Science.gov

Sample records for image cloud patterns

  1. Cloud pattern prediction from geostationary meteorological satellite images for solar energy forecasting

    NASA Astrophysics Data System (ADS)

    Cros, S.; Sbastien, N.; Liandrat, O.; Schmutz, N.

    2014-10-01

    Surface solar radiation forecasting permits to predict photovoltaic plant production for a massive and safe integration of solar energy into the electric network. For short-term forecasts (intra-day), methods using images from meteorological geostationary satellites are more suitable than numerical weather prediction models. Forecast schemes consist in assessing cloud motion vectors and in extrapolating cloud patterns from a given satellite image in order to predict cloud cover state above a PV plant. Atmospheric motion vectors retrieval techniques have been studied for several decades in order to improve weather forecasts. However, solar energy forecasting requires the extraction of cloud motion vectors on a finer spatial- and time-resolution than those provided for weather forecast applications. Even if motion vector retrieval is a wide research field in image processing related topics, only block-matching techniques are operationally used for solar energy forecasts via satellite images. In this paper, we propose two motion vectors extraction methods originating from video compression techniques (correlation phase and optical flow methods). We implemented them on a 6-day dataset of Meteosat-10 satellite diurnal images. We proceeded to cloud pattern extrapolation and compared predicted cloud maps against actual ones at different time horizons from 15 minutes to 4 hours ahead. Forecast scores were compared to the state-of-the-art (block matching) method. Correlation phase methods do not outperform block-matching but their computation time is about 25 times shorter. Optical flow based method outperforms all the methods with a satisfactory time computing.

  2. Global patterns in cloud forms on Mars

    NASA Astrophysics Data System (ADS)

    French, R. G.; Gierasch, P. J.; Popp, B. D.; Yerdon, R. J.

    1981-02-01

    Mariner 9 images and all Viking orbiter images through July 1979 were searched for cloud forms. A computer-accessible catalog was assembled, consisting of a classification of cloud type (lee wave, for example) and properties (directionality, wavelength, for example). Lee wave directionality shows a pattern and seasonal variation at high latitudes which is consistent with predictions of theoretical modeling. Fog and haze occurrence shows no obvious correlation with water abundance or any other simple causal factor. Lee waves are rare at equatorial latitudes. Plumes (probably dust) occur preferentially at locations where strong boundary layer convection is expected.

  3. 4-D display of satellite cloud images

    NASA Technical Reports Server (NTRS)

    Hibbard, William L.

    1987-01-01

    A technique has been developed to display GOES satellite cloud images in perspective over a topographical map. Cloud heights are estimated using temperatures from an infrared (IR) satellite image, surface temperature observations, and a climatological model of vertical temperature profiles. Cloud levels are discriminated from each other and from the ground using a pattern recognition algorithm based on the brightness variance technique of Coakley and Bretherton. The cloud regions found by the pattern recognizer are rendered in three-dimensional perspective over a topographical map by an efficient remap of the visible image. The visible shades are mixed with an artificial shade based on the geometry of the cloud-top surface, in order to enhance the texture of the cloud top.

  4. Determine precipitation rates from visible and infrared satellite images of clouds by pattern recognition technique. Progress Report, 1 Jul. 1985 - 31 Mar. 1987 Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Weinman, James A.; Garan, Louis

    1987-01-01

    A more advanced cloud pattern analysis algorithm was subsequently developed to take the shape and brightness of the various clouds into account in a manner that is more consistent with the human analyst's perception of GOES cloud imagery. The results of that classification scheme were compared with precipitation probabilities observed from ships of opportunity off the U.S. east coast to derive empirical regressions between cloud types and precipitation probability. The cloud morphology was then quantitatively and objectively used to map precipitation probabilities during two winter months during which severe cold air outbreaks were observed over the northwest Atlantic. Precipitation probabilities associated with various cloud types are summarized. Maps of precipitation probability derived from the cloud morphology analysis program for two months and the precipitation probability derived from thirty years of ship observation were observed.

  5. Cloud computing in medical imaging.

    PubMed

    Kagadis, George C; Kloukinas, Christos; Moore, Kevin; Philbin, Jim; Papadimitroulas, Panagiotis; Alexakos, Christos; Nagy, Paul G; Visvikis, Dimitris; Hendee, William R

    2013-07-01

    Over the past century technology has played a decisive role in defining, driving, and reinventing procedures, devices, and pharmaceuticals in healthcare. Cloud computing has been introduced only recently but is already one of the major topics of discussion in research and clinical settings. The provision of extensive, easily accessible, and reconfigurable resources such as virtual systems, platforms, and applications with low service cost has caught the attention of many researchers and clinicians. Healthcare researchers are moving their efforts to the cloud, because they need adequate resources to process, store, exchange, and use large quantities of medical data. This Vision 20/20 paper addresses major questions related to the applicability of advanced cloud computing in medical imaging. The paper also considers security and ethical issues that accompany cloud computing. PMID:23822402

  6. Automated Recognition of Oceanic Cloud Patterns. Part I: Methodology and Application to Cloud Climatology.

    NASA Astrophysics Data System (ADS)

    Garand, Louis

    1988-01-01

    A scheme is presented for the automated classification of oceanic cloud patterns. The 20 cloud classes reflect the rich variety of morphologies that are detectable from space. A training set is defined by 2000 samples of size 128 128 km taken from GOES visible and infrared images over the western Atlantic in February 1984. Class discrimination is obtained from 13 features representing height, albedo, shape and multilayering characteristics of the cloud fields. Two features derived from the two-dimensional power spectrum of the visible images proved essential for the detection of directional patterns (cloud `streets or rolls) and open cells. Based on the assumption of multinormal distributions of the features, a simple classification algorithm is developed. The generation of artificial samples yields a theoretical separability of 97% while the actual separability obtained on the training set is 95%. From 1020 independent samples, the separate verification of three expert nephanalysts indicates strict accuracy in 79% of the cases while there is agreement with their first or second choice in 89% of the cases.The cloud climatology is compared in 20 classes for January and February 1984. In agreement with available climatology, multilayered cloud fields are observed 42% of the time. The cloud fraction maps are also compared with the observed fields from ships.

  7. High S/N Keck and Gemini AO imaging of Uranus during 2012-2014: New cloud patterns, increasing activity, and improved wind measurements

    NASA Astrophysics Data System (ADS)

    Sromovsky, L. A.; de Pater, I.; Fry, P. M.; Hammel, H. B.; Marcus, P.

    2015-09-01

    We imaged Uranus in the near infrared from 2012 into 2014, using the Keck/NIRC2 camera and Gemini/NIRI camera, both with adaptive optics. We obtained exceptional signal to noise ratios by averaging 8-16 individual exposures in a planet-fixed coordinate system. These noise-reduced images revealed many low-contrast discrete features and large scale cloud patterns not seen before, including scalloped waveforms just south of the equator, and an associated transverse ribbon wave near 6°S. In all three years numerous small (600-700 km wide) and mainly bright discrete features were seen within the north polar region (north of about 55°N). Two small dark spots with bright companions were seen at middle latitudes. Over 850 wind measurements were made, the vast majority of which were in the northern hemisphere. Winds at high latitudes were measured with great precision, revealing an extended region of solid body rotation between 62°N and at least 83°N, at a rate of 4.08 ± 0.015°/h westward relative to the planet's interior (radio) rotation of 20.88°/h westward. Near-equatorial speeds measured with high accuracy give different results for waves and small discrete features, with eastward drift rates of 0.4°/h and 0.1°/h respectively. The region of polar solid body rotation is a close match to the region of small-scale polar cloud features, suggesting a dynamical relationship. The winds from prior years and those from 2012-2014 are consistent with a mainly symmetric wind profile up to middle latitudes, with a small asymmetric component of ∼0.09°/h peaking near ±30°, and about 60% greater amplitude if only prior years are included, suggesting a declining mid-latitude asymmetry. While winds at high southern latitudes (50-90°S) are unconstrained by groundbased observations, a recent reanalysis of 1986 Voyager 2 observations by Karkoschka (Karkoschka [2015]. Icarus 250, 294-307) has revealed an extremely large north-south asymmetry in this region, which might be seasonal. Greatly increased activity was seen in 2014, including the brightest ever feature seen in K‧ images (de Pater et al. [2015]. Icarus 252, 121-128), as well as other significant features, some of which had long lives. Over the 2012-2014 period we identified six persistent discrete features. Three were tracked for more than 2 years, two more for more than 1 year, and one for at least 5 months and continuing. Several drifted in latitude towards the equator, and others appeared to exhibit latitudinal oscillations with long periods. We found two pairs of long-lived features that survived multiple passages within their own diameters of each other. Zonally averaged cloud patterns were found to persist over 2012-2014. When averaged over longitude, there is a brightness variation with latitude from 55°N to the pole that is similar to effective methane mixing ratio variations with latitude derived from 2012 STIS observations (Sromovsky et al. [2014]. Icarus 238, 137-155).

  8. Comparison of IR and Visible Cloud Imagers

    NASA Astrophysics Data System (ADS)

    Mandeville, W.; McLaughlin, T.; Bygren, S.; Randell, C.

    This paper presents a comparison between the Infrared Cloud Imager (IRCI) used at Ground-based Electro-Optical Deep Space Surveillance (GEODSS) sites and the Visible Cloud Imager (VCI) developed using a COTS all-sky camera. The cloud imagers are used to create exclusion maps for GEODSS observations based on detected cloud locations. Excluding observation attempts in obscured areas of the sky is done to improve the allocation of sensor resources. Estimates are made for atmospheric extinction across the entire sky by comparing known star brightness to measured brightness. Data for the comparison were collected at the GEODSS test site located in Yoder, Colorado for a variety of cloud conditions.

  9. Pattern recognition of satellite cloud imagery for improved weather prediction

    NASA Technical Reports Server (NTRS)

    Gautier, Catherine; Somerville, Richard C. J.; Volfson, Leonid B.

    1986-01-01

    The major accomplishment was the successful development of a method for extracting time derivative information from geostationary meteorological satellite imagery. This research is a proof-of-concept study which demonstrates the feasibility of using pattern recognition techniques and a statistical cloud classification method to estimate time rate of change of large-scale meteorological fields from remote sensing data. The cloud classification methodology is based on typical shape function analysis of parameter sets characterizing the cloud fields. The three specific technical objectives, all of which were successfully achieved, are as follows: develop and test a cloud classification technique based on pattern recognition methods, suitable for the analysis of visible and infrared geostationary satellite VISSR imagery; develop and test a methodology for intercomparing successive images using the cloud classification technique, so as to obtain estimates of the time rate of change of meteorological fields; and implement this technique in a testbed system incorporating an interactive graphics terminal to determine the feasibility of extracting time derivative information suitable for comparison with numerical weather prediction products.

  10. IRAS images of nearby dark clouds

    NASA Technical Reports Server (NTRS)

    Wood, Douglas O. S.; Myers, Philip C.; Daugherty, Debra A.

    1994-01-01

    We have investigated approximately 100 nearby molecular clouds using the extensive, all-sky database of IRAS. The clouds in this study cover a wide range of physical properties including visual extinction, size, mass, degree of isolation, homogeneity and morphology. IRAS 100 and 60 micron co-added images were used to calculate the 100 micron optical depth of dust in the clouds. These images of dust optical depth compare very well with (12)CO and (13)CO observations, and can be related to H2 column density. From the optical depth images we locate the edges of dark clouds and the dense cores inside them. We have identified a total of 43 `IRAS clouds' (regions with A(sub v) greater than 2) which contain a total of 255 `IRAS cores' (regions with A(sub v) greater than 4) and we catalog their physical properties. We find that the clouds are remarkably filamentary, and that the cores within the clouds are often distributed along the filaments. The largest cores are usually connected to other large cores by filaments. We have developed selection criteria to search the IRAS Point Source Catalog for stars that are likely to be associated with the clouds and we catalog the IRAS sources in each cloud or core. Optically visible stars associated with the clouds have been identified from the Herbig and Bell catalog. From these data we characterize the physical properties of the clouds including their star-formation efficiency.

