rewetting. Implementation of such program, however, necessitates the rapid availability of reliable, comprehensive, high resolution, spatially explicit data on the extent and status of peatlands. For many reporting countries this requires an innovation in peatland mapping, i.e. the better and integrative use of novel, but already available methods and technologies. We developed an approach that links various science networks, methodologies and data bases, including those of peatland/landscape ecology for understanding where and how peatlands may occur, those of remote sensing for identifying possible locations, and those of pedology (legacy soil maps) and (palaeo-)ecology for ground truthing. Such integration of old field data, specialized knowledge, and modern RS and GIS technologies enables acquiring a rapid, comprehensive, detailed and rather reliable overview, even on a continental scale. We illustrate this approach with a high resolution overview of peatland distribution, area, status and greenhouse gas fluxes for East Africa (including the Horn of Africa, the African Great Lakes region and

  2. Towards a Global High Resolution Peatland Map in 2020

    NASA Astrophysics Data System (ADS)

    Barthelmes, Alexandra; Barthelmes, Karen-Doreen; Joosten, Hans; Dommain, Rene; Margalef, Olga

    2015-04-01

    Some 3% of land area on planet Earth (approx. 4 million km2) is covered by peatlands. About 10% (~ 0.3 % of the land area) are drained and responsible for a disproportional 5 % of the global anthropogenic CO2 emissions (Victoria et al., 2012). Additionally, peatland drainage and degradation lead to land subsidence, soil degradation, water pollution, and enhanced susceptibility to fire (Holden et al., 2004; Joosten et al., 2012). The global importance of peatlands for carbon storage and climate change mitigation has currently been recognized in international policy - since 2008 organic soils are subject of discussion in the UN Framework Convention on Climate Change (UNFCCC) (Joosten, 2011). In May 2013 the European Parliament decided that the global post 2020 climate agreement should include the obligation to report emissions and removals from peatland drainage and rewetting. Implementation of such program, however, necessitates the rapid availability of reliable, comprehensive, high resolution, spatially explicit data on the extent and status of peatlands. For many reporting countries this requires an innovation in peatland mapping, i.e. the better and integrative use of novel, but already available methods and technologies. We developed an approach that links various science networks, methodologies and data bases, including those of peatland/landscape ecology for understanding where and how peatlands may occur, those of remote sensing for identifying possible locations, and those of pedology (legacy soil maps) and (palaeo-)ecology for ground truthing. Such integration of old field data, specialized knowledge, and modern RS and GIS technologies enables acquiring a rapid, comprehensive, detailed and rather reliable overview, even on a continental scale. We illustrate this approach with a high resolution overview of peatland distribution, area, status and greenhouse gas fluxes e.g. for the East African countries Rwanda, Burundi, Uganda and Zambia. Furthermore, we

  3. High-resolution dynamic atomic force microscopy in liquids with different feedback architectures

    PubMed Central

    Martínez-Martín, David; Jaafar, Miriam; Gómez-Herrero, Julio; Raman, Arvind

    2013-01-01

    Summary The recent achievement of atomic resolution with dynamic atomic force microscopy (dAFM) [Fukuma et al., Appl. Phys. Lett. 2005, 87, 034101], where quality factors of the oscillating probe are inherently low, challenges some accepted beliefs concerning sensitivity and resolution in dAFM imaging modes. Through analysis and experiment we study the performance metrics for high-resolution imaging with dAFM in liquid media with amplitude modulation (AM), frequency modulation (FM) and drive-amplitude modulation (DAM) imaging modes. We find that while the quality factors of dAFM probes may deviate by several orders of magnitude between vacuum and liquid media, their sensitivity to tip–sample forces can be remarkable similar. Furthermore, the reduction in noncontact forces and quality factors in liquids diminishes the role of feedback control in achieving high-resolution images. The theoretical findings are supported by atomic-resolution images of mica in water acquired with AM, FM and DAM under similar operating conditions. PMID:23503468

  4. Extension of least squares spectral resolution algorithm to high-resolution lipidomics data.

    PubMed

    Zeng, Ying-Xu; Mjøs, Svein Are; David, Fabrice P A; Schmid, Adrien W

    2016-03-31

    Lipidomics, which focuses on the global study of molecular lipids in biological systems, has been driven tremendously by technical advances in mass spectrometry (MS) instrumentation, particularly high-resolution MS. This requires powerful computational tools that handle the high-throughput lipidomics data analysis. To address this issue, a novel computational tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. The algorithm features the customized generation of a lipid compound library and mass spectral library, which covers the major lipid classes such as glycerolipids, glycerophospholipids and sphingolipids. Next, the algorithm performs least squares resolution of spectra and chromatograms based on the theoretical isotope distribution of molecular ions, which enables automated identification and quantification of molecular lipid species. Currently, this methodology supports analysis of both high and low resolution MS as well as liquid chromatography-MS (LC-MS) lipidomics data. The flexibility of the methodology allows it to be expanded to support more lipid classes and more data interpretation functions, making it a promising tool in lipidomic data analysis.

  5. Estimation of the distribution of Tabebuia guayacan (Bignoniaceae) using high-resolution remote sensing imagery.

    PubMed

    Sánchez-Azofeifa, Arturo; Rivard, Benoit; Wright, Joseph; Feng, Ji-Lu; Li, Peijun; Chong, Mei Mei; Bohlman, Stephanie A

    2011-01-01

    Species identification and characterization in tropical environments is an emerging field in tropical remote sensing. Significant efforts are currently aimed at the detection of tree species, of levels of forest successional stages, and the extent of liana occurrence at the top of canopies. In this paper we describe our use of high resolution imagery from the Quickbird Satellite to estimate the flowering population of Tabebuia guayacan trees at Barro Colorado Island (BCI), in Panama. The imagery was acquired on 29 April 2002 and 21 March 2004. Spectral Angle Mapping via a One-Class Support Vector machine was used to detect the presence of 422 and 557 flowering tress in the April 2002 and March 2004 imagery. Of these, 273 flowering trees are common to both dates. This study presents a new perspective on the effectiveness of high resolution remote sensing for monitoring a phenological response and its use as a tool for potential conservation and management of natural resources in tropical environments.

  6. High resolution multidetector CT aided tissue analysis and quantification of lung fibrosis

    NASA Astrophysics Data System (ADS)

    Zavaletta, Vanessa A.; Karwoski, Ronald A.; Bartholmai, Brian; Robb, Richard A.

    2006-03-01

    Idiopathic pulmonary fibrosis (IPF, also known as Idiopathic Usual Interstitial Pneumontis, pathologically) is a progressive diffuse lung disease which has a median survival rate of less than four years with a prevalence of 15-20/100,000 in the United States. Global function changes are measured by pulmonary function tests and the diagnosis and extent of pulmonary structural changes are typically assessed by acquiring two-dimensional high resolution CT (HRCT) images. The acquisition and analysis of volumetric high resolution Multi-Detector CT (MDCT) images with nearly isotropic pixels offers the potential to measure both lung function and structure. This paper presents a new approach to three dimensional lung image analysis and classification of normal and abnormal structures in lungs with IPF.

  7. On the Utility of High-Resolution InSAR Data for Geodynamic Applications

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Amelung, F.

    2014-12-01

    High-spatial and high-temporal resolution InSAR data acquired by the TerraSAR-X and Cosmo-Skymed satellites is becoming increasingly available for geodynamic applications, including volcanic crises, the arctic ice sheets and land subsidence problems. The advantage of these second-generation SAR systems is that processes can be resolved that were not visible by the low-resolution first-generation systems, such as pre-eruptive deformation of a volcanic dome and uplift or subsidence of the bedrock in response to a glacial surge. The drawback is the limited temporal coherence because these satellites operate at X-Band, which makes them suitable only for particular environments. In this poster we present a variety of applications. Our purpose is to better define the potential of these systems for geodynamic applications.

  8. High-resolution, lensless endoscope based on digital scanning through a multimode optical fiber

    PubMed Central

    Papadopoulos, Ioannis N.; Farahi, Salma; Moser, Christophe; Psaltis, Demetri

    2013-01-01

    We propose and experimentally demonstrate an ultra-thin rigid endoscope (450 μm diameter) based on a passive multimode optical fiber. We use digital phase conjugation to overcome the modal scrambling of the fiber to tightly focus and scan the laser light at its distal end. By exploiting the maximum number of modes available, sub-micron resolution, high quality fluorescence images of neuronal cells were acquired. The imaging system is evaluated in terms of fluorescence collection efficiency, resolution and field of view. The small diameter of the proposed endoscope, along with its high quality images offer an opportunity for minimally invasive medical endoscopic imaging and diagnosis based on cellular phenotype via direct tissue penetration. PMID:23411747

  9. Distinguishing and quantification of the human visual pathways using high-spatial-resolution diffusion tensor tractography.

    PubMed

    Kamali, Arash; Hasan, Khader M; Adapa, Pavani; Razmandi, Azadeh; Keser, Zafer; Lincoln, John; Kramer, Larry A

    2014-09-01

    Quantification of the living human visual system using MRI methods has been challenging, but several applications demand a reliable and time-efficient data acquisition protocol. In this study, we demonstrate the utility of high-spatial-resolution diffusion tensor fiber tractography (DTT) in reconstructing and quantifying the human visual pathways. Five healthy males, age range 24-37years, were studied after approval of the institutional review board (IRB) at The University of Texas Health Science Center at Houston. We acquired diffusion tensor imaging (DTI) data with 1-mm slice thickness on a 3.0-Tesla clinical MRI scanner and analyzed the data using DTT with the fiber assignment by continuous tractography (FACT) algorithm. By utilizing the high-spatial-resolution DTI protocol with FACT algorithm, we were able to reconstruct and quantify bilateral optic pathways including the optic chiasm, optic tract, optic radiations free of contamination from neighboring white matter tracts.

  10. Distinguishing and quantification of the human visual pathways using high spatial resolution diffusion tensor tractography

    PubMed Central

    Kamali, Arash; Hasan, Khader M.; Adapa, Pavani; Razmandi, Azadeh; Keser, Zafer; Lincoln, John; Kramer, Larry A.

    2014-01-01

    Quantification of the living human visual system using MRI methods has been challenging, but several applications demand a reliable and time-efficient data acquisition protocol. In this study, we demonstrate the utility of high spatial resolution diffusion tensor fiber tractography (DTT) in reconstructing and quantifying the human visual pathways. Five healthy males, age range 24–37 years, were studied after approval of the Institutional Review Board (IRB) at The University of Texas Health Science Center at Houston. We acquired diffusion tensor imaging (DTI) data with 1-mm slice thickness on a 3.0 Tesla clinical MRI scanner and analyzed the data using DTT with the fiber assignment by continuous tractography (FACT) algorithm. By utilizing the high spatial resolution DTI protocol with FACT algorithm, we were able to reconstruct and quantify bilateral optic pathways including the optic chiasm, optic tract, optic radiations free of contamination from neighboring white matter tracts. PMID:24856625

  11. Cirrus cloud characteristics derived from volume imaging lidar, high spectral resolution lidar, HIS radiometer, and satellite

    NASA Technical Reports Server (NTRS)

    Grund, Christian J.; Ackerman, Steven A.; Eloranta, Edwin W.; Knutsen, Robert O.; Revercomb, Henry E.; Smith, William L.; Wylie, Donald P.

    1990-01-01

    Preliminary measurement results are presented from the Cirrus Remote Sensing Pilot Experiment which used a unique suite of instruments to simultaneously retrieve cirrus cloud visible and IR optical properties, while addressing the disparities between satellite volume averages and local point measurements. The experiment employed a ground-based high resolution interferometer sounder (HIS) and a second Fourier transform spectrometer to measure the spectral radiance in the 4-20 micron band, a correlated high spectral resolution lidar, a volume imaging lidar, a CLASS radiosonde system, the Scripps Whole Sky Imager, and multispectral VAS, HIRS, and AVHRR satellite data from polar orbiting and geostationary satellites. Data acquired during the month long experiment included continuous daytime monitoring with the Whole Sky Imager.

  12. Wide swath and high resolution optical imaging satellite of Japan

    NASA Astrophysics Data System (ADS)

    Katayama, Haruyoshi; Kato, Eri; Imai, Hiroko; Sagisaka, Masakazu

    2016-05-01

    The "Advanced optical satellite" (tentative name) is a follow-on mission from ALOS. Mission objectives of the advanced optical satellite is to build upon the existing advanced techniques for global land observation using optical sensors, as well as to promote data utilization for social needs. Wide swath and high resolution optical imager onboard the advanced optical satellite will extend the capabilities of earlier ALOS missions. The optical imager will be able to collect high-resolution (< 1 m) and wide-swath (70 km) images with high geo-location accuracy. This paper introduces a conceptual design of the advanced optical satellite.

  13. High resolution BPMS with integrated gain correction system

    SciTech Connect

    Wendt, M.; Briegel, C.; Eddy, N.; Fellenz, B.; Gianfelice, E.; Prieto, P.; Rechenmacher, R.; Voy, D.; Terunuma, N.; Urakawa, J.; /KEK, Tsukuba

    2009-08-01

    High resolution beam position monitors (BPM) are an essential tool to achieve and reproduce a low vertical beam emittance at the KEK Accelerator Test Facility (ATF) damping ring. The ATF damping ring (DR) BPMs are currently upgraded with new high resolution read-out electronics. Based on analog and digital down-conversion techniques, the upgrade includes an automatic gain calibration system to correct for slow drift effects and ensure high reproducible beam position readings. The concept and its technical realization, as well as preliminary results of beam studies are presented.

  14. Design and implementation of spaceborne high resolution infrared touch screen

    NASA Astrophysics Data System (ADS)

    Li, Tai-guo; Li, Wen-xin; Dong, Yi-peng; Ma, Wen; Xia, Jia-gao

    2015-10-01

    For the consideration of the special application environment of the electronic products used in aerospace and to further more improve the human-computer interaction of the manned aerospace area. The research is based on the design and implementation way of the high resolution spaceborne infrared touch screen on the basis of FPGA and DSP frame structure. Beside the introduction of the whole structure for the high resolution spaceborne infrared touch screen system, this essay also gives the detail information about design of hardware for the high resolution spaceborne infrared touch screen system, FPGA design, GUI design and DSP algorithm design based on Lagrange interpolation. What is more, the easy makes a comprehensive research of the reliability design for the high resolution spaceborne infrared touch screen for the special purpose of it. Besides, the system test is done after installation of spaceborne infrared touch screen. The test result shows that the system is simple and reliable enough, which has a stable running environment and high resolution, which certainly can meet the special requirement of the manned aerospace instrument products.

  15. Large-field high-resolution mosaic movies

    NASA Astrophysics Data System (ADS)

    Hammerschlag, Robert H.; Sliepen, Guus; Bettonvil, Felix C. M.; Jägers, Aswin P. L.; Sütterlin, Peter; Lin, Yong; Martin, Sara F.; Panasenco, Olga; Romashets, Eugene P.

    2013-08-01

    Movies with fields-of-view larger than normal, for high-resolution telescopes, will give a better understanding of processes on the Sun such as filament and active region developments and their possible interactions. New active regions can serve as an igniter of the eruption of a nearby filament. A method to create a large field-of-view is to join several fields-of-view into a mosaic. Fields are imaged quickly, one after another, using fast telescope-pointing. Such a pointing cycle has been automated at the Dutch open telescope (DOT), a high-resolution solar telescope located on the Canary Island La Palma. The number and positions of the subfields are calculated automatically and represented by an array of bright points in the guider image which indicates the subfield centers inside the drawn rectangle of the total field on the computer screen with the whole-sun image. Automatic production of flats is also programmed. For the first time, mosaic movies were programmed from stored information on automated telescope motions. The mosaic movies show larger regions of the solar disk in high resolution and fill a gap between available whole-sun images with limited spatial resolution of synoptic telescopes including space instruments and small-field high-cadence movies of high-resolution solar telescopes.

  16. Evacuee Compliance Behavior Analysis using High Resolution Demographic Information

    SciTech Connect

    Lu, Wei; Han, Lee; Liu, Cheng; Tuttle, Mark A; Bhaduri, Budhendra L

    2014-01-01

    The purpose of this study is to examine whether evacuee compliance behavior with route assignments from different resolutions of demographic data would impact the evacuation performance. Most existing evacuation strategies assume that travelers will follow evacuation instructions, while in reality a certain percent of evacuees do not comply with prescribed instructions. In this paper, a comparison study of evacuation assignment based on Traffic Analysis Zones (TAZ) and high resolution LandScan USA Population Cells (LPC) were conducted for the detailed road network representing Alexandria, Virginia. A revised platform for evacuation modeling built on high resolution demographic data and activity-based microscopic traffic simulation is proposed. The results indicate that evacuee compliance behavior affects evacuation efficiency with traditional TAZ assignment, but it does not significantly compromise the efficiency with high resolution LPC assignment. The TAZ assignment also underestimates the real travel time during evacuation, especially for high compliance simulations. This suggests that conventional evacuation studies based on TAZ assignment might not be effective at providing efficient guidance to evacuees. From the high resolution data perspective, traveler compliance behavior is an important factor but it does not impact the system performance significantly. The highlight of evacuee compliance behavior analysis should be emphasized on individual evacuee level route/shelter assignments, rather than the whole system performance.

  17. Lynx: A High-Resolution Synthetic Aperture Radar

    SciTech Connect

    Doerry, A.W.; Hensley, W.H.; Pace, F.; Stence, J.; Tsunoda, S.I.; Walker, B.C.; Woodring, M.

    1999-03-08

    Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.

  18. Validation of High-resolution Climate Simulations over Northern Europe.

    NASA Astrophysics Data System (ADS)

    Muna, R. A.

