A multi-directional backlight for a wide-angle, glasses-free three-dimensional display.

PubMed

Fattal, David; Peng, Zhen; Tran, Tho; Vo, Sonny; Fiorentino, Marco; Brug, Jim; Beausoleil, Raymond G

2013-03-21

Multiview three-dimensional (3D) displays can project the correct perspectives of a 3D image in many spatial directions simultaneously. They provide a 3D stereoscopic experience to many viewers at the same time with full motion parallax and do not require special glasses or eye tracking. None of the leading multiview 3D solutions is particularly well suited to mobile devices (watches, mobile phones or tablets), which require the combination of a thin, portable form factor, a high spatial resolution and a wide full-parallax view zone (for short viewing distance from potentially steep angles). Here we introduce a multi-directional diffractive backlight technology that permits the rendering of high-resolution, full-parallax 3D images in a very wide view zone (up to 180 degrees in principle) at an observation distance of up to a metre. The key to our design is a guided-wave illumination technique based on light-emitting diodes that produces wide-angle multiview images in colour from a thin planar transparent lightguide. Pixels associated with different views or colours are spatially multiplexed and can be independently addressed and modulated at video rate using an external shutter plane. To illustrate the capabilities of this technology, we use simple ink masks or a high-resolution commercial liquid-crystal display unit to demonstrate passive and active (30 frames per second) modulation of a 64-view backlight, producing 3D images with a spatial resolution of 88 pixels per inch and full-motion parallax in an unprecedented view zone of 90 degrees. We also present several transparent hand-held prototypes showing animated sequences of up to six different 200-view images at a resolution of 127 pixels per inch.

Distant Supernova Remnant Imaged by Chandra's High Resolution Camera

NASA Astrophysics Data System (ADS)

1999-09-01

The High Resolution Camera (HRC), one of the two X-ray cameras on NASA's Chandra X-ray Observatory, was placed into the focus for the first time on Monday, August 30. The first target was LMC X-1, a point-like source of X rays in the Large Magellanic Cloud. The Large Magellanic Cloud, a companion galaxy to the Milky Way, is 160,000 light years from Earth. After checking the focus with LMC X-1, Chandra observed N132D, a remnant of an exploded star in the Large Magellanic Cloud. "These were preliminary test observations," emphasized Dr. Stephen Murray, of the Harvard-Smithsonian Center for Astrophysics, principal investigator for the High Resolution Camera. "But we are very pleased with the results. All indications are that the HRC will produce X-ray images of unprecedented clarity." The N132D image shows a highly structured remnant, or shell, of 10-million-degree gas that is 80 light years across. Such a shell in the vicinity of the Sun would encompass more than fifty nearby stars. The amount of material in the N132D hot gas remnant is equal to that of 600 suns. The N132D supernova remnant appears to be colliding with a giant molecular cloud, which produces the brightening on the southern rim of the remnant. The molecular cloud, visible with a radio telescope, has the mass of 300,000 suns. The relatively weak x-radiation on the upper left shows that the shock wave is expanding into a less dense region on the edge of the molecular cloud. A number of small circular structures are visible in the central regions and a hint of a large circular loop can be seen in the upper part of the remnant. Whether the peculiar shape of the supernova remnant can be fully explained in terms of these effects, or whether they point to a peculiar cylindrically shaped explosion remains to be seen. -more- "The image is so rich in structure that it will take a while to sort out what is really going on," Murray said. "It could be multiple supernovas, or absorbing clouds in the vicinity of the 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

A new implementation of full resolution SBAS-DInSAR processing chain for the effective monitoring of structures and infrastructures

NASA Astrophysics Data System (ADS)

Bonano, Manuela; Buonanno, Sabatino; Ojha, Chandrakanta; Berardino, Paolo; Lanari, Riccardo; Zeni, Giovanni; Manunta, Michele

2017-04-01

The advanced DInSAR technique referred to as Small BAseline Subset (SBAS) algorithm has already largely demonstrated its effectiveness to carry out multi-scale and multi-platform surface deformation analyses relevant to both natural and man-made hazards. Thanks to its capability to generate displacement maps and long-term deformation time series at both regional (low resolution analysis) and local (full resolution analysis) spatial scales, it allows to get more insights on the spatial and temporal patterns of localized displacements relevant to single buildings and infrastructures over extended urban areas, with a key role in supporting risk mitigation and preservation activities. The extensive application of the multi-scale SBAS-DInSAR approach in many scientific contexts has gone hand in hand with new SAR satellite mission development, characterized by different frequency bands, spatial resolution, revisit times and ground coverage. This brought to the generation of huge DInSAR data stacks to be efficiently handled, processed and archived, with a strong impact on both the data storage and the computational requirements needed for generating the full resolution SBAS-DInSAR results. Accordingly, innovative and effective solutions for the automatic processing of massive SAR data archives and for the operational management of the derived SBAS-DInSAR products need to be designed and implemented, by exploiting the high efficiency (in terms of portability, scalability and computing performances) of the new ICT methodologies. In this work, we present a novel parallel implementation of the full resolution SBAS-DInSAR processing chain, aimed at investigating localized displacements affecting single buildings and infrastructures relevant to very large urban areas, relying on different granularity level parallelization strategies. The image granularity level is applied in most steps of the SBAS-DInSAR processing chain and exploits the multiprocessor systems with distributed memory. Moreover, in some processing steps very heavy from the computational point of view, the Graphical Processing Units (GPU) are exploited for the processing of blocks working on a pixel-by-pixel basis, requiring strong modifications on some key parts of the sequential full resolution SBAS-DInSAR processing chain. GPU processing is implemented by efficiently exploiting parallel processing architectures (as CUDA) for increasing the computing performances, in terms of optimization of the available GPU memory, as well as reduction of the Input/Output operations on the GPU and of the whole processing time for specific blocks w.r.t. the corresponding sequential implementation, particularly critical in presence of huge DInSAR datasets. Moreover, to efficiently handle the massive amount of DInSAR measurements provided by the new generation SAR constellations (CSK and Sentinel-1), we perform a proper re-design strategy aimed at the robust assimilation of the full resolution SBAS-DInSAR results into the web-based Geonode platform of the Spatial Data Infrastructure, thus allowing the efficient management, analysis and integration of the interferometric results with different data sources.

Improvement of resolution in full-view linear-array photoacoustic computed tomography using a novel adaptive weighting method

NASA Astrophysics Data System (ADS)

Omidi, Parsa; Diop, Mamadou; Carson, Jeffrey; Nasiriavanaki, Mohammadreza

2017-03-01

Linear-array-based photoacoustic computed tomography is a popular methodology for deep and high resolution imaging. However, issues such as phase aberration, side-lobe effects, and propagation limitations deteriorate the resolution. The effect of phase aberration due to acoustic attenuation and constant assumption of the speed of sound (SoS) can be reduced by applying an adaptive weighting method such as the coherence factor (CF). Utilizing an adaptive beamforming algorithm such as the minimum variance (MV) can improve the resolution at the focal point by eliminating the side-lobes. Moreover, invisibility of directional objects emitting parallel to the detection plane, such as vessels and other absorbing structures stretched in the direction perpendicular to the detection plane can degrade resolution. In this study, we propose a full-view array level weighting algorithm in which different weighs are assigned to different positions of the linear array based on an orientation algorithm which uses the histogram of oriented gradient (HOG). Simulation results obtained from a synthetic phantom show the superior performance of the proposed method over the existing reconstruction methods.

Supernova Cosmology Project

Science.gov Websites

(note that the arXiv.org version lacks the full-resolution figures) The SCP "Union" SN Ia Matrix Description Covariance Matrix with Systematics Description Full Table of All SNe Description

[Development of an original computer program FISHMet: use for molecular cytogenetic diagnosis and genome mapping by fluorescent in situ hybridization (FISH)].

PubMed

Iurov, Iu B; Khazatskiĭ, I A; Akindinov, V A; Dovgilov, L V; Kobrinskiĭ, B A; Vorsanova, S G

2000-08-01

Original software FISHMet has been developed and tried for improving the efficiency of diagnosis of hereditary diseases caused by chromosome aberrations and for chromosome mapping by fluorescent in situ hybridization (FISH) method. The program allows creation and analysis of pseudocolor chromosome images and hybridization signals in the Windows 95 system, allows computer analysis and editing of the results of pseudocolor hybridization in situ, including successive imposition of initial black-and-white images created using fluorescent filters (blue, green, and red), and editing of each image individually or of a summary pseudocolor image in BMP, TIFF, and JPEG formats. Components of image computer analysis system (LOMO, Leitz Ortoplan, and Axioplan fluorescent microscopes, COHU 4910 and Sanyo VCB-3512P CCD cameras, Miro-Video, Scion LG-3 and VG-5 image capture maps, and Pentium 100 and Pentium 200 computers) and specialized software for image capture and visualization (Scion Image PC and Video-Cup) have been used with good results in the study.

Lava and Snow on Klyuchevskaya Volcano [high res

NASA Image and Video Library

2013-09-20

IDL TIFF file This false-color (shortwave infrared, near infrared, green) satellite image reveals an active lava flow on the western slopes of Klyuchevskaya Volcano. Klyuchevskaya is one of several active volcanoes on the Kamchatka Peninsula in far eastern Russia. The lava flow itself is bright red. Snow on Klyuchevskaya and nearby mountains is cyan, while bare ground and volcanic debris is gray or brown. Vegetation is green. The image was collected by Landsat 8 on September 9, 2013. NASA Earth Observatory image by Jesse Allen and Robert Simmon, using Instrument: Landsat 8 - OLI More info: 1.usa.gov/1evspH7 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

EVALUATION OF FULL-FIELD ELECTRORETINOGRAM REDUCTIONS AFTER OCRIPLASMIN TREATMENT

PubMed Central

Benz, Matthew S.; Miller, Daniel M.; Antoszyk, Andrew N.; Markoff, Joseph; Kozma, Petra; Meunier, Esmeralda; Sergott, Robert C.

2018-01-01

Purpose: To explore a possible association between full-field electroretinograms with vitreomacular adhesion resolution and best-corrected visual acuity as part of the prospective, randomized, double-masked, sham-controlled Ocriplasmin for Treatment for Symptomatic Vitreomacular Adhesion Including Macular Hole (OASIS) trial studying ocriplasmin. Methods: The ERG substudy enrolled 62 of 220 OASIS subjects (randomized 2:1) and analyzed full-field electroretinograms and their association with both vitreomacular adhesion resolution and best-corrected visual acuity from baseline through Month 24. Electroretinogram reductions were defined as acute full-field electroretinogram reductions in amplitude of ≥40% from baseline occurring at postinjection Day 7 or Day 28. Results: In the ocriplasmin group, 16/40 (40%) subjects developed ERG reductions, compared to 1/21 (4.8%) in the sham group; 13/16 (81.3%) and 1/1 (100%) resolved by study end, respectively. A total of 11/16 (68.8%) ocriplasmin-treated subjects with ERG reductions achieved vitreomacular adhesion resolution, compared to those without (9/24, 37.5%). The ocriplasmin-treated subjects with ERG reductions also gained more letters on average (11.3 vs. 9.3 letters) from baseline and had a difference of 6.7 letters in mean best-corrected visual acuity by study end compared to those without ERG reductions. Conclusion: Ocriplasmin-treated subjects with ERG reductions had a higher rate of vitreomacular adhesion resolution and showed better visual improvement than their counterparts without ERG reductions or sham subjects by study end. PMID:28198785

High resolution aquifer characterization using crosshole GPR full-waveform tomography

NASA Astrophysics Data System (ADS)

Gueting, N.; Vienken, T.; Klotzsche, A.; Van Der Kruk, J.; Vanderborght, J.; Caers, J.; Vereecken, H.; Englert, A.

2016-12-01

Limited knowledge about the spatial distribution of aquifer properties typically constrains our ability to predict subsurface flow and transport. Here, we investigate the value of using high resolution full-waveform inversion of cross-borehole ground penetrating radar (GPR) data for aquifer characterization. By stitching together GPR tomograms from multiple adjacent crosshole planes, we are able to image, with a decimeter scale resolution, the dielectric permittivity and electrical conductivity of an alluvial aquifer along cross-sections of 50 m length and 10 m depth. A logistic regression model is employed to predict the spatial distribution of lithological facies on the basis of the GPR results. Vertical profiles of porosity and hydraulic conductivity from direct-push, flowmeter and grain size data suggest that the GPR predicted facies classification is meaningful with regard to porosity and hydraulic conductivity, even though the distributions of individual facies show some overlap and the absolute hydraulic conductivities from the different methods (direct-push, flowmeter, grain size) differ up to approximately one order of magnitude. Comparison of the GPR predicted facies architecture with tracer test data suggests that the plume splitting observed in a tracer experiment was caused by a hydraulically low-conductive sand layer with a thickness of only a few decimeters. Because this sand layer is identified by GPR full-waveform inversion but not by conventional GPR ray-based inversion we conclude that the improvement in spatial resolution due to full-waveform inversion is crucial to detect small-scale aquifer structures that are highly relevant for solute transport.

Transmission X-ray microscopy for full-field nano-imaging of biomaterials

PubMed Central

ANDREWS, JOY C; MEIRER, FLORIAN; LIU, YIJIN; MESTER, ZOLTAN; PIANETTA, PIERO

2010-01-01

Imaging of cellular structure and extended tissue in biological materials requires nanometer resolution and good sample penetration, which can be provided by current full-field transmission X-ray microscopic techniques in the soft and hard X-ray regions. The various capabilities of full-field transmission X-ray microscopy (TXM) include 3D tomography, Zernike phase contrast, quantification of absorption, and chemical identification via X-ray fluorescence and X-ray absorption near edge structure (XANES) imaging. These techniques are discussed and compared in light of results from imaging of biological materials including microorganisms, bone and mineralized tissue and plants, with a focus on hard X-ray TXM at ≤ 40 nm resolution. PMID:20734414

Concept of dual-resolution light field imaging using an organic photoelectric conversion film for high-resolution light field photography.

PubMed

Sugimura, Daisuke; Kobayashi, Suguru; Hamamoto, Takayuki

2017-11-01

Light field imaging is an emerging technique that is employed to realize various applications such as multi-viewpoint imaging, focal-point changing, and depth estimation. In this paper, we propose a concept of a dual-resolution light field imaging system to synthesize super-resolved multi-viewpoint images. The key novelty of this study is the use of an organic photoelectric conversion film (OPCF), which is a device that converts spectra information of incoming light within a certain wavelength range into an electrical signal (pixel value), for light field imaging. In our imaging system, we place the OPCF having the green spectral sensitivity onto the micro-lens array of the conventional light field camera. The OPCF allows us to acquire the green spectra information only at the center viewpoint with the full resolution of the image sensor. In contrast, the optical system of the light field camera in our imaging system captures the other spectra information (red and blue) at multiple viewpoints (sub-aperture images) but with low resolution. Thus, our dual-resolution light field imaging system enables us to simultaneously capture information about the target scene at a high spatial resolution as well as the direction information of the incoming light. By exploiting these advantages of our imaging system, our proposed method enables the synthesis of full-resolution multi-viewpoint images. We perform experiments using synthetic images, and the results demonstrate that our method outperforms other previous methods.

CrIS High Resolution Hyperspectral Radiances

NASA Astrophysics Data System (ADS)

Hepplewhite, C. L.; Strow, L. L.; Motteler, H.; Desouza-Machado, S. G.; Tobin, D. C.; Martin, G.; Gumley, L.

2014-12-01

The CrIS hyperspectral sounder flying on Suomi-NPPpresently has reduced spectral resolution in the mid-wave andshort-wave spectral bands due to truncation of the interferograms inorbit. CrIS has occasionally downlinked full interferograms for thesebands (0.8 cm max path, or 0.625 cm-1 point spacing) for a feworbits up to a full day. Starting Oct.1, 2014 CrIS will be commandedto download full interferograms continuously for the remainder of themission, although NOAA will not immediately produce high-spectralresolution Sensor Data Records (SDRs). Although the originalmotivation for operating in high-resolution mode was improved spectralcalibration, these new data will also improve (1) vertical sensitivityto water vapor, and (2) greatly increase the CrIS sensitivity tocarbon monoxide. This should improve (1) NWP data assimilation ofwater vapor and (2) provide long-term continuity of carbon monoxideretrievals begun with MOPITT on EOS-TERRA and AIRS on EOS-AQUA. Wehave developed a SDR algorithm to produce calibrated high-spectralresolution radiances which includes several improvements to theexisting CrIS SDR algorithm, and will present validation of thesehigh-spectral resolution radiances using a variety of techniques,including bias evaluation versus NWP model data and inter-comparisonsto AIRS and IASI using simultaneous nadir overpasses (SNOs). Theauthors are presently working to implement this algorithm for NASASuomi NPP Program production of Earth System Data Records.

Mounting and Alignment of Full-Shell Replicated X-Ray Optics

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Arnold, William; Kester, Thomas; Ramsey, Brian; Smithers, Martin

2007-01-01

We are developing grazing-incidence x-ray optics for astronomy. The optics are full-cylinder mirror shells fabricated using electroformed-nickel replication off super-polished mandrels. For space-based applications where weight is at a premium, very-thin-walled, light-weight mirrors are required. Such shells have been fabricated at MSFC with greater than 15 arcsec resolution. The challenge, however, is to preserve this resolution during mounting and assembly. We present here a status report on a mounting and alignment system currently under development at Marshall Space Flight Center to meet this challenge.

Computational efficiency and Amdahl’s law for the adaptive resolution simulation technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Junghans, Christoph; Agarwal, Animesh; Delle Site, Luigi

Here, we discuss the computational performance of the adaptive resolution technique in molecular simulation when it is compared with equivalent full coarse-grained and full atomistic simulations. We show that an estimate of its efficiency, within 10%–15% accuracy, is given by the Amdahl’s Law adapted to the specific quantities involved in the problem. The derivation of the predictive formula is general enough that it may be applied to the general case of molecular dynamics approaches where a reduction of degrees of freedom in a multi scale fashion occurs.

Computational efficiency and Amdahl’s law for the adaptive resolution simulation technique

DOE PAGES

Junghans, Christoph; Agarwal, Animesh; Delle Site, Luigi

2017-06-01

Here, we discuss the computational performance of the adaptive resolution technique in molecular simulation when it is compared with equivalent full coarse-grained and full atomistic simulations. We show that an estimate of its efficiency, within 10%–15% accuracy, is given by the Amdahl’s Law adapted to the specific quantities involved in the problem. The derivation of the predictive formula is general enough that it may be applied to the general case of molecular dynamics approaches where a reduction of degrees of freedom in a multi scale fashion occurs.

What is the spatial sampling of MISR?

Atmospheric Science Data Center

2014-12-08

... spatial resolution of the sensors without exceeding the data transfer quotas, MISR can be operated in two different data acquisition modes: ... data at the full resolution, but only for limited periods of time and therefore for limited regions, typically about 300 km in length (along ...

Imaging cells and sub-cellular structures with ultrahigh resolution full-field X-ray microscopy.

PubMed

Chien, C C; Tseng, P Y; Chen, H H; Hua, T E; Chen, S T; Chen, Y Y; Leng, W H; Wang, C H; Hwu, Y; Yin, G C; Liang, K S; Chen, F R; Chu, Y S; Yeh, H I; Yang, Y C; Yang, C S; Zhang, G L; Je, J H; Margaritondo, G

2013-01-01

Our experimental results demonstrate that full-field hard-X-ray microscopy is finally able to investigate the internal structure of cells in tissues. This result was made possible by three main factors: the use of a coherent (synchrotron) source of X-rays, the exploitation of contrast mechanisms based on the real part of the refractive index and the magnification provided by high-resolution Fresnel zone-plate objectives. We specifically obtained high-quality microradiographs of human and mouse cells with 29 nm Rayleigh spatial resolution and verified that tomographic reconstruction could be implemented with a final resolution level suitable for subcellular features. We also demonstrated that a phase retrieval method based on a wave propagation algorithm could yield good subcellular images starting from a series of defocused microradiographs. The concluding discussion compares cellular and subcellular hard-X-ray microradiology with other techniques and evaluates its potential impact on biomedical research. Copyright © 2012 Elsevier Inc. All rights reserved.

40 CFR 86.1338-84 - Emission measurement accuracy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engineering practice dictates that exhaust emission sample analyzer readings below 15 percent of full scale... computers, data loggers, etc., can provide sufficient accuracy and resolution below 15 percent of full scale... spaced points, using good engineering judgement, below 15 percent of full scale are made to ensure the...

40 CFR 86.1338-84 - Emission measurement accuracy.

Code of Federal Regulations, 2013 CFR

2013-07-01

... engineering practice dictates that exhaust emission sample analyzer readings below 15 percent of full scale... computers, data loggers, etc., can provide sufficient accuracy and resolution below 15 percent of full scale... spaced points, using good engineering judgement, below 15 percent of full scale are made to ensure the...

40 CFR 86.1338-84 - Emission measurement accuracy.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engineering practice dictates that exhaust emission sample analyzer readings below 15 percent of full scale... computers, data loggers, etc., can provide sufficient accuracy and resolution below 15 percent of full scale... spaced points, using good engineering judgement, below 15 percent of full scale are made to ensure the...

40 CFR 86.1338-84 - Emission measurement accuracy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering practice dictates that exhaust emission sample analyzer readings below 15 percent of full scale... computers, data loggers, etc., can provide sufficient accuracy and resolution below 15 percent of full scale... spaced points, using good engineering judgement, below 15 percent of full scale are made to ensure the...

Development and application of high-resolution solid- state NMR dipolar recovery techniques for spin-1/2 nuclei

NASA Astrophysics Data System (ADS)

Joers, James M.

The use of magic angle spinning to obtain high resolution solid state spectra has been well documented. This resolution occurs by coherently averaging the chemical shift anisotropy and dipolar interactions to zero over the period of a full rotation. While this allows for higher resolution, the structural information is seemingly lost to the spectrometer eye. Thus, high resolution spectra and structural information appear to be mutually exlusive. Recently, the push in solid state NMR is the development of recoupling techniques which afford both high resolution and structural information. The following dissertation demonstrates the feasibility of implementing such experiments in solving real world problems, and is centered on devising a method to recover homonuclear dipolar interactions in the high resolution regime.

Off-axis full-field swept-source optical coherence tomography using holographic refocusing

NASA Astrophysics Data System (ADS)

Hillmann, Dierck; Franke, Gesa; Hinkel, Laura; Bonin, Tim; Koch, Peter; Hüttmann, Gereon

2013-03-01

We demonstrate a full-field swept-source OCT using an off-axis geometry of the reference illumination. By using holographic refocusing techniques, a uniform lateral resolution is achieved over the measurement depth of approximately 80 Rayleigh lengths. Compared to a standard on-axis setup, artifacts and autocorrelation signals are suppressed and the measurement depth is doubled by resolving the complex conjugate ambiguity. Holographic refocusing was done efficiently by Fourier-domain resampling as demonstrated before in inverse scattering and holoscopy. It allowed to reconstruct a complete volume with about 10μm resolution over the complete measurement depth of more than 10mm. Off-axis full-field swept-source OCT enables high measurement depths, spanning many Rayleigh lengths with reduced artifacts.

Transmission X-ray microscopy for full-field nano imaging of biomaterials.

PubMed

Andrews, Joy C; Meirer, Florian; Liu, Yijin; Mester, Zoltan; Pianetta, Piero

2011-07-01

Imaging of cellular structure and extended tissue in biological materials requires nanometer resolution and good sample penetration, which can be provided by current full-field transmission X-ray microscopic techniques in the soft and hard X-ray regions. The various capabilities of full-field transmission X-ray microscopy (TXM) include 3D tomography, Zernike phase contrast, quantification of absorption, and chemical identification via X-ray fluorescence and X-ray absorption near edge structure imaging. These techniques are discussed and compared in light of results from the imaging of biological materials including microorganisms, bone and mineralized tissue, and plants, with a focus on hard X-ray TXM at ≤ 40-nm resolution. Copyright © 2010 Wiley-Liss, Inc.

Full-Frame Reference for Test Photo of Moon

NASA Technical Reports Server (NTRS)

2005-01-01

This pair of views shows how little of the full image frame was taken up by the Moon in test images taken Sept. 8, 2005, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The Mars-bound camera imaged Earth's Moon from a distance of about 10 million kilometers (6 million miles) away -- 26 times the distance between Earth and the Moon -- as part of an activity to test and calibrate the camera. The images are very significant because they show that the Mars Reconnaissance Orbiter spacecraft and this camera can properly operate together to collect very high-resolution images of Mars. The target must move through the camera's telescope view in just the right direction and speed to acquire a proper image. The day's test images also demonstrate that the focus mechanism works properly with the telescope to produce sharp images.

Out of the 20,000-pixel-by-6,000-pixel full frame, the Moon's diameter is about 340 pixels, if the full Moon could be seen. The illuminated crescent is about 60 pixels wide, and the resolution is about 10 kilometers (6 miles) per pixel. At Mars, the entire image region will be filled with high-resolution information.

The Mars Reconnaissance Orbiter, launched on Aug. 12, 2005, is on course to reach Mars on March 10, 2006. After gradually adjusting the shape of its orbit for half a year, it will begin its primary science phase in November 2006. From the mission's planned science orbit about 300 kilometers (186 miles) above the surface of Mars, the high resolution camera will be able to discern features as small as one meter or yard across.

The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate. Lockheed Martin Space Systems, Denver, prime contractor for the project, built the spacecraft. Ball Aerospace & Technologies Corp., Boulder, Colo., built the High Resolution Imaging Science Experiment instrument for the University of Arizona, Tucson, to provide to the mission. The HiRISE Operations Center at the University of Arizona processes images from the camera.

Ultrahigh resolution photographic films for X-ray/EUV/FUV astronomy

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Walker, Arthur B. C., Jr.; Deforest, Craig E.; Watts, Richard; Tarrio, Charles

1993-01-01

The quest for ultrahigh resolution full-disk images of the sun at soft X-ray/EUV/FUV wavelengths has increased the demand for photographic films with broad spectral sensitivity, high spatial resolution, and wide dynamic range. These requirements were made more stringent by the recent development of multilayer telescopes and coronagraphs capable of operating at normal incidence at soft X-ray/EUV wavelengths. Photographic films are the only detectors now available with the information storage capacity and dynamic range such as is required for recording images of the solar disk and corona simultaneously with sub arc second spatial resolution. During the Stanford/MSFC/LLNL Rocket X-Ray Spectroheliograph and Multi-Spectral Solar Telescope Array (MSSTA) programs, we utilized photographic films to obtain high resolution full-disk images of the sun at selected soft X-ray/EUV/FUV wavelengths. In order to calibrate our instrumentation for quantitative analysis of our solar data and to select the best emulsions and processing conditions for the MSSTA reflight, we recently tested several photographic films. These studies were carried out at the NIST SURF II synchrotron and the Stanford Synchrotron Radiation Laboratory. In this paper, we provide the results of those investigations.

Pixel-super-resolved lensfree holography using adaptive relaxation factor and positional error correction

NASA Astrophysics Data System (ADS)

Zhang, Jialin; Chen, Qian; Sun, Jiasong; Li, Jiaji; Zuo, Chao

2018-01-01

Lensfree holography provides a new way to effectively bypass the intrinsical trade-off between the spatial resolution and field-of-view (FOV) of conventional lens-based microscopes. Unfortunately, due to the limited sensor pixel-size, unpredictable disturbance during image acquisition, and sub-optimum solution to the phase retrieval problem, typical lensfree microscopes only produce compromised imaging quality in terms of lateral resolution and signal-to-noise ratio (SNR). In this paper, we propose an adaptive pixel-super-resolved lensfree imaging (APLI) method to address the pixel aliasing problem by Z-scanning only, without resorting to subpixel shifting or beam-angle manipulation. Furthermore, an automatic positional error correction algorithm and adaptive relaxation strategy are introduced to enhance the robustness and SNR of reconstruction significantly. Based on APLI, we perform full-FOV reconstruction of a USAF resolution target across a wide imaging area of {29.85 mm2 and achieve half-pitch lateral resolution of 770 nm, surpassing 2.17 times of the theoretical Nyquist-Shannon sampling resolution limit imposed by the sensor pixel-size (1.67 μm). Full-FOV imaging result of a typical dicot root is also provided to demonstrate its promising potential applications in biologic imaging.

High resolution aquifer characterization using crosshole GPR full-waveform tomography: Comparison with direct-push and tracer test data

NASA Astrophysics Data System (ADS)

Gueting, Nils; Vienken, Thomas; Klotzsche, Anja; van der Kruk, Jan; Vanderborght, Jan; Caers, Jef; Vereecken, Harry; Englert, Andreas

2017-01-01

Limited knowledge about the spatial distribution of aquifer properties typically constrains our ability to predict subsurface flow and transport. Here we investigate the value of using high resolution full-waveform inversion of cross-borehole ground penetrating radar (GPR) data for aquifer characterization. By stitching together GPR tomograms from multiple adjacent crosshole planes, we are able to image, with a decimeter scale resolution, the dielectric permittivity and electrical conductivity of an alluvial aquifer along cross sections of 50 m length and 10 m depth. A logistic regression model is employed to predict the spatial distribution of lithological facies on the basis of the GPR results. Vertical profiles of porosity and hydraulic conductivity from direct-push, flowmeter and grain size data suggest that the GPR predicted facies classification is meaningful with regard to porosity and hydraulic conductivity, even though the distributions of individual facies show some overlap and the absolute hydraulic conductivities from the different methods (direct-push, flowmeter, grain size) differ up to approximately one order of magnitude. Comparison of the GPR predicted facies architecture with tracer test data suggests that the plume splitting observed in a tracer experiment was caused by a hydraulically low-conductive sand layer with a thickness of only a few decimeters. Because this sand layer is identified by GPR full-waveform inversion but not by conventional GPR ray-based inversion we conclude that the improvement in spatial resolution due to full-waveform inversion is crucial to detect small-scale aquifer structures that are highly relevant for solute transport.

Data rescue of NASA First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE) aerial observations

NASA Astrophysics Data System (ADS)

Santhana Vannan, S. K.; Boyer, A.; Deb, D.; Beaty, T.; Wei, Y.; Wei, Z.

2017-12-01

The Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) for biogeochemical dynamics is one of the NASA Earth Observing System Data and Information System (EOSDIS) data centers. ORNL DAAC (https://daac.ornl.gov) is responsible for data archival, product development and distribution, and user support for biogeochemical and ecological data and models. In particular, ORNL DAAC has been providing data management support for NASA's terrestrial ecology field campaign programs for the last several decades. Field campaigns combine ground, aircraft, and satellite-based measurements in specific ecosystems over multi-year time periods. The data collected during NASA field campaigns are archived at the ORNL DAAC (https://daac.ornl.gov/get_data/). This paper describes the effort of the ORNL DAAC team for data rescue of a First ISLSCP Field Experiment (FIFE) dataset containing airborne and satellite data observations from the 1980s. The data collected during the FIFE campaign contain high resolution aerial imageries collected over Kansas. The data rescue workflow was prepared to test for successful recovery of the data from a CD-ROM and to ensure that the data are usable and preserved for the future. The imageries contain spectral reflectance data that can be used as a historical benchmark to examine climatological and ecological changes in the Kansas region since the 1980s. Below are the key steps taken to convert the files to modern standards. Decompress the imageries using custom compression software provided with the data. The compression algorithm created for MS-DOS in 1980s had to be set up to run on modern computer systems. Decompressed files were geo-referenced by using metadata information stored in separate compressed header files. Standardized file names were applied (File names and details were described in separate readme documents). Image files were converted to GeoTIFF format with embedded georeferencing information. Leverage Open Geospatial Consortium (OGC) Web services to provide dynamic data transformation and visualization. We will describe the steps in detail and share lessons learned during the AGU session.

Statistical analysis of low-voltage EDS spectrum images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, I.M.

1998-03-01

The benefits of using low ({le}5 kV) operating voltages for energy-dispersive X-ray spectrometry (EDS) of bulk specimens have been explored only during the last few years. This paper couples low-voltage EDS with two other emerging areas of characterization: spectrum imaging of a computer chip manufactured by a major semiconductor company. Data acquisition was performed with a Philips XL30-FEG SEM operated at 4 kV and equipped with an Oxford super-ATW detector and XP3 pulse processor. The specimen was normal to the electron beam and the take-off angle for acquisition was 35{degree}. The microscope was operated with a 150 {micro}m diameter finalmore » aperture at spot size 3, which yielded an X-ray count rate of {approximately}2,000 s{sup {minus}1}. EDS spectrum images were acquired as Adobe Photoshop files with the 4pi plug-in module. (The spectrum images could also be stored as NIH Image files, but the raw data are automatically rescaled as maximum-contrast (0--255) 8-bit TIFF images -- even at 16-bit resolution -- which poses an inconvenience for quantitative analysis.) The 4pi plug-in module is designed for EDS X-ray mapping and allows simultaneous acquisition of maps from 48 elements plus an SEM image. The spectrum image was acquired by re-defining the energy intervals of 48 elements to form a series of contiguous 20 eV windows from 1.25 kV to 2.19 kV. A spectrum image of 450 x 344 pixels was acquired from the specimen with a sampling density of 50 nm/pixel and a dwell time of 0.25 live seconds per pixel, for a total acquisition time of {approximately}14 h. The binary data files were imported into Mathematica for analysis with software developed by the author at Oak Ridge National Laboratory. A 400 x 300 pixel section of the original image was analyzed. MSA required {approximately}185 Mbytes of memory and {approximately}18 h of CPU time on a 300 MHz Power Macintosh 9600.« less

Prejudice, Ethnocentrism, and Violence in an Age of High Technology.

ERIC Educational Resources Information Center

Hamburg, David A.

This essay provides an historical perspective on conflict and discusses the relationship of prejudice and ethnocentrism to intergroup conflict, prejudice and conflict resolution in childhood, as well as approaches to conflict resolution in society. History is full of hateful and destructive indulgences based on religious, racial, and other…

High-resolution spectrometrometry/interferometer

NASA Technical Reports Server (NTRS)

Breckinridge, J. B.; Norton, R. H.; Schindler, R. A.

1980-01-01

Modified double-pass interferometer has several features that maximize its resolution. Proposed for rocket-borne probes of upper atmosphere, it includes cat's-eye retroreflectors in both arms, wedge-shaped beam splitter, and wedged optical-path compensator. Advantages are full tilt compensation, minimal spectrum "channeling," easy tunability, maximum fringe contrast, and even two-sided interferograms.

Ultra-high resolution electron microscopy

DOE PAGES

Oxley, Mark P.; Lupini, Andrew R.; Pennycook, Stephen J.

2016-12-23

The last two decades have seen dramatic advances in the resolution of the electron microscope brought about by the successful correction of lens aberrations that previously limited resolution for most of its history. Here we briefly review these advances, the achievement of sub-Ångstrom resolution and the ability to identify individual atoms, their bonding configurations and even their dynamics and diffusion pathways. We then present a review of the basic physics of electron scattering, lens aberrations and their correction, and an approximate imaging theory for thin crystals which provides physical insight into the various different imaging modes. Then we proceed tomore » describe a more exact imaging theory starting from Yoshioka’s formulation and covering full image simulation methods using Bloch waves, the multislice formulation and the frozen phonon/quantum excitation of phonons models. Delocalization of inelastic scattering has become an important limiting factor at atomic resolution. We therefore discuss this issue extensively, showing how the full-width-half-maximum is the appropriate measure for predicting image contrast, but the diameter containing 50% of the excitation is an important measure of the range of the interaction. These two measures can differ by a factor of 5, are not a simple function of binding energy, and full image simulations are required to match to experiment. The Z-dependence of annular dark field images is also discussed extensively, both for single atoms and for crystals, and we show that temporal incoherence must be included accurately if atomic species are to be identified through matching experimental intensities to simulations. Finally we mention a few promising directions for future investigation.« less

High-resolution imaging of biological tissue with full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhu, Yue; Gao, Wanrong

2015-03-01

A new full-field optical coherence tomography system with high-resolution has been developed for imaging of cells and tissues. Compared with other FF-OCT (Full-field optical coherence tomography, FF-OCT) systems illuminated with optical fiber bundle, the improved Köhler illumination arrangement with a halogen lamp was used in the proposed FF-OCT system. High numerical aperture microscopic objectives were used for imaging and a piezoelectric ceramic transducer (PZT) was used for phase-shifting. En-face tomographic images can be obtained by applying the five-step phase-shifting algorithm to a series of interferometric images which are recorded by a smart camera. Three-dimensional images can be generated from these tomographic images. Imaging of the chip of Intel Pentium 4 processor demonstrated the ultrahigh resolution of the system (lateral resolution is 0.8μm ), which approaches the theoretical resolution 0.7 μm× 0.5 μm (lateral × axial). En-face images of cells of onion show an excellent performance of the system in generating en-face images of biological tissues. Then, unstained pig stomach was imaged as a tissue and gastric pits could be easily recognized using FF-OCT system. Our study provides evidence for the potential ability of FFOCT in identifying gastric pits from pig stomach tissue. Finally, label-free and unstained ex vivo human liver tissues from both normal and tumor were imaged with this FFOCT system. The results show that the setup has the potential for medical diagnosis applications such liver cancer diagnosis.

[Comparison of dignity determination of mammographic microcalcification with two systems for digital full-field mammography with different detector resolution: a retrospective clinical study].

PubMed

Schulz-Wendtland, R; Hermann, K-P; Adamietz, B; Meier-Meitinger, M; Wenkel, E; Lell, M; Anders, K; Uder, M

2011-02-01

The aim of this retrospective clinical study was to compare the diagnostic accuracy of the novel 50 µm FFDM (full-field digital mammography) system (DR) with an established 70 µm system (DR) in the differential diagnosis between benign and malignant clusters of microcalcification (n=50) (BI-RADS™ classification 4/5) and to assess the possible incremental value of the 50 µm pixel-pitch on specificity. From March 2009 to September 2009, 50 patients underwent full-field digital mammography (FFDM) (detector resolution 70 µm) (Novation, Siemens, Erlangen, Germany). As there were suspicious signs of microcalcification classified with BI-RADS™ 4/5 after diagnosis and preoperative wire localization, control images were made with the new FFDM system (detector: resolution 50 µm) (Amulet, Fujifilm, Tokyo, Japan) with the same exposure parameters. The diagnosis was determined after the operation by five radiologists with different experience in digital mammography from randomly distributed mediolateral views (monitor reading) whose results were correlated with the final histology of all lesions. Histopathology revealed 19 benign and 31 malignant lesions in 50 patients after open biopsy. The results of the five readers showed a higher sensitivity of the new FFDM system (80.0%) in the ability to recognize malignant microcalcification in comparison to the established system (74.8%). The specificity (75.8 versus 71.6%) was slightly higher for the new system but these results were not statistically significant (p<0.001). Considering the diagnostic accuracy, the new system (detector: resolution 50 µm) was also slightly superior to the well-known system (detector: resolution 70 µm) (80.1% versus 76.4%). Our study has shown that the new full-field digital mammography system using the novel detector compared with the already established FFDM system with respect to the assessment of microcalcification is at least equivalent.

HPLC-high-resolution mass spectrometry with polarity switching for increasing throughput of human in vitro cocktail drug-drug interaction assay.

PubMed

Ramanathan, Ragu; Ghosal, Anima; Ramanathan, Lakshmi; Comstock, Kate; Shen, Helen; Ramanathan, Dil

2018-05-01

Evaluation of HPLC-high-resolution mass spectrometry (HPLC-HRMS) full scan with polarity switching for increasing throughput of human in vitro cocktail drug-drug interaction assay. Microsomal incubates were analyzed using a high resolution and high mass accuracy Q-Exactive mass spectrometer to collect integrated qualitative and quantitative (qual/quant) data. Within assay, positive-to-negative polarity switching HPLC-HRMS method allowed quantification of eight and two probe compounds in the positive and negative ionization modes, respectively, while monitoring for LOR and its metabolites. LOR-inhibited CYP2C19 and showed higher activity for CYP2D6, CYP2E1 and CYP3A4. Overall, LC-HRMS-based nontargeted full scan quantitation allowed to improve the throughput of the in vitro cocktail drug-drug interaction assay.

Quantification of dislocation nucleation stress in TiN through high-resolution in situ indentation experiments and first principles calculations

DOE PAGES

Li, N.; Yadav, S. K.; Liu, X. -Y.; ...

2015-11-05

Using the in situ indentation of TiN in a high-resolution transmission electron microscope, the nucleation of full as well as partial dislocations has been observed from {001} and {111} surfaces, respectively. The critical elastic strains associated with the nucleation of the dislocations were analyzed from the recorded atomic displacements, and the nucleation stresses corresponding to the measured critical strains were computed using density functional theory. The resolved shear stress was estimated to be 13.8 GPa for the partial dislocation 1/6 <110> {111} and 6.7 GPa for the full dislocation ½ <110> {110}. Moreover, such an approach of quantifying nucleation stressesmore » for defects via in situ high-resolution experiment coupled with density functional theory calculation may be applied to other unit processes.« less

Graded zooming

DOEpatents

Coffland, Douglas R.

2006-04-25

A system for increasing the resolution in the far field resolution of video or still frame images, while maintaining full coverage in the near field. The system includes a camera connected to a computer. The computer applies a specific zooming scale factor to each of line of pixels and continuously increases the scale factor of the line of pixels from the bottom to the top to capture the scene in the near field, yet maintain resolution in the scene in the far field.

Adaptive pixel-super-resolved lensfree in-line digital holography for wide-field on-chip microscopy.

PubMed

Zhang, Jialin; Sun, Jiasong; Chen, Qian; Li, Jiaji; Zuo, Chao

2017-09-18

High-resolution wide field-of-view (FOV) microscopic imaging plays an essential role in various fields of biomedicine, engineering, and physical sciences. As an alternative to conventional lens-based scanning techniques, lensfree holography provides a new way to effectively bypass the intrinsical trade-off between the spatial resolution and FOV of conventional microscopes. Unfortunately, due to the limited sensor pixel-size, unpredictable disturbance during image acquisition, and sub-optimum solution to the phase retrieval problem, typical lensfree microscopes only produce compromised imaging quality in terms of lateral resolution and signal-to-noise ratio (SNR). Here, we propose an adaptive pixel-super-resolved lensfree imaging (APLI) method which can solve, or at least partially alleviate these limitations. Our approach addresses the pixel aliasing problem by Z-scanning only, without resorting to subpixel shifting or beam-angle manipulation. Automatic positional error correction algorithm and adaptive relaxation strategy are introduced to enhance the robustness and SNR of reconstruction significantly. Based on APLI, we perform full-FOV reconstruction of a USAF resolution target (~29.85 mm 2 ) and achieve half-pitch lateral resolution of 770 nm, surpassing 2.17 times of the theoretical Nyquist-Shannon sampling resolution limit imposed by the sensor pixel-size (1.67µm). Full-FOV imaging result of a typical dicot root is also provided to demonstrate its promising potential applications in biologic imaging.

Development of a Direct Fabrication Technique for Full-Shell X-Ray Optics

NASA Technical Reports Server (NTRS)

Gubarev, M.; Kolodziejczak, J. K.; Griffith, C.; Roche, J.; Smith, W. S.; Kester, T.; Atkins, C.; Arnold, W.; Ramsey, B.

2016-01-01

Future astrophysical missions will require fabrication technology capable of producing high angular resolution x-ray optics. A full-shell direct fabrication approach using modern robotic polishing machines has the potential for producing high resolution, light-weight and affordable x-ray mirrors that can be nested to produce large collecting area. This approach to mirror fabrication, based on the use of the metal substrates coated with nickel phosphorous alloy, is being pursued at MSFC. The design of the polishing fixtures for the direct fabrication, the surface figure metrology techniques used and the results of the polishing experiments are presented.

Linear-array based full-view high-resolution photoacoustic computed tomography of whole mouse brain functions in vivo

NASA Astrophysics Data System (ADS)

Li, Lei; Zhang, Pengfei; Wang, Lihong V.

2018-02-01

Photoacoustic computed tomography (PACT) is a non-invasive imaging technique offering high contrast, high resolution, and deep penetration in biological tissues. We report a photoacoustic computed tomography (PACT) system equipped with a high frequency linear array for anatomical and functional imaging of the mouse whole brain. The linear array was rotationally scanned in the coronal plane to achieve the full-view coverage. We investigated spontaneous neural activities in the deep brain by monitoring the hemodynamics and observed strong interhemispherical correlations between contralateral regions, both in the cortical layer and in the deep regions.

Real-time stereo generation for surgical vision during minimal invasive robotic surgery

NASA Astrophysics Data System (ADS)

Laddi, Amit; Bhardwaj, Vijay; Mahapatra, Prasant; Pankaj, Dinesh; Kumar, Amod

2016-03-01

This paper proposes a framework for 3D surgical vision for minimal invasive robotic surgery. It presents an approach for generating the three dimensional view of the in-vivo live surgical procedures from two images captured by very small sized, full resolution camera sensor rig. A pre-processing scheme is employed to enhance the image quality and equalizing the color profile of two images. Polarized Projection using interlacing two images give a smooth and strain free three dimensional view. The algorithm runs in real time with good speed at full HD resolution.

Distinct Retinal Capillary Plexuses in Normal Eyes as Observed in Optical Coherence Tomography Angiography Axial Profile Analysis.

PubMed

Hirano, Takao; Chanwimol, Karntida; Weichsel, Julian; Tepelus, Tudor; Sadda, Srinivas

2018-06-20

Optical coherence tomography angiography (OCTA) allows the retinal microvasculature to be visualized at various retinal depths. Previous studies introduced OCTA axial profile analysis and showed regional variations in the number and location of axially distinct vascular retinal plexuses. OCTA acquisition and processing approaches, however, vary in terms of their resulting transverse and axial resolutions, and especially the latter could potentially influence the profile analysis results. Our study imaged normal eyes using the Spectralis OCT2 with a full-spectrum, probabilistic OCTA algorithm, that, in marked contrast to split-spectrum approaches, preserves the original high OCT axial resolution also within the resulting OCTA signal. En face OCTA images are generally created by averaging flow signals over a finite axial depth window. However, we assessed regional OCTA signal profiles at each depth position at full axial resolution. All regions had two sharp vessel density peaks near the inner and outer boundaries of the inner nuclear layer, indicating separate intermediate and deep capillary plexuses. The superficial vascular plexus (SVP) separated into two distinct peaks within the ganglion cell layer in the parafoveal zone. The nasal, superior, and inferior perifovea had a deeper SVP peak that was shifted anteriorly compared to the parafoveal zone. Axial vascular density analysis with high-resolution, full spectrum OCTA thus allows healthy retinal vasculature to be precisely reconstructed and may be useful for clinically assessing retinal pathology.

A Synthetic Study on the Resolution of 2D Elastic Full Waveform Inversion

NASA Astrophysics Data System (ADS)

Cui, C.; Wang, Y.

2017-12-01

Gradient based full waveform inversion is an effective method in seismic study, it makes full use of the information given by seismic records and is capable of providing a more accurate model of the interior of the earth at a relatively low computational cost. However, the strong non-linearity of the problem brings about many difficulties in the assessment of its resolution. Synthetic inversions are therefore helpful before an inversion based on real data is made. Checker-board test is a commonly used method, but it is not always reliable due to the significant difference between a checker-board and the true model. Our study aims to provide a basic understanding of the resolution of 2D elastic inversion by examining three main factors that affect the inversion result respectively: 1. The structural characteristic of the model; 2. The level of similarity between the initial model and the true model; 3. The spacial distribution of sources and receivers. We performed about 150 synthetic inversions to demonstrate how each factor contributes to quality of the result, and compared the inversion results with those achieved by checker-board tests. The study can be a useful reference to assess the resolution of an inversion in addition to regular checker-board tests, or to determine whether the seismic data of a specific region is sufficient for a successful inversion.

Planetary Education and Outreach Using the NOAA Science on a Sphere

NASA Technical Reports Server (NTRS)

Simon-Miller, A. A.; Williams, D. R.; Smith, S. M.; Friedlander, J. S.; Mayo, L. A.; Clark, P. E.; Henderson, M. A.

2011-01-01

Science On a Sphere (SOS) is a large visualization system, developed by the National Oceanic and Atmospheric Administration (NOAH), that uses computers running Redhat Linux and four video projectors to display animated data onto the outside of a sphere. Said another way, SOS is a stationary globe that can show dynamic, animated images in spherical form. Visualization of cylindrical data maps show planets, their atmosphere, oceans, and land, in very realistic form. The SOS system uses 4 video projectors to display images onto the sphere. Each projector is driven by a separate computer, and a fifth computer is used to control the operation of the display computers. Each computer is a relatively powerful PC with a high-end graphics card. The video projectors have native XGA resolution. The projectors are placed at the corners of a 30' x 30' square with a 68" carbon fiber sphere suspended in the center of the square. The equator of the sphere is typically located 86" off the floor. SOS uses common image formats such as JPEG, or TIFF in a very specific, but simple form; the images are plotted on an equatorial cylindrical equidistant projection, or as it is commonly known, a latitude/longitude grid, where the image is twice as wide as it is high (rectangular). 2048x] 024 is the minimum usable spatial resolution without some noticeable pixelation. Labels and text can be applied within the image, or using a timestamp-like feature within the SOS system software. There are two basic modes of operation for SOS: displaying a single image or an animated sequence of frames. The frame or frames can be setup to rotate or tilt, as in a planetary rotation. Sequences of images that animate through time produce a movie visualization, with or without an overlain soundtrack. After the images are processed, SOS will display the images in sequence and play them like a movie across the entire sphere surface. Movies can be of any arbitrary length, limited mainly by disk space and can be animated at frame rates up to 30 frames per second. Transitions, special effects, and other computer graphics techniques can be added to a sequence through the use of off-the-shelf software, like Final Cut Pro. However, one drawback is that the Sphere cannot be used in the same manner as a flat movie screen; images cannot be pushed to a "side", a highlighted area must be viewable to all sides of the room simultaneously, and some transitions do not work as well as others. We discuss these issues and workarounds in our poster.