  11. Retrieval algorithms for cloud motion from ground-based images

    NASA Astrophysics Data System (ADS)

    Bakalova, Kalinka

    We present the preliminary results of a project, focused on obtaining information about the velocity and direction of motion of air masses by means of ground-based measurements of visible cloud motion. This information can be used in short-term local weather forecast and is helpful in studies of the dynamics of the physical processes in clouds. We report the recent progress in the development of algorithms and tools for retrieving the three-dimensional field of vectors of velocity of cloud motion from time series of ground-based digital images. The visible motion of a cloud is the compound effect of the translational drift of the cloud as a whole with the velocity of the adjacent air masses, and of deformations due to the physical processes in the atmosphere. Because of the continuous changes of shape, extracting the translational component in the displacement of a cloud from a series of consecutive images is a highly non-trivial problem. Our approach consists in selecting a set of characteristic reference patterns of the cloud on the first image of the series, tracking them on the subsequent images, and evaluating this way the individual displacement of each reference pattern. Specific algorithms are being developed for the optimal choice of the reference patterns on the starting image and the recognition of these patterns on the subsequent images, depending on the type of the observed cloud. For clouds with low contrast or no edges, such as Stratus, Nimbostratus and Stratocumulus, implementations of the Optical Flow method are under development. For clouds with distinct contours, such as Cumulus and Altocumulus, the edges are decomposed into one-dimensional curvilinear patterns. To reduce the uncertainties, a multi-parametric model of the transformations of the cloud shape between images is defined next which, besides parallel transport, also involves dilatation, rotation, and possibly some local deformations. The parameters of the model are calculated from the individual displacements of the patterns by a least-square fit. What is obtained this way is a smooth approximation to the two-dimensional field of angular velocities of the cloud surface as seen from the observer's position. The three-dimensional vectors of velocity of the cloud are calculated by combining the results of multiple synchronous observations from distant sites. Prior to be put together, the data from different observers are corrected for optical distortion. We analyse the various sources of uncertainty of the calculated velocities of air masses, related to inaccuracy of the digital images, to identification errors in tracking the reference patterns on the series of images and to triangulation. We show that external telemetric information about the distance to the observed clouds may reduce the uncertainty of the results. We also discuss the optimal choice of the time interval between consecutive images as a compromise between the increasing requirements for computational power and the higher efficiency of the pattern recognition methods at shorter time intervals. The work is partially supported by the Bulgarian NFSR under contract NZ-1414/04.

  12. Patterns of Diurnal Marine Stratocumulus Cloud Fraction Variability

    SciTech Connect

    Burleyson, Casey D.; Yuter, S. E.

    2015-04-01

    The spatial patterns of subtropical marine stratocumulus cloud fraction variability on diurnal time scales are examined using high temporal resolution cloud masks based on 30-min 4 km x 4 km geosynchronous IR data for the period 2003-2010. This data set permits comparison of low cloud fraction variability characteristics among the three marine stratocumulus regions in the southeast Pacific, southeast Atlantic and northeast Pacific. In all three regions, the largest diurnal cycles and earliest time of cloud break up occur on the edges of the cloud field where cloud fractions are in general lower. During the peak season of cloudiness in the southeast Pacific and southeast Atlantic the amplitude of the diurnal cycle on the edges of the cloud deck was greater than 40%, more than double the value found in the center of each cloud deck. The rate at which the cloud breaks up during the day is closely tied to starting cloud fraction at dawn and the shortwave radiative flux. The maximum rate of cloud breakup occurs near 1200 LT. Cloud fraction begins to increase at 1600 LT (before the sun sets) and reaches its maximum value just before dawn. The diurnal cycle characteristics of the southeast Pacific and southeast Atlantic marine stratocumulus cloud decks are more similar to each other than to those in the northeast Pacific. The northeast Pacific cloud deck has weaker diurnal variation, slower rates of cloud breakup during the day for a given cloud fraction at dawn, and higher probabilities for cloud break up overnight.

  13. CEDIMS: cloud ethical DICOM image Mojette storage

    NASA Astrophysics Data System (ADS)

    Gudon, Jeanpierre; Evenou, Pierre; Terv, Pierre; David, Sylvain; Branger, Jrome

    2012-02-01

    Dicom images of patients will necessarily been stored in Clouds. However, ethical constraints must apply. In this paper, a method which provides the two following conditions is presented: 1) the medical information is not readable by the cloud owner since it is distributed along several clouds 2) the medical information can be retrieved from any sufficient subset of clouds In order to obtain this result in a real time processing, the Mojette transform is used. This paper reviews the interesting features of the Mojette transform in terms of information theory. Since only portions of the original Dicom files are stored into each cloud, their contents are not reachable. For instance, we use 4 different public clouds to save 4 different projections of each file, with the additional condition that any 3 over 4 projections are enough to reconstruct the original file. Thus, even if a cloud is unavailable when the user wants to load a Dicom file, the other 3 are giving enough information for real time reconstruction. The paper presents an implementation on 3 actual clouds. For ethical reasons, we use a Dicom image spreaded over 3 public clouds to show the obtained confidentiality and possible real time recovery.

  14. Changes in Climate Variables: Contribution of Cloud Types to Global and Regional Cloud Patterns

    NASA Astrophysics Data System (ADS)

    Dim, J. R.; Murakami, H.; Nakajima, T. Y.

    2010-12-01

    Temporal and spatial variations in cloud patterns can impact the Earth's energy balance and other climate variables. The long-term change of clouds’ behaviour and the contribution of various cloud types to the cloud patterns are studied through the analyses of cloud amounts’ distributions and variations as derived from the National Oceanic and Atmospheric Administration-Advanced Very-High-Resolution Radiometer (NOAA-AVHRR). Daytime cloud data from 25 years (1982-2006) of observations are examined and the results are discussed at the global and regional scales. The dataset used is acquired from six consecutive satellite series. Orbital drifts effects due to the late equatorial time crossing of these satellites are detectable on the cloud quantities retrieved. To obtain reliable long-term cloud trends, these drifts effects should be removed. The correction approach applied for the cloud quantities analyzed in this study is based on the good performance of the empirical mode decomposition (EMD) method in the separation and extraction of the seasonal and inter-annual components of the cloud amounts derived from each satellite, and the correlation of these components with solar zenith angle (expression of the satellite drift) similar components. The results obtained show a quantifiable improvement of the quality of each NOAA satellite’s derived cloud patterns as well as that of the whole series of data; and, more similarities with other climate variables and satellite cloud climatology analyses such as the International Satellite Cloud Climatology Project (ISCCP). The examination of the overall cloud trends show that there is a slight (-0.040%/year) to a strong (-0.133%/year) decrease in the global and land cloud trends respectively. This decrease is mostly the result of the strong negative contribution of the stratocumulus clouds to the overall trends. For the ocean clouds, a slight increase (0.04%/year) was noticed and, this appears to be mainly driven by the high increase of cirrus clouds overwhelming the still remarkable decrease of stratocumulus clouds.

  15. Research on removing cloud from optical images

    NASA Astrophysics Data System (ADS)

    Zhu, Xifang; Wu, Feng

    2011-11-01

    This paper proposes a novel algorithm for distinguishing scenery information from cloud noise in the low-level and high-level detail coefficients using the wavelet decomposition. Also this paper shows approximate coefficients only containing the scenery information, and high-level detail coefficients mainly including the cloud noise and the partial scenery information. Usually cloud is brighter than the scene illumination. Therefore the appropriate brightness threshold is setup for processing high-level detail coefficients aimed at the elimination of cloud noise. Simultaneously to remove the residual cloud at the low frequency component and improve the clarity of the scenery image, the paper further decomposes the detail coefficients based on the frequency. For example, the low-level detail coefficients are decomposed further once or twice by wavelet packets. So we can remove remaining cloud decomposed effectively at the low frequency, and through assigning the appropriate weight to the detail coefficient, achieve the goal for enhancing scenery information and improving the image clarity. Considering influence of the parameter changes on the algorithm performance, we use the entropy as the criterion for choosing the optimal parameters step by step. We have demonstrated that this algorithm using the entropy as criterion is feasible. The experimental results are superior to homomorphism filtering and the Retinex algorithm in many aspects.

  16. Male pattern baldness (image)

    MedlinePLUS

    Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than by looking ...

  17. Spatial and Temporal Patterns of Aerosol-Cloud Interactions

    NASA Astrophysics Data System (ADS)

    Fuchs, Julia; Cermak, Jan

    2014-05-01

    This study determines the spatial and temporal distribution of regions with frequent aerosol-cloud interactions (aci) and identifies their meteorological determinants based on CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) and ECMWF (European Centre for Medium-Range Weather Forecasts) data products. Atmospheric aerosols influence the microphysical structure of clouds, while both also respond to meteorological conditions. The potential radiative adjustments to changes in a cloud system associated with aerosol-cloud interactions are grouped and termed as effective radiative forcing due to aerosol-cloud interactions (ERFaci). It is difficult to distinguish, to what extent radiative forcing and precipitation patterns of clouds are a result of cloud feedbacks to aerosols or the existing meteorological conditions. A complete understanding of aerosol-cloud-meteorology interactions is crucial as the uncertainty range of ERFaci in climate change modeling could be significantly reduced. In the present study it is suggested that presence of hydrated aerosols is an implication for aci. Knowledge of their vertical and horizontal distribution and frequency over the globe would be important for understanding ERFaci. To identify regions with aerosol-cloud transitions the CAD score (cloud-aerosol discrimination) of the CALIOP (Cloud-Aerosol LIdar with Orthogonal Polarization) instrument on the CALIPSO satellite is used. It separates aerosols and clouds according to the probability distribution functions of 5 parameters (attenuated backscatter, total color ratio, volume depolarization ratio, altitude and latitude) and assigns the likelihood of cloud or aerosol presence. This parameter is used to calculate relative frequencies of aci on a global scale from 2006 to 2013.

  18. UV image processing to detect diffuse clouds

    NASA Astrophysics Data System (ADS)

    Armengot, M.; Gmez de Castro, A. I.; Lpez-Santiago, J.; Snchez-Doreste, N.

    2015-05-01

    The presence of diffuse clouds along the Galaxy is under consideration as far as they are related to stellar formation and their physical properties are not well understood. The signal received from most of these structures in the UV images is minimal compared to the point sources. The presence of noise in these images makes hard the analysis because the Signal-to-Noise ratio is proportionally much higher in these areas. However, the digital processing of the images shows that it is possible to enhance and target these clouds. Typically, this kind of treatment is done on purpose for specific research areas and the Astrophysicist's work depends on the computer tools and its possibilities for enhancing a particular area based on a prior knowledge. Automating this step is the goal of our work to make easier the study of these structures in UV images. In particular we have used the GALEX survey images in the aim of learning to automatically detect such clouds and be able of unsupervised detection and graphic enhancement to log them. Our experiments show the existence of some evidences in the UV images that allow the systematic computing and open the chance to generalize the algorithm to find these structures in universe areas where they have not been recorded yet.

  19. First image of clouds over Mars

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first image ever taken from the surface of Mars of an overcast sky. Featured are stratus clouds coming from the northeast at about 15 miles per hour (6.7 meters/second) at an approximate height of ten miles (16 kilometers) above the surface. The 'you are here' notation marks where Earth was situated in the sky at the time the image was taken. Scientists had hoped to see Earth in this image, but the cloudy conditions prevented a clear viewing. Similar images will be taken in the future with the hope of capturing a view of Earth. From Mars, Earth would appear as a tiny blue dot as a star would appear to an Earthbound observer. Pathfinder's imaging system will not be able to resolve Earth's moon. The clouds consist of water ice condensed on reddish dust particles suspended in the atmosphere. Clouds on Mars are sometimes localized and can sometimes cover entire regions, but have not yet been observed to cover the entire planet. The image was taken about an hour and forty minutes before sunrise by the Imager for Mars Pathfinder (IMP) on Sol 16 at about ten degrees up from the eastern Martian horizon.

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

  20. Pattern recognition analysis of polar clouds during summer and winter

    NASA Technical Reports Server (NTRS)

    Ebert, Elizabeth E.