    2005-12-01

    Two AMIP2-type (Gates 1992) experiments have been performed with climate versions of ARPEGE/IFS model examine for North Atlantic North Europe, and Norwegian region and analyzed the effect of increasing resolution on the simulated biases. The ECMWF reanalysis or ERA-15 has been used to validate the simulations. Each of the simulations is an integration of the period 1979 to 1996. The global simulations used observed monthly mean sea surface temperatures (SST) as lower boundary condition. All aspects but the horizontal resolutions are similar in the two simulations. The first simulation has a uniform horizontal resolution of T63L. The second one has a variable resolution (T106Lc3) with the highest resolution in the Norwegian Sea. Both simulations have 31 vertical layers in the same locations. For each simulation the results were divided into two seasons: winter (DJF) and summer (JJA). The parameters investigated were mean sea level pressure, geopotential and temperature at 850 hPa and 500 hPa. To find out the causes of temperature bias during summer, latent and sensible heat flux, total cloud cover and total precipitation were analyzed. The high-resolution simulation exhibits more or less realistic climate over Nordic, Artic and European region. The overall performance of the simulations shows improvements of generally all fields investigated with increasing resolution over the target area both in winter (DJF) and summer (JJA).

  19. High-resolution planetary imaging via spotlight-mode synthetic aperture radar.

    PubMed

    Webb, J H; Munson, D R; Stacy, N S

    1998-01-01

    We consider the application of a spotlight-mode synthetic aperture radar (SAR) imaging technique to the problem of high-resolution lunar imaging and other related radar astronomy problems. This approach offers improved image quality, compared with conventional processing, at the expense of slightly increased computational effort. Results of the processing of lunar data acquired with the 12.6 cm wavelength radar system at Arecibo Observatory are presented, and compared with the best available published result, by Stacy (1993), which uses focusing techniques from stripmap SAR.

  20. High-Resolution Daily Flood Extent Depiction from Microwave Remote Sensing: Global Results

    NASA Astrophysics Data System (ADS)

    Galantowicz, J. F.

    2015-12-01

    The need for frequent, accurate, high-resolution characterization of the temporal and spatial progression of flood hazards is evident, but has been beyond the capabilities of remote sensing methods. The surface is too often obscured by cloud cover for visual and infrared sensors and observations from radar sensors are too infrequent to create consistent historical databases or for monitoring current conditions. Passive microwave sensors, such as SSM/I, AMSR-E, and AMSR-2, acquire useful data during clear and cloudy conditions, have revisit periods of up to twice daily, and provide a continuous record of data from 1987 to the present. In this presentation, we will describe results from a flood mapping system capable of producing high-resolution (100-m) flood extent depictions from lower resolution (10-40-km) microwave data. The system uses the strong sensitivity of microwave data to surface water extent combined with land surface and atmospheric data to derive daily flooded fraction estimates globally on a sensor footprint basis. The system downscales flooded fraction to make a high-resolution Boolean flood extent depiction that is both spatially continuous and consistent with the lower resolution data (see Figure). The downscaling step is based on a relative floodability index derived from higher resolution topographic and hydrological data and processed to represent the minimum total water fraction threshold above which each grid point is expected to be flooded given microwave-derived water fraction inputs. We have completed daily, 100-m resolution flood maps for Africa for the 9.3-year AMSR-E period and will soon complete global flood maps fo the same period. We will present animations of daily flood extents during major events and discuss: validation of the flood maps against imagery derived from MODIS and Landsat data; analyses of minimum detectable flood size; statistical analyses of flooding over time; applications for this novel historical dataset; and

  1. Systematic High-Resolution (30 meter) Inventory of Global Lakes: Pan-Arctic and Beyond

    NASA Astrophysics Data System (ADS)

    Sheng, Y.; Wang, J.; Smith, L. C.; Lyons, E. A.; Te, G.; Woods, J.; Garibay, D.; Knox, B.

    2014-12-01

    [Abstract] Lakes play a crucial role in the global water cycle and balance, are sensitive to global warming, and are vital for human water supply. There clearly is a pressing need to understand temporal and spatial variations in lake water storage globally, especially in the lake-rich Arctic/Sub-Arctic regions. An accurate systematic lake inventory, however, is unavailable at global scales. Owing to its broad spatial coverage and repeat-pass monitoring capability, satellite remote sensing is the only feasible approach to inventory global lake dynamics. Global lake mapping at high resolutions is a rather challenging task. Since lakes are abundant in small-size classes and their seasonality varies from region to region, a huge number of high-resolution satellite images need to be acquired in "appropriate" seasons. The appropriate seasons refer to the period in a typical year when lakes are relatively stable, and are determined spatially using precipitation and temperature datasets. Thousands of cloud-free Landsat images at 30 m resolution have been acquired during lake-stable seasons. Satellite lake mapping succeeds at different levels from place to place and from season to season. A set of highly replicable automated lake mapping methods and tools have been developed to tackle various situations across the entire Earth and to handle such a large volume of satellite data. The current goal is to produce a circa 2000 high-resolution global lake database in a systematic way. Millions of lakes larger than 0.5 ha have been inventoried. The product is currently examined in an intensive quality control and quality assurance process. Over six million lakes in pan-Arctic (45 deg N and above) are captured in the database and have been validated for release.

  2. Estimating evapotranspiration of riparian vegetation using high resolution multispectral, thermal infrared and lidar data

    NASA Astrophysics Data System (ADS)

    Neale, Christopher M. U.; Geli, Hatim; Taghvaeian, Saleh; Masih, Ashish; Pack, Robert T.; Simms, Ronald D.; Baker, Michael; Milliken, Jeff A.; O'Meara, Scott; Witherall, Amy J.

    2011-11-01

    High resolution airborne multispectral and thermal infrared imagery was acquired over the Mojave River, California with the Utah State University airborne remote sensing system integrated with the LASSI imaging Lidar also built and operated at USU. The data were acquired in pre-established mapping blocks over a 2 day period covering approximately 144 Km of the Mojave River floodplain and riparian zone, approximately 1500 meters in width. The multispectral imagery (green, red and near-infrared bands) was ortho-rectified using the Lidar point cloud data through a direct geo-referencing technique. Thermal Infrared imagery was rectified to the multispectral ortho-mosaics. The lidar point cloud data was classified to separate ground surface returns from vegetation returns as well as structures such as buildings, bridges etc. One-meter DEM's were produced from the surface returns along with vegetation canopy height also at 1-meter grids. Two surface energy balance models that use remote sensing inputs were applied to the high resolution imagery, namely the SEBAL and the Two Source Model. The model parameterizations were slightly modified to accept high resolution imagery (1-meter) as well as the lidar-based vegetation height product, which was used to estimate the aerodynamic roughness length. Both models produced very similar results in terms of latent heat fluxes (LE). Instantaneous LE values were extrapolated to daily evapotranspiration rates (ET) using the reference ET fraction, with data obtained from a local weather station. Seasonal rates were obtained by extrapolating the reference ET fraction according to the seasonal growth habits of the different species. Vegetation species distribution and area were obtained from classification of the multispectral imagery. Results indicate that cottonwood and salt cedar (tamarisk) had the highest evapotranspiration rates followed by mesophytes, arundo, mesquite and desert shrubs. This research showed that high-resolution

  3. High spectral resolution measurements for the ARM Program

    SciTech Connect

    Revercomb, H.E.

    1992-05-22

    This report focuses on the design and fabrication of high spectral resolution FTIR (Fourier Transform Infrared) instrumentation for the CART sites of the Atmospheric Radiation Measurement (ARM) Program. The ultimate objective of this grant is to develop three different types of instruments, named the AERI, AERI-X, and SORT. The Atmospheric Emitted Radiance Interferometer (AERI) is the simplest. It will be available for early deployment at the first ARM site and will be deployable at several locations in the extended network to give horizontal coverage. The AERI will be an 0.5 cm{sup {minus}1} resolution instrument, which measures accurately calibrated radiance spectra for radiation studies and for remote sensing of atmospheric state variables. The AERI-X and the SORTI are higher spectral resolution instruments for obtaining the highest practical resolution for spectroscopy at the ARM central sites. The AERI-X, like the AERI will measure atmospheric emitted radiance, but with resolutions as high as 0.1 cm{sup {minus}1}. The Solar Radiance Transmission Interferometer will measure the total transmission of the atmosphere by tracking the sun through changes in atmospheric air mass. The large solar signal makes it practical for this instrument to offer the ultimate in spectral resolution, about 0.002 cm{sup {minus}1}.

  4. Achieving High Resolution Timer Events in Virtualized Environment

    PubMed Central

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs—Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  5. Achieving High Resolution Timer Events in Virtualized Environment.

    PubMed

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  6. Classical broadcasting is possible with arbitrarily high fidelity and resolution.

    PubMed

    Walker, Thomas A; Braunstein, Samuel L

    2007-02-23

    We quantify the resolution with which any probability distribution may be distinguished from a displaced copy of itself in terms of a characteristic width. This width, which we call the resolution, is well defined for any normalizable probability distribution. We use this concept to study the broadcasting of classical probability distributions. Ideal classical broadcasting creates two (or more) output random variables each of which has the same distribution as the input random variable. We show that the universal broadcasting of probability distributions may be achieved with arbitrarily high fidelities for any finite resolution. By restricting probability distributions to any finite resolution we have therefore shown that the classical limit of quantum broadcasting is consistent with the actual classical case.

  7. EFTEM spectrum imaging at high-energy resolution.

    PubMed

    Schaffer, Bernhard; Kothleitner, Gerald; Grogger, Werner

    2006-01-01

    This paper deals with the application of high-energy resolution EFTEM image series and the corrections needed for reliable data interpretation. The detail of spectral information gained from an image series is largely determined by the intrinsic energy resolution. In this work we show that energy resolution values of as low as 0.8 eV in spectra extracted from EFTEM image series can be obtained with a small energy-selecting slit. At this resolution level aberrations of the energy filter, in particular the non-isochromaticity, can no longer be neglected. We show that the four most prominent factors for EFTEM image series data correction--spatial drift, non-isochromaticity, energy drift and image distortion--must not be treated independently but have to be corrected in unison. We present an efficient algorithm for this correction, and demonstrate the applied correction for the case of a GaN/AlN multilayer sample. PMID:16872748

  8. High-resolution DEM Effects on Geophysical Flow Models

    NASA Astrophysics Data System (ADS)

    Williams, M. R.; Bursik, M. I.; Stefanescu, R. E. R.; Patra, A. K.

    2014-12-01

    Geophysical mass flow models are numerical models that approximate pyroclastic flow events and can be used to assess the volcanic hazards certain areas may face. One such model, TITAN2D, approximates granular-flow physics based on a depth-averaged analytical model using inputs of basal and internal friction, material volume at a coordinate point, and a GIS in the form of a digital elevation model (DEM). The volume of modeled material propagates over the DEM in a way that is governed by the slope and curvature of the DEM surface and the basal and internal friction angles. Results from TITAN2D are highly dependent upon the inputs to the model. Here we focus on a single input: the DEM, which can vary in resolution. High resolution DEMs are advantageous in that they contain more surface details than lower-resolution models, presumably allowing modeled flows to propagate in a way more true to the real surface. However, very high resolution DEMs can create undesirable artifacts in the slope and curvature that corrupt flow calculations. With high-resolution DEMs becoming more widely available and preferable for use, determining the point at which high resolution data is less advantageous compared to lower resolution data becomes important. We find that in cases of high resolution, integer-valued DEMs, very high-resolution is detrimental to good model outputs when moderate-to-low (<10-15°) slope angles are involved. At these slope angles, multiple adjacent DEM cell elevation values are equal due to the need for the DEM to approximate the low slope with a limited set of integer values for elevation. The first derivative of the elevation surface thus becomes zero. In these cases, flow propagation is inhibited by these spurious zero-slope conditions. Here we present evidence for this "terracing effect" from 1) a mathematically defined simulated elevation model, to demonstrate the terracing effects of integer valued data, and 2) a real-world DEM where terracing must be

  9. 3D high spectral and spatial resolution imaging of ex vivo mouse brain

    SciTech Connect

    Foxley, Sean Karczmar, Gregory S.; Domowicz, Miriam; Schwartz, Nancy

    2015-03-15

    Purpose: Widely used MRI methods show brain morphology both in vivo and ex vivo at very high resolution. Many of these methods (e.g., T{sub 2}{sup *}-weighted imaging, phase-sensitive imaging, or susceptibility-weighted imaging) are sensitive to local magnetic susceptibility gradients produced by subtle variations in tissue composition. However, the spectral resolution of commonly used methods is limited to maintain reasonable run-time combined with very high spatial resolution. Here, the authors report on data acquisition at increased spectral resolution, with 3-dimensional high spectral and spatial resolution MRI, in order to analyze subtle variations in water proton resonance frequency and lineshape that reflect local anatomy. The resulting information compliments previous studies based on T{sub 2}{sup *} and resonance frequency. Methods: The proton free induction decay was sampled at high resolution and Fourier transformed to produce a high-resolution water spectrum for each image voxel in a 3D volume. Data were acquired using a multigradient echo pulse sequence (i.e., echo-planar spectroscopic imaging) with a spatial resolution of 50 × 50 × 70 μm{sup 3} and spectral resolution of 3.5 Hz. Data were analyzed in the spectral domain, and images were produced from the various Fourier components of the water resonance. This allowed precise measurement of local variations in water resonance frequency and lineshape, at the expense of significantly increased run time (16–24 h). Results: High contrast T{sub 2}{sup *}-weighted images were produced from the peak of the water resonance (peak height image), revealing a high degree of anatomical detail, specifically in the hippocampus and cerebellum. In images produced from Fourier components of the water resonance at −7.0 Hz from the peak, the contrast between deep white matter tracts and the surrounding tissue is the reverse of the contrast in water peak height images. This indicates the presence of a shoulder in

  10. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    SciTech Connect

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  11. The theory and practice of high resolution scanning electron microscopy

    SciTech Connect

    Joy, D.C. Oak Ridge National Lab., TN )

    1990-01-01

    Recent advances in instrumentation have produced the first commercial examples of what can justifiably be called High Resolution Scanning Electron Microscopes. The key components of such instruments are a cold field emission gun, a small-gap immersion probe-forming lens, and a clean dry-pumped vacuum. The performance of these microscopes is characterized by several major features including a spatial resolution, in secondary electron mode on solid specimens, which can exceed 1nm on a routine basis; an incident probe current density of the order of 10{sup 6} amps/cm{sup 2}; and the ability to maintain these levels of performance over an accelerating voltage range of from 1 to 30keV. This combination of high resolution, high probe current, low contamination and flexible electron-optical conditions provides many new opportunitites for the application of the SEM to materials science, physics, and the life sciences. 27 refs., 14 figs.

  12. High spatial resolution measurements of ram accelerator gas dynamic phenomena

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Data obtained by using a special highly instrumented section of tube has allowed the recording of gas dynamic phenomena with a spatial resolution on the order of one tenth the projectile length. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) are presented and reveal the 3D character of the flowfield induced by projectile fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, 3D CFD code.

  13. A prototype of very high resolution small animal PET scanner using silicon pad detectors

    PubMed Central

    Park, Sang-June; Leslie Rogers, W.; Huh, Sam; Kagan, Harris; Honscheid, Klaus; Burdette, Don; Chesi, Enrico; Lacasta, Carlos; Llosa, Gabriela; Mikuz, Marko; Studen, Andrej; Weilhammer, Peter; Clinthorne, Neal H.

    2007-01-01

    A very high resolution small animal positron emission tomograph (PET) which can achieve sub-millimeter spatial resolution is being developed using silicon pad detectors. The prototype PET for a single slice instrument consists of two 1 mm thick silicon pad detectors, each containing a 32 × 16 array of 1.4 mm × 1.4 mm pads read out with four VATAGP3 chips which have 128 channels low-noise self triggering ASIC in each chip, coincidence units, a source turntable and tungsten slice collimator. The silicon detectors were located edgewise on opposite sides of a 4 cm field-of-view to maximize efficiency. Energy resolution is dominated by electronic noise, which is 0.98% (1.38 keV) FWHM at 140.5 keV. Coincidence timing resolution is 82.1 ns FWHM and coincidence efficiency was measured to be 1.04 × 10-3 % from two silicon detectors with annihilation photons of 18F source Image data were acquired and reconstructed using conventional 2-D filtered-back projection (FBP) and a maximum likelihood expectation maximization (ML-EM) method. Image resolution of approximately 1.45 mm FWHM is obtained from 1-D profile of 1.1 mm diameter 18F line source image. Even better resolution can be obtained with smaller detector element sizes. While many challenges remain in scaling up the instrument to useful efficiency including densely packed detectors and significantly improved timing resolution, performance of the test setup in terms of easily achieving submillimeter resolution is compelling. PMID:18084629

  14. Uncoupling High Light Responses from Singlet Oxygen Retrograde Signaling and Spatial-Temporal Systemic Acquired Acclimation.