Megahertz-resolution programmable microwave shaper.

PubMed

Li, Jilong; Dai, Yitang; Yin, Feifei; Li, Wei; Li, Ming; Chen, Hongwei; Xu, Kun

2018-04-15

A novel microwave shaper is proposed and demonstrated, of which the microwave spectral transfer function could be fully programmable with high resolution. We achieve this by bandwidth-compressed mapping a programmable optical wave-shaper, which has a lower frequency resolution of tens of gigahertz, to a microwave one with resolution of tens of megahertz. This is based on a novel technology of "bandwidth scaling," which employs bandwidth-stretched electronic-to-optical conversion and bandwidth-compressed optical-to-electronic conversion. We demonstrate the high resolution and full reconfigurability experimentally. Furthermore, we show the group delay variation could be greatly enlarged after mapping; this is then verified by the experiment with an enlargement of 194 times. The resolution improvement and group delay magnification significantly distinguish our proposal from previous optics-to-microwave spectrum mapping.

Rapid mapping of hurricane damage to forests

Treesearch

Erik M. Nielsen

2009-01-01

The prospects for producing rapid, accurate delineations of the spatial extent of forest wind damage were evaluated using Hurricane Katrina as a test case. A damage map covering the full spatial extent of Katrina?s impact was produced from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery using higher resolution training data. Forest damage...

3D laser imaging for ODOT interstate network at true 1-mm resolution.

DOT National Transportation Integrated Search

2014-12-01

With the development of 3D laser imaging technology, the latest iteration of : PaveVision3D Ultra can obtain true 1mm resolution 3D data at full-lane coverage in all : three directions at highway speed up to 60MPH. This project provides rapid survey ...

A resolution supporting full implementation of the Comprehensive Peace Agreement and other efforts to promote peace and stability in Sudan, and for other purposes.

THOMAS, 111th Congress

Sen. Feingold, Russell D. [D-WI

2010-02-01

Senate - 03/04/2010 Resolution agreed to in Senate without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

Strategy for the elucidation of elemental compositions of trace analytes based on a mass resolution of 100,000 full width at half maximum.

PubMed

Kaufmann, Anton

2010-07-30

Elemental compositions (ECs) can be elucidated by evaluating the high-resolution mass spectra of unknown or suspected unfragmented analyte ions. Classical approaches utilize the exact mass of the monoisotopic peak (M + 0) and the relative abundance of isotope peaks (M + 1 and M + 2). The availability of high-resolution instruments like the Orbitrap currently permits mass resolutions up to 100,000 full width at half maximum. This not only allows the determination of relative isotopic abundances (RIAs), but also the extraction of other diagnostic information from the spectra, such as fully resolved signals originating from (34)S isotopes and fully or partially resolved signals related to (15)N isotopes (isotopic fine structure). Fully and partially resolved peaks can be evaluated by visual inspection of the measured peak profiles. This approach is shown to be capable of correctly discarding many of the EC candidates which were proposed by commercial EC calculating algorithms. Using this intuitive strategy significantly extends the upper mass range for the successful elucidation of ECs. Copyright 2010 John Wiley & Sons, Ltd.

Usefulness of high resolution coastal models for operational oil spill forecast: the "Full City" accident

NASA Astrophysics Data System (ADS)

Broström, G.; Carrasco, A.; Hole, L. R.; Dick, S.; Janssen, F.; Mattsson, J.; Berger, S.

2011-11-01

Oil spill modeling is considered to be an important part of a decision support system (DeSS) for oil spill combatment and is useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas, implying that low resolution basin scale ocean models are of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the "Full City" accident on the Norwegian south coast and compare operational simulations from three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws, but by applying ocean forcing data of higher resolution (1.5 km resolution), the model system shows results that compare well with observations. The study also shows that an ensemble of results from the three different models is useful when predicting/analyzing oil spill in coastal areas.

Usefulness of high resolution coastal models for operational oil spill forecast: the Full City accident

NASA Astrophysics Data System (ADS)

Broström, G.; Carrasco, A.; Hole, L. R.; Dick, S.; Janssen, F.; Mattsson, J.; Berger, S.

2011-06-01

Oil spill modeling is considered to be an important decision support system (DeSS) useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas implying that low resolution basin scale ocean models is of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the Full City accident on the Norwegian south coast and compare three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws but including an analysis based on a higher resolution model (1.5 km resolution) for the area the model system show results that compare well with observations. The study also shows that an ensemble using three different models is useful when predicting/analyzing oil spill in coastal areas.

A full range detector for the HIRRBS high resolution RBS magnetic spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skala, Wayne G.; Haberl, Arthur W.; Bakhru, Hassaram

2013-04-19

The UAlbany HIRRBS (High Resolution RBS) system has been updated for better use in rapid analysis. The focal plane detector now covers the full range from U down to O using a linear stepper motor to translate the 1-cm detector across the 30-cm range. Input is implemented with zero-back-angle operation in all cases. The chamber has been modified to allow for quick swapping of sample holders, including a channeling goniometer. A fixed standard surface-barrier detector allows for normal RBS simultaneously with use of the magnetic spectrometer. The user can select a region on the standard spectrum or can select anmore » element edge or an energy point for collection of the expanded spectrum portion. The best resolution currently obtained is about 2-to-3 keV, probably representing the energy width of the incoming beam. Calibration is maintained automatically for any spectrum portion and any beam energy from 1.0 to 3.5 MeV. Element resolving power, sensitivity and depth resolution are shown using several examples. Examples also show the value of simultaneous conventional RBS.« less

Full-Frame Reference for Test Photo of Moon

NASA Image and Video Library

2005-09-10

This pair of views shows how little of the full image frame was taken up by the Moon in test images taken Sept. 8, 2005, by the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

Efficient fabrication method of nano-grating for 3D holographic display with full parallax views.

PubMed

Wan, Wenqiang; Qiao, Wen; Huang, Wenbin; Zhu, Ming; Fang, Zongbao; Pu, Donglin; Ye, Yan; Liu, Yanhua; Chen, Linsen

2016-03-21

Without any special glasses, multiview 3D displays based on the diffractive optics can present high resolution, full-parallax 3D images in an ultra-wide viewing angle. The enabling optical component, namely the phase plate, can produce arbitrarily distributed view zones by carefully designing the orientation and the period of each nano-grating pixel. However, such 3D display screen is restricted to a limited size due to the time-consuming fabricating process of nano-gratings on the phase plate. In this paper, we proposed and developed a lithography system that can fabricate the phase plate efficiently. Here we made two phase plates with full nano-grating pixel coverage at a speed of 20 mm²/mins, a 500 fold increment in the efficiency when compared to the method of E-beam lithography. One 2.5-inch phase plate generated 9-view 3D images with horizontal-parallax, while the other 6-inch phase plate produced 64-view 3D images with full-parallax. The angular divergence in horizontal axis and vertical axis was 1.5 degrees, and 1.25 degrees, respectively, slightly larger than the simulated value of 1.2 degrees by Finite Difference Time Domain (FDTD). The intensity variation was less than 10% for each viewpoint, in consistency with the simulation results. On top of each phase plate, a high-resolution binary masking pattern containing amplitude information of all viewing zone was well aligned. We achieved a resolution of 400 pixels/inch and a viewing angle of 40 degrees for 9-view 3D images with horizontal parallax. In another prototype, the resolution of each view was 160 pixels/inch and the view angle was 50 degrees for 64-view 3D images with full parallax. As demonstrated in the experiments, the homemade lithography system provided the key fabricating technology for multiview 3D holographic display.

Natural history of frozen shoulder: fact or fiction? A systematic review.

PubMed

Wong, C K; Levine, W N; Deo, K; Kesting, R S; Mercer, E A; Schram, G A; Strang, B L

2017-03-01

In 1940s, it was proposed that frozen shoulder progresses through a self-limiting natural history of painful, stiff and recovery phases, leading to full recovery without treatment. However, clinical evidence of persistent limitations lasting for years contradicts this assumption. To assess evidence for the natural history theory of frozen shoulder by examining: (1) progression through recovery phases, and (2) full resolution without treatment. MEDLINE, PubMed, EBSCO CINAHL and PEDro database searches augmented by hand searching. Cohort or randomised controlled trials with no-treatment comparison groups including adults with frozen shoulder who received no treatment and reporting range of motion, pain or function for ≥6 months. Reviewers assessed study eligibility and quality, and extracted data before reaching consensus. Limited early range-of-motion improvements and greater late improvements defined progression through recovery phases. Restoration of normal range of motion and previous function defined full resolution. Of 508 citations, 13 articles were reviewed and seven were included in this review. Low-quality evidence suggested that no treatment yielded some, but not complete, improvement in range of motion after 1 to 4 years of follow-up. No evidence supported the theory of progression through recovery phases to full resolution without treatment. On the contrary, moderate-quality evidence from three randomised controlled trials with longitudinal data demonstrated that most improvement occurred early, not late. Low-quality evidence revealed the weakness of longstanding assumptions about frozen shoulder. Contradictory evidence and a lack of supporting evidence shows that the theory of recovery phases leading to complete resolution without treatment for frozen shoulder is unfounded. Copyright © 2016 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Endoscopic Full-Field Swept-Source Optical Coherence Tomography Neuroimaging System

NASA Astrophysics Data System (ADS)

Felts Almog, Ilan

Optical Coherence Tomography (OCT) has the capability to differentiate brain elements with intrinsic contrast and at a resolution an order-of-magnitude higher than other imaging modalities. This thesis investigates the feasibility of OCT for neuroimaging applied to neurosurgical guidance. We present, to our knowledge, the first Full-Field Swept-Source OCT system operating near a wavelength of 1310 nm, achieving a transverse imaging resolution of 6.5 mum, an axial resolution of 14 mum in tissue and a field of view of 270 mum x 180 mum x 400 mum. Imaging experiments were performed on rat brain tissues ex vivo, human cortical tissue ex vivo, and rats in vivo. A multi-level threshold metric applied on the intensity of the images led to a plausible correlation between the observed density and location in the brain. The proof-of-concept OCT system can be improved and miniaturized for clinical use.

Atmospheric and Fundamental Parameters of Stars in Hubble's Next Generation Spectral Library

NASA Technical Reports Server (NTRS)

Heap, Sally

2010-01-01

Hubble's Next Generation Spectral Library (NGSL) consists of R approximately 1000 spectra of 374 stars of assorted temperature, gravity, and metallicity. We are presently working to determine the atmospheric and fundamental parameters of the stars from the NGSL spectra themselves via full-spectrum fitting of model spectra to the observed (extinction-corrected) spectrum over the full wavelength range, 0.2-1.0 micron. We use two grids of model spectra for this purpose: the very low-resolution spectral grid from Castelli-Kurucz (2004), and the grid from MARCS (2008). Both the observed spectrum and the MARCS spectra are first degraded in resolution to match the very low resolution of the Castelli-Kurucz models, so that our fitting technique is the same for both model grids. We will present our preliminary results with a comparison with those from the Sloan/Segue Stellar Parameter Pipeline, ELODIE, and MILES, etc.

Single-shot three-dimensional reconstruction based on structured light line pattern

NASA Astrophysics Data System (ADS)

Wang, ZhenZhou; Yang, YongMing

2018-07-01

Reconstruction of the object by single-shot is of great importance in many applications, in which the object is moving or its shape is non-rigid and changes irregularly. In this paper, we propose a single-shot structured light 3D imaging technique that calculates the phase map from the distorted line pattern. This technique makes use of the image processing techniques to segment and cluster the projected structured light line pattern from one single captured image. The coordinates of the clustered lines are extracted to form a low-resolution phase matrix which is then transformed to full-resolution phase map by spline interpolation. The 3D shape of the object is computed from the full-resolution phase map and the 2D camera coordinates. Experimental results show that the proposed method was able to reconstruct the three-dimensional shape of the object robustly from one single image.

Full-wave multiscale anisotropy tomography in Southern California

NASA Astrophysics Data System (ADS)

Lin, Yu-Pin; Zhao, Li; Hung, Shu-Huei

2014-12-01

Understanding the spatial variation of anisotropy in the upper mantle is important for characterizing the lithospheric deformation and mantle flow dynamics. In this study, we apply a full-wave approach to image the upper-mantle anisotropy in Southern California using 5954 SKS splitting data. Three-dimensional sensitivity kernels combined with a wavelet-based model parameterization are adopted in a multiscale inversion. Spatial resolution lengths are estimated based on a statistical resolution matrix approach, showing a finest resolution length of ~25 km in regions with densely distributed stations. The anisotropic model displays structural fabric in relation to surface geologic features such as the Salton Trough, the Transverse Ranges, and the San Andreas Fault. The depth variation of anisotropy does not suggest a lithosphere-asthenosphere decoupling. At long wavelengths, the fast directions of anisotropy are aligned with the absolute plate motion inside the Pacific and North American plates.

New Processing of Spaceborne Imaging Radar-C (SIR-C) Data

NASA Astrophysics Data System (ADS)

Meyer, F. J.; Gracheva, V.; Arko, S. A.; Labelle-Hamer, A. L.

2017-12-01

The Spaceborne Imaging Radar-C (SIR-C) was a radar system, which successfully operated on two separate shuttle missions in April and October 1994. During these two missions, a total of 143 hours of radar data were recorded. SIR-C was the first multifrequency and polarimetric spaceborne radar system, operating in dual frequency (L- and C- band) and with quad-polarization. SIR-C had a variety of different operating modes, which are innovative even from today's point of view. Depending on the mode, it was possible to acquire data with different polarizations and carrier frequency combinations. Additionally, different swaths and bandwidths could be used during the data collection and it was possible to receive data with two antennas in the along-track direction.The United States Geological Survey (USGS) distributes the synthetic aperture radar (SAR) images as single-look complex (SLC) and multi-look complex (MLC) products. Unfortunately, since June 2005 the SIR-C processor has been inoperable and not repairable. All acquired SLC and MLC images were processed with a course resolution of 100 m with the goal of generating a quick look. These images are however not well suited for scientific analysis. Only a small percentage of the acquired data has been processed as full resolution SAR images and the unprocessed high resolution data cannot be processed any more at the moment.At the Alaska Satellite Facility (ASF) a new processor was developed to process binary SIR-C data to full resolution SAR images. ASF is planning to process the entire recoverable SIR-C archive to full resolution SLCs, MLCs and high resolution geocoded image products. ASF will make these products available to the science community through their existing data archiving and distribution system.The final paper will describe the new processor and analyze the challenges of reprocessing the SIR-C data.

Picosecond resolution on relativistic heavy ions' time-of-flight measurement

NASA Astrophysics Data System (ADS)

Ebran, A.; Taieb, J.; Belier, G.; Chatillon, A.; Laurent, B.; Martin, J.-F.; Pellereau, E.

2013-11-01

We developed a time-of-flight measurement system for relativistic heavy ions with a requested resolution of 40 ps Full Width Half Maximum. Such a resolution is mandatory to assign the correct mass number to every fission fragment, identified using the Bρ-ToF-ΔE method with the recoil spectrometer designed for the SOFIA experiment-which hold very recently at GSI. To achieve such a performance, fast plastic scintillators read-out by dedicated photomultiplier tubes were chosen among other possible options. We have led several test-measurements from 2009 to 2011, in order to investigate: the effect of the addition of a quenching molecule in the scintillator's matrix, the influence of the detector's size and the impact of the photomultiplier tube. The contribution of the dedicated electronics is also characterized. Time-of-flight measurements were performed realized with electron pulses and relativistic heavy ions, respectively provided by the LASER driven electron-accelerator (ELSA) at CEA-DAM Ile-de-France and by the SIS18/FRS facility at GSI. The reported results exhibit a time resolution better than 20 ps Full Width Half Maximum reached with the last prototype at GSI with an Uranium beam. These results confirm that the SOFIA experiment should enable the measurement of the relativistic fission fragments' time-of-flight with the requested resolution.

Estimation of Sea Ice Thickness Distributions through the Combination of Snow Depth and Satellite Laser Altimetry Data

NASA Technical Reports Server (NTRS)

Kurtz, Nathan T.; Markus, Thorsten; Cavalieri, Donald J.; Sparling, Lynn C.; Krabill, William B.; Gasiewski, Albin J.; Sonntag, John G.

2009-01-01

Combinations of sea ice freeboard and snow depth measurements from satellite data have the potential to provide a means to derive global sea ice thickness values. However, large differences in spatial coverage and resolution between the measurements lead to uncertainties when combining the data. High resolution airborne laser altimeter retrievals of snow-ice freeboard and passive microwave retrievals of snow depth taken in March 2006 provide insight into the spatial variability of these quantities as well as optimal methods for combining high resolution satellite altimeter measurements with low resolution snow depth data. The aircraft measurements show a relationship between freeboard and snow depth for thin ice allowing the development of a method for estimating sea ice thickness from satellite laser altimetry data at their full spatial resolution. This method is used to estimate snow and ice thicknesses for the Arctic basin through the combination of freeboard data from ICESat, snow depth data over first-year ice from AMSR-E, and snow depth over multiyear ice from climatological data. Due to the non-linear dependence of heat flux on ice thickness, the impact on heat flux calculations when maintaining the full resolution of the ICESat data for ice thickness estimates is explored for typical winter conditions. Calculations of the basin-wide mean heat flux and ice growth rate using snow and ice thickness values at the 70 m spatial resolution of ICESat are found to be approximately one-third higher than those calculated from 25 km mean ice thickness values.

[Study on the effect of solar spectra on the retrieval of atmospheric CO2 concentration using high resolution absorption spectra].

PubMed

Hu, Zhen-Hua; Huang, Teng; Wang, Ying-Ping; Ding, Lei; Zheng, Hai-Yang; Fang, Li

2011-06-01

Taking solar source as radiation in the near-infrared high-resolution absorption spectrum is widely used in remote sensing of atmospheric parameters. The present paper will take retrieval of the concentration of CO2 for example, and study the effect of solar spectra resolution. Retrieving concentrations of CO2 by using high resolution absorption spectra, a method which uses the program provided by AER to calculate the solar spectra at the top of atmosphere as radiation and combine with the HRATS (high resolution atmospheric transmission simulation) to simulate retrieving concentration of CO2. Numerical simulation shows that the accuracy of solar spectrum is important to retrieval, especially in the hyper-resolution spectral retrieavl, and the error of retrieval concentration has poor linear relation with the resolution of observation, but there is a tendency that the decrease in the resolution requires low resolution of solar spectrum. In order to retrieve the concentration of CO2 of atmosphere, the authors' should take full advantage of high-resolution solar spectrum at the top of atmosphere.

Modeled Full-Flight Aircraft Emissions Impacts on Air Quality and Their Sensitivity to Grid Resolution

NASA Astrophysics Data System (ADS)

Vennam, L. P.; Vizuete, W.; Talgo, K.; Omary, M.; Binkowski, F. S.; Xing, J.; Mathur, R.; Arunachalam, S.

2017-12-01

Aviation is a unique anthropogenic source with four-dimensional varying emissions, peaking at cruise altitudes (9-12 km). Aircraft emission budgets in the upper troposphere lower stratosphere region and their potential impacts on upper troposphere and surface air quality are not well understood. Our key objective is to use chemical transport models (with prescribed meteorology) to predict aircraft emissions impacts on the troposphere and surface air quality. We quantified the importance of including full-flight intercontinental emissions and increased horizontal grid resolution. The full-flight aviation emissions in the Northern Hemisphere contributed 1.3% (mean, min-max: 0.46, 0.3-0.5 ppbv) and 0.2% (0.013, 0.004-0.02 μg/m3) of total O3 and PM2.5 concentrations at the surface, with Europe showing slightly higher impacts (1.9% (O3 0.69, 0.5-0.85 ppbv) and 0.5% (PM2.5 0.03, 0.01-0.05 μg/m3)) than North America (NA) and East Asia. We computed seasonal aviation-attributable mass flux vertical profiles and aviation perturbations along isentropic surfaces to quantify the transport of cruise altitude emissions at the hemispheric scale. The comparison of coarse (108 × 108 km2) and fine (36 × 36 km2) grid resolutions in NA showed 70 times and 13 times higher aviation impacts for O3 and PM2.5 in coarser domain. These differences are mainly due to the inability of the coarse resolution simulation to capture nonlinearities in chemical processes near airport locations and other urban areas. Future global studies quantifying aircraft contributions should consider model resolution and perhaps use finer scales near major aviation source regions.

Modeled Full-Flight Aircraft Emissions Impacts on Air Quality and Their Sensitivity to Grid Resolution

PubMed Central

Vennam, L. P.; Vizuete, W.; Talgo, K.; Omary, M.; Binkowski, F. S.; Xing, J.; Mathur, R.; Arunachalam, S.

2018-01-01

Aviation is a unique anthropogenic source with four-dimensional varying emissions, peaking at cruise altitudes (9–12 km). Aircraft emission budgets in the upper troposphere lower stratosphere region and their potential impacts on upper troposphere and surface air quality are not well understood. Our key objective is to use chemical transport models (with prescribed meteorology) to predict aircraft emissions impacts on the troposphere and surface air quality. We quantified the importance of including full-flight intercontinental emissions and increased horizontal grid resolution. The full-flight aviation emissions in the Northern Hemisphere contributed ~1.3% (mean, min–max: 0.46, 0.3–0.5 ppbv) and 0.2% (0.013, 0.004–0.02 μg/m3) of total O3 and PM2.5 concentrations at the surface, with Europe showing slightly higher impacts (1.9% (O3 0.69, 0.5–0.85 ppbv) and 0.5% (PM2.5 0.03, 0.01–0.05 μg/m3)) than North America (NA) and East Asia. We computed seasonal aviation-attributable mass flux vertical profiles and aviation perturbations along isentropic surfaces to quantify the transport of cruise altitude emissions at the hemispheric scale. The comparison of coarse (108 × 108 km2) and fine (36 × 36 km2) grid resolutions in NA showed ~70 times and ~13 times higher aviation impacts for O3 and PM2.5 in coarser domain. These differences are mainly due to the inability of the coarse resolution simulation to capture nonlinearities in chemical processes near airport locations and other urban areas. Future global studies quantifying aircraft contributions should consider model resolution and perhaps use finer scales near major aviation source regions. PMID:29707471

Modeled Full-Flight Aircraft Emissions Impacts on Air Quality and Their Sensitivity to Grid Resolution.

PubMed

Vennam, L P; Vizuete, W; Talgo, K; Omary, M; Binkowski, F S; Xing, J; Mathur, R; Arunachalam, S

2017-01-01

Aviation is a unique anthropogenic source with four-dimensional varying emissions, peaking at cruise altitudes (9-12 km). Aircraft emission budgets in the upper troposphere lower stratosphere region and their potential impacts on upper troposphere and surface air quality are not well understood. Our key objective is to use chemical transport models (with prescribed meteorology) to predict aircraft emissions impacts on the troposphere and surface air quality. We quantified the importance of including full-flight intercontinental emissions and increased horizontal grid resolution. The full-flight aviation emissions in the Northern Hemisphere contributed ~1.3% (mean, min-max: 0.46, 0.3-0.5 ppbv) and 0.2% (0.013, 0.004-0.02 μg/m 3 ) of total O 3 and PM 2.5 concentrations at the surface, with Europe showing slightly higher impacts (1.9% (O 3 0.69, 0.5-0.85 ppbv) and 0.5% (PM 2.5 0.03, 0.01-0.05 μg/m 3 )) than North America (NA) and East Asia. We computed seasonal aviation-attributable mass flux vertical profiles and aviation perturbations along isentropic surfaces to quantify the transport of cruise altitude emissions at the hemispheric scale. The comparison of coarse (108 × 108 km 2 ) and fine (36 × 36 km 2 ) grid resolutions in NA showed ~70 times and ~13 times higher aviation impacts for O 3 and PM 2.5 in coarser domain. These differences are mainly due to the inability of the coarse resolution simulation to capture nonlinearities in chemical processes near airport locations and other urban areas. Future global studies quantifying aircraft contributions should consider model resolution and perhaps use finer scales near major aviation source regions.

γ-ray telescopes using conversions to e+e- pairs: event generators, angular resolution and polarimetry

NASA Astrophysics Data System (ADS)

Gros, P.; Bernard, D.

2017-02-01

We benchmark various available event generators in Geant4 and EGS5 in the light of ongoing projects for high angular-resolution pair-conversion telescopes at low energy. We compare the distributions of key kinematic variables extracted from the geometry of the three final state particles. We validate and use as reference an exact generator using the full 5D differential cross-section of the conversion process. We focus in particular on the effect of the unmeasured recoiling nucleus on the angular resolution. We show that for high resolution trackers, the choice of the generator affects the estimated resolution of the telescope. We also show that the current available generator are unable to describe accurately a linearly polarised photon source.

Single image super-resolution reconstruction algorithm based on eage selection

NASA Astrophysics Data System (ADS)

Zhang, Yaolan; Liu, Yijun

2017-05-01

Super-resolution (SR) has become more important, because it can generate high-quality high-resolution (HR) images from low-resolution (LR) input images. At present, there are a lot of work is concentrated on developing sophisticated image priors to improve the image quality, while taking much less attention to estimating and incorporating the blur model that can also impact the reconstruction results. We present a new reconstruction method based on eager selection. This method takes full account of the factors that affect the blur kernel estimation and accurately estimating the blur process. When comparing with the state-of-the-art methods, our method has comparable performance.

Resolution of Oculomotor Nerve Palsy Secondary to Posterior Communicating Artery Aneurysms: Comparison of Clipping and Coiling.

PubMed

McCracken, D Jay; Lovasik, Brendan P; McCracken, Courtney E; Caplan, Justin M; Turan, Nefize; Nogueira, Raul G; Cawley, C Michael; Dion, Jacques E; Tamargo, Rafael J; Barrow, Daniel L; Pradilla, Gustavo

2015-12-01

Previous studies have attempted to determine the best treatment for oculomotor nerve palsy (ONP) secondary to posterior communicating artery (PCoA) aneurysms, but have been limited by small sample sizes and limited treatment. To analyze the treatment of ONP secondary to PCoA with both coiling and clipping in ruptured and unruptured aneurysms. Data from 2 large academic centers was retrospectively collected over 22 years, yielding a total of 93 patients with ONP secondary to PCoA aneurysms. These patients were combined with 321 patients from the literature review for large data analyses. Onset symptoms, recovery, and time to resolution were evaluated with respect to treatment and aneurysm rupture status. For all patients presenting with ONP (n = 414) 56.6% of those treated with microsurgical clipping made a full recovery vs 41.5% of those treated with endovascular coil embolization (P = .02). Of patients with a complete ONP (n = 229), full recovery occurred in 47.3% of those treated with clipping but in only 20% of those undergoing coiling (P = .01). For patients presenting with ruptured aneurysms (n = 130), full recovery occurred in 70.9% compared with 49.3% coiled patients (P = .01). Additionally, although patients with full ONP recovery had a median time to treatment of 4 days, those without full ONP recovery had a median time to treatment of 7 days (P = .01). Patients with ONP secondary to PCoA aneurysms treated with clipping showed higher rates of full ONP resolution than patients treated with coil embolization. Larger prospective studies are needed to determine the true potential of recovery associated with each treatment. EUH, Emory University HospitalIQR, interquartile rangeJHU, Johns Hopkins UniversitymRS, modified Rankin ScaleONP, oculomotor nerve palsyPCoA, posterior communicating arterySAH, subarachnoid hemorrhage.

Fade to Red

NASA Technical Reports Server (NTRS)

2006-01-01

[figure removed for brevity, see original site] Infrared Andromeda Galaxy (M31) Poster [figure removed for brevity, see original site] [figure removed for brevity, see original site] Stars Dust

This animation shows the Andromeda galaxy, first as seen in visible light by the National Optical Astronomy Observatory, then as seen in infrared by NASA's Spitzer Space Telescope.

The visible-light image highlights the galaxy's population of about one trillion stars. The stars are so crammed into its core that this region blazes with bright starlight.

In contrast, the false-colored Spitzer view reveals red waves of dust against a more tranquil sea of blue stars. The dust lanes can be seen twirling all the way into the galaxy's center. This dust is warmed by young stars and shines at infrared wavelengths , which are represented in red. The blue color signifies shorter-wavelength infrared light primarily from older stars.

The Andromeda galaxy, also known affectionately by astronomers as Messier 31, is located 2.5 million light-years away in the constellation Andromeda. It is the closest major galaxy to the Milky Way, making it the ideal specimen for carefully examining the nature of galaxies. On a clear, dark night, the galaxy can be spotted with the naked eye as a fuzzy blob.

Andromeda's entire disk spans about 260,000 light-years, which means that a light beam would take 260,000 years to travel from one end of the galaxy to the other. By comparison, the Milky Way is about 100,000 light-years across. When viewed from Earth, Andromeda occupies a portion of the sky equivalent to seven full moons.

Because this galaxy is so large, the infrared images had to be stitched together out of about 3,000 separate Spitzer exposures. The light detected by Spitzer's infrared array camera at 3.6 and 4.5 microns is sensitive mostly to starlight and is shown in blue and green, respectively. The 8-micron light shows warm dust and is shown in red. The contribution from starlight has been subtracted from the 8-micron image to better highlight the dust structures.

Note: The size of the Full-Res TIFF for the still image is 14772 samples x 4953 lines.

Community Radiative Transfer Model Applications - A Study of the Retrieval of Trace Gases in the Atmosphere from Cross-track Infrared Sounder (CrIS) Data of a Full-spectral Resolution

NASA Astrophysics Data System (ADS)

Liu, Q.; Nalli, N. R.; Tan, C.; Zhang, K.; Iturbide, F.; Wilson, M.; Zhou, L.

2015-12-01

The Community Radiative Transfer Model (CRTM) [3] operationally supports satellite radiance assimilation for weather forecasting, sensor data verification, and the retrievals of satellite products. The CRTM has been applied to UV and visible sensors, infrared and microwave sensors. The paper will demonstrate the applications of the CRTM, in particular radiative transfer in the retrieva algorithm. The NOAA Unique CrIS/ATMS Processing System (NUCAPS) operationally generates vertical profiles of atmospheric temperature (AVTP) and moisture (AVMP) from Suomi NPP Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) measurements. Current operational CrIS data have reduced spectral resolution: 1.25 cm-1 for a middle wave band and 2.5 cm-1 for a short-wave wave band [1]. The reduced spectral data largely degraded the retrieval accuracy of trace gases. CrIS full spectral data are also available now which have single spectral resolution of 0.625 cm-1 for all of the three bands: long-wave band, middle wave band, and short-wave band. The CrIS full-spectral resolution data is critical to the retrieval of trace gases such as O3, CO [2], CO2, and CH4. In this paper, we use the Community Radiative Transfer Model (CRTM) to study the impact of the CrIS spectral resolution on the retrieval accuracy of trace gases. The newly released CRTM version 2.2.1 can simulates Hamming-apodized CrIS radiance of a full-spectral resolution. We developed a small utility that can convert the CRTM simulated radiance to un-apodized radiance. The latter has better spectral information which can be helpful to the retrievals of the trace gases. The retrievals will be validated using both NWP model data as well as the data collected during AEROSE expeditions [4]. We will also discuss the sensitivity on trace gases between apodized and un-apodized radiances. References[1] Gambacorta, A., et al.(2013), IEEE Lett., 11(9), doi:10.1109/LGRS.2014.230364, 1639-1643. [2] Han, Y., et al. (2013), JGR.,118, 12,734-12,748, doi:10.1002/2013JD020344. [3] Liu, Q., and S. Boukabara (2013), Remote Sen. Environ., 140 (2014) 744-754. [4] Nalli, N. R. et al(2011) . Bulletin of the American Meteorological Society, (92), 765-789.

Overview of the data analysis and new micro-pattern gas detector development for the Active Target Time Projection Chamber (AT-TPC) project.

NASA Astrophysics Data System (ADS)

Ayyad, Yassid; Mittig, Wolfgang; Bazin, Daniel; Cortesi, Marco

2017-07-01

The Active Target Time Projection Chamber (AT-TPC) project at the NSCL (National Superconducting Cyclotron Laboratory, Michigan State University) is a novel active target detector tailored for low-energy nuclear reactions in inverse kinematics with radioactive ion beams. The AT-TPC allows for a full three dimensional reconstruction of the reaction and provides high luminosity without degradation of resolution by the thickness of the target. Since all the particles (and also the reaction vertex) are tracked inside the detector, the AT-TPC has full 4π efficiency. The AT-TPC can operate under a magnetic field (2 T) that improves the identification of the particles and the energy resolution through the measurement of the magnetic rigidity. Another important characteristic of the AT-TPC is the high-gain operation achieved by the hybrid thick Gas Electron Multipliers (THGEM)-Micromegas pad plane, that allow operation also in pure elemental gas. These two features make the AT-TPC a unique high resolution spectrometer with full acceptance for nuclear physics reactions. This work presents an overview of the project, focused on the data analysis and the development of new micro-pattern gas detectors.

Equally sloped tomography based X-ray full-field nano-CT at Shanghai Synchrotron Radiation Facility

NASA Astrophysics Data System (ADS)

Wang, Yudan; Ren, Yuqi; Zhou, Guangzhao; Du, Guohao; Xie, Honglan; Deng, Biao; Xiao, Tiqiao

2018-07-01

X-ray full-field nano-computed tomography (nano-CT) has non-destructive three-dimensional imaging capabilities with high spatial resolution, and has been widely applied to investigate morphology and structures in various areas. Conventional tomography reconstructs a 3D object from a large number of equal-angle projections. For nano-CT, it takes long collecting time due to the large projection numbers and long exposure time. Here, equally-sloped tomography (EST) based nano-CT was implemented and constructed on X-ray imaging beamline at the Shanghai Synchrotron Radiation Facility (SSRF) to overcome or alleviate these difficulties. Preliminary results show that hard TXM with the spatial resolution of 100 nm and the EST-based nano-CT with the ability of 3D nano non-destructive characterization have been realized. This technique promotes hard X-ray imaging capability to nano scales at SSRF and could have applications in many fields including nanomaterials, new energy and life sciences. The study will be helpful for the construction of the new full field X-ray nano-imaging beamline with the spatial resolution of 20 nm at SSRF phase II project.

Development of a new screening method for the detection of antibiotic residues in muscle tissues using liquid chromatography and high resolution mass spectrometry with a LC-LTQ-Orbitrap instrument.

PubMed

Hurtaud-Pessel, D; Jagadeshwar-Reddy, T; Verdon, E

2011-10-01

A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed for screening meat for a wide range of antibiotics used in veterinary medicine. Full-scan mode under high resolution mass spectral conditions using an LTQ-Orbitrap mass spectrometer with resolving power 60,000 full width at half maximum (FWHM) was applied for analysis of the samples. Samples were prepared using two extraction protocols prior to LC-HRMS analysis. The scope of the method focuses on screening the following main families of antibacterial veterinary drugs: penicillins, cephalosporins, sulfonamides, macrolides, tetracyclines, aminoglucosides and quinolones. Compounds were successfully identified in spiked samples from their accurate mass and LC retention times from the acquired full-scan chromatogram. Automated data processing using ToxId software allowed rapid treatment of the data. Analyses of muscle tissues from real samples collected from antibiotic-treated animals was carried out using the above methodology and antibiotic residues were identified unambiguously. Further analysis of the data for real samples allowed the identification of the targeted antibiotic residues but also non-targeted compounds, such as some of their metabolites.

The significance of spatial resolution: Identifying forest cover from satellite data

Treesearch

Dumitru Salajanu; Charles E. Olson

2001-01-01

Twenty-five years ago, a National Academy of Sciences report identified species identification as a requirement if satellite data are to reach their full potential in forest inventory and monitoring; the report suggested that improving spatial resolution to 10 meters would probably be required (Committee on Remote Sensing Programs for Earth Resource Surveys [CORSPERS]...

Low resolution radar digital interface. [with data recorder for precipitation measurements

NASA Technical Reports Server (NTRS)

1973-01-01

This document describes the design and operation of a low resolution radar data recording system for precipitation measurements. This system records a full azimuth scan on seven track magnetic tapes every five minutes. It is designed to operate on a continuous basis with operator intervention required only for changing tape reels and calibration.

A study of overflow simulations using MPAS-Ocean: Vertical grids, resolution, and viscosity

NASA Astrophysics Data System (ADS)

Reckinger, Shanon M.; Petersen, Mark R.; Reckinger, Scott J.

2015-12-01

MPAS-Ocean is used to simulate an idealized, density-driven overflow using the dynamics of overflow mixing and entrainment (DOME) setup. Numerical simulations are carried out using three of the vertical coordinate types available in MPAS-Ocean, including z-star with partial bottom cells, z-star with full cells, and sigma coordinates. The results are first benchmarked against other models, including the MITgcm's z-coordinate model and HIM's isopycnal coordinate model, which are used to set the base case used for this work. A full parameter study is presented that looks at how sensitive overflow simulations are to vertical grid type, resolution, and viscosity. Horizontal resolutions with 50 km grid cells are under-resolved and produce poor results, regardless of other parameter settings. Vertical grids ranging in thickness from 15 m to 120 m were tested. A horizontal resolution of 10 km and a vertical resolution of 60 m are sufficient to resolve the mesoscale dynamics of the DOME configuration, which mimics real-world overflow parameters. Mixing and final buoyancy are least sensitive to horizontal viscosity, but strongly sensitive to vertical viscosity. This suggests that vertical viscosity could be adjusted in overflow water formation regions to influence mixing and product water characteristics. Lastly, the study shows that sigma coordinates produce much less mixing than z-type coordinates, resulting in heavier plumes that go further down slope. Sigma coordinates are less sensitive to changes in resolution but as sensitive to vertical viscosity compared to z-coordinates.

Coupled Neutronics Thermal-Hydraulic Solution of a Full-Core PWR Using VERA-CS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clarno, Kevin T; Palmtag, Scott; Davidson, Gregory G

2014-01-01

The Consortium for Advanced Simulation of Light Water Reactors (CASL) is developing a core simulator called VERA-CS to model operating PWR reactors with high resolution. This paper describes how the development of VERA-CS is being driven by a set of progression benchmark problems that specify the delivery of useful capability in discrete steps. As part of this development, this paper will describe the current capability of VERA-CS to perform a multiphysics simulation of an operating PWR at Hot Full Power (HFP) conditions using a set of existing computer codes coupled together in a novel method. Results for several single-assembly casesmore » are shown that demonstrate coupling for different boron concentrations and power levels. Finally, high-resolution results are shown for a full-core PWR reactor modeled in quarter-symmetry.« less

Differential Deposition for Surface Figure Corrections in Grazing Incidence X-Ray Optics

NASA Technical Reports Server (NTRS)

Ramsey, Brian D.; Kilaru, Kiranmayee; Atkins, Carolyn; Gubarev, Mikhail V.; Broadway, David M.

2015-01-01

Differential deposition corrects the low- and mid- spatial-frequency deviations in the axial figure of Wolter-type grazing incidence X-ray optics. Figure deviations is one of the major contributors to the achievable angular resolution. Minimizing figure errors can significantly improve the imaging quality of X-ray optics. Material of varying thickness is selectively deposited, using DC magnetron sputtering, along the length of optic to minimize figure deviations. Custom vacuum chambers are built that can incorporate full-shell and segmented Xray optics. Metrology data of preliminary corrections on a single meridian of full-shell x-ray optics show an improvement of mid-spatial frequencies from 6.7 to 1.8 arc secs HPD. Efforts are in progress to correct a full-shell and segmented optics and to verify angular-resolution improvement with X-ray testing.

SCIFIO: an extensible framework to support scientific image formats.

PubMed

Hiner, Mark C; Rueden, Curtis T; Eliceiri, Kevin W

2016-12-07

No gold standard exists in the world of scientific image acquisition; a proliferation of instruments each with its own proprietary data format has made out-of-the-box sharing of that data nearly impossible. In the field of light microscopy, the Bio-Formats library was designed to translate such proprietary data formats to a common, open-source schema, enabling sharing and reproduction of scientific results. While Bio-Formats has proved successful for microscopy images, the greater scientific community was lacking a domain-independent framework for format translation. SCIFIO (SCientific Image Format Input and Output) is presented as a freely available, open-source library unifying the mechanisms of reading and writing image data. The core of SCIFIO is its modular definition of formats, the design of which clearly outlines the components of image I/O to encourage extensibility, facilitated by the dynamic discovery of the SciJava plugin framework. SCIFIO is structured to support coexistence of multiple domain-specific open exchange formats, such as Bio-Formats' OME-TIFF, within a unified environment. SCIFIO is a freely available software library developed to standardize the process of reading and writing scientific image formats.

Digital soils survey map of the Patagonia Mountains, Arizona

USGS Publications Warehouse

Norman, Laura; Wissler, Craig; Guertin, D. Phillip; Gray, Floyd

2002-01-01

The ‘Soil Survey of Santa Cruz and Parts of Cochise and Pima Counties, Arizona,' a product of the USDA’s Soil Conservation Service and the Forest Service in cooperation with the Arizona Agricultural Experiment Station, released in 1979, was created according to the site conditions in 1971, when soil scientists identified soils types on aerial photographs. The scale at which these maps were published is 1:20,000. These soil maps were automated for incorporation into the hydrologic modeling within a GIS. The aerial photos onto which the soils units were drawn had not been orthoganalized, and contained distortion. A total of 15 maps composed the study area. These maps were scanned into TIFF format using an 8-bit black and white drum scanner at 100 dpi. The images were imported into ERDAS IMAGINE and the white borders were removed through subset decollaring processes. Five CD-ROM’s containing Digital Orthophoto Quarter Quads (DOQQ’s) were used to register and rectify the scanned soils maps. Polygonal data was then attributed according to the datasets.

PredictABEL: an R package for the assessment of risk prediction models.

PubMed

Kundu, Suman; Aulchenko, Yurii S; van Duijn, Cornelia M; Janssens, A Cecile J W

2011-04-01

The rapid identification of genetic markers for multifactorial diseases from genome-wide association studies is fuelling interest in investigating the predictive ability and health care utility of genetic risk models. Various measures are available for the assessment of risk prediction models, each addressing a different aspect of performance and utility. We developed PredictABEL, a package in R that covers descriptive tables, measures and figures that are used in the analysis of risk prediction studies such as measures of model fit, predictive ability and clinical utility, and risk distributions, calibration plot and the receiver operating characteristic plot. Tables and figures are saved as separate files in a user-specified format, which include publication-quality EPS and TIFF formats. All figures are available in a ready-made layout, but they can be customized to the preferences of the user. The package has been developed for the analysis of genetic risk prediction studies, but can also be used for studies that only include non-genetic risk factors. PredictABEL is freely available at the websites of GenABEL ( http://www.genabel.org ) and CRAN ( http://cran.r-project.org/).

Map showing inventory and regional susceptibility for Holocene debris flows, and related fast-moving landslides in the conterminous United States

USGS Publications Warehouse

Brabb, Earl E.; Colgan, Joseph P.; Best, Timothy C.

2000-01-01

Introduction Debris flows, debris avalanches, mud flows and lahars are fast-moving landslides that occur in a wide variety of environments throughout the world. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. This map represents a significant effort to compile the locations of known debris flows in United Stated and predict where future flows might occur. The files 'dfipoint.e00' and 'dfipoly.e00' contain the locations of over 6600 debris flows from published and unpublished sources. The locations are referenced by numbers that correspond to entries in a bibliography, which is part of the pamphlet 'mf2329pamphlet.pdf'. The areas of possible future debris flows are shown in the file 'susceptibility.tif', which is a georeferenced TIFF file that can be opened in an image editing program or imported into a GIS system like ARC/INFO. All other databases are in ARC/INFO export (.e00) format.

Lossless Data Embedding—New Paradigm in Digital Watermarking

NASA Astrophysics Data System (ADS)

Fridrich, Jessica; Goljan, Miroslav; Du, Rui

2002-12-01

One common drawback of virtually all current data embedding methods is the fact that the original image is inevitably distorted due to data embedding itself. This distortion typically cannot be removed completely due to quantization, bit-replacement, or truncation at the grayscales 0 and 255. Although the distortion is often quite small and perceptual models are used to minimize its visibility, the distortion may not be acceptable for medical imagery (for legal reasons) or for military images inspected under nonstandard viewing conditions (after enhancement or extreme zoom). In this paper, we introduce a new paradigm for data embedding in images (lossless data embedding) that has the property that the distortion due to embedding can be completely removed from the watermarked image after the embedded data has been extracted. We present lossless embedding methods for the uncompressed formats (BMP, TIFF) and for the JPEG format. We also show how the concept of lossless data embedding can be used as a powerful tool to achieve a variety of nontrivial tasks, including lossless authentication using fragile watermarks, steganalysis of LSB embedding, and distortion-free robust watermarking.

Landsat 7 thermal-IR image sharpening using an artificial neural network and sensor model

USGS Publications Warehouse

Lemeshewsky, G.P.; Schowengerdt, R.A.; ,

2001-01-01

The enhanced thematic mapper (plus) (ETM+) instrument on Landsat 7 shares the same basic design as the TM sensors on Landsats 4 and 5, with some significant improvements. In common are six multispectral bands with a 30-m ground-projected instantaneous field of view (GIFOV). However, the thermaL-IR (TIR) band now has a 60-m GIFOV, instead of 120-m. Also, a 15-m panchromatic band has been added. The artificial neural network (NN) image sharpening method described here uses data from the higher spatial resolution ETM+ bands to enhance (sharpen) the spatial resolution of the TIR imagery. It is based on an assumed correlation over multiple scales of resolution, between image edge contrast patterns in the TIR band and several other spectral bands. A multilayer, feedforward NN is trained to approximate TIR data at 60m, given degraded (from 30-m to 60-m) spatial resolution input from spectral bands 7, 5, and 2. After training, the NN output for full-resolution input generates an approximation of a TIR image at 30-m resolution. Two methods are used to degrade the spatial resolution of the imagery used for NN training, and the corresponding sharpening results are compared. One degradation method uses a published sensor transfer function (TF) for Landsat 5 to simulate sensor coarser resolution imagery from higher resolution imagery. For comparison, the second degradation method is simply Gaussian low pass filtering and subsampling, wherein the Gaussian filter approximates the full width at half maximum amplitude characteristics of the TF-based spatial filter. Two fixed-size NNs (that is, number of weights and processing elements) were trained separately with the degraded resolution data, and the sharpening results compared. The comparison evaluates the relative influence of the degradation technique employed and whether or not it is desirable to incorporate a sensor TF model. Preliminary results indicate some improvements for the sensor model-based technique. Further evaluation using a higher resolution reference image and strict application of sensor model to data is recommended.

Three dimensional canonical singularity and five dimensional N = 1 SCFT

NASA Astrophysics Data System (ADS)

Xie, Dan; Yau, Shing-Tung

2017-06-01

We conjecture that every three dimensional canonical singularity defines a five dimensional N = 1 SCFT. Flavor symmetry can be found from singularity structure: non-abelian flavor symmetry is read from the singularity type over one dimensional singular locus. The dimension of Coulomb branch is given by the number of compact crepant divisors from a crepant resolution of singularity. The detailed structure of Coulomb branch is described as follows: a) a chamber of Coulomb branch is described by a crepant resolution, and this chamber is given by its Nef cone and the prepotential is computed from triple intersection numbers; b) Crepant resolution is not unique and different resolutions are related by flops; Nef cones from crepant resolutions form a fan which is claimed to be the full Coulomb branch.

Enhanced High Resolution RBS System

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 A ring 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 registered accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic datamore » 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.« less

Resolution No. 598-87, Regulations for the Functioning of the Land Tenure Registry, 27 October 1987.

PubMed

1988-01-01

This Resolution sets forth Regulations for the Land Tenancy Registry of Cuba. It provides that the Registry is part of a scheme for exercising control over legal land tenure and has the following objectives: maintaining control of national land; determining the legal situation of holders of land; recognizing the number of legal holders of land; furnishing information on acquisition, exploitation, and buildings; issuing certificates; and analyzing and processing records in appeals. Further provisions of the Resolution lay down details about these functions. full text

NOAA Photo Library - Navigating the Collection

Science.gov Websites

will have to change the setting to 800x600 to view the full image without having to scroll from left to view or download the highest resolution image available, click on the message "High Resolution viewing individual images associated with albums. If wishing to view the image ID number of a thumbnail

Finding the best resolution for the Kingman-Tajima coalescent: theory and applications.

PubMed

Sainudiin, Raazesh; Stadler, Tanja; Véber, Amandine

2015-05-01

Many summary statistics currently used in population genetics and in phylogenetics depend only on a rather coarse resolution of the underlying tree (the number of extant lineages, for example). Hence, for computational purposes, working directly on these resolutions appears to be much more efficient. However, this approach seems to have been overlooked in the past. In this paper, we describe six different resolutions of the Kingman-Tajima coalescent together with the corresponding Markov chains, which are essential for inference methods. Two of the resolutions are the well-known n-coalescent and the lineage death process due to Kingman. Two other resolutions were mentioned by Kingman and Tajima, but never explicitly formalized. Another two resolutions are novel, and complete the picture of a multi-resolution coalescent. For all of them, we provide the forward and backward transition probabilities, the probability of visiting a given state as well as the probability of a given realization of the full Markov chain. We also provide a description of the state-space that highlights the computational gain obtained by working with lower-resolution objects. Finally, we give several examples of summary statistics that depend on a coarser resolution of Kingman's coalescent, on which simulations are usually based.