    1992-01-01

    A pattern recognition algorithm is demonstrated which classifies eighteen surface and cloud types in high-latitude AVHRR imagery based on several spectral and textural features, then estimates the cloud properties (fractional coverage, albedo, and brightness temperature) using a hybrid histogram and spatial coherence technique. The summertime version of the algorithm uses both visible and infrared data (AVHRR channels 1-4), while the wintertime version uses only infrared data (AVHRR channels 3-5). Three days of low-resolution AVHRR imagery from the Arctic and Antarctic during January and July 1984 were analyzed for cloud type and fractional coverage. The analysis showed significant amounts of high cloudiness in the Arctic during one day in winter. The Antarctic summer scene was characterized by heavy cloud cover in the southern ocean and relatively clear conditions in the continental interior. A large region of extremely low brightness temperatures in East Antarctica during winter suggests the presence of polar stratospheric cloud.

  1. Recognition methods on cloud amount, movement of clouds, and rain clouds for rainfall prediction using whole sky images

    NASA Astrophysics Data System (ADS)

    Fujinuma, Kazuma; Arai, Masayuki

    2014-04-01

    The final target of our research is to develop a system for forecasting local concentrated heavy rain, such as guerrilla rainstorms, by using whole sky images taken on the ground. To construct this system, this paper proposes the following recognition methods: cloud amount, movement of clouds, and rain clouds. The experimental results show that red/blue (R/B) values are efficient for measuring the cloud amount. However, using the gravity of images and the difference among time-sequenced images is insufficient to recognize the movement of clouds and does not correlate well with the R/B values and rain.

  2. An efficient framework for modeling clouds from Landsat8 images

    NASA Astrophysics Data System (ADS)

    Yuan, Chunqiang; Guo, Jing

    2015-03-01

    Cloud plays an important role in creating realistic outdoor scenes for video game and flight simulation applications. Classic methods have been proposed for cumulus cloud modeling. However, these methods are not flexible for modeling large cloud scenes with hundreds of clouds in that the user must repeatedly model each cloud and adjust its various properties. This paper presents a meteorologically based method to reconstruct cumulus clouds from high resolution Landsat8 satellite images. From these input satellite images, the clouds are first segmented from the background. Then, the cloud top surface is estimated from the temperature of the infrared image. After that, under a mild assumption of flat base for cumulus cloud, the base height of each cloud is computed by averaging the top height for pixels on the cloud edge. Then, the extinction is generated from the visible image. Finally, we enrich the initial shapes of clouds using a fractal method and represent the recovered clouds as a particle system. The experimental results demonstrate our method can yield realistic cloud scenes resembling those in the satellite images.

  3. CloudSat Image of Tropical Thunderstorms Over Africa

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1

    CloudSat image of a horizontal cross-section of tropical clouds and thunderstorms over east Africa. The red colors are indicative of highly reflective particles such as water (rain) or ice crystals, which the blue indicates thinner clouds (such as cirrus). The flat green/blue lines across the bottom represent the ground signal. The vertical scale on the CloudS at Cloud Profiling Radar image is approximately 30 kilometers (19 miles). The brown line below the image indicates the relative elevation of the land surface. The inset image shows the CloudSat track relative to a Moderate Resolution Imaging Spectroradiometer (MODIS) visible image taken at nearly the same time.

  4. A cloud-based medical image repository

    NASA Astrophysics Data System (ADS)

    Maeder, Anthony J.; Planitz, Birgit M.; El Rifai, Diaa

    2012-02-01

    Many widely used digital medical image collections have been established but these are generally used as raw data sources without related image analysis toolsets. Providing associated functionality to allow specific types of operations to be performed on these images has proved beneficial in some cases (e.g. brain image registration and atlases). However, toolset development to provide generic image analysis functions on medical images has tended to be ad hoc, with Open Source options proliferating (e.g. ITK). Our Automated Medical Image Collection Annotation (AMICA) system is both an image repository, to which the research community can contribute image datasets, and a search/retrieval system that uses automated image annotation. AMICA was designed for the Windows Azure platform to leverage the flexibility and scalability of the cloud. It is intended that AMICA will expand beyond its initial pilot implementation (for brain CT, MR images) to accommodate a wide range of modalities and anatomical regions. This initiative aims to contribute to advances in clinical research by permitting a broader use and reuse of medical image data than is currently attainable. For example, cohort studies for cases with particular physiological or phenotypical profiles will be able to source and include enough cases to provide high statistical power, allowing more individualised risk factors to be assessed and thus allowing screening and staging processes to be optimised. Also, education, training and credentialing of clinicians in image interpretation, will be more effective because it will be possible to select instances of images with specific visual aspects, or correspond to types of cases where reading performance improvement is desirable.

  5. MISR Stereo Imaging Distinguishes Smoke from Cloud

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These views of western Alaska were acquired by MISR on June 25, 2000 during Terra orbit 2775. The images cover an area of about 150 kilometers x 225 kilometers, and have been oriented with north to the left. The left image is from the vertical-viewing (nadir) camera, whereas the right image is a stereo 'anaglyph' that combines data from the forward-viewing 45-degree and 60-degree cameras. This image appears three-dimensional when viewed through red/blue glasses with the red filter over the left eye. It may help to darken the room lights when viewing the image on a computer screen.

    The Yukon River is seen wending its way from upper left to lower right. A forest fire in the Kaiyuh Mountains produced the long smoke plume that originates below and to the right of image center. In the nadir view, the high cirrus clouds at the top of the image and the smoke plume are similar in appearance, and the lack of vertical information makes them hard to differentiate. Viewing the righthand image with stereo glasses, on the other hand, demonstrates that the scene consists of several vertically-stratified layers, including the surface terrain, the smoke, some scattered cumulus clouds, and streaks of high, thin cirrus. This added dimensionality is one of the ways MISR data helps scientists identify and classify various components of terrestrial scenes.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  6. Global patterns of solar influence on high cloud cover

    NASA Astrophysics Data System (ADS)

    Dima, Mihai; Voiculescu, Mirela

    2015-10-01

    One of the main sources of uncertainty in climate projections is represented by clouds, which have a profound influence on the Earth's radiation budget through the feedbacks in which they are involved. The improvement of clouds representation in General Circulation Models relies largely on constraints derived from observations and on correct identification of processes that influence cloud formation or lifetime. Here we identify solar forced high cloud cover (HCC) patterns in reanalysis and observed data extending over the 1871-2009 period, based on their associations with known fingerprints of the same forcing on surface air temperature, sea surface temperature (SST) and sea level pressure fields. The solar influence on HCC has maximum amplitudes over the Pacific basin, where HCC anomalies are distributed in bands of alternating polarities. The colocation of the HCC and SST anomalies bands indicates a thermal influence on high clouds through convection and an amplification of the HCC anomalies by a positive feedback of long-wave fluxes, which increases the solar signal. Consistent with numerical simulations, the solar forced HCC pattern appears to be generated through a constructive interference between the so-called "top-down" and "bottom-up" mechanisms of solar influence on climate and is amplified by ocean-atmosphere positive feedbacks.

  7. Capturing and analyzing wheelchair maneuvering patterns with mobile cloud computing.

    PubMed

    Fu, Jicheng; Hao, Wei; White, Travis; Yan, Yuqing; Jones, Maria; Jan, Yih-Kuen

    2013-01-01

    Power wheelchairs have been widely used to provide independent mobility to people with disabilities. Despite great advancements in power wheelchair technology, research shows that wheelchair related accidents occur frequently. To ensure safe maneuverability, capturing wheelchair maneuvering patterns is fundamental to enable other research, such as safe robotic assistance for wheelchair users. In this study, we propose to record, store, and analyze wheelchair maneuvering data by means of mobile cloud computing. Specifically, the accelerometer and gyroscope sensors in smart phones are used to record wheelchair maneuvering data in real-time. Then, the recorded data are periodically transmitted to the cloud for storage and analysis. The analyzed results are then made available to various types of users, such as mobile phone users, traditional desktop users, etc. The combination of mobile computing and cloud computing leverages the advantages of both techniques and extends the smart phone's capabilities of computing and data storage via the Internet. We performed a case study to implement the mobile cloud computing framework using Android smart phones and Google App Engine, a popular cloud computing platform. Experimental results demonstrated the feasibility of the proposed mobile cloud computing framework. PMID:24110214

  8. Cloud Imagers Offer New Details on Earth's Health

    NASA Technical Reports Server (NTRS)

    2009-01-01

    A stunning red sunset or purple sunrise is an aesthetic treat with a scientific explanation: The colors are a direct result of the absorption or reflectance of solar radiation by atmospheric aerosols, minute particles (either solid or liquid) in the Earth s atmosphere that occur both naturally and because of human activity. At the beginning or end of the day, the Sun s rays travel farther through the atmosphere to reach an observer s eyes and more green and yellow light is scattered, making the Sun appear red. Sunset and sunrise are especially colorful when the concentration of atmospheric particles is high. This ability of aerosols to absorb and reflect sunlight is not just pretty; it also determines the amount of radiation and heat that reaches the Earth s surface, and can profoundly affect climate. In the atmosphere, aerosols are also important as nuclei for the condensation of water droplets and ice crystals. Clouds with fewer aerosols cannot form as many water droplets (called cloud particles), and consequently, do not scatter light well. In this case, more sunlight reaches the Earth s surface. When aerosol levels in clouds are high, however, more nucleation points can form small liquid water droplets. These smaller cloud particles can reflect up to 90 percent of visible radiation to space, keeping the heat from ever reaching Earth s surface. The tendency for these particles to absorb or reflect the Sun s energy - called extinction by astronomers - depends on a number of factors, including chemical composition and the humidity and temperature in the surrounding air; because cloud particles are so small, they are affected quickly by minute changes in the atmosphere. Because of this sensitivity, atmospheric scientists study cloud particles to anticipate patterns and shifts in climate. Until recently, NASA s study of atmospheric aerosols and cloud particles has been focused primarily on satellite images, which, while granting large-scale atmospheric analysis, limited scientists ability to acquire detailed information about individual particles. Now, experiments with specialized equipment can be flown on standard jets, making it possible for researchers to monitor and more accurately anticipate changes in Earth s atmosphere and weather patterns.

  9. A new thin cloud removal algorithm in single airborne image

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Fang, Junyong; Liu, Xue; Zhao, Dong; Xiao, Qing

    2014-11-01

    The application of high-resolution airborne images becomes more and more extensive. However because of the complexity of atmospheric environment, airborne remote sensing imaging process is easily affected by cloud and mist, which results in airborne image blurred or loss of information. So it is a necessary task to remove effects of cloud to get clearer images before the next application such as image registration. This paper proposes a new method of removing thin cloud cover from single airborne image. This method applies scale space transform to get scale space sequence images. Then we use difference between different levels to extract cloud area. Next, we use gray classification which represents cloud effect degree in the highest level of cloud area. Finally, we use the original image filtered by Laplacian to subtract the last step result. Compared with other thin cloud cover removal methods which include the homomorphic filtering method, wavelet transform method and mathematical morphology by visual evaluation and statistical analysis, the method proposed by this paper proves to be the most efficient way in the processing of thin cloud cover of airborne image.

  10. Martian Cloud Modeling using NIR Spectral Images

    NASA Astrophysics Data System (ADS)

    Klassen, David R.

    2007-10-01

    In the near-infrared (NIR), disentangling surface and aerosol spectral features is a difficult, iterative process. In order to be able to use radiative transfer to model clouds you need to know the surface reflection characteristics; but to get the surface reflection, you need to be able to subtract off the atmospheric spectral contribution. One way to attempt to solve this is to "simply" create a monolithic system with a large number of parameters - one for each surface component, each aerosol species, and each gas constituent. Such a multi-dimensional space is no doubt complex with large difficulties in solution uniqueness. Using ground-based NIR spectral images acquired over several oppositions from the NASA IRTF, we have been able to show that a principle components analysis is able to find two surface components without any a priori inputs [1, 2]. Further work has shown that these surface spectral components are fairly uniform across all seasons [3, 4]. Additionally, we have been able to create a radiative transfer modeling system that was previously used to calculate aphelion cloud optical depths using only the 3 ?m spectral region [5]. In this presentation I will present preliminary results from combining the radiative transfer with the recovered surface spectral signatures as inputs to measure martian cloud optical depths in the NIR. This work was supported by grants from the NASA Mars Data Analysis and the NSF-RUI programs. References: [1] Klassen, D. R. and Bell III, J. F. (2001) BAAS 33, 1069. [2] Klassen, D. R., Wark, T. J., Cugliotta, C. G. (2005) BAAS, 37, 693. [3] Klassen, D. R. and Bell III, J. F. (2003) BAAS, 35, 936. [4] Klassen, D. R. and Bell III, J. F. (2007) in preparation. [5] Klassen, D. R. and Bell III, J. F. (2002) BAAS, 34, 865.