    PubMed

    Carmody, Melanie; Crisp, Peter A; d'Alessandro, Stefano; Ganguly, Diep; Gordon, Matthew; Havaux, Michel; Albrecht-Borth, Verónica; Pogson, Barry J

    2016-07-01

    Distinct ROS signaling pathways initiated by singlet oxygen ((1)O2) or superoxide and hydrogen peroxide have been attributed to either cell death or acclimation, respectively. Recent studies have revealed that more complex antagonistic and synergistic relationships exist within and between these pathways. As specific chloroplastic ROS signals are difficult to study, rapid systemic signaling experiments using localized high light (HL) stress or ROS treatments were used in this study to uncouple signals required for direct HL and ROS perception and distal systemic acquired acclimation (SAA). A qPCR approach was chosen to determine local perception and distal signal reception. Analysis of a thylakoidal ascorbate peroxidase mutant (tapx), the (1)O2-retrograde signaling double mutant (ex1/ex2), and an apoplastic signaling double mutant (rbohD/F) revealed that tAPX and EXECUTER 1 are required for both HL and systemic acclimation stress perception. Apoplastic membrane-localized RBOHs were required for systemic spread of the signal but not for local signal induction in directly stressed tissues. Endogenous ROS treatments revealed a very strong systemic response induced by a localized 1 h induction of (1)O2 using the conditional flu mutant. A qPCR time course of (1)O2 induced systemic marker genes in directly and indirectly connected leaves revealed a direct vascular connection component of both immediate and longer term SAA signaling responses. These results reveal the importance of an EXECUTER-dependent (1)O2 retrograde signal for both local and long distance RBOH-dependent acclimation signaling that is distinct from other HL signaling pathways, and that direct vascular connections have a role in spatial-temporal SAA induction. PMID:27288360

  15. A high-throughput de novo sequencing approach for shotgun proteomics using high-resolution tandem mass spectrometry

    SciTech Connect

    Pan, Chongle; Park, Byung H; McDonald, W Hayes; Banfield, Jillian F.; Verberkmoes, Nathan C; Hettich, Robert {Bob} L; Samatova, Nagiza F

    2010-01-01

    High-resolution tandem mass spectra can now readily be acquired with hybrid instruments, such as LTQ-Orbitrap and LTQ-FT, in high-throughput shotgun proteomics workflows. In this study, a new de novo sequencing algorithm, Vonode, has been developed specifically for such high-resolution tandem mass spectra. To fully exploit the high mass accuracy, sparse noise, and low background of these spectra, a unique scoring system is used to evaluate sequence tags based mainly on mass accuracy information of fragment ions. Consensus sequence tags were inferred for 11,422 spectra with an average peptide length of 5.5 residues from a total of 40,297 input spectra acquired in a 24-hour proteomics measurement of Rhodopseudomonas palustris. The accuracy of inferred consensus sequence tags was 84%. The performance of Vonode was shown to be superior to the PepNovo v2.0 algorithm, especially in term of the number of de novo sequenced spectra.

  16. High-resolution seismic studies applied to injected geothermal fluids

    SciTech Connect

    Smith, A.T.; Kasameyer, P.

    1985-01-01

    The application of high-resolution microseismicity studies to the problem of monitoring injected fluids is one component of the Geothermal Injection Monitoring Project at LLNL. The evaluation of microseismicity includes the development of field techniques, and the acquisition and processing of events during the initial development of a geothermal field. To achieve a specific detection threshold and location precision, design criteria are presented for seismic networks. An analysis of a small swarm near Mammoth Lakes, California, demonstrates these relationships and the usefulness of high-resolution seismic studies. A small network is currently monitoring the Mammoth-Pacific geothermal power plant at Casa Diablo as it begins production.

  17. High resolution collimator system for X-ray detector

    DOEpatents

    Eberhard, Jeffrey W.; Cain, Dallas E.

    1987-01-01

    High resolution in an X-ray computerized tomography (CT) inspection system is achieved by using a collimator/detector combination to limit the beam width of the X-ray beam incident on a detector element to the desired resolution width. In a detector such as a high pressure Xenon detector array, a narrow tapered collimator is provided above a wide detector element. The collimator slits have any desired width, as small as a few mils at the top, the slit width is easily controlled, and they are fabricated on standard machines. The slit length determines the slice thickness of the CT image.

  18. Theoretical Problems in High Resolution Solar Physics, 2

    NASA Technical Reports Server (NTRS)

    Athay, G. (Editor); Spicer, D. S. (Editor)

    1987-01-01

    The Science Working Group for the High Resolution Solar Observatory (HRSO) laid plans beginning in 1984 for a series of workshops designed to stimulate a broadbased input from the scientific community to the HRSO mission. These workshops have the dual objectives of encouraging an early start on the difficult theoretical problems in radiative transfer, magnetohydrodynamics, and plasma physics that will be posed by the HRSO data, and maintaining current discussions of results in high resolution solar studies. This workshop was the second in the series. The workshop format presented invited review papers during the formal sessions and contributed poster papers for discussions during open periods. Both are presented.

  19. High Resolution EUV & FUV Spectroscopy of DA White Dwarfs

    NASA Astrophysics Data System (ADS)

    Barstow, M. A.; Good, S. A.; Bannister, N. P.; Burleigh, M. R.; Holberg, J. B.; Bruhweiler, F. C.; Napiwotzki, R.; Cruddace, R. G.; Kowalski, M. P.

    We report on recent results from a high-resolution spectroscopic survey of hot DA white dwarfs, based on IUE, FUSE and HST observations. For the first time, we address the measurement of element abundances in a completely objective manner with a spectroscopic model fitting technique, which allows us to consider formally the limits that can be placed on abundances in stars where no heavy elements are detected. We also include our latest analysis of the high resolution EUV spectrum of G191-B2B recorded by J-PEX.

  20. Design and test of a High-Resolution EUV Spectroheliometer

    NASA Technical Reports Server (NTRS)

    Berger, Thomas E.; Timothy, J. G.; Walker, Arthur B. C., Jr.; Kirby, Helen; Morgan, Jeffrey S.; Jain, Surendra K.; Saxena, Ajay K.; Bhattacharyya, Jagadish C.; Huber, Martin C. E.; Tondello, Giuseppe

    1992-01-01

    The HiRES High-Resolution EUV Spectroheliometer is a sounding rocket instrument yielding very high spatial, spectral, and temporal resolution images of the solar outer atmosphere, on the basis of a 45-cm Gregorian telescope feeding a normal-incidence stigmatic EUV spectrometer with imaging multianode microchannel-array detector system, as well as an IR spectrometer with imaging CCD detector system. Attention is given to the expected performance of this system, including the effects of vibrational misalignments due to the sounding rocket flight environment.

  1. High time resolution laser induced fluorescence in pulsed argon plasma

    SciTech Connect

    Biloiu, Ioana A.; Sun Xuan; Scime, Earl E.

    2006-10-15

    A submillisecond time resolution laser induced fluorescence (LIF) method for obtaining the temporal evolution of the ion velocity distribution function in pulsed argon plasma is presented. A basic LIF system that employs a continuous laser wave pumping and lock-in aided detection of the subsequent fluorescence radiation is modified by addition of a high frequency acousto-optic modulator to provide measurements of the ion flow velocity and ion temperature in a helicon generated pulsed argon plasma with temporal resolutions as high as 30 {mu}s.

  2. On the application and extension of Harten's high resolution scheme

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Warming, R. F.; Harten, A.

    1982-01-01

    Extensions of a second order high resolution explicit method for the numerical computation of weak solutions of one dimensonal hyperbolic conservation laws are discussed. The main objectives were (1) to examine the shock resoluton of Harten's method for a two dimensional shock reflection problem, (2) to study the use of a high resolution scheme as a post-processor to an approximate steady state solution, and (3) to construct an implicit in the delta-form using Harten's scheme for the explicit operator and a simplified iteration matrix for the implicit operator.

  3. High-resolution low-dose scanning transmission electron microscopy

    PubMed Central

    Buban, James P.; Ramasse, Quentin; Gipson, Bryant; Browning, Nigel D.; Stahlberg, Henning

    2010-01-01

    During the past two decades instrumentation in scanning transmission electron microscopy (STEM) has pushed toward higher intensity electron probes to increase the signal-to-noise ratio of recorded images. While this is suitable for robust specimens, biological specimens require a much reduced electron dose for high-resolution imaging. We describe here protocols for low-dose STEM image recording with a conventional field-emission gun STEM, while maintaining the high-resolution capability of the instrument. Our findings show that a combination of reduced pixel dwell time and reduced gun current can achieve radiation doses comparable to low-dose TEM. PMID:19915208

  4. High-resolution low-dose scanning transmission electron microscopy.

    PubMed

    Buban, James P; Ramasse, Quentin; Gipson, Bryant; Browning, Nigel D; Stahlberg, Henning

    2010-01-01

    During the past two decades instrumentation in scanning transmission electron microscopy (STEM) has pushed toward higher intensity electron probes to increase the signal-to-noise ratio of recorded images. While this is suitable for robust specimens, biological specimens require a much reduced electron dose for high-resolution imaging. We describe here protocols for low-dose STEM image recording with a conventional field-emission gun STEM, while maintaining the high-resolution capability of the instrument. Our findings show that a combination of reduced pixel dwell time and reduced gun current can achieve radiation doses comparable to low-dose TEM.

  5. High-resolution setup for measuring wavelength sensitivity of photoyellowing of translucent materials

    NASA Astrophysics Data System (ADS)

    Vaskuri, Anna; Kärhä, Petri; Heikkilä, Anu; Ikonen, Erkki

    2015-10-01

    Polystyrene and many other materials turn yellow when exposed to ultraviolet (UV) radiation. All photodegradation mechanisms including photoyellowing are functions of the exposure wavelength, which can be described with an action spectrum. In this work, a new high-resolution transmittance measurement setup based on lasers has been developed for measuring color changes, such as the photoyellowing of translucent materials aged with a spectrograph. The measurement setup includes 14 power-stabilized laser lines between 325 nm and 933 nm wavelengths, of which one at a time is directed on to the aged sample. The power transmitted through the sample is measured with a silicon detector utilizing an integrating sphere. The sample is mounted on a high-resolution XY translation stage. Measurement at various locations aged with different wavelengths of exposure radiation gives the transmittance data required for acquiring the action spectrum. The combination of a UV spectrograph and the new high-resolution transmittance measurement setup enables a novel method for studying the UV-induced ageing of translucent materials with a spectral resolution of 3-8 nm, limited by the adjustable spectral bandwidth range of the spectrograph. These achievements form a significant improvement over earlier methods.

  6. High-resolution setup for measuring wavelength sensitivity of photoyellowing of translucent materials

    SciTech Connect

    Vaskuri, Anna Kärhä, Petri; Heikkilä, Anu

    2015-10-15

    Polystyrene and many other materials turn yellow when exposed to ultraviolet (UV) radiation. All photodegradation mechanisms including photoyellowing are functions of the exposure wavelength, which can be described with an action spectrum. In this work, a new high-resolution transmittance measurement setup based on lasers has been developed for measuring color changes, such as the photoyellowing of translucent materials aged with a spectrograph. The measurement setup includes 14 power-stabilized laser lines between 325 nm and 933 nm wavelengths, of which one at a time is directed on to the aged sample. The power transmitted through the sample is measured with a silicon detector utilizing an integrating sphere. The sample is mounted on a high-resolution XY translation stage. Measurement at various locations aged with different wavelengths of exposure radiation gives the transmittance data required for acquiring the action spectrum. The combination of a UV spectrograph and the new high-resolution transmittance measurement setup enables a novel method for studying the UV-induced ageing of translucent materials with a spectral resolution of 3–8 nm, limited by the adjustable spectral bandwidth range of the spectrograph. These achievements form a significant improvement over earlier methods.

  7. High resolution T2(*)-weighted Magnetic Resonance Imaging at 3 Tesla using PROPELLER-EPI.

    PubMed

    Krämer, Martin; Reichenbach, Jürgen R

    2014-05-01

    We report the application of PROPELLER-EPI for high resolution T2(*)-weighted imaging with sub-millimeter in-plane resolution on a clinical 3 Tesla scanner. Periodically rotated blades of a long-axis PROPELLER-EPI sequence were acquired with fast gradient echo readout and acquisition matrix of 320 × 50 per blade. Images were reconstructed by using 2D-gridding, phase and geometric distortion correction and compensation of resonance frequency drifts that occurred during extended measurements. To characterize these resonance frequency offsets, short FID calibration measurements were added to the PROPELLER-EPI sequence. Functional PROPELLER-EPI was performed with volunteers using a simple block design of right handed finger tapping. Results indicate that PROPELLER-EPI can be employed for fast, high resolution T2(*)-weighted imaging provided geometric distortions and possible resonance frequency drifts are properly corrected. Even small resonance frequency drifts below 10 Hz as well as non-corrected geometric distortions degraded image quality substantially. In the initial fMRI experiment image quality and signal-to-noise ratio was sufficient for obtaining high resolution functional activation maps.

  8. Drone-acquired structure-from-motion photogrammetry for high-precision measurements of biomass in semi-arid rangelands

    NASA Astrophysics Data System (ADS)

    Cunliffe, Andrew; Brazier, Richard; Anderson, Karen

    2016-04-01

    Covering 40% of the terrestrial surface, dryland ecosystems have a distinct vegetation structure that is strongly linked to their function. Recent global modelling studies have indicated interannual variations in semiarid ecosystem biomass accounts for ca. 40%-60% of interannual variations in atmospheric carbon dioxide concentrations. Empirical evidence is needed to validate these model predictions; however, existing survey approaches cannot provide sufficiently precise data at landscape-scale extents to quantify this structure appropriately. Using a small unpiloted aerial system (UAS) to acquire aerial photographs and processing using structure-from-motion (SfM) photogrammetry, three dimensional models were produced quantifying the vegetation structure of semi-arid ecosystems at seven areas of interest (AOI). This approach yielded ultrafine (<1 cm2) spatial resolution canopy height models over landscape-scales (10 ha), which resolved individual grass tussocks just a few cm3 in volume. Canopy height cumulative distributions for each AOI illustrated ecologically-significant differences in ecosystem structure over a grass- to shrub-dominated vegetation transition. Strong coefficients of determination (r2 >0.64) supported prediction of aboveground biomass from canopy volume. Canopy volumes, modelled biomass and carbon stocks were sensitive to spatial changes in vegetation community structure. We demonstrate the use of an inexpensive UAS and SfM photogrammetry to produce ultrafine-scale biophysical data products. The high-precision of this approach affords sensitivity to subtle differences in the biotic structure (and therefore function) of heterogeneous ecosystems subject to rapid environmental change, and has exciting potential to revolutionise the study of spatial ecology in ecosystems with either spatially or temporally discontinuous canopy cover.

  9. Progress in high-resolution x-ray holographic microscopy

    SciTech Connect

    Jacobsen, C.; Kirz, J.; Howells, M.; McQuaid, K.; Rothman, S.; Feder, R.; Sayre, D.

    1987-07-01

    Among the various types of x-ray microscopes that have been demonstrated, the holographic microscope has had the largest gap between promise and performance. The difficulties of fabricating x-ray optical elements have led some to view holography as the most attractive method for obtaining the ultimate in high resolution x-ray micrographs; however, we know of no investigations prior to 1987 that clearly demonstrated submicron resolution in reconstructed images. Previous efforts suffered from problems such as limited resolution and dynamic range in the recording media, low coherent x-ray flux, and aberrations and diffraction limits in visible light reconstruction. We have addressed the recording limitations through the use of an undulator x-ray source and high-resolution photoresist recording media. For improved results in the readout and reconstruction steps, we have employed metal shadowing and transmission electron microscopy, along with numerical reconstruction techniques. We believe that this approach will allow holography to emerge as a practical method of high-resolution x-ray microscopy. 30 refs., 4 figs.

  10. High-resolution EEG (HR-EEG) and magnetoencephalography (MEG).

    PubMed

    Gavaret, M; Maillard, L; Jung, J

    2015-03-01

    High-resolution EEG (HR-EEG) and magnetoencephalography (MEG) allow the recording of spontaneous or evoked electromagnetic brain activity with excellent temporal resolution. Data must be recorded with high temporal resolution (sampling rate) and high spatial resolution (number of channels). Data analyses are based on several steps with selection of electromagnetic signals, elaboration of a head model and use of algorithms in order to solve the inverse problem. Due to considerable technical advances in spatial resolution, these tools now represent real methods of ElectroMagnetic Source Imaging. HR-EEG and MEG constitute non-invasive and complementary examinations, characterized by distinct sensitivities according to the location and orientation of intracerebral generators. In the presurgical assessment of drug-resistant partial epilepsies, HR-EEG and MEG can characterize and localize interictal activities and thus the irritative zone. HR-EEG and MEG often yield significant additional data that are complementary to other presurgical investigations and particularly relevant in MRI-negative cases. Currently, the determination of the epileptogenic zone and functional brain mapping remain rather less well-validated indications. In France, in 2014, HR-EEG is now part of standard clinical investigation of epilepsy, while MEG remains a research technique.

  11. Apex: AN EUV High-Resolution Spectroscopic Observatory

    NASA Astrophysics Data System (ADS)

    Kowalski, Michael P.; Cruddace, Raymond G.; Wood, Kent S.; Yentis, Daryl J.; Barbee, Troy W., Jr.; Kordas, Joseph F.; Fritz, Gilbert G.; Barstow, Martin A.; Bannister, Nigel P.; Lapington, Jon S.

    The termination of the EUVE mission has left a hole in spectral coverage at crucial EUV wavelengths (~70-600 Å) where hot (0.1-10 MK) plasmas radiate most strongly and produce critical spectral diagnostics often not available at other wavelengths. CHIPS will fill this hole only partially as it is optimized for diffuse emission and has only moderate resolution (R~150). For discrete sources we have successfully flown on a sounding rocket a follow-on instrument to the EUVE spectrometer (Aeff ~1 cm2 R ~400) the high-resolution spectrometer J-PEX (Aeff ~3 cm2 R ~3000). An upgraded version with higher resolution and effective area has been approved for another rocket flight. Here we build on the J-PEX prototype and present a proposed design for an orbiting spectroscopic observatory APEX a SMEX-class instrument containing a suite of spectrometers that together achieve both high effective area (>20 cm2) and high spectral resolution (>10000) in the EUV. We discuss instrumental characteristics such as optical design wavelength coverage resolution and effective area. We also summarize science objectives for observations of stellar coronae accretion phenomena in cataclysmic variables and extragalactic objects white dwarfs and the interstellar medium.