Visually Lossless JPEG 2000 for Remote Image Browsing

PubMed Central

Oh, Han; Bilgin, Ali; Marcellin, Michael

2017-01-01

Image sizes have increased exponentially in recent years. The resulting high-resolution images are often viewed via remote image browsing. Zooming and panning are desirable features in this context, which result in disparate spatial regions of an image being displayed at a variety of (spatial) resolutions. When an image is displayed at a reduced resolution, the quantization step sizes needed for visually lossless quality generally increase. This paper investigates the quantization step sizes needed for visually lossless display as a function of resolution, and proposes a method that effectively incorporates the resulting (multiple) quantization step sizes into a single JPEG2000 codestream. This codestream is JPEG2000 Part 1 compliant and allows for visually lossless decoding at all resolutions natively supported by the wavelet transform as well as arbitrary intermediate resolutions, using only a fraction of the full-resolution codestream. When images are browsed remotely using the JPEG2000 Interactive Protocol (JPIP), the required bandwidth is significantly reduced, as demonstrated by extensive experimental results. PMID:28748112

Refinement procedure for the image alignment in high-resolution electron tomography.

PubMed

Houben, L; Bar Sadan, M

2011-01-01

High-resolution electron tomography from a tilt series of transmission electron microscopy images requires an accurate image alignment procedure in order to maximise the resolution of the tomogram. This is the case in particular for ultra-high resolution where even very small misalignments between individual images can dramatically reduce the fidelity of the resultant reconstruction. A tomographic-reconstruction based and marker-free method is proposed, which uses an iterative optimisation of the tomogram resolution. The method utilises a search algorithm that maximises the contrast in tomogram sub-volumes. Unlike conventional cross-correlation analysis it provides the required correlation over a large tilt angle separation and guarantees a consistent alignment of images for the full range of object tilt angles. An assessment based on experimental reconstructions shows that the marker-free procedure is competitive to the reference of marker-based procedures at lower resolution and yields sub-pixel accuracy even for simulated high-resolution data. Copyright © 2011 Elsevier B.V. All rights reserved.

Multiscale Exploration of Mouse Brain Microstructures Using the Knife-Edge Scanning Microscope Brain Atlas

PubMed Central

Chung, Ji Ryang; Sung, Chul; Mayerich, David; Kwon, Jaerock; Miller, Daniel E.; Huffman, Todd; Keyser, John; Abbott, Louise C.; Choe, Yoonsuck

2011-01-01

Connectomics is the study of the full connection matrix of the brain. Recent advances in high-throughput, high-resolution 3D microscopy methods have enabled the imaging of whole small animal brains at a sub-micrometer resolution, potentially opening the road to full-blown connectomics research. One of the first such instruments to achieve whole-brain-scale imaging at sub-micrometer resolution is the Knife-Edge Scanning Microscope (KESM). KESM whole-brain data sets now include Golgi (neuronal circuits), Nissl (soma distribution), and India ink (vascular networks). KESM data can contribute greatly to connectomics research, since they fill the gap between lower resolution, large volume imaging methods (such as diffusion MRI) and higher resolution, small volume methods (e.g., serial sectioning electron microscopy). Furthermore, KESM data are by their nature multiscale, ranging from the subcellular to the whole organ scale. Due to this, visualization alone is a huge challenge, before we even start worrying about quantitative connectivity analysis. To solve this issue, we developed a web-based neuroinformatics framework for efficient visualization and analysis of the multiscale KESM data sets. In this paper, we will first provide an overview of KESM, then discuss in detail the KESM data sets and the web-based neuroinformatics framework, which is called the KESM brain atlas (KESMBA). Finally, we will discuss the relevance of the KESMBA to connectomics research, and identify challenges and future directions. PMID:22275895

Exploiting MISR products at the full spatial resolution (275m) to document changes in land properties in and around the Kruger National Park, South Africa

NASA Astrophysics Data System (ADS)

Verstraete, M. M.; Hunt, L. A.; Pinty, B.; Clerici, M.; Scholes, R. J.

2009-12-01

The MISR instrument on NASA's Terra platform has been acquiring data globally and continuously for almost 10 years. A wide range of atmospheric and land products are operationally generated at the LaRC ASDC, at spatial resolutions of 1.1 km or coarser. Yet, the intrinsic spatial resolution of that sensor is 275m and 12 out of the 36 spectro-directional data channels are transmitted to the ground segment at that resolution. Recent algorithmic developments have permitted us to reconstruct reasonable estimates of the other 24 channels and to account for atmospheric effects at the full original spatial resolution. Spectro-directional reflectances have been processed to characterize the anisotropy of observed land surfaces and then optimally estimate various geophysical properties of the environment such as the fluxes of radiation in and out of plant canopies, the albedo, FAPAR, etc. These detailed products allow us to investigate ecological and environmental changes in much greater spatial and thematic detail than was previously possible. The paper outlines the various methodological steps implemented and exhibits concrete results for a region of moderate size (280 by 380 km) in South Africa. Practical downstream applications of this approach include monitoring desertification and biomass burning, documenting urbanization or characterizing the phenology of vegetation.

In vivo and ex vivo imaging with ultrahigh resolution full-field OCT

NASA Astrophysics Data System (ADS)

Grieve, Kate; Moneron, Gael; Schwartz, Wilfrid; Boccara, Albert C.; Dubois, Arnaud

2005-08-01

Imaging of in vivo and ex vivo biological samples using full-field optical coherence tomography is demonstrated. Three variations on the original full-field optical coherence tomography instrument are presented, and evaluated in terms of performance. The instruments are based on the Linnik interferometer illuminated by a white light source. Images in the en face orientation are obtained in real-time without scanning by using a two-dimensional parallel detector array. An isotropic resolution capability better than 1 μm is achieved thanks to the use of a broad spectrum source and high numerical aperture microscope objectives. Detection sensitivity up to 90 dB is demonstrated. Image acquisition times as short as 10 μs per en face image are possible. A variety of in vivo and ex vivo imaging applications is explored, particularly in the fields of embryology, ophthalmology and botany.

Further investigation on "A multiplicative regularization for force reconstruction"

NASA Astrophysics Data System (ADS)

Aucejo, M.; De Smet, O.

2018-05-01

We have recently proposed a multiplicative regularization to reconstruct mechanical forces acting on a structure from vibration measurements. This method does not require any selection procedure for choosing the regularization parameter, since the amount of regularization is automatically adjusted throughout an iterative resolution process. The proposed iterative algorithm has been developed with performance and efficiency in mind, but it is actually a simplified version of a full iterative procedure not described in the original paper. The present paper aims at introducing the full resolution algorithm and comparing it with its simplified version in terms of computational efficiency and solution accuracy. In particular, it is shown that both algorithms lead to very similar identified solutions.

A complementary mobile phase approach based on the peak count concept oriented to the full resolution of complex mixtures.

PubMed

Ortín, A; Torres-Lapasió, J R; García-Álvarez-Coque, M C

2011-08-26

Situations of minimal resolution are often found in liquid chromatography, when samples that contain a large number of compounds, or highly similar in terms of structure and/or polarity, are analysed. This makes full resolution with a single separation condition (e.g., mobile phase, gradient or column) unfeasible. In this work, the optimisation of the resolution of such samples in reversed-phase liquid chromatography is approached using two or more isocratic mobile phases with a complementary resolution behaviour (complementary mobile phases, CMPs). Each mobile phase is dedicated to the separation of a group of compounds. The CMPs are selected in such a way that, when the separation is considered globally, all the compounds in the sample are satisfactorily resolved. The search of optimal CMPs can be carried out through a comprehensive examination of the mobile phases in a selected domain. The computation time of this search has been reported to be substantially reduced by application of a genetic algorithm with local search (LOGA). A much simpler approach is here described, which is accessible to non-experts in programming, and offers solutions of the same quality as LOGA, with a similar computation time. The approach makes a sequential search of CMPs based on the peak count concept, which is the number of peaks exceeding a pre-established resolution threshold. The new approach is described using as test sample a mixture of 30 probe compounds, 23 of them with an ionisable character, and the pH and organic solvent contents as experimental factors. Copyright © 2011 Elsevier B.V. All rights reserved.

Image restoration method based on Hilbert transform for full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Na, Jihoon; Choi, Woo June; Choi, Eun Seo; Ryu, Seon Young; Lee, Byeong Ha

2008-01-01

A full-field optical coherence tomography (FF-OCT) system utilizing a simple but novel image restoration method suitable for a high-speed system is demonstrated. An en-face image is retrieved from only two phase-shifted interference fringe images through using the mathematical Hilbert transform. With a thermal light source, a high-resolution FF-OCT system having axial and transverse resolutions of 1 and 2.2 μm, respectively, was implemented. The feasibility of the proposed scheme is confirmed by presenting the obtained en-face images of biological samples such as a piece of garlic and a gold beetle. The proposed method is robust to the error in the amount of the phase shift and does not leave residual fringes. The use of just two interference images and the strong immunity to phase errors provide great advantages in the imaging speed and the system design flexibility of a high-speed high-resolution FF-OCT system.

BOREAS TE-18, 30-m, Radiometrically Rectified Landsat TM Imagery

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Knapp, David

2000-01-01

The BOREAS TE-18 team used a radiometric rectification process to produce standardized DN values for a series of Landsat TM images of the BOREAS SSA and NSA in order to compare images that were collected under different atmospheric conditions. The images for each study area were referenced to an image that had very clear atmospheric qualities. The reference image for the SSA was collected on 02-Sep-1994, while the reference image for the NSA was collected on 21-Jun-1995. the 23 rectified images cover the period of 07-Jul-1985 to 18 Sep-1994 in the SSA and from 22-Jun-1984 to 09-Jun-1994 in the NSA. Each of the reference scenes had coincident atmospheric optical thickness measurements made by RSS-11. The radiometric rectification process is described in more detail by Hall et al. (199 1). The original Landsat TM data were received from CCRS for use in the BOREAS project. The data are stored in binary image-format files. Due to the nature of the radiometric rectification process and copyright issues, these full-resolution images may not be publicly distributed. However, a spatially degraded 60-m resolution version of the images is available on the BOREAS CD-ROM series. See Sections 15 and 16 for information about how to possibly acquire the full resolution data. Information about the full-resolution images is provided in an inventory listing on the CD-ROMs. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Activity Archive Center (DAAC).

Full-field chromatic confocal surface profilometry employing digital micromirror device correspondence for minimizing lateral cross talks

NASA Astrophysics Data System (ADS)

Chen, Liang-Chia; Chang, Yi-Wei; Li, Hau-Wei

2012-08-01

Full-field chromatic confocal surface profilometry employing a digital micromirror device (DMD) for spatial correspondence is proposed to minimize lateral cross-talks between individual detection sensors. Although full-field chromatic confocal profilometry is capable of enhancing measurement efficiency by completely removing time-consuming vertical scanning operation, its vertical measurement resolution and accuracy are still severely affected by the potential sensor lateral cross-talk problem. To overcome this critical bottleneck, a DMD-based chromatic confocal method is developed by employing a specially-designed objective for chromatic light dispersion, and a DMD for lateral pixel correspondence and scanning, thereby reducing the lateral cross-talk influence. Using the chromatic objective, the incident light is dispersed according to a pre-designed detection range of several hundred micrometers, and a full-field reflected light is captured by a three-chip color camera for multi color detection. Using this method, the full width half maximum of the depth response curve can be significantly sharpened, thus improving the vertical measurement resolution and repeatability of the depth detection. From our preliminary experimental evaluation, it is verified that the ±3σ repeatability of the height measurement can be kept within 2% of the overall measurement range.

Coreference annotation and resolution in the Colorado Richly Annotated Full Text (CRAFT) corpus of biomedical journal articles.

PubMed

Cohen, K Bretonnel; Lanfranchi, Arrick; Choi, Miji Joo-Young; Bada, Michael; Baumgartner, William A; Panteleyeva, Natalya; Verspoor, Karin; Palmer, Martha; Hunter, Lawrence E

2017-08-17

Coreference resolution is the task of finding strings in text that have the same referent as other strings. Failures of coreference resolution are a common cause of false negatives in information extraction from the scientific literature. In order to better understand the nature of the phenomenon of coreference in biomedical publications and to increase performance on the task, we annotated the Colorado Richly Annotated Full Text (CRAFT) corpus with coreference relations. The corpus was manually annotated with coreference relations, including identity and appositives for all coreferring base noun phrases. The OntoNotes annotation guidelines, with minor adaptations, were used. Interannotator agreement ranges from 0.480 (entity-based CEAF) to 0.858 (Class-B3), depending on the metric that is used to assess it. The resulting corpus adds nearly 30,000 annotations to the previous release of the CRAFT corpus. Differences from related projects include a much broader definition of markables, connection to extensive annotation of several domain-relevant semantic classes, and connection to complete syntactic annotation. Tool performance was benchmarked on the data. A publicly available out-of-the-box, general-domain coreference resolution system achieved an F-measure of 0.14 (B3), while a simple domain-adapted rule-based system achieved an F-measure of 0.42. An ensemble of the two reached F of 0.46. Following the IDENTITY chains in the data would add 106,263 additional named entities in the full 97-paper corpus, for an increase of 76% percent in the semantic classes of the eight ontologies that have been annotated in earlier versions of the CRAFT corpus. The project produced a large data set for further investigation of coreference and coreference resolution in the scientific literature. The work raised issues in the phenomenon of reference in this domain and genre, and the paper proposes that many mentions that would be considered generic in the general domain are not generic in the biomedical domain due to their referents to specific classes in domain-specific ontologies. The comparison of the performance of a publicly available and well-understood coreference resolution system with a domain-adapted system produced results that are consistent with the notion that the requirements for successful coreference resolution in this genre are quite different from those of the general domain, and also suggest that the baseline performance difference is quite large.

Recent Progress in Adjustable X-ray Optics for Astronomy

NASA Technical Reports Server (NTRS)

Reid, Paul B.; Allured, Ryan; Cotroneo, Vincenzo; McMuldroch, Stuart; Marquez, Vanessa; Schwartz, Daniel A.; Vikhlinin, Alexey; ODell, Stephen L.; Ramsey, Brian; Trolier-McKinstry, Susan;

Comparison of the Effectiveness of Two Forms of the Enhancing Relationships in School Communities Project for Promoting Cooperative Conflict Resolution Education in Australian Primary Schools

ERIC Educational Resources Information Center

Trinder, Margot; Wertheim, Eleanor H.; Freeman, Elizabeth; Sanson, Ann; Richardson, Shanel; Hunt, Sue

2010-01-01

This study evaluated the Enhancing Relationships in School Communities (ERIS) Project which aimed to promote constructive conflict resolution (CR) in Australian primary school communities through professional development for core teams of three-five staff (n = 33 teachers). Twelve schools were randomly assigned to a full intervention (FI) group or…

A resolution strongly supporting the full implementation of United States and international sanctions on Iran and urging the President to continue to strengthen enforcement of sanctions legislation.

THOMAS, 113th Congress

Sen. Graham, Lindsey [R-SC

2013-02-28

Senate - 05/22/2013 Resolution agreed to in Senate with an amendment and with a preamble by Yea-Nay Vote. 99 - 0. Record Vote Number: 133. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

Application of GEM-based detectors in full-field XRF imaging

NASA Astrophysics Data System (ADS)

Dąbrowski, W.; Fiutowski, T.; Frączek, P.; Koperny, S.; Lankosz, M.; Mendys, A.; Mindur, B.; Świentek, K.; Wiącek, P.; Wróbel, P. M.

2016-12-01

X-ray fluorescence spectroscopy (XRF) is a commonly used technique for non-destructive elemental analysis of cultural heritage objects. It can be applied to investigations of provenance of historical objects as well as to studies of art techniques. While the XRF analysis can be easily performed locally using standard available equipment there is a growing interest in imaging of spatial distribution of specific elements. Spatial imaging of elemental distrbutions is usually realised by scanning an object with a narrow focused X-ray excitation beam and measuring characteristic fluorescence radiation using a high energy resolution detector, usually a silicon drift detector. Such a technique, called macro-XRF imaging, is suitable for investigation of flat surfaces but it is time consuming because the spatial resolution is basically determined by the spot size of the beam. Another approach is the full-field XRF, which is based on simultaneous irradiation and imaging of large area of an object. The image of the investigated area is projected by a pinhole camera on a position-sensitive and energy dispersive detector. The infinite depth of field of the pinhole camera allows one, in principle, investigation of non-flat surfaces. One of possible detectors to be employed in full-field XRF imaging is a GEM based detector with 2-dimensional readout. In the paper we report on development of an imaging system equipped with a standard 3-stage GEM detector of 10 × 10 cm2 equipped with readout electronics based on dedicated full-custom ASICs and DAQ system. With a demonstrator system we have obtained 2-D spatial resolution of the order of 100 μm and energy resolution at a level of 20% FWHM for 5.9 keV . Limitations of such a detector due to copper fluorescence radiation excited in the copper-clad drift electrode and GEM foils is discussed and performance of the detector using chromium-clad electrodes is reported.

Multi-Grid and Resolution Full-Wave Tomography and Moment Tensor Inversion (Postprint)

DTIC Science & Technology

2012-06-04

Denver: University of Colorado. Chen, P., L. Zhao, and T.H. Jordan (2007). Full 3D tomography for crustal structure of the Los Angeles Region, Bull...M.J.R. Wortel, and W. Spakman (2006). Subduction history of the Tethyan region derived from seismic tomography and tectonic reconstructions, J. Geophys

Optically sectioned fluorescence endomicroscopy with hybrid-illumination imaging through a flexible fiber bundle.

PubMed

Santos, Silvia; Chu, Kengyeh K; Lim, Daryl; Bozinovic, Nenad; Ford, Tim N; Hourtoule, Claire; Bartoo, Aaron C; Singh, Satish K; Mertz, Jerome

2009-01-01

We present an endomicroscope apparatus that exhibits out-of-focus background rejection based on wide-field illumination through a flexible imaging fiber bundle. Our technique, called HiLo microscopy, involves acquiring two images, one with grid-pattern illumination and another with standard uniform illumination. An evaluation of the image contrast with grid-pattern illumination provides an optically sectioned image with low resolution. This is complemented with high-resolution information from the uniform illumination image, leading to a full-resolution image that is optically sectioned. HiLo endomicroscope movies are presented of fluorescently labeled rat colonic mucosa.

Optically sectioned fluorescence endomicroscopy with hybrid-illumination imaging through a flexible fiber bundle

NASA Astrophysics Data System (ADS)

Santos, Silvia; Chu, Kengyeh K.; Lim, Daryl; Bozinovic, Nenad; Ford, Tim N.; Hourtoule, Claire; Bartoo, Aaron C.; Singh, Satish K.; Mertz, Jerome

2009-05-01

We present an endomicroscope apparatus that exhibits out-of-focus background rejection based on wide-field illumination through a flexible imaging fiber bundle. Our technique, called HiLo microscopy, involves acquiring two images, one with grid-pattern illumination and another with standard uniform illumination. An evaluation of the image contrast with grid-pattern illumination provides an optically sectioned image with low resolution. This is complemented with high-resolution information from the uniform illumination image, leading to a full-resolution image that is optically sectioned. HiLo endomicroscope movies are presented of fluorescently labeled rat colonic mucosa.

Low-temperature field ion microscopy of carbon nanotubes

NASA Astrophysics Data System (ADS)

Ksenofontov, V. A.; Gurin, V. A.; Gurin, I. V.; Kolosenko, V. V.; Mikhailovskij, I. M.; Sadanov, E. V.; Mazilova, T. I.; Velikodnaya, O. A.

2007-10-01

The methods of high-resolution field ion microscopy with sample cooling to liquid helium temperature are used in a study of the products of gas-phase catalytic pyrolysis of hydrocarbons in the form of graphitized fibers containing carbon nanotubes. Full atomic resolution of the end cap of closed carbon nanotubes is achieved for the first time. It is found that the atomic structure of the tops of the caps of subnanometer carbon tubes consists predominantly of hexagonal rings. A possible reason for the improvement of the resolution of field ion images of nanotubes upon deep cooling is discussed.

Energy resolution improvement of CdTe detectors by using the principal component analysis technique

NASA Astrophysics Data System (ADS)

Alharbi, T.

2018-02-01

In this paper, we report on the application of the Principal Component Analysis (PCA) technique for the improvement of the γ-ray energy resolution of CdTe detectors. The PCA technique is used to estimate the amount of charge-trapping effect which is reflected in the shape of each detector pulse, thereby correcting for the charge-trapping effect. The details of the method are described and the results obtained with a CdTe detector are shown. We have achieved an energy resolution of 1.8 % (FWHM) at 662 keV with full detection efficiency from a 1 mm thick CdTe detector which gives an energy resolution of 4.5 % (FWHM) by using the standard pulse processing method.

An image quality comparison study between XVI and OBI CBCT systems.

PubMed

Kamath, Srijit; Song, William; Chvetsov, Alexei; Ozawa, Shuichi; Lu, Haibin; Samant, Sanjiv; Liu, Chihray; Li, Jonathan G; Palta, Jatinder R

2011-02-04

The purpose of this study is to evaluate and compare image quality characteristics for two commonly used and commercially available CBCT systems: the X-ray Volumetric Imager and the On-Board Imager. A commonly used CATPHAN image quality phantom was used to measure various image quality parameters, namely, pixel value stability and accuracy, noise, contrast to noise ratio (CNR), high-contrast resolution, low contrast resolution and image uniformity. For the XVI unit, we evaluated the image quality for four manufacturer-supplied protocols as a function of mAs. For the OBI unit, we did the same for the full-fan and half-fan scanning modes, which were respectively used with the full bow-tie and half bow-tie filters. For XVI, the mean pixel values of regions of interest were found to generally decrease with increasing mAs for all protocols, while they were relatively stable with mAs for OBI. Noise was slightly lower on XVI and was seen to decrease with increasing mAs, while CNR increased with mAs for both systems. For XVI and OBI, the high-contrast resolution was approximately limited by the pixel resolution of the reconstructed image. On OBI images, up to 6 and 5 discs of 1% and 0.5% contrast, respectively, were visible for a high mAs setting using the full-fan mode, while none of the discs were clearly visible on the XVI images for various mAs settings when the medium resolution reconstruction was used. In conclusion, image quality parameters for XVI and OBI have been quantified and compared for clinical protocols under various mAs settings. These results need to be viewed in the context of a recent study that reported the dose-mAs relationship for the two systems and found that OBI generally delivered higher imaging doses than XVI.

Early Spring Post-Fire Snow Albedo Dynamics in High Latitude Boreal Forests Using Landsat-8 OLI Data

NASA Technical Reports Server (NTRS)

Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Roman, Miguel O.

2016-01-01

Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (less than 100 m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high-burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500 m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems.

Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data

PubMed Central

Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Román, Miguel O.

2018-01-01

Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems. PMID:29769751

Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data.

PubMed

Wang, Zhuosen; Erb, Angela M; Schaaf, Crystal B; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A; Román, Miguel O

2016-11-01

Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems.

Estimating the resolution limit of the map equation in community detection

NASA Astrophysics Data System (ADS)

Kawamoto, Tatsuro; Rosvall, Martin

2015-01-01

A community detection algorithm is considered to have a resolution limit if the scale of the smallest modules that can be resolved depends on the size of the analyzed subnetwork. The resolution limit is known to prevent some community detection algorithms from accurately identifying the modular structure of a network. In fact, any global objective function for measuring the quality of a two-level assignment of nodes into modules must have some sort of resolution limit or an external resolution parameter. However, it is yet unknown how the resolution limit affects the so-called map equation, which is known to be an efficient objective function for community detection. We derive an analytical estimate and conclude that the resolution limit of the map equation is set by the total number of links between modules instead of the total number of links in the full network as for modularity. This mechanism makes the resolution limit much less restrictive for the map equation than for modularity; in practice, it is orders of magnitudes smaller. Furthermore, we argue that the effect of the resolution limit often results from shoehorning multilevel modular structures into two-level descriptions. As we show, the hierarchical map equation effectively eliminates the resolution limit for networks with nested multilevel modular structures.

High-voltage compatible, full-depleted CCD

DOEpatents

Holland, Stephen Edward

2007-09-18

A charge coupled device for detecting electromagnetic and particle radiation is described. The device includes a high-resistivity semiconductor substrate, buried channel regions, gate electrode circuitry, and amplifier circuitry. For good spatial resolution and high performance, especially when operated at high voltages with full or nearly full depletion of the substrate, the device can also include a guard ring positioned near channel regions, a biased channel stop, and a biased polysilicon electrode over the channel stop.

Projection x-space magnetic particle imaging.

PubMed

Goodwill, Patrick W; Konkle, Justin J; Zheng, Bo; Saritas, Emine U; Conolly, Steven M

2012-05-01

Projection magnetic particle imaging (MPI) can improve imaging speed by over 100-fold over traditional 3-D MPI. In this work, we derive the 2-D x-space signal equation, 2-D image equation, and introduce the concept of signal fading and resolution loss for a projection MPI imager. We then describe the design and construction of an x-space projection MPI scanner with a field gradient of 2.35 T/m across a 10 cm magnet free bore. The system has an expected resolution of 3.5 × 8.0 mm using Resovist tracer, and an experimental resolution of 3.8 × 8.4 mm resolution. The system images 2.5 cm × 5.0 cm partial field-of views (FOVs) at 10 frames/s, and acquires a full field-of-view of 10 cm × 5.0 cm in 4 s. We conclude by imaging a resolution phantom, a complex "Cal" phantom, mice injected with Resovist tracer, and experimentally confirm the theoretically predicted x-space spatial resolution.

Integral imaging with multiple image planes using a uniaxial crystal plate.

PubMed

Park, Jae-Hyeung; Jung, Sungyong; Choi, Heejin; Lee, Byoungho

2003-08-11

Integral imaging has been attracting much attention recently for its several advantages such as full parallax, continuous view-points, and real-time full-color operation. However, the thickness of the displayed three-dimensional image is limited to relatively small value due to the degradation of the image resolution. In this paper, we propose a method to provide observers with enhanced perception of the depth without severe resolution degradation by the use of the birefringence of a uniaxial crystal plate. The proposed integral imaging system can display images integrated around three central depth planes by dynamically altering the polarization and controlling both elemental images and dynamic slit array mask accordingly. We explain the principle of the proposed method and verify it experimentally.

In vivo high resolution human corneal imaging using full-field optical coherence tomography.

PubMed

Mazlin, Viacheslav; Xiao, Peng; Dalimier, Eugénie; Grieve, Kate; Irsch, Kristina; Sahel, José-Alain; Fink, Mathias; Boccara, A Claude

2018-02-01

We present the first full-field optical coherence tomography (FFOCT) device capable of in vivo imaging of the human cornea. We obtained images of the epithelial structures, Bowman's layer, sub-basal nerve plexus (SNP), anterior and posterior stromal keratocytes, stromal nerves, Descemet's membrane and endothelial cells with visible nuclei. Images were acquired with a high lateral resolution of 1.7 µm and relatively large field-of-view of 1.26 mm x 1.26 mm - a combination, which, to the best of our knowledge, has not been possible with other in vivo human eye imaging methods. The latter together with a contactless operation, make FFOCT a promising candidate for becoming a new tool in ophthalmic diagnostics.

High Resolution Numerical Simulations of Primary Atomization in Diesel Sprays with Single Component Reference Fuels

DTIC Science & Technology

2015-09-01

NC. 14. ABSTRACT A high-resolution numerical simulation of jet breakup and spray formation from a complex diesel fuel injector at diesel engine... diesel fuel injector at diesel engine type conditions has been performed. A full understanding of the primary atomization process in diesel fuel... diesel liquid sprays the complexity is further compounded by the physical attributes present including nozzle turbulence, large density ratios

A resolution deploring the violent repression of peaceful demonstrators in Venezuela, calling for full accountability for human rights violations taking place in Venezuela, and supporting the right of the Venezuelan people to the free and peaceful exercise of representative democracy.

THOMAS, 113th Congress

Sen. Menendez, Robert [D-NJ

2014-02-27

Senate - 03/12/2014 Resolution agreed to in Senate without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

Cosmological parameters from a re-analysis of the WMAP 7 year low-resolution maps

NASA Astrophysics Data System (ADS)

Finelli, F.; De Rosa, A.; Gruppuso, A.; Paoletti, D.

2013-06-01

Cosmological parameters from Wilkinson Microwave Anisotropy Probe (WMAP) 7 year data are re-analysed by substituting a pixel-based likelihood estimator to the one delivered publicly by the WMAP team. Our pixel-based estimator handles exactly intensity and polarization in a joint manner, allowing us to use low-resolution maps and noise covariance matrices in T, Q, U at the same resolution, which in this work is 3.6°. We describe the features and the performances of the code implementing our pixel-based likelihood estimator. We perform a battery of tests on the application of our pixel-based likelihood routine to WMAP publicly available low-resolution foreground-cleaned products, in combination with the WMAP high-ℓ likelihood, reporting the differences on cosmological parameters evaluated by the full WMAP likelihood public package. The differences are not only due to the treatment of polarization, but also to the marginalization over monopole and dipole uncertainties present in the WMAP pixel likelihood code for temperature. The credible central value for the cosmological parameters change below the 1σ level with respect to the evaluation by the full WMAP 7 year likelihood code, with the largest difference in a shift to smaller values of the scalar spectral index nS.

High resolution in-vivo imaging of skin with full field optical coherence tomography

NASA Astrophysics Data System (ADS)

Dalimier, E.; Bruhat, Alexis; Grieve, K.; Harms, F.; Martins, F.; Boccara, C.

2014-03-01

Full-field OCT (FFOCT) has the ability to provide en-face images with a very good axial sectioning as well as a very high transverse resolution (about 1 microns in all directions). Therefore it offers the possibility to visualize biological tissues with very high resolution both on the axial native view, and on vertical reconstructed sections. Here we investigated the potential dermatological applications of in-vivo skin imaging with FFOCT. A commercial FFOCT device was adapted for the in-vivo acquisition of stacks of images on the arm, hand and finger. Several subjects of different benign and pathological skin conditions were tested. The images allowed measurement of the stratum corneum and epidermis thicknesses, measurement of the stratum corneum refractive index, size measurement and count of the keratinocytes, visualization of the dermal-epidermal junction, and visualization of the melanin granules and of the melanocytes. Skins with different pigmentations could be discriminated and skin pathologies such as eczema could be identified. The very high resolution offered by FFOCT both on axial native images and vertical reconstructed sections allows for the visualization and measurement of a set of parameters useful for cosmetology and dermatology. In particular, FFOCT is a potential tool for the understanding and monitoring of skin hydration and pigmentation, as well as skin inflammation.

Definition of the Spatial Resolution of X-Ray Microanalysis in Thin Foils

NASA Technical Reports Server (NTRS)

Williams, D. B.; Michael, J. R.; Goldstein, J. I.; Romig, A. D., Jr.

1992-01-01

The spatial resolution of X-ray microanalysis in thin foils is defined in terms of the incident electron beam diameter and the average beam broadening. The beam diameter is defined as the full width tenth maximum of a Gaussian intensity distribution. The spatial resolution is calculated by a convolution of the beam diameter and the average beam broadening. This definition of the spatial resolution can be related simply to experimental measurements of composition profiles across interphase interfaces. Monte Carlo calculations using a high-speed parallel supercomputer show good agreement with this definition of the spatial resolution and calculations based on this definition. The agreement is good over a range of specimen thicknesses and atomic number, but is poor when excessive beam tailing distorts the assumed Gaussian electron intensity distributions. Beam tailing occurs in low-Z materials because of fast secondary electrons and in high-Z materials because of plural scattering.

Spotlight-Mode Synthetic Aperture Radar Processing for High-Resolution Lunar Mapping

NASA Technical Reports Server (NTRS)

Harcke, Leif; Weintraub, Lawrence; Yun, Sang-Ho; Dickinson, Richard; Gurrola, Eric; Hensley, Scott; Marechal, Nicholas

2010-01-01

During the 2008-2009 year, the Goldstone Solar System Radar was upgraded to support radar mapping of the lunar poles at 4 m resolution. The finer resolution of the new system and the accompanying migration through resolution cells called for spotlight, rather than delay-Doppler, imaging techniques. A new pre-processing system supports fast-time Doppler removal and motion compensation to a point. Two spotlight imaging techniques which compensate for phase errors due to i) out of focus-plane motion of the radar and ii) local topography, have been implemented and tested. One is based on the polar format algorithm followed by a unique autofocus technique, the other is a full bistatic time-domain backprojection technique. The processing system yields imagery of the specified resolution. Products enabled by this new system include topographic mapping through radar interferometry, and change detection techniques (amplitude and coherent change) for geolocation of the NASA LCROSS mission impact site.

Improving spatial and spectral resolution of TCV Thomson scattering

NASA Astrophysics Data System (ADS)

Hawke, J.; Andrebe, Y.; Bertizzolo, R.; Blanchard, P.; Chavan, R.; Decker, J.; Duval, B.; Lavanchy, P.; Llobet, X.; Marlétaz, B.; Marmillod, P.; Pochon, G.; Toussaint, M.

2017-12-01

The recently completed MST2 upgrade to the Thomson scattering (TS) system on TCV (Tokamak à Configuration Variable) at the Swiss Plasma Center aims to provide an enhanced spatial and spectral resolution while maintaining the high level of diagnostic flexibility for the study of TCV plasmas. The MST2 (Medium Sized Tokamak) is a work program within the Eurofusion ITER physics department, aimed at exploiting Europe's medium sized tokamak programs for a better understanding of ITER physics. This upgrade to the TCV Thomson scattering system involved the installation of 40 new compact 5-channel spectrometers and modifications to the diagnostics fiber optic design. The complete redesign of the fiber optic backplane incorporates fewer larger diameter fibers, allowing for a higher resolution in both the core and edge of TCV plasmas along the laser line, with a slight decrease in the signal to noise ratio of Thomson measurements. The 40 new spectrometers added to the system are designed to cover the full range of temperatures expected in TCV, able to measure electron temperatures (Te) with high precision between (6 eV and 20 keV) . The design of these compact spectrometers stems originally from the design utilized in the MAST (Mega Amp Spherical Tokamak) TS system located in Oxfordshire, United Kingdom. This design was implemented on TCV with an overall layout of optical fibers and spectrometers to achieve an overall increase in the spatial resolution, specifically a resolution of approximately 1% of the minor radius within the plasma pedestal region. These spectrometers also enhance the diagnostic spectral resolution, especially within the plasma edge, due to the low Te measurement capabilities. These additional spectrometers allow for a much greater diagnostic flexibility, allowing for quality full Thomson profiles in 75% of TCV plasma configurations.

The Effect of Magnetic Field on Positron Range and Spatial Resolution in an Integrated Whole-Body Time-Of-Flight PET/MRI System.

PubMed

Huang, Shih-Ying; Savic, Dragana; Yang, Jaewon; Shrestha, Uttam; Seo, Youngho

2014-11-01

Simultaneous imaging systems combining positron emission tomography (PET) and magnetic resonance imaging (MRI) have been actively investigated. A PET/MR imaging system (GE Healthcare) comprised of a time-of-flight (TOF) PET system utilizing silicon photomultipliers (SiPMs) and 3-tesla (3T) MRI was recently installed at our institution. The small-ring (60 cm diameter) TOF PET subsystem of this PET/MRI system can generate images with higher spatial resolution compared with conventional PET systems. We have examined theoretically and experimentally the effect of uniform magnetic fields on the spatial resolution for high-energy positron emitters. Positron emitters including 18 F, 124 I, and 68 Ga were simulated in water using the Geant4 Monte Carlo toolkit in the presence of a uniform magnetic field (0, 3, and 7 Tesla). The positron annihilation position was tracked to determine the 3D spatial distribution of the 511-keV gammy ray emission. The full-width at tenth maximum (FWTM) of the positron point spread function (PSF) was determined. Experimentally, 18 F and 68 Ga line source phantoms in air and water were imaged with an investigational PET/MRI system and a PET/CT system to investigate the effect of magnetic field on the spatial resolution of PET. The full-width half maximum (FWHM) of the line spread function (LSF) from the line source was determined as the system spatial resolution. Simulations and experimental results show that the in-plane spatial resolution was slightly improved at field strength as low as 3 Tesla, especially when resolving signal from high-energy positron emitters in the air-tissue boundary.

S-NPP CrIS Full Resolution Sensor Data Record Processing and Evaluations

NASA Astrophysics Data System (ADS)

Chen, Y.; Han, Y.; Wang, L.; Tremblay, D. A.; Jin, X.; Weng, F.

2014-12-01

The Cross-track Infrared Sounder (CrIS) on Suomi National Polar-orbiting Partnership Satellite (S-NPP) is a Fourier transform spectrometer. It provides a total of 1305 channels in the normal mode for sounding the atmosphere. CrIS can also be operated in the full spectral resolution (FSR) mode, in which the MWIR and SWIR band interferograms are recorded with the same maximum path difference as the LWIR band and with spectral resolution of 0.625 cm-1 for all three bands (total 2211 channels). NOAA will operate CrIS in FSR mode in December 2014 and the Joint Polar Satellite System (JPSS). Up to date, the FSR mode has been commanded three times in-orbit (02/23/2012, 03/12/2013, and 08/27/2013). Based on CrIS Algorithm Development Library (ADL), CrIS full resolution Processing System (CRPS) has developed to generate the FSR Sensor Data Record (SDR). This code can also be run for normal mode and truncation mode SDRs with recompiling. Different calibration approaches are implemented in the code in order to study the ringing effect observed in CrIS normal mode SDR and to support to select the best calibration algorithm for J1. We develop the CrIS FSR SDR Validation System to quantify the CrIS radiometric and spectral accuracy, since they are crucial for improving its data assimilation in the numerical weather prediction, and for retrieving atmospheric trace gases. In this study, CrIS full resolution SDRs are generated from CRPS using the data collected from FSR mode of S-NPP, and the radiometric and spectral accuracy are assessed by using the Community Radiative Transfer Model (CRTM) and European Centre for Medium-Range Weather Forecasts (ECMWF) forecast fields. The biases between observation and simulations are evaluated to estimate the FOV-2-FOV variability and bias under clear sky over ocean. Double difference method and Simultaneous Nadir Overpass (SNO) method are also used to assess the CrIS radiance consistency with well-validated IASI. Two basic frequency validation methods (absolute and relative spectral validations) are used to assess the CrIS spectral accuracy. Results show that CrIS SDRs from FSR have similar radiometric and spectral accuracy as those from normal mode.

Uncertainty Estimation in Elastic Full Waveform Inversion by Utilising the Hessian Matrix

NASA Astrophysics Data System (ADS)

Hagen, V. S.; Arntsen, B.; Raknes, E. B.

2017-12-01

Elastic Full Waveform Inversion (EFWI) is a computationally intensive iterative method for estimating elastic model parameters. A key element of EFWI is the numerical solution of the elastic wave equation which lies as a foundation to quantify the mismatch between synthetic (modelled) and true (real) measured seismic data. The misfit between the modelled and true receiver data is used to update the parameter model to yield a better fit between the modelled and true receiver signal. A common approach to the EFWI model update problem is to use a conjugate gradient search method. In this approach the resolution and cross-coupling for the estimated parameter update can be found by computing the full Hessian matrix. Resolution of the estimated model parameters depend on the chosen parametrisation, acquisition geometry, and temporal frequency range. Although some understanding has been gained, it is still not clear which elastic parameters can be reliably estimated under which conditions. With few exceptions, previous analyses have been based on arguments using radiation pattern analysis. We use the known adjoint-state technique with an expansion to compute the Hessian acting on a model perturbation to conduct our study. The Hessian is used to infer parameter resolution and cross-coupling for different selections of models, acquisition geometries, and data types, including streamer and ocean bottom seismic recordings. Information about the model uncertainty is obtained from the exact Hessian, and is essential when evaluating the quality of estimated parameters due to the strong influence of source-receiver geometry and frequency content. Investigation is done on both a homogeneous model and the Gullfaks model where we illustrate the influence of offset on parameter resolution and cross-coupling as a way of estimating uncertainty.

Non-contact full-field optical coherence tomography: a novel tool for in vivo imaging of the human cornea (Conference Presentation)

NASA Astrophysics Data System (ADS)

Mazlin, Viacheslav; Dalimier, Eugénie; Grieve, Katharine F.; Irsch, Kristina; Sahel, José-Alain; Fink, Mathias; Boccara, A. Claude

2017-02-01

According to the World Health Organization (WHO), corneal diseases alongside with cataract and retinal diseases are major causes of blindness worldwide. For the 95.5% of corneal blindness cases, prevention or rehabilitation could have been possible without negative consequences for vision, provided that disease is diagnosed early. However, diagnostics at the early stage requires cellular-level resolution, which is not achieved with routinely used Slit-lamp and OCT instruments. Confocal microscopy allows examination of the cornea at a resolution approaching histological detail, however requires contact with a patient's eye. The recently developed full-field OCT technique, in which 2D en face tangential optical slices are directly recorded on a camera, was successfully applied for ex vivo eye imaging. However, in vivo human eye imaging has not been demonstrated yet. Here we present a novel non-contact full-field OCT system, which is capable of imaging in air and, therefore, shows potential for in vivo cornea imaging in patients. The first cellular-level resolution ex vivo images of cornea, obtained in a completely non-contact way, were demonstrated. We were able to scan through the entire cornea (400 µm) and resolve epithelium, Bowman's layer, stroma and endothelium. FFOCT images of the human cornea in vivo were obtained for the first time. The epithelium structures and stromal keratocyte cells were distinguishable. Both ex vivo and in vivo images were acquired with a large (1.26 mm x 1.26 mm) field of view. Cellular details in obtained images make this device a promising candidate for realization of high-resolution in vivo cornea imaging.

Optimization of the spatial resolution for the GE discovery PET/CT 710 by using NEMA NU 2-2007 standards

NASA Astrophysics Data System (ADS)

Yoon, Hyun Jin; Jeong, Young Jin; Son, Hye Joo; Kang, Do-Young; Hyun, Kyung-Yae; Lee, Min-Kyung

2015-01-01

The spatial resolution in positron emission tomography (PET) is fundamentally limited by the geometry of the detector element, the positron's recombination range with electrons, the acollinearity of the positron, the crystal decoding error, the penetration into the detector ring, and the reconstruction algorithms. In this paper, optimized parameters are suggested to produce high-resolution PET images by using an iterative reconstruction algorithm. A phantom with three point sources structured with three capillary tubes was prepared with an axial extension of less than 1 mm and was filled with 18F-fluorodeoxyglucose (18F-FDG) with concentrations above 200 MBq/cc. The performance measures of all the PET images were acquired according to the National Electrical Manufacturers Association (NEMA) NU 2-2007 standards procedures. The parameters for the iterative reconstruction were adjusted around the values recommended by General Electric GE, and the optimized values of the spatial resolution and the full width at half maximum (FWHM) or the full width at tenth of maximum (FWTM) values were found for the best PET resolution. The axial and the transverse spatial resolutions, according to the filtered back-projection (FBP) at 1 cm off-axis, were 4.81 and 4.48 mm, respectively. The axial and the transaxial spatial resolutions at 10 cm off-axis were 5.63 mm and 5.08 mm, respectively, and the trans-axial resolution at 10 cm was evaluated as the average of the radial and the tangential measurements. The recommended optimized parameters of the spatial resolution according to the NEMA phantom for the number of subsets, the number of iterations, and the Gaussian post-filter are 12, 3, and 3 mm for the iterative reconstruction VUE Point HD without the SharpIR algorithm (HD), and 12, 12, and 5.2 mm with SharpIR (HD.S), respectively, according to the Advantage Workstation Volume Share 5 (AW4.6). The performance measurements for the GE Discovery PET/CT 710 using the NEMA NU 2-2007 standards from our results will be helpful in the quantitative analysis of PET scanner images. The spatial resolution was modified more by using an improved algorithm such as HD.S, than by using HD and FBP. The use of the optimized parameters for iterative reconstructions is strongly recommended for qualitative images from the GE Discovery PET/CT 710 scanner.

Light-sheet enhanced resolution of light field microscopy for rapid imaging of large volumes

NASA Astrophysics Data System (ADS)

Madrid Wolff, Jorge; Castro, Diego; Arbeláez, Pablo; Forero-Shelton, Manu

2018-02-01

Whole-brain imaging is challenging because it demands microscopes with high temporal and spatial resolution, which are often at odds, especially in the context of large fields of view. We have designed and built a light-sheet microscope with digital micromirror illumination and light-field detection. On the one hand, light sheets provide high resolution optical sectioning on live samples without compromising their viability. On the other hand, light field imaging makes it possible to reconstruct full volumes of relatively large fields of view from a single camera exposure; however, its enhanced temporal resolution comes at the expense of spatial resolution, limiting its applicability. We present an approach to increase the resolution of light field images using DMD-based light sheet illumination. To that end, we develop a method to produce synthetic resolution targets for light field microscopy and a procedure to correct the depth at which planes are refocused with rendering software. We measured the axial resolution as a function of depth and show a three-fold potential improvement with structured illumination, albeit by sacrificing some temporal resolution, also three-fold. This results in an imaging system that may be adjusted to specific needs without having to reassemble and realign it. This approach could be used to image relatively large samples at high rates.

Ensuring Safety of Navigation: A Three-Tiered Approach

NASA Astrophysics Data System (ADS)

Johnson, S. D.; Thompson, M.; Brazier, D.

2014-12-01

The primary responsibility of the Hydrographic Department at the Naval Oceanographic Office (NAVOCEANO) is to support US Navy surface and sub-surface Safety of Navigation (SoN) requirements. These requirements are interpreted, surveys are conducted, and accurate products are compiled and archived for future exploitation. For a number of years NAVOCEANO has employed a two-tiered data-basing structure to support SoN. The first tier (Data Warehouse, or DWH) provides access to the full-resolution sonar and lidar data. DWH preserves the original data such that any scale product can be built. The second tier (Digital Bathymetric Database - Variable resolution, or DBDB-V) served as the final archive for SoN chart scale, gridded products compiled from source bathymetry. DBDB-V has been incorporated into numerous DoD tactical decision aids and serves as the foundation bathymetry for ocean modeling. With the evolution of higher density survey systems and the addition of high-resolution gridded bathymetry product requirements, a two-tiered model did not provide an efficient solution for SoN. The two-tiered approach required scientists to exploit full-resolution data in order to build any higher resolution product. A new perspective on the archival and exploitation of source data was required. This new perspective has taken the form of a third tier, the Navigation Surface Database (NSDB). NSDB is an SQLite relational database populated with International Hydrographic Organization (IHO), S-102 compliant Bathymetric Attributed Grids (BAGs). BAGs archived within NSDB are developed at the highest resolution that the collection sensor system can support and contain nodal estimates for depth, uncertainty, separation values and metadata. Gridded surface analysis efforts culminate in the generation of the source resolution BAG files and their storage within NSDB. Exploitation of these resources eliminates the time and effort needed to re-grid and re-analyze native source file formats.

In situ X-ray-based imaging of nano materials

DOE PAGES

Weker, Johanna Nelson; Huang, Xiaojing; Toney, Michael F.

2016-02-13

We study functional nanomaterials that are heterogeneous and understanding their behavior during synthesis and operation requires high resolution diagnostic imaging tools that can be used in situ. Over the past decade, huge progress has been made in the development of X-ray based imaging, including full field and scanning microscopy and their analogs in coherent diffractive imaging. Currently, spatial resolution of about 10 nm and time resolution of sub-seconds are achievable. For catalysis, X-ray imaging allows tracking of particle chemistry under reaction conditions. In energy storage, in situ X-ray imaging of electrode particles is providing important insight into degradation processes. Recently,more » both spatial and temporal resolutions are improving to a few nm and milliseconds and these developments will open up unprecedented opportunities.« less

A Segmented Neutron Detector with a High Position Resolution for the (p,pn) Reactions

NASA Astrophysics Data System (ADS)

Kubota, Yuki; Sasano, Masaki; Uesaka, Tomohiro; Dozono, Masanori; Itoh, Masatoshi; Kawase, Shoichiro; Kobayashi, Motoki; Lee, CheongSoo; Matsubara, Hiroaki; Miki, Kenjiro; Miya, Hiroyuki; Ota, Shinsuke; Sekiguchi, Kimiko; Shima, Tatsushi; Taguchi, Takahiro; Tamii, Atsushi; Tang, Tsz Leung; Tokieda, Hiroshi; Wakasa, Tomotsugu; Wakui, Takashi; Yasuda, Jumpei; Zenihiro, Juzo

We are developing a neutron detector with a high position resolution to study the single particle properties of nuclei by the knockout (p,pn) reaction at intermediate energies. We constructed a prototype detector consisting of plastic scintillating fibers and multi-anode photomultiplier tubes (PMTs). Test experiments using 200- and 70-MeV proton and 199-, 188-, 68-, and 50-MeV neutron were performed for characterizing its performance. Preliminary results show that a position resolution of about 3 mm at full-width at half-maximum (FWHM) is realized as designed. The resulting separation-energy resolution to be obtained for (p,pn) measurement would be 1 MeV in FWHM, when the detector is used at a distance of 2 m from the target for measuring the neutron momentum.

Overlapped Fourier coding for optical aberration removal

PubMed Central

Horstmeyer, Roarke; Ou, Xiaoze; Chung, Jaebum; Zheng, Guoan; Yang, Changhuei

2014-01-01

We present an imaging procedure that simultaneously optimizes a camera’s resolution and retrieves a sample’s phase over a sequence of snapshots. The technique, termed overlapped Fourier coding (OFC), first digitally pans a small aperture across a camera’s pupil plane with a spatial light modulator. At each aperture location, a unique image is acquired. The OFC algorithm then fuses these low-resolution images into a full-resolution estimate of the complex optical field incident upon the detector. Simultaneously, the algorithm utilizes redundancies within the acquired dataset to computationally estimate and remove unknown optical aberrations and system misalignments via simulated annealing. The result is an imaging system that can computationally overcome its optical imperfections to offer enhanced resolution, at the expense of taking multiple snapshots over time. PMID:25321982

Imaging of transient surface acoustic waves by full-field photorefractive interferometry.