  11. Impact of Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask interpretation on cloud amount estimation

    NASA Astrophysics Data System (ADS)

    Kotarba, Andrzej Z.

    2015-09-01

    Cloud masks serve as a basis for estimates of cloud amount, which is an essential parameter for studying the Earth's radiation budget. The most commonly used cloud mask is a simple thematic classification, which includes qualitative information on the presence of clouds in the satellite's instantaneous field of view (IFOV). Cloud mask classes have to be "translated" into a quantitative measure, in order to be used for cloud amount calculations. The assignment of cloud fractions to cloud mask classes is a subjective process and increases uncertainty in cloud amount estimates. We evaluated this degree of uncertainty using the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask product. Together with the operational MODIS cloud mask interpretation, we investigated two extreme alternatives: "rigorous" (only "confident cloudy" IFOVs were 100% cloudy) and "tolerant" (only "confident clear" IFOVs were 0% cloudy). Results showed that the range of uncertainty was 14.3% in Europe and controlled by the frequency of small convective clouds. Comparison with surface-based observations suggests that the rigorous interpretation of the cloud mask is more accurate than that used operationally for MODIS level 3 product generation. The rigorous approach resulted in the smallest bias (-0.7%), the smallest root-mean-square error (4.6%), the small standard deviation (6%), and the strongest correlation (0.935). These results suggest that for climatological applications the rigorous scenario should be considered as a more accurate "best guess" over land.

  12. Automated Recognition of Oceanic Cloud Patterns and its Application to Remote Sensing of Meteorological Parameters

    NASA Astrophysics Data System (ADS)

    Garand, Louis Joseph Charles

    A scheme is presented for the automated classification of oceanic cloud patterns in twenty classes. A training set is defined by 2000 samples of size 128 x 128 km taken in February 1984 over the Western Atlantic. The method uses visible and infrared images from a geostationary satellite. Class discrimination is obtained from thirteen features representing height, albedo, shape and multi-layering characteristics. Features derived from the two-dimensional power spectrum of the visible images proved essential for the detection of directional patterns (streets, rolls) and open cells. A simple classification algorithm is developed based on the assumption of multivariate normal distributions of the features. From 1020 independent samples, the consensus among three expert nephanalysts is an overall accuracy of 79% with the machine answer at least second best 89% of the time. The cloud climatology in twenty classes for January and February 1984 are compared. The physical characteristics of the classes labeled by machine are investigated from collocation of 2130 cloud patterns with ship observations. It is shown that realistic estimates of the probability of precipitation can be inferred from the cloud patterns. For several meteorological parameters, multiple linear regressions involving satellite features are used to lower the variance within a class. For example, the satellite retrieved cloud base temperature is shown to be strongly related to the surface air temperature (Ta) and dew point (TD). Single retrievals of Ta and TD have rms errors less than 3.5 K for half of the classes whereas the seasonal maps over the entire domain show rms errors of 1.45 K and 1.70 K, respectively. Cloud pattern identification also leads to estimates of wind speed and sea-air temperature and humidity difference, with rms errors on seasonal retrievals of 0.92 m/s, 1.27 K and 1.36 g/kg, respectively. Resulting rms errors on the sensible and latent heat fluxes are 26 W/m('2) and 73 W/m('2), respectively. Thus, a promising method, based on the information provided by cloud patterns, is proposed for the remote sensing of meteorological parameters in cloudy atmospheres.

  13. Cloud classification using whole-sky imager data

    SciTech Connect

    Buch, K.A. Jr.; Sun, Chen-Hui

    1995-02-01

    Clouds are one of the most important moderators of the earth radiation budget and one of the least understood. The effect that clouds have on the reflection and absorption of solar and terrestrial radiation is strongly influenced by their shape, size, and composition. Physically accurate parameterization of clouds is necessary for any general circulation model (GCM) to yield meaningful results. The work presented here is part of a larger project that is aimed at producing realistic three-dimensional (3D) volume renderings of cloud scenes, thereby providing the important shape information for parameterizing GCMs. The specific goal of the current study is to develop an algorithm that automatically classifies (by cloud type) the clouds observed in the scene. This information will assist the volume rendering program in determining the shape of the cloud. Much work has been done on cloud classification using multispectral satellite images. Most of these references use some kind of texture measure to distinguish the different cloud types and some also use topological features (such as cloud/sky connectivity or total number of clouds). A wide variety of classification methods has been used, including neural networks, various types of clustering, and thresholding. The work presented here utilizes binary decision trees to distinguish the different cloud types based on cloud feature vectors.

  14. Cloud level winds from the Venus Express Monitoring Camera imaging

    NASA Astrophysics Data System (ADS)

    Khatuntsev, I. V.; Patsaeva, M. V.; Titov, D. V.; Ignatiev, N. I.; Turin, A. V.; Limaye, S. S.; Markiewicz, W. J.; Almeida, M.; Roatsch, Th.; Moissl, R.

    2013-09-01

    Six years of continuous monitoring of Venus by European Space Agencys Venus Express orbiter provides an opportunity to study dynamics of the atmosphere our neighbor planet. Venus Monitoring Camera (VMC) on-board the orbiter has acquired the longest and the most complete so far set of ultra violet images of Venus. These images enable a study the cloud level circulation by tracking motion of the cloud features. The highly elliptical polar orbit of Venus Express provides optimal conditions for observations of the Southern hemisphere at varying spatial resolution. Out of the 2300 orbits of Venus Express over which the images used in the study cover about 10 Venus years. Out of these, we tracked cloud features in images obtained in 127 orbits by a manual cloud tracking technique and by a digital correlation method in 576 orbits. Total number of wind vectors derived in this work is 45,600 for the manual tracking and 391,600 for the digital method. This allowed us to determine the mean circulation, its long-term and diurnal trends, orbit-to-orbit variations and periodicities. We also present the first results of tracking features in the VMC near-IR images. In low latitudes the mean zonal wind at cloud tops (67 2 km following: Rossow, W.B., Del Genio, A.T., Eichler, T. [1990]. J. Atmos. Sci. 47, 2053-2084) is about 90 m/s with a maximum of about 100 m/s at 40-50S. Poleward of 50S the average zonal wind speed decreases with latitude. The corresponding atmospheric rotation period at cloud tops has a maximum of about 5 days at equator, decreases to approximately 3 days in middle latitudes and stays almost constant poleward from 50S. The mean poleward meridional wind slowly increases from zero value at the equator to about 10 m/s at 50S and then decreases to zero at the pole. The error of an individual measurement is 7.5-30 m/s. Wind speeds of 70-80 m/s were derived from near-IR images at low latitudes. The VMC observations indicate a long term trend for the zonal wind speed at low latitudes to increase from 85 m/s in the beginning of the mission to 110 m/s by the middle of 2012. VMC UV observations also showed significant short term variations of the mean flow. The velocity difference between consecutive orbits in the region of mid-latitude jet could reach 30 m/s that likely indicates vacillation of the mean flow between jet-like regime and quasi-solid body rotation at mid-latitudes. Fourier analysis revealed periodicities in the zonal circulation at low latitudes. Within the equatorial region, up to 35S, the zonal wind show an oscillation with a period of 4.1-5 days (4.83 days on average) that is close to the super-rotation period at the equator. The wave amplitude is 4-17 m/s and decreases with latitude, a feature of the Kelvin wave. The VMC observations showed a clear diurnal signature. A minimum in the zonal speed was found close to the noon (11-14 h) and maxima in the morning (8-9 h) and in the evening (16-17 h). The meridional component peaks in the early afternoon (13-15 h) at around 50S latitude. The minimum of the meridional component is located at low latitudes in the morning (8-11 h). The horizontal divergence of the mean cloud motions associated with the diurnal pattern suggests upwelling motions in the morning at low latitudes and downwelling flow in the afternoon in the cold collar region.

  15. Radiometric cloud imaging with an uncooled microbolometer thermal infrared camera.

    PubMed

    Shaw, Joseph; Nugent, Paul; Pust, Nathan; Thurairajah, Brentha; Mizutani, Kohei

    2005-07-25

    An uncooled microbolometer-array thermal infrared camera has been incorporated into a remote sensing system for radiometric sky imaging. The radiometric calibration is validated and improved through direct comparison with spectrally integrated data from the Atmospheric Emitted Radiance Interferometer (AERI). With the improved calibration, the Infrared Cloud Imager (ICI) system routinely obtains sky images with radiometric uncertainty less than 0.5 W/(m(2 )sr) for extended deployments in challenging field environments. We demonstrate the infrared cloud imaging technique with still and time-lapse imagery of clear and cloudy skies, including stratus, cirrus, and wave clouds. PMID:19498585

  16. Restoration of cloud contaminated ocean color images using numerical simulation

    NASA Astrophysics Data System (ADS)

    Yang, Xuefei; Mao, Zhihua; Chen, Jianyu; Huang, Haiqing

    2015-10-01

    It is very hard to access cloud-free remote sensing data, especially for the ocean color images. A cloud removal approach from ocean color satellite images based on numerical modeling is introduced. The approach removes cloud-contaminated portions and then reconstructs the missing data utilizing model simulated values. The basic idea is to create the relationship between cloud-free patches and cloud-contaminated patches under the assumption that both of them are influenced by the same marine hydrodynamic conditions. Firstly, we find cloud-free GOCI (the Geostationary Ocean Color Imager) retrieved suspended sediment concentrations (SSC) in the East China Sea before and after the time of cloudy images, which are set as initial field and validation data for numerical model, respectively. Secondly, a sediment transport model based on COHERENS, a coupled hydrodynamic-ecological ocean model for regional and shelf seas, is configured. The comparison between simulated results and validation images show that the sediment transport model can be used to simulate actual sediment distribution and transport in the East China Sea. Then, the simulated SSCs corresponding to the cloudy portions are used to remove the cloud and replace the missing values. Finally, the accuracy assessments of the results are carried out by visual and statistical analysis. The experimental results demonstrate that the proposed method can effectively remove cloud from GOCI images and reconstruct the missing data, which is a new way to enhance the effectiveness and availability of ocean color data, and is of great practical significance.

  17. Data and image fusion for geometrical cloud characterization

    SciTech Connect

    Thorne, L.R.; Buch, K.A.; Sun, Chen-Hui; Diegert, C.

    1997-04-01

    Clouds have a strong influence on the Earth`s climate and therefore on climate change. An important step in improving the accuracy of models that predict global climate change, general circulation models, is improving the parameterization of clouds and cloud-radiation interactions. Improvements in the next generation models will likely include the effect of cloud geometry on the cloud-radiation parameterizations. We have developed and report here methods for characterizing the geometrical features and three-dimensional properties of clouds that could be of significant value in developing these new parameterizations. We developed and report here a means of generating and imaging synthetic clouds which we used to test our characterization algorithms; a method for using Taylor`s hypotheses to infer spatial averages from temporal averages of cloud properties; a computer method for automatically classifying cloud types in an image; and a method for producing numerical three-dimensional renderings of cloud fields based on the fusion of ground-based and satellite images together with meteorological data.

  18. Cloud morphology and motions from Pioneer Venus images

    NASA Technical Reports Server (NTRS)

    Rossow, W. B.; Del Genio, A. D.; Limaye, S. S.; Travis, L. D.; Stone, P. H.

    1980-01-01

    The horizontal and vertical cloud structures, atmospheric waves, and wind velocities at the cloud top level were determined by the Pioneer Venus photopolarimeter images in the UV from January through March 1979. The images indicate long-term evolution of cloud characteristics, the atmospheric dynamics, and rapid small changes in cloud morphology. The clouds show a globally coordinated oscillation relative to latitude circles; retrograde zonal winds of 100 m/s near the equator are determined from the tracking of small-scale cloud properties, but two hemispheres show important variations. The zonal wind velocity in the southern hemisphere is reduced toward the poles at a rate similar to solid body rotation; the midlatitude jet stream noted by Mariner 10 is not observed.