  12. Wide-field, high-resolution Fourier ptychographic microscopy

    PubMed Central

    Zheng, Guoan; Horstmeyer, Roarke; Yang, Changhuei

    2014-01-01

    In this article, we report an imaging method, termed Fourier ptychographic microscopy (FPM), which iteratively stitches together a number of variably illuminated, low-resolution intensity images in Fourier space to produce a wide-field, high-resolution complex sample image. By adopting a wavefront correction strategy, the FPM method can also correct for aberrations and digitally extend a microscope’s depth-of-focus beyond the physical limitations of its optics. As a demonstration, we built a microscope prototype with a resolution of 0.78 μm, a field-of-view of ~120 mm2, and a resolution-invariant depth-of-focus of 0.3 mm (characterized at 632 nm). Gigapixel colour images of histology slides verify FPM’s successful operation. The reported imaging procedure transforms the general challenge of high-throughput, high-resolution microscopy from one that is coupled to the physical limitations of the system’s optics to one that is solvable through computation. PMID:25243016

  13. Multi-resolution voxel phantom modeling: a high-resolution eye model for computational dosimetry

    NASA Astrophysics Data System (ADS)

    Caracappa, Peter F.; Rhodes, Ashley; Fiedler, Derek

    2014-09-01

    Voxel models of the human body are commonly used for simulating radiation dose with a Monte Carlo radiation transport code. Due to memory limitations, the voxel resolution of these computational phantoms is typically too large to accurately represent the dimensions of small features such as the eye. Recently reduced recommended dose limits to the lens of the eye, which is a radiosensitive tissue with a significant concern for cataract formation, has lent increased importance to understanding the dose to this tissue. A high-resolution eye model is constructed using physiological data for the dimensions of radiosensitive tissues, and combined with an existing set of whole-body models to form a multi-resolution voxel phantom, which is used with the MCNPX code to calculate radiation dose from various exposure types. This phantom provides an accurate representation of the radiation transport through the structures of the eye. Two alternate methods of including a high-resolution eye model within an existing whole-body model are developed. The accuracy and performance of each method is compared against existing computational phantoms.

  14. New Challenges in High-Resolution Modeling of Hurricanes

    NASA Astrophysics Data System (ADS)

    Chen, S. S.

    2006-12-01

    The extreme active Atlantic hurricane seasons in recent years have highlighted the urgent need for a better understanding of the factors that contribute to hurricane intensity and for development of the corresponding advanced hurricane prediction models to improve intensity forecasts. The lack of skill in present forecasts of hurricane structure and intensity may be attributed in part to deficiencies in the current prediction models: insufficient grid resolution, inadequate surface and boundary layer formulations, and the lack of full coupling to a dynamic ocean. The extreme high winds, intense rainfall, large ocean waves, and copious sea spray in hurricanes push the surface-exchange parameters for temperature, water vapor, and momentum into untested regimes. The recent modeling effort is to develop and test a fully coupled atmosphere-wave-ocean modeling system that is capable of resolving the eye and eyewall in a hurricane at ~1 km grid resolution. The new challenges for these very high resolution models are the corresponding physical representations at 1-km scale, including microphysics, sub-grid turbulence parameterization, atmospheric boundary layer, physical processes at the air-sea interface with surface waves among others. The lack of accurate initial conditions for high-resolution hurricane modeling presents another major challenge. Improvements in initial conditions rest on the use of more airborne and remotely sensed observations in high-resolution assimilation systems and on the application of advanced assimilation schemes to hurricanes. This study aimed to provide an overview of these new challenges using high-resolution model simulations of Hurricanes Isabel (2003), Frances (2004), Katrina and Rita (2005) that were observed extensively by two recent field programs, namely, the Coupled Boundary Layer Air-Sea Transfer (CBLAST)-Hurricane in 2003-2004 and the Hurricane Rainbands and Intensity Change Experiment (RAINEX) in 2005.

  15. High-resolution structure of the native histone octamer

    PubMed Central

    Wood, Christopher M.; Nicholson, James M.; Lambert, Stanley J.; Chantalat, Laurent; Reynolds, Colin D.; Baldwin, John P.

    2005-01-01

    Crystals of native histone octamers (H2A–H2B)–(H4–H3)–(H3′–H4′)–(H2B′–­H2A′) from chick erythrocytes in 2 M KCl, 1.35 M potassium phosphate pH 6.9 diffract X-rays to 1.90 Å resolution, yielding a structure with an R work value of 18.7% and an R free of 22.2%. The crystal space group is P65, the asymmetric unit of which contains one complete octamer. This high-resolution model of the histone-core octamer allows further insight into intermolecular interactions, including water molecules, that dock the histone dimers to the tetramer in the nucleosome-core particle and have relevance to nucleosome remodelling. The three key areas analysed are the H2A′–H3–H4 molecular cluster (also H2A–H3′–H4′), the H4–H2B′ interaction (also H4′–H2B) and the H2A′–H4 β-sheet interaction (also H2A–H4′). The latter of these three regions is important to nucleosome remodelling by RNA polymerase II, as it is shown to be a likely core-histone binding site, and its disruption creates an instability in the nucleosome-core particle. A majority of the water molecules in the high-resolution octamer have positions that correlate to similar positions in the high-­resolution nucleosome-core particle structure, suggesting that the high-resolution octamer model can be used for comparative studies with the high-resolution nucleosome-core particle. PMID:16511091

  16. Converting Multi-Shell and Diffusion Spectrum Imaging to High Angular Resolution Diffusion Imaging.

    PubMed

    Yeh, Fang-Cheng; Verstynen, Timothy D

    2016-01-01

    Multi-shell and diffusion spectrum imaging (DSI) are becoming increasingly popular methods of acquiring diffusion MRI data in a research context. However, single-shell acquisitions, such as diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), still remain the most common acquisition schemes in practice. Here we tested whether multi-shell and DSI data have conversion flexibility to be interpolated into corresponding HARDI data. We acquired multi-shell and DSI data on both a phantom and in vivo human tissue and converted them to HARDI. The correlation and difference between their diffusion signals, anisotropy values, diffusivity measurements, fiber orientations, connectivity matrices, and network measures were examined. Our analysis result showed that the diffusion signals, anisotropy, diffusivity, and connectivity matrix of the HARDI converted from multi-shell and DSI were highly correlated with those of the HARDI acquired on the MR scanner, with correlation coefficients around 0.8~0.9. The average angular error between converted and original HARDI was 20.7° at voxels with signal-to-noise ratios greater than 5. The network topology measures had less than 2% difference, whereas the average nodal measures had a percentage difference around 4~7%. In general, multi-shell and DSI acquisitions can be converted to their corresponding single-shell HARDI with high fidelity. This supports multi-shell and DSI acquisitions over HARDI acquisition as the scheme of choice for diffusion acquisitions.

  17. Converting Multi-Shell and Diffusion Spectrum Imaging to High Angular Resolution Diffusion Imaging

    PubMed Central

    Yeh, Fang-Cheng; Verstynen, Timothy D.

    2016-01-01

    Multi-shell and diffusion spectrum imaging (DSI) are becoming increasingly popular methods of acquiring diffusion MRI data in a research context. However, single-shell acquisitions, such as diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), still remain the most common acquisition schemes in practice. Here we tested whether multi-shell and DSI data have conversion flexibility to be interpolated into corresponding HARDI data. We acquired multi-shell and DSI data on both a phantom and in vivo human tissue and converted them to HARDI. The correlation and difference between their diffusion signals, anisotropy values, diffusivity measurements, fiber orientations, connectivity matrices, and network measures were examined. Our analysis result showed that the diffusion signals, anisotropy, diffusivity, and connectivity matrix of the HARDI converted from multi-shell and DSI were highly correlated with those of the HARDI acquired on the MR scanner, with correlation coefficients around 0.8~0.9. The average angular error between converted and original HARDI was 20.7° at voxels with signal-to-noise ratios greater than 5. The network topology measures had less than 2% difference, whereas the average nodal measures had a percentage difference around 4~7%. In general, multi-shell and DSI acquisitions can be converted to their corresponding single-shell HARDI with high fidelity. This supports multi-shell and DSI acquisitions over HARDI acquisition as the scheme of choice for diffusion acquisitions. PMID:27683539

  18. Converting Multi-Shell and Diffusion Spectrum Imaging to High Angular Resolution Diffusion Imaging.

    PubMed

    Yeh, Fang-Cheng; Verstynen, Timothy D

    2016-01-01

    Multi-shell and diffusion spectrum imaging (DSI) are becoming increasingly popular methods of acquiring diffusion MRI data in a research context. However, single-shell acquisitions, such as diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), still remain the most common acquisition schemes in practice. Here we tested whether multi-shell and DSI data have conversion flexibility to be interpolated into corresponding HARDI data. We acquired multi-shell and DSI data on both a phantom and in vivo human tissue and converted them to HARDI. The correlation and difference between their diffusion signals, anisotropy values, diffusivity measurements, fiber orientations, connectivity matrices, and network measures were examined. Our analysis result showed that the diffusion signals, anisotropy, diffusivity, and connectivity matrix of the HARDI converted from multi-shell and DSI were highly correlated with those of the HARDI acquired on the MR scanner, with correlation coefficients around 0.8~0.9. The average angular error between converted and original HARDI was 20.7° at voxels with signal-to-noise ratios greater than 5. The network topology measures had less than 2% difference, whereas the average nodal measures had a percentage difference around 4~7%. In general, multi-shell and DSI acquisitions can be converted to their corresponding single-shell HARDI with high fidelity. This supports multi-shell and DSI acquisitions over HARDI acquisition as the scheme of choice for diffusion acquisitions. PMID:27683539

  19. Converting Multi-Shell and Diffusion Spectrum Imaging to High Angular Resolution Diffusion Imaging

    PubMed Central

    Yeh, Fang-Cheng; Verstynen, Timothy D.

    2016-01-01

    Multi-shell and diffusion spectrum imaging (DSI) are becoming increasingly popular methods of acquiring diffusion MRI data in a research context. However, single-shell acquisitions, such as diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), still remain the most common acquisition schemes in practice. Here we tested whether multi-shell and DSI data have conversion flexibility to be interpolated into corresponding HARDI data. We acquired multi-shell and DSI data on both a phantom and in vivo human tissue and converted them to HARDI. The correlation and difference between their diffusion signals, anisotropy values, diffusivity measurements, fiber orientations, connectivity matrices, and network measures were examined. Our analysis result showed that the diffusion signals, anisotropy, diffusivity, and connectivity matrix of the HARDI converted from multi-shell and DSI were highly correlated with those of the HARDI acquired on the MR scanner, with correlation coefficients around 0.8~0.9. The average angular error between converted and original HARDI was 20.7° at voxels with signal-to-noise ratios greater than 5. The network topology measures had less than 2% difference, whereas the average nodal measures had a percentage difference around 4~7%. In general, multi-shell and DSI acquisitions can be converted to their corresponding single-shell HARDI with high fidelity. This supports multi-shell and DSI acquisitions over HARDI acquisition as the scheme of choice for diffusion acquisitions.

  20. An Automated Platform for High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry

    SciTech Connect

    Lanekoff, Ingela T.; Heath, Brandi S.; Liyu, Andrey V.; Thomas, Mathew; Carson, James P.; Laskin, Julia

    2012-10-02

    An automated platform has been developed for acquisition and visualization of mass spectrometry imaging (MSI) data using nanospray desorption electrospray ionization (nano-DESI). The new system enables robust operation of the nano-DESI imaging source over many hours. This is achieved by controlling the distance between the sample and the probe by mounting the sample holder onto an automated XYZ stage and defining the tilt of the sample plane. This approach is useful for imaging of relatively flat samples such as thin tissue sections. Custom software called MSI QuickView was developed for visualization of large data sets generated in imaging experiments. MSI QuickView enables fast visualization of the imaging data during data acquisition and detailed processing after the entire image is acquired. The performance of the system is demonstrated by imaging rat brain tissue sections. High resolution mass analysis combined with MS/MS experiments enabled identification of lipids and metabolites in the tissue section. In addition, high dynamic range and sensitivity of the technique allowed us to generate ion images of low-abundance isobaric lipids. High-spatial resolution image acquired over a small region of the tissue section revealed the spatial distribution of an abundant brain metabolite, creatine, in the white and gray matter that is consistent with the literature data obtained using magnetic resonance spectroscopy.

  1. New high-resolution IR-color reflectography scanner for painting diagnosis

    NASA Astrophysics Data System (ADS)

    Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Marras, Luciano; Materazzi, Marzia; Pampaloni, Enrico; Pezzati, Luca; Poggi, Pasquale

    2003-10-01

    Infrared reflectography is a prominent optical technique for non-destructive diagnostics of paintings, which allows the visualisation of details hidden by the paint layers, because of their transparency characteristics to IR radiation. High-resolution reflectography was introduced around the end of the 80s by the Istituto Nazionale di Ottica Applicata, where a prototype of an innovative scanner device was developed. This technique was recently improved with the introduction of a new optical head, able to acquire simultaneously the reflectogram and the colour image, perfectly superimposing. The technical characteristics of the IR-colour scanner guarantee: a high spatial resolution (16 points/mm2), a high tonal dynamics (thousands of grey levels), a uniform lighting of the scanned area and the punctual superimposition of the colour and IR images. Moreover we can print distortion-free reflectograms, false-colour and colour images of paintings on a 1:1 scale. The quality of the acquired reflectogram is presently higher than that obtainable with any traditional detection system, like CCD or Vidicon cameras. The point-by-point comparison between the reflectogram and the colour image of the painting, along with digital processing of the recorded images, open new possibilities for the analysis of the reflectogram. Some examples of application to the study of ancient paintings are shown.

  2. High Resolution Simulations of Future Climate in West Africa Using a Variable-Resolution Atmospheric Model

    NASA Astrophysics Data System (ADS)

    Adegoke, J. O.; Engelbrecht, F.; Vezhapparambu, S.

    2013-12-01

    In previous work demonstrated the application of a var¬iable-resolution global atmospheric model, the conformal-cubic atmospheric model (CCAM), across a wide range of spatial and time scales to investigate the ability of the model to provide realistic simulations of present-day climate and plausible projections of future climate change over sub-Saharan Africa. By applying the model in stretched-grid mode the versatility of the model dynamics, numerical formulation and physical parameterizations to function across a range of length scales over the region of interest, was also explored. We primarily used CCAM to illustrate the capability of the model to function as a flexible downscaling tool at the climate-change time scale. Here we report on additional long term climate projection studies performed by downscaling at much higher resolutions (8 Km) over an area that stretches from just south of Sahara desert to the southern coast of the Niger Delta and into the Gulf of Guinea. To perform these simulations, CCAM was provided with synoptic-scale forcing of atmospheric circulation from 2.5 deg resolution NCEP reanalysis at 6-hourly interval and SSTs from NCEP reanalysis data uses as lower boundary forcing. CCAM 60 Km resolution downscaled to 8 Km (Schmidt factor 24.75) then 8 Km resolution simulation downscaled to 1 Km (Schmidt factor 200) over an area approximately 50 Km x 50 Km in the southern Lake Chad Basin (LCB). Our intent in conducting these high resolution model runs was to obtain a deeper understanding of linkages between the projected future climate and the hydrological processes that control the surface water regime in this part of sub-Saharan Africa.

  3. High resolution map of light pollution over Poland

    NASA Astrophysics Data System (ADS)

    Netzel, Henryka; Netzel, Paweł

    2016-09-01

    In 1976 Berry introduced a simple mathematical equation to calculate artificial night sky brightness at zenith. In the original model cities, considered as points with given population, are only sources of light emission. In contrary to Berry's model, we assumed that all terrain surface can be a source of light. Emission of light depends on percent of built up area in a given cell. We based on Berry's model. Using field measurements and high-resolution data we obtained the map of night sky brightness over Poland in 100-m resolution. High resolution input data, combined with a very simple model, makes it possible to obtain detailed structures of the night sky brightness without complicating the calculations.

  4. Science with High Spatial Resolution Far-Infrared Data

    NASA Technical Reports Server (NTRS)

    Terebey, Susan (Editor); Mazzarella, Joseph M. (Editor)

    1994-01-01

    The goal of this workshop was to discuss new science and techniques relevant to high spatial resolution processing of far-infrared data, with particular focus on high resolution processing of IRAS data. Users of the maximum correlation method, maximum entropy, and other resolution enhancement algorithms applicable to far-infrared data gathered at the Infrared Processing and Analysis Center (IPAC) for two days in June 1993 to compare techniques and discuss new results. During a special session on the third day, interested astronomers were introduced to IRAS HIRES processing, which is IPAC's implementation of the maximum correlation method to the IRAS data. Topics discussed during the workshop included: (1) image reconstruction; (2) random noise; (3) imagery; (4) interacting galaxies; (5) spiral galaxies; (6) galactic dust and elliptical galaxies; (7) star formation in Seyfert galaxies; (8) wavelet analysis; and (9) supernova remnants.

  5. High-resolution x-ray phase tomography

    NASA Astrophysics Data System (ADS)

    Peele, Andrew G.; Thomas, C. David L.; Clement, John G.; Arhatari, Benedicta D.; Hannah, Kevin M.; Doshi, Chandni; Putkunz, Corey T.; Clark, Jesse N.

    2010-09-01

    X-ray tomography is a workhorse tool of non-destructive imaging. It is used to probe three-dimensional structures across a wide range of length scales for objects that offer good absorption contrast to x-rays. In recent years extremely high resolution imaging (on the order of tens of nanometres) has become possible due to technological advances in x-ray optics. At the same time the requirement for strong absorption contrast has been relaxed thanks to the advent of new experimental and algorithmic techniques in phase imaging. Advances in both resolution and phase imaging can be combined to image biological samples at the sub-cellular level. I will report on recent advances in our work including improvements to the current approaches in extracting phase information at high resolution from measurements of the diffracted intensity from a sample. I will also discuss our current experimental status.