PubMed

Xiong, Jichuan; Xu, Xiaodong; Glorieux, Christ; Matsuda, Osamu; Cheng, Liping

2015-05-01

A stroboscopic full-field imaging technique based on photorefractive interferometry for the visualization of rapidly changing surface displacement fields by using of a standard charge-coupled device (CCD) camera is presented. The photorefractive buildup of the space charge field during and after probe laser pulses is simulated numerically. The resulting anisotropic diffraction upon the refractive index grating and the interference between the polarization-rotated diffracted reference beam and the transmitted signal beam are modeled theoretically. The method is experimentally demonstrated by full-field imaging of the propagation of photoacoustically generated surface acoustic waves with a temporal resolution of nanoseconds. The surface acoustic wave propagation in a 23 mm × 17 mm area on an aluminum plate was visualized with 520 × 696 pixels of the CCD sensor, yielding a spatial resolution of 33 μm. The short pulse duration (8 ns) of the probe laser yields the capability of imaging SAWs with frequencies up to 60 MHz.

Anti-Stokes effect CCD camera and SLD based optical coherence tomography for full-field imaging in the 1550nm region

NASA Astrophysics Data System (ADS)

Kredzinski, Lukasz; Connelly, Michael J.

2012-06-01

Full-field Optical coherence tomography is an en-face interferometric imaging technology capable of carrying out high resolution cross-sectional imaging of the internal microstructure of an examined specimen in a non-invasive manner. The presented system is based on competitively priced optical components available at the main optical communications band located in the 1550 nm region. It consists of a superluminescent diode and an anti-stokes imaging device. The single mode fibre coupled SLD was connected to a multi-mode fibre inserted into a mode scrambler to obtain spatially incoherent illumination, suitable for OCT wide-field modality in terms of crosstalk suppression and image enhancement. This relatively inexpensive system with moderate resolution of approximately 24um x 12um (axial x lateral) was constructed to perform a 3D cross sectional imaging of a human tooth. To our knowledge this is the first 1550 nm full-field OCT system reported.

High-frame-rate full-vocal-tract 3D dynamic speech imaging.

PubMed

Fu, Maojing; Barlaz, Marissa S; Holtrop, Joseph L; Perry, Jamie L; Kuehn, David P; Shosted, Ryan K; Liang, Zhi-Pei; Sutton, Bradley P

2017-04-01

To achieve high temporal frame rate, high spatial resolution and full-vocal-tract coverage for three-dimensional dynamic speech MRI by using low-rank modeling and sparse sampling. Three-dimensional dynamic speech MRI is enabled by integrating a novel data acquisition strategy and an image reconstruction method with the partial separability model: (a) a self-navigated sparse sampling strategy that accelerates data acquisition by collecting high-nominal-frame-rate cone navigator sand imaging data within a single repetition time, and (b) are construction method that recovers high-quality speech dynamics from sparse (k,t)-space data by enforcing joint low-rank and spatiotemporal total variation constraints. The proposed method has been evaluated through in vivo experiments. A nominal temporal frame rate of 166 frames per second (defined based on a repetition time of 5.99 ms) was achieved for an imaging volume covering the entire vocal tract with a spatial resolution of 2.2 × 2.2 × 5.0 mm 3 . Practical utility of the proposed method was demonstrated via both validation experiments and a phonetics investigation. Three-dimensional dynamic speech imaging is possible with full-vocal-tract coverage, high spatial resolution and high nominal frame rate to provide dynamic speech data useful for phonetic studies. Magn Reson Med 77:1619-1629, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Interactively Browsing NASA's EOS Imagery in Full Resolution

NASA Astrophysics Data System (ADS)

Boller, R. A.; Joshi, T.; Schmaltz, J. E.; Ilavajhala, S.; Davies, D.; Murphy, K. J.

2012-12-01

Worldview is a new tool designed to interactively browse full-resolution imagery from NASA's fleet of Earth Observing System (EOS) satellites. It is web-based and developed using open standards (JavaScript, CSS, HTML) for cross-platform compatibility. It addresses growing user demands for access to full-resolution imagery by providing a responsive, interactive interface with global coverage, no artificial boundaries, and views in geographic and polar projections. Currently tailored to the near real-time community, Worldview enables the rapid evaluation and comparison of imagery related to such application areas as fires, floods, and air quality. It is supported by the Global Imagery Browse Services (GIBS), a system that continuously ingests, mosaics, and serves approximately 21GB of imagery daily. This imagery spans over 50 data products that are available within three hours of observation from instruments aboard Terra, Aqua, and Aura. The GIBS image archive began in May 2012 and will have published approximately 4.4TB of imagery as of December 2012. Worldview facilitates rapid access to this archive and is supplemented by socioeconomic data layers from the Socioeconomic Data and Applications Center (SEDAC), including products such as population density and economic risk from cyclones. Future plans include the accessibility of additional products that cover the entire Terra/MODIS and Aqua/MODIS missions (>150TB) and the ability to download the underlying science data of the onscreen imagery.

Rat brain imaging using full field optical coherence microscopy with short multimode fiber probe

NASA Astrophysics Data System (ADS)

Sato, Manabu; Saito, Daisuke; Kurotani, Reiko; Abe, Hiroyuki; Kawauchi, Satoko; Sato, Shunichi; Nishidate, Izumi

2017-02-01

We demonstrated FF OCM(full field optical coherence microscopy) using an ultrathin forward-imaging SMMF (short multimode fiber) probe of 50 μm core diameter, 125 μm diameter, and 7.4 mm length, which is a typical graded-index multimode fiber for optical communications. The axial resolution was measured to be 2.20 μm, which is close to the calculated axial resolution of 2.06 μm. The lateral resolution was evaluated to be 4.38 μm using a test pattern. Assuming that the FWHM of the contrast is the DOF (depth of focus), the DOF of the signal is obtained at 36 μm and that of the OCM is 66 μm. The contrast of the OCT images was 6.1 times higher than that of the signal images due to the coherence gate. After an euthanasia the rat brain was resected and cut at 2.6mm tail from Bregma. Contacting SMMF to the primary somatosensory cortex and the agranular insular cortex of ex vivo brain, OCM images of the brain were measured 100 times with 2μm step. 3D OCM images of the brain were measured, and internal structure information was obtained. The feasibility of an SMMF as an ultrathin forward-imaging probe in full-field OCM has been demonstrated.

CO tip functionalization in subatomic resolution atomic force microscopy

NASA Astrophysics Data System (ADS)

Kim, Minjung; Chelikowsky, James R.

2015-10-01

Noncontact atomic force microscopy (nc-AFM) employing a CO-functionalized tip displays dramatically enhanced resolution wherein covalent bonds of polycyclic aromatic hydrocarbon can be imaged. Employing real-space pseudopotential first-principles calculations, we examine the role of CO in functionalizing the nc-AFM tip. Our calculations allow us to simulate full AFM images and ascertain the enhancement mechanism of the CO molecule. We consider two approaches: one with an explicit inclusion of the CO molecule and one without. By comparing our simulations to existing experimental images, we ascribe the enhanced resolution of the CO functionalized tip to the special orbital characteristics of the CO molecule.

CO tip functionalization in subatomic resolution atomic force microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Minjung; Chelikowsky, James R.

2015-10-19

Noncontact atomic force microscopy (nc-AFM) employing a CO-functionalized tip displays dramatically enhanced resolution wherein covalent bonds of polycyclic aromatic hydrocarbon can be imaged. Employing real-space pseudopotential first-principles calculations, we examine the role of CO in functionalizing the nc-AFM tip. Our calculations allow us to simulate full AFM images and ascertain the enhancement mechanism of the CO molecule. We consider two approaches: one with an explicit inclusion of the CO molecule and one without. By comparing our simulations to existing experimental images, we ascribe the enhanced resolution of the CO functionalized tip to the special orbital characteristics of the CO molecule.

High-resolution extraction of particle size via Fourier Ptychography

NASA Astrophysics Data System (ADS)

Li, Shengfu; Zhao, Yu; Chen, Guanghua; Luo, Zhenxiong; Ye, Yan

2017-11-01

This paper proposes a method which can extract the particle size information with a resolution beyond λ/NA. This is achieved by applying Fourier Ptychographic (FP) ideas to the present problem. In a typical FP imaging platform, a 2D LED array is used as light sources for angle-varied illuminations, a series of low-resolution images was taken by a full sequential scan of the array of LEDs. Here, we demonstrate the particle size information is extracted by turning on each single LED on a circle. The simulated results show that the proposed method can reduce the total number of images, without loss of reliability in the results.

Development of SMAP Mission Cal/Val Activities

NASA Technical Reports Server (NTRS)

Colliander, A.; Jackson, T.; Kimball, J.; Cosh, M.; Spencer, M.; Entekhabi, D.; Njoku, E.; ONeill, P.

2010-01-01

The Soil Moisture Active Passive (SMAP) mission is a NASA directed mission to map global land surface soil moisture and freeze-thaw state. Instrument and mission details are shown. The key SMAP soil moisture product is provided at 10 km resolution with 0.04cubic cm/cubic cm accuracy. The freeze/thaw product is provided at 3 km resolution and 80% frozen-thawed classification accuracy. The full list of SMAP data products is shown.

A resolution recognizing the importance and sustainability of the United States hardwoods industry and urging that United States hardwoods and the products derived from United States hardwoods be given full consideration in any program to promote construction of environmentally preferable commercial, public, or private buildings.

THOMAS, 111th Congress

Sen. Lincoln, Blanche L. [D-AR

2010-02-09

Senate - 08/05/2010 Resolution agreed to in Senate without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

The Classification of Tongue Colors with Standardized Acquisition and ICC Profile Correction in Traditional Chinese Medicine

PubMed Central

Tu, Li-ping; Chen, Jing-bo; Hu, Xiao-juan; Zhang, Zhi-feng

2016-01-01

Background and Goal. The application of digital image processing techniques and machine learning methods in tongue image classification in Traditional Chinese Medicine (TCM) has been widely studied nowadays. However, it is difficult for the outcomes to generalize because of lack of color reproducibility and image standardization. Our study aims at the exploration of tongue colors classification with a standardized tongue image acquisition process and color correction. Methods. Three traditional Chinese medical experts are chosen to identify the selected tongue pictures taken by the TDA-1 tongue imaging device in TIFF format through ICC profile correction. Then we compare the mean value of L * a * b * of different tongue colors and evaluate the effect of the tongue color classification by machine learning methods. Results. The L * a * b * values of the five tongue colors are statistically different. Random forest method has a better performance than SVM in classification. SMOTE algorithm can increase classification accuracy by solving the imbalance of the varied color samples. Conclusions. At the premise of standardized tongue acquisition and color reproduction, preliminary objectification of tongue color classification in Traditional Chinese Medicine (TCM) is feasible. PMID:28050555

Shuttle Systems 3-D Applications: Application of 3-D Graphics in Engineering Training for Shuttle Ground Processing

NASA Technical Reports Server (NTRS)

Godfrey, Gary S.

2003-01-01

This project illustrates an animation of the orbiter mate to the external tank, an animation of the OMS POD installation to the orbiter, and a simulation of the landing gear mechanism at the Kennedy Space Center. A detailed storyboard was created to reflect each animation or simulation. Solid models were collected and translated into Pro/Engineer's prt and asm formats. These solid models included computer files of the: orbiter, external tank, solid rocket booster, mobile launch platform, transporter, vehicle assembly building, OMS POD fixture, and landing gear. A depository of the above solid models was established. These solid models were translated into several formats. This depository contained the following files: stl for sterolithography, stp for neutral file work, shrinkwrap for compression, tiff for photoshop work, jpeg for Internet use, and prt and asm for Pro/Engineer use. Solid models were created of the material handling sling, bay 3 platforms, and orbiter contact points. Animations were developed using mechanisms to reflect each storyboard. Every effort was made to build all models technically correct for engineering use. The result was an animated routine that could be used by NASA for training material handlers and uncovering engineering safety issues.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillion, D.

This code enables one to display, take line-outs on, and perform various transformations on an image created by an array of integer*2 data. Uncompressed eight-bit TIFF files created on either the Macintosh or the IBM PC may also be read in and converted to a 16 bit signed integer image. This code is designed to handle all the formats used for PDS (photo-densitometer) files at the Lawrence Livermore National Laboratory. These formats are all explained by the application code. The image may be zoomed infinitely and the gray scale mapping can be easily changed. Line-outs may be horizontal or verticalmore » with arbitrary width, angled with arbitrary end points, or taken along any path. This code is usually used to examine spectrograph data. Spectral lines may be identified and a polynomial fit from position to wavelength may be found. The image array can be remapped so that the pixels all have the same change of lambda width. It is not necessary to do this, however. Lineouts may be printed, saved as Cricket tab-delimited files, or saved as PICT2 files. The plots may be linear, semilog, or logarithmic with nice values and proper scientific notation. Typically, spectral lines are curved.« less

Improving Access to Precipitation Data for GIS Users: Designing for Ease of Use

NASA Technical Reports Server (NTRS)

Stocker, Erich F.; Kelley, Owen A.

2007-01-01

The Global Precipitation Measurement Mission (GPM) is a NASA/JAXA led international mission to configure a constellation of space-based radiometers to monitor precipitation over the globe. The GPM goal of making global 3-hour precipitation products available in near real-time will make such global products more useful to a broader community of modelers and Geographic Information Systems (GIS) users than is currently the case with remote sensed precipitation products. Based on the existing interest to make Tropical Rainfall Measuring Mission (TRMM) data available to a growing community of GIS users as well as what will certainly be an expanded community during the GPM era, it is clear that data systems must make a greater effort to provide data in formats easily used by GIS. We describe precipitation GIS products being developed for TRMM data. These products will serve as prototypes for production efforts during the GPM era. We describe efforts to convert TRMM precipitation data to GeoTIFF, Shapefile, and ASCII grid. Clearly, our goal is to format GPM data so that it can be easily used within GIS applications. We desire feedback on these efforts and any additions or direction changes that should be undertaken by the data system.

Talk with Tiff: teen's inquiries to a sexual health website.

PubMed

Buzi, Ruth S; Smith, Peggy B; Barrera, Cristina

2015-01-01

Because of its availability, anonymity, and low cost of access, the Internet is an increasingly common way for adolescents to find information about sensitive issues. Sexual health website question portals are an important way for adolescents to seek personalized information tailored to their individualized needs. Few studies have examined the content within anonymous e-mails sent to these question portals. The purpose of this qualitative evaluation was to analyze thematic content of anonymous e-mails sent through a question portal on a comprehensive sexual health clinic website for an adolescent family planning clinic in a large city in the southwest United States. Between August 2009 and June 2012, the e-mail server received questions from 484 individuals who were seeking sexual health-related information. The authors used a content analysis to identify recurrent themes in the questions submitted. The most common questions regarded the cost of the clinic's services and testing for sexually transmitted diseases. The questions revealed that adolescents lack basic sexual health knowledge and hold many misconceptions. The findings support the usefulness of online question portals as effective venues for teenagers to quickly and anonymously obtain accurate information on sensitive issues.

Single-crystal diffraction at the Extreme Conditions beamline P02.2: procedure for collecting and analyzing high-pressure single-crystal data.

PubMed

Rothkirch, André; Gatta, G Diego; Meyer, Mathias; Merkel, Sébastien; Merlini, Marco; Liermann, Hanns Peter

2013-09-01

Fast detectors employed at third-generation synchrotrons have reduced collection times significantly and require the optimization of commercial as well as customized software packages for data reduction and analysis. In this paper a procedure to collect, process and analyze single-crystal data sets collected at high pressure at the Extreme Conditions beamline (P02.2) at PETRA III, DESY, is presented. A new data image format called `Esperanto' is introduced that is supported by the commercial software package CrysAlis(Pro) (Agilent Technologies UK Ltd). The new format acts as a vehicle to transform the most common area-detector data formats via a translator software. Such a conversion tool has been developed and converts tiff data collected on a Perkin Elmer detector, as well as data collected on a MAR345/555, to be imported into the CrysAlis(Pro) software. In order to demonstrate the validity of the new approach, a complete structure refinement of boron-mullite (Al5BO9) collected at a pressure of 19.4 (2) GPa is presented. Details pertaining to the data collections and refinements of B-mullite are presented.

The Classification of Tongue Colors with Standardized Acquisition and ICC Profile Correction in Traditional Chinese Medicine.

PubMed

Qi, Zhen; Tu, Li-Ping; Chen, Jing-Bo; Hu, Xiao-Juan; Xu, Jia-Tuo; Zhang, Zhi-Feng

2016-01-01

Background and Goal . The application of digital image processing techniques and machine learning methods in tongue image classification in Traditional Chinese Medicine (TCM) has been widely studied nowadays. However, it is difficult for the outcomes to generalize because of lack of color reproducibility and image standardization. Our study aims at the exploration of tongue colors classification with a standardized tongue image acquisition process and color correction. Methods . Three traditional Chinese medical experts are chosen to identify the selected tongue pictures taken by the TDA-1 tongue imaging device in TIFF format through ICC profile correction. Then we compare the mean value of L * a * b * of different tongue colors and evaluate the effect of the tongue color classification by machine learning methods. Results . The L * a * b * values of the five tongue colors are statistically different. Random forest method has a better performance than SVM in classification. SMOTE algorithm can increase classification accuracy by solving the imbalance of the varied color samples. Conclusions . At the premise of standardized tongue acquisition and color reproduction, preliminary objectification of tongue color classification in Traditional Chinese Medicine (TCM) is feasible.

High definition TV projection via single crystal faceplate technology

NASA Astrophysics Data System (ADS)

Kindl, H. J.; St. John, Thomas

1993-03-01

Single crystal phosphor faceplates are epitaxial phosphors grown on crystalline substrates with the advantages of high light output, resolution, and extended operational life. Single crystal phosphor faceplate industrial technology in the United States is capable of providing a faceplate appropriate to the projection industry of up to four (4) inches in diameter. Projection systems incorporating cathode ray tubes utilizing single crystal phosphor faceplates will produce 1500 lumens of white light with 1000 lines of resolution, non-interlaced. This 1500 lumen projection system will meet all of the currently specified luminance and resolution requirements of Visual Display systems for flight simulators. Significant logistic advantages accrue from the introduction of single crystal phosphor faceplate CRT's. Specifically, the full performance life of a CRT is expected to increase by a factor of five (5); ie, from 2000 to 10,000 hours of operation. There will be attendant reductions in maintenance time, spare CRT requirements, system down time, etc. The increased brightness of the projection system will allow use of lower gain, lower cost simulator screen material. Further, picture performance characteristics will be more balanced across the full simulator.

Increasing circular synthetic aperture sonar resolution via adapted wave atoms deconvolution.

PubMed

Pailhas, Yan; Petillot, Yvan; Mulgrew, Bernard

2017-04-01

Circular Synthetic Aperture Sonar (CSAS) processing computes coherently Synthetic Aperture Sonar (SAS) data acquired along a circular trajectory. This approach has a number of advantages, in particular it maximises the aperture length of a SAS system, producing very high resolution sonar images. CSAS image reconstruction using back-projection algorithms, however, introduces a dissymmetry in the impulse response, as the imaged point moves away from the centre of the acquisition circle. This paper proposes a sampling scheme for the CSAS image reconstruction which allows every point, within the full field of view of the system, to be considered as the centre of a virtual CSAS acquisition scheme. As a direct consequence of using the proposed resampling scheme, the point spread function (PSF) is uniform for the full CSAS image. Closed form solutions for the CSAS PSF are derived analytically, both in the image and the Fourier domain. The thorough knowledge of the PSF leads naturally to the proposed adapted atom waves basis for CSAS image decomposition. The atom wave deconvolution is successfully applied to simulated data, increasing the image resolution by reducing the PSF energy leakage.

Uranus' cloud structure and scattering particle properties from IRTF SpeX observations

NASA Astrophysics Data System (ADS)

Tice, D. S.; Irwin, P. G. J.; Fletcher, L. N.; Teanby, N. A.; Orton, G. S.; Davis, G. R.

2011-10-01

Observations of Uranus were made in August 2009 with the SpeX spectrograph at the NASA Infrared Telescope Facility (IRTF). Analysed spectra range from 0.8 to 1.8 μm at a spatial resolution of 0.5" and a spectral resolution of R = 1,200. Spectra from 0.818 to 0.834 μm, a region characterised by both strong hydrogen quadrupole and methane absorptions are considered to determine methane content. Evidence indicates that methane abundance varies with latitude. NEMESIS, an optimal estimation retrieval code with full-scattering capability, is employed to analyse the full range of data. Cloud and haze properties in the upper troposphere and stratosphere are characterised, and are consistent with other current literature. New information on single scattering albedos and particle size distributions are inferred.

A focal-spot diagnostic for on-shot characterization of high-energy petawatt lasers.

PubMed

Bromage, J; Bahk, S-W; Irwin, D; Kwiatkowski, J; Pruyne, A; Millecchia, M; Moore, M; Zuegel, J D

2008-10-13

An on-shot focal-spot diagnostic for characterizing high-energy, petawatt-class laser systems is presented. Accurate measurements at full energy are demonstrated using high-resolution wavefront sensing in combination with techniques to calibrate on-shot measurements with low-power sample beams. Results are shown for full-energy activation shots of the OMEGA EP Laser System.

Testing the PV-Theta Mapping Technique in a 3-D CTM Model Simulation

NASA Technical Reports Server (NTRS)

Frith, Stacey M.

2004-01-01

Mapping lower stratospheric ozone into potential vorticity (PV)- potential temperature (Theta) coordinates is a common technique employed to analyze sparse data sets. Ozone transformed into a flow-following dynamical coordinate system is insensitive to meteorological variations. Therefore data from a wide range of times/locations can be compared, so long as the measurements were made in the same airmass (as defined by PV). Moreover, once a relationship between ozone and PV/Theta is established, a full 3D ozone field can be estimated from this relationship and the 3D analyzed PV field. However, ozone data mapped in this fashion can be hampered by noisy PV fields, or "mis-matches" in the resolution and/or exact location of the ozone and PV measurements. In this study, we investigate the PV-ozone relationship using output from a recent 50-year run of the Goddard 3D chemical transport model (CTM). Model constituents are transported using off-line dynamics from the finite volume general circulation model (FVGCM). By using the internally consistent model PV and ozone fields, we minimize noise due to mis-matching and resolution issues. We calculate correlations between model ozone and PV throughout the stratosphere, and test the sensitivity of the technique to initial data resolution. To do this we degrade the model data to that of various satellite instruments, then compare the mapped fields derived from the sub-sampled data to the full resolution model data. With these studies we can determine appropriate limits for the PV-theta mapping technique in latitude, altitude, and as a function of original data resolution.

Evaluation of arctic multibeam sonar data quality using nadir crossover error analysis and compilation of a full-resolution data product

NASA Astrophysics Data System (ADS)

Flinders, Ashton F.; Mayer, Larry A.; Calder, Brian A.; Armstrong, Andrew A.

2014-05-01

We document a new high-resolution multibeam bathymetry compilation for the Canada Basin and Chukchi Borderland in the Arctic Ocean - United States Arctic Multibeam Compilation (USAMBC Version 1.0). The compilation preserves the highest native resolution of the bathymetric data, allowing for more detailed interpretation of seafloor morphology than has been previously possible. The compilation was created from multibeam bathymetry data available through openly accessible government and academic repositories. Much of the new data was collected during dedicated mapping cruises in support of the United States effort to map extended continental shelf regions beyond the 200 nm Exclusive Economic Zone. Data quality was evaluated using nadir-beam crossover-error statistics, making it possible to assess the precision of multibeam depth soundings collected from a wide range of vessels and sonar systems. Data were compiled into a single high-resolution grid through a vertical stacking method, preserving the highest quality data source in any specific grid cell. The crossover-error analysis and method of data compilation can be applied to other multi-source multibeam data sets, and is particularly useful for government agencies targeting extended continental shelf regions but with limited hydrographic capabilities. Both the gridded compilation and an easily distributed geospatial PDF map are freely available through the University of New Hampshire's Center for Coastal and Ocean Mapping (ccom.unh.edu/theme/law-sea). The geospatial pdf is a full resolution, small file-size product that supports interpretation of Arctic seafloor morphology without the need for specialized gridding/visualization software.

The Coast Artillery Journal. Volume 70, Number 1, January 1929

DTIC Science & Technology

1929-01-01

sovereign war-rights and liens on their future freedom of action. And for full measure, since measure you will have, let’s come nearer home. Have you...at their full value. Wait a bit, until the world gets used to a new idea. And remember that the League’s resolution of Septem- ber, 1927--to say...guns, planes, and ships, to block any possible blows until our full strength is developed, we will be a pretty dis. couraging proposition. Uncle Sam

Science Enabling Applications of Gridded Radiances and Products

NASA Astrophysics Data System (ADS)

Goldberg, M.; Wolf, W.; Zhou, L.

2005-12-01

New generations of hyperspectral sounders and imagers are not only providing vastly improved information to monitor, assess and predict the Earth's environment, they also provide tremendous volumes of data to manage. Key management challenges must include data processing, distribution, archive and utilization. At the NOAA/NESDIS Office of Research and Applications, we have started to address the challenge of utilizing high volume satellite by thinning observations and developing gridded datasets from the observations made from the NASA AIRS, AMSU and MODIS instrument. We have developed techniques for intelligent thinning of AIRS data for numerical weather prediction, by selecting the clearest AIRS 14 km field of view within a 3 x 3 array. The selection uses high spatial resolution 1 km MODIS data which are spatially convolved to the AIRS field of view. The MODIS cloud masks and AIRS cloud tests are used to select the clearest. During the real-time processing the data are thinned and gridded to support monitoring, validation and scientific studies. Products from AIRS, which includes profiles of temperature, water vapor and ozone and cloud-corrected infrared radiances for more than 2000 channels, are derived from a single AIRS/AMSU field of regard, which is a 3 x 3 array of AIRS footprints (each with a 14 km spatial resolution) collocated with a single AMSU footprint (42 km). One of our key gridded dataset is a daily 3 x 3 latitude/longitude projection which contains the nearest AIRS/AMSU field of regard with respect to the center of the 3 x 3 lat/lon grid. This particular gridded dataset is 1/40 the size of the full resolution data. This gridded dataset is the type of product request that can be used to support algorithm validation and improvements. It also provides for a very economical approach for reprocessing, testing and improving algorithms for climate studies without having to reprocess the full resolution data stored at the DAAC. For example, on a single CPU workstation, all the AIRS derived products can be derived from a single year of gridded data in 5 days. This relatively short turnaround time, which can be reduced considerably to 3 hours by using a cluster of 40 pc G5processors, allows for repeated reprocessing at the PIs home institution before substantial investments are made to reprocess the full resolution data sets archived at the DAAC. In other words, do not reprocess the full resolution data until the science community have tested and selected the optimal algorithm on the gridded data. Development and applications of gridded radiances and products will be discussed. The applications can be provided as part of a web-based service.

IGY celebrations

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

The House Science and Technology Committee unanimously approved a resolution to commemorate the 25th anniversary of the International Geophysical Year (IGY). The resolution, which also calls for House reaffirmation of its commitment to a ‘new, vigorous era of international cooperation in all the sciences,’ probably will be voted upon by the full House after Labor Day. If the resolution is passed, it will become an official statement of the House. As of mid-August, no similar resolution had been introduced in the Senate.‘We owe the scientists responsible for IGY more than a mere remembrance,’ said Rep. Tim Wirth (D., Colo.), sponsor of the resolution, in testimony before the House Science and Technology Committee on August 3. ‘We need to reaffirm our commitment to a new era of peaceful international cooperation in the sciences. My resolution reaffirms our commitment despite signals from the Reagan Administration that it is willing to diminish our participation in international science programs. Our nation cannot afford such a retreat,’ Wirth added, ‘and 1 fear our world cannot long survive in an atmosphere of conflict instead of cooperation.’

Coherent optical adaptive technique improves the spatial resolution of STED microscopy in thick samples

PubMed Central

Yan, Wei; Yang, Yanlong; Tan, Yu; Chen, Xun; Li, Yang; Qu, Junle; Ye, Tong

2018-01-01

Stimulated emission depletion microscopy (STED) is one of far-field optical microscopy techniques that can provide sub-diffraction spatial resolution. The spatial resolution of the STED microscopy is determined by the specially engineered beam profile of the depletion beam and its power. However, the beam profile of the depletion beam may be distorted due to aberrations of optical systems and inhomogeneity of specimens’ optical properties, resulting in a compromised spatial resolution. The situation gets deteriorated when thick samples are imaged. In the worst case, the sever distortion of the depletion beam profile may cause complete loss of the super resolution effect no matter how much depletion power is applied to specimens. Previously several adaptive optics approaches have been explored to compensate aberrations of systems and specimens. However, it is hard to correct the complicated high-order optical aberrations of specimens. In this report, we demonstrate that the complicated distorted wavefront from a thick phantom sample can be measured by using the coherent optical adaptive technique (COAT). The full correction can effectively maintain and improve the spatial resolution in imaging thick samples. PMID:29400356

Mediation Outcomes from the Second Sudan Civil War: An Analysis of Abuja and Igad Peace Initiatives

DTIC Science & Technology

2013-12-01

success rates as low as 5 percent for full resolution and 43 percent for partial settlement of conflicts. Given the low financial investment that...enormous financial , institutional, social, and human costs of violent conflict. If mediators can improve their understanding of what causes variation in...The Public Sector Mediation Process: A Theory and Empirical Examination,” Journal of Conflict Resolution 22, no 2 (June 1978): 236. 24 Dean G. Pruitt

Implications of RHESSI Observations for Solar Flare Models and Energetics

NASA Technical Reports Server (NTRS)

Holman, Gordon D.

2006-01-01

Observations of solar flares in X-rays and gamma-rays provide the most direct information about the hottest plasma and energetic electrons and ions accelerated in flares. The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) has observed over 18000 solar flares in X-rays and gamma-rays since its launch in February of 2002. RHESSI observes the full Sun at photon energies from as low as 3 keV to as high as 17 MeV with a spectral resolution on the order of 1 keV. It also provides images in arbitrary bands within this energy range with spatial resolution as good as 3 seconds of arc. Full images are typically produced every 4 seconds, although higher time resolution is possible. This unprecedented combination of spatial, spectral, and temporal resolution, spectral range and flexibility has led to fundamental advances in our understanding of flares. I will show RHESSI and coordinated observations that confirm coronal magnetic reconnection models for eruptive flares and coronal mass ejections, but also present new puzzles for these models. I will demonstrate how the analysis of RHESSI spectra has led to a better determination of the energy flux and total energy in accelerated electrons, and of the energy in the hot, thermal flare plasma. I will discuss how these energies compare with each other and with the energy contained in other flare-related phenomena such as interplanetary particles and coronal mass ejections.

Optical system analysis for the ground based EXVM

NASA Technical Reports Server (NTRS)

Hillman, L. W.; Chipman, R. A.; Smith, M. H.

1993-01-01

The MSFC's Experimental Vector Magnetograph (EXVM) is an instrument that observes a 4.4 x 8.8 arcmin field of the sun. The transverse and longitudinal components of the surface magnetic field and the line-of-sight velocities of the photospheric gases can be determined from polarimetric and spectral analysis of the 525.02 nm absorption line of Fe 1. The EXVM has been breadboarded and tested in the laboratory. The optics of the EXVM were tested with a point-diffraction (Smartt) interferometer. The 12 inch Cassegrain telescope was found to have 0.20 waves RMS (at 525.02 nm) of aberration. The post-telescope relay optics were nearly diffraction limited on-axis and had about one wave of primary coma as the predominant aberration at full-field. From theoretical modulation transfer function (MTF) curves of known aberrations, it was concluded that the EXVM should attain a maximum spatial resolution of about 0.5 arcseconds. A resolution test target indicated maximum angular resolutions better than 0.6 arcsec on-axis and 0.7 arcsec at full-field-of-view. A 2D inch heliostat (sun-tracking mirror) was used to direct sunlight into the lab and into the EXVM. Solar images obtained were limited by atmospheric seeing effects. During brief moments of good seeing, angular resolutions of about 1 arcsecond were realized with the EXVM.

Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry.

PubMed

Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

2010-11-01

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.

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

Low resolution spectroscopic investigation of Am stars using Automated method

NASA Astrophysics Data System (ADS)

Sharma, Kaushal; Joshi, Santosh; Singh, Harinder P.

2018-04-01

The automated method of full spectrum fitting gives reliable estimates of stellar atmospheric parameters (Teff, log g and [Fe/H]) for late A, F, G, and early K type stars. Recently, the technique was further improved in the cooler regime and the validity range was extended up to a spectral type of M6 - M7 (Teff˜ 2900 K). The present study aims to explore the application of this method on the low-resolution spectra of Am stars, a class of chemically peculiar stars, to examine its robustness for these objects. We use ULySS with the Medium-resolution INT Library of Empirical Spectra (MILES) V2 spectral interpolator for parameter determination. The determined Teff and log g values are found to be in good agreement with those obtained from high-resolution spectroscopy.

Nonlinear structured-illumination enhanced temporal focusing multiphoton excitation microscopy with a digital micromirror device.

PubMed

Cheng, Li-Chung; Lien, Chi-Hsiang; Da Sie, Yong; Hu, Yvonne Yuling; Lin, Chun-Yu; Chien, Fan-Ching; Xu, Chris; Dong, Chen Yuan; Chen, Shean-Jen

2014-08-01

In this study, the light diffraction of temporal focusing multiphoton excitation microscopy (TFMPEM) and the excitation patterning of nonlinear structured-illumination microscopy (NSIM) can be simultaneously and accurately implemented via a single high-resolution digital micromirror device. The lateral and axial spatial resolutions of the TFMPEM are remarkably improved through the second-order NSIM and projected structured light, respectively. The experimental results demonstrate that the lateral and axial resolutions are enhanced from 397 nm to 168 nm (2.4-fold) and from 2.33 μm to 1.22 μm (1.9-fold), respectively, in full width at the half maximum. Furthermore, a three-dimensionally rendered image of a cytoskeleton cell featuring ~25 nm microtubules is improved, with other microtubules at a distance near the lateral resolution of 168 nm also able to be distinguished.

The Modularized Software Package ASKI - Full Waveform Inversion Based on Waveform Sensitivity Kernels Utilizing External Seismic Wave Propagation Codes

NASA Astrophysics Data System (ADS)

Schumacher, F.; Friederich, W.

2015-12-01

We present the modularized software package ASKI which is a flexible and extendable toolbox for seismic full waveform inversion (FWI) as well as sensitivity or resolution analysis operating on the sensitivity matrix. It utilizes established wave propagation codes for solving the forward problem and offers an alternative to the monolithic, unflexible and hard-to-modify codes that have typically been written for solving inverse problems. It is available under the GPL at www.rub.de/aski. The Gauss-Newton FWI method for 3D-heterogeneous elastic earth models is based on waveform sensitivity kernels and can be applied to inverse problems at various spatial scales in both Cartesian and spherical geometries. The kernels are derived in the frequency domain from Born scattering theory as the Fréchet derivatives of linearized full waveform data functionals, quantifying the influence of elastic earth model parameters on the particular waveform data values. As an important innovation, we keep two independent spatial descriptions of the earth model - one for solving the forward problem and one representing the inverted model updates. Thereby we account for the independent needs of spatial model resolution of forward and inverse problem, respectively. Due to pre-integration of the kernels over the (in general much coarser) inversion grid, storage requirements for the sensitivity kernels are dramatically reduced.ASKI can be flexibly extended to other forward codes by providing it with specific interface routines that contain knowledge about forward code-specific file formats and auxiliary information provided by the new forward code. In order to sustain flexibility, the ASKI tools must communicate via file output/input, thus large storage capacities need to be accessible in a convenient way. Storing the complete sensitivity matrix to file, however, permits the scientist full manual control over each step in a customized procedure of sensitivity/resolution analysis and full waveform inversion.

The role of gas in determining image quality and resolution during in situ scanning transmission electron microscopy experiments

DOE PAGES

Zhu, Yuanyuan; Browning, Nigel D.

2017-05-24

As gas-solid heterogeneous catalytic reactions are molecular in nature, a full mechanistic understanding of the process requires atomic scale characterization under realistic operating conditions. While atomic resolution imaging has become a routine in modern high-vacuum (scanning) transmission electron microscopy ((S)TEM), both image quality and resolution nominally degrade when reaction gases are introduced. In this work, we systematically assess the effects of different gases at various pressures on the quality and resolution of images obtained at room temperature in the annular dark field STEM imaging mode using a differentially pumped (DP) gas cell. This imaging mode is largely free from inelasticmore » scattering effects induced by the presence of gases and retains good imaging properties over a wide range of gas mass/pressures. Furthermore, we demonstrate the application of the ESTEM with atomic resolution images of a complex oxide alkane oxidation catalyst MoVNbTeOx (M1) immersed in light and heavy gas environments.« less

Venus - Lakshmi Planum and Maxwell Montes

NASA Image and Video Library

1996-03-07

This full resolution radar image from NASA Magellan spacecraft is centered along the eastern edge of Lakshmi Planum and the western edge of Maxwell Montes. http://photojournal.jpl.nasa.gov/catalog/PIA00241

Two-Point Turbulence Closure Applied to Variable Resolution Modeling

NASA Technical Reports Server (NTRS)

Girimaji, Sharath S.; Rubinstein, Robert

2011-01-01

Variable resolution methods have become frontline CFD tools, but in order to take full advantage of this promising new technology, more formal theoretical development is desirable. Two general classes of variable resolution methods can be identified: hybrid or zonal methods in which RANS and LES models are solved in different flow regions, and bridging or seamless models which interpolate smoothly between RANS and LES. This paper considers the formulation of bridging methods using methods of two-point closure theory. The fundamental problem is to derive a subgrid two-equation model. We compare and reconcile two different approaches to this goal: the Partially Integrated Transport Model, and the Partially Averaged Navier-Stokes method.

Extreme ultraviolet performance of a multilayer coated high density toroidal grating

NASA Technical Reports Server (NTRS)

Thomas, Roger J.; Keski-Kuha, Ritva A. M.; Neupert, Werner M.; Condor, Charles E.; Gum, Jeffrey S.

1991-01-01

The performance of a multilayer coated diffraction grating has been evaluated at EUV wavelengths both in terms of absolute efficiency and spectral resolution. The application of ten-layer Ir/Si multilayer coating to a 3600-lines/mm blazed toroidal replica grating produced a factor of 9 enhancement in peak efficiency near the design wavelength of about 30 nm in first order, without degrading its excellent quasistigmatic spectral resolution. The measured EUV efficiency peaked at 3.3 percent and was improved over the full spectral range between 25 and 35 nm compared with the premultilayer replica which had a standard gold coating. In addition, the grating's spectral resolution of greater than 5000 was maintained.

Near-edge X-ray refraction fine structure microscopy

DOE PAGES

Farmand, Maryam; Celestre, Richard; Denes, Peter; ...

2017-02-06

We demonstrate a method for obtaining increased spatial resolution and specificity in nanoscale chemical composition maps through the use of full refractive reference spectra in soft x-ray spectro-microscopy. Using soft x-ray ptychography, we measure both the absorption and refraction of x-rays through pristine reference materials as a function of photon energy and use these reference spectra as the basis for decomposing spatially resolved spectra from a heterogeneous sample, thereby quantifying the composition at high resolution. While conventional instruments are limited to absorption contrast, our novel refraction based method takes advantage of the strongly energy dependent scattering cross-section and can seemore » nearly five-fold improved spatial resolution on resonance.« less

A Resolution in Service: SFX Usage Logs as a Basis for Link Resolver Menu Redesign

ERIC Educational Resources Information Center

Highsmith, Anne L.; Ponsford, Bennett Claire

2011-01-01

In this study, three years of SFX usage logs at Texas A&M University were analyzed to determine how patrons use link resolver services. The study contrasts the actions taken by users when full text is and is not available and compares public versus staff usage. The results confirmed users' preference for full-text services but also provided…

Fabrication and characterization of a 0.5-mm lutetium oxyorthosilicate detector array for high-resolution PET applications.

PubMed

Stickel, Jennifer R; Qi, Jinyi; Cherry, Simon R

2007-01-01

With the increasing use of in vivo imaging in mouse models of disease, there are many interesting applications that demand imaging of organs and tissues with submillimeter resolution. Though there are other contributing factors, the spatial resolution in small-animal PET is still largely determined by the detector pixel dimensions. In this work, a pair of lutetium oxyorthosilicate (LSO) arrays with 0.5-mm pixels was coupled to multichannel photomultiplier tubes and evaluated for use as high-resolution PET detectors. Flood histograms demonstrated that most crystals were clearly identifiable. Energy resolution varied from 22% to 38%. The coincidence timing resolution was 1.42-ns full width at half maximum (FWHM). The intrinsic spatial resolution was 0.68-mm FWHM as measured with a 30-gauge needle filled with (18)F. The improvement in spatial resolution in a tomographic setting is demonstrated using images of a line source phantom reconstructed with filtered backprojection and compared with images obtained from 2 dedicated small-animal PET scanners. Finally, a projection image of the mouse foot is shown to demonstrate the application of these 0.5-mm LSO detectors to a biologic task. A pair of highly pixelated LSO detections has been constructed and characterized for use as high-spatial-resolution PET detectors. It appears that small-animal PET systems capable of a FWHM spatial resolution of 600 microm or less are feasible and should be pursued.

Cluster finds giant gas vortices at the edge of Earth's magnetic bubble

NASA Astrophysics Data System (ADS)

2004-08-01

12 August 2004 ESA’s quartet of space-weather watchers, Cluster, has discovered vortices of ejected solar material high above the Earth. The superheated gases trapped in these structures are probably tunnelling their way into the Earth’s magnetic ‘bubble’, the magnetosphere. This discovery possibly solves a 17-year-mystery of how the magnetosphere is constantly topped up with electrified gases when it should be acting as a barrier. hi-res Size hi-res: 1446 Kb Credits: H. Hasegawa (Dartmouth College) Three-dimensional cut-away view of Earth's magnetosphere This figure shows a three-dimensional cut-away view of Earth' s magnetosphere. The curly features sketched on the boundary layer are the Kelvin-Helmholtz vortices discovered by Cluster. They originate where two adjacent flows travel with different speed. In this case, one of the flows is the heated gas inside the boundary layer of the magnetosphere, the other the solar wind just outside it. The arrows show the direction of the magnetic field, in red that associated with the solar wind and in green the one inside Earth’s magnetosphere. The white dashed arrow shows the trajectory followed by Cluster. High resolution version (JPG format) 1446 Kb High resolution version (TIFF format) 15 365 Kb hi-res Size hi-res: 22 Kb Credits: H. Hasegawa (Dartmouth College) Electrified gas varies across the vortices along Cluster’s trajectory This computer simulation shows how the density of the electrified gas is expected to vary across the vortices along Cluster’s trajectory (white dashed line). The density is lower inside the boundary layer (blue region) and higher outside, in the region dominated by the solar wind (shown in red). The density variations measured by the instruments on board Cluster match those predicted by this model. Low resolution version (JPG format) 22 Kb High resolution version (TIFF format) 3438 Kb The Earth’s magnetic field is our planet’s first line of defence against the bombardment of the solar wind. The solar wind itself is launched from the Sun and carries the Sun’s magnetic field throughout the Solar System. Sometimes this magnetic field is aligned with Earth’s and sometimes it points in the opposite direction. When the two fields point in opposite directions, scientists understand how ‘doors’ in Earth’s field can open. This phenomenon, called ‘magnetic reconnection’, allows the solar wind to flow in and collect in the reservoir known as the boundary layer. On the contrary, when the fields are aligned they should present an impenetrable barrier to the flow. However, spacecraft measurements of the boundary layer, dating back to 1987, present a puzzle because they clearly show that the boundary layer is fuller when the fields are aligned than when they are not. So how is the solar wind getting in? Thanks to the data from the four formation-flying spacecraft of ESA’s Cluster mission, scientists have made a breakthrough. On 20 November 2001, the Cluster flotilla was heading around from behind Earth and had just arrived at the dusk side of the planet, where the solar wind slides past Earth’s magnetosphere. There it began to encounter gigantic vortices of gas at the magnetopause, the outer ‘edge’ of the magnetosphere. “These vortices were really huge structures, about six Earth radii across,” says Hiroshi Hasegawa, Dartmouth College, New Hampshire who has been analysing the data with help from an international team of colleagues. Their results place the size of the vortices at almost 40 000 kilometres each, and this is the first time such structures have been detected. These vortices are known as products of Kelvin-Helmholtz instabilities (KHI). They can occur when two adjacent flows are travelling with different speeds, so one is slipping past the other. Good examples of such instabilities are the waves whipped up by the wind slipping across the surface of the ocean. Although KHI-waves had been observed before, this is the first time that vortices are actually detected. When a KHI-wave rolls up into a vortex, it becomes known as a ‘Kelvin Cat’s eye’. The data collected by Cluster have shown density variations of the electrified gas, right at the magnetopause, precisely like those expected when travelling through a ‘Kelvin Cat’s eye’. Scientists had postulated that, if these structures were to form at the magnetopause, they might be able to pull large quantities of the solar wind inside the boundary layer as they collapse. Once the solar wind particles are carried into the inner part of the magnetosphere, they can be excited strongly, allowing them to smash into Earth’s atmosphere and give rise to the aurorae. Cluster’s discovery strengthens this scenario but does not show the precise mechanism by which the gas is transported into Earth’s magnetic bubble. Thus, scientists still do not know whether this is the only process to fill up the boundary layer when the magnetic fields are aligned. For those measurements, Hasegawa says, scientists will have to wait for a future generation of magnetospheric satellites. Notes for editors The results of this investigation have appeared in today’s issue of the scientific journal Nature, in a paper entitled ‘Transport of solar wind into Earth's magnetosphere through rolled-up Kelvin-Helmholtz vortices’, by H. Hasegawa, M. Fujimoto, T.D. Phan, H. Reme, A. Balogh, M.W. Dunlop, C. Hashimoto and R. TanDokoro. More about magnetic reconnection Solar wind particles follow ‘magnetic field lines’, rather like beads on a wire. The ‘doors’ that open in Earth’s magnetosphere during oppositely aligned magnetic configurations are caused by a phenomenon called ‘magnetic reconnection‘. During this process, Earth’s field lines spontaneously break and join themselves to the Sun’s, allowing the solar wind to pass freely into Earth’s magnetosphere. Magnetic reconnections are not possible in the aligned case, however, hence the need for a different mechanism to inject the particles into Earth’s magnetosphere. More about Cluster Cluster is a mission of international co-operation between ESA and NASA. It involves four spacecraft, launched on two Russian rockets during the summer of 2000. They are now flying in formation around Earth, relaying the most detailed ever information about how the solar wind affects our planet in 3D. The solar wind is the perpetual stream of subatomic particles given out by the Sun and it can damage communications satellites and power stations on Earth. The Cluster mission is expected to continue until at least 2005. The ongoing archiving of the Cluster data (or Cluster Active Archive) is part of the International Living with a Star programme (ILWS), in which space agencies worldwide get together to investigate how variations in the Sun affect the environment of Earth and the other planets. In particular, ILWS concentrate on those aspects of the Sun-Earth system that may affect mankind and society. ILWS is a collaborative initiative between Europe, the United States, Russia, Japan and Canada.

http://www.esa.int/esaSC/Pr_21_2004_s_en.html

NASA Astrophysics Data System (ADS)

2004-09-01

X-ray brightness map hi-res Size hi-res: 38 Kb Credits: ESA/ XMM-Newton/ Patrick Henry et al. X-ray brightness map This map shows "surface brightness" or how luminous the region is. The larger of the two galaxy clusters is brighter, shown here as a white and red spot. A second cluster resides about "2 o'clock" from this, shown by a batch of yellow surrounded by green. Luminosity is related to density, so the densest regions (cluster cores) are the brightest regions. The white color corresponds to regions of the highest surface brightness, followed by red, orange, yellow, green, blue and purple. High resolution version (JPG format) 38 Kb High resolution version (TIFF format) 525 Kb Temperature map Credits: NASA Artist’s impression of cosmic head on collision The event details what the scientists are calling the perfect cosmic storm: galaxy clusters that collided like two high-pressure weather fronts and created hurricane-like conditions, tossing galaxies far from their paths and churning shock waves of 100-million-degree gas through intergalactic space. The tiny dots in this artist's concept are galaxies containing thousand million of stars. Animated GIF version Temperature map hi-res Size hi-res: 57 Kb Credits: ESA/ XMM-Newton/ Patrick Henry et al. Temperature map This image shows the temperature of gas in and around the two merging galaxy clusters, based directly on X-ray data. The galaxies themselves are difficult to identify; the image highlights the hot ‘invisible’ gas between the clusters heated by shock waves. The white colour corresponds to regions of the highest temperature - million of degrees, hotter than the surface of the Sun - followed by red, orange, yellow and blue. High resolution version (JPG format) 57 Kb High resolution version (TIFF format) 819 Kb The event details what the scientists are calling the ‘perfect cosmic storm’: galaxy clusters that collided like two high-pressure weather fronts and created hurricane-like conditions, tossing galaxies far from their paths and churning shock waves of 100-million-degree gas through intergalactic space. This unprecedented view of a merger in action crystallises the theory that the Universe built its magnificent hierarchal structure from the ‘bottom up’ - essentially through mergers of smaller galaxies and galaxy clusters into bigger ones. "Here before our eyes we see the making of one of the biggest objects in the Universe," said Dr Patrick Henry of the University of Hawaii, who led the study. "What was once two distinct but smaller galaxy clusters 300 million years ago is now one massive cluster in turmoil.” Henry and his colleagues, Alexis Finoguenov and Ulrich Briel of the Max-Planck Institute for Extraterrestrial Physics in Germany, present these results in an upcoming issue of the Astrophysical Journal. The forecast for the new super-cluster, they said, is 'clear and calm' now that the worst of the storm has passed. Galaxy clusters are the largest gravitationally bound structures in Universe, containing hundreds to thousands of galaxies. Our Milky Way galaxy is part of a small group of galaxies but is not gravitationally bound to the closest cluster, the Virgo Cluster. We are destined for a collision in a few thousand million years, though. The cluster named Abell 754 in the constellation Hydra has been known for decades. However, to the scientists' surprise, the new observation reveals that the merger may have occurred from the opposite direction than what was thought. They found evidence for this by tracing the wreckage today left in the merger's wake, spanning a distance of millions of light years. While other large mergers are known, none has been measured in such detail as Abell 754. For the first time, the scientists could create a complete ‘weather map’ of Abell 754 and thus determine a forecast. This map contains information about the temperature, pressure and density of the new cluster. As in all clusters, most the ordinary matter is in the form of gas between the galaxies and not locked up in the galaxies or stars themselves. The massive forces of the merging clusters accelerated intergalactic gas to great speeds. This resulted in shock waves that heat the gas to very high temperatures, which then radiated X-ray light, far more energetic than the visible light our eyes can detect. XMM-Newton, in orbit, detects this type of high-energy light. The dynamics of the merger revealed by XMM-Newton point to a cluster in transition. "One cluster has apparently smashed into the other from the 'north-west' and has since made one pass through," said Finoguenov. "Now, gravity will pull the remnants of this first cluster back towards the core of the second. Over the next few thousand million of years, the remnants of the clusters will settle and the merger will be complete." The observation implies that the largest structures in the Universe are essentially still forming in the modern era. Abell 754 is relatively close, about 800 million light years away. The construction boom may soon be over in a few more thousand million years though. A mysterious substance dubbed 'dark energy' appears to be accelerating the Universe's expansion rate. This means that objects are flying apart from each other at an ever-increasing speed and that clusters may eventually never have the opportunity to collide with each other. X-ray observations of galaxy clusters such as Abell 754 will help to better define dark energy and also dark matter, an ‘invisible’ and mysterious substance that appears to comprise over 80 percent of a galaxy cluster's mass. Notes for editors: This observation was announced at a NASA Internet press conference today. A paper describing these results, by Patrick Henry and his collaborators, will be published in the Astrophysical Journal. Images and other visual material are available at: http://www.gsfc.nasa.gov/topstory/2004/0831galaxymerger_media.html More about XMM-Newton ESA's XMM-Newton can detect more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket, from French Guiana. It is expected to return data for a decade. XMM-Newton's high-tech design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects.