  19. Horizontal winds derived from the polar mesospheric cloud images as observed by the CIPS instrument on the AIM satellite

    NASA Astrophysics Data System (ADS)

    Rong, P. P.; Yue, J.; Russell, J. M.; Lumpe, J. D.; Gong, J.; Wu, D. L.; Randall, C. E.

    2015-06-01

    A cloud pattern matching technique is applied to polar mesospheric cloud (PMC) images taken by the Cloud Imaging and Particle Size instrument (CIPS) to infer the wind velocities in the mesopause region. CIPS measurements are analyzed to detect patterns that repeat from one orbit to the next but are displaced in location; the displacement provides a measure of the wind velocity. Pattern matching is achieved by resampling the CIPS data to longitude and latitude grids with the grid-box size forced at ~5 km in both directions. The correlated patterns are searched within a geographic region referred to as a "frame" of ~500 km in longitude 400 km in latitude. The histograms of the derived velocities indicate that easterly winds prevail, with a mean zonal wind of -20 to -15 m/s. Mean meridional winds are overall small, but in late summer the histogram indicated a poleward wind of ~20-30 m/s. The variability of CIPS cloud albedo on consecutive orbits is also examined at fixed geolocations. The statistical results suggest that ~86% of pairs underwent mean cloud albedo variation of < 50% on consecutive orbits, suggesting a moderate change. It is also found that the correlation of the cloud structures between two consecutive orbits at a fixed location is generally poor. These findings suggest that cloud patterns are subject to wind advection, but the cloud patches are more extended in size than the movement that occurs. Cloud voids are found to be more likely to remain at the same geolocations.

  20. Cloud Detection Method Based on Feature Extraction in Remote Sensing Images

    NASA Astrophysics Data System (ADS)

    Changhui, Y.; Yuan, Y.; Minjing, M.; Menglu, Z.

    2013-05-01

    In remote sensing images, the existence of the clouds has a great impact on the image quality and subsequent image processing, as the images covered with clouds contain little useful information. Therefore, the detection and recognition of clouds is one of the major problems in the application of remote sensing images. Present there are two categories of method to cloud detection. One is setting spectrum thresholds based on the characteristics of the clouds to distinguish them. However, the instability and uncertainty of the practical clouds makes this kind of method complexity and weak adaptability. The other method adopts the features in the images to identify the clouds. Since there will be significant overlaps in some features of the clouds and grounds, the detection result is highly dependent on the effectiveness of the features. This paper presented a cloud detection method based on feature extraction for remote sensing images. At first, find out effective features through training pattern, the features are selected from gray, frequency and texture domains. The different features in the three domains of the training samples are calculated. Through the result of statistical analysis of all the features, the useful features are picked up to form a feature set. In concrete, the set includes three feature vectors, respectively, the gray feature vector constituted of average gray, variance, first-order difference, entropy and histogram, the frequency feature vector constituted of DCT high frequency coefficient and wavelet high frequency coefficient, and the texture feature vector constituted of the hybrid entropy and difference of the gray-gradient co-occurrence matrix and the image fractal dimension. Secondly, a thumbnail will be obtained by down sampling the original image and its features of gray, frequency and texture are computed. Last but not least, the cloud region will be judged by the comparison between the actual feature values and the thresholds determined by the sample training process. Experimental results show that the clouds and ground objects can be separated efficiently, and our method can implement rapid clouds detection and cloudiness calculation.

  1. Cloud Cover Measurement from All-Sky Nighttime Images

    NASA Astrophysics Data System (ADS)

    Yin, Jia; Yao, Yongqiang; Liu, Liyong; Qian, Xuan; Wang, Hongshuai

    2015-04-01

    The site quality of astronomical observatory critically depends on cloud coverage, and the measurement of cloudiness is particularly important for site survey. A method to deal with all-sky images in no-moon nights is described. By identifying the positions of bright reference stars and making photometry for a set of all-sky images in clear nights, we can set up a reference image with median smoothing differential magnitude values. The standard image can be taken as the threshold for clear nights, and the detectivity of stars on other images can be utilize to reveal cloud coverage. Four types of all-sky images, clear night, icy lens, part of cloud, and full of cloud, are selected to check up the method. For the moonlight image, the formula of the CIE (Commission International de l'Eclairage ) standard general sky model are used to fit the luminance distribution of the image, then to estimate the cloud cover of the image from the difference between the fitting image and the real image.

  2. Female-pattern baldness (image)

    MedlinePLUS

    Female-pattern baldness is a pattern of hair loss (alopecia) caused by hormones, aging and genetics. Unlike male-pattern baldness, female-pattern baldness is an over-all thinning which maintains the normal ...

  3. Image transfer through cirrus clouds. II. Wave-front segmentation and imaging.

    PubMed

    Landesman, Barbara T; Matson, Charles L

    2002-12-20

    A hybrid technique to simulate the imaging of space-based objects through cirrus clouds is presented. The method makes use of standard Huygens-Fresnel propagation beyond the cloud boundary and a novel vector trace approach within the cloud. At the top of the cloud, the wave front is divided into an array of input gradient vectors, which are in turn transmitted through the cloud model by use of the Coherent Illumination Ray Trace and Imaging Software for Cirrus. At the bottom of the cloud, the output vector distribution is used to reconstruct a wave front that continues propagating to the ground receiver. Images of the object as seen through cirrus clouds with different optical depths are compared with a diffraction-limited image. Turbulence effects from the atmospheric propagation are not included. PMID:12510928

  4. Automatic cloud coverage assessment of Formosat-2 image

    NASA Astrophysics Data System (ADS)

    Hsu, Kuo-Hsien

    2011-11-01

    Formosat-2 satellite equips with the high-spatial-resolution (2m ground sampling distance) remote sensing instrument. It has been being operated on the daily-revisiting mission orbit by National Space organization (NSPO) of Taiwan since May 21 2004. NSPO has also serving as one of the ground receiving stations for daily processing the received Formosat- 2 images. The current cloud coverage assessment of Formosat-2 image for NSPO Image Processing System generally consists of two major steps. Firstly, an un-supervised K-means method is used for automatically estimating the cloud statistic of Formosat-2 image. Secondly, manual estimation of cloud coverage from Formosat-2 image is processed by manual examination. Apparently, a more accurate Automatic Cloud Coverage Assessment (ACCA) method certainly increases the efficiency of processing step 2 with a good prediction of cloud statistic. In this paper, mainly based on the research results from Chang et al, Irish, and Gotoh, we propose a modified Formosat-2 ACCA method which considered pre-processing and post-processing analysis. For pre-processing analysis, cloud statistic is determined by using un-supervised K-means classification, Sobel's method, Otsu's method, non-cloudy pixels reexamination, and cross-band filter method. Box-Counting fractal method is considered as a post-processing tool to double check the results of pre-processing analysis for increasing the efficiency of manual examination.

  5. A holistic image segmentation framework for cloud detection and extraction

    NASA Astrophysics Data System (ADS)

    Shen, Dan; Xu, Haotian; Blasch, Erik; Horvath, Gregory; Pham, Khanh; Zheng, Yufeng; Ling, Haibin; Chen, Genshe

    2013-05-01

    Atmospheric clouds are commonly encountered phenomena affecting visual tracking from air-borne or space-borne sensors. Generally clouds are difficult to detect and extract because they are complex in shape and interact with sunlight in a complex fashion. In this paper, we propose a clustering game theoretic image segmentation based approach to identify, extract, and patch clouds. In our framework, the first step is to decompose a given image containing clouds. The problem of image segmentation is considered as a "clustering game". Within this context, the notion of a cluster is equivalent to a classical equilibrium concept from game theory, as the game equilibrium reflects both the internal and external (e.g., two-player) cluster conditions. To obtain the evolutionary stable strategies, we explore three evolutionary dynamics: fictitious play, replicator dynamics, and infection and immunization dynamics (InImDyn). Secondly, we use the boundary and shape features to refine the cloud segments. This step can lower the false alarm rate. In the third step, we remove the detected clouds and patch the empty spots by performing background recovery. We demonstrate our cloud detection framework on a video clip provides supportive results.

  6. The Mars Imager for Cloud and Aerosol (MICA) instrument concept

    NASA Astrophysics Data System (ADS)

    Hipkin, V.; Drummond, J.; Hackett, J.; Besla, G.

    2004-05-01

    Cloud and dust play an important role in the Mars polar atmosphere. Of particular interest is the evolution of cap-edge dust storms observed during the Mars Global Surveyor mission, and the development of the polar hood and aphelion cloud band. This poster describes the Mars Imager for Cloud and Aerosol (MICA), a four-band visible camera designed to characterize Mars cloud and dust by imaging the limb at sunrise and sunset. MICA will be capable of producing profiles of Mars aerosol optical properties from 0-75km altitude with a vertical resolution better than 600m. The MICA design uses multiple bands and a new occulting disk technique to provide enhanced dust characterization capabilities. The full dynamic range of the camera is optimized for atmospheric scattered light. A pinhole in the occulting disk attenuates direct sunlight, reducing its intensity to levels produced by the atmospheric scattering. The resulting composite image contains both a detailed image of the sun and a sensitive wide-angle image of the distribution of thin cloud and aerosol layers. Absolute calibration is possible through viewing the sun at high angles above the atmosphere. The calibrated solar image produces particle extinction measurements directly, while the wide-angle part of the image can be used to fit the scattering phase function in the case of horizontally homoge-neous layers. These measurements will provide new constraints on Mars aerosol particle size distribution and optical properties. The addition of a flip mirror gives MICA the capability also to observe the surface. MICA was conceived as part of the MARVEL Scout proposal. It is intended that it will follow on from Mars Express and MRO cloud and aerosol vertical profile mapping, providing new information, higher vertical resolution and adding to the Mars cloud and dust climatology.

  7. Climatic shift in patterns of shallow clouds over the Amazon

    NASA Astrophysics Data System (ADS)

    Chagnon, F. J. F.; Bras, R. L.; Wang, J.

    2004-12-01

    The Amazon rain forest has experienced dramatic changes in the past 50 years due to active deforestation. As of 2001, 15% of the 4,000,000 km2 Brazilian Amazon has been deforested [Instituto Nacional de Pesquisas Espaciais (INPE), 2003]; each year, agricultural exploitation claims an estimated 13,000 km2 of tropical forest [Achard et al., 2002]. In this paper we investigate the climatic effects caused by the observed change of the physical characteristics of the land surface (i.e., increased surface albedo, decreased root-zone depth, decreased surface roughness and decreased leaf-area index). More precisely, we examine the spatial correspondence of shallow cumulus clouds with deforestation. Through the creation of an 8-year record of thrice daily shallow cumulus cloud cover at 1 km resolution from multi-spectral satellite imagery, we quantitatively show the existence of a significant climatic shift in shallow cloudiness patterns associated with deforestation. This shift manifests itself as an enhancement of shallow cumuli over deforested patches, and has potentially important climatic, hydrologic and ecological implications.

  8. Space Shuttle Video Images: An Example of Warm Cloud Lightning

    NASA Technical Reports Server (NTRS)

    Vaughan, Otha H., Jr.; Boeck, William L.

    1998-01-01

    Warm cloud lightning has been reported in several tropical locations. We have been using the intensified monochrome TV cameras at night during a number of shuttle flights to observe large active thunderstorms and their associated lightning. During a nighttime orbital pass of the STS-70 mission on 17 July 1995 at 07:57:42 GMT, the controllers obtained video imagery of a small cloud that was producing lightning. Data from a GOES infrared image establishes that the cloud top had a temperature of about 271 degrees Kelvin ( -2 degrees Celsius). Since this cloud was electrified to the extent that a lightning discharge did occur, it may be another case of lightning in a cloud that presents little if any evidence of frozen or melting precipitation.

  9. An enhanced neighborhood similar pixel interpolator approach for removing thick clouds in landsat images

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thick cloud contaminations in Landsat images limit their regular usage for land applications. A few methods have been developed to remove thick clouds using additional cloud-free images. Unfortunately, the cloud-free composition image produced by existing methods commonly lacks from the desired spat...