  6. Note: Differential amplified high-resolution tilt angle measurement system.

    PubMed

    Zhao, Shijie; Li, Yan; Zhang, Enyao; Huang, Pei; Wei, Haoyun

    2014-09-01

    A high-resolution tilt angle measurement system is presented in this paper. In this system, the measurement signal is amplified by two steps: (1) amplified by operational amplifier and (2) differential amplified by two MEMS-based inclinometers. The novel application not only amplifies the signal but, more importantly, substantially reduces the electrical interference and common-mode noise among the same circuit design. Thus, both the extremely high resolution and great long-term stability are achieved in this system. Calibrated by an autocollimator, the system shows a resolution of 2 arc sec. The accuracy is better than ±1.5 arc sec. The zero-drift error is below ±1 arc sec and ±2 arc sec in the short and long term, respectively.

  7. Note: Differential amplified high-resolution tilt angle measurement system

    NASA Astrophysics Data System (ADS)

    Zhao, Shijie; Li, Yan; Zhang, Enyao; Huang, Pei; Wei, Haoyun

    2014-09-01

    A high-resolution tilt angle measurement system is presented in this paper. In this system, the measurement signal is amplified by two steps: (1) amplified by operational amplifier and (2) differential amplified by two MEMS-based inclinometers. The novel application not only amplifies the signal but, more importantly, substantially reduces the electrical interference and common-mode noise among the same circuit design. Thus, both the extremely high resolution and great long-term stability are achieved in this system. Calibrated by an autocollimator, the system shows a resolution of 2 arc sec. The accuracy is better than ±1.5 arc sec. The zero-drift error is below ±1 arc sec and ±2 arc sec in the short and long term, respectively.

  8. Parallelization and Algorithmic Enhancements of High Resolution IRAS Image Construction

    NASA Technical Reports Server (NTRS)

    Cao, Yu; Prince, Thomas A.; Tereby, Susan; Beichman, Charles A.

    1996-01-01

    The Infrared Astronomical Satellite caried out a nearly complete survey of the infrared sky, and the survey data are important for the study of many astrophysical phenomena. However, many data sets at other wavelengths have higher resolutions than that of the co-added IRAS maps, and high resolution IRAS images are strongly desired both for their own information content and their usefulness in correlation. The HIRES program was developed by the Infrared Processing and Analysis Center (IPAC) to produce high resolution (approx. 1') images from IRAS data using the Maximum Correlation Method (MCM). We describe the port of HIRES to the Intel Paragon, a massively parallel supercomputer, other software developments for mass production of HIRES images, and the IRAS Galaxy Atlas, a project to map the Galactic plane at 60 and 100(micro)m.

  9. Building a global high resolution atmosphere climate simulation capability

    NASA Astrophysics Data System (ADS)

    Evans, K. J.

    2011-12-01

    Recent work to configure the Community Climate System Model, version 4 (CCSM4), to run climate-length simulations using a high spatial resolution spectral Eulerian dynamical core is underway. Present day climate simulations using coupled and uncoupled configurations of the equivalent 1 degree spectral dynamical core option in the CCSM4 produce better alignment with observations compared to the CCSM3 and a similar climate compared to equivalent default finite volume configurations. Using the 1 degree results and observations as a benchmark, equivalent 1/4 degree resolution spectral model climate simulations produce mixed results; there some are better resolved dynamical features, but also some deficiencies in the hydrological cycle. Several benefits, challenges, and recommendations to improve high-resolution modeling are discussed.

  10. High-resolution confocal Raman microscopy using pixel reassignment.

    PubMed

    Roider, Clemens; Ritsch-Marte, Monika; Jesacher, Alexander

    2016-08-15

    We present a practical modification of fiber-coupled confocal Raman scanning microscopes that is able to provide high confocal resolution in conjunction with high light collection efficiency. For this purpose, the single detection fiber is replaced by a hexagonal lenslet array in combination with a hexagonally packed round-to-linear multimode fiber bundle. A multiline detector is used to collect individual Raman spectra for each fiber. Data post-processing based on pixel reassignment allows one to improve the lateral resolution by up to 41% compared to a single fiber of equal light collection efficiency. We present results from an experimental implementation featuring seven collection fibers, yielding a resolution improvement of about 30%. We believe that our implementation represents an attractive upgrade for existing confocal Raman microscopes that employ multi-line detectors. PMID:27519099

  11. Unsupervised Feature Learning for High-Resolution Satellite Image Classification

    SciTech Connect

    Cheriyadat, Anil M

    2013-01-01

    The rich data provided by high-resolution satellite imagery allow us to directly model geospatial neighborhoods by understanding their spatial and structural patterns. In this paper we explore an unsupervised feature learning approach to model geospatial neighborhoods for classification purposes. While pixel and object based classification approaches are widely used for satellite image analysis, often these approaches exploit the high-fidelity image data in a limited way. In this paper we extract low-level features to characterize the local neighborhood patterns. We exploit the unlabeled feature measurements in a novel way to learn a set of basis functions to derive new features. The derived sparse feature representation obtained by encoding the measured features in terms of the learned basis function set yields superior classification performance. We applied our technique on two challenging image datasets: ORNL dataset representing one-meter spatial resolution satellite imagery representing five land-use categories and, UCMERCED dataset consisting of 21 different categories representing sub-meter resolution overhead imagery. Our results are highly promising and, in the case of UCMERCED dataset we outperform the best results obtained for this dataset. We show that our feature extraction and learning methods are highly effective in developing a detection system that can be used to automatically scan large-scale high-resolution satellite imagery for detecting large-facility.

  12. High angular resolution millimeter observations of circumstellar disks

    NASA Astrophysics Data System (ADS)

    Testi, Leonard; Leurini, Silvia

    2008-06-01

    In this lecture, we review the properties of protoplanetary disks as derived from high angular resolution observations at millimeter wavelengths. We discuss how the combination of several different high angular resolution techniques allow us to probe different regions of the disk around young stellar objects and to derive the properties of the dust when combined with sophisticated disk models. The picture that emerges is that the dust in circumstellar disks surrounding pre-main sequence stars is in many cases significantly evolved compared to the dust in molecular clouds and the interstellar medium. It is however still difficult to derive a consistent picture and timeline for dust evolution in disks as the observations are still limited to small samples of objects. We also review the evidence for and properties of disks around high-mass young stellar objects and the implications on their formation mechanisms. The study of massive YSOs is complicated by their short lifetimes and larger average distances. In most cases high angular resolution data at millimeter wavelengths are the only method to probe the structure of disks in these objects. We provide a summary of the characteristics of available high angular resolution millimeter and submillimeter observatories. We also describe the characteristics of the ALMA observatory being constructed in the Chilean Andes. ALMA is going to be the world leading observatory at millimeter wavelengths in the coming decades, the project is now in its main construction phase with early science activities envisaged for 2010 and full science operations for 2012.

  13. High-resolution TFT-LCD for spatial light modulator

    NASA Astrophysics Data System (ADS)

    Lee, JaeWon; Kim, Yong-Hae; Byun, Chun-Won; Pi, Jae-Eun; Oh, Himchan; Kim, GiHeon; Lee, Myung-Lae; Chu, Hye-Yong; Hwang, Chi-Sun

    2014-06-01

    SLM with very fine pixel pitch is needed for the holographic display system. Among various kinds of SLMs, commercially available high resolution LCoS has been widely used as a spatial light modulator. But the size of commercially available LCoS SLM is limited because the manufacturing technology of LCoS is based on the semiconductor process developed on small size Si wafer. Recently very high resolution flat panel display panel (~500ppi) was developed as a "retina display". Until now, the pixel pitch of flat panel display is several times larger than the pixel pitch of LCoS. But considering the possibility of shrink down the pixel pitch with advanced lithographic tools, the application of flat panel display will make it possible to build a SLM with high spatial bandwidth product. We simulated High resolution TFT-LCD panel on glass substrate using oxide semiconductor TFT with pixel pitch of 20um. And we considered phase modulation behavior of LC(ECB) mode. The TFT-LCD panel is reflective type with 4-metal structure with organic planarization layers. The technical challenge for high resolution large area SLM will be discussed with very fine pixel.

  14. High Resolution Observations and Modeling of Small-Scale Solar Magnetic Elements

    NASA Technical Reports Server (NTRS)

    Berger, Thomas E.

    2001-01-01

    This research contract investigating the radiative transfer and dynamic physics of the smallest observable magnetic structures in the solar photosphere. Due to the lack of a high-resolution visible light satellite instrument for solar studies, all data were acquired using ground-based instrumentation. The primary goal of the investigation was to understand the formation and evolution of "G-band bright points" in relation to the associated magnetic elements. G-band bright points are small (on the order of 100 kin or less in diameter) bright signatures associated with magnetic flux elements in the photosphere. They are seen in the A2A-X2 4308 A molecular bandhead of the CH radical ill the solar spectrum and offer the highest spatial resolution and highest contrast "tracers" of small magnetic structure on the Sun.

  15. High-resolution seismic reflection survey at the Manson crater, Iowa

    NASA Technical Reports Server (NTRS)

    Keiswetter, D. A.; Black, R.; Steeples, D. W.; Anderson, R. R.

    1993-01-01

    Approximately 17.4 km of high-resolution reflection data were acquired along an east-west radius of the Manson Impact Structure (MIS) to delineate the shallow (upper 300 m) subsurface structural configuration. The geometry of the shallow structure is poorly known due to a 30-90 m thick Pleistocene till cover. The resolution of the new seismic data is roughly 5-10 times that of existing Vibroseis data. Data quality varies rapidly along the line from exceptional to poor, due primarily to velocity variations associated with the geological complexity of the area. Preliminary results indicate subsurface structural blocks previously envisioned to be several hundreds of meters in size are actually an order of magnitude smaller and more complex. A seismogram-by-seismogram analysis is necessary to confidently identify intricate stratigraphic and structural relationships seen on preliminary CDP sections, as numerous faults, diffractions, and complicated reflection patterns create potential pitfalls.

  16. High Resolution Urban Feature Extraction for Global Population Mapping using High Performance Computing

    SciTech Connect

    Vijayaraj, Veeraraghavan; Bright, Eddie A; Bhaduri, Budhendra L

    2007-01-01

    The advent of high spatial resolution satellite imagery like Quick Bird (0.6 meter) and IKONOS (1 meter) has provided a new data source for high resolution urban land cover mapping. Extracting accurate urban regions from high resolution images has many applications and is essential to the population mapping efforts of Oak Ridge National Laboratory's (ORNL) LandScan population distribution program. This paper discusses an automated parallel algorithm that has been implemented on a high performance computing environment to extract urban regions from high resolution images using texture and spectral features

  17. Using High Resolution Balloon Photography to Provide Topographic Data

    NASA Astrophysics Data System (ADS)

    Russell, K.; Bauer, T.

    2009-12-01

    For site-scale projects, the Bureau of Reclamation has used low altitude balloon photogrammetry to obtain high-resolution photographs and detailed topographic information. These data are collected in a fraction of the time and effort it would take to obtain a similar level of detail using traditional methods. This is accomplished at a significantly reduced cost compared to flying LiDAR or aerial photography, which can be prohibitively expensive for small or medium scale projects. Low altitude balloon photogrammetry is a process where overlapping photographs and ground survey control points are input into a photogrammetry software program (AdamTechnology 3DM Analyst Mine Mapping Suite) to produce orthophotographs and digital terrain model (DTM) elevation points. To acquire the photos a digital camera is attached to an 8-foot diameter helium balloon. The balloon is tethered and flown above the location of interest. The camera is controlled remotely while a live image is transmitted to a receiver on the ground. Ground survey control is established by using GPS equipment to survey ground targets placed within the area to be photographed. There are limitations to the process. Data collection is very weather dependent; too much wind causes the balloon to be unstable. Site conditions also determine the feasibility: power lines, trees, and steep embankments can cause difficulties maneuvering the balloon. Although some of the photographs show the underwater portion of the channel; there is little agreement between GPS points and the processed DTM elevations in the channel. The balloon has been used to survey large woody debris (LWD) structures and channel morphology in the Middle Fork John Day River (central Oregon) and monitoring debris after the removal of Chiloquin Dam (Sprague River, southern Oregon). Seventeen LWD structures were installed on the Middle Fork John Day River near John Day, OR in 2007 and 2008 to provide aquatic habitat. Balloon photos were obtained in

  18. High-Resolution Characterization of Intertidal Geomorphology by TLS

    NASA Astrophysics Data System (ADS)

    Guarnieri, A.; Vettore, A.; Marani, M.

    2007-12-01

    Observational fluvial geomorphology has greatly benefited in the last decades from the wide availability of digital terrain data obtained by orthophotos and by means of accurate airborne laser scanner data (LiDAR). On the contrary, the spatially-distributed study of the geomorphology of intertidal areas, such as tidal flats and marshes, remains problematic owing to the small relief characterizing such environments, often of the order of a few tens of centimetres, i.e. comparable to the accuracy of state-of-the-art LiDAR data. Here we present the results of Terrestrial Laser Scanner (TLS) acquisitions performed within a tidal marsh in the Venice lagoon. The survey was performed using a Leica HDS 3000 TLS, characterized by a large Field of View (360 deg H x 270 deg V), a low beam divergence (< 6 mm at 50 m) and a nominal accuracy of 6 mm at 50 m. The acquisition was performed at low tide to avoid interferences due to water on the marsh surface and, to minimize shadowing effects due to the tilting of the laser beam (especially in the channel network), the scanner was mounted on a custom-built tripod 3 m above the marsh surface. The area of the marsh, about 100m x 150m, was fully surveyed by just 2 scans. A total amount of about 3 million points was acquired, with an average measurement density of 200 points/m2. In order to reconstruct the geometry of the marsh, the two scans were co-registered using 8 reflective targets as matching points. Such targets were placed within the area of interest and surveyed with high accuracy (2 mm), while their position in the Italian national grid was determined with a double-frequency GPS receiver, in order to georeference the point clouds within an absolute framework. Post-processing of the very high resolution data obtained shows that the laser returns coming from the low vegetation present (about 0.5-1.0 m high) can be satisfactorily separated from those coming from the marsh surface, allowing the construction of a DSM and a DTM

  19. A microfluidic device to acquire high-magnification microphotographs of yeast cells

    PubMed Central

    Ohnuki, Shinsuke; Nogami, Satoru; Ohya, Yoshikazu

    2009-01-01

    Background Yeast cell morphology was investigated to reveal the molecular mechanisms of cell morphogenesis and to identify key factors of other processes such as cell cycle progression. We recently developed a semi-automatic image processing program called CalMorph, which allows us to quantitatively analyze yeast cell morphology with the 501 parameters as biological traits and uncover statistical relationships between cell morphological phenotypes and genotypes. However, the current semi-automatic method is not suitable for morphological analysis of large-scale yeast mutants for the reliable prediction of gene functions because of its low-throughput especially at the manual image-acquiring process. Results In this study, we developed a microfluidic chip designed to acquire successive microscopic images of yeast cells suitable for CalMorph image analysis. With the microfluidic chip, the morphology of living cells and morphological changes that occur during the cell cycle were successfully characterized. Conclusion The microfluidic chip enabled us to acquire the images faster than the conventional method. We speculate that the use of microfluidic chip is effective in acquiring images of large-scale for automated analysis of yeast strains. PMID:19317904

  20. A compact high-resolution X-ray powder diffractometer

    PubMed Central

    Fewster, Paul F.; Trout, David R. D.

    2013-01-01

    A new powder diffractometer operating in transmission mode is described. It can work as a rapid very compact instrument or as a high-resolution instrument, and the sample preparation is simplified. The incident beam optics create pure Cu Kα1 radiation, giving rise to peak widths of ∼0.1° in 2θ in compact form with a sample-to-detector minimum radius of 55 mm, reducing to peak widths of <0.05° in high-resolution mode by increasing the detector radius to 240 mm. The resolution of the diffractometer is shown to be governed by a complex mixture of angular divergence, sample size, diffraction effects and the dimensions of the detector pixels. The data can be collected instantaneously, which combined with trivial sample preparation and no sample alignment, makes it a suitable method for very rapid phase identification. As the detector is moved further from the sample, the angular step from the pixel dimension is reduced and the resolution improves significantly for very detailed studies, including structure determination and analysis of the microstructure. The advantage of this geometry is that the resolution of the diffractometer can be calculated precisely and the instrumental artefacts can be analysed easily without a sample present. The performance is demonstrated with LaB6 and paracetamol, and a critical appraisal of the uncertainties in the measurements is presented. The instantaneous data collection offers possibilities in dynamic experiments. PMID:24282331

  1. Immersion Gratings for Infrared High-resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sarugaku, Yuki; Ikeda, Yuji; Kobayashi, Naoto; Kaji, Sayumi; Sukegawa, Takashi; Sugiyama, Shigeru; Nakagawa, Takao; Arasaki, Takayuki; Kondo, Sohei; Nakanishi, Kenshi; Yasui, Chikako; Kawakita, Hideyo

    2016-10-01

    High-resolution spectroscopy in the infrared wavelength range is essential for observations of minor isotopologues, such as HDO for water, and prebiotic organic molecules like hydrocarbons/P-bearing molecules because numerous vibrational molecular bands (including non-polar molecules) are located in this wavelength range. High spectral resolution enables us to detect weak lines without spectral line confusion. This technique has been widely used in planetary sciences, e.g., cometary coma (H2O, CO, and organic molecules), the martian atmosphere (CH4, CO2, H2O and HDO), and the upper atmosphere of gas giants (H3+ and organic molecules such as C2H6). Spectrographs with higher resolution (and higher sensitivity) still have a potential to provide a plenty of findings. However, because the size of spectrographs scales with the spectral resolution, it is difficult to realize it.Immersion grating (IG), which is a diffraction grating wherein the diffraction surface is immersed in a material with a high refractive index (n > 2), provides n times higher spectral resolution compared to a reflective grating of the same size. Because IG reduces the size of spectrograph to 1/n compared to the spectrograph with the same spectral resolution using a conventional reflective grating, it is widely acknowledged as a key optical device to realize compact spectrographs with high spectral resolution.Recently, we succeeded in fabricating a CdZnTe immersion grating with the theoretically predicted diffraction efficiency by machining process using an ultrahigh-precision five-axis processing machine developed by Canon Inc. Using the same technique, we completed a practical germanium (Ge) immersion grating with both a reflection coating on the grating surface and the an AR coating on the entrance surface. It is noteworthy that the wide wavelength range from 2 to 20 um can be covered by the two immersion gratings.In this paper, we present the performances and the applications of the immersion

  2. High-Resolution Electronics: Spontaneous Patterning of High-Resolution Electronics via Parallel Vacuum Ultraviolet (Adv. Mater. 31/2016).