Automated high resolution full-field spatial coherence tomography for quantitative phase imaging of human red blood cells

NASA Astrophysics Data System (ADS)

Singla, Neeru; Dubey, Kavita; Srivastava, Vishal; Ahmad, Azeem; Mehta, D. S.

2018-02-01

We developed an automated high-resolution full-field spatial coherence tomography (FF-SCT) microscope for quantitative phase imaging that is based on the spatial, rather than the temporal, coherence gating. The Red and Green color laser light was used for finding the quantitative phase images of unstained human red blood cells (RBCs). This study uses morphological parameters of unstained RBCs phase images to distinguish between normal and infected cells. We recorded the single interferogram by a FF-SCT microscope for red and green color wavelength and average the two phase images to further reduced the noise artifacts. In order to characterize anemia infected from normal cells different morphological features were extracted and these features were used to train machine learning ensemble model to classify RBCs with high accuracy.

Scanning fiber endoscopy with highly flexible, 1-mm catheterscopes for wide-field, full-color imaging

PubMed Central

Lee, Cameron M.; Engelbrecht, Christoph J.; Soper, Timothy D.; Helmchen, Fritjof; Seibel, Eric J.

2011-01-01

In modern endoscopy, wide field of view and full color are considered necessary for navigating inside the body, inspecting tissue for disease and guiding interventions such as biopsy or surgery. Current flexible endoscope technologies suffer from reduced resolution when device diameter shrinks. Endoscopic procedures today using coherent fiber bundle technology, on the scale of 1 mm, are performed with such poor image quality that the clinician’s vision meets the criteria for legal blindness. Here, we review a new and versatile scanning fiber imaging technology and describe its implementation for ultrathin and flexible endoscopy. This scanning fiber endoscope (SFE) or catheterscope enables high quality, laser-based, video imaging for ultrathin clinical applications while also providing new options for in vivo biological research of subsurface tissue and high resolution fluorescence imaging. PMID:20336702

Tissue imaging using full field optical coherence microscopy with short multimode fiber probe

NASA Astrophysics Data System (ADS)

Sato, Manabu; Eto, Kai; Goto, Tetsuhiro; Kurotani, Reiko; Abe, Hiroyuki; Nishidate, Izumi

2018-03-01

In achieving minimally invasive accessibility to deeply located regions the size of the imaging probes is important. We demonstrated full-field optical coherence tomography (FF-OCM) using an ultrathin forward-imaging short multimode fiber (SMMF) probe of 50 μm core diameter, 125 μm diameter, and 7.4 mm length for optical communications. The axial resolution was measured to be 2.14 μm and the lateral resolution was also evaluated to be below 4.38 μm using a test pattern (TP). The spatial mode and polarization characteristics of SMMF were evaluated. Inserting SMMF to in vivo rat brain, 3D images were measured and 2D information of nerve fibers was obtained. The feasibility of an SMMF as an ultrathin forward-imaging probe in FF-OCM has been demonstrated.

Applying LED in full-field optical coherence tomography for gastrointestinal endoscopy

NASA Astrophysics Data System (ADS)

Yang, Bor-Wen; Wang, Yu-Yen; Juan, Yu-Shan; Hsu, Sheng-Jie

2015-08-01

Optical coherence tomography (OCT) has become an important medical imaging technology due to its non-invasiveness and high resolution. Full-field optical coherence tomography (FF-OCT) is a scanning scheme especially suitable for en face imaging as it employs a CMOS/CCD device for parallel pixels processing. FF-OCT can also be applied to high-speed endoscopic imaging. Applying cylindrical scanning and a right-angle prism, we successfully obtained a 360° tomography of the inner wall of an intestinal cavity through an FF-OCT system with an LED source. The 10-μm scale resolution enables the early detection of gastrointestinal lesions, which can increase detection rates for esophageal, stomach, or vaginal cancer. All devices used in this system can be integrated by MOEMS technology to contribute to the studies of gastrointestinal medicine and advanced endoscopy technology.

Gas chromatographic quadrupole time-of-flight full scan high resolution mass spectrometric screening of human urine in antidoping analysis.

PubMed

Abushareeda, Wadha; Lyris, Emmanouil; Kraiem, Suhail; Wahaibi, Aisha Al; Alyazidi, Sameera; Dbes, Najib; Lommen, Arjen; Nielen, Michel; Horvatovich, Peter L; Alsayrafi, Mohammed; Georgakopoulos, Costas

2017-09-15

This paper presents the development and validation of a high-resolution full scan (FS) electron impact ionization (EI) gas chromatography coupled to quadrupole Time-of-Flight mass spectrometry (GC/QTOF) platform for screening anabolic androgenic steroids (AAS) in human urine samples. The World Antidoping Agency (WADA) enlists AAS as prohibited doping agents in sports, and our method has been developed to comply with the qualitative specifications of WADA to be applied for the detection of sports antidoping prohibited substances, mainly for AAS. The method also comprises of the quantitative analysis of the WADA's Athlete Biological Passport (ABP) endogenous steroidal parameters. The applied preparation of urine samples includes enzymatic hydrolysis for the cleavage of the Phase II glucuronide conjugates, generic liquid-liquid extraction and trimethylsilyl (TMS) derivatization steps. Tandem mass spectrometry (MS/MS) acquisition was applied on few selected ions to enhance the specificity and sensitivity of GC/TOF signal of few compounds. The full scan high resolution acquisition of analytical signal, for known and unknown TMS derivatives of AAS provides the antidoping system with a new analytical tool for the detection designer drugs and novel metabolites, which prolongs the AAS detection, after electronic data files' reprocessing. The current method is complementary to the respective liquid chromatography coupled to mass spectrometry (LC/MS) methodology widely used to detect prohibited molecules in sport, which cannot be efficiently ionized with atmospheric pressure ionization interface. Copyright © 2017 Elsevier B.V. All rights reserved.

Demosaicking for full motion video 9-band SWIR sensor

NASA Astrophysics Data System (ADS)

Kanaev, Andrey V.; Rawhouser, Marjorie; Kutteruf, Mary R.; Yetzbacher, Michael K.; DePrenger, Michael J.; Novak, Kyle M.; Miller, Corey A.; Miller, Christopher W.

2014-05-01

Short wave infrared (SWIR) spectral imaging systems are vital for Intelligence, Surveillance, and Reconnaissance (ISR) applications because of their abilities to autonomously detect targets and classify materials. Typically the spectral imagers are incapable of providing Full Motion Video (FMV) because of their reliance on line scanning. We enable FMV capability for a SWIR multi-spectral camera by creating a repeating pattern of 3x3 spectral filters on a staring focal plane array (FPA). In this paper we present the imagery from an FMV SWIR camera with nine discrete bands and discuss image processing algorithms necessary for its operation. The main task of image processing in this case is demosaicking of the spectral bands i.e. reconstructing full spectral images with original FPA resolution from spatially subsampled and incomplete spectral data acquired with the choice of filter array pattern. To the best of author's knowledge, the demosaicking algorithms for nine or more equally sampled bands have not been reported before. Moreover all existing algorithms developed for demosaicking visible color filter arrays with less than nine colors assume either certain relationship between the visible colors, which are not valid for SWIR imaging, or presence of one color band with higher sampling rate compared to the rest of the bands, which does not conform to our spectral filter pattern. We will discuss and present results for two novel approaches to demosaicking: interpolation using multi-band edge information and application of multi-frame super-resolution to a single frame resolution enhancement of multi-spectral spatially multiplexed images.

Color lensless digital holographic microscopy with micrometer resolution.

PubMed

Garcia-Sucerquia, Jorge

2012-05-15

Color digital lensless holographic microscopy with micrometer resolution is presented. Multiwavelength illumination of a biological sample and a posteriori color composition of the amplitude images individually reconstructed are used to obtain full-color representation of the microscopic specimen. To match the sizes of the reconstructed holograms for each wavelength, a reconstruction algorithm that allows for choosing the pixel size at the reconstruction plane independently of the wavelength and the reconstruction distance is used. The method is illustrated with experimental results.

State-of-the-art for large area high resolution gray scale and full color AC plasma flat panel displays

NASA Technical Reports Server (NTRS)

Stoller, Ray A.; Wedding, Donald K.; Friedman, Peter S.

1993-01-01

A development status evaluation is presented for gas plasma display technology, noting how tradeoffs among the parameters of size, resolution, speed, portability, color, and image quality can yield cost-effective solutions for medical imaging, CAD, teleconferencing, multimedia, and both civil and military applications. Attention is given to plasma-based large-area displays' suitability for radar, sonar, and IR, due to their lack of EM susceptibility. Both monochrome and color displays are available.

Development of Metallic Magnetic Calorimeters for Nuclear Safeguards Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bates, Cameron Russell

2015-03-11

Many nuclear safeguards applications could benefit from high-resolution gamma-ray spectroscopy achievable with metallic magnetic calorimeters. This dissertation covers the development of a system for these applications based on gamma-ray detectors developed at the University of Heidelberg. It demonstrates new calorimeters of this type, which achieved an energy resolution of 45.5 eV full-width at half-maximum at 59.54 keV, roughly ten times better than current state of the art high purity germanium detectors. This is the best energy resolution achieved with a gamma-ray metallic magnetic calorimeter at this energy to date. In addition to demonstrating a new benchmark in energy resolution, anmore » experimental system for measuring samples with metallic magnetic calorimeters was constructed at Lawrence Livermore National Laboratory. This system achieved an energy resolution of 91.3 eV full-width at half-maximum at 59.54 keV under optimal conditions. Using this system it was possible to characterize the linearity of the response, the count-rate limitations, and the energy resolution as a function of temperature of the new calorimeter. With this characterization it was determined that it would be feasible to measure 242Pu in a mixed isotope plutonium sample. A measurement of a mixed isotope plutonium sample was performed over the course of 12 days with a single two-pixel metallic magnetic calorimeter. The relative concentration of 242Pu in comparison to other plutonium isotopes was determined by direct measurement to less than half a percent accuracy. This is comparable with the accuracy of the best-case scenario using traditional indirect methods. The ability to directly measure the relative concentration of 242Pu in a sample could enable more accurate accounting and detection of indications of undeclared activities in nuclear safeguards, a better constraint on source material in forensic samples containing plutonium, and improvements in verification in a future plutonium disposition treaty.« less

Dynamic measurements of thermophysical properties of metals and alloys at high temperatures by subsecond pulse heating techniques

NASA Technical Reports Server (NTRS)

Cezairliyan, Ared

1993-01-01

Rapid (subsecond) heating techniques developed at the National Institute of Standards and Technology for the measurements of selected thermophysical and related properties of metals and alloys at high temperatures (above 1000 C) are described. The techniques are based on rapid resistive self-heating of the specimen from room temperature to the desired high temperature in short times and measuring the relevant experimental quantities, such as electrical current through the specimen, voltage across the specimen, specimen temperature, length, etc., with appropriate time resolution. The first technique, referred to as the millisecond-resolution technique, is for measurements on solid metals and alloys in the temperature range 1000 C to the melting temperature of the specimen. It utilizes a heavy battery bank for the energy source, and the total heating time of the specimen is typically in the range of 100-1000 ms. Data are recorded digitally every 0.5 ms with a full-scale resolution of about one part in 8000. The properties that can be measured with this system are as follows: specific heat, enthalpy, thermal expansion, electrical resistivity, normal spectral emissivity, hemispherical total emissivity, temperature and energy of solid-solid phase transformations, and melting temperature (solidus). The second technique, referred to as the microsecond-resolution technique, is for measurements on liquid metals and alloys in the temperature range 1200 to 6000 C. It utilizes a capacitor bank for the energy source, and the total heating time of the specimen is typically in the range 50-500 micro-s. Data are recorded digitally every 0.5 micro-s with a full-scale resolution of about one part in 4000. The properties that can be measured with this system are: melting temperature (solidus and liquidus), heat of fusion, specific heat, enthalpy, and electrical resistivity. The third technique is for measurements of the surface tension of liquid metals and alloys at their melting temperature. It utilizes a modified millisecond-resolution heating system designed for use in a microgravity environment.

Oculomotor nerve palsy by posterior communicating artery aneurysms: influence of surgical strategy on recovery.

PubMed

Güresir, Erdem; Schuss, Patrick; Seifert, Volker; Vatter, Hartmut

2012-11-01

Resolution of oculomotor nerve palsy (ONP) after clipping of posterior communicating artery (PCoA) aneurysms has been well documented. However, whether additional decompression of the oculomotor nerve via aneurysm sac dissection or resection is superior to pure aneurysm clipping is the subject of much debate. Therefore, the objective in the present investigation was to analyze the influence of surgical strategy--specifically, clipping with or without aneurysm dissection--on ONP resolution. Between June 1999 and December 2010, 18 consecutive patients with ruptured and unruptured PCoA aneurysms causing ONP were treated at the authors' institution. Oculomotor nerve palsy was evaluated on admission and at follow-up. The electronic database MEDLINE was searched for additional data in published studies of PCoA aneurysms causing ONP. Two reviewers independently extracted data. Overall, 8 studies from the literature review and 6 patients in the current series (121 PCoA aneurysms) met the study inclusion criteria. Ninety-four aneurysms were treated with simple aneurysm neck clipping and 27 with clipping plus aneurysm sac decompression. The surgical strategy, simple aneurysm neck clipping versus clipping plus oculomotor nerve decompression, had no effect on full ONP resolution on univariate (p = 0.5) and multivariate analyses. On multivariate analysis, patients with incomplete ONP at admission were more likely to have full resolution of the palsy than were those with complete ONP at admission (p = 0.03, OR = 4.2, 95% CI 1.1-16). Data in the present study indicated that ONP caused by PCoA aneurysms improves after clipping without and with oculomotor nerve decompression. The resolution of ONP is inversely associated with the initial severity of ONP.

Comparison of high resolution x-ray detectors with conventional FPDs using experimental MTFs and apodized aperture pixel design for reduced aliasing

NASA Astrophysics Data System (ADS)

Shankar, A.; Russ, M.; Vijayan, S.; Bednarek, D. R.; Rudin, S.

2017-03-01

Apodized Aperture Pixel (AAP) design, proposed by Ismailova et.al, is an alternative to the conventional pixel design. The advantages of AAP processing with a sinc filter in comparison with using other filters include non-degradation of MTF values and elimination of signal and noise aliasing, resulting in an increased performance at higher frequencies, approaching the Nyquist frequency. If high resolution small field-of-view (FOV) detectors with small pixels used during critical stages of Endovascular Image Guided Interventions (EIGIs) could also be extended to cover a full field-of-view typical of flat panel detectors (FPDs) and made to have larger effective pixels, then methods must be used to preserve the MTF over the frequency range up to the Nyquist frequency of the FPD while minimizing aliasing. In this work, we convolve the experimentally measured MTFs of an Microangiographic Fluoroscope (MAF) detector, (the MAF-CCD with 35μm pixels) and a High Resolution Fluoroscope (HRF) detector (HRF-CMOS50 with 49.5μm pixels) with the AAP filter and show the superiority of the results compared to MTFs resulting from moving average pixel binning and to the MTF of a standard FPD. The effect of using AAP is also shown in the spatial domain, when used to image an infinitely small point object. For detectors in neurovascular interventions, where high resolution is the priority during critical parts of the intervention, but full FOV with larger pixels are needed during less critical parts, AAP design provides an alternative to simple pixel binning while effectively eliminating signal and noise aliasing yet allowing the small FOV high resolution imaging to be maintained during critical parts of the EIGI.

Automatic Near-Real-Time Image Processing Chain for Very High Resolution Optical Satellite Data

NASA Astrophysics Data System (ADS)

Ostir, K.; Cotar, K.; Marsetic, A.; Pehani, P.; Perse, M.; Zaksek, K.; Zaletelj, J.; Rodic, T.

2015-04-01

In response to the increasing need for automatic and fast satellite image processing SPACE-SI has developed and implemented a fully automatic image processing chain STORM that performs all processing steps from sensor-corrected optical images (level 1) to web-delivered map-ready images and products without operator's intervention. Initial development was tailored to high resolution RapidEye images, and all crucial and most challenging parts of the planned full processing chain were developed: module for automatic image orthorectification based on a physical sensor model and supported by the algorithm for automatic detection of ground control points (GCPs); atmospheric correction module, topographic corrections module that combines physical approach with Minnaert method and utilizing anisotropic illumination model; and modules for high level products generation. Various parts of the chain were implemented also for WorldView-2, THEOS, Pleiades, SPOT 6, Landsat 5-8, and PROBA-V. Support of full-frame sensor currently in development by SPACE-SI is in plan. The proposed paper focuses on the adaptation of the STORM processing chain to very high resolution multispectral images. The development concentrated on the sub-module for automatic detection of GCPs. The initially implemented two-step algorithm that worked only with rasterized vector roads and delivered GCPs with sub-pixel accuracy for the RapidEye images, was improved with the introduction of a third step: super-fine positioning of each GCP based on a reference raster chip. The added step exploits the high spatial resolution of the reference raster to improve the final matching results and to achieve pixel accuracy also on very high resolution optical satellite data.

Middle cranial fossa approach for the repair of superior semicircular canal dehiscence is associated with greater symptom resolution compared to transmastoid approach.

PubMed

Nguyen, Thien; Lagman, Carlito; Sheppard, John P; Romiyo, Prasanth; Duong, Courtney; Prashant, Giyarpuram N; Gopen, Quinton; Yang, Isaac

2018-06-01

Superior semicircular canal dehiscence (SSCD) is a disorder of the skull base that is gaining increasing recognition among neurosurgeons. Traditionally, the middle cranial fossa (MCF) approach has been used for the surgical repair of SSCD. However, the transmastoid (TM) approach is an alternative strategy that has demonstrated promising results. We performed independent searches of a popular database to identify studies that described outcomes following the surgical repair of SSCD through MCF and TM approaches. The primary outcome was symptom resolution. Our analysis included 24 studies that described 230 patients that underwent either an MCF (n = 148, 64%) approach or a TM (n = 82, 36%) approach for primary surgical repair of SSCD. A greater percentage of patients in the MCF group experienced resolution of auditory symptoms (72% vs 59%, p = 0.012), aural fullness (83% vs 55%, p = 0.049), hearing loss (57% vs 31%, p = 0.026), and disequilibrium (75% vs 44%, p = 0.001) when compared to the TM group. The MCF approach was also associated with higher odds of symptom resolution for auditory symptoms (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.14-2.82), aural fullness (OR 4.02, 95% CI 1.04-15.53), hearing loss (OR 2.91, 95% CI 1.14-7.42), and disequilibrium (OR 3.94, 95% CI 1.78-8.73). The mean follow-up was 9 months. The literature suggests that the MCF approach for the repair of SSCD is associated with greater symptom resolution when compared to the TM approach. This information could help facilitate patient discussions.

Platinum replica electron microscopy: Imaging the cytoskeleton globally and locally.

PubMed

Svitkina, Tatyana M

2017-05-01

Structural studies reveal how smaller components of a system work together as a whole. However, combining high resolution of details with full coverage of the whole is challenging. In cell biology, light microscopy can image many cells in their entirety, but at a lower resolution, whereas electron microscopy affords very high resolution, but usually at the expense of the sample size and coverage. Structural analyses of the cytoskeleton are especially demanding, because cytoskeletal networks are unresolvable by light microscopy due to their density and intricacy, whereas their proper preservation is a challenge for electron microscopy. Platinum replica electron microscopy can uniquely bridge the gap between the "comfort zones" of light and electron microscopy by allowing high resolution imaging of the cytoskeleton throughout the entire cell and in many cells in the population. This review describes the principles and applications of platinum replica electron microscopy for studies of the cytoskeleton. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantitative criteria for assessment of gamma-ray imager performance

NASA Astrophysics Data System (ADS)

Gottesman, Steve; Keller, Kristi; Malik, Hans

2015-08-01

In recent years gamma ray imagers such as the GammaCamTM and Polaris have demonstrated good imaging performance in the field. Imager performance is often summarized as "resolution", either angular, or spatial at some distance from the imager, however the definition of resolution is not always related to the ability to image an object. It is difficult to quantitatively compare imagers without a common definition of image quality. This paper examines three categories of definition: point source; line source; and area source. It discusses the details of those definitions and which ones are more relevant for different situations. Metrics such as Full Width Half Maximum (FWHM), variations on the Rayleigh criterion, and some analogous to National Imagery Interpretability Rating Scale (NIIRS) are discussed. The performance against these metrics is evaluated for a high resolution coded aperture imager modeled using Monte Carlo N-Particle (MCNP), and for a medium resolution imager measured in the lab.

Platinum Replica Electron Microscopy: Imaging the Cytoskeleton Globally and Locally

PubMed Central

SVITKINA, Tatyana M.

2017-01-01

Structural studies reveal how smaller components of a system work together as a whole. However, combining high resolution of details with full coverage of the whole is challenging. In cell biology, light microscopy can image many cells in their entirety, but at a lower resolution, whereas electron microscopy affords very high resolution, but usually at the expense of the sample size and coverage. Structural analyses of the cytoskeleton are especially demanding, because cytoskeletal networks are unresolvable by light microscopy due to their density and intricacy, whereas their proper preservation is a challenge for electron microscopy. Platinum replica electron microscopy can uniquely bridge the gap between the “comfort zones” of light and electron microscopy by allowing high resolution imaging of the cytoskeleton throughout the entire cell and in many cells in the population. This review describes the principles and applications of platinum replica electron microscopy for studies of the cytoskeleton. PMID:28323208

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Yuanyuan; Browning, Nigel D.

As gas-solid heterogeneous catalytic reactions are molecular in nature, a full mechanistic understanding of the process requires atomic scale characterization under realistic operating conditions. While atomic resolution imaging has become a routine in modern high-vacuum (scanning) transmission electron microscopy ((S)TEM), both image quality and resolution nominally degrade when reaction gases are introduced. In this work, we systematically assess the effects of different gases at various pressures on the quality and resolution of images obtained at room temperature in the annular dark field STEM imaging mode using a differentially pumped (DP) gas cell. This imaging mode is largely free from inelasticmore » scattering effects induced by the presence of gases and retains good imaging properties over a wide range of gas mass/pressures. We demonstrate the application of the ESTEM with atomic resolution images of a complex oxide alkane oxidation catalyst MoVNbTeOx (M1) immersed in light and heavy gas environments.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Yuanyuan; Browning, Nigel D.

As gas-solid heterogeneous catalytic reactions are molecular in nature, a full mechanistic understanding of the process requires atomic scale characterization under realistic operating conditions. While atomic resolution imaging has become a routine in modern high-vacuum (scanning) transmission electron microscopy ((S)TEM), both image quality and resolution nominally degrade when reaction gases are introduced. In this work, we systematically assess the effects of different gases at various pressures on the quality and resolution of images obtained at room temperature in the annular dark field STEM imaging mode using a differentially pumped (DP) gas cell. This imaging mode is largely free from inelasticmore » scattering effects induced by the presence of gases and retains good imaging properties over a wide range of gas mass/pressures. Furthermore, we demonstrate the application of the ESTEM with atomic resolution images of a complex oxide alkane oxidation catalyst MoVNbTeOx (M1) immersed in light and heavy gas environments.« less

Nonlinear structured-illumination enhanced temporal focusing multiphoton excitation microscopy with a digital micromirror device

PubMed Central

Cheng, Li-Chung; Lien, Chi-Hsiang; Da Sie, Yong; Hu, Yvonne Yuling; Lin, Chun-Yu; Chien, Fan-Ching; Xu, Chris; Dong, Chen Yuan; Chen, Shean-Jen

2014-01-01

In this study, the light diffraction of temporal focusing multiphoton excitation microscopy (TFMPEM) and the excitation patterning of nonlinear structured-illumination microscopy (NSIM) can be simultaneously and accurately implemented via a single high-resolution digital micromirror device. The lateral and axial spatial resolutions of the TFMPEM are remarkably improved through the second-order NSIM and projected structured light, respectively. The experimental results demonstrate that the lateral and axial resolutions are enhanced from 397 nm to 168 nm (2.4-fold) and from 2.33 μm to 1.22 μm (1.9-fold), respectively, in full width at the half maximum. Furthermore, a three-dimensionally rendered image of a cytoskeleton cell featuring ~25 nm microtubules is improved, with other microtubules at a distance near the lateral resolution of 168 nm also able to be distinguished. PMID:25136483

High-resolution Ceres Low 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.

2017-06-01

The Dawn spacecraft Framing Camera (FC) acquired over 31,300 clear filter images of Ceres with a resolution of about 35 m/pxl during the eleven cycles in the Low Altitude Mapping Orbit (LAMO) phase between December 16 2015 and August 8 2016. We ortho-rectified the images from the first four cycles and produced a global, high-resolution, uncontrolled photomosaic of Ceres. This global mosaic is the basis for a high-resolution Ceres atlas that consists of 62 tiles mapped at a scale of 1:250,000. 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 [http://dawngis.dlr.de/atlas] and will become available through the NASA Planetary Data System (PDS) (http://pdssbn.astro.umd.edu/).

Characterization of a 2-mm thick, 16x16 Cadmium-Zinc-Telluride Pixel Array

NASA Technical Reports Server (NTRS)

Gaskin, Jessica; Richardson, Georgia; Mitchell, Shannon; Ramsey, Brian; Seller, Paul; Sharma, Dharma

2003-01-01

The detector under study is a 2-mm-thick, 16x16 Cadmium-Zinc-Telluride pixel array with a pixel pitch of 300 microns and inter-pixel gap of 50 microns. This detector is a precursor to that which will be used at the focal plane of the High Energy Replicated Optics (HERO) telescope currently being developed at Marshall Space Flight Center. With a telescope focal length of 6 meters, the detector needs to have a spatial resolution of around 200 microns in order to take full advantage of the HERO angular resolution. We discuss to what degree charge sharing will degrade energy resolution but will improve our spatial resolution through position interpolation. In addition, we discuss electric field modeling for this specific detector geometry and the role this mapping will play in terms of charge sharing and charge loss in the detector.

Signatures of Penumbral Magnetic Fields at Very High Spatial Resolution

NASA Astrophysics Data System (ADS)

Langhans, K.

2006-12-01

Full Stokes spectro-polarimetry, together with refined techniques to interpret the measurements and continual modeling efforts, have improved our understanding of sunspot penumbrae in the last years. In spite of this progress, an improvement in the spatial resolution of the observations is clearly needed to establish in a more direct way the fine structure of the penumbra. The discovery of dark penumbral cores by tet{l3 Sc02} suggests that we are starting to resolve the fundamental scales of the penumbra. Spectro-polarimetric measurements that are sensitive to the magnetic field in both the photosphere and higher layers, and obtained at a spatial resolution approaching 0.1 arcsec, may therefore allow us to draw firm conclusions about the fine scale organization of penumbral magnetic fields. In this paper I will discuss recent polarization measurements at very high spatial resolution, trying to reconcile the different scenarios put forward to explain the structure of the penumbra.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dickel, John R.; Gruendl, Robert A.; McIntyre, Vincent J.

Detailed 4.8 and 8.6 GHz radio images of the entire Small Magellanic Cloud with half-power beamwidths of 35'' at 4.8 GHz and 22'' at 8.6 GHz have been obtained using the Australia Telescope Compact Array. A total of 3564 mosaic positions were used to cover an area of 4.{sup 0}5 on a side. Full polarimetric observations were made. These images have sufficient spatial resolution ({approx}9 and 6 pc, respectively) and sensitivity (3{sigma} of 1.5 mJy beam{sup -1}) to identify most of the individual supernova remnants and H II regions and also, in combination with available data from the Parkes 64more » m telescope, the structure of the smooth emission in that galaxy. In addition, limited data using the sixth antenna at 4.5-6 km baselines are available to distinguish bright point sources (< 3 and 2 arcsec, respectively) and to help estimate sizes of individual sources smaller than the resolution of the full survey. The resultant database will be valuable for statistical studies and comparisons with X-ray, optical and infrared surveys of the Small Magellanic Cloud with similar resolution. The images and calibrated uv data are publicly available in FITS format.« less

Initial performance of the CUORE-0 experiment

DOE PAGES

Artusa, D. R.; Avignone, F. T.; Azzolini, O.; ...

2014-08-01

CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of 130Te. We present the first data analysis with 7.1kg • y of total TeO 2 exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay region of interest (2.47 to 2.57MeV) and in the α background-dominated region (2.70 to 3.90MeV) have been measured to be 0.071±0.011 and 0.019±0.002counts/(keV • kg • y), respectively. The latter result represents a factor of 6 improvement from a predecessor experiment, Cuoricino. The results verify our understanding of themore » background sources in CUORE-0, which is the basis of extrapolations to the full CUORE detector. The obtained energy resolution (full width at half maximum) in the region of interest is 5.7keV. Based on the measured background rate and energy resolution in the region of interest, CUORE-0 half-life sensitivity is expected to surpass the observed lower bound of Cuoricino with one year of live time.« less

Display device-adapted video quality-of-experience assessment

NASA Astrophysics Data System (ADS)

Rehman, Abdul; Zeng, Kai; Wang, Zhou

2015-03-01

Today's viewers consume video content from a variety of connected devices, including smart phones, tablets, notebooks, TVs, and PCs. This imposes significant challenges for managing video traffic efficiently to ensure an acceptable quality-of-experience (QoE) for the end users as the perceptual quality of video content strongly depends on the properties of the display device and the viewing conditions. State-of-the-art full-reference objective video quality assessment algorithms do not take into account the combined impact of display device properties, viewing conditions, and video resolution while performing video quality assessment. We performed a subjective study in order to understand the impact of aforementioned factors on perceptual video QoE. We also propose a full reference video QoE measure, named SSIMplus, that provides real-time prediction of the perceptual quality of a video based on human visual system behaviors, video content characteristics (such as spatial and temporal complexity, and video resolution), display device properties (such as screen size, resolution, and brightness), and viewing conditions (such as viewing distance and angle). Experimental results have shown that the proposed algorithm outperforms state-of-the-art video quality measures in terms of accuracy and speed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez, Jose A.; Ivanova, Magdalena I.; Sawaya, Michael R.

We report that the protein α-synuclein is the main component of Lewy bodies, the neuron-associated aggregates seen in Parkinson disease and other neurodegenerative pathologies. An 11-residue segment, which we term NACore, appears to be responsible for amyloid formation and cytotoxicity of human α-synuclein. Here we describe crystals of NACore that have dimensions smaller than the wavelength of visible light and thus are invisible by optical microscopy. As the crystals are thousands of times too small for structure determination by synchrotron X-ray diffraction, we use micro-electron diffraction to determine the structure at atomic resolution. The 1.4 Å resolution structure demonstrates thatmore » this method can determine previously unknown protein structures and here yields, to our knowledge, the highest resolution achieved by any cryo-electron microscopy method to date. The structure exhibits protofibrils built of pairs of face-to-face β-sheets. X-ray fibre diffraction patterns show the similarity of NACore to toxic fibrils of full-length α-synuclein. Finally, the NACore structure, together with that of a second segment, inspires a model for most of the ordered portion of the toxic, full-length α-synuclein fibril, presenting opportunities for the design of inhibitors of α-synuclein fibrils.« less

HRSCview: a web-based data exploration system for the Mars Express HRSC instrument

NASA Astrophysics Data System (ADS)

Michael, G.; Walter, S.; Neukum, G.

2007-08-01

The High Resolution Stereo Camera (HRSC) on the ESA Mars Express spacecraft has been orbiting Mars since January 2004. By spring 2007 it had returned around 2 terabytes of image data, covering around 35% of the Martian surface in stereo and colour at a resolu-tion of 10-20 m/pixel. HRSCview provides a rapid means to explore these images up to their full resolu-tion with the data-subsetting, sub-sampling, stretching and compositing being carried out on-the-fly by the image server. It is a joint website of the Free University of Berlin and the German Aerospace Center (DLR). The system operates by on-the-fly processing of the six HRSC level-4 image products: the map-projected ortho-rectified nadir pan-chromatic and four colour channels, and the stereo-derived DTM (digital terrain model). The user generates a request via the web-page for an image with several parameters: the centre of the view in surface coordinates, the image resolution in metres/pixel, the image dimensions, and one of several colour modes. If there is HRSC coverage at the given location, the necessary segments are extracted from the full orbit images, resampled to the required resolution, and composited according to the user's choice. In all modes the nadir channel, which has the highest resolu-tion, is included in the composite so that the maximum detail is always retained. The images are stretched ac-cording to the current view: this applies to the eleva-tion colour scale, as well as the nadir brightness and the colour channels. There are modes for raw colour, stretched colour, enhanced colour (exaggerated colour differences), and a synthetic 'Mars-like' colour stretch. A colour ratio mode is given as an alternative way to examine colour differences (R=IR/R, G=R/G and B=G/B). The final image is packaged as a JPEG file and returned to the user over the web. Each request requires approximately 1 second to process. A link is provided from each view to a data product page, where header items describing the full map-projected science data product are displayed, and a direct link to the archived data products on the ESA Planetary Science Archive (PSA) is provided. At pre-sent the majority of the elevation composites are de-rived from the HRSC Preliminary 200m DTMs gener-ated at the German Aerospace Center (DLR), which will not be available as separately downloadable data products. These DTMs are being progressively super-seded by systematically generated higher resolution archival DTMs, also from DLR, which will become available for download through the PSA, and be simi-larly accessible via HRSCview. At the time of writing this abstract (May 2007), four such high resolution DTMs are available for download via the HRSCview data product pages (for images from orbits 0572, 0905, 1004, and 2039).

High resolution global flood hazard map from physically-based hydrologic and hydraulic models.

NASA Astrophysics Data System (ADS)

Begnudelli, L.; Kaheil, Y.; McCollum, J.

2017-12-01

The global flood map published online at http://www.fmglobal.com/research-and-resources/global-flood-map at 90m resolution is being used worldwide to understand flood risk exposure, exercise certain measures of mitigation, and/or transfer the residual risk financially through flood insurance programs. The modeling system is based on a physically-based hydrologic model to simulate river discharges, and 2D shallow-water hydrodynamic model to simulate inundation. The model can be applied to large-scale flood hazard mapping thanks to several solutions that maximize its efficiency and the use of parallel computing. The hydrologic component of the modeling system is the Hillslope River Routing (HRR) hydrologic model. HRR simulates hydrological processes using a Green-Ampt parameterization, and is calibrated against observed discharge data from several publicly-available datasets. For inundation mapping, we use a 2D Finite-Volume Shallow-Water model with wetting/drying. We introduce here a grid Up-Scaling Technique (UST) for hydraulic modeling to perform simulations at higher resolution at global scale with relatively short computational times. A 30m SRTM is now available worldwide along with higher accuracy and/or resolution local Digital Elevation Models (DEMs) in many countries and regions. UST consists of aggregating computational cells, thus forming a coarser grid, while retaining the topographic information from the original full-resolution mesh. The full-resolution topography is used for building relationships between volume and free surface elevation inside cells and computing inter-cell fluxes. This approach almost achieves computational speed typical of the coarse grids while preserving, to a significant extent, the accuracy offered by the much higher resolution available DEM. The simulations are carried out along each river of the network by forcing the hydraulic model with the streamflow hydrographs generated by HRR. Hydrographs are scaled so that the peak corresponds to the return period corresponding to the hazard map being produced (e.g. 100 years, 500 years). Each numerical simulation models one river reach, except for the longest reaches which are split in smaller parts. Here we show results for selected river basins worldwide.

Curiosity Heat Shield in Detail

NASA Image and Video Library

2012-08-08

This color full-resolution image showing the heat shield of NASA Curiosity rover was obtained during descent to the surface of Mars. This image shows the inside surface of the heat shield, with its protective multi-layered insulation.

How to Use This Website | USDA Plant Hardiness Zone Map

Science.gov Websites

, regional or national plant hardiness zone maps in three different resolutions using the following steps. To default printing menu option or button. Viewing the Map - Open Full Map Button c. Save Full Map Button can copy the e-mail address and paste it into a different e-mail client (e.g., Google Gmail, Yahoo

Full load shop testing of 18,000-hp gas turbine driven centrifugal compressor for offshore platform service: Evaluation of rotor dynamics performance

NASA Technical Reports Server (NTRS)

Kirk, R. G.; Simpson, M.

1985-01-01

The results for in-plant full load testing of a 13.4 MW (18000 HP) gas turbine driven centrifugal compressor are presented and compared to analytical predictions of compressor rotor stability. Unique problems from both oil seals and labyrinth gas seals were encountered during the testing. The successful resolution of these problems are summarized.

Does resolution of flow field observation influence apparent habitat use and energy expenditure in juvenile coho salmon?

NASA Astrophysics Data System (ADS)

Tullos, D. D.; Walter, C.; Dunham, J.

2016-12-01

This study investigated how the resolution of observation influences interpretation of how fish, juvenile Coho Salmon (Oncorhynchus kisutch), exploit the hydraulic environment in streams. Our objectives were to evaluate how spatial resolution of the flow field observation influenced: 1) the velocities considered to be representative of habitat units; 2) patterns of use of the hydraulic environment by fish; and 3) estimates of energy expenditure. We addressed these objectives using observations within a 1:1 scale physical model of a full-channel log jam in an outdoor experimental stream. Velocities were measured with Acoustic Doppler Velocimetry at a 10 cm grid spacing, whereas fish locations and tailbeat frequencies were documented over time using underwater videogrammetry. Results highlighted that resolution of observation did impact perceived habitat use and energy expenditure, as did the location of measurement within habitat units and the use of averaging to summarize velocities within a habitat unit. In this experiment, the range of velocities and energy expenditure estimates increased with coarsening resolution, reducing the likelihood of measuring the velocities locally experienced by fish. In addition, the coarser resolutions contributed to fish appearing to select velocities that were higher than what was measured at finer resolutions. These findings indicate the need for careful attention to and communication of resolution of observation in investigating the hydraulic environment and in determining the habitat needs and bioenergetics of aquatic biota.

Next Generation Landsat Products Delivered Using Virtual Globes and OGC Standard Services

NASA Astrophysics Data System (ADS)

Neiers, M.; Dwyer, J.; Neiers, S.

2008-12-01

The Landsat Data Continuity Mission (LDCM) is the next in the series of Landsat satellite missions and is tasked with the objective of delivering data acquired by the Operational Land Imager (OLI). The OLI instrument will provide data continuity to over 30 years of global multispectral data collected by the Landsat series of satellites. The U.S. Geological Survey Earth Resources Observation and Science (USGS EROS) Center has responsibility for the development and operation of the LDCM ground system. One of the mission objectives of the LDCM is to distribute OLI data products electronically over the Internet to the general public on a nondiscriminatory basis and at no cost. To ensure the user community and general public can easily access LDCM data from multiple clients, the User Portal Element (UPE) of the LDCM ground system will use OGC standards and services such as Keyhole Markup Language (KML), Web Map Service (WMS), Web Coverage Service (WCS), and Geographic encoding of Really Simple Syndication (GeoRSS) feeds for both access to and delivery of LDCM products. The USGS has developed and tested the capabilities of several successful UPE prototypes for delivery of Landsat metadata, full resolution browse, and orthorectified (L1T) products from clients such as Google Earth, Google Maps, ESRI ArcGIS Explorer, and Microsoft's Virtual Earth. Prototyping efforts included the following services: using virtual globes to search the historical Landsat archive by dynamic generation of KML; notification of and access to new Landsat acquisitions and L1T downloads from GeoRSS feeds; Google indexing of KML files containing links to full resolution browse and data downloads; WMS delivery of reduced resolution browse, full resolution browse, and cloud mask overlays; and custom data downloads using WCS clients. These various prototypes will be demonstrated and LDCM service implementation plans will be discussed during this session.

3-D characterization of high-permeability zones in a gravel aquifer using 2-D crosshole GPR full-waveform inversion and waveguide detection

NASA Astrophysics Data System (ADS)

Klotzsche, Anja; van der Kruk, Jan; Linde, Niklas; Doetsch, Joseph; Vereecken, Harry

2013-11-01

Reliable high-resolution 3-D characterization of aquifers helps to improve our understanding of flow and transport processes when small-scale structures have a strong influence. Crosshole ground penetrating radar (GPR) is a powerful tool for characterizing aquifers due to the method's high-resolution and sensitivity to porosity and soil water content. Recently, a novel GPR full-waveform inversion algorithm was introduced, which is here applied and used for 3-D characterization by inverting six crosshole GPR cross-sections collected between four wells arranged in a square configuration close to the Thur River in Switzerland. The inversion results in the saturated part of this gravel aquifer reveals a significant improvement in resolution for the dielectric permittivity and electrical conductivity images compared to ray-based methods. Consistent structures where acquisition planes intersect indicate the robustness of the inversion process. A decimetre-scale layer with high dielectric permittivity was revealed at a depth of 5-6 m in all six cross-sections analysed here, and a less prominent zone with high dielectric permittivity was found at a depth of 7.5-9 m. These high-permittivity layers act as low-velocity waveguides and they are interpreted as high-porosity layers and possible zones of preferential flow. Porosity estimates from the permittivity models agree well with estimates from Neutron-Neutron logging data at the intersecting diagonal planes. Moreover, estimates of hydraulic permeability based on flowmeter logs confirm the presence of zones of preferential flow in these depth intervals. A detailed analysis of the measured data for transmitters located within the waveguides, revealed increased trace energy due to late-arrival elongated wave trains, which were observed for receiver positions straddling this zone. For the same receiver positions within the waveguide, a distinct minimum in the trace energy was visible when the transmitter was located outside the waveguide. A novel amplitude analysis was proposed to explore these maxima and minima of the trace energy. Laterally continuous low-velocity waveguides and their boundaries were identified in the measured data alone. In contrast to the full-waveform inversion, this method follows a simple workflow and needs no detailed and time consuming processing or inversion of the data. Comparison with the full-waveform inversion results confirmed the presence of the waveguides illustrating that full-waveform inversion return reliable results at the highest resolution currently possible at these scales. We envision that full-waveform inversion of GPR data will play an important role in a wide range of geological, hydrological, glacial and periglacial studies in the critical zone.

Preventive doping control screening analysis of prohibited substances in human urine using rapid-resolution liquid chromatography/high-resolution time-of-flight mass spectrometry.

PubMed

Vonaparti, A; Lyris, E; Angelis, Y S; Panderi, I; Koupparis, M; Tsantili-Kakoulidou, A; Peters, R J B; Nielen, M W F; Georgakopoulos, C

2010-06-15

Unification of the screening protocols for a wide range of doping agents has become an important issue for doping control laboratories. This study presents the development and validation of a generic liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) screening method of 241 small molecule analytes from various categories of prohibited substances (stimulants, narcotics, diuretics, beta(2)-agonists, beta-blockers, hormone antagonists and modulators, glucocorticosteroids and anabolic agents). It is based on a single-step liquid-liquid extraction of hydrolyzed urine and the use of a rapid-resolution liquid chromatography/high-resolution time-of-flight mass spectrometric system acquiring continuous full scan data. Electrospray ionization in the positive mode was used. Validation parameters consisted of identification capability, limit of detection, specificity, ion suppression, extraction recovery, repeatability and mass accuracy. Detection criteria were established on the basis of retention time reproducibility and mass accuracy. The suitability of the methodology for doping control was demonstrated with positive urine samples. The preventive role of the method was proved by the case where full scan acquisition with accurate mass measurement allowed the retrospective reprocessing of acquired data from past doping control samples for the detection of a designer drug, the stimulant 4-methyl-2-hexanamine, which resulted in re-reporting a number of stored samples as positives for this particular substance, when, initially, they had been reported as negatives. Copyright (c) 2010 John Wiley & Sons, Ltd.

High-resolution handheld rigid endomicroscope based on full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Benoit a la Guillaume, Emilie; Martins, Franck; Boccara, Claude; Harms, Fabrice

2016-02-01

Full-field optical coherence tomography (FF-OCT) is a powerful tool for nondestructive assessment of biological tissue, i.e., for the structural examination of tissue in depth at a cellular resolution. Mostly known as a microscopy device for ex vivo analysis, FF-OCT has also been adapted to endoscopy setups since it shows good potential for in situ cancer diagnosis and biopsy guidance. Nevertheless, all the attempts to perform endoscopic FF-OCT imaging did not go beyond lab setups. We describe here, to the best of our knowledge, the first handheld FF-OCT endoscope based on a tandem interferometry assembly using incoherent illumination. A common-path passive imaging interferometer at the tip of an optical probe makes it robust and insensitive to environmental perturbations, and a low finesse Fabry-Perot processing interferometer guarantees a compact system. A good resolution (2.7 μm transverse and 6 μm axial) is maintained through the long distance, small diameter relay optics of the probe, and a good signal-to-noise ratio is achieved in a limited 100 ms acquisition time. High-resolution images and a movie of a rat brain slice have been recorded by moving the contact endoscope over the surface of the sample, allowing for tissue microscopic exploration at 20 μm under the surface. These promising ex vivo results open new perspectives for in vivo imaging of biological tissue, in particular, in the field of cancer and surgical margin assessment.

Compact LED-based full-field optical coherence microscopy for high-resolution high-speed in vivo imaging

NASA Astrophysics Data System (ADS)

Ogien, Jonas; Dubois, Arnaud

2017-02-01

This work reports on a compact full-field optical coherence microscopy (FF-OCM) setup specifically designed to meet the needs for in vivo imaging, illuminated by a high-brightness broadband light emitting diode (LED). Broadband LEDs have spectra potentially large enough to provide imaging spatial resolutions similar to those reached using conventional halogen lamps, but their radiance can be much higher, which leads to high speed acquisition and makes in vivo imaging possible. We introduce a FF-OCM setup using a 2.3 W broadband LED, with an interferometer designed to be as compact as possible in order to provide the basis for a portable system that will make it possible to fully benefit from the capacity for in vivo imaging by providing the ability to image any region of interest in real-time. The interferometer part of the compact FF-OCM setup weighs 210 g for a size of 11x11x5 cm3. Using this setup, a sub-micron axial resolution was reached, with a detection sensitivity of 68 dB at an imaging rate of 250 Hz. Due to the high imaging rate, the sensitivity could be improved by accumulation while maintaining an acquisition time short enough for in vivo imaging. It was possible to reach a sensitivity of 75 dB at a 50 Hz imaging rate. High resolution in vivo human skin images were obtained with this setup and compared with images of excised human skin, showing high similarity.

High temporal resolution dynamic contrast-enhanced MRI using compressed sensing-combined sequence in quantitative renal perfusion measurement.