  10. Skin lesions image analysis utilizing smartphones and cloud platforms.

    PubMed

    Doukas, Charalampos; Stagkopoulos, Paris; Maglogiannis, Ilias

    2015-01-01

    This chapter presents the state of the art on mobile teledermoscopy applications, utilizing smartphones able to store digital images of skin areas depicting regions of interest (lesions) and perform self-assessment or communicate the captured images with expert physicians. Mobile teledermoscopy systems consist of a mobile application that can acquire and identify moles in skin images and classify them according their severity and Cloud infrastructure exploiting computational and storage resources. The chapter presents some indicative mobile applications for skin lesions assessment and describes a proposed system developed by our team that can perform skin lesion evaluation both on the phone and on the Cloud, depending on the network availability. PMID:25626556

  11. Jovian cloud structure from 5-mu M images

    NASA Astrophysics Data System (ADS)

    Ortiz, J. L.; Moreno, F.; Molina, A.; Roos-Serote, M.; Orton, G. S.

    1999-09-01

    Most radiative transfer studies place the cloud clearings responsible for the 5-mu m bright areas at pressure levels greater than 1.5 bar whereas the low-albedo clouds are placed at lower pressure levels, in the so-called ammonia cloud. If this picture is correct, and assuming that the strong vertical shear of the zonal wind detected by the Galileo Entry Probe exists at all latitudes in Jupiter, the bright areas at 5 mu m should drift faster than the dark clouds, which is not observed. At the Galileo Probe Entry latitude this can be explained by a wave, but this is not a likely explanation for all regions where the anticorrelation between 5-mu m brightness and red-nIR reflectivity is observed. Therefore, either the vertical zonal wind shears are not global or cloud clearings and dark clouds are located at the same pressure level. We have developed a multiple scattering radiative transfer code to model the limb-darkening at several jovian features derived from IRTF 4.8-mu m images, in order to retrieve information on the cloud levels. The limb darkening coefficients range from 1.4 at hot spots to 0.58 at the Equatorial Region. We also find that reflected light is dominant over thermal emission in the Equatorial Region, as already pointed out by other investigators. Preliminary results from our code tend to favor the idea that the ammonia cloud is a very high-albedo cloud with little influence on the contrast seen in the red and nIR and that a deeper cloud at P >1.5 bar can be responsible for the cloud clearings and for the low-albedo features simultaneously. This research was supported by the Comision Interministerial de Ciencia y Tecnologia under contract ESP96-0623.

  12. Global patterns of cloud optical thickness variation with temperature and the implications for climate change

    SciTech Connect

    Tselioudis, G.

    1992-01-01

    This thesis presents a correlative analysis of cloud optical thickness and cloud temperature in large space and time scales. The analysis is designed to document and explain the patterns of cloud optical thickness variation with temperature, and to produce an understanding of cloud optical property feedbacks on climate change. The results of the global correlations between cloud optical thickness and temperature are presented. The analysis focuses on low clouds to limit variations in cloud vertical extent, particle size and water phase. Coherent patterns of change are observed on several time and space scales. On the planetary and the seasonal scales, clouds in the colder latitudes and seasons are optically thicker than clouds in the warmer latitudes and seasons. The seasonal, latitudinal, and day-to-day variations of this relation show that in cold continental clouds optical thickness increases with temperature consistent with the temperature variation of the adiabatic cloud water content, but in warm continental and in most maritime clouds optical thickness decreases with temperature. Case studies are presented to identify the cloud parameters responsible for the optical thickness changes and to resolve the atmospheric processes that produce those changes. The temperature variation of low cloud optical thickness primarily reflect changes in the liquid water content of the clouds, and changes in cloud particle size and vertical extent play a secondary role. It is proposed that an increase in the efficiency of formation of warm rain at higher temperatures relative to condensation, raises the probability of occurrence of optically thin clouds at warmer temperatures and produces the observed negative optical thickness slopes. A two dimensional radiative convective model is used to estimate the magnitude and sign of the feedback that the observed cloud optical thickness changes would produce in a climate warming scenario.

  13. Jupiter's cloud distribution between the Voyager 1 and 2 encounters - Results from 5-micrometer imaging

    NASA Technical Reports Server (NTRS)

    Terrile, R. J.; Capps, R. W.; Becklin, E. E.; Cruikshank, D. P.

    1979-01-01

    As part of a continuing effort of ground-based support for Voyager target selection, infrared images in the 5-micrometer wavelength region were acquired in preparation for the Voyager 2 flyby of Jupiter. Observations were made during May 1979 from the Palomar 5-meter telescope and the new 3-meter NASA Infrared Telescope Facility at Mauna Kea and are compared to previous observations. Variations seen in the 5-micrometer flux distribution suggest global patterns of clouding over of some Jovian belts and clearing of others. These data were used to predict the Jovian cloud distribution at the time of the Voyager 2 encounter in order to target the imaging and infrared experiments to areas free of high obscuring clouds.

  14. Jupiter's Cloud Distribution Between the Voyager 1 and 2 Encounters: Results from 5-Micrometer Imaging.

    PubMed

    Terrile, R J; Capps, R W; Becklin, E E; Cruikshank, D P

    1979-11-23

    As part of a continuing effort of ground-based support for Voyager target selection, infrared images in the 5-micrometer wavelength region were acquired in preparation for the Voyager 2 flyby of Jupiter. Observations were made during May 1979 from the Palomar 5-meter telescope and the new 3-meter NASA Infrared Telescope Facility at Mauna Kea and are compared to previous observations. Variations seen in the 5-micrometer flux distribution suggest global patterns of clouding over of some Jovian belts and clearing ofothers. These data were used to predict the Jovian cloud distribution at the time of the Voyager 2 encounter in order to target the imaging and infrared experiments to areas free of high obscuring clouds. PMID:17733922

  15. High-resolution Images of Diffuse Neutral Clouds in the Milky Way. I. Observations, Imaging, and Basic Cloud Properties

    NASA Astrophysics Data System (ADS)

    Pidopryhora, Y.; Lockman, Felix J.; Dickey, J. M.; Rupen, M. P.

    2015-08-01

    A set of diffuse interstellar clouds in the inner Galaxy within a few hundred parsecs of the Galactic plane has been observed at an angular resolution of ?1&farcm0 combining data from the NRAO Green Bank Telescope and the Very Large Array. At the distance of the clouds, the linear resolution ranges from 1.9 to 2.8 pc. These clouds have been selected to be somewhat outside of the Galactic plane, and thus are not confused with unrelated emission, but in other respects they are a Galactic population. They are located near the tangent points in the inner Galaxy, and thus at a quantifiable distance: 2.3?slant R?slant 6.0 kpc from the Galactic Center and -1000?slant z?slant +610 pc from the Galactic plane. These are the first images of the diffuse neutral H i clouds that may constitute a considerable fraction of the interstellar medium (ISM). Peak H i column densities lie in the range NH i = 0.8-2.9 1020 cm-2. Cloud diameters vary between about 10 and 100 pc, and their H i mass spans the range from less than a hundred to a few thousands M?. The clouds show no morphological consistency of any kind, except that their shapes are highly irregular. One cloud may lie within the hot wind from the nucleus of the Galaxy, and some clouds show evidence of two distinct thermal phases as would be expected from equilibrium models of the ISM.

  16. Images from galileo of the venus cloud deck.

    PubMed

    Belton, M J; Gierasch, P J; Smith, M D; Helfenstein, P; Schinder, P J; Pollack, J B; Rages, K A; Ingersoll, A P; Klaasen, K P; Veverka, J; Anger, C D; Carr, M H; Chapman, C R; Davies, M E; Fanale, F P; Greeley, R; Greenberg, R; Head, J W; Morrison, D; Neukum, G; Pilcher, C B

    1991-09-27

    Images of Venus taken at 418 (violet) and 986 [near-infrared (NIR)] nanometers show that the morphology and motions of large-scale features change with depth in the cloud deck. Poleward meridional velocities, seen in both spectral regions, are much reduced in the NIR In the south polar region the markings in the two wavelength bands are strongly anticorrelated. The images follow the changing state of the upper cloud layer downwind of the subsolar point, and the zonal flow field shows a longitudinal periodicity that may be coupled to the formation of large-scale planetary waves. No optical lightning was detected. PMID:17784096

  17. Images from Galileo of the Venus cloud deck

    USGS Publications Warehouse

    Belton, M.J.S.; Gierasch, P.J.; Smith, M.D.; Helfenstein, P.; Schinder, P.J.; Pollack, James B.; Rages, K.A.; Ingersoll, A.P.; Klaasen, K.P.; Veverka, J.; Anger, C.D.; Carr, M.H.; Chapman, C.R.; Davies, M.E.; Fanale, F.P.; Greeley, R.; Greenberg, R.; Head, J. W., III; Morrison, D.; Neukum, G.; Pilcher, C.B.

    1991-01-01

    Images of Venus taken at 418 (violet) and 986 [near-infrared (NIR)] nanometers show that the morphology and motions of large-scale features change with depth in the cloud deck. Poleward meridional velocities, seen in both spectral regions, are much reduced in the NIR. In the south polar region the markings in the two wavelength bands are strongly anticorrelated. The images follow the changing state of the upper cloud layer downwind of the subsolar point, and the zonal flow field shows a longitudinal periodicity that may be coupled to the formation of large-scale planetary waves. No optical lightning was detected.

  18. Secure public cloud platform for medical images sharing.

    PubMed

    Pan, Wei; Coatrieux, Gouenou; Bouslimi, Dalel; Prigent, Nicolas

    2015-01-01

    Cloud computing promises medical imaging services offering large storage and computing capabilities for limited costs. In this data outsourcing framework, one of the greatest issues to deal with is data security. To do so, we propose to secure a public cloud platform devoted to medical image sharing by defining and deploying a security policy so as to control various security mechanisms. This policy stands on a risk assessment we conducted so as to identify security objectives with a special interest for digital content protection. These objectives are addressed by means of different security mechanisms like access and usage control policy, partial-encryption and watermarking. PMID:25991144

  19. Images from Galileo of the Venus cloud deck

    NASA Technical Reports Server (NTRS)

    Belton, Michael J. S.; Gierasch, Peter J.; Smith, Michael D.; Helfenstein, Paul; Schinder, Paul J.; Pollack, James B.; Rages, Kathy A.; Morrison, David; Klaasen, Kenneth P.; Pilcher, Carl B.

    1991-01-01

    Images of Venus taken at 418 and 986 nm show that the morphology and motions of large-scale features change with depth in the cloud deck. Poleward meridional velocities, seen in both spectral regions, are much reduced in the NIR. In the south polar region the markings in the two wavelength bands are strongly anticorrelated. The images follow the changing state of the upper cloud layer downwind of the subsolar point, and the zonal flowfield shows a longitudinal periodicity that may be coupled to the formation of large-scale planetary waves. No optical lightning was detected.

  20. Cloud screening Coastal Zone Color Scanner images using channel 5

    NASA Technical Reports Server (NTRS)

    Eckstein, B. A.; Simpson, J. J.

    1991-01-01

    Clouds are removed from Coastal Zone Color Scanner (CZCS) data using channel 5. Instrumentation problems require pre-processing of channel 5 before an intelligent cloud-screening algorithm can be used. For example, at intervals of about 16 lines, the sensor records anomalously low radiances. Moreover, the calibration equation yields negative radiances when the sensor records zero counts, and pixels corrupted by electronic overshoot must also be excluded. The remaining pixels may then be used in conjunction with the procedure of Simpson and Humphrey to determine the CZCS cloud mask. These results plus in situ observations of phytoplankton pigment concentration show that pre-processing and proper cloud-screening of CZCS data are necessary for accurate satellite-derived pigment concentrations. This is especially true in the coastal margins, where pigment content is high and image distortion associated with electronic overshoot is also present. The pre-processing algorithm is critical to obtaining accurate global estimates of pigment from spacecraft data.

  1. Auotomatic Classification of Point Clouds Extracted from Ultracam Stereo Images

    NASA Astrophysics Data System (ADS)

    Modiri, M.; Masumi, M.; Eftekhari, A.