    PubMed

    Liu, Xuying; Kanehara, Masayuki; Liu, Chuan; Sakamoto, Kenji; Yasuda, Takeshi; Takeya, Jun; Minari, Takeo

    2016-08-01

    On page 6568, T. Minari and co-workers describe spontaneous patterning based on the parallel vacuum ultraviolet (PVUV) technique, enabling the homogeneous integration of complex, high-resolution electronic circuits, even on large-scale, flexible, transparent substrates. Irradiation of PVUV to the hydrophobic polymer surface precisely renders the selected surface into highly wettable regions with sharply defined boundaries, which spontaneously guides a metal nanoparticle ink into a series of circuit lines and gaps with the widths down to a resolution of 1 μm.

  3. High-Resolution Electronics: Spontaneous Patterning of High-Resolution Electronics via Parallel Vacuum Ultraviolet (Adv. Mater. 31/2016).

    PubMed

    Liu, Xuying; Kanehara, Masayuki; Liu, Chuan; Sakamoto, Kenji; Yasuda, Takeshi; Takeya, Jun; Minari, Takeo

    2016-08-01

    On page 6568, T. Minari and co-workers describe spontaneous patterning based on the parallel vacuum ultraviolet (PVUV) technique, enabling the homogeneous integration of complex, high-resolution electronic circuits, even on large-scale, flexible, transparent substrates. Irradiation of PVUV to the hydrophobic polymer surface precisely renders the selected surface into highly wettable regions with sharply defined boundaries, which spontaneously guides a metal nanoparticle ink into a series of circuit lines and gaps with the widths down to a resolution of 1 μm. PMID:27511534

  4. Human enamel structure studied by high resolution electron microscopy

    SciTech Connect

    Wen, S.L. )

    1989-01-01

    Human enamel structural features are characterized by high resolution electron microscopy. The human enamel consists of polycrystals with a structure similar to Ca10(PO4)6(OH)2. This article describes the structural features of human enamel crystal at atomic and nanometer level. Besides the structural description, a great number of high resolution images are included. Research into the carious process in human enamel is very important for human beings. This article firstly describes the initiation of caries in enamel crystal at atomic and unit-cell level and secondly describes the further steps of caries with structural and chemical demineralization. The demineralization in fact, is the origin of caries in human enamel. The remineralization of carious areas in human enamel has drawn more and more attention as its potential application is realized. This process has been revealed by high resolution electron microscopy in detail in this article. On the other hand, the radiation effects on the structure of human enamel are also characterized by high resolution electron microscopy. In order to reveal this phenomenon clearly, a great number of electron micrographs have been shown, and a physical mechanism is proposed. 26 references.

  5. High-resolution imaging of upper limb neuropathies.

    PubMed

    Howe, Benjamin Matthew; Spinner, Robert J; Felmlee, Joel P; Amrami, Kimberly K

    2015-04-01

    MRI of the peripheral nerves continues to grow technologically and in clinical use. This article reviews the technological aspects and basic interpretation of high-resolution MR imaging of the upper extremity nerves. These techniques work with 1.5-, or preferably 3-T, scanners regardless of vendors. The article also includes selected pitfalls in the interpretation of upper extremity nerve MRI.

  6. Persistence Diagrams of High-Resolution Temporal Rainfall

    NASA Astrophysics Data System (ADS)

    Fernández Méndez, F.; Carsteanu, A. A.

    2015-12-01

    This study applies Topological Data Analysis (TDA), by generating persistence diagrams to uncover patterns in the data of high-resolution temporal rainfall intensities from Iowa City (IIHR, U of Iowa). Persistence diagrams are a way to identify essential cycles in state-space representations of the data.

  7. Application of Classification Models to Pharyngeal High-Resolution Manometry

    ERIC Educational Resources Information Center

    Mielens, Jason D.; Hoffman, Matthew R.; Ciucci, Michelle R.; McCulloch, Timothy M.; Jiang, Jack J.

    2012-01-01

    Purpose: The authors present 3 methods of performing pattern recognition on spatiotemporal plots produced by pharyngeal high-resolution manometry (HRM). Method: Classification models, including the artificial neural networks (ANNs) multilayer perceptron (MLP) and learning vector quantization (LVQ), as well as support vector machines (SVM), were…

  8. High-Resolution Land Use and Land Cover Mapping

    USGS Publications Warehouse

    ,

    1999-01-01

    As the Nation?s population grows, quantifying, monitoring, and managing land use becomes increasingly important. The U.S. Geological Survey (USGS) has a long heritage of leadership and innovation in land use and land cover (LULC) mapping that has been the model both nationally and internationally for over 20 years. At present, the USGS is producing high-resolution LULC data for several watershed and urban areas within the United States. This high-resolution LULC mapping is part of an ongoing USGS Land Cover Characterization Program (LCCP). The four components of the LCCP are global (1:2,000,000-scale), national (1:100,000-scale), urban (1:24,000-scale), and special projects (various scales and time periods). Within the urban and special project components, the USGS Rocky Mountain Mapping Center (RMMC) is collecting historical as well as contemporary high-resolution LULC data. RMMC?s high-resolution LULC mapping builds on the heritage and success of previous USGS LULC programs and provides LULC information to meet user requirements.

  9. High-Resolution Nuclear Magnetic Resonance of Solids.

    ERIC Educational Resources Information Center

    Maciel, Gary E.

    1984-01-01

    Examines recent developments in techniques for obtaining high-resolution nuclear magnetic resonance (NMR) spectra on solid samples, discussing the kinds of applications for which these techniques are well suited. Also discusses the characteristics of NMR of solids and generating magnetization for NMR in solids. (JN)

  10. High resolution bone mineral densitometry with a gamma camera

    NASA Technical Reports Server (NTRS)

    Leblanc, A.; Evans, H.; Jhingran, S.; Johnson, P.

    1983-01-01

    A technique by which the regional distribution of bone mineral can be determined in bone samples from small animals is described. The technique employs an Anger camera interfaced to a medical computer. High resolution imaging is possible by producing magnified images of the bone samples. Regional densitometry of femurs from oophorectomised and bone mineral loss.

  11. Workshop on high-resolution, large-acceptance spectrometers

    SciTech Connect

    Zeidman, B.

    1981-01-01

    The purpose of the Workshop on High-Resolution, Large-Acceptance Spectrometers was to provide a means for exchange of information among those actively engaged in the design and construction of these new spectrometers. Thirty-seven papers were prepared for the data base.

  12. High resolution ultraviolet imaging spectrometer for latent image analysis.

    PubMed

    Lyu, Hang; Liao, Ningfang; Li, Hongsong; Wu, Wenmin

    2016-03-21

    In this work, we present a close-range ultraviolet imaging spectrometer with high spatial resolution, and reasonably high spectral resolution. As the transmissive optical components cause chromatic aberration in the ultraviolet (UV) spectral range, an all-reflective imaging scheme is introduced to promote the image quality. The proposed instrument consists of an oscillating mirror, a Cassegrain objective, a Michelson structure, an Offner relay, and a UV enhanced CCD. The finished spectrometer has a spatial resolution of 29.30μm on the target plane; the spectral scope covers both near and middle UV band; and can obtain approximately 100 wavelength samples over the range of 240~370nm. The control computer coordinates all the components of the instrument and enables capturing a series of images, which can be reconstructed into an interferogram datacube. The datacube can be converted into a spectrum datacube, which contains spectral information of each pixel with many wavelength samples. A spectral calibration is carried out by using a high pressure mercury discharge lamp. A test run demonstrated that this interferometric configuration can obtain high resolution spectrum datacube. The pattern recognition algorithm is introduced to analyze the datacube and distinguish the latent traces from the base materials. This design is particularly good at identifying the latent traces in the application field of forensic imaging.

  13. Plant respirometer enables high resolution of oxygen consumption rates

    NASA Technical Reports Server (NTRS)

    Foster, D. L.

    1966-01-01

    Plant respirometer permits high resolution of relatively small changes in the rate of oxygen consumed by plant organisms undergoing oxidative metabolism in a nonphotosynthetic state. The two stage supply and monitoring system operates by a differential pressure transducer and provides a calibrated output by digital or analog signals.

  14. A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

    ERIC Educational Resources Information Center

    Wakabayashi, Fumitaka; Hamada, Kiyohito

    2006-01-01

    Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can…

  15. High Resolution Digital Imaging of Paintings: The Vasari Project.

    ERIC Educational Resources Information Center

    Martinez, Kirk

    1991-01-01

    Describes VASARI (the Visual Art System for Archiving and Retrieval of Images), a project funded by the European Community to show the feasibility of high resolution colormetric imaging directly from paintings. The hardware and software used in the system are explained, storage on optical disks is described, and initial results are reported. (five…

  16. HIGH RESOLUTION RESISTIVITY LEAK DETECTION DATA PROCESSING & EVALUATION MEHTODS & REQUIREMENTS

    SciTech Connect

    SCHOFIELD JS

    2007-10-04

    This document has two purposes: {sm_bullet} Describe how data generated by High Resolution REsistivity (HRR) leak detection (LD) systems deployed during single-shell tank (SST) waste retrieval operations are processed and evaluated. {sm_bullet} Provide the basic review requirements for HRR data when Hrr is deployed as a leak detection method during SST waste retrievals.

  17. Drizzle Measurements Using High Spectral Resolution Lidar and Radar Data

    NASA Astrophysics Data System (ADS)

    Eloranta, Edwin W.

    2016-06-01

    The ratio of millimeter radar and High Spectral Resolution Lidar (HSRL) backscatter are used to determine drizzle rates which are compared to conventional ground based measurements. The robustly calibrated HSRL backscatter cross section provides advantages over measurements made with traditional lidars.

  18. High-Resolution Simulations of Coal Injection in A Gasifier

    SciTech Connect

    Li, Tingwen; Gel, Aytekin; Syamlal, M; Guenther, Chris; Pannala, Sreekanth

    2010-01-01

    This study demonstrates an approach to effectively combine high- and low-resolution simulations for design studies of industrial coal gasifier. The flow-field data from a 10 million cell full-scale simulation of a commercial-scale gasifier were used to construct a reduced configuration to economically study the coal injection in detail. High-resolution numerical simulations of the coal injection were performed using the open-source code MFIX running on a high performance computing system. Effects of grid resolution and numerical discretization scheme on the predicted behavior of coal injection and gasification kinetics were analyzed. Pronounced differences were predicted in the devolatilization and steam gasification rates because of different discretization schemes, implying that a high-order numerical scheme is required to predict well the unsteady gasification process on an adequately resolved grid. Computational costs for simulations of varying resolutions are presented to illustrate the trade-off between the accuracy of solution and the time-to-solution, an important consideration when engineering simulations are used for the design of commercial-scale units.

  19. In vivo high-resolution diffusion tensor imaging of the mouse brain.

    PubMed

    Wu, Dan; Xu, Jiadi; McMahon, Michael T; van Zijl, Peter C M; Mori, Susumu; Northington, Frances J; Zhang, Jiangyang

    2013-12-01

    Diffusion tensor imaging (DTI) of the laboratory mouse brain provides important macroscopic information for anatomical characterization of mouse models in basic research. Currently, in vivo DTI of the mouse brain is often limited by the available resolution. In this study, we demonstrate in vivo high-resolution DTI of the mouse brain using a cryogenic probe and a modified diffusion-weighted gradient and spin echo (GRASE) imaging sequence at 11.7 T. Three-dimensional (3D) DTI of the entire mouse brain at 0.125 mm isotropic resolution could be obtained in approximately 2 h. The high spatial resolution, which was previously only available with ex vivo imaging, enabled non-invasive examination of small structures in the adult and neonatal mouse brains. Based on data acquired from eight adult mice, a group-averaged DTI atlas of the in vivo adult mouse brain with 60 structure segmentations was developed. Comparisons between in vivo and ex vivo mouse brain DTI data showed significant differences in brain morphology and tissue contrasts, which indicate the importance of the in vivo DTI-based mouse brain atlas.

  20. What High School Students Who Are Mildly Mentally Retarded Know about the Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome.

    ERIC Educational Resources Information Center

    Cobb, Hazel B.; Horn, Charles J., Jr.

    Alabama high school students (N=309) with mild mental retardation completed a questionnaire concerning their knowledge, attitudes, and sources of information about human immune deficiency virus/acquired immune deficiency syndrome (HIV/AIDS). Students demonstrated some basic knowledge of HIV/AIDS, and expressed some concern about getting AIDS. They…

  1. High-resolution extended source optical coherence tomography.

    PubMed

    Yu, Xiaojun; Liu, Xinyu; Chen, Si; Luo, Yuemei; Wang, Xianghong; Liu, Linbo

    2015-10-01

    High resolution optical coherence tomography (OCT) is capable of providing detailed tissue microstructures that are critical for disease diagnosis, yet its sensitivity is usually degraded since the system key components are typically not working at their respective center wavelengths. We developed a novel imaging system that achieves enhanced sensitivity without axial resolution degradation by the use of a spectrally encoded extended source (SEES) technique; it allows larger sample power without exceeding the maximum permissible exposure (MPE). In this study, we demonstrate a high-resolution extended source (HRES) OCT system, which is capable of providing a transverse resolution of 4.4 µm and an axial resolution of 2.1 µm in air with the SEES technique. We first theoretically show a sensitivity advantage of 6-dB of the HRES-OCT over that of its point source counterpart using numerical simulations, and then experimentally validate the applicability of the SEES technique to high-resolution OCT (HR-OCT) by comparing the HRES-OCT with an equivalent point-source system. In the HRES-OCT system, a dispersive prism was placed in the infinity space of the sample arm optics to spectrally extend the visual angle (angular subtense) of the light source to 10.3 mrad. This extended source allowed ~4 times larger MPE than its point source counterpart, which results in an enhancement of ~6 dB in sensitivity. Specifically, to solve the unbalanced dispersion between the sample and the reference arm optics, we proposed easy and efficient methods for system calibration and dispersion correction, respectively. With a maximum scanning speed reaching up to 60K A-lines/s, we further conducted imaging experiments with HRES-OCT using the human fingertip in vivo and the swine eye tissues ex vivo. Results demonstrate that the HRES-OCT is able to achieve significantly larger penetration depth than its conventional point source OCT counterpart.

  2. Properties of the Agilkia touchdown site on 67P from ROLIS high resolution imaging

    NASA Astrophysics Data System (ADS)

    Mottola, Stefano; Jaumann, Ralf; Schröder, Stefan; Arnold, Gabriele; Grothues, Hans-Georg; Hamm, Maximilian; Michaelis, Harald; Pelivan, Ivanka; Proffe, Gerrit; Bibring, Jean-Pierre

    2015-04-01

    ROLIS (ROsetta Lander Imaging System) [1,2] is an imager with multispectral capabilities onboard the Rosetta Lander Philae. From its location on the instruments balcony and having a down-looking orientation, ROLIS acquired an imaging sequence of the Agilkia landing site during the descent onto comet 67P/Churyumov-Gerasimenko. These images provide the highest resolution available for the first touch-down site. The aim of the ROLIS experiment is to study the photometric properties, the morphology, the texture and microstructure of the comet's surface in order to understand the processes that control the cometary evolution. ROLIS is a compact CCD imager with a 1k x 1k pixel sensor and a 57° field of view. During the descent it was focused to infinity and acquired panchromatic images. After landing ROLIS was refocused to a nominal distance of 30 cm and performed close-up, multi-spectral imaging of the soil, with help of a 4-color LED illumination device. During the descent, ROLIS acquired images with a cadence of 10 s. Since the exact time of touchdown was not known, and due to storage and uplink capacity limitations, the images were stored in a ring buffer with the capacity of seven images, with the latest image overwriting the oldest. At the moment of touchdown the acquisition sequence was halted, and the last seven images -the ones with the highest resolution- were relayed to the orbiter. The landing occurred on Nov 12, 2014 at 15:34:04 UT. The sun elevation angle of about 30° provided near-ideal conditions for morphological analysis. The image acquired at the highest altitude (70 m) has a footprint of about 70 m and a resolution of 7 cm/pix, whereas the image closest to the surface was acquired at about 10 m altitude and has a resolution of about 1 cm/pix. The high-resolution images acquired just before touchdown reveal a generally smooth and subdued terrain whose characteristics vary over scales of a few tens of meters. A comparatively uniform background made of

  3. High-Resolution Spectroscopy of Some Very Inactive Southern Stars

    NASA Astrophysics Data System (ADS)

    Villarreal, A.; King, J. R.; Soderblom, D. R.; Henry, T. J.

    2001-12-01

    We have obtained high-resolution echelle spectra of a few dozen solar-type stars that an earlier low resolution Ca II H & K survey suggested have modest evels of chromospheric activity. We present Hα -based chromospheric activity measures, binarity information, and Li abundances of the sample. As expected, our spectra: confirm the low levels of chromospheric activity; suggest that these objects are apparently single; indicate the stars have small projected rotational velocities; and yield low photospheric abundances of Li. This work was supported by NSF grant AST-0086576 to JRK.