PubMed

Chen, Bin; Zhao, Kai; Li, Bo; Cai, Wenchao; Wang, Xiaoying; Zhang, Jue; Fang, Jing

2015-10-01

To demonstrate the feasibility of the improved temporal resolution by using compressed sensing (CS) combined imaging sequence in dynamic contrast-enhanced MRI (DCE-MRI) of kidney, and investigate its quantitative effects on renal perfusion measurements. Ten rabbits were included in the accelerated scans with a CS-combined 3D pulse sequence. To evaluate the image quality, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between the proposed CS strategy and the conventional full sampling method. Moreover, renal perfusion was estimated by using the separable compartmental model in both CS simulation and realistic CS acquisitions. The CS method showed DCE-MRI images with improved temporal resolution and acceptable image contrast, while presenting significantly higher SNR than the fully sampled images (p<.01) at 2-, 3- and 4-X acceleration. In quantitative measurements, renal perfusion results were in good agreement with the fully sampled one (concordance correlation coefficient=0.95, 0.91, 0.88) at 2-, 3- and 4-X acceleration in CS simulation. Moreover, in realistic acquisitions, the estimated perfusion by the separable compartmental model exhibited no significant differences (p>.05) between each CS-accelerated acquisition and the full sampling method. The CS-combined 3D sequence could improve the temporal resolution for DCE-MRI in kidney while yielding diagnostically acceptable image quality, and it could provide effective measurements of renal perfusion. Copyright © 2015 Elsevier Inc. All rights reserved.

Integrating expert- and algorithm-derived data to generate a hemispheric ice edge

NASA Astrophysics Data System (ADS)

Tsatsoulis, C.; Komp, E.

The Arctic ice edge is the area of the Arctic where sea ice concentration is less than 15%, and is considered navigable by most vessels. Experts at the National Ice Center generate a daily ice edge product that is available to the public. Data of preference is that of active, high resolution satellite sensors such as RADARSAT which yields all-weather images of 100m resolution, and a second source is OLS data with 550m resolution. Unfortunately, RADARSAT does not provide full, daily coverage of the Arctic and OLS can be obscured by clouds. The SSM/I sensor provides complete coverage of the Arctic at 25km resolution and is independent of cloud cover and solar illumination during the Arctic winter. SSM/I data is analyzed by the NASA Team algorithm to establish ice concentration. Our work integrates the ice edge created by experts using high resolution data with the ice edge generated out of the coarser SSM/I microwave data. The result is a product that combines human and algorithmic outputs, deals with gross differences in resolution of the underlying data sets, and results in a useful, operational product.

Circuit for high resolution decoding of multi-anode microchannel array detectors

NASA Technical Reports Server (NTRS)

Kasle, David B. (Inventor)

1995-01-01

A circuit for high resolution decoding of multi-anode microchannel array detectors consisting of input registers accepting transient inputs from the anode array; anode encoding logic circuits connected to the input registers; midpoint pipeline registers connected to the anode encoding logic circuits; and pixel decoding logic circuits connected to the midpoint pipeline registers is described. A high resolution algorithm circuit operates in parallel with the pixel decoding logic circuit and computes a high resolution least significant bit to enhance the multianode microchannel array detector's spatial resolution by halving the pixel size and doubling the number of pixels in each axis of the anode array. A multiplexer is connected to the pixel decoding logic circuit and allows a user selectable pixel address output according to the actual multi-anode microchannel array detector anode array size. An output register concatenates the high resolution least significant bit onto the standard ten bit pixel address location to provide an eleven bit pixel address, and also stores the full eleven bit pixel address. A timing and control state machine is connected to the input registers, the anode encoding logic circuits, and the output register for managing the overall operation of the circuit.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levegruen, Sabine, E-mail: sabine.levegruen@uni-due.de; Poettgen, Christoph; Abu Jawad, Jehad

Purpose: To evaluate megavoltage computed tomography (MVCT)-based image guidance with helical tomotherapy in patients with vertebral tumors by analyzing factors influencing interobserver variability, considered as quality criterion of image guidance. Methods and Materials: Five radiation oncologists retrospectively registered 103 MVCTs in 10 patients to planning kilovoltage CTs by rigid transformations in 4 df. Interobserver variabilities were quantified using the standard deviations (SDs) of the distributions of the correction vector components about the observers' fraction mean. To assess intraobserver variabilities, registrations were repeated after {>=}4 weeks. Residual deviations after setup correction due to uncorrectable rotational errors and elastic deformations were determinedmore » at 3 craniocaudal target positions. To differentiate observer-related variations in minimizing these residual deviations across the 3-dimensional MVCT from image resolution effects, 2-dimensional registrations were performed in 30 single transverse and sagittal MVCT slices. Axial and longitudinal MVCT image resolutions were quantified. For comparison, image resolution of kilovoltage cone-beam CTs (CBCTs) and interobserver variability in registrations of 43 CBCTs were determined. Results: Axial MVCT image resolution is 3.9 lp/cm. Longitudinal MVCT resolution amounts to 6.3 mm, assessed as full-width at half-maximum of thin objects in MVCTs with finest pitch. Longitudinal CBCT resolution is better (full-width at half-maximum, 2.5 mm for CBCTs with 1-mm slices). In MVCT registrations, interobserver variability in the craniocaudal direction (SD 1.23 mm) is significantly larger than in the lateral and ventrodorsal directions (SD 0.84 and 0.91 mm, respectively) and significantly larger compared with CBCT alignments (SD 1.04 mm). Intraobserver variabilities are significantly smaller than corresponding interobserver variabilities (variance ratio [VR] 1.8-3.1). Compared with 3-dimensional registrations, 2-dimensional registrations have significantly smaller interobserver variability in the lateral and ventrodorsal directions (VR 3.8 and 2.8, respectively) but not in the craniocaudal direction (VR 0.75). Conclusion: Tomotherapy image guidance precision is affected by image resolution and residual deviations after setup correction. Eliminating the effect of residual deviations yields small interobserver variabilities with submillimeter precision in the axial plane. In contrast, interobserver variability in the craniocaudal direction is dominated by the poorer longitudinal MVCT image resolution. Residual deviations after image guidance exist and need to be considered when dose gradients ultimately achievable with image guided radiation therapy techniques are analyzed.« less

Global Multi-Resolution Topography (GMRT) Synthesis - Version 2.0

NASA Astrophysics Data System (ADS)

Ferrini, V.; Coplan, J.; Carbotte, S. M.; Ryan, W. B.; O'Hara, S.; Morton, J. J.

2010-12-01

The detailed morphology of the global ocean floor is poorly known, with most areas mapped only at low resolution using satellite-based measurements. Ship-based sonars provide data at resolution sufficient to quantify seafloor features related to the active processes of erosion, sediment flow, volcanism, and faulting. To date, these data have been collected in a small fraction of the global ocean (<10%). The Global Multi-Resolution Topography (GMRT) synthesis makes use of sonar data collected by scientists and institutions worldwide, merging them into a single continuously updated compilation of high-resolution seafloor topography. Several applications, including GeoMapApp (http://www.geomapapp.org) and Virtual Ocean (http://www.virtualocean.org), make use of the GMRT Synthesis and provide direct access to images and underlying gridded data. Source multibeam files included in the compilation can also accessed through custom functionality in GeoMapApp. The GMRT Synthesis began in 1992 as the Ridge Multibeam Synthesis. It was subsequently expanded to include bathymetry data from the Southern Ocean, and now includes data from throughout the global oceans. Our design strategy has been to make data available at the full native resolution of shipboard sonar systems, which historically has been ~100 m in the deep sea (Ryan et al., 2009). A new release of the GMRT Synthesis in Fall of 2010 includes several significant improvements over our initial strategy. In addition to increasing the number of cruises included in the compilation by over 25%, we have developed a new protocol for handling multibeam source data, which has improved the overall quality of the compilation. The new tileset also includes a discrete layer of sonar data in the public domain that are gridded to the full resolution of the sonar system, with data gridded 25 m in some areas. This discrete layer of sonar data has been provided to Google for integration into Google’s default ocean base map. NOAA coastal grids and numerous grids contributed by the international science community are also integrated into the GMRT Synthesis. Finally, terrestrial elevation data from NASA’s ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) global DEM, and the USGS National Elevation Dataset have been included in the synthesis, providing resolution of up to 10 m in some areas of the US.

Megavoltage computed tomography image guidance with helical tomotherapy in patients with vertebral tumors: analysis of factors influencing interobserver variability.

PubMed

Levegrün, Sabine; Pöttgen, Christoph; Jawad, Jehad Abu; Berkovic, Katharina; Hepp, Rodrigo; Stuschke, Martin

2013-02-01

To evaluate megavoltage computed tomography (MVCT)-based image guidance with helical tomotherapy in patients with vertebral tumors by analyzing factors influencing interobserver variability, considered as quality criterion of image guidance. Five radiation oncologists retrospectively registered 103 MVCTs in 10 patients to planning kilovoltage CTs by rigid transformations in 4 df. Interobserver variabilities were quantified using the standard deviations (SDs) of the distributions of the correction vector components about the observers' fraction mean. To assess intraobserver variabilities, registrations were repeated after ≥4 weeks. Residual deviations after setup correction due to uncorrectable rotational errors and elastic deformations were determined at 3 craniocaudal target positions. To differentiate observer-related variations in minimizing these residual deviations across the 3-dimensional MVCT from image resolution effects, 2-dimensional registrations were performed in 30 single transverse and sagittal MVCT slices. Axial and longitudinal MVCT image resolutions were quantified. For comparison, image resolution of kilovoltage cone-beam CTs (CBCTs) and interobserver variability in registrations of 43 CBCTs were determined. Axial MVCT image resolution is 3.9 lp/cm. Longitudinal MVCT resolution amounts to 6.3 mm, assessed as full-width at half-maximum of thin objects in MVCTs with finest pitch. Longitudinal CBCT resolution is better (full-width at half-maximum, 2.5 mm for CBCTs with 1-mm slices). In MVCT registrations, interobserver variability in the craniocaudal direction (SD 1.23 mm) is significantly larger than in the lateral and ventrodorsal directions (SD 0.84 and 0.91 mm, respectively) and significantly larger compared with CBCT alignments (SD 1.04 mm). Intraobserver variabilities are significantly smaller than corresponding interobserver variabilities (variance ratio [VR] 1.8-3.1). Compared with 3-dimensional registrations, 2-dimensional registrations have significantly smaller interobserver variability in the lateral and ventrodorsal directions (VR 3.8 and 2.8, respectively) but not in the craniocaudal direction (VR 0.75). Tomotherapy image guidance precision is affected by image resolution and residual deviations after setup correction. Eliminating the effect of residual deviations yields small interobserver variabilities with submillimeter precision in the axial plane. In contrast, interobserver variability in the craniocaudal direction is dominated by the poorer longitudinal MVCT image resolution. Residual deviations after image guidance exist and need to be considered when dose gradients ultimately achievable with image guided radiation therapy techniques are analyzed. Copyright © 2013 Elsevier Inc. All rights reserved.

Resolution analysis of archive films for the purpose of their optimal digitization and distribution

NASA Astrophysics Data System (ADS)

Fliegel, Karel; Vítek, Stanislav; Páta, Petr; Myslík, Jiří; Pecák, Josef; Jícha, Marek

2017-09-01

With recent high demand for ultra-high-definition (UHD) content to be screened in high-end digital movie theaters but also in the home environment, film archives full of movies in high-definition and above are in the scope of UHD content providers. Movies captured with the traditional film technology represent a virtually unlimited source of UHD content. The goal to maintain complete image information is also related to the choice of scanning resolution and spatial resolution for further distribution. It might seem that scanning the film material in the highest possible resolution using state-of-the-art film scanners and also its distribution in this resolution is the right choice. The information content of the digitized images is however limited, and various degradations moreover lead to its further reduction. Digital distribution of the content in the highest image resolution might be therefore unnecessary or uneconomical. In other cases, the highest possible resolution is inevitable if we want to preserve fine scene details or film grain structure for archiving purposes. This paper deals with the image detail content analysis of archive film records. The resolution limit in captured scene image and factors which lower the final resolution are discussed. Methods are proposed to determine the spatial details of the film picture based on the analysis of its digitized image data. These procedures allow determining recommendations for optimal distribution of digitized video content intended for various display devices with lower resolutions. Obtained results are illustrated on spatial downsampling use case scenario, and performance evaluation of the proposed techniques is presented.

Development of a stationary digital breast tomosynthesis system for clinical applications

NASA Astrophysics Data System (ADS)

Tucker, Andrew Wallace

Digital breast tomosynthesis (DBT) has been shown to be a very beneficial tool in the fight against breast cancer. However, current DBT systems have poor spatial resolution compared to full field digital mammography (FFDM), the current gold standard for screening mammography. The poor spatial resolution of DBT systems is a result of the single X-ray source design. In DBT systems a single X-ray source is rotated over an angular span in order to acquire the images needed for 3D reconstruction. The rotation of the X-ray source degrades the spatial resolution of the images. DBT systems which are approved for use in the United States for screening mammography are required to also take a full field digital mammogram with every DBT acquisition in order to compensate for the poor spatial resolution. This double exposure essentially doubles the radiation dose to patients. Over the past few years our research group has developed a carbon nanotube (CNT) based X-ray source technology. The unique nature of CNT X-ray sources allows for multiple X-ray focal spots in a single X-ray source. Using this technology we have recently developed a stationary DBT system (s-DBT) system which is capable of producing a full tomosynthesis image dataset with zero motion of the X-ray source. This system has been shown to have increased spatial resolution over other DBT systems in a laboratory setting. The goal of this thesis work was to optimize the s-DBT system, demonstrate its usefulness over other systems, and finally implement it into the clinic for a clinical trial. The s-DBT system was optimized using different image quality measurements. The optimized system was then used in a breast specimen imaging trial which compared s-DBT to magnified 2D mammography and a conventional single source DBT system. Readers preferred s-DBT to magnified 2D mammography for specimen margin delineation and mass detection, these results were not significant. Using physical measures for spatial resolution the s-DBT system was shown to have improved image quality over conventional single source DBT systems in breast tissue. A separate study showed that s-DBT could be a feasible alternative to FFDM for screening patients with breast implants. Finally, a second s-DBT system was constructed and implemented into the Department of Mammography at UNC hospitals. The first patient was imaged on the system in December of 2013.

Latent palmprint matching.

PubMed

Jain, Anil K; Feng, Jianjiang

2009-06-01

The evidential value of palmprints in forensic applications is clear as about 30 percent of the latents recovered from crime scenes are from palms. While biometric systems for palmprint-based personal authentication in access control type of applications have been developed, they mostly deal with low-resolution (about 100 ppi) palmprints and only perform full-to-full palmprint matching. We propose a latent-to-full palmprint matching system that is needed in forensic applications. Our system deals with palmprints captured at 500 ppi (the current standard in forensic applications) or higher resolution and uses minutiae as features to be compatible with the methodology used by latent experts. Latent palmprint matching is a challenging problem because latent prints lifted at crime scenes are of poor image quality, cover only a small area of the palm, and have a complex background. Other difficulties include a large number of minutiae in full prints (about 10 times as many as fingerprints), and the presence of many creases in latents and full prints. A robust algorithm to reliably estimate the local ridge direction and frequency in palmprints is developed. This facilitates the extraction of ridge and minutiae features even in poor quality palmprints. A fixed-length minutia descriptor, MinutiaCode, is utilized to capture distinctive information around each minutia and an alignment-based minutiae matching algorithm is used to match two palmprints. Two sets of partial palmprints (150 live-scan partial palmprints and 100 latent palmprints) are matched to a background database of 10,200 full palmprints to test the proposed system. Despite the inherent difficulty of latent-to-full palmprint matching, rank-1 recognition rates of 78.7 and 69 percent, respectively, were achieved in searching live-scan partial palmprints and latent palmprints against the background database.

Advanced Concept

NASA Image and Video Library

2008-02-15

Testing of the subsonic and transonic mach number for clean and full protuberances in support of the Ares/CLV Integrated Vehicle at the Boeing facility in Missouri. This image is extracted from a high definition video file and is the highest resolution available.

A PRESTO-SENSE sequence with alternating partial-Fourier encoding for rapid susceptibility-weighted 3D MRI time series.

PubMed

Klarhöfer, Markus; Dilharreguy, Bixente; van Gelderen, Peter; Moonen, Chrit T W

2003-10-01

A 3D sequence for dynamic susceptibility imaging is proposed which combines echo-shifting principles (such as PRESTO), sensitivity encoding (SENSE), and partial-Fourier acquisition. The method uses a moderate SENSE factor of 2 and takes advantage of an alternating partial k-space acquisition in the "slow" phase encode direction allowing an iterative reconstruction using high-resolution phase estimates. Offering an isotropic spatial resolution of 4 x 4 x 4 mm(3), the novel sequence covers the whole brain including parts of the cerebellum in 0.5 sec. Its temporal signal stability is comparable to that of a full-Fourier, full-FOV EPI sequence having the same dynamic scan time but much less brain coverage. Initial functional MRI experiments showed consistent activation in the motor cortex with an average signal change slightly less than that of EPI. Copyright 2003 Wiley-Liss, Inc.

Spatial coherence effect on layer thickness determination in narrowband full-field optical coherence tomography.

PubMed

Safrani, Avner; Abdulhalim, Ibrahim

2011-06-20

Longitudinal spatial coherence (LSC) is determined by the spatial frequency content of an optical beam. The use of lenses with a high numerical aperture (NA) in full-field optical coherence tomography and a narrowband light source makes the LSC length much shorter than the temporal coherence length, hence suggesting that high-resolution 3D images of biological and multilayered samples can be obtained based on the low LSC. A simplified model is derived, supported by experimental results, which describes the expected interference output signal of multilayered samples when high-NA lenses are used together with a narrowband light source. An expression for the correction factor for the layer thickness determination is found valid for high-NA objectives. Additionally, the method was applied to a strongly scattering layer, demonstrating the potential of this method for high-resolution imaging of scattering media.

A Low-Noise Germanium Ionization Spectrometer for Low-Background Science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aalseth, Craig E.; Colaresi, Jim; Collar, Juan I.

2016-12-01

Recent progress on the development of very low energy threshold high purity germanium ionization spectrometers has produced an instrument of 1.2 kg mass and excellent noise performance. The detector was installed in a low-background cryostat intended for use in a low mass, WIMP dark matter direct detection search. The integrated detector and low background cryostat achieved noise performance of 98 eV full-width half-maximum of an input electronic pulse generator peak and gamma-ray energy resolution of 1.9 keV full-width half-maximum at the 60Co gamma-ray energy of 1332 keV. This Transaction reports the thermal characterization of the low-background cryostat, specifications of themore » newly prepared 1.2 kg p-type point contact germanium detector, and the ionization spectroscopy – energy resolution and energy threshold – performance of the integrated system.« less

A Three-Dimensional Microdisplacement Sensing System Based on MEMS Bulk-Silicon Technology

PubMed Central

Wu, Junjie; Lei, Lihua; Chen, Xin; Cai, Xiaoyu; Li, Yuan; Han, Tao

2014-01-01

For the dimensional measurement and characterization of microsized and nanosized components, a three-dimensional microdisplacement sensing system was developed using the piezoresistive effect in silicon. The sensor was fabricated using microelectromechanical system bulk-silicon technology, and it was validated using the finite element method. A precise data acquisition circuit with an accuracy of 20 μV was designed to obtain weak voltage signals. By calibration, the sensing system was shown to have a sensitivity of 17.29 mV/μm and 4.59 mV/μm in the axial and lateral directions, respectively; the nonlinearity in these directions was 0.8% and 1.0% full scale, respectively. A full range of 4.6 μm was achieved in the axial direction. Results of a resolution test indicated that the sensing system had a resolution of 5 nm in the axial direction and 10 nm in the lateral direction. PMID:25360581

Shot-noise limited throughput of soft x-ray ptychography for nanometrology applications

NASA Astrophysics Data System (ADS)

Koek, Wouter; Florijn, Bastiaan; Bäumer, Stefan; Kruidhof, Rik; Sadeghian, Hamed

2018-03-01

Due to its potential for high resolution and three-dimensional imaging, soft x-ray ptychography has received interest for nanometrology applications. We have analyzed the measurement time per unit area when using soft x-ray ptychography for various nanometrology applications including mask inspection and wafer inspection, and are thus able to predict (order of magnitude) throughput figures. Here we show that for a typical measurement system, using a typical sampling strategy, and when aiming for 10-15 nm resolution, it is expected that a wafer-based topology (2.5D) measurement takes approximately 4 minutes per μm2 , and a full three-dimensional measurement takes roughly 6 hours per μm2 . Due to their much higher reflectivity EUV masks can be measured considerably faster; a measurement speed of 0.1 seconds per μm2 is expected. However, such speeds do not allow for full wafer or mask inspection at industrially relevant throughput.

Full Counting Statistics for Interacting Fermions with Determinantal Quantum Monte Carlo Simulations.

PubMed

Humeniuk, Stephan; Büchler, Hans Peter

2017-12-08

We present a method for computing the full probability distribution function of quadratic observables such as particle number or magnetization for the Fermi-Hubbard model within the framework of determinantal quantum Monte Carlo calculations. Especially in cold atom experiments with single-site resolution, such a full counting statistics can be obtained from repeated projective measurements. We demonstrate that the full counting statistics can provide important information on the size of preformed pairs. Furthermore, we compute the full counting statistics of the staggered magnetization in the repulsive Hubbard model at half filling and find excellent agreement with recent experimental results. We show that current experiments are capable of probing the difference between the Hubbard model and the limiting Heisenberg model.

PCR Amplification Strategies towards full-length HIV-1 Genome sequencing.

PubMed

Liu, Chao Chun; Ji, Hezhao

2018-06-26

The advent of next generation sequencing has enabled greater resolution of viral diversity and improved feasibility of full viral genome sequencing allowing routine HIV-1 full genome sequencing in both research and diagnostic settings. Regardless of the sequencing platform selected, successful PCR amplification of the HIV-1 genome is essential for sequencing template preparation. As such, full HIV-1 genome amplification is a crucial step in dictating the successful and reliable sequencing downstream. Here we reviewed existing PCR protocols leading to HIV-1 full genome sequencing. In addition to the discussion on basic considerations on relevant PCR design, the advantages as well as the pitfalls of published protocols were reviewed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A Multi-Resolution Mode CMOS Image Sensor with a Novel Two-Step Single-Slope ADC for Intelligent Surveillance Systems.

PubMed

Kim, Daehyeok; Song, Minkyu; Choe, Byeongseong; Kim, Soo Youn

2017-06-25

In this paper, we present a multi-resolution mode CMOS image sensor (CIS) for intelligent surveillance system (ISS) applications. A low column fixed-pattern noise (CFPN) comparator is proposed in 8-bit two-step single-slope analog-to-digital converter (TSSS ADC) for the CIS that supports normal, 1/2, 1/4, 1/8, 1/16, 1/32, and 1/64 mode of pixel resolution. We show that the scaled-resolution images enable CIS to reduce total power consumption while images hold steady without events. A prototype sensor of 176 × 144 pixels has been fabricated with a 0.18 μm 1-poly 4-metal CMOS process. The area of 4-shared 4T-active pixel sensor (APS) is 4.4 μm × 4.4 μm and the total chip size is 2.35 mm × 2.35 mm. The maximum power consumption is 10 mW (with full resolution) with supply voltages of 3.3 V (analog) and 1.8 V (digital) and 14 frame/s of frame rates.

Magnetoacoustic microscopic imaging of conductive objects and nanoparticles distribution

NASA Astrophysics Data System (ADS)

Liu, Siyu; Zhang, Ruochong; Luo, Yunqi; Zheng, Yuanjin

2017-09-01

Magnetoacoustic tomography has been demonstrated as a powerful and low-cost multi-wave imaging modality. However, due to limited spatial resolution and detection efficiency of magnetoacoustic signal, full potential of the magnetoacoustic imaging remains to be tapped. Here we report a high-resolution magnetoacoustic microscopy method, where magnetic stimulation is provided by a compact solenoid resonance coil connected with a matching network, and acoustic reception is realized by using a high-frequency focused ultrasound transducer. Scanning the magnetoacoustic microscopy system perpendicularly to the acoustic axis of the focused transducer would generate a two-dimensional microscopic image with acoustically determined lateral resolution. It is analyzed theoretically and demonstrated experimentally that magnetoacoustic generation in this microscopic system depends on the conductivity profile of conductive objects and localized distribution of superparamagnetic iron magnetic nanoparticles, based on two different but related implementations. The lateral resolution is characterized. Directional nature of magnetoacoustic vibration and imaging sensitivity for mapping magnetic nanoparticles are also discussed. The proposed microscopy system offers a high-resolution method that could potentially map intrinsic conductivity distribution in biological tissue and extraneous magnetic nanoparticles.

120nm resolution in thick samples with structured illumination and adaptive optics

NASA Astrophysics Data System (ADS)

Thomas, Benjamin; Sloan, Megan; Wolstenholme, Adrian J.; Kner, Peter

2014-03-01

μLinear Structured Illumination Microscopy (SIM) provides a two-fold increase over the diffraction limited resolution. SIM produces excellent images with 120nm resolution in tissue culture cells in two and three dimensions. For SIM to work correctly, the point spread function (PSF) and optical transfer function (OTF) must be known, and, ideally, should be unaberrated. When imaging through thick samples, aberrations will be introduced into the optical system which will reduce the peak intensity and increase the width of the PSF. This will lead to reduced resolution and artifacts in SIM images. Adaptive optics can be used to correct the optical wavefront restoring the PSF to its unaberrated state, and AO has been used in several types of fluorescence microscopy. We demonstrate that AO can be used with SIM to achieve 120nm resolution through 25m of tissue by imaging through the full thickness of an adult C. elegans roundworm. The aberrations can be corrected over a 25μm × 45μm field of view with one wavefront correction setting, demonstrating that AO can be used effectively with widefield superresolution techniques.

The Officer’s Handbook; A Soviet View

DTIC Science & Technology

1971-05-01

this is an organ of complex structure, incorporating the lens, retina, optic nerve , and occipital lobes of the cortex. By means of the eye we sense...who bears full responsibility tor all aspects of the life and activities of the subunit, unit, ship, formation, or establishment, for the state of...local Party organizations, maintaining, however, full independence of the system. (From a resolution of the X Congress of the RCP(b) on the military

Oil spill analysis by means of full polarimetric UAVSAR (L-band) and Radarsat-2 (C-band) products acquired during Deepwater Horizon Disaster

NASA Astrophysics Data System (ADS)

Latini, Daniele; Del Frate, Fabio; Jones, Cathleen E.

2014-10-01

SAR instruments with polarimetric capabilities, high resolution and short revisit time can provide powerful support in oil spill monitoring and different techniques of analysis have been developed for this purpose [1][2]. An oil film on the sea surface results in darker areas in SAR images, but careful interpretation is required because dark spots can also be caused by natural phenomena. In view of the very low backscatter from slicks, the Noise Equivalent Sigma Zero (NESZ) is a primary sensor parameter to be considered when using a sensor for slick analysis. Among the existing full polarimetric sensors, the high resolution and very low NESZ values of UAVSAR (L-band) and RADARSAT-2 (C-band) make them preferable for oil spill analysis compared to the last generation SAR instruments. The Deepwater Horizon disaster that occurred in the Gulf of Mexico in 2010 represents a unique and extensive test site where large amounts of SAR imagery and ground validation data are available. By applying the Cloude-Pottier decomposition method to full polarimetric UAVSAR (L-band) and RADARSAT-2 (C-band), it is possible to extract parameters that describe the scattering mechanism of the target. By comparing quasi-simultaneous acquisitions and exploiting the different penetration capabilities of the sensors, we investigate the potential of full polarimetric SAR to discriminate oil on the sea surface from look-alike phenomena covering the full range of backscattering values down to those at the instrument noise floor.

Multimodal full-field optical coherence tomography on biological tissue: toward all optical digital pathology

NASA Astrophysics Data System (ADS)

Harms, F.; Dalimier, E.; Vermeulen, P.; Fragola, A.; Boccara, A. C.

2012-03-01

Optical Coherence Tomography (OCT) is an efficient technique for in-depth optical biopsy of biological tissues, relying on interferometric selection of ballistic photons. Full-Field Optical Coherence Tomography (FF-OCT) is an alternative approach to Fourier-domain OCT (spectral or swept-source), allowing parallel acquisition of en-face optical sections. Using medium numerical aperture objective, it is possible to reach an isotropic resolution of about 1x1x1 ìm. After stitching a grid of acquired images, FF-OCT gives access to the architecture of the tissue, for both macroscopic and microscopic structures, in a non-invasive process, which makes the technique particularly suitable for applications in pathology. Here we report a multimodal approach to FF-OCT, combining two Full-Field techniques for collecting a backscattered endogeneous OCT image and a fluorescence exogeneous image in parallel. Considering pathological diagnosis of cancer, visualization of cell nuclei is of paramount importance. OCT images, even for the highest resolution, usually fail to identify individual nuclei due to the nature of the optical contrast used. We have built a multimodal optical microscope based on the combination of FF-OCT and Structured Illumination Microscopy (SIM). We used x30 immersion objectives, with a numerical aperture of 1.05, allowing for sub-micron transverse resolution. Fluorescent staining of nuclei was obtained using specific fluorescent dyes such as acridine orange. We present multimodal images of healthy and pathological skin tissue at various scales. This instrumental development paves the way for improvements of standard pathology procedures, as a faster, non sacrificial, operator independent digital optical method compared to frozen sections.

CASL VMA Milestone Report FY16 (L3:VMA.VUQ.P13.08): Westinghouse Mixing with STAR-CCM+

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilkey, Lindsay Noelle

2016-09-30

STAR-CCM+ (STAR) is a high-resolution computational fluid dynamics (CFD) code developed by CD-adapco. STAR includes validated physics models and a full suite of turbulence models including ones from the k-ε and k-ω families. STAR is currently being developed to be able to do two phase flows, but the current focus of the software is single phase flow. STAR can use imported meshes or use the built in meshing software to create computation domains for CFD. Since the solvers generally require a fine mesh for good computational results, the meshes used with STAR tend to number in the millions of cells,more » with that number growing with simulation and geometry complexity. The time required to model the flow of a full 5x5 Mixing Vane Grid Assembly (5x5MVG) in the current STAR configuration is on the order of hours, and can be very computationally expensive. COBRA-TF (CTF) is a low-resolution subchannel code that can be trained using high fidelity data from STAR. CTF does not have turbulence models and instead uses a turbulent mixing coefficient β. With a properly calibrated β, CTF can be used a low-computational cost alternative to expensive full CFD calculations performed with STAR. During the Hi2Lo work with CTF and STAR, STAR-CCM+ will be used to calibrate β and to provide high-resolution results that can be used in the place of and in addition to experimental results to reduce the uncertainty in the CTF results.« less

The survey on data format of Earth observation satellite data at JAXA.

NASA Astrophysics Data System (ADS)

Matsunaga, M.; Ikehata, Y.

2017-12-01

JAXA's earth observation satellite data are distributed by a portal web site for search and deliver called "G-Portal". Users can download the satellite data of GPM, TRMM, Aqua, ADEOS-II, ALOS (search only), ALOS-2 (search only), MOS-1, MOS-1b, ERS-1 and JERS-1 from G-Portal. However, these data formats are different by each satellite like HDF4, HDF5, NetCDF4, CEOS, etc., and which formats are not familiar to new data users. Although the HDF type self-describing format is very convenient and useful for big dataset information, old-type format product is not readable by open GIS tool nor apply OGC standard. Recently, the satellite data are widely used to be applied to the various needs such as disaster, earth resources, monitoring the global environment, Geographic Information System(GIS) and so on. In order to remove a barrier of using Earth Satellite data for new community users, JAXA has been providing the format-converted product like GeoTIFF or KMZ. In addition, JAXA provides format conversion tool itself. We investigate the trend of data format for data archive, data dissemination and data utilization, then we study how to improve the current product format for various application field users and make a recommendation for new product.

Hyperparameterization of soil moisture statistical models for North America with Ensemble Learning Models (Elm)

NASA Astrophysics Data System (ADS)

Steinberg, P. D.; Brener, G.; Duffy, D.; Nearing, G. S.; Pelissier, C.

2017-12-01

Hyperparameterization, of statistical models, i.e. automated model scoring and selection, such as evolutionary algorithms, grid searches, and randomized searches, can improve forecast model skill by reducing errors associated with model parameterization, model structure, and statistical properties of training data. Ensemble Learning Models (Elm), and the related Earthio package, provide a flexible interface for automating the selection of parameters and model structure for machine learning models common in climate science and land cover classification, offering convenient tools for loading NetCDF, HDF, Grib, or GeoTiff files, decomposition methods like PCA and manifold learning, and parallel training and prediction with unsupervised and supervised classification, clustering, and regression estimators. Continuum Analytics is using Elm to experiment with statistical soil moisture forecasting based on meteorological forcing data from NASA's North American Land Data Assimilation System (NLDAS). There Elm is using the NSGA-2 multiobjective optimization algorithm for optimizing statistical preprocessing of forcing data to improve goodness-of-fit for statistical models (i.e. feature engineering). This presentation will discuss Elm and its components, including dask (distributed task scheduling), xarray (data structures for n-dimensional arrays), and scikit-learn (statistical preprocessing, clustering, classification, regression), and it will show how NSGA-2 is being used for automate selection of soil moisture forecast statistical models for North America.

Mosaic of Digital Raster Soviet Topographic Maps of Afghanistan

USGS Publications Warehouse

Chirico, Peter G.; Warner, Michael B.

2005-01-01

EXPLANATION The data contained in this publication include scanned, geographically referenced digital raster graphics (DRGs) of Soviet 1:200,000 - scale topographic map quadrangles. The original Afghanistan topographic map series at 1:200,000 scale, for the entire country, was published by the Soviet military between 1985 and 1991(MTDGS, 85-91). Hard copies of these original paper maps were scanned using a large format scanner, reprojected into Geographic Coordinate System (GCS) coordinates, and then clipped to remove the map collars to create a seamless, topographic map base for the entire country. An index of all available topographic map sheets is displayed here: Index_Geo_DD.pdf. This publication also includes the originial topographic map quadrangles projected in Universal Transverse Mercator (UTM) projection. The country of Afghanistan spans three UTM Zones: Zone 41, Zone 42, and Zone 43. Maps are stored as GeoTIFFs in their respective UTM zone projection. Indexes of all available topographic map sheets in their respective UTM zone are displayed here: Index_UTM_Z41.pdf, Index_UTM_Z42.pdf, Index_UTM_Z43.pdf. An Adobe Acrobat PDF file of the U.S. Department of the Army's Technical Manual 30-548, is available (U.S. Army, 1958). This document has been translated into English for assistance in reading Soviet topographic map symbols.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillion, D.

This code enables one to display, take line-outs on, and perform various transformations on an image created by an array of integer*2 data. Uncompressed eight-bit TIFF files created on either the Macintosh or the IBM PC may also be read in and converted to a 16 bit signed integer image. This code is designed to handle all the formates used for PDS (photo-densitometer) files at the Lawrence Livermore National Laboratory. These formats are all explained by the application code. The image may be zoomed infinitely and the gray scale mapping can be easily changed. Line-outs may be horizontal or verticalmore » with arbitrary width, angled with arbitrary end points, or taken along any path. This code is usually used to examine spectrograph data. Spectral lines may be identified and a polynomial fit from position to wavelength may be found. The image array can be remapped so that the pixels all have the same change of lambda width. It is not necessary to do this, however. Lineouts may be printed, saved as Cricket tab-delimited files, or saved as PICT2 files. The plots may be linear, semilog, or logarithmic with nice values and proper scientific notation. Typically, spectral lines are curved. By identifying points on these lines and fitting their shapes by polyn.« less

The MODIS reprojection tool

USGS Publications Warehouse

Dwyer, John L.; Schmidt, Gail L.; Qu, J.J.; Gao, W.; Kafatos, M.; Murphy , R.E.; Salomonson, V.V.

2006-01-01

The MODIS Reprojection Tool (MRT) is designed to help individuals work with MODIS Level-2G, Level-3, and Level-4 land data products. These products are referenced to a global tiling scheme in which each tile is approximately 10° latitude by 10° longitude and non-overlapping (Fig. 9.1). If desired, the user may reproject only selected portions of the product (spatial or parameter subsetting). The software may also be used to convert MODIS products to file formats (generic binary and GeoTIFF) that are more readily compatible with existing software packages. The MODIS land products distributed by the Land Processes Distributed Active Archive Center (LP DAAC) are in the Hierarchical Data Format - Earth Observing System (HDF-EOS), developed by the National Center for Supercomputing Applications at the University of Illinois at Urbana Champaign for the NASA EOS Program. Each HDF-EOS file is comprised of one or more science data sets (SDSs) corresponding to geophysical or biophysical parameters. Metadata are embedded in the HDF file as well as contained in a .met file that is associated with each HDF-EOS file. The MRT supports 8-bit, 16-bit, and 32-bit integer data (both signed and unsigned), as well as 32-bit float data. The data type of the output is the same as the data type of each corresponding input SDS.

Raster Images of Geologic Maps of Middle Proterozoic Belt strata in parts of Benewah, Bonner, Kootenai and Shoshone Counties, Idaho and Lincoln, Mineral and Sanders Counties, Montana

USGS Publications Warehouse

Boleneus, David E.; Appelgate, Larry M.; Joseph, Nancy L.; Brandt, Theodore R.

2001-01-01

Geologic maps of the western part of the Belt Basin of western Montana and northern Idaho were converted into digital raster (TIFF image) format to facilitate their manipulation in geographic information systems. The 85-mile x 100-mile map area mostly contains rocks belonging to the lower and middle Belt Supergroup. The area is of interest as these Middle Proterozoic strata contain vein-type lead-zinc-silver deposits in the Coeur d?Alene Mining District in the St. Regis and Revett formations and strata-bound copper-silver deposits, such as the Troy mine, within the Revett Formation. The Prichard Formation is also prospective for strata-bound lead-zinc deposits because equivalent Belt strata in southern British Columbia, Canada host the Sullivan lead-zinc deposit. Map data converted to digital images include 13 geological maps at scales ranging from 1:48,000 to 1:12,000. Geologic map images produced from these maps by color scanning were registered to grid tick coverages in a Universal Transverse Mercator (North American Datum of 1927, zone 11) projection using ArcView Image Analysis. Geo-registering errors vary from 10 ft to 114 ft.

Leveraging Metadata to Create Interactive Images... Today!

NASA Astrophysics Data System (ADS)

Hurt, Robert L.; Squires, G. K.; Llamas, J.; Rosenthal, C.; Brinkworth, C.; Fay, J.

2011-01-01

The image gallery for NASA's Spitzer Space Telescope has been newly rebuilt to fully support the Astronomy Visualization Metadata (AVM) standard to create a new user experience both on the website and in other applications. We encapsulate all the key descriptive information for a public image, including color representations and astronomical and sky coordinates and make it accessible in a user-friendly form on the website, but also embed the same metadata within the image files themselves. Thus, images downloaded from the site will carry with them all their descriptive information. Real-world benefits include display of general metadata when such images are imported into image editing software (e.g. Photoshop) or image catalog software (e.g. iPhoto). More advanced support in Microsoft's WorldWide Telescope can open a tagged image after it has been downloaded and display it in its correct sky position, allowing comparison with observations from other observatories. An increasing number of software developers are implementing AVM support in applications and an online image archive for tagged images is under development at the Spitzer Science Center. Tagging images following the AVM offers ever-increasing benefits to public-friendly imagery in all its standard forms (JPEG, TIFF, PNG). The AVM standard is one part of the Virtual Astronomy Multimedia Project (VAMP); http://www.communicatingastronomy.org

Visualization of the Construction of Ancient Roman Buildings in Ostia Using Point Cloud Data

NASA Astrophysics Data System (ADS)

Hori, Y.; Ogawa, T.

2017-02-01

The implementation of laser scanning in the field of archaeology provides us with an entirely new dimension in research and surveying. It allows us to digitally recreate individual objects, or entire cities, using millions of three-dimensional points grouped together in what is referred to as "point clouds". In addition, the visualization of the point cloud data, which can be used in the final report by archaeologists and architects, should usually be produced as a JPG or TIFF file. Not only the visualization of point cloud data, but also re-examination of older data and new survey of the construction of Roman building applying remote-sensing technology for precise and detailed measurements afford new information that may lead to revising drawings of ancient buildings which had been adduced as evidence without any consideration of a degree of accuracy, and finally can provide new research of ancient buildings. We used laser scanners at fields because of its speed, comprehensive coverage, accuracy and flexibility of data manipulation. Therefore, we "skipped" many of post-processing and focused on the images created from the meta-data simply aligned using a tool which extended automatic feature-matching algorithm and a popular renderer that can provide graphic results.

Electroform replication used for multiple X-ray mirror production

NASA Technical Reports Server (NTRS)

Kowalski, M. P.; Ulmer, M. P.; Purcell, W. R., Jr.; Loughlin, J. E. A.

1984-01-01

The electroforming technique for producing X-ray mirrors is described, and results of X-ray tests performed on copies made from a simple conical mandrel are reported. The design of the mandrel is depicted and the total reflectivity as well as the full-wave half modulation resolution are shown as a function of energy. The reported work has improved on previous studies by providing smaller grazing angles, making measurements at higher energies, producing about four times as many replicas from one mandrel, and obtaining better angular resolution.

Electron attachment in F2 - Conclusive demonstration of nonresonant, s-wave coupling in the limit of zero electron energy

NASA Technical Reports Server (NTRS)

Chutjian, A.; Alajajian, S. H.

1987-01-01

Dissociative electron attachment to F2 has been observed in the energy range 0-140 meV, at a resolution of 6 meV (full width at half maximum). Results show conclusively a sharp, resolution-limited threshold behavior consistent with an s-wave cross section varying as sq rt of epsilon. Two accurate theoretical calculations predict only p-wave behavior varying as the sq rt of epsilon. Several nonadiabatic coupling effects leading to s-wave behavior are outlined.

Pressure-resisting cell for high-pressure, high-resolution nuclear magnetic resonance measurements at very high magnetic fields

NASA Astrophysics Data System (ADS)

Yamada, H.; Nishikawa, K.; Honda, M.; Shimura, T.; Akasaka, K.; Tabayashi, K.

2001-02-01

A pressure-resisting cell system has been developed for high-pressure high-resolution nuclear magnetic resonance (NMR) measurements up to a maximum pressure of 600 MPa. This cell system is capable of performing high-pressure experiments with any standard spectrometer, including modern high field NMR machines. A full description of the high-pressure NMR assembly mounted on a 750 MHz spectrometer is presented along with a detailed explanation of the procedure for preparing the pressure-resisting quartz and glass cells.

Spatial super-resolution of colored images by micro mirrors

NASA Astrophysics Data System (ADS)

Dahan, Daniel; Yaacobi, Ami; Pinsky, Ephraim; Zalevsky, Zeev

2018-06-01

In this paper, we present two methods of dealing with the geometric resolution limit of color imaging sensors. It is possible to overcome the pixel size limit by adding a digital micro-mirror device component on the intermediate image plane of an optical system, and adapting its pattern in a computerized manner before sampling each frame. The full RGB image can be reconstructed from the Bayer camera by building a dedicated optical design, or by adjusting the demosaicing process to the special format of the enhanced image.

Ultra-large field-of-view two-photon microscopy.

PubMed

Tsai, Philbert S; Mateo, Celine; Field, Jeffrey J; Schaffer, Chris B; Anderson, Matthew E; Kleinfeld, David

2015-06-01

We present a two-photon microscope that images the full extent of murine cortex with an objective-limited spatial resolution across an 8 mm by 10 mm field. The lateral resolution is approximately 1 µm and the maximum scan speed is 5 mm/ms. The scan pathway employs large diameter compound lenses to minimize aberrations and performs near theoretical limits. We demonstrate the special utility of the microscope by recording resting-state vasomotion across both hemispheres of the murine brain through a transcranial window and by imaging histological sections without the need to stitch.

Study of radar pulse compression for high resolution satellite altimetry

NASA Technical Reports Server (NTRS)

Dooley, R. P.; Nathanson, F. E.; Brooks, L. W.

1974-01-01

Pulse compression techniques are studied which are applicable to a satellite altimeter having a topographic resolution of + 10 cm. A systematic design procedure is used to determine the system parameters. The performance of an optimum, maximum likelihood processor is analysed, which provides the basis for modifying the standard split-gate tracker to achieve improved performance. Bandwidth considerations lead to the recommendation of a full deramp STRETCH pulse compression technique followed by an analog filter bank to separate range returns. The implementation of the recommended technique is examined.

Ministerial Resolution No. 435-88-ED creating within the Ministry of Education a Technical Committee for Women, the Family, and Population, 4 July 1988.

PubMed

1988-01-01

This Resolution creates a Technical Committee for Women, the Family, and Population within the Ministry of Education of Peru. The Committee has as its objective strengthening and enlarging the activities executed by the Minister of Education and ensuring the permanent revaluation and promotion of the family and women in the curriculum, educational texts, and training and learning activities, as well as in the role of the media in social communication. full text

Curiosity New Home

NASA Image and Video Library

2012-08-08

These are the first two full-resolution images of the Martian surface from the Navigation cameras on NASA Curiosity rover, which are located on the rover head or mast. The rim of Gale Crater can be seen in the distance beyond the pebbly ground.

A Basketball Court-Size Global Map of Mars for Education and Public Outreach

NASA Astrophysics Data System (ADS)

Hill, J. R.; Christensen, P. R.

2017-12-01

The Thermal Emission Imaging System (THEMIS) onboard the 2001 Mars Odyssey spacecraft has acquired over 220,000 infrared images of the Martian surface at a resolution of 100 m/pixel since the start of science operations in February 2002. A global map was previously developed by mosaicking together over 24,000 high-quality full-resolution THEMIS daytime infrared images. Although the resulting map has been extremely valuable for scientific and mission operations applications, it has been difficult to communicate this value to students, citizen scientists and the general public, since their interactions with the map have been limited to computer-based geographic information system (GIS) interfaces. We determined that, in order to better communicate the value and importance of mapping the entire Martian surface at this resolution, people need to be able to physically interact with the map and experience its full scale. Therefore, the THEMIS Day IR Global Mosaic with Colorized MOLA Elevation will be printed on a 45ft x 90ft vinyl mat, which will allow observers to walk across and physically experience the map at approximately full resolution (printed at 200 pixels per inch). The size of the map was chosen to fit on a standard high school basketball court, so that a large number of schools will have a sufficiently large indoor surface on which to display the map for education events. The vinyl material and printing process selected for the map have been proven to be wear-resistant in similar applications, as long as everyone who walks on the map wears socks or similarly soft foot coverings. In order to make transportation easier, the map will be printed in two 45ft x 45ft sections, which will be joined together at events to create the full 45ft x 90ft map. The final stages of the map production will take place in early fall 2017, followed by initial education events at Arizona State University and local schools to test the educational activities associated with the map. This project was partially inspired by the National Geographic Society's Giant Traveling Maps Program, was completed with the assistance of the Arizona Geographic Alliance, and was largely funded through the Arizona State University School of Earth and Space Exploration (SESE) Summer Exploration Graduate Fellowship program.

Dual energy CT with one full scan and a second sparse-view scan using structure preserving iterative reconstruction (SPIR)

NASA Astrophysics Data System (ADS)

Wang, Tonghe; Zhu, Lei

2016-09-01

Conventional dual-energy CT (DECT) reconstruction requires two full-size projection datasets with two different energy spectra. In this study, we propose an iterative algorithm to enable a new data acquisition scheme which requires one full scan and a second sparse-view scan for potential reduction in imaging dose and engineering cost of DECT. A bilateral filter is calculated as a similarity matrix from the first full-scan CT image to quantify the similarity between any two pixels, which is assumed unchanged on a second CT image since DECT scans are performed on the same object. The second CT image from reduced projections is reconstructed by an iterative algorithm which updates the image by minimizing the total variation of the difference between the image and its filtered image by the similarity matrix under data fidelity constraint. As the redundant structural information of the two CT images is contained in the similarity matrix for CT reconstruction, we refer to the algorithm as structure preserving iterative reconstruction (SPIR). The proposed method is evaluated on both digital and physical phantoms, and is compared with the filtered-backprojection (FBP) method, the conventional total-variation-regularization-based algorithm (TVR) and prior-image-constrained-compressed-sensing (PICCS). SPIR with a second 10-view scan reduces the image noise STD by a factor of one order of magnitude with same spatial resolution as full-view FBP image. SPIR substantially improves over TVR on the reconstruction accuracy of a 10-view scan by decreasing the reconstruction error from 6.18% to 1.33%, and outperforms TVR at 50 and 20-view scans on spatial resolution with a higher frequency at the modulation transfer function value of 10% by an average factor of 4. Compared with the 20-view scan PICCS result, the SPIR image has 7 times lower noise STD with similar spatial resolution. The electron density map obtained from the SPIR-based DECT images with a second 10-view scan has an average error of less than 1%.

Resolution analysis of marine seismic full waveform data by Bayesian inversion

NASA Astrophysics Data System (ADS)

Ray, A.; Sekar, A.; Hoversten, G. M.; Albertin, U.

2015-12-01

The Bayesian posterior density function (PDF) of earth models that fit full waveform seismic data convey information on the uncertainty with which the elastic model parameters are resolved. In this work, we apply the trans-dimensional reversible jump Markov Chain Monte Carlo method (RJ-MCMC) for the 1D inversion of noisy synthetic full-waveform seismic data in the frequency-wavenumber domain. While seismic full waveform inversion (FWI) is a powerful method for characterizing subsurface elastic parameters, the uncertainty in the inverted models has remained poorly known, if at all and is highly initial model dependent. The Bayesian method we use is trans-dimensional in that the number of model layers is not fixed, and flexible such that the layer boundaries are free to move around. The resulting parameterization does not require regularization to stabilize the inversion. Depth resolution is traded off with the number of layers, providing an estimate of uncertainty in elastic parameters (compressional and shear velocities Vp and Vs as well as density) with depth. We find that in the absence of additional constraints, Bayesian inversion can result in a wide range of posterior PDFs on Vp, Vs and density. These PDFs range from being clustered around the true model, to those that contain little resolution of any particular features other than those in the near surface, depending on the particular data and target geometry. We present results for a suite of different frequencies and offset ranges, examining the differences in the posterior model densities thus derived. Though these results are for a 1D earth, they are applicable to areas with simple, layered geology and provide valuable insight into the resolving capabilities of FWI, as well as highlight the challenges in solving a highly non-linear problem. The RJ-MCMC method also presents a tantalizing possibility for extension to 2D and 3D Bayesian inversion of full waveform seismic data in the future, as it objectively tackles the problem of model selection (i.e., the number of layers or cells for parameterization), which could ease the computational burden of evaluating forward models with many parameters.