    2015-12-01

    Automatic extraction of building roofs, street and vegetation are a prerequisite for many GIS (Geographic Information System) applications, such as urban planning and 3D building reconstruction. Nowadays with advances in image processing and image matching technique by using feature base and template base image matching technique together dense point clouds are available. Point clouds classification is an important step in automatic features extraction. Therefore, in this study, the classification of point clouds based on features color and shape are implemented. We use two images by proper overlap getting by Ultracam-x camera in this study. The images are from Yasouj in IRAN. It is semi-urban area by building with different height. Our goal is classification buildings and vegetation in these points. In this article, an algorithm is developed based on the color characteristics of the point's cloud, using an appropriate DEM (Digital Elevation Model) and points clustering method. So that, firstly, trees and high vegetation are classified by using the point's color characteristics and vegetation index. Then, bare earth DEM is used to separate ground and non-ground points. Non-ground points are then divided into clusters based on height and local neighborhood. One or more clusters are initialized based on the maximum height of the points and then each cluster is extended by applying height and neighborhood constraints. Finally, planar roof segments are extracted from each cluster of points following a region-growing technique.

  2. South polar clouds on Titan imaged with adaptive optics on the Gemini and Keck telescopes

    NASA Astrophysics Data System (ADS)

    Roe, H. G.; de Pater, I.; Macintosh, B. A.; McKay, C. P.

    2002-09-01

    We report high spatial resolution narrowband imaging of Titan taken in December 2001 with adaptive optics on the Gemini North 8-meter and W.M. Keck II 10-meter telescopes. The narrowband filters were chosen to selectively probe Titan's surface, troposphere, and stratosphere. The data we present have been processed minimally using only standard near-infrared reduction techniques (sky subtraction, flat-fielding, and bad-pixel masking). Images in the tropospheric-probing filters show a general brightening south of ~50° S as well as discrete cloud features at far southern latitudes varying on the time scales of hours to days. In particular, over the period 18-21 December 2001 UT we observed the evolution of several features, including three discrete southern features (61° S, 76° S, and 85° S) that vary in intensity over just 3 hours on 21 December 2001 UT. In our tropospheric probing filter the flux from the discrete cloud features represents 0.1-1.% of Titan's total flux and the derived area for each cloud is in the range of 104}-10{5 km2, referenced to Titan's surface, making these cloud features apparently similar to those reported by Griffith (2000). Although Titan's global weather pattern almost certainly evolves on the timescale of years, our observations strongly suggest that the cloud features reported by Griffith et al.\\ (1998) and (2000) were in the southern polar region. We expect the current weather pattern to persist long enough that the Cassini mission should focus its initial Titan cloud observation plans on the southern polar region; due to the changing seasons on Titan, Cassini should look for clouds in the northern polar region later in its nominal mission. HGR was funded by a NASA Ames Research Center GSRP fellowship.

  3. Image Recognition Based on Biometric Pattern Recognition

    NASA Astrophysics Data System (ADS)

    Sun, Shuliang; Chen, Zhong; Liu, Chenglian; Guo, Yongning; Lin, Xueyun

    2011-09-01

    A new method, biomimetric pattern recognition, is mentioned to recognize images. At first, the image is pretreatment and feature extraction, then a high vector is got. A biomimetric pattern recognition model is designed. The judgment function is used to discriminate the classification of the samples. It is showed that the method is effective for little samples by experiment. It would be useful in many fields in future.

  4. Cloud Detection with the Earth Polychromatic Imaging Camera (EPIC)

    NASA Technical Reports Server (NTRS)

    Meyer, Kerry; Marshak, Alexander; Lyapustin, Alexei; Torres, Omar; Wang, Yugie

    2011-01-01

    The Earth Polychromatic Imaging Camera (EPIC) on board the Deep Space Climate Observatory (DSCOVR) would provide a unique opportunity for Earth and atmospheric research due not only to its Lagrange point sun-synchronous orbit, but also to the potential for synergistic use of spectral channels in both the UV and visible spectrum. As a prerequisite for most applications, the ability to detect the presence of clouds in a given field of view, known as cloud masking, is of utmost importance. It serves to determine both the potential for cloud contamination in clear-sky applications (e.g., land surface products and aerosol retrievals) and clear-sky contamination in cloud applications (e.g., cloud height and property retrievals). To this end, a preliminary cloud mask algorithm has been developed for EPIC that applies thresholds to reflected UV and visible radiances, as well as to reflected radiance ratios. This algorithm has been tested with simulated EPIC radiances over both land and ocean scenes, with satisfactory results. These test results, as well as algorithm sensitivity to potential instrument uncertainties, will be presented.

  5. Cloud detection with the Earth Polychromatic Imaging Camera (EPIC)

    NASA Astrophysics Data System (ADS)

    Meyer, K.; Marshak, A.; Lyapustin, A.; Torres, O.; Wang, Y.

    2011-12-01

    The Earth Polychromatic Imaging Camera (EPIC) on board the Deep Space Climate Observatory (DSCOVR) would provide a unique opportunity for Earth and atmospheric research due not only to its Lagrange point sun-synchronous orbit, but also to the potential for synergistic use of spectral channels in both the UV and visible spectrum. As a prerequisite for most applications, the ability to detect the presence of clouds in a given field of view, known as cloud masking, is of utmost importance. It serves to determine both the potential for cloud contamination in clear-sky applications (e.g., land surface products and aerosol retrievals) and clear-sky contamination in cloud applications (e.g., cloud height and property retrievals). To this end, a preliminary cloud mask algorithm has been developed for EPIC that applies thresholds to reflected UV and visible radiances, as well as to reflected radiance ratios. This algorithm has been tested with simulated EPIC radiances over both land and ocean scenes, with satisfactory results. These test results, as well as algorithm sensitivity to potential instrument uncertainties, will be presented.

  6. Cloud Image Data Center for Healthcare Network in Taiwan.

    PubMed

    Weng, Shao-Jen; Lai, Lai-Shiun; Gotcher, Donald; Wu, Hsin-Hung; Xu, Yeong-Yuh; Yang, Ching-Wen

    2016-04-01

    This paper investigates how a healthcare network in Taiwan uses a practical cloud image data center (CIDC) to communicate with its constituent hospital branches. A case study approach was used. The study was carried out in the central region of Taiwan, with four hospitals belonging to the Veterans Hospital healthcare network. The CIDC provides synchronous and asynchronous consultation among these branches. It provides storage, platforms, and services on demand to the hospitals. Any branch-client can pull up the patient's medical images from any hospital off this cloud. Patients can be examined at the branches, and the images and reports can be further evaluated by physicians in the main Taichung Veterans General Hospital (TVGH) to enhance the usage and efficiency of equipment in the various branches, thereby shortening the waiting time of patients. The performance of the CIDC over 5 years shows: (1) the total number of cross-hospital images accessed with CDC in the branches was 132,712; and (2) TVGH assisted the branches in keying in image reports using the CIDC 4,424 times; and (3) Implementation of the system has improved management, efficiency, speed and quality of care. Therefore, the results lead to the recommendation of continuing and expanding the cloud computing architecture to improve information sharing among branches in the healthcare network. PMID:26846750

  7. A secure online image trading system for untrusted cloud environments.

    PubMed

    Munadi, Khairul; Arnia, Fitri; Syaryadhi, Mohd; Fujiyoshi, Masaaki; Kiya, Hitoshi

    2015-01-01

    In conventional image trading systems, images are usually stored unprotected on a server, rendering them vulnerable to untrusted server providers and malicious intruders. This paper proposes a conceptual image trading framework that enables secure storage and retrieval over Internet services. The process involves three parties: an image publisher, a server provider, and an image buyer. The aim is to facilitate secure storage and retrieval of original images for commercial transactions, while preventing untrusted server providers and unauthorized users from gaining access to true contents. The framework exploits the Discrete Cosine Transform (DCT) coefficients and the moment invariants of images. Original images are visually protected in the DCT domain, and stored on a repository server. Small representation of the original images, called thumbnails, are generated and made publicly accessible for browsing. When a buyer is interested in a thumbnail, he/she sends a query to retrieve the visually protected image. The thumbnails and protected images are matched using the DC component of the DCT coefficients and the moment invariant feature. After the matching process, the server returns the corresponding protected image to the buyer. However, the image remains visually protected unless a key is granted. Our target application is the online market, where publishers sell their stock images over the Internet using public cloud servers. PMID:26090324

  8. The algorithm to generate color point-cloud with the registration between panoramic image and laser point-cloud

    NASA Astrophysics Data System (ADS)

    Zeng, Fanyang; Zhong, Ruofei

    2014-03-01

    Laser point cloud contains only intensity information and it is necessary for visual interpretation to obtain color information from other sensor. Cameras can provide texture, color, and other information of the corresponding object. Points with color information of corresponding pixels in digital images can be used to generate color point-cloud and is conducive to the visualization, classification and modeling of point-cloud. Different types of digital cameras are used in different Mobile Measurement Systems (MMS).the principles and processes for generating color point-cloud in different systems are not the same. The most prominent feature of the panoramic images is the field of 360 degrees view angle in the horizontal direction, to obtain the image information around the camera as much as possible. In this paper, we introduce a method to generate color point-cloud with panoramic image and laser point-cloud, and deduce the equation of the correspondence between points in panoramic images and laser point-clouds. The fusion of panoramic image and laser point-cloud is according to the collinear principle of three points (the center of the omnidirectional multi-camera system, the image point on the sphere, the object point). The experimental results show that the proposed algorithm and formulae in this paper are correct.

  9. Forbidden coronal iron line images of Puppis A - Cloud evaporation or shocked cloud?

    NASA Astrophysics Data System (ADS)

    Teske, Richard G.; Petre, Robert

    1987-03-01

    Calibrated CCD images of the eastern X-ray knot in Puppis A, made in the forbidden red and green coronal Fe lines, are discussed. They show the high-temperature gas to have a rich morphology, with the scale of some features approaching the 2.6 arcsec resolution of the data. The pictures have been compared with an Einstein HRI soft X-ray image; there is close correspondence in the position and size of structures seen in the optical forbidden lines and in the X-rays. Located near the shock front a cloud of about 0.4 pc x 0.9 pc dimension shines brilliantly in the 5303 A line. To test the hypothesis that the cloud might be evaporating into the remnant interior, the 5303 A and 6374 A intensity distributions expected for a steady state, one-fluid evaporatig model have been computed.

  10. Leveraging the Cloud for Robust and Efficient Lunar Image Processing

    NASA Technical Reports Server (NTRS)

    Chang, George; Malhotra, Shan; Wolgast, Paul

    2011-01-01

    The Lunar Mapping and Modeling Project (LMMP) is tasked to aggregate lunar data, from the Apollo era to the latest instruments on the LRO spacecraft, into a central repository accessible by scientists and the general public. A critical function of this task is to provide users with the best solution for browsing the vast amounts of imagery available. The image files LMMP manages range from a few gigabytes to hundreds of gigabytes in size with new data arriving every day. Despite this ever-increasing amount of data, LMMP must make the data readily available in a timely manner for users to view and analyze. This is accomplished by tiling large images into smaller images using Hadoop, a distributed computing software platform implementation of the MapReduce framework, running on a small cluster of machines locally. Additionally, the software is implemented to use Amazon's Elastic Compute Cloud (EC2) facility. We also developed a hybrid solution to serve images to users by leveraging cloud storage using Amazon's Simple Storage Service (S3) for public data while keeping private information on our own data servers. By using Cloud Computing, we improve upon our local solution by reducing the need to manage our own hardware and computing infrastructure, thereby reducing costs. Further, by using a hybrid of local and cloud storage, we are able to provide data to our users more efficiently and securely. 12 This paper examines the use of a distributed approach with Hadoop to tile images, an approach that provides significant improvements in image processing time, from hours to minutes. This paper describes the constraints imposed on the solution and the resulting techniques developed for the hybrid solution of a customized Hadoop infrastructure over local and cloud resources in managing this ever-growing data set. It examines the performance trade-offs of using the more plentiful resources of the cloud, such as those provided by S3, against the bandwidth limitations such use encounters with remote resources. As part of this discussion this paper will outline some of the technologies employed, the reasons for their selection, the resulting performance metrics and the direction the project is headed based upon the demonstrated capabilities thus far.

  11. The pericardial effusion pattern on phase images

    SciTech Connect

    Pavel, C.M.; Kahn, J.; Rich, S.; Gonzalez, P.; Turner, S.; Pavel, D.G.