  4. High-resolution Brillouin analysis of composite materials beams

    NASA Astrophysics Data System (ADS)

    London, Yosef; Antman, Yair; Silbiger, Maayan; Efraim, Liel; Froochzad, Avihay; Adler, Gadi; Levenberg, Eyal; Zadok, Avi

    2015-09-01

    High-resolution Brillouin optical correlation domain analysis of fibers embedded within beams of composite materials is performed with 4 cm resolution and 0.5 MHz sensitivity. Two new contributions are presented. First, analysis was carried out continuously over 30 hours following the production of a beam, observing heating during exothermal curing and buildup of residual strains. Second, the bending stiffness and Young's modulus of the composite beam were extracted based on distributed strain measurements, taken during a static three-point bending experiment. The calculated parameters were used to forecast the beam deflections. The latter were favorably compared against external displacement measurements.

  5. High-resolution (30 m) lunar radar images

    NASA Technical Reports Server (NTRS)

    Zisk, Stanley H.

    1988-01-01

    New high-resolution radar images of the lunar surface are being produced using the Haystack Observatory range-Doppler radar system. The goals are to: investigate the decameter-scale properties of the lunar surface, as an aid in the understanding of the geophysical history of the moon; and to improve the understanding of the mechanisms of planetary radar backscattering, to aid in the interpretation of the coarser-resolution images which were and will be obtained from planetary probe missions and other earth-based observations.

  6. Solutions on high-resolution multiple configuration system sensors

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Ding, Quanxin; Guo, Chunjie; Zhou, Liwei

    2014-11-01

    For aim to achieve an improved resolution in modern image domain, a method of continuous zoom multiple configuration, with a core optics is attempt to establish model by novel principle on energy transfer and high accuracy localization, by which the system resolution can be improved with a level in nano meters. A comparative study on traditional vs modern methods can demonstrate that the dialectical relationship and their balance is important, among Merit function, Optimization algorithms and Model parameterization. The effect of system evaluated criterion that MTF, REA, RMS etc. can support our arguments qualitatively.

  7. High resolution atomic force microscopy of double-stranded RNA

    NASA Astrophysics Data System (ADS)

    Ares, Pablo; Fuentes-Perez, Maria Eugenia; Herrero-Galán, Elías; Valpuesta, José M.; Gil, Adriana; Gomez-Herrero, Julio; Moreno-Herrero, Fernando

    2016-06-01

    Double-stranded (ds) RNA mediates the suppression of specific gene expression, it is the genetic material of a number of viruses, and a key activator of the innate immune response against viral infections. The ever increasing list of roles played by dsRNA in the cell and its potential biotechnological applications over the last decade has raised an interest for the characterization of its mechanical properties and structure, and that includes approaches using Atomic Force Microscopy (AFM) and other single-molecule techniques. Recent reports have resolved the structure of dsDNA with AFM at unprecedented resolution. However, an equivalent study with dsRNA is still lacking. Here, we have visualized the double helix of dsRNA under near-physiological conditions and at sufficient resolution to resolve the A-form sub-helical pitch periodicity. We have employed different high-sensitive force-detection methods and obtained images with similar spatial resolution. Therefore, we show here that the limiting factors for high-resolution AFM imaging of soft materials in liquid medium are, rather than the imaging mode, the force between the tip and the sample and the sharpness of the tip apex.Double-stranded (ds) RNA mediates the suppression of specific gene expression, it is the genetic material of a number of viruses, and a key activator of the innate immune response against viral infections. The ever increasing list of roles played by dsRNA in the cell and its potential biotechnological applications over the last decade has raised an interest for the characterization of its mechanical properties and structure, and that includes approaches using Atomic Force Microscopy (AFM) and other single-molecule techniques. Recent reports have resolved the structure of dsDNA with AFM at unprecedented resolution. However, an equivalent study with dsRNA is still lacking. Here, we have visualized the double helix of dsRNA under near-physiological conditions and at sufficient resolution to

  8. High-resolution imaging of globular cluster cores

    NASA Technical Reports Server (NTRS)

    Weir, N.; Piotto, G.; Djorgovski, S.

    1990-01-01

    An approach based on the maximum entropy method aimed at increasing angular resolution to study globular cluster cores is presented. To perform the image restoration the Gull-Skilling (1989) MEMSYS-3 code for maximum entropy reconstruction of arbitrary data sets was used. This software was recently applied to restoration of ESO images of the R136 object in the core of the 30 Doradus nebula. It was demonstrated that the software made it possible to restore an image at subpixel spatial scales which facilitates the detection of very high-resolution structure in the restored image.

  9. Unmanned Aerial Vehicles Produce High-Resolution Seasonally-Relevant Imagery for Classifying Wetland Vegetation

    NASA Astrophysics Data System (ADS)

    Marcaccio, J. V.; Markle, C. E.; Chow-Fraser, P.

    2015-08-01

    With recent advances in technology, personal aerial imagery acquired with unmanned aerial vehicles (UAVs) has transformed the way ecologists can map seasonal changes in wetland habitat. Here, we use a multi-rotor (consumer quad-copter, the DJI Phantom 2 Vision+) UAV to acquire a high-resolution (< 8 cm) composite photo of a coastal wetland in summer 2014. Using validation data collected in the field, we determine if a UAV image and SWOOP (Southwestern Ontario Orthoimagery Project) image (collected in spring 2010) differ in their classification of type of dominant vegetation type and percent cover of three plant classes: submerged aquatic vegetation, floating aquatic vegetation, and emergent vegetation. The UAV imagery was more accurate than available SWOOP imagery for mapping percent cover of submergent and floating vegetation categories, but both were able to accurately determine the dominant vegetation type and percent cover of emergent vegetation. Our results underscore the value and potential for affordable UAVs (complete quad-copter system < 3,000 CAD) to revolutionize the way ecologists obtain imagery and conduct field research. In Canada, new UAV regulations make this an easy and affordable way to obtain multiple high-resolution images of small (< 1.0 km2) wetlands, or portions of larger wetlands throughout a year.

  10. High-resolution axial MR imaging of tibial stress injuries

    PubMed Central

    2012-01-01

    Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

  11. A high-resolution regional reanalysis for Europe

    NASA Astrophysics Data System (ADS)

    Ohlwein, C.

    2015-12-01

    Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. The regional reanalysis for Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km) and comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by a special soil moisture analysis with boundary conditions provided by ERA-Interim data. The reanalysis data set covers the past 20 years. Extensive evaluation of the reanalysis is performed using independent observations with special emphasis on precipitation and high-impact weather situations indicating a better representation of small scale variability. Further, the evaluation shows an added value of the regional reanalysis with respect to the forcing ERA Interim reanalysis and compared to a pure high-resolution dynamical downscaling approach without data assimilation.

  12. Evaluation of a High-Resolution Regional Reanalysis for Europe

    NASA Astrophysics Data System (ADS)

    Ohlwein, C.; Wahl, S.; Keller, J. D.; Bollmeyer, C.

    2014-12-01

    Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. The regional reanalysis for Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km) and comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by a special soil moisture analysis with boundary conditions provided by ERA-Interim data. The reanalysis data set covers 6 years (2007-2012) and is currently extended to 16 years. Extensive evaluation of the reanalysis is performed using independent observations with special emphasis on precipitation and high-impact weather situations indicating a better representation of small scale variability. Further, the evaluation shows an added value of the regional reanalysis with respect to the forcing ERA Interim reanalysis and compared to a pure high-resolution dynamical downscaling approach without data assimilation.

  13. A High-resolution Reanalysis for the European CORDEX Region

    NASA Astrophysics Data System (ADS)

    Bentzien, Sabrina; Bollmeyer, Christoph; Crewell, Susanne; Friederichs, Petra; Hense, Andreas; Keller, Jan; Keune, Jessica; Kneifel, Stefan; Ohlwein, Christian; Pscheidt, Ieda; Redl, Stephanie; Steinke, Sandra

    2014-05-01

    A High-resolution Reanalysis for the European CORDEX Region Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. The work presented here focuses on the regional reanalysis for Europe with a domain matching the CORDEX-EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km). The COSMO reanalysis system comprises the assimilation of observational data using the existing nudging scheme of COSMO and is complemented by a special soil moisture analysis and boundary conditions given by ERA-interim data. The reanalysis data set currently covers 6 years (2007-2012). The evaluation of the reanalyses is done using independent observations with special emphasis on precipitation and high-impact weather situations. The development and evaluation of the COSMO-based reanalysis for the CORDEX-Euro domain can be seen as a preparation for joint European activities on the development of an ensemble system of regional reanalyses for Europe.

  14. Spatial resolution effects on the assessment of evapotranspiration in olive orchards using high resolution thermal imagery

    NASA Astrophysics Data System (ADS)

    Santos, Cristina; Zarco-Tejada, Pablo J.; Lorite, Ignacio J.; Allen, Richard G.

    2013-04-01

    The use of remote sensing techniques for estimating surface energy balance and water consumption has significantly improved the characterization of the agricultural systems by determining accurate information about crop evapotranspiration and stress, mainly for extensive crops. However the use of these methodologies for woody crops has been low due to the difficulty in the accurate characterization of these crops, mainly caused by a coarse resolution of the imagery provided by the most widely used satellites (such as Landsat 5 and 7). The coarse spatial resolution provided by these satellite sensors aggregates into a single pixel the tree crown, sunlit and shaded soil components. These surfaces can each exhibit huge differences in temperature, albedo and vegetation indexes calculated in the visible, near infrared and short-wave infrared regions. Recent studies have found that the use of energy balance approaches can provide useful results for non-homogeneous crops (Santos et al., 2012) but detailed analysis is required to determine the effect of the spatial resolution and the aggregation of the scene components in these heterogeneous canopies. In this study a comparison between different spatial resolutions has been conducted using images from Landsat 7 (with thermal resolution of 60m) and from an airborne thermal (with resolution of 80 cm) flown over olive orchards at different dates coincident with the Landsat overpass. The high resolution thermal imagery was resampled at different scales to generate images with spatial resolution ranging from 0.8 m up to 120m (thermal resolution for Landsat 5 images). The selection of the study area was made to avoid those areas with missing Landsat 7 data caused by SLC-off gaps. The selected area has a total area of around 2500 ha and is located in Southern Spain, in the province of Malaga. The selected area is mainly cultivated with olive orchards with different crop practices (rainfed, irrigated, high density, young and adult

  15. Compact high-resolution Littrow conical diffraction spectrometer.

    PubMed

    Yang, Qinghua

    2016-06-20

    This paper presents a compact high-resolution Littrow conical diffraction spectrometer (LCDS) that includes an echelle grating for horizontally dispersing the incident light beam into several high diffraction orders, a prism for vertically separating the overlapping diffraction orders, and a shared focusing lens used for both the incident and dispersed beams. The unique design of the optics enables the LCDS to give high dispersion on the detector without requiring a large field of view and, therefore, to achieve the benefits of high spectral resolution and compactness. The use of the Littrow conical diffraction coupled with the shared focusing lens makes the LCDS more compact. The formulas of the footprint of the dispersed spectra are derived, and the numerical simulation is given. The design calculations for application of the LCDS to an optical coherence tomography system are illustrated by an example.

  16. High-resolution structure of the native histone octamer

    SciTech Connect

    Wood, Christopher M.; Nicholson, James M.; Lambert, Stanley J.; Chantalat, Laurent; Reynolds, Colin D.; Baldwin, John P.

    2005-06-01

    The high-resolution (1.90 Å) model of the native histone octamer allows structural comparisons to be made with the nucleosome-core particle, along with an identification of a likely core-histone binding site. Crystals of native histone octamers (H2A–H2B)–(H4–H3)–(H3′–H4′)–(H2B′–H2A′) from chick erythrocytes in 2 M KCl, 1.35 M potassium phosphate pH 6.9 diffract X-rays to 1.90 Å resolution, yielding a structure with an R{sub work} value of 18.7% and an R{sub free} of 22.2%. The crystal space group is P6{sub 5}, the asymmetric unit of which contains one complete octamer. This high-resolution model of the histone-core octamer allows further insight into intermolecular interactions, including water molecules, that dock the histone dimers to the tetramer in the nucleosome-core particle and have relevance to nucleosome remodelling. The three key areas analysed are the H2A′–H3–H4 molecular cluster (also H2A–H3′–H4′), the H4–H2B′ interaction (also H4′–H2B) and the H2A′–H4 β-sheet interaction (also H2A–H4′). The latter of these three regions is important to nucleosome remodelling by RNA polymerase II, as it is shown to be a likely core-histone binding site, and its disruption creates an instability in the nucleosome-core particle. A majority of the water molecules in the high-resolution octamer have positions that correlate to similar positions in the high-resolution nucleosome-core particle structure, suggesting that the high-resolution octamer model can be used for comparative studies with the high-resolution nucleosome-core particle.

  17. High-resolution polarization sensitive OCT for ocular imaging in rodents

    NASA Astrophysics Data System (ADS)

    Fialová, Stanislava; Rauscher, Sabine; Gröger, Marion; Pircher, Michael; Hitzenberger, Christoph K.; Baumann, Bernhard

    2015-03-01

    A new high-resolution polarization sensitive optical coherence tomography system was developed for imaging rodent retina. Various light-tissue interactions such as birefringence and depolarization can change the polarization state of light. In the eye, there are several tissues that have these properties, for example retinal pigment epithelium (depolarization) and sclera (birefringence). These layers play key roles in diseases like age-related macular degeneration or glaucoma. Animal models are an important component for understanding disease pathogenesis. The gold standard for the evaluation of preclinical experiments is histology, which is an invasive and terminal procedure. Since OCT is non-invasive, it has the potential to be an alternative to histology with the benefit of long-term study of the disease progression in the same animal. In this study, a superluminescent diode with spectrum width 100 nm and mean wavelength 840 nm is used as a light source in order to enable high axial resolution. Spectrometers are custom built to enable high imaging speed that allows acquiring 3D data sets with 1024x200x1536 voxels in 3.44 s. From the acquired data, images displaying phase retardation induced by birefringence and orientation of birefringent axis were calculated. In first measurements, we were able to identify the RPE-choroid complex (depolarization effect) and the sclera (strong birefringence) in the retina of Long-Evans and Sprague-Dawley rats. Our preliminary results demonstrate the feasibility of the system for high speed/resolution imaging of the rodent retina. This is useful for longitudinal studies of disease models of retinal disease in rats and mice

  18. Bendable X-ray Optics for High Resolution Imaging

    NASA Technical Reports Server (NTRS)

    Gubarev, M.; Ramsey, B.; Kilaru, K.; Atkins, C.; Broadway, D.

    2014-01-01

    Current state-of the-art for x-ray optics fabrication calls for either the polishing of massive substrates into high-angular-resolution mirrors or the replication of thin, lower-resolution, mirrors from perfectly figured mandrels. Future X-ray Missions will require a change in this optics fabrication paradigm in order to achieve sub-arcsecond resolution in light-weight optics. One possible approach to this is to start with perfectly flat, light-weight surface, bend it into a perfect cone, form the desired mirror figure by material deposition, and insert the resulting mirror into a telescope structure. Such an approach is currently being investigated at MSFC, and a status report will be presented detailing the results of finite element analyses, bending tests and differential deposition experiments.

  19. Advances toward high spectral resolution quantum X-ray calorimetry

    NASA Technical Reports Server (NTRS)

    Moseley, S. H.; Kelley, R. L.; Schoelkopf, R. J.; Szymkowiak, A. E.; Mccammon, D.

    1988-01-01

    Thermal detectors for X-ray spectroscopy combining high spectral resolution and quantum efficiency have been developed. These microcalorimeters measure the energy released in the absorption of a single photon by sensing the rise in temperature of a small absorbing structure. The ultimate energy resolution of such a device is limited by the thermodynamic power fluctuations in the thermal link between the calorimeter and isothermal bath and can in principle be made as low as 1 eV. The performance of a real device is degraded due to noise contributions such as excess 1/f noise in the thermistor and incomplete conversion of energy into phonons. The authors report some recent advances in thermometry, X-ray absorption and thermalization, fabrication techniques, and detector optimization in the presence of noise. These improvements have resulted in a device with a spectral resolution of 17 eV FWHM, measured at 6 keV.

  20. Very High Resolution Climate Modelling in Northern Russia

    NASA Astrophysics Data System (ADS)

    Stendel, M.; Christensen, J. H.

    2009-04-01

    Simulations with global climate models (GCMs) clearly indicate that major climate changes for the Arctic can be expected during the 21st century. Already now, there are substantial changes in sea-ice extent and thickness and a considerable increase in air temperature in several regions. Contemporary GCMs are unable to give a realistic representation of the climate and climate change in regions with steep orography, due to their coarse resolution. But even relatively high resolution regional climate models (RCMs) fail in this respect. We have therefore conducted a transient simulation with the newest version of the HIRHAM RCM, covering the period 1958-2001 over a region in northeast European Russia, including the Ural Mountains, with the unprecedented horizontal resolution of 4 km. For this simulation, a double downscaling procedure was applied. Average and extreme values will be discussed, and a comparison of subsurface temperatures to a set of observations from the region will be presented.

  1. High Resolution X-ray Spectroscopy of SN 1006

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2005-06-01

    I discuss the high resolution XMM-Newton Reflection Grating Spectrometer (RGS) spectrum of SN 1006. SN 1006 is one of the best examples of a supernova remnant that is far out of ionization equilibrium. Moreover, optical, UV and X-ray data indicate that it is also out of temperature equilibrium. I discuss the X-ray evidence for this. In addition I discuss the lower resolution RGS spectrum of the eastern rim of SN 1006. Despite the lower resolution, the spectrum contains significant evidence for an asymmetric expansion velocity. Two likely solutions fit the O VII triplet. One with no significant thermal broadening and a shell velocity of ~ 6500 km s-1, and one with significant broadening and a shell velocity of 9500 km s -1. The first solution seems the most plausible, as it is consistent with radio expansion measurements, which suggests a decelerated shell.