Geophysical characterization of peatlands using crosshole GPR full-waveform inversion: Case study from a bog in northwestern Germany

NASA Astrophysics Data System (ADS)

Schmäck, J.; Klotzsche, A.; Van Der Kruk, J.; Vereecken, H.; Bechtold, M.

2017-12-01

The characterization of peatlands is of particular interest, since areas with peat soils represent global hotspots for the exchange of greenhouse gases. Their effect on global warming depends on several parameters, like mean annual water level and land use. Models of greenhouse gas emissions and carbon accumulation in peatlands can be improved by including small-scale soil properties that e.g. act as gas traps and periodically release gases to the atmosphere during ebullition events. Ground penetrating radar (GPR) is well suited to non- or minimal invasively characterize and improve our understanding of dynamic processes that take place in the critical zone. It uses high frequency electromagnetic waves to image and characterize the dielectric permittivity and electrical conductivity of the critical zone, which can be related to hydrogeological properties like porosity, soil water content, salinity and clay content. In the last decade, the full-waveform inversion of crosshole GPR data has proved to be a powerful tool to improve the image resolution compared to standard ray-based methods. This approach was successfully applied to several different aquifers and was able to provide decimeter-scale resolution images including small-scale high contrast layers that can be related to zones of high porosity, zones of preferential flow or clay lenses. The comparison to independently measured e.g. logging data proved the reliability of the method. Here, for the first time crosshole GPR full-waveform inversion is used to image three peatland plots with different land use that are part of the "Ahlen-Falkenberger Moor peat bog complex" in northwestern Germany. The full-waveform inversion of the acquired data returned higher resolution images than standard ray-based GPR methods, and, is able to improve our understanding of subsurface structures. The comparison of the different plots is expected to provide new insights into gas content and gas trapping structures across different land uses. Additionally, season-related changes of peatland soil properties are investigated. The crosshole GPR full-waveform inversion was successfully applied to several datasets and the results show the utility and credibility of GPR FWI to analyze peatland properties.

Does resolution of flow field observation influence apparent habitat use and energy expenditure in juvenile coho salmon?

USGS Publications Warehouse

Tullos, Desiree D.; Walter, Cara; Dunham, Jason B.

2016-01-01

This study investigated how the resolution of observation influences interpretation of how fish, juvenile Coho Salmon (Oncorhynchus kisutch), exploit the hydraulic environment in streams. Our objectives were to evaluate how spatial resolution of the flow field observation influenced: (1) the velocities considered to be representative of habitat units; (2) patterns of use of the hydraulic environment by fish; and (3) estimates of energy expenditure. We addressed these objectives using observations within a 1:1 scale physical model of a full-channel log jam in an outdoor experimental stream. Velocities were measured with Acoustic Doppler Velocimetry at a 10 cm grid spacing, whereas fish locations and tailbeat frequencies were documented over time using underwater videogrammetry. Results highlighted that resolution of observation did impact perceived habitat use and energy expenditure, as did the location of measurement within habitat units and the use of averaging to summarize velocities within a habitat unit. In this experiment, the range of velocities and energy expenditure estimates increased with coarsening resolution (grid spacing from 10 to 100 cm), reducing the likelihood of measuring the velocities locally experienced by fish. In addition, the coarser resolutions contributed to fish appearing to select velocities that were higher than what was measured at finer resolutions. These findings indicate the need for careful attention to and communication of resolution of observation in investigating the hydraulic environment and in determining the habitat needs and bioenergetics of aquatic biota.

Dual-resolution image reconstruction for region-of-interest CT scan

NASA Astrophysics Data System (ADS)

Jin, S. O.; Shin, K. Y.; Yoo, S. K.; Kim, J. G.; Kim, K. H.; Huh, Y.; Lee, S. Y.; Kwon, O.-K.

2014-07-01

In ordinary CT scan, so called full field-of-view (FFOV) scan, in which the x-ray beam span covers the whole section of the body, a large number of projections are necessary to reconstruct high resolution images. However, excessive x-ray dose is a great concern in FFOV scan. Region-of-interest (ROI) scan is a method to visualize the ROI in high resolution while reducing the x-ray dose. But, ROI scan suffers from bright-band artifacts which may hamper CT-number accuracy. In this study, we propose an image reconstruction method to eliminate the band artifacts in the ROI scan. In addition to the ROI scan with high sampling rate in the view direction, we get FFOV projection data with much lower sampling rate. Then, we reconstruct images in the compressed sensing (CS) framework with dual resolutions, that is, high resolution in the ROI and low resolution outside the ROI. For the dual-resolution image reconstruction, we implemented the dual-CS reconstruction algorithm in which data fidelity and total variation (TV) terms were enforced twice in the framework of adaptive steepest descent projection onto convex sets (ASD-POCS). The proposed method has remarkably reduced the bright-band artifacts at around the ROI boundary, and it has also effectively suppressed the streak artifacts over the entire image. We expect the proposed method can be greatly used for dual-resolution imaging with reducing the radiation dose, artifacts and scan time.

Multispectral multisensor image fusion using wavelet transforms

USGS Publications Warehouse

Lemeshewsky, George P.

1999-01-01

Fusion techniques can be applied to multispectral and higher spatial resolution panchromatic images to create a composite image that is easier to interpret than the individual images. Wavelet transform-based multisensor, multiresolution fusion (a type of band sharpening) was applied to Landsat thematic mapper (TM) multispectral and coregistered higher resolution SPOT panchromatic images. The objective was to obtain increased spatial resolution, false color composite products to support the interpretation of land cover types wherein the spectral characteristics of the imagery are preserved to provide the spectral clues needed for interpretation. Since the fusion process should not introduce artifacts, a shift invariant implementation of the discrete wavelet transform (SIDWT) was used. These results were compared with those using the shift variant, discrete wavelet transform (DWT). Overall, the process includes a hue, saturation, and value color space transform to minimize color changes, and a reported point-wise maximum selection rule to combine transform coefficients. The performance of fusion based on the SIDWT and DWT was evaluated with a simulated TM 30-m spatial resolution test image and a higher resolution reference. Simulated imagery was made by blurring higher resolution color-infrared photography with the TM sensors' point spread function. The SIDWT based technique produced imagery with fewer artifacts and lower error between fused images and the full resolution reference. Image examples with TM and SPOT 10-m panchromatic illustrate the reduction in artifacts due to the SIDWT based fusion.

Visible light optical coherence microscopy imaging of the mouse cortex with femtoliter volume resolution

NASA Astrophysics Data System (ADS)

Merkle, Conrad W.; Chong, Shau Poh; Kho, Aaron M.; Zhu, Jun; Kholiqov, Oybek; Dubra, Alfredo; Srinivasan, Vivek J.

2018-02-01

Most flying-spot Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM) systems use a symmetric confocal geometry, where the detection path retraces the illumination path starting from and ending with the spatial mode of a single mode optical fiber. Here, we describe a visible light OCM instrument that breaks this symmetry to improve transverse resolution without sacrificing collection efficiency in scattering tissue. This was achieved by overfilling a 0.3 numerical aperture (NA) water immersion objective on the illumination path, while maintaining a conventional Gaussian mode detection path (1/e2 intensity diameter 0.82 Airy disks), enabling 1.1 μm full-width at half-maximum (FWHM) transverse resolution. At the same time, a 0.9 μm FWHM axial resolution in tissue, achieved by a broadband visible light source, enabled femtoliter volume resolution. We characterized this instrument according to paraxial coherent microscopy theory, and then used it to image the meningeal layers, intravascular red blood cell-free layer, and myelinated axons in the mouse neocortex in vivo through the thinned skull. Finally, by introducing a 0.8 NA water immersion objective, we improved the lateral resolution to 0.44 μm FWHM, which provided a volumetric resolution of 0.2 fL, revealing cell bodies in cortical layer I of the mouse brain with OCM for the first time.

A 2D/3D hybrid integral imaging display by using fast switchable hexagonal liquid crystal lens array

NASA Astrophysics Data System (ADS)

Lee, Hsin-Hsueh; Huang, Ping-Ju; Wu, Jui-Yi; Hsieh, Po-Yuan; Huang, Yi-Pai

2017-05-01

The paper proposes a new display which could switch 2D and 3D images on a monitor, and we call it as Hybrid Display. In 3D display technologies, the reduction of image resolution is still an important issue. The more angle information offer to the observer, the less spatial resolution would offer to image resolution because of the fixed panel resolution. Take it for example, in the integral photography system, the part of image without depth, like background, will reduce its resolution by transform from 2D to 3D image. Therefore, we proposed a method by using liquid crystal component to quickly switch the 2D image and 3D image. Meanwhile, the 2D image is set as a background to compensate the resolution.. In the experiment, hexagonal liquid crystal lens array would be used to take the place of fixed lens array. Moreover, in order to increase lens power of the hexagonal LC lens array, we applied high resistance (Hi-R) layer structure on the electrode. Hi-R layer would make the gradient electric field and affect the lens profile. Also, we use panel with 801 PPI to display the integral image in our system. Hence, the consequence of full resolution 2D background with the 3D depth object forms the Hybrid Display.

Estimation of Spatial Trends in LAI in Heterogeneous Semi-arid Ecosystems using Full Waveform Lidar

NASA Astrophysics Data System (ADS)

Glenn, N. F.; Ilangakoon, N.; Spaete, L.; Dashti, H.

2017-12-01

Leaf area index (LAI) is a key structural trait that is defined by the plant functional type (PFT) and controlled by prevailing climate- and human-driven ecosystem stresses. Estimates of LAI using remote sensing techniques are limited by the uncertainties of vegetation inter and intra-gap fraction estimates; this is especially the case in sparse, low stature vegetated ecosystems. Small footprint full waveform lidar digitizes the total amount of return energy with the direction information as a near continuous waveform at a high vertical resolution (1 ns). Thus waveform lidar provides additional data matrices to capture vegetation gaps as well as PFTs that can be used to constrain the uncertainties of LAI estimates. In this study, we calculated a radiometrically calibrated full waveform parameter called backscatter cross section, along with other data matrices from the waveform to estimate vegetation gaps across plots (10 m x 10 m) in a semi-arid ecosystem in the western US. The LAI was then estimated using empirical relationships with directional gap fraction. Full waveform-derived gap fraction based LAI showed a high correlation with field observed shrub LAI (R2 = 0.66, RMSE = 0.24) compared to discrete return lidar based LAI (R2 = 0.01, RMSE = 0.5). The data matrices derived from full waveform lidar classified a number of deciduous and evergreen tree species, shrub species, and bare ground with an overall accuracy of 89% at 10 m. A similar analysis was performed at 1m with overall accuracy of 80%. The next step is to use these relationships to map the PFTs LAI at 10 m spatial scale across the larger study regions. The results show the exciting potential of full waveform lidar to identify plant functional types and LAI in low-stature vegetation dominated semi-arid ecosystems, an ecosystem in which many other remote sensing techniques fail. These results can be used to assess ecosystem state, habitat suitability as well as to constrain model uncertainties in vegetation dynamic models with a combination of other remote sensing techniques. Multi-spatial resolution (1 m and 10 m) studies provide basic information on the applicability and detection thresholds of future global satellite sensors designed at coarser spatial resolutions (e.g. GEDI, ICESat-2) in semi-arid ecosystems.

LANDSAT 4 investigations of Thematic Mapper and multispectral scanner applications. [Death Valley, California; Silver Bell Copper Mine, Arizona, and Dulles Airport near Washington, D.C.

NASA Technical Reports Server (NTRS)

Lauer, D. T. (Principal Investigator)

1984-01-01

The optimum index factor package was used to choose TM band for color compositing. Processing techniques were also used on TM data over several sites to: (1) reduce the amount of data that needs to be processed and analyzed by using statistical methods or by combining full-resolution products with spatially compressed products; (2) digitally process small subareas to improve the visual appearance of large-scale products or to merge different-resolution image data; and (3) evaluate and compare the information content of the different three-band combinations that can be made using the TM data. Results indicate that for some applications the added spectral information over MSS is even more important than the TM's increased spatial resolution.

Integrated optics to improve resolution on multiple configuration

NASA Astrophysics Data System (ADS)

Liu, Hua; Ding, Quanxin; Guo, Chunjie; Zhou, Liwei

2015-04-01

Inspired to in order to reveal the structure to improve imaging resolution, further technical requirement is proposed in some areas of the function and influence on the development of multiple configuration. To breakthrough diffraction limit, smart structures are recommended as the most efficient and economical method, while by used to improve the system performance, especially on signal to noise ratio and resolution. Integrated optics were considered in the selection, with which typical multiple configuration, by use the method of simulation experiment. Methodology can change traditional design concept and to develop the application space. Our calculations using multiple matrix transfer method, also the correlative algorithm and full calculations, show the expected beam shaping through system and, in particular, the experimental results will support our argument, which will be reported in the presentation.

Scintillating fibres coupled to silicon photomultiplier prototypes for fast beam monitoring and thin timing detectors

NASA Astrophysics Data System (ADS)

Papa, A.; Kettle, P.-R.; Ripiccini, E.; Rutar, G.

2016-07-01

Several scintillating fibre prototypes (single- and double-layers) made of 250 μm multi-clad square fibres coupled to silicon photomultiplier have been studied using electrons, positrons and muons at different energies. Current measurements show promising results: already for a single fibre layer and minimum ionizing particles we obtain a detection efficiency ≥ 95 % (mean collected light/fibre ≈ 8 phe), a timing resolution of 550 ps/fibre and a foreseen spatial resolution < 100 μm, based on the achieved negligible optical cross-talk between fibres (< 1 %). We will also discuss the performances of a double-layer staggered prototype configuration, for which a full detection efficiency (≥ 99 %) has been measured together with a timing resolution of ≈ 400 ps for double hit events.

Slitless Solar Spectroscopy

NASA Technical Reports Server (NTRS)

Davila, Joseph M.; Jones, Sahela

2011-01-01

Spectrographs have traditionally suffered from the inability to obtain line intensities, widths, and Doppler shifts over large spatial regions of the Sun quickly because of the narrow instantaneous field of view. This has limited the spectroscopic analysis of rapidly varying solar features like, flares, CME eruptions, coronal jets, and reconnection regions. Imagers have provided high time resolution images of the full Sun with limited spectral resolution. In this paper we present recent advances in deconvolving spectrally dispersed images obtained through broad slits. We use this new theoretical formulation to examine the effectiveness of various potential observing scenarios, spatial and spectral resolutions, signal to noise ratio, and other instrument characteristics. This information will lay the foundation for a new generation of spectral imagers optimized for slitless spectral operation, while retaining the ability to obtain spectral information in transient solar events.

Further advances in autostereoscopic technology at Dimension Technologies Inc.

NASA Astrophysics Data System (ADS)

Eichenlaub, Jesse B.

1992-06-01

Dimension Technologies is currently one of three companies offering autostereoscopic displays for sale and one of several which are actively pursuing advances to the technology. We have devised a new autostereoscopic imaging technique which possesses several advantages over previously explored methods. We are currently manufacturing autostereoscopic displays based on this technology, as well as vigorously pursuing research and development toward more advanced displays. During the past year, DTI has made major strides in advancing its LCD based autostereoscopic display technology. DTI has developed a color product -- a stand alone 640 X 480 flat panel LCD based 3-D display capable of accepting input from IBM PC and Apple MAC computers or TV cameras, and capable of changing from 3-D mode to 2-D mode with the flip of a switch. DTI is working on development of a prototype second generation color product that will provide autostereoscopic 3-D while allowing each eye to see the full resolution of the liquid crystal display. And development is also underway on a proof-of-concept display which produces hologram-like look-around images visible from a wide viewing angle, again while allowing the observer to see the full resolution of the display from all locations. Development of a high resolution prototype display of this type has begun.

Structure of the toxic core of α-synuclein from invisible crystals

DOE PAGES

Rodriguez, Jose A.; Ivanova, Magdalena I.; Sawaya, Michael R.; ...

2015-09-09

We report that the protein α-synuclein is the main component of Lewy bodies, the neuron-associated aggregates seen in Parkinson disease and other neurodegenerative pathologies. An 11-residue segment, which we term NACore, appears to be responsible for amyloid formation and cytotoxicity of human α-synuclein. Here we describe crystals of NACore that have dimensions smaller than the wavelength of visible light and thus are invisible by optical microscopy. As the crystals are thousands of times too small for structure determination by synchrotron X-ray diffraction, we use micro-electron diffraction to determine the structure at atomic resolution. The 1.4 Å resolution structure demonstrates thatmore » this method can determine previously unknown protein structures and here yields, to our knowledge, the highest resolution achieved by any cryo-electron microscopy method to date. The structure exhibits protofibrils built of pairs of face-to-face β-sheets. X-ray fibre diffraction patterns show the similarity of NACore to toxic fibrils of full-length α-synuclein. Finally, the NACore structure, together with that of a second segment, inspires a model for most of the ordered portion of the toxic, full-length α-synuclein fibril, presenting opportunities for the design of inhibitors of α-synuclein fibrils.« less

Study of the Effect of Temporal Sampling Frequency on DSCOVR Observations Using the GEOS-5 Nature Run Results (Part I): Earths Radiation Budget

NASA Technical Reports Server (NTRS)

Holdaway, Daniel; Yang, Yuekui

2016-01-01

Satellites always sample the Earth-atmosphere system in a finite temporal resolution. This study investigates the effect of sampling frequency on the satellite-derived Earth radiation budget, with the Deep Space Climate Observatory (DSCOVR) as an example. The output from NASA's Goddard Earth Observing System Version 5 (GEOS-5) Nature Run is used as the truth. The Nature Run is a high spatial and temporal resolution atmospheric simulation spanning a two-year period. The effect of temporal resolution on potential DSCOVR observations is assessed by sampling the full Nature Run data with 1-h to 24-h frequencies. The uncertainty associated with a given sampling frequency is measured by computing means over daily, monthly, seasonal and annual intervals and determining the spread across different possible starting points. The skill with which a particular sampling frequency captures the structure of the full time series is measured using correlations and normalized errors. Results show that higher sampling frequency gives more information and less uncertainty in the derived radiation budget. A sampling frequency coarser than every 4 h results in significant error. Correlations between true and sampled time series also decrease more rapidly for a sampling frequency less than 4 h.

Areosynchronous weather imager

NASA Astrophysics Data System (ADS)

Puschell, Jeffery J.; Lock, Robert

2016-09-01

Mars is characterized by rapidly changing, poorly understood weather that is a concern for future human missions. Future Areosynchronous Mars Orbit (AMO) communication satellites offer possible platforms for Mars weather imagers similar to the geosynchronous Earth orbit (GEO) weather imagers that have been observing Earth since 1966. This paper describes an AReosynchronous Environmental Suite (ARES) that includes two imagers: one with two emissive infrared bands (10.8 μm and 12.0 μm) at 4 km resolution and the other with three VNIR bands (500 nm, 700 nm, 900 nm) at 1 km resolution. ARES stares at Mars and provides full disk coverage as fast as every 40 sec in the VNIR bands and every 2 min in the emissive bands with good sensitivity (SNR 200 in the VNIR for typical radiances and NEDT 0.2K at 180 K scene temperature in the emissive infrared). ARES size, mass, power and data rate characteristics are compatible with expectations for hosted payloads onboard future AMO communication satellites. Nevertheless, more work is needed to optimize ARES for future missions, especially in terms of trades between data rate, full disk coverage rate, sensitivity, number of spectral bands and spatial resolution and in study of approaches for maintaining accurate line of sight knowledge during data collection.

Combined magnetic resonance imaging approach for the assessment of in vivo knee joint kinematics under full weight-bearing conditions.

PubMed

Al Hares, Ghaith; Eschweiler, Jörg; Radermacher, Klaus

2015-06-01

The development of detailed and specific knowledge on the biomechanical behavior of loaded knee structures has received increased attention in recent years. Stress magnetic resonance imaging techniques have been introduced in previous work to study knee kinematics under load conditions. Previous studies captured the knee movement either in atypical loading supine positions, or in upright positions with help of inclined supporting backrests being insufficient for movement capture under full-body weight-bearing conditions. In this work, we used a combined magnetic resonance imaging approach for measurement and assessment in knee kinematics under full-body weight-bearing in single legged stance. The proposed method is based on registration of high-resolution static magnetic resonance imaging data acquired in supine position with low-resolution data, quasi-static upright-magnetic resonance imaging data acquired in loaded positions for different degrees of knee flexion. The proposed method was applied for the measurement of tibiofemoral kinematics in 10 healthy volunteers. The combined magnetic resonance imaging approach allows the non-invasive measurement of knee kinematics in single legged stance and under physiological loading conditions. We believe that this method can provide enhanced understanding of the loaded knee kinematics. © IMechE 2015.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assenberg, René; Delmas, Olivier; Graham, Stephen C.

The expression, purification and crystallization of the full-length matrix protein from three lyssaviruses is described. The matrix (M) proteins of lyssaviruses (family Rhabdoviridae) are crucial to viral morphogenesis as well as in modulating replication and transcription of the viral genome. To date, no high-resolution structural information has been obtained for full-length rhabdovirus M. Here, the cloning, expression and purification of the matrix proteins from three lyssaviruses, Lagos bat virus (LAG), Mokola virus and Thailand dog virus, are described. Crystals have been obtained for the full-length M protein from Lagos bat virus (LAG M). Successful crystallization depended on a number ofmore » factors, in particular the addition of an N-terminal SUMO fusion tag to increase protein solubility. Diffraction data have been recorded from crystals of native and selenomethionine-labelled LAG M to 2.75 and 3.0 Å resolution, respectively. Preliminary analysis indicates that these crystals belong to space group P6{sub 1}22 or P6{sub 5}22, with unit-cell parameters a = b = 56.9–57.2, c = 187.9–188.6 Å, consistent with the presence of one molecule per asymmetric unit, and structure determination is currently in progress.« less

Resolution of VTI anisotropy with elastic full-waveform inversion: theory and basic numerical examples

NASA Astrophysics Data System (ADS)

Podgornova, O.; Leaney, S.; Liang, L.

2018-07-01

Extracting medium properties from seismic data faces some limitations due to the finite frequency content of the data and restricted spatial positions of the sources and receivers. Some distributions of the medium properties make low impact on the data (including none). If these properties are used as the inversion parameters, then the inverse problem becomes overparametrized, leading to ambiguous results. We present an analysis of multiparameter resolution for the linearized inverse problem in the framework of elastic full-waveform inversion. We show that the spatial and multiparameter sensitivities are intertwined and non-sensitive properties are spatial distributions of some non-trivial combinations of the conventional elastic parameters. The analysis accounts for the Hessian information and frequency content of the data; it is semi-analytical (in some scenarios analytical), easy to interpret and enhances results of the widely used radiation pattern analysis. Single-type scattering is shown to have limited sensitivity, even for full-aperture data. Finite-frequency data lose multiparameter sensitivity at smooth and fine spatial scales. Also, we establish ways to quantify a spatial-multiparameter coupling and demonstrate that the theoretical predictions agree well with the numerical results.

5 CFR 2610.307 - Further proceedings.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 2610.307 Administrative Personnel OFFICE OF GOVERNMENT ETHICS ORGANIZATION AND PROCEDURES... written submissions or, as to issues other than substantial justification (such as the applicant's... further proceedings shall be held only when necessary for full and fair resolution of the issues arising...

Venus - Lakshmi Planum

NASA Image and Video Library

1996-03-07

This image is a full-resolution mosaic of several images from NASA Magellan spacecraft. The radar smooth region in the northern part of the image is Lakshmi Planum, a high plateau region above the mean planetary radius. http://photojournal.jpl.nasa.gov/catalog/PIA00240

Globally Gridded Satellite observations for climate studies

USGS Publications Warehouse

Knapp, K.R.; Ansari, S.; Bain, C.L.; Bourassa, M.A.; Dickinson, M.J.; Funk, Chris; Helms, C.N.; Hennon, C.C.; Holmes, C.D.; Huffman, G.J.; Kossin, J.P.; Lee, H.-T.; Loew, A.; Magnusdottir, G.

2011-01-01

Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them that no central archive of geostationary data for all international satellites exists, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multisatellite climate studies. The International Satellite Cloud Climatology Project (ISCCP) set the stage for overcoming these issues by archiving a subset of the full-resolution geostationary data at ~10-km resolution at 3-hourly intervals since 1983. Recent efforts at NOAA's National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in Network Common Data Format (netCDF) using standards that permit a wide variety of tools and libraries to process the data quickly and easily. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

a New High-Resolution Elevation Model of Greenland Derived from Tandem-X

NASA Astrophysics Data System (ADS)

Wessel, B.; Bertram, A.; Gruber, A.; Bemm, S.; Dech, S.

2016-06-01

In this paper we present for the first time the new digital elevation model (DEM) for Greenland produced by the TanDEM-X (TerraSAR add-on for digital elevation measurement) mission. The new, full coverage DEM of Greenland has a resolution of 0.4 arc seconds corresponding to 12 m. It is composed of more than 7.000 interferometric synthetic aperture radar (InSAR) DEM scenes. X-Band SAR penetrates the snow and ice pack by several meters depending on the structures within the snow, the acquisition parameters, and the dielectricity constant of the medium. Hence, the resulting SAR measurements do not represent the surface but the elevation of the mean phase center of the backscattered signal. Special adaptations on the nominal TanDEM-X DEM generation are conducted to maintain these characteristics and not to raise or even deform the DEM to surface reference data. For the block adjustment, only on the outer coastal regions ICESat (Ice, Cloud, and land Elevation Satellite) elevations as ground control points (GCPs) are used where mostly rock and surface scattering predominates. Comparisons with ICESat data and snow facies are performed. In the inner ice and snow pack, the final X-Band InSAR DEM of Greenland lies up to 10 m below the ICESat measurements. At the outer coastal regions it corresponds well with the GCPs. The resulting DEM is outstanding due to its resolution, accuracy and full coverage. It provides a high resolution dataset as basis for research on climate change in the arctic.

Compact full-motion video hyperspectral cameras: development, image processing, and applications

NASA Astrophysics Data System (ADS)

Kanaev, A. V.

2015-10-01

Emergence of spectral pixel-level color filters has enabled development of hyper-spectral Full Motion Video (FMV) sensors operating in visible (EO) and infrared (IR) wavelengths. The new class of hyper-spectral cameras opens broad possibilities of its utilization for military and industry purposes. Indeed, such cameras are able to classify materials as well as detect and track spectral signatures continuously in real time while simultaneously providing an operator the benefit of enhanced-discrimination-color video. Supporting these extensive capabilities requires significant computational processing of the collected spectral data. In general, two processing streams are envisioned for mosaic array cameras. The first is spectral computation that provides essential spectral content analysis e.g. detection or classification. The second is presentation of the video to an operator that can offer the best display of the content depending on the performed task e.g. providing spatial resolution enhancement or color coding of the spectral analysis. These processing streams can be executed in parallel or they can utilize each other's results. The spectral analysis algorithms have been developed extensively, however demosaicking of more than three equally-sampled spectral bands has been explored scarcely. We present unique approach to demosaicking based on multi-band super-resolution and show the trade-off between spatial resolution and spectral content. Using imagery collected with developed 9-band SWIR camera we demonstrate several of its concepts of operation including detection and tracking. We also compare the demosaicking results to the results of multi-frame super-resolution as well as to the combined multi-frame and multiband processing.

Globally Gridded Satellite (GridSat) Observations for Climate Studies

NASA Technical Reports Server (NTRS)

Knapp, Kenneth R.; Ansari, Steve; Bain, Caroline L.; Bourassa, Mark A.; Dickinson, Michael J.; Funk, Chris; Helms, Chip N.; Hennon, Christopher C.; Holmes, Christopher D.; Huffman, George J.;

Conception and realization of a semiconductor based 240 GHz full 3D MIMO imaging system

NASA Astrophysics Data System (ADS)

Weisenstein, Christian; Kahl, Matthias; Friederich, Fabian; Haring Bolívar, Peter

2017-02-01

Multiple-input multiple-output (MIMO) imaging systems in the terahertz frequency range have a high potential in the field of non-destructive testing (NDT). With such systems it is possible to detect defects in composite materials, for example cracks or delaminations in fiber composites. To investigate mass-produced products it is necessary to study the objects in close to real-time on a conveyor without affecting the production cycle time. In this work we present the conception and realization of a 3D MIMO imaging system for in-line investigation of composite materials and structures. To achieve a lateral resolution of 1 mm, in order to detect such small defects in composite materials with a moderate number of elements, precise sensor design is crucial. In our approach we use the effective aperture concept. The designed sparse array consists of 32 transmitters and 30 receivers based on planar semiconductor components. High range resolution is achieved by an operating frequency between 220 GHz and 260 GHz in a stepped frequency continuous wave (SFCW) setup. A matched filter approach is used to simulate the reconstructed 3D image through the array. This allows the evaluation of the designed array geometry in regard of resolution and side lobe level. In contrast to earlier demonstrations, in which synthetic reconstruction is only performed in a 2D plane, an optics-free full 3D recon- struction has been implemented in our concept. Based on this simulation we designed an array geometry that enables to resolve objects with a resolution smaller than 1mm and moderate side lobe level.

Radiometric infrared focal plane array imaging system for thermographic applications

NASA Technical Reports Server (NTRS)

Esposito, B. J.; Mccafferty, N.; Brown, R.; Tower, J. R.; Kosonocky, W. F.

1992-01-01

This document describes research performed under the Radiometric Infrared Focal Plane Array Imaging System for Thermographic Applications contract. This research investigated the feasibility of using platinum silicide (PtSi) Schottky-barrier infrared focal plane arrays (IR FPAs) for NASA Langley's specific radiometric thermal imaging requirements. The initial goal of this design was to develop a high spatial resolution radiometer with an NETD of 1 percent of the temperature reading over the range of 0 to 250 C. The proposed camera design developed during this study and described in this report provides: (1) high spatial resolution (full-TV resolution); (2) high thermal dynamic range (0 to 250 C); (3) the ability to image rapid, large thermal transients utilizing electronic exposure control (commandable dynamic range of 2,500,000:1 with exposure control latency of 33 ms); (4) high uniformity (0.5 percent nonuniformity after correction); and (5) high thermal resolution (0.1 C at 25 C background and 0.5 C at 250 C background).

Radiometric infrared focal plane array imaging system for thermographic applications

NASA Astrophysics Data System (ADS)

Esposito, B. J.; McCafferty, N.; Brown, R.; Tower, J. R.; Kosonocky, W. F.

1992-11-01

This document describes research performed under the Radiometric Infrared Focal Plane Array Imaging System for Thermographic Applications contract. This research investigated the feasibility of using platinum silicide (PtSi) Schottky-barrier infrared focal plane arrays (IR FPAs) for NASA Langley's specific radiometric thermal imaging requirements. The initial goal of this design was to develop a high spatial resolution radiometer with an NETD of 1 percent of the temperature reading over the range of 0 to 250 C. The proposed camera design developed during this study and described in this report provides: (1) high spatial resolution (full-TV resolution); (2) high thermal dynamic range (0 to 250 C); (3) the ability to image rapid, large thermal transients utilizing electronic exposure control (commandable dynamic range of 2,500,000:1 with exposure control latency of 33 ms); (4) high uniformity (0.5 percent nonuniformity after correction); and (5) high thermal resolution (0.1 C at 25 C background and 0.5 C at 250 C background).

Three-dimensional nanometre localization of nanoparticles to enhance super-resolution microscopy

NASA Astrophysics Data System (ADS)

Bon, Pierre; Bourg, Nicolas; Lécart, Sandrine; Monneret, Serge; Fort, Emmanuel; Wenger, Jérôme; Lévêque-Fort, Sandrine

2015-07-01

Meeting the nanometre resolution promised by super-resolution microscopy techniques (pointillist: PALM, STORM, scanning: STED) requires stabilizing the sample drifts in real time during the whole acquisition process. Metal nanoparticles are excellent probes to track the lateral drifts as they provide crisp and photostable information. However, achieving nanometre axial super-localization is still a major challenge, as diffraction imposes large depths-of-fields. Here we demonstrate fast full three-dimensional nanometre super-localization of gold nanoparticles through simultaneous intensity and phase imaging with a wavefront-sensing camera based on quadriwave lateral shearing interferometry. We show how to combine the intensity and phase information to provide the key to the third axial dimension. Presently, we demonstrate even in the occurrence of large three-dimensional fluctuations of several microns, unprecedented sub-nanometre localization accuracies down to 0.7 nm in lateral and 2.7 nm in axial directions at 50 frames per second. We demonstrate that nanoscale stabilization greatly enhances the image quality and resolution in direct stochastic optical reconstruction microscopy imaging.

3D single-molecule super-resolution microscopy with a tilted light sheet.

PubMed

Gustavsson, Anna-Karin; Petrov, Petar N; Lee, Maurice Y; Shechtman, Yoav; Moerner, W E

2018-01-09

Tilted light sheet microscopy with 3D point spread functions (TILT3D) combines a novel, tilted light sheet illumination strategy with long axial range point spread functions (PSFs) for low-background, 3D super-localization of single molecules as well as 3D super-resolution imaging in thick cells. Because the axial positions of the single emitters are encoded in the shape of each single-molecule image rather than in the position or thickness of the light sheet, the light sheet need not be extremely thin. TILT3D is built upon a standard inverted microscope and has minimal custom parts. The result is simple and flexible 3D super-resolution imaging with tens of nm localization precision throughout thick mammalian cells. We validate TILT3D for 3D super-resolution imaging in mammalian cells by imaging mitochondria and the full nuclear lamina using the double-helix PSF for single-molecule detection and the recently developed tetrapod PSFs for fiducial bead tracking and live axial drift correction.

Design and commissioning of an aberration-corrected ultrafast spin-polarized low energy electron microscope with multiple electron sources.

PubMed

Wan, Weishi; Yu, Lei; Zhu, Lin; Yang, Xiaodong; Wei, Zheng; Liu, Jefferson Zhe; Feng, Jun; Kunze, Kai; Schaff, Oliver; Tromp, Ruud; Tang, Wen-Xin

2017-03-01

We describe the design and commissioning of a novel aberration-corrected low energy electron microscope (AC-LEEM). A third magnetic prism array (MPA) is added to the standard AC-LEEM with two prism arrays, allowing the incorporation of an ultrafast spin-polarized electron source alongside the standard cold field emission electron source, without degrading spatial resolution. The high degree of symmetries of the AC-LEEM are utilized while we design the electron optics of the ultrafast spin-polarized electron source, so as to minimize the deleterious effect of time broadening, while maintaining full control of electron spin. A spatial resolution of 2nm and temporal resolution of 10ps (ps) are expected in the future time resolved aberration-corrected spin-polarized LEEM (TR-AC-SPLEEM). The commissioning of the three-prism AC-LEEM has been successfully finished with the cold field emission source, with a spatial resolution below 2nm. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of an enhanced resolution triple quadrupole mass spectrometer for high-throughput liquid chromatography/tandem mass spectrometry assays.

PubMed

Yang, Liyu; Amad, Ma'an; Winnik, Witold M; Schoen, Alan E; Schweingruber, Hans; Mylchreest, Iain; Rudewicz, Patrick J

2002-01-01

Triple quadrupole mass spectrometers, when operated in multiple reaction monitoring (MRM) mode, offer a unique combination of sensitivity, specificity, and dynamic range. Consequently, the triple quadrupole is the workhorse for high-throughput quantitation within the pharmaceutical industry. However, in the past, the unit mass resolution of quadrupole instruments has been a limitation when interference from matrix or metabolites cannot be eliminated. With recent advances in instrument design, triple quadrupole instruments now afford mass resolution of less than 0.1 Dalton (Da) full width at half maximum (FWHM). This paper describes the evaluation of an enhanced resolution triple quadrupole mass spectrometer for high-throughput bioanalysis with emphasis on comparison of selectivity, sensitivity, dynamic range, precision, accuracy, and stability under both unit mass (1 Da FWHM) and enhanced (

Magnetoacoustic Imaging of Electrical Conductivity of Biological Tissues at a Spatial Resolution Better than 2 mm

PubMed Central

Hu, Gang; He, Bin

2011-01-01

Magnetoacoustic tomography with magnetic induction (MAT-MI) is an emerging approach for noninvasively imaging electrical impedance properties of biological tissues. The MAT-MI imaging system measures ultrasound waves generated by the Lorentz force, having been induced by magnetic stimulation, which is related to the electrical conductivity distribution in tissue samples. MAT-MI promises to provide fine spatial resolution for biological tissue imaging as compared to ultrasound resolution. In the present study, we first estimated the imaging spatial resolution by calculating the full width at half maximum (FWHM) of the system point spread function (PSF). The actual spatial resolution of our MAT-MI system was experimentally determined to be 1.51 mm by a parallel-line-source phantom with Rayleigh criterion. Reconstructed images made from tissue-mimicking gel phantoms, as well as animal tissue samples, were consistent with the morphological structures of the samples. The electrical conductivity value of the samples was determined directly by a calibrated four-electrode system. It has been demonstrated that MAT-MI is able to image the electrical impedance properties of biological tissues with better than 2 mm spatial resolution. These results suggest the potential of MAT-MI for application to early detection of small-size diseased tissues (e.g. small breast cancer). PMID:21858111

Gamma-Ray Focusing Optics for Small Animal Imaging

NASA Technical Reports Server (NTRS)

Pivovaroff, M. J.; Barber, W. C.; Craig, W. W.; Hasegawa, B. H.; Ramsey, B. D.; Taylor, C.

2004-01-01

There is a well-established need for high-resolution radionuclide imaging techniques that provide non-invasive measurement of physiological function in small animals. We, therefore, have begun developing a small animal radionuclide imaging system using grazing incidence mirrors to focus low-energy gamma-rays emitted by I-125, and other radionuclides. Our initial prototype optic, fabricated from thermally-formed glass, demonstrated a resolution of 1500 microns, consistent with the performance predicted by detailed simulations. More recently, we have begun constructing mirrors using a replication technique that reduces low spatial frequency errors in the mirror surface, greatly improving the resolution. Each technique offers particular advantages: e.g., multilayer coatings are easily deposited on glass, while superior resolution is possible with replicated optics. Scaling the results from our prototype optics, which only have a few nested shells, to system where the lens has a full complement of several tens of nested shells, a sensitivity of approx. 1 cps/micro Ci is possible, with the exact number dependent on system magnification and radionuclide species. (Higher levels of efficiency can be obtained with multi-optic imaging systems.) The gamma-ray lens will achieve a resolution as good as 100 microns, independent of the final sensitivity. The combination of high spatial resolution and modest sensitivity will enable in vivo single photon emission imaging studies in small animals.

GPU-accelerated two dimensional synthetic aperture focusing for photoacoustic microscopy

NASA Astrophysics Data System (ADS)

Liu, Siyu; Feng, Xiaohua; Gao, Fei; Jin, Haoran; Zhang, Ruochong; Luo, Yunqi; Zheng, Yuanjin

2018-02-01

Acoustic resolution photoacoustic microscopy (AR-PAM) generally suffers from limited depth of focus, which had been extended by synthetic aperture focusing techniques (SAFTs). However, for three dimensional AR-PAM, current one dimensional (1D) SAFT and its improved version like cross-shaped SAFT do not provide isotropic resolution in the lateral direction. The full potential of the SAFT remains to be tapped. To this end, two dimensional (2D) SAFT with fast computing architecture is proposed in this work. Explained by geometric modeling and Fourier acoustics theories, 2D-SAFT provide the narrowest post-focusing capability, thus to achieve best lateral resolution. Compared with previous 1D-SAFT techniques, the proposed 2D-SAFT improved the lateral resolution by at least 1.7 times and the signal-to-noise ratio (SNR) by about 10 dB in both simulation and experiments. Moreover, the improved 2D-SAFT algorithm is accelerated by a graphical processing unit that reduces the long period of reconstruction to only a few seconds. The proposed 2D-SAFT is demonstrated to outperform previous reported 1D SAFT in the aspects of improving the depth of focus, imaging resolution, and SNR with fast computational efficiency. This work facilitates future studies on in vivo deeper and high-resolution photoacoustic microscopy beyond several centimeters.

A 4.2 ps Time-Interval RMS Resolution Time-to-Digital Converter Using a Bin Decimation Method in an UltraScale FPGA

NASA Astrophysics Data System (ADS)

Wang, Yonggang; Liu, Chong

2016-10-01

The common solution for a field programmable gate array (FPGA)-based time-to-digital converter (TDC) is constructing a tapped delay line (TDL) for time interpolation to yield a sub-clock time resolution. The granularity and uniformity of the delay elements of TDL determine the TDC time resolution. In this paper, we propose a dual-sampling TDL architecture and a bin decimation method that could make the delay elements as small and uniform as possible, so that the implemented TDCs can achieve a high time resolution beyond the intrinsic cell delay. Two identical full hardware-based TDCs were implemented in a Xilinx UltraScale FPGA for performance evaluation. For fixed time intervals in the range from 0 to 440 ns, the average time-interval RMS resolution is measured by the two TDCs with 4.2 ps, thus the timestamp resolution of single TDC is derived as 2.97 ps. The maximum hit rate of the TDC is as high as half the system clock rate of FPGA, namely 250 MHz in our demo prototype. Because the conventional online bin-by-bin calibration is not needed, the implementation of the proposed TDC is straightforward and relatively resource-saving.

Spatial resolution recovery utilizing multi-ray tracing and graphic processing unit in PET image reconstruction.

PubMed

Liang, Yicheng; Peng, Hao

2015-02-07

Depth-of-interaction (DOI) poses a major challenge for a PET system to achieve uniform spatial resolution across the field-of-view, particularly for small animal and organ-dedicated PET systems. In this work, we implemented an analytical method to model system matrix for resolution recovery, which was then incorporated in PET image reconstruction on a graphical processing unit platform, due to its parallel processing capacity. The method utilizes the concepts of virtual DOI layers and multi-ray tracing to calculate the coincidence detection response function for a given line-of-response. The accuracy of the proposed method was validated for a small-bore PET insert to be used for simultaneous PET/MR breast imaging. In addition, the performance comparisons were studied among the following three cases: 1) no physical DOI and no resolution modeling; 2) two physical DOI layers and no resolution modeling; and 3) no physical DOI design but with a different number of virtual DOI layers. The image quality was quantitatively evaluated in terms of spatial resolution (full-width-half-maximum and position offset), contrast recovery coefficient and noise. The results indicate that the proposed method has the potential to be used as an alternative to other physical DOI designs and achieve comparable imaging performances, while reducing detector/system design cost and complexity.

The Three-Dimensional Point Spread Function of Aberration-Corrected Scanning Transmission Electron Microscopy

PubMed Central

Lupini, A.R.; de Jonge, N.

2012-01-01

Aberration-correction reduces the depth of field in scanning transmission electron microscopy (STEM) and thus allows three-dimensional imaging by depth-sectioning. This imaging mode offers the potential for sub-Ångstrom lateral resolution and nanometer-scale depth sensitivity. For biological samples, which may be many microns across and where high lateral resolution may not always be needed, optimizing the depth resolution even at the expense of lateral resolution may be desired, aiming to image through thick specimens. Although there has been extensive work examining and optimizing the probe formation in two-dimensions, there is less known about the probe shape along the optical axis. Here the probe shape is examined in three-dimensions in an attempt to better understand the depth-resolution in this mode. Examples are presented of how aberrations change the probe shape in three-dimensions, and it is found that off-axial aberrations may need to be considered for focal series of large areas. It is shown that oversized or annular apertures theoretically improve the vertical resolution for 3D imaging of nanoparticles. When imaging nanoparticles of several nanometer size, regular STEM can thereby be optimized such that the vertical full width at half maximum approaches that of the aberration corrected STEM with a standard aperture. PMID:21878149

Using 3D Printers to Model Earth Surface Topography for Increased Student Understanding and Retention

NASA Astrophysics Data System (ADS)

Thesenga, David; Town, James

2014-05-01

In February 2000, the Space Shuttle Endeavour flew a specially modified radar system during an 11-day mission. The purpose of the multinational Shuttle Radar Topography Mission (SRTM) was to "obtain elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth" by using radar interferometry. The data and resulting products are now publicly available for download and give a view of the landscape removed of vegetation, buildings, and other structures. This new view of the Earth's topography allows us to see previously unmapped or poorly mapped regions of the Earth as well as providing a level of detail that was previously unknown using traditional topographic mapping techniques. Understanding and appreciating the geographic terrain is a complex but necessary requirement for middle school aged (11-14yo) students. Abstract in nature, topographic maps and other 2D renderings of the Earth's surface and features do not address the inherent spatial challenges of a concrete-learner and traditional methods of teaching can at times exacerbate the problem. Technological solutions such as 3D-imaging in programs like Google Earth are effective but lack the tactile realness that can make a large difference in learning comprehension and retention for these young students. First developed in the 1980's, 3D printers were not commercial reality until recently and the rapid rise in interest has driven down the cost. With the advent of sub US1500 3D printers, this technology has moved out of the high-end marketplace and into the local office supply store. Schools across the US and elsewhere in the world are adding 3D printers to their technological workspaces and students have begun rapid-prototyping and manufacturing a variety of projects. This project attempted to streamline the process of transforming SRTM data from a GeoTIFF format by way of Python code. The resulting data was then inputted into a CAD-based program for visualization and exporting as a .stl file for 3D printing. A proposal for improving the method and making it more accessible to middle school aged students is provided. Using the SRTM data to print a hand-held visual representation of a portion of the Earth's surface would utilize existing technology in the school and alter how topography can be taught in the classroom. Combining methods of 2D paper representations, on-screen 3D visualizations, and 3D hand-held models, give students the opportunity to truly grasp and retain the information being provided.

Abbreviated breast magnetic resonance protocol: Value of high-resolution temporal dynamic sequence to improve lesion characterization.

PubMed

Oldrini, Guillaume; Fedida, Benjamin; Poujol, Julie; Felblinger, Jacques; Trop, Isabelle; Henrot, Philippe; Darai, Emile; Thomassin-Naggara, Isabelle

2017-10-01

To evaluate the added value of ULTRAFAST-MR sequence to an abbreviated FAST protocol in comparison with FULL protocol to distinguish benign from malignant lesions in a population of women, regardless of breast MR imaging indication. From March 10th to September 22th, 2014, we retrospectively included a total of 70 consecutive patients with 106 histologically proven lesions (58 malignant and 48 benign) who underwent breast MR imaging for preoperative breast staging (n=38), high-risk screening (n=7), problem solving (n=18), and nipple discharge (n=4) with 12 time resolved imaging of contrast kinetics (TRICKS) acquisitions during contrast inflow interleaved in a regular high-resolution dynamic MRI protocol (FULL protocol). Two readers scored MR exams as either positive or negative and described significant lesions according to Bi-RADS lexicon with a TRICKS images (ULTRAFAST), an abbreviated protocol (FAST) and all images (FULL protocol). Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for each protocol and compared with McNemar's test. For all readers, the combined FAST-ULTRAFAST protocol significantly improved the reading with a specificity of 83.3% and 70.8% in comparison with FAST protocol or FULL protocol, respectively, without change in sensitivity. By adding ULTRAFAST protocol to FAST protocol, readers 1 and 2 were able to correctly change the diagnosis in 22.9% (11/48) and 10.4% (5/48) of benign lesions, without missing any malignancy, respectively. Both interpretation and image acquisition times for combined FAST-ULTRAFAST protocol and FAST protocol were shorter compared to FULL protocol (p<0.001). Compared to FULL protocol, adding ULTRAFAST to FAST protocol improves specificity, mainly in correctly reclassifying benign masses and reducing interpretation and acquisition time, without decreasing sensitivity. Copyright © 2017 Elsevier B.V. All rights reserved.

Overview of Suomi National Polar-Orbiting Partnership (NPP) Satellite Instrument Calibration and Validation

NASA Astrophysics Data System (ADS)

Weng, F.

2015-12-01

The Suomi National Polar-Orbiting Partnership (SNPP) satellite carries five instruments on board including ATMS, CrIS, VIIRS, OMPS and CERES. During the SNPP intensive calval, ATMS was pitched over to observe the cold space radiation. This unique data set was used for diagnostics of the ATMS scan-angle dependent bias and a scan-to-scan variation. A new algorithm is proposed to correct the ATMS scan angle dependent bias related to the reflector emission. ATMS radiometric calibration is also revised in IDPS with the full radiance processing (FRP). CrIS is the first Fourier transform Michelson interferometer and measures three infrared spectral bands from 650 to 1095, 1210 to 1750 and 2155 to 2550 cm-1 with spectral resolutions of 0.625 cm-1, respectively. Its spectral calibration is with an accuracy of better than 2 ppm and its noise is also well characterized with the Allan variance. Since CrIS was switched to the transmission of full spectral resolution (FSR) of RDR data to the ground in January 2015. The CrIS FSR SDR data are also produced offline at NOAA STAR. VIIRS has 22 spectral bands covering the spectrum between 0.412 μm and 12.01 μm, including 16 moderate resolution bands (M-bands) with a spatial resolution of 750 m at nadir, five imaging resolution bands (I-bands) with a spatial resolution of 375 m at nadir, and one day-night band (DNB) with a nearly-constant 750 m spatial resolution throughout the scan. The calibration of VIIRS reflective solar bands (RSB) requires a solar diffuser (SD) and a solar diffuser stability monitor (SDSM). Using the SNPP yaw maneuver data, SDSM screen transmission function can be updated to better capture the fine structures of the vignetting function. For OMPS nadir mapper (NM) and nadir profiler (NP), the detector signal-to-noise ratio, and sensor signal-to-noise ratio meet the system requirement. Detector gain and bias performance trends are generally stable. System linearity performance is stable and highly consistent with the prelaunch values. The recent updates on OMPS wavelength, solar flux and radiance coefficients have resulted in viewing angle dependent bias in the earth view observations. OMPS dark currents are updated weekly and monitored for further improving the radiometric calibration.

Chandra Reads the Cosmic Bar Code of Gas Around a Black Hole

NASA Astrophysics Data System (ADS)

2000-02-01

An international team of astronomers has used NASA's Chandra X-ray Observatory to make an energy bar code of hot gas in the vicinity of a giant black hole. These measurements, the most precise of their kind ever made with an X-ray telescope, demonstrate the existence of a blanket of warm gas that is expanding rapidly away from the black hole. The team consists of Jelle Kaastra, Rolf Mewe and Albert Brinkman of Space Research Organization Netherlands (SRON) in Utrecht, Duane Liedahl of Lawrence Livermore National Laboratory in Livermore, Calif., and Stefanie Komossa of Max Planck Institute in Garching, Germany. A report of their findings will be published in the March issue of the European journal Astronomy & Astrophysics. Kaastra and colleagues used the Low Energy Transmission Grating in conjunction with the High Resolution Camera to measure the number of X rays present at each energy. With this information they constructed an X-ray spectrum of the source. Their target was the central region, or nucleus of the galaxy NGC 5548, which they observed for 24 hours. This galaxy is one of a class of galaxies known to have unusually bright nuclei that are associated with gas flowing around and into giant black holes. This inflow produces an enormous outpouring of energy that blows some of the matter away from the black hole. Astronomers have used optical, ultraviolet, and X-ray telescopes in an effort to disentangle the complex nature of inflowing and outflowing gas at different distances from the black hole in NGC 5548. X-ray observations provide a ringside seat to the action around the black hole. By using the Low Energy Transmission Grating, the Dutch-US-German team concentrated on gas that forms a warm blanket that partially covers the innermost region where the highest energy X-rays are produced. As the high-energy X rays stream away from the vicinity of the black hole, they heat the blanketing gas to temperatures of a few million degrees, and the blanket absorbs some of the X rays from the central source. This produces dark stripes, or absorption lines in the X-ray spectrum. Bright stripes or emission lines due to emission from the blanketing gas are also present. Since each element has its own unique structure, these lines can be read like a cosmic bar code to take inventory of the gas. The team was able to determine what atoms the gas contains and how many, the number of electrons each atom has retained in the hostile environment of the black hole, and how the gas is moving there. They found lines from eight different elements including carbon, nitrogen, oxygen, and iron. The amount of this gas was found to be about 100 times greater than that found with optical and ultraviolet observations. The Low Energy Transmission Grating was built by the SRON. and the Max Planck Institute under the direction of Albert Brinkman. The High Resolution Camera was built by the Smithsonian Astrophysical Observatory in Cambridge, Mass. under the direction of Stephen Murray. To follow Chandra's progress or download images visit the Chandra sites at: http://chandra.harvard.edu/photo/2000/0170/index.html AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. High resolution digital versions of the X-ray spectrum (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu

Sub-pixel Area Calculation Methods for Estimating Irrigated Areas.

PubMed

Thenkabailc, Prasad S; Biradar, Chandrashekar M; Noojipady, Praveen; Cai, Xueliang; Dheeravath, Venkateswarlu; Li, Yuanjie; Velpuri, Manohar; Gumma, Muralikrishna; Pandey, Suraj

2007-10-31

The goal of this paper was to develop and demonstrate practical methods forcomputing sub-pixel areas (SPAs) from coarse-resolution satellite sensor data. Themethods were tested and verified using: (a) global irrigated area map (GIAM) at 10-kmresolution based, primarily, on AVHRR data, and (b) irrigated area map for India at 500-mbased, primarily, on MODIS data. The sub-pixel irrigated areas (SPIAs) from coarse-resolution satellite sensor data were estimated by multiplying the full pixel irrigated areas(FPIAs) with irrigated area fractions (IAFs). Three methods were presented for IAFcomputation: (a) Google Earth Estimate (IAF-GEE); (b) High resolution imagery (IAF-HRI); and (c) Sub-pixel de-composition technique (IAF-SPDT). The IAF-GEE involvedthe use of "zoom-in-views" of sub-meter to 4-meter very high resolution imagery (VHRI)from Google Earth and helped determine total area available for irrigation (TAAI) or netirrigated areas that does not consider intensity or seasonality of irrigation. The IAF-HRI isa well known method that uses finer-resolution data to determine SPAs of the coarser-resolution imagery. The IAF-SPDT is a unique and innovative method wherein SPAs aredetermined based on the precise location of every pixel of a class in 2-dimensionalbrightness-greenness-wetness (BGW) feature-space plot of red band versus near-infraredband spectral reflectivity. The SPIAs computed using IAF-SPDT for the GIAM was within2 % of the SPIA computed using well known IAF-HRI. Further the fractions from the 2 methods were significantly correlated. The IAF-HRI and IAF-SPDT help to determine annualized or gross irrigated areas (AIA) that does consider intensity or seasonality (e.g., sum of areas from season 1, season 2, and continuous year-round crops). The national census based irrigated areas for the top 40 irrigated nations (which covers about 90% of global irrigation) was significantly better related (and had lesser uncertainties and errors) when compared to SPIAs than FPIAs derived using 10-km and 500-m data. The SPIAs were closer to actual areas whereas FPIAs grossly over-estimate areas. The research clearly demonstrated the value and the importance of sub-pixel areas as opposed to full pixel areas and presented 3 innovative methods for computing the same.

First imaging results from Apertif, a phased-array feed for WSRT

NASA Astrophysics Data System (ADS)

Adams, Elizabeth A.; Adebahr, Björn; de Blok, Willem J. G.; Hess, Kelley M.; Hut, Boudewijn; Lucero, Danielle M.; Maccagni, Filippo; Morganti, Raffaella; Oosterloo, Tom; Staveley-Smith, Lister; van der Hulst, Thijs; Verheijen, Marc; Verstappen, Joris

2017-01-01

Apertif is a phased-array feed for the Westerbork Synthesis Radio Telescope (WSRT), increasing the field of view of the telescope by a factor of twenty-five. In 2017, three legacy surveys will commence: a shallow imaging survey, a medium-deep imaging survey, and a pulsars and fast transients survey. The medium-deep imaging survey will include coverage of the northern Herschel Atlas field, the CVn region, HetDex, and the Perseus-Pisces supercluster. The shallow imaging survey increases overlap with HetDex, has expanded coverage of the Perseus-Pisces supercluster, and includes part of the Zone of Avoidance. Both imaging surveys are coordinating with MaNGA and will have WEAVE follow-up. The imaging surveys will be done in full polarization over the frequency range 1130-1430 MHz, which corresponds to redshifts of z=0-0.256 for neutral hydrogen (HI). The spectral resolution is 12.2 kHz, or an HI velocity resolution of 2.6 km/s at z=0 and 3.2 km/s at z=0.256. The full resolution images will have a beam size of 15"x15"/sin(declination), and tapered data products (i.e., 30" resolution images) will also be available. The shallow survey will cover ~3500 square degrees with a four-sigma HI imaging sensitivity of 2.5x10^20 atoms cm^-2 (20 km/s linewidth) at the highest resolution and a continuum sensitivity of 15 uJy/beam (11 uJy/beam for polarization data). The current plan calls for the medium deep survey to cover 450 square degrees and provide an HI imaging sensitivity of 1.0x10^20 atoms cm^-2 at the highest resolution and a continuum sensitivity of 6 uJy/beam, close to the confusion limit (4 uJy/beam for polarization data, not confusion limited). Up-to-date information on Apertif and the planned surveys can be found at: http://www.apertif.nl.Commissioning of the Apertif instrument is currently underway. Here we present first results from the image commissioning, including the detection of HI absorption plus continuum and HI imaging. These results highlight the data quality that will be achieved for the surveys.

42 CFR 455.16 - Resolution of full investigation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 455.16 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PROGRAM INTEGRITY: MEDICAID Medicaid Agency Fraud Detection and... further action; (2) Suspending or terminating the provider from participation in the Medicaid program; (3...

Colby Fire over LA Basin

Atmospheric Science Data Center

2014-05-15

... full resolution figures image   On Jan. 16, 2014, dry conditions and warm winter temperatures in California permitted embers from ... when viewed with red/blue glasses (red filter over the left eye). To give the stereoscopic effect, this image is rotated so that North is ...

All the Elements of National Power

DTIC Science & Technology

2016-03-01

sustainable peace. Anachronistic stereotypes regarding gender roles make for bad policy when provid- ing for the common defense. Often consigned to...That resolution “called for women’s equal participation with men and their full involvement in all efforts for the maintenance and promotion of

Researchers Use NRAO Telescope to Study Formation Of Chemical Precursors to Life

NASA Astrophysics Data System (ADS)

2006-08-01

In just two years of work, an international research team has discovered eight new complex, biologically-significant molecules in interstellar space using the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia. "This is a feat unprecedented in the 35-year history of searching for complex molecules in space and suggests that a universal prebiotic chemistry is at work," said Jan M. Hollis of the NASA Goddard Space Flight Center, leader of the research team. Chemistry Cycle The Cosmic Chemistry Cycle CREDIT: Bill Saxton, NRAO/AUI/NSF Full Size Image Files Interactive Graphic With "Mouseover" Text Blocks Chemical Cycle Graphic (above image, JPEG, 129K) Graphic With Text Blocks (JPEG, 165K) High-Res TIFF (44.2M) High-Res TIFF With Text Blocks (44.2M) Green Bank Telescope and Molecule Diagrams (JPEG, 58K) Green Bank Telescope and Molecule Diagrams (TIFF, 21M) New Molecules: Chemical Diagrams (PDF, 64K) The new discoveries are helping scientists unlock the secrets of how the molecular precursors to life can form in the giant clouds of gas and dust in which stars and planets are born. "The first of the many chemical processes that ultimately led to life on Earth probably took place even before our planet was formed. The GBT has taken the leading role in exploring the origin of biomolecules in interstellar clouds," said Phil Jewell of the National Radio Astronomy Observatory (NRAO). The eight new molecules discovered with the GBT bring the total to 141 different molecular species found in interstellar space. About 90 percent of those interstellar molecules contain carbon, which is required for a molecule to be classified as organic. The newly-discovered molecules all contain carbon and are composed of 6 to 11 atoms each. These results suggest, the scientists say, that chemical evolution occurs routinely in the gas and dust from which stars and planets eventually are born. The mass of an interstellar cloud is 99 percent gas and one percent dust. The GBT discoveries have been made in just two prototypical interstellar clouds. The molecules acetamide (CH3CONH2), cyclopropenone (H2C3O), propenal (CH2CHCHO), propanal (CH3CH2CHO), and ketenimine (CH2CNH) were found in a cloud called Sagittarius B2(N), which is near the center of our Milky Way Galaxy some 26,000 light years from Earth. This star-forming region is the largest repository of complex interstellar molecules known. The molecules methyl-cyano-diacetylene (CH3C5N), methyl-triacetylene (CH3C6H), and cyanoallene (CH2CCHCN) were found in the Taurus Molecular Cloud (TMC-1), which is relatively nearby at a distance of 450 light years. The starless TMC-1 cloud is dark and cold with a temperature of only 10 degrees above absolute zero and may eventually evolve into a star-forming region. "The discovery of these large organic molecules in the coldest regions of the interstellar medium has certainly changed the belief that large organic molecules would only have their origins in hot molecular cores. It has forced us to rethink the paradigms of interstellar chemistry," said Anthony Remijan of the NRAO. These large molecules found with the GBT are built up from smaller ones, the scientists say, by two principal mechanisms. In the first, simple chemical reactions add an atom to a molecular structure residing on the surface of a dust grain. As an example of this process, the researchers cite a molecule called cyclopropenylidene (c-C3H2, where "c-" means cyclic), which contains three carbon atoms in a ring. Cyclopropenylidene was discovered in interstellar space in 1987, and is known to be highly reactive. In 2005, using the GBT, scientists discovered another molecule, cyclopropenone (c-H2C3O), which can be produced by adding an oxygen atom to cyclopropenylidene. The second method for constructing larger molecules from smaller ones involves neutral-radical reactions that can occur within the gas in an interstellar cloud. For example, in 2006, the scientists discovered acetamide (CH3CONH2), which can be formed when a previously-discovered neutral molecule called formamide (HCONH2) combines with radicals such as CH2 and CH3, also previously discovered. Acetamide is particularly interesting because it contains a peptide bond which is the means for linking amino acids together to form proteins. Once interstellar molecules are ejected from dust grains into the gas phase, presumably by shock waves, they are free to rotate end-over-end. As gas molecules change their rotational modes, they can emit or absorb radiation at precise radio frequencies, called transitions, that are unique to each type of molecule. By detecting several rotational transitions, astronomers can unambiguously identify a specific interstellar molecule. "It is important to note that likely interstellar molecule candidates are first studied in gas-phase laboratory experiments so that transition frequencies are known in advance of an interstellar experiment," said Frank Lovas of the National Institute of Standards and Technology. Along the line of sight from the interstellar cloud to the telescope, thousands of billions of molecules undergo the exact same transition, producing a signal strong enough to be detected by sensitive equipment. For this type of work, the GBT is the world's most sensitive tool that can be accurately pointed and track astronomical objects. In addition to Hollis, Jewell, Remijan, and Lovas, the research team included Lewis Snyder of the University of Illinois; Harald Mollendal of the University of Oslo, Norway; Vadim Ilyushin of the Institute of Radio Astronomy of the National Academy of Sciences of the Ukraine; and Isabell Kleiner of the Universite Paris, France. The astronomers' reports on their results appeared in 8 separate editions of the Astrophysical Journal. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Real-time full-motion color Flash lidar for target detection and identification

NASA Astrophysics Data System (ADS)

Nelson, Roy; Coppock, Eric; Craig, Rex; Craner, Jeremy; Nicks, Dennis; von Niederhausern, Kurt

2015-05-01

Greatly improved understanding of areas and objects of interest can be gained when real time, full-motion Flash LiDAR is fused with inertial navigation data and multi-spectral context imagery. On its own, full-motion Flash LiDAR provides the opportunity to exploit the z dimension for improved intelligence vs. 2-D full-motion video (FMV). The intelligence value of this data is enhanced when it is combined with inertial navigation data to produce an extended, georegistered data set suitable for a variety of analysis. Further, when fused with multispectral context imagery the typical point cloud now becomes a rich 3-D scene which is intuitively obvious to the user and allows rapid cognitive analysis with little or no training. Ball Aerospace has developed and demonstrated a real-time, full-motion LIDAR system that fuses context imagery (VIS to MWIR demonstrated) and inertial navigation data in real time, and can stream these information-rich geolocated/fused 3-D scenes from an airborne platform. In addition, since the higher-resolution context camera is boresighted and frame synchronized to the LiDAR camera and the LiDAR camera is an array sensor, techniques have been developed to rapidly interpolate the LIDAR pixel values creating a point cloud that has the same resolution as the context camera, effectively creating a high definition (HD) LiDAR image. This paper presents a design overview of the Ball TotalSight™ LIDAR system along with typical results over urban and rural areas collected from both rotary and fixed-wing aircraft. We conclude with a discussion of future work.

FWT2D: A massively parallel program for frequency-domain full-waveform tomography of wide-aperture seismic data—Part 1: Algorithm

NASA Astrophysics Data System (ADS)

Sourbier, Florent; Operto, Stéphane; Virieux, Jean; Amestoy, Patrick; L'Excellent, Jean-Yves

2009-03-01

This is the first paper in a two-part series that describes a massively parallel code that performs 2D frequency-domain full-waveform inversion of wide-aperture seismic data for imaging complex structures. Full-waveform inversion methods, namely quantitative seismic imaging methods based on the resolution of the full wave equation, are computationally expensive. Therefore, designing efficient algorithms which take advantage of parallel computing facilities is critical for the appraisal of these approaches when applied to representative case studies and for further improvements. Full-waveform modelling requires the resolution of a large sparse system of linear equations which is performed with the massively parallel direct solver MUMPS for efficient multiple-shot simulations. Efficiency of the multiple-shot solution phase (forward/backward substitutions) is improved by using the BLAS3 library. The inverse problem relies on a classic local optimization approach implemented with a gradient method. The direct solver returns the multiple-shot wavefield solutions distributed over the processors according to a domain decomposition driven by the distribution of the LU factors. The domain decomposition of the wavefield solutions is used to compute in parallel the gradient of the objective function and the diagonal Hessian, this latter providing a suitable scaling of the gradient. The algorithm allows one to test different strategies for multiscale frequency inversion ranging from successive mono-frequency inversion to simultaneous multifrequency inversion. These different inversion strategies will be illustrated in the following companion paper. The parallel efficiency and the scalability of the code will also be quantified.

High-speed holographic system for full-field transient vibrometry of the human tympanic membrane

NASA Astrophysics Data System (ADS)

Dobrev, I.; Harrington, E. J.; Cheng, T.; Furlong, C.; Rosowski, J. J.

2014-07-01

Understanding of the human hearing process requires the quantification of the transient response of the human ear and the human tympanic membrane (TM or eardrum) in particular. Current state-of-the-art medical methods to quantify the transient acousto-mechanical response of the TM provide only averaged acoustic or local information at a few points. This may be insufficient to fully describe the complex patterns unfolding across the full surface of the TM. Existing engineering systems for full-field nanometer measurements of transient events, typically based on holographic methods, constrain the maximum sampling speed and/or require complex experimental setups. We have developed and implemented of a new high-speed (i.e., > 40 Kfps) holographic system (HHS) with a hybrid spatio-temporal local correlation phase sampling method that allows quantification of the full-field nanometer transient (i.e., > 10 kHz) displacement of the human TM. The HHS temporal accuracy and resolution is validated versus a LDV on both artificial membranes and human TMs. The high temporal (i.e., < 24 μs) and spatial (i.e., >100k data points) resolution of our HHS enables simultaneous measurement of the time waveform of the full surface of the TM. These capabilities allow for quantification of spatially-dependent motion parameters such as energy propagation delays surface wave speeds, which can be used to infer local material properties across the surface of the TM. The HHS could provide a new tool for the investigation of the auditory system with applications in medical research, in-vivo clinical diagnosis as well as hearing aids design.

MODTRAN3: Suitability as a flux-divergence code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, G.P.; Chetwynd, J.H.; Wang, J.

1995-04-01

The Moderate Resolution Atmospheric Radiance and Transmittance Model (MODTRAN3) is the developmental version of MODTRAN and MODTRAN2. The Geophysics Directorate, Phillips Laboratory, released a beta version of this model in October 1994. It encompasses all the capabilities of LOWTRAN7, the historic 20 cm{sup -1} resolution (full width at half maximum, FWHM) radiance code, but incorporates a much more sensitive molecular band model with 2 cm{sup -1} resolution. The band model is based directly upon the HITRAN spectral parameters, including both temperature and pressure (line shape) dependencies. Validation against full Voigt line-by-line calculations (e.g., FASCODE) has shown excellent agreement. In addition,more » simple timing runs demonstrate potential improvement of more than a factor of 100 for a typical 500 cm{sup -1} spectral interval and comparable vertical layering. Not only is MODTRAN an excellent band model for {open_quotes}full path{close_quotes} calculations (that is, radiance and/or transmittance from point A to point B), but it replicates layer-specific quantities to a very high degree of accuracy. Such layer quantities, derived from ratios and differences of longer path MODTRAN calculations from point A to adjacent layer boundaries, can be used to provide inversion algorithm weighting functions or similarly formulated quantities. One of the most exciting new applications is the rapid calculation of reliable IR cooling rates, including species, altitude, and spectral distinctions, as well as the standard spectrally integrated quantities. Comparisons with prior line-by-line cooling rate calculations are excellent, and the techniques can be extended to incorporate global climatologies of both standard and trace atmospheric species.« less

Optical biopsy on head and neck tissue using full-field OCT: a pilot study

NASA Astrophysics Data System (ADS)

De Leeuw, Frédéric; Latrive, Anne; Casiraghi, Odile; Ferchiou, Malek; Harms, Fabrice; Boccara, Claude; Laplace-Builhé, Corinne

2014-03-01

Here we evaluate the clinical value of Full-Field OCT imaging in the management of patients with Head and Neck cancers by making a reliable histological diagnosis on FFOCT images produced during preoperative procedure. FFOCT performs a true "virtual extemporaneous exam" that we want to compare to the gold standard (extemporaneous and conventional histology with H and E staining). This new optical technology could be useful when diagnosing a lesion, cancerous or precancerous, or at the time of its surgical management. Full-Field Optical Coherence Tomography virtually slices the tissue using white light interferometry to produce in-depth 2D images with an isotropic resolution around 1 micrometer. With such a high resolution FFOCT systems produce "optical biopsy" images that are similar to that obtained with classical histology procedures, but without any staining and in only a few minutes. We imaged freshly excised samples from patients, of mouth, tongue, epiglottis and larynx tissues, both healthy and cancerous. FFOCT images were acquired and later compared with histology of the same samples. Common features were identified and characteristics of each tissue type were matched in order to form an image atlas for pathologist training. We were able to identify indicators of tumors such as heterogeneities in cell distribution, surrounding stroma, anomalous keratinization… In conclusion, FFOCT is a fast, non-invasive, non-destructive imaging tool that can be inserted into the pathology lab workflow and can provide a quick assessment of microscopic tissue architecture and content. Furthermore we are developing a similar system with a rigid endoscopic probe in order to do in vivo and in situ high-resolution imaging. Our probe could thus guide the surgeon in real time before and during excision and ensure a more precise gesture.

Determination of the resolution of the x-ray microscope XM-1 at beamline 6.1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heck, J.M.; Meyer-Ilse, W.; Attwood, D.T.

1997-04-01

Resolution determination in x-ray microscopy is a complex issue which depends on many factors. Many different criteria and experimental setups are used to characterize resolution. Some of the important factors affecting resolution include the partial coherence and spectrum of the illumination. The purpose of this research has been to measure the resolution of XM-1 at beamline 6.1 taking into account these factors, and to compare the measurements to theoretical calculations. The x-ray microscope XM-1, built by the Center for X-ray Optics (CXRO), has been operational since 1994 at the Advanced Light Source at E.O. Lawrence Berkeley National Laboratory. It ismore » of the conventional (i.e. full-field) type, utilizing zone plate optics. ALS bending magnet radiation is focused by a condenser zone plate onto a monochromator pinhole immediately in front of the sample. X-rays transmitted through the sample are focused by a micro-zone plate onto a CCD camera. The pinhole and the condenser with a central stop constitute a linear monochromator. The spectral distribution of the light illuminating the sample has been calculated assuming geometrical optics.« less

VizieR Online Data Catalog: The Fermi-GBM three-year X-ray burst catalog (Jenke+, 2016)

NASA Astrophysics Data System (ADS)

Jenke, P. A.; Linares, M.; Connaughton, V.; Beklen, E.; Camero-Arranz, A.; Finger, M. H.; Wilson-Hodge, C. A.

2018-03-01

Gamma-ray Burst Monitor (GBM) is an all-sky monitor whose primary objective is to extend the energy range over which gamma-ray bursts are observed in the Large Area Telescope on Fermi (Meegan et al. 2009ApJ...702..791M). GBM consists of 12 NaI detectors with a diameter of 12.7 cm and a thickness of 1.27 cm and two bismuth germanate (BGO) detectors with a diameter and thickness of 12.7 cm. GBM has three continuous data types: CTIME data with nominal 0.256 s time resolution and 8-channel spectral resolution used for event detection and localization, CSPEC data with nominal 4.096 s time resolution and 128-channel spectral resolution, which are used for spectral modeling, and CTTE (continuous-time tagged event) data with time stamps (2 μs precision) on individual events at full 128-channel spectral resolution, which were made available in 2012 November. The Fermi-GBM X-ray Burst Monitor relies on daily inspection of CTIME channel 1 (12-25 keV) data and began operations on 2010 March 12. (3 data files).

Numerical viscosity and resolution of high-order weighted essentially nonoscillatory schemes for compressible flows with high Reynolds numbers.

PubMed

Zhang, Yong-Tao; Shi, Jing; Shu, Chi-Wang; Zhou, Ye

2003-10-01

A quantitative study is carried out in this paper to investigate the size of numerical viscosities and the resolution power of high-order weighted essentially nonoscillatory (WENO) schemes for solving one- and two-dimensional Navier-Stokes equations for compressible gas dynamics with high Reynolds numbers. A one-dimensional shock tube problem, a one-dimensional example with parameters motivated by supernova and laser experiments, and a two-dimensional Rayleigh-Taylor instability problem are used as numerical test problems. For the two-dimensional Rayleigh-Taylor instability problem, or similar problems with small-scale structures, the details of the small structures are determined by the physical viscosity (therefore, the Reynolds number) in the Navier-Stokes equations. Thus, to obtain faithful resolution to these small-scale structures, the numerical viscosity inherent in the scheme must be small enough so that the physical viscosity dominates. A careful mesh refinement study is performed to capture the threshold mesh for full resolution, for specific Reynolds numbers, when WENO schemes of different orders of accuracy are used. It is demonstrated that high-order WENO schemes are more CPU time efficient to reach the same resolution, both for the one-dimensional and two-dimensional test problems.

High resolution flow field prediction for tail rotor aeroacoustics

NASA Technical Reports Server (NTRS)

Quackenbush, Todd R.; Bliss, Donald B.

1989-01-01

The prediction of tail rotor noise due to the impingement of the main rotor wake poses a significant challenge to current analysis methods in rotorcraft aeroacoustics. This paper describes the development of a new treatment of the tail rotor aerodynamic environment that permits highly accurate resolution of the incident flow field with modest computational effort relative to alternative models. The new approach incorporates an advanced full-span free wake model of the main rotor in a scheme which reconstructs high-resolution flow solutions from preliminary, computationally inexpensive simulations with coarse resolution. The heart of the approach is a novel method for using local velocity correction terms to capture the steep velocity gradients characteristic of the vortex-dominated incident flow. Sample calculations have been undertaken to examine the principal types of interactions between the tail rotor and the main rotor wake and to examine the performance of the new method. The results of these sample problems confirm the success of this approach in capturing the high-resolution flows necessary for analysis of rotor-wake/rotor interactions with dramatically reduced computational cost. Computations of radiated sound are also carried out that explore the role of various portions of the main rotor wake in generating tail rotor noise.

3D near-infrared imaging based on a single-photon avalanche diode array sensor

NASA Astrophysics Data System (ADS)

Mata Pavia, Juan; Charbon, Edoardo; Wolf, Martin

2011-07-01

An imager for optical tomography was designed based on a detector with 128×128 single-photon pixels that included a bank of 32 time-to-digital converters. Due to the high spatial resolution and the possibility of performing time resolved measurements, a new contact-less setup has been conceived in which scanning of the object is not necessary. This enables one to perform high-resolution optical tomography with much higher acquisition rate, which is fundamental in clinical applications. The setup has a resolution of 97ps and operates with a laser source with an average power of 3mW. This new imaging system generated a high amount of data that could not be processed by established methods, therefore new concepts and algorithms were developed to take full advantage of it. Images were generated using a new reconstruction algorithm that combined general inverse problem methods with Fourier transforms in order to reduce the complexity of the problem. Simulations show that the potential resolution of the new setup is in the order of millimeters. Experiments have been performed to confirm this potential. Images derived from the measurements demonstrate that we have already reached a resolution of 5mm.

High resolution diffraction imaging of crystals grown in microgravity and closely related terrestrial crystals

NASA Technical Reports Server (NTRS)

Steiner, B.; Dobbyn, R.; Black, D.; Burdette, H.; Kuriyama, M.; Spal, R.; Vandenberg, L.; Fripp, A.; Simchick, R.; Lal, R.

1991-01-01

Irregularities found in three crystals grown in space, in four crystals grown entirely on the ground were examined and compared. Irregularities were observed in mercuric iodide, lead tin telluride, triglycine sulfate, and gallium arsenide by high resolution synchrotron x radiation diffraction imaging. Radiation detectors made from mercuric iodide crystals grown in microgravity were reported to perform far better than conventional detectors grown from the same material under full gravity. Effort is now underway to reproduce these 'space' crystals, optimize their properties, and extend comparable superiority to other types of materials.

Comments on "Adaptive resolution simulation in equilibrium and beyond" by H. Wang and A. Agarwal

NASA Astrophysics Data System (ADS)

Klein, R.

2015-09-01

Wang and Agarwal (Eur. Phys. J. Special Topics, this issue, 2015, doi: 10.1140/epjst/e2015-02411-2) discuss variants of Adaptive Resolution Molecular Dynamics Simulations (AdResS), and their applications. Here we comment on their report, addressing scaling properties of the method, artificial forcings implemented to ensure constant density across the full simulation despite changing thermodynamic properties of the simulated media, the possible relation between an AdResS system on the one hand and a phase transition phenomenon on the other, and peculiarities of the SPC/E water model.

Optimisation of resolution in micellar electrokinetic chromatography by multivariate evaluation of electrolytes.

PubMed

Mikaeli, S; Thorsén, G; Karlberg, B

2001-01-12

A novel approach to multivariate evaluation of separation electrolytes for micellar electrokinetic chromatography is presented. An initial screening of the experimental parameters is performed using a Plackett-Burman design. Significant parameters are further evaluated using full factorial designs. The total resolution of the separation is calculated and used as response. The proposed scheme has been applied to the optimisation of the separation of phenols and the chiral separation of (+)-1-(9-anthryl)-2-propyl chloroformate-derivatized amino acids. A total of eight experimental parameters were evaluated and optimal conditions found in less than 48 experiments.

Integrated sensor with frame memory and programmable resolution for light adaptive imaging

NASA Technical Reports Server (NTRS)

Zhou, Zhimin (Inventor); Fossum, Eric R. (Inventor); Pain, Bedabrata (Inventor)

2004-01-01

An image sensor operable to vary the output spatial resolution according to a received light level while maintaining a desired signal-to-noise ratio. Signals from neighboring pixels in a pixel patch with an adjustable size are added to increase both the image brightness and signal-to-noise ratio. One embodiment comprises a sensor array for receiving input signals, a frame memory array for temporarily storing a full frame, and an array of self-calibration column integrators for uniform column-parallel signal summation. The column integrators are capable of substantially canceling fixed pattern noise.

Replicated Nickel Optics for the Hard-X-Ray Region

NASA Technical Reports Server (NTRS)

Ramsey, Brian

2005-01-01

Replicated nickel optics has been used extensively in x-ray astronomy, most notable for the XMM/Newton mission. Thc combination of relative ease of fabrication and the inherent stability of full shell optics, make them FIJI attractive approach for medium-resolution, high-throughput applications. MSFC has been developing these optics for use in the hard-x-ray region. Efforts at improving the resolution of these, particularly the very-thin shells required to meet thc weight budget of future missions, will be described together with the prospects for significant improvements down to the 5-arcsec level.

High resolution imaging and lithography with hard x rays using parabolic compound refractive lenses

NASA Astrophysics Data System (ADS)

Schroer, C. G.; Benner, B.; Günzler, T. F.; Kuhlmann, M.; Zimprich, C.; Lengeler, B.; Rau, C.; Weitkamp, T.; Snigirev, A.; Snigireva, I.; Appenzeller, J.

2002-03-01

Parabolic compound refractive lenses are high quality optical components for hard x rays. They are particularly suited for full field imaging, with applications in microscopy and x-ray lithography. Taking advantage of the large penetration depth of hard x rays, the interior of opaque samples can be imaged with submicrometer resolution. To obtain the three-dimensional structure of a sample, microscopy is combined with tomographic techniques. In a first hard x-ray lithography experiment, parabolic compound refractive lenses have been used to project the reduced image of a lithography mask onto a resist. Future developments are discussed.

Ultra-large field-of-view two-photon microscopy

PubMed Central

Tsai, Philbert S.; Mateo, Celine; Field, Jeffrey J.; Schaffer, Chris B.; Anderson, Matthew E.; Kleinfeld, David

2015-01-01

We present a two-photon microscope that images the full extent of murine cortex with an objective-limited spatial resolution across an 8 mm by 10 mm field. The lateral resolution is approximately 1 µm and the maximum scan speed is 5 mm/ms. The scan pathway employs large diameter compound lenses to minimize aberrations and performs near theoretical limits. We demonstrate the special utility of the microscope by recording resting-state vasomotion across both hemispheres of the murine brain through a transcranial window and by imaging histological sections without the need to stitch. PMID:26072755

Collimator optimization and collimator-detector response compensation in myocardial perfusion SPECT using the ideal observer with and without model mismatch and an anthropomorphic model observer

NASA Astrophysics Data System (ADS)

Ghaly, Michael; Links, Jonathan M.; Frey, Eric C.

2016-03-01

The collimator is the primary factor that determines the spatial resolution and noise tradeoff in myocardial perfusion SPECT images. In this paper, the goal was to find the collimator that optimizes the image quality in terms of a perfusion defect detection task. Since the optimal collimator could depend on the level of approximation of the collimator-detector response (CDR) compensation modeled in reconstruction, we performed this optimization for the cases of modeling the full CDR (including geometric, septal penetration and septal scatter responses), the geometric CDR, or no model of the CDR. We evaluated the performance on the detection task using three model observers. Two observers operated on data in the projection domain: the Ideal Observer (IO) and IO with Model-Mismatch (IO-MM). The third observer was an anthropomorphic Channelized Hotelling Observer (CHO), which operated on reconstructed images. The projection-domain observers have the advantage that they are computationally less intensive. The IO has perfect knowledge of the image formation process, i.e. it has a perfect model of the CDR. The IO-MM takes into account the mismatch between the true (complete and accurate) model and an approximate model, e.g. one that might be used in reconstruction. We evaluated the utility of these projection domain observers in optimizing instrumentation parameters. We investigated a family of 8 parallel-hole collimators, spanning a wide range of resolution and sensitivity tradeoffs, using a population of simulated projection (for the IO and IO-MM) and reconstructed (for the CHO) images that included background variability. We simulated anterolateral and inferior perfusion defects with variable extents and severities. The area under the ROC curve was estimated from the IO, IO-MM, and CHO test statistics and served as the figure-of-merit. The optimal collimator for the IO had a resolution of 9-11 mm FWHM at 10 cm, which is poorer resolution than typical collimators used for MPS. When the IO-MM and CHO used a geometric or no model of the CDR, the optimal collimator shifted toward higher resolution than that obtained using the IO and the CHO with full CDR modeling. With the optimal collimator, the IO-MM and CHO using geometric modeling gave similar performance to full CDR modeling. Collimators with poorer resolution were optimal when CDR modeling was used. The agreement of rankings between the IO-MM and CHO confirmed that the IO-MM is useful for optimization tasks when model mismatch is present due to its substantially reduced computational burden compared to the CHO.

Design and Performance of a 1 mm3 Resolution Clinical PET System Comprising 3-D Position Sensitive Scintillation Detectors.

PubMed

Hsu, David F C; Freese, David L; Reynolds, Paul D; Innes, Derek R; Levin, Craig S

2018-04-01

We are developing a 1-mm 3 resolution, high-sensitivity positron emission tomography (PET) system for loco-regional cancer imaging. The completed system will comprise two cm detector panels and contain 4 608 position sensitive avalanche photodiodes (PSAPDs) coupled to arrays of mm 3 LYSO crystal elements for a total of 294 912 crystal elements. For the first time, this paper summarizes the design and reports the performance of a significant portion of the final clinical PET system, comprising 1 536 PSAPDs, 98 304 crystal elements, and an active field-of-view (FOV) of cm. The sub-system performance parameters, such as energy, time, and spatial resolutions are predictive of the performance of the final system due to the modular design. Analysis of the multiplexed crystal flood histograms shows 84% of the crystal elements have>99% crystal identification accuracy. The 511 keV photopeak energy resolution was 11.34±0.06% full-width half maximum (FWHM), and coincidence timing resolution was 13.92 ± 0.01 ns FWHM at 511 keV. The spatial resolution was measured using maximum likelihood expectation maximization reconstruction of a grid of point sources suspended in warm background. The averaged resolution over the central 6 cm of the FOV is 1.01 ± 0.13 mm in the X-direction, 1.84 ± 0.20 mm in the Y-direction, and 0.84 ± 0.11 mm in the Z-direction. Quantitative analysis of acquired micro-Derenzo phantom images shows better than 1.2 mm resolution at the center of the FOV, with subsequent resolution degradation in the y-direction toward the edge of the FOV caused by limited angle tomography effects.

On the assessment of spatial resolution of PET systems with iterative image reconstruction

NASA Astrophysics Data System (ADS)

Gong, Kuang; Cherry, Simon R.; Qi, Jinyi

2016-03-01

Spatial resolution is an important metric for performance characterization in PET systems. Measuring spatial resolution is straightforward with a linear reconstruction algorithm, such as filtered backprojection, and can be performed by reconstructing a point source scan and calculating the full-width-at-half-maximum (FWHM) along the principal directions. With the widespread adoption of iterative reconstruction methods, it is desirable to quantify the spatial resolution using an iterative reconstruction algorithm. However, the task can be difficult because the reconstruction algorithms are nonlinear and the non-negativity constraint can artificially enhance the apparent spatial resolution if a point source image is reconstructed without any background. Thus, it was recommended that a background should be added to the point source data before reconstruction for resolution measurement. However, there has been no detailed study on the effect of the point source contrast on the measured spatial resolution. Here we use point source scans from a preclinical PET scanner to investigate the relationship between measured spatial resolution and the point source contrast. We also evaluate whether the reconstruction of an isolated point source is predictive of the ability of the system to resolve two adjacent point sources. Our results indicate that when the point source contrast is below a certain threshold, the measured FWHM remains stable. Once the contrast is above the threshold, the measured FWHM monotonically decreases with increasing point source contrast. In addition, the measured FWHM also monotonically decreases with iteration number for maximum likelihood estimate. Therefore, when measuring system resolution with an iterative reconstruction algorithm, we recommend using a low-contrast point source and a fixed number of iterations.

The Evolution of World Health Organization's Initiatives for the Strengthening of Nursing and Midwifery.

PubMed

Ventura, Carla Aparecida Arena; Mendes, Isabel Amélia Costa; Fumincelli, Laís; Trevizan, Maria Auxiliadora

2015-09-01

To describe the evolution in the resolutions approved by World Health Organization (WHO)'s World Health Assembly (WHA) to strengthen nursing and midwifery. Qualitative and descriptive study, undertaken through a search of resolutions presented by WHA, on the WHO website, regarding the theme "strengthening of nursing and midwifery." The resolutions on the theme "nursing and midwifery" were included, whose titles were available and whose full texts were accessed, excluding those on general health themes. The key words used were resolutions, strengthening, and nursing and midwifery. Among the 20 resolutions found, 12 were selected, adopted between 1948 and 2013, in accordance with the study inclusion criteria. The data were interpreted using thematic qualitative analysis, identifying and grouping the data in categories related to the study theme. Based on the content analysis of the 12 resolutions studied, three thematic categories were defined: "nursing and midwifery in primary health"; "role of nursing and midwifery in health for all"; and "nurses and midwives' professional training." Based on the categories, the evolution in the strengthening of nursing and midwifery was demonstrated through the initiatives and resolutions approved by WHA, highlighting the importance of nurses and midwives as multiprofessional health team members and their fundamental role in the improvements of the health system. Therefore, in accordance with the needs of each country, the member states can implement strategies presented by the WHA resolutions to strengthen nursing and midwifery services. This study has relevance for the development of health policies considering the relevant contributions of nurses and midwives to healthcare systems and services, based on the analysis of WHO resolutions involving these professions. © 2015 Sigma Theta Tau International.

VizieR Online Data Catalog: Absolute polarimetry observations of 33 pulsars (Force+, 2015)

NASA Astrophysics Data System (ADS)

Force, M. M.; Demorest, P.; Rankin, J. M.

2017-11-01

The observations were carried out in the summer of 2011 using the 100-m Robert C. Byrd GBT and the Green Bank Ultimate Pulsar Processing Instrument (GUPPI) in coherent filterbank mode. Full-Stokes spectra were acquired in an 800 MHz bandwidth centred at 1500 MHz radio frequency; the ~1200-1300 MHz airport radar analogue filter was used, resulting in a ~700 MHz effective bandwidth. The filterbank frequency resolution was 1.5 MHz, or 512 channels across the full band. (2 data files).

Enhancing resolution and contrast in second-harmonic generation microscopy using an advanced maximum likelihood estimation restoration method

NASA Astrophysics Data System (ADS)

Sivaguru, Mayandi; Kabir, Mohammad M.; Gartia, Manas Ranjan; Biggs, David S. C.; Sivaguru, Barghav S.; Sivaguru, Vignesh A.; Berent, Zachary T.; Wagoner Johnson, Amy J.; Fried, Glenn A.; Liu, Gang Logan; Sadayappan, Sakthivel; Toussaint, Kimani C.

2017-02-01

Second-harmonic generation (SHG) microscopy is a label-free imaging technique to study collagenous materials in extracellular matrix environment with high resolution and contrast. However, like many other microscopy techniques, the actual spatial resolution achievable by SHG microscopy is reduced by out-of-focus blur and optical aberrations that degrade particularly the amplitude of the detectable higher spatial frequencies. Being a two-photon scattering process, it is challenging to define a point spread function (PSF) for the SHG imaging modality. As a result, in comparison with other two-photon imaging systems like two-photon fluorescence, it is difficult to apply any PSF-engineering techniques to enhance the experimental spatial resolution closer to the diffraction limit. Here, we present a method to improve the spatial resolution in SHG microscopy using an advanced maximum likelihood estimation (AdvMLE) algorithm to recover the otherwise degraded higher spatial frequencies in an SHG image. Through adaptation and iteration, the AdvMLE algorithm calculates an improved PSF for an SHG image and enhances the spatial resolution by decreasing the full-width-at-halfmaximum (FWHM) by 20%. Similar results are consistently observed for biological tissues with varying SHG sources, such as gold nanoparticles and collagen in porcine feet tendons. By obtaining an experimental transverse spatial resolution of 400 nm, we show that the AdvMLE algorithm brings the practical spatial resolution closer to the theoretical diffraction limit. Our approach is suitable for adaptation in micro-nano CT and MRI imaging, which has the potential to impact diagnosis and treatment of human diseases.

Regional model simulations of New Zealand climate

NASA Astrophysics Data System (ADS)

Renwick, James A.; Katzfey, Jack J.; Nguyen, Kim C.; McGregor, John L.

1998-03-01

Simulation of New Zealand climate is examined through the use of a regional climate model nested within the output of the Commonwealth Scientific and Industrial Research Organisation nine-level general circulation model (GCM). R21 resolution GCM output is used to drive a regional model run at 125 km grid spacing over the Australasian region. The 125 km run is used in turn to drive a simulation at 50 km resolution over New Zealand. Simulations with a full seasonal cycle are performed for 10 model years. The focus is on the quality of the simulation of present-day climate, but results of a doubled-CO2 run are discussed briefly. Spatial patterns of mean simulated precipitation and surface temperatures improve markedly as horizontal resolution is increased, through the better resolution of the country's orography. However, increased horizontal resolution leads to a positive bias in precipitation. At 50 km resolution, simulated frequency distributions of daily maximum/minimum temperatures are statistically similar to those of observations at many stations, while frequency distributions of daily precipitation appear to be statistically different to those of observations at most stations. Modeled daily precipitation variability at 125 km resolution is considerably less than observed, but is comparable to, or exceeds, observed variability at 50 km resolution. The sensitivity of the simulated climate to changes in the specification of the land surface is discussed briefly. Spatial patterns of the frequency of extreme temperatures and precipitation are generally well modeled. Under a doubling of CO2, the frequency of precipitation extremes changes only slightly at most locations, while air frosts become virtually unknown except at high-elevation sites.

How cryo‐electron microscopy and X‐ray crystallography complement each other

PubMed Central

Wang, Jia‐Wei

2016-01-01

Abstract With the ability to resolve structures of macromolecules at atomic resolution, X‐ray crystallography has been the most powerful tool in modern structural biology. At the same time, recent technical improvements have triggered a resolution revolution in the single particle cryo‐EM method. While the two methods are different in many respects, from sample preparation to structure determination, they both have the power to solve macromolecular structures at atomic resolution. It is important to understand the unique advantages and caveats of the two methods in solving structures and to appreciate the complementary nature of the two methods in structural biology. In this review we provide some examples, and discuss how X‐ray crystallography and cryo‐EM can be combined in deciphering structures of macromolecules for our full understanding of their biological mechanisms. PMID:27543495

How cryo-electron microscopy and X-ray crystallography complement each other.

PubMed

Wang, Hong-Wei; Wang, Jia-Wei

2017-01-01

With the ability to resolve structures of macromolecules at atomic resolution, X-ray crystallography has been the most powerful tool in modern structural biology. At the same time, recent technical improvements have triggered a resolution revolution in the single particle cryo-EM method. While the two methods are different in many respects, from sample preparation to structure determination, they both have the power to solve macromolecular structures at atomic resolution. It is important to understand the unique advantages and caveats of the two methods in solving structures and to appreciate the complementary nature of the two methods in structural biology. In this review we provide some examples, and discuss how X-ray crystallography and cryo-EM can be combined in deciphering structures of macromolecules for our full understanding of their biological mechanisms. © 2016 The Protein Society.

Magnified hard x-ray microtomography: toward tomography with submicron resolution

NASA Astrophysics Data System (ADS)

Schroer, Christian G.; Benner, Boris; Guenzler, Til F.; Kuhlmann, Marion; Lengeler, Bruno; Rau, Christoph; Weitkamp, Timm; Snigirev, Anatoly A.; Snigireva, Irina

2002-01-01

Parabolic compound refractive lenses (PCRLs) are high quality imaging optics for hard x-rays that can be used as an objective lens in a new type of hard x-ray full field microscope. Using an aluminium PCRL, this new type of microscope has been shown to have a resolution of 350 nm. Further improvement of the resolution down to 50 nm can be expected using beryllium as a lens material. The large depth of field (several mm) of the microscope results in sharp projection images for samples that fit into the field of view of about 300 micrometers. This allows to combine magnified imaging with tomographic techniques. First results of magnified microtomography are shown. Contrast formation in the microscope and the consequences for tomographic reconstruction are discussed. An outlook on further developments is given.

4D electron tomography.

PubMed

Kwon, Oh-Hoon; Zewail, Ahmed H

2010-06-25

Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a movie of the object in motion, thus enabling studies of nonequilibrium structures and transient processes. The method was demonstrated using carbon nanotubes of a bracelet-like ring structure for which 4D tomograms display different modes of motion, such as breathing and wiggling, with resonance frequencies up to 30 megahertz. Applications can now make use of the full space-time range with the nanometer-femtosecond resolution of ultrafast electron tomography.

4D Electron Tomography

NASA Astrophysics Data System (ADS)

Kwon, Oh-Hoon; Zewail, Ahmed H.

2010-06-01

Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a movie of the object in motion, thus enabling studies of nonequilibrium structures and transient processes. The method was demonstrated using carbon nanotubes of a bracelet-like ring structure for which 4D tomograms display different modes of motion, such as breathing and wiggling, with resonance frequencies up to 30 megahertz. Applications can now make use of the full space-time range with the nanometer-femtosecond resolution of ultrafast electron tomography.

High-resolution, continuous field-of-view (FOV), non-rotating imaging system

NASA Technical Reports Server (NTRS)

Huntsberger, Terrance L. (Inventor); Stirbl, Robert C. (Inventor); Aghazarian, Hrand (Inventor); Padgett, Curtis W. (Inventor)

2010-01-01

A high resolution CMOS imaging system especially suitable for use in a periscope head. The imaging system includes a sensor head for scene acquisition, and a control apparatus inclusive of distributed processors and software for device-control, data handling, and display. The sensor head encloses a combination of wide field-of-view CMOS imagers and narrow field-of-view CMOS imagers. Each bank of imagers is controlled by a dedicated processing module in order to handle information flow and image analysis of the outputs of the camera system. The imaging system also includes automated or manually controlled display system and software for providing an interactive graphical user interface (GUI) that displays a full 360-degree field of view and allows the user or automated ATR system to select regions for higher resolution inspection.

Role of coherence in microsphere-assisted nanoscopy

NASA Astrophysics Data System (ADS)

Perrin, Stephane; Lecler, Sylvain; Leong-Hoi, Audrey; Montgomery, Paul C.

2017-06-01

The loss of the information, due to the diffraction and the evanescent waves, limits the resolving power of classical optical microscopy. In air, the lateral resolution of an optical microscope can approximated at half of the wavelength using a low-coherence illumination. Recently, several methods have been developed in order to overcome this limitation and, in 2011, a new far-field and full-field imaging technique was proposed where a sub-diffraction-limit resolution has been achieved using a transparent microsphere. In this article, the phenomenon of super-resolution using microsphere-assisted microscopy is analysed through rigorous electro-magnetic simulations. The performances of the imaging technique are estimated as function of optical and geometrical parameters. Furthermore, the role of coherence is introduced through the temporal coherence of the light source and the phase response of the object.