  2. Broadband high resolution X-ray spectral analyzer

    DOEpatents

    Silver, E.H.; Legros, M.; Madden, N.W.; Goulding, F.; Landis, D.

    1998-07-07

    A broad bandwidth high resolution X-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces X-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available X-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for X-ray microanalysis or in research applications such as laboratory and astrophysical X-ray and particle spectroscopy. 6 figs.

  3. Broadband high resolution X-ray spectral analyzer

    DOEpatents

    Silver, Eric H.; Legros, Mark; Madden, Norm W.; Goulding, Fred; Landis, Don

    1998-01-01

    A broad bandwidth high resolution x-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces x-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available x-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for x-ray microanalysis or in research applications such as laboratory and astrophysical x-ray and particle spectroscopy.

  4. High Resolution Absorption Spectroscopy using Externally Dispersed Interferometry

    SciTech Connect

    Edelstein, J; Erskine, D J

    2005-07-06

    We describe the use of Externally Dispersed Interferometry (EDI) for high-resolution absorption spectroscopy. By adding a small fixed-delay interferometer to a dispersive spectrograph, a precise fiducial grid in wavelength is created over the entire spectrograph bandwidth. The fiducial grid interacts with narrow spectral features in the input spectrum to create a moire pattern. EDI uses the moire pattern to obtain new information about the spectra that is otherwise unavailable, thereby improving spectrograph performance. We describe the theory and practice of EDI instruments and demonstrate improvements in the spectral resolution of conventional spectrographs by a factor of 2 to 6. The improvement of spectral resolution offered by EDI can benefit space instruments by reducing spectrograph size or increasing instantaneous bandwidth.

  5. Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry

    PubMed Central

    Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

    2011-01-01

    In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000–15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert’s visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition. PMID:21544266

  6. High-resolution imaging microchannel plate detector for EUV spectrometry

    NASA Astrophysics Data System (ADS)

    Bannister, Nigel P.; Lapington, Jonathan S.; Barstow, Martin A.; Fraser, George W.; Sanderson, B. S.; Tandy, J. A.; Pearson, James F.; Spragg, J. E.

    2000-12-01

    We describe the development of an imaging microchannel plate detector for a new class of high resolution EUV spectrometer. The detector incorporates a front MCP coated with a CsI photocathode to enhance quantum efficiency, while the rear MCP, supplied by Photonis SAS for a European Space Agency Technology Research Program, represents one of the first uses of a 6 micron pore device in astronomy. The detector uses a unique design of charge division anode, the Vernier readout, enabling it to deliver a spatial resolution better than 15 microns FWHM. The detector forms an integral component of J- PEX, a sounding rocket EUV spectrometer operating at near- normal incidence, using multilayer coated gratings to deliver a resolution and effective area 10 times that of EUVE in the 225 - 245 angstrom band.

  7. Tuning and scanning control system for high resolution alexandrite lasers

    NASA Technical Reports Server (NTRS)

    Smith, James C.; Schwemmer, Geary K.

    1988-01-01

    An alexandrite laser is spectrally narrowed and tuned by the use of three optical elements. Each element provides a successively higher degree of spectral resolution. The digitally controlled tuning and scanning control servo system simultaneously positions all three optical elements to provide continuous high resolution laser spectral tuning. The user may select manual, single, or continuous modes of automated scanning of ranges up to 3.00/cm and at scan rates up to 3.85/cm/min. Scanning over an extended range of up to 9.999/cm may be achieved if the highest resolution optic is removed from the system. The control system is also capable of being remotely operated by another computer or controller via standard RS-232 serial data link.

  8. High energy, high resolution X-ray optics

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.; Joy, Marshall; Kahn, Steven

    1990-01-01

    The scientific goals of X-ray astronomy are considered to evaluate the relative advantages of using classical Wolter-1 optics or using a different approach. The portion of the X-ray band over 10 keV is unexploited in the present X-ray optics technology, and focussing in this portion of the band is crucial because nonfocussed experiments are background limited. The basic design of 'hard' X-ray optics is described theoretically emphasizing the very small angles of incidence in the grazing-incidence optics. Optimization of the signal-to-noise ratio is found to occur at a finite angular resolution. In real applications, the effective area reduced by the efficiency of the two reflections is 80 percent at energies up to 40 keV, and the quality of the reflecting surface can be monitored to minimize scattering. Focussing optics are found to offer improvements in signal-to-noise as well as more effective scientific return because microelectronic focal-plane technology is employed.

  9. High resolution dissociative electron attachment to gas phase adenine

    SciTech Connect

    Huber, D.; Beikircher, M.; Denifl, S.; Zappa, F.; Matejcik, S.; Bacher, A.; Grill, V.; Maerk, T. D.; Scheier, P.

    2006-08-28

    The dissociative electron attachment to the gas phase nucleobase adenine is studied using two different experiments. A double focusing sector field mass spectrometer is utilized for measurements requiring high mass resolution, high sensitivity, and relative ion yields for all the fragment anions and a hemispherical electron monochromator instrument for high electron energy resolution. The negative ion mass spectra are discussed at two different electron energies of 2 and 6 eV. In contrast to previous gas phase studies a number of new negative ions are discovered in the mass spectra. The ion efficiency curves for the negative ions of adenine are measured for the electron energy range from about 0 to 15 eV with an electron energy resolution of about 100 meV. The total anion yield derived via the summation of all measured fragment anions is compared with the total cross section for negative ion formation measured recently without mass spectrometry. For adenine the shape of the two cross section curves agrees well, taking into account the different electron energy resolutions; however, for thymine some peculiar differences are observed.

  10. High resolution three-dimensional prostate ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Li, Yinbo; Patil, Abhay; Hossack, John A.

    2006-03-01

    This work reports on the application of ultrasound elastography to prostate cancer detection using a high resolution three-dimensional (3D) ultrasound imaging system. The imaging was performed at a relatively high frequency (14 MHz), yielding very fine resolution that is optimal for prostate ultrasound imaging. The fine resolution achieved aids in locating smaller lesions than are normally detectable. Elasticity was measured with a quantitative and automatically controlled "Synthetic Digital Rectal Examination (SDRE)" wherein a smoothly increasing force was applied by injecting water, controlled by an electronic syringe pump, into a latex cover over the transrectal transducer. The lesion identified as stiffened tissue was visually enhanced by colorizing and superimposing it over the conventional B-mode image. Experimental results using a tissue-mimicking phantom demonstrated that the reconstruction accuracy of the I-Beam transducer resulted in less than 15% volumetric error. Thus, this high resolution 3D prostate elastography is possible and may provide reliable and accurate determination of the size and the location of cancers, which may result in improved specificity and sensitivity of cancer detection.

  11. Photoacoustic lymphatic imaging with high spatial-temporal resolution

    NASA Astrophysics Data System (ADS)

    Martel, Catherine; Yao, Junjie; Huang, Chih-Hsien; Zou, Jun; Randolph, Gwendalyn J.; Wang, Lihong V.

    2014-11-01

    Despite its critical function in coordinating the egress of inflammatory and immune cells out of tissues and maintaining fluid balance, the causative role of lymphatic network dysfunction in pathological settings is still understudied. Engineered-animal models and better noninvasive high spatial-temporal resolution imaging techniques in both preclinical and clinical studies will help to improve our understanding of different lymphatic-related pathologic disorders. Our aim was to take advantage of our newly optimized noninvasive wide-field fast-scanning photoacoustic (PA) microcopy system to coordinately image the lymphatic vasculature and its flow dynamics, while maintaining high resolution and detection sensitivity. Here, by combining the optical-resolution PA microscopy with a fast-scanning water-immersible microelectromechanical system scanning mirror, we have imaged the lymph dynamics over a large field-of-view, with high spatial resolution and advanced detection sensitivity. Depending on the application, lymphatic vessels (LV) were spectrally or temporally differentiated from blood vessels. Validation experiments were performed on phantoms and in vivo to identify the LV. Lymphatic flow dynamics in nonpathological and pathological conditions were also visualized. These results indicate that our newly developed PA microscopy is a promising tool for lymphatic-related biological research.

  12. Photoacoustic lymphatic imaging with high spatial-temporal resolution.

    PubMed

    Martel, Catherine; Yao, Junjie; Huang, Chih-Hsien; Zou, Jun; Randolph, Gwendalyn J; Wang, Lihong V

    2014-11-01

    Despite its critical function in coordinating the egress of inflammatory and immune cells out of tissues and maintaining fluid balance, the causative role of lymphatic network dysfunction in pathological settings is still understudied. Engineered-animal models and better noninvasive high spatial-temporal resolution imaging techniques in both preclinical and clinical studies will help to improve our understanding of different lymphatic-related pathologic disorders. Our aim was to take advantage of our newly optimized noninvasive wide-field fast-scanning photoacoustic (PA) microcopy system to coordinately image the lymphatic vasculature and its flow dynamics, while maintaining high resolution and detection sensitivity. Here, by combining the optical-resolution PA microscopy with a fast-scanning water-immersible microelectromechanical system scanning mirror, we have imaged the lymph dynamics over a large field-of-view, with high spatial resolution and advanced detection sensitivity. Depending on the application, lymphatic vessels (LV) were spectrally or temporally differentiated from blood vessels. Validation experiments were performed on phantoms and in vivo to identify the LV. Lymphatic flow dynamics in nonpathological and pathological conditions were also visualized. These results indicate that our newly developed PA microscopy is a promising tool for lymphatic-related biological research.

  13. High-resolution Imaging Techniques for the Assessment of Osteoporosis

    PubMed Central

    Krug, Roland; Burghardt, Andrew J.; Majumdar, Sharmila; Link, Thomas M.

    2010-01-01

    Synopsis The importance of assessing the bone’s microarchitectural make-up in addition to its mineral density in the context of osteoporosis has been emphasized in a number of publications. The high spatial resolution required to resolve the bone’s microstructure in a clinically feasible scan time is challenging. Currently, the best suited modalities meeting these requirements in vivo are high-resolution peripheral quantitative imaging (HR-pQCT) and magnetic resonance imaging (MRI). Whereas HR-pQCT is limited to peripheral skeleton regions like the wrist and ankle, MRI can also image other sites like the proximal femur but usually with lower spatial resolution. In addition Multidetector-CT has been used for high-resolution imaging of trabecular bone structure, however, the radiation dose is a limiting factor. This article provides an overview of the different modalities, technical requirements and recent developments in this emerging field. Details regarding imaging protocols as well as image post-processing methods for bone structure quantification are discussed. PMID:20609895

  14. High-Resolution Angioscopic Imaging During Endovascular Neurosurgery

    PubMed Central

    McVeigh, Patrick Z.; Sacho, Raphael; Weersink, Robert A.; Pereira, Vitor M.; Kucharczyk, Walter; Seibel, Eric J.; Wilson, Brian C.

    2014-01-01

    BACKGROUND: Endoluminal optical imaging, or angioscopy, has not seen widespread application during neurointerventional procedures, largely as a result of the poor imaging resolution of existing angioscopes. Scanning fiber endoscopes (SFEs) are a novel endoscopic platform that allows high-resolution video imaging in an ultraminiature form factor that is compatible with currently used distal access endoluminal catheters. OBJECTIVE: To test the feasibility and potential utility of high-resolution angioscopy with an SFE during common endovascular neurosurgical procedures. METHODS: A 3.7-French SFE was used in a porcine model system to image endothelial disruption, ischemic stroke and mechanical thrombectomy, aneurysm coiling, and flow-diverting stent placement. RESULTS: High-resolution, video-rate imaging was shown to be possible during all of the common procedures tested and provided information that was complementary to standard fluoroscopic imaging. SFE angioscopy was able to assess novel factors such as aneurysm base coverage fraction and side branch patency, which have previously not been possible to determine with conventional angiography. CONCLUSION: Endovascular imaging with an SFE provides important information on factors that cannot be assessed fluoroscopically and is a novel platform on which future neurointerventional techniques may be based because it allows for periprocedural inspection of the integrity of the vascular system and the deployed devices. In addition, it may be of diagnostic use for inspecting the vascular wall and postprocedure device evaluation. ABBREVIATIONS: CFB, coherent fiber bundle F, French SFE, scanning fiber endoscope PMID:24762703

  15. High-resolution schemes for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Harten, A.

    1982-01-01

    A class of new explicit second order accurate finite difference schemes for the computation of weak solutions of hyperbolic conservation laws is presented. These highly nonlinear schemes are obtained by applying a nonoscillatory first order accurae scheme to an appropriately modified flux function. The so derived second order accurate schemes achieve high resolution while preserving the robustness of the original nonoscillatory first order accurate scheme.

  16. Accelerated High-Resolution Differential Ion Mobility Separations Using Hydrogen

    PubMed Central

    Shvartsburg, Alexandre A.; Smith, Richard D.

    2011-01-01

    The resolving power of differential ion mobility spectrometry (FAIMS) was dramatically increased recently by carrier gases comprising up to 75% He or various vapors, enabling many new applications. However, the need for resolution of complex mixtures is virtually open-ended and many topical analyses demand yet finer separations. Also, the resolving power gains are often at the expense of speed, in particular making high-resolution FAIMS incompatible with online liquid-phase separations. Here, we report FAIMS employing hydrogen, specifically in mixtures with N2 containing up to 90% H2. Such compositions raise the mobilities of all ions and thus the resolving power beyond that previously feasible, while avoiding the electrical breakdown inevitable in He-rich mixtures. The increases in resolving power and ensuing peak resolution are especially significant at H2 fractions above ~50%. Higher resolution can be exchanged for acceleration of the analyses by up to ~4 times, at least. For more mobile species such as multiply-charged peptides, this exchange is presently forced by the constraints of existing FAIMS devices, but future designs optimized for H2 should consistently improve resolution for all analytes. PMID:22074292

  17. Performance characterization of a new high resolution PET scintillation detector

    PubMed Central

    Foudray, A M K; Olcott, P D

    2013-01-01

    Performance of a new high resolution PET detection concept is presented. In this new concept, annihilation radiation enters the scintillator detectors edge-on. Each detector module comprises two 8 × 8 LYSO scintillator arrays of 0.91 × 0.91 × 1 mm3 crystals coupled to two position-sensitive avalanche photodiodes (PSAPDs) mounted on a flex circuit. Appropriate crystal segmentation allows the recording of all three spatial coordinates of the interaction(s) simultaneously with submillimeter resolution. We report an average energy resolution of 14.6 ± 1.7% for 511 keV photons at FWHM. Coincident time resolution was determined to be 2.98 ± 0.13 ns FWHM on average. The coincidence point spread function (PSF) has an average FWHM of 0.837 ± 0.049 mm (using a 500 μm spherical source) and is uniform across the arrays. Both PSF and coincident time resolution degrade when Compton interactions are included in the data. Different blurring factors were evaluated theoretically, resulting in a calculated PSF of 0.793 mm, in good agreement with the measured value. PMID:20844332

  18. Accelerated high-resolution differential ion mobility separations using hydrogen.

    PubMed

    Shvartsburg, Alexandre A; Smith, Richard D

    2011-12-01

    The resolving power of differential ion mobility spectrometry (FAIMS) was dramatically increased recently by carrier gases comprising up to 75% He or various vapors, enabling many new applications. However, the need for resolution of complex mixtures is virtually open-ended and many topical analyses demand yet finer separations. Also, the resolving power gains are often at the expense of speed, in particular making high-resolution FAIMS poorly compatible with online liquid-phase separations. Here, we report FAIMS employing hydrogen, specifically in mixtures with N(2) containing up to 90% H(2). Such compositions raise the mobilities of all ions and thus the resolving power beyond that previously feasible, while avoiding the electrical breakdown inevitable in He-rich mixtures. The increases in resolving power and ensuing peak resolution are especially significant at H(2) fractions above ~50%. Higher resolution can be exchanged for acceleration of the analyses by up to ~4 times. For more mobile species such as multiply charged peptides, this exchange is presently forced by the constraints of existing FAIMS devices, but future designs optimized for H(2) should consistently improve resolution for all analytes.

  19. A Combined Multiple-SLED Broadband Light Source at 1300 nm for High Resolution Optical Coherence Tomography

    PubMed Central

    Wang, Hui; Jenkins, Michael W.; Rollins, Andrew M.

    2013-01-01

    We demonstrate a compact, inexpensive, and reliable fiber–coupled light source with broad bandwidth and sufficient power at 1300 nm for high resolution optical coherence tomography (OCT) imaging in real-time applications. By combining four superluminescent diodes (SLEDs) with different central wavelengths, the light source has a bandwidth of 145 nm centered at 1325 nm with over 10 mW of power. OCT images of an excised stage 30 embryonic chick heart acquired with our combined SLED light source (<5 μm axial resolution in tissue) are compared with images obtained with a single SLED source (~10 μm axial resolution in tissue). The high resolution OCT system with the combined SLED light source provides better image quality (smaller speckle noise) and a greater ability to observe fine structures in the embryonic heart. PMID:24347689

  20. A Combined Multiple-SLED Broadband Light Source at 1300 nm for High Resolution Optical Coherence Tomography.

    PubMed

    Wang, Hui; Jenkins, Michael W; Rollins, Andrew M

    2008-04-01

    We demonstrate a compact, inexpensive, and reliable fiber-coupled light source with broad bandwidth and sufficient power at 1300 nm for high resolution optical coherence tomography (OCT) imaging in real-time applications. By combining four superluminescent diodes (SLEDs) with different central wavelengths, the light source has a bandwidth of 145 nm centered at 1325 nm with over 10 mW of power. OCT images of an excised stage 30 embryonic chick heart acquired with our combined SLED light source (<5 μm axial resolution in tissue) are compared with images obtained with a single SLED source (~10 μm axial resolution in tissue). The high resolution OCT system with the combined SLED light source provides better image quality (smaller speckle noise) and a greater ability to observe fine structures in the embryonic heart.