    1984-02-01

    The effect of pericardial effusion on phase images of gated studies was investigated. Twenty-six patients with suspected or known pericardial effusion were correlated with echocardiography and/or clinical and other laboratory data to ascertain the presence and size of effusion. The phase image pattern and parameters were compared to the results previously obtained in seven normal patients, and in 26 patients with documented regional wall motion abnormalities but no evidence of pericardial effusion. The phase pattern was graded into five categories: typical (IV) (wide histogram, well defined concentric convex pattern, progressive delay toward the inferolateral area, identifiable also over the right ventricle); less pronounced (III); atypical (II); ill defined changes (I); and normal (0). Results: Group L (large pericardial effusion): four of six had pattern (IV) and the left ventricular histogram showed abnormal parameters. These patients had large free effusions in the pericardial sac and none had regional wall motion abnormalities. Two of six had pattern (III) and (II) but also had ancillary pericardial pathology and/or decreased ejection fraction. Group M (moderate pericardial effusion), S (small pericardial effusion), and A (absent pericardial effusion, but not normal) had variable phase images and numeric parameters. After therapeutic drainage of pericardial fluid two patients changed pattern from IV and III to 0 and a third from III to I. Category IV pattern is 100% specific for pericardial effusion; the combination of category IV or III is 87.5% specific and 61% sensitive for large and moderate pericardial effusion.

  12. Feeding People's Curiosity: Leveraging the Cloud for Automatic Dissemination of Mars Images

    NASA Technical Reports Server (NTRS)

    Knight, David; Powell, Mark

    2013-01-01

    Smartphones and tablets have made wireless computing ubiquitous, and users expect instant, on-demand access to information. The Mars Science Laboratory (MSL) operations software suite, MSL InterfaCE (MSLICE), employs a different back-end image processing architecture compared to that of the Mars Exploration Rovers (MER) in order to better satisfy modern consumer-driven usage patterns and to offer greater server-side flexibility. Cloud services are a centerpiece of the server-side architecture that allows new image data to be delivered automatically to both scientists using MSLICE and the general public through the MSL website (http://mars.jpl.nasa.gov/msl/).

  13. Influence of atmospheric circulation patterns on local cloud and solar variability in Bergen, Norway

    NASA Astrophysics Data System (ADS)

    Parding, Kajsa; Olseth, Jan Asle; Liepert, Beate G.; Dagestad, Knut-Frode

    2015-06-01

    In a previous paper, we have shown that long-term cloud and solar observations (1965-2013) in Bergen, Norway (60.39N, 5.33E) are compatible with a largely cloud dominated radiative climate. Here, we explicitly address the relationship between the large scale circulation over Europe and local conditions in Bergen, identifying specific circulation shifts that have contributed to the observed cloud and solar variations. As a measure of synoptic weather patterns, we use the Grosswetterlagen (GWL), a daily classification of European weather for 1881-2013. Empirical models of cloud cover, cloud base, relative sunshine duration, and normalised global irradiance are constructed based on the GWL frequencies, extending the observational time series by more than 70 years. The GWL models successfully reproduce the observed increase in cloud cover and decrease in solar irradiance during the 1970s and 1980s. This cloud-induced dimming is traced to an increasing frequency of cyclonic and decreasing frequency of anticyclonic weather patterns over northern Europe. The changing circulation patterns in winter can be understood as a shift from the negative to the positive phase of the North Atlantic and Arctic Oscillation. A recent period of increasing solar irradiance is observed but not reproduce by the GWL models, suggesting this brightening is associated with factors other than large scale atmospheric circulation, possibly decreasing aerosol loads and local cloud shifts.

  14. Voyager imaging of Triton's clouds and hazes

    NASA Technical Reports Server (NTRS)

    Rages, Kathy; Pollack, James B.

    1992-01-01

    Results are presented from a detailed analysis of Voyager images of Triton obtained at the highest solar phase angles; these have been fit to Mie scattering models in order to obtain the mean particle sizes, number densities, and the vertical extent of the two different scattering components of the Triton atmosphere. The 0.001-0.01 optical depths of about 0.17 micron particles are vertically distributed with scale heights of about 10 km throughout Triton. A number of properties of the haze particles in question suggest that they are composed of photochemically produced gases which have condensed in the cold lower atmosphere of Triton.

  15. Multiscale image enhancement of chromosome banding patterns

    NASA Astrophysics Data System (ADS)

    Wu, Qiang; Castleman, Kenneth R.

    1996-10-01

    Visual examination of chromosome banding patterns is an important means of chromosome analysis. Cytogeneticists compare their patient's chromosome image against the prototype normal/abnormal human chromosome banding patterns. Automated chromosome analysis instruments facilitate this by digitally enhancing the chromosome images. Currently available systems employing traditional highpass/bandpass filtering and/or histogram equalization are approximately equivalent to photomicroscopy in their ability to support the detection of band pattern alterations. Improvements in chromosome image display quality, particularly in the detail of the banding pattern, would significantly increase the cost-effectiveness of these systems. In this paper we present our work on the use of multiscale transform and derivative filtering for image enhancement of chromosome banding patterns. A steerable pyramid representation of the chromosome image is generated by a multiscale transform. The derivative filters are designed to detect the bands of a chromosome, and the steerable pyramid transform is chosen based on its desirable properties of shift and rotation invariance. By processing the transform coefficients that correspond to the bands of the chromosome in the pyramid representation, contrast enhancement of the chromosome bands can be achieved with designed flexibility in scale, orientation and location. Compared with existing chromosome image enhancement techniques, this new approach offers the advantage of selective chromosome banding pattern enhancement that allows designated detail analysis. Experimental results indicate improved enhancement capabilities and promise more effective visual aid to comparison of chromosomes to the prototypes and to each other. This will increase the ability of automated chromosome analysis instruments to assist the evaluation of chromosome abnormalities in clinical samples.

  16. Speckle Patterns in Coherence Domain Biomedical Imaging

    NASA Astrophysics Data System (ADS)

    Yu, Ping

    2006-03-01

    We have shown previously that coherence domain biomedical imaging can be used for optically sectioning small tumors such as rat osteogenic sarcoma (bone tumors). Speckle patterns of such small tumors provided quantitative measures of the health, necrotic, and poisoned tissues. However, the origins of these speckle patterns are not clear. Although the nuclei, mitochondria and other organelles inside cells are responsible for the speckle under the illumination of low coherence light source, these patterns at the imaging plane are related to the photon pathways both inside and outside the tissue. We report systematic experiments and simulation of the speckle patterns from coherence domain imaging of small tumors. The image frames are acquired at different depths inside the tumor tissue and analyzed by using a turbid medium model. The results reveal that the speckle patterns are dominated by the scattering properties of the tissue, which is characterized by the mean free path of the photons, and the collection geometry of the backscattered light photons. This work was supported by a University of Missouri Research Board grant URB-04-072 and NIH grant P50-CA-103130.

  17. Research on earthquake prediction from infrared cloud images

    NASA Astrophysics Data System (ADS)

    Fan, Jing; Chen, Zhong; Yan, Liang; Gong, Jing; Wang, Dong

    2015-12-01

    In recent years, the occurrence of large earthquakes is frequent all over the word. In the face of the inevitable natural disasters, the prediction of the earthquake is particularly important to avoid more loss of life and property. Many achievements in the field of predict earthquake from remote sensing images have been obtained in the last few decades. But the traditional prediction methods presented do have the limitations of can't forecast epicenter location accurately and automatically. In order to solve the problem, a new predicting earthquakes method based on extract the texture and emergence frequency of the earthquake cloud is proposed in this paper. First, strengthen the infrared cloud images. Second, extract the texture feature vector of each pixel. Then, classified those pixels and converted to several small suspected area. Finally, tracking the suspected area and estimate the possible location. The inversion experiment of Ludian earthquake show that this approach can forecast the seismic center feasible and accurately.

  18. CloudSat Image of a Polar Night Storm Near Antarctica

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1

    CloudSat image of a horizontal cross-section of a polar night storm near Antarctica. Until now, clouds have been hard to observe in polar regions using remote sensing, particularly during the polar winter or night season. The red colors are indicative of highly reflective particles such as water (rain) or ice crystals, while the blue indicates thinner clouds (such as cirrus). The flat green/blue lines across the bottom represent the ground signal. The vertical scale on the CloudSat Cloud Profiling Radar image is approximately 30 kilometers (19 miles). The blue line below the Cloud Profiling Radar image indicates that the data were taken over water; the brown line below the image indicates the relative elevation of the land surface. The inset image shows the CloudSat track relative to a Moderate Resolution Imaging Spectroradiometer (MODIS) infrared image taken at nearly the same time.

  19. Modified control software for imaging ultracold atomic clouds

    SciTech Connect

    Whitaker, D. L.; Sharma, A.; Brown, J. M.

    2006-12-15

    A charge-coupled device (CCD) camera capable of taking high-quality images of ultracold atomic samples can often represent a significant portion of the equipment costs in atom trapping experiment. We have modified the commercial control software of a CCD camera designed for astronomical imaging to take absorption images of ultracold rubidium clouds. This camera is sensitive at 780 nm and has been modified to take three successive 16-bit images at full resolution. The control software can be integrated into a Matlab graphical user interface with fitting routines written as Matlab functions. This camera is capable of recording high-quality images at a fraction of the cost of similar cameras typically used in atom trapping experiments.

  20. Cloud based toolbox for image analysis, processing and reconstruction tasks.

    PubMed

    Bednarz, Tomasz; Wang, Dadong; Arzhaeva, Yulia; Lagerstrom, Ryan; Vallotton, Pascal; Burdett, Neil; Khassapov, Alex; Szul, Piotr; Chen, Shiping; Sun, Changming; Domanski, Luke; Thompson, Darren; Gureyev, Timur; Taylor, John A

    2015-01-01

    This chapter describes a novel way of carrying out image analysis, reconstruction and processing tasks using cloud based service provided on the Australian National eResearch Collaboration Tools and Resources (NeCTAR) infrastructure. The toolbox allows users free access to a wide range of useful blocks of functionalities (imaging functions) that can be connected together in workflows allowing creation of even more complex algorithms that can be re-run on different data sets, shared with others or additionally adjusted. The functions given are in the area of cellular imaging, advanced X-ray image analysis, computed tomography and 3D medical imaging and visualisation. The service is currently available on the website www.cloudimaging.net.au . PMID:25381109

  1. Radiometric normalization and cloud detection of optical satellite images using invariant pixels

    NASA Astrophysics Data System (ADS)

    Lin, Chao-Hung; Lin, Bo-Yi; Lee, Kuan-Yi; Chen, Yi-Chen

    2015-08-01

    Clouds in optical satellite images can be a source of information for water measurement or viewed as contaminations that obstruct landscape observations. Thus, the use of a cloud detection method that discriminates cloud and clear-sky pixels in images is necessary in remote sensing applications. With the aid of radiometric correction/normalization, previous methods utilized temporal and spectral information as well as cloud-free reference images to develop threshold-based cloud detection filters. Although this strategy can effectively identify cloud pixels, the detection accuracy mainly relies on the successful radiometric correction/normalization and reference image quality. Relative radiometric normalization generally suffers from cloud covers, while multi-temporal cloud detection is sensitive to the radiometric normalization quality. Thus, the current study proposes a method based on weighted invariant pixels for both processes. A set of invariant pixels is extracted from a time series of cloud-contaminated images by using the proposed weighted principle component analysis, after which multi-temporal images are normalized with the selected invariant pixels. In addition, a reference image is generated for each cloud-contaminated image using invariant pixels with a weighting scheme. In the experiments, image sequences acquired by the Landsat-7 Enhanced Thematic Mapper Plus sensor are analyzed qualitatively and quantitatively to evaluate the proposed method. Experimental results indicate that F-measures of cloud detections are improved by 1.1-6.9% using the generated reference images.

  2. An X-ray image of the large magellanic cloud

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.; Petre, R.

    1994-01-01

    We have used archival ROSAT Position Sensitive Proportional Counter (PSPC) pointed observations to construct maps of the Large Magellanic Cloud (LMC) in four energy bands between 0.5 and 2.0 keV. These represent the most complete, deepest, and most detailed X-ray images of the LMC to date. While confirming the general morphology of the diffuse LMC emission observed by Wang et al. with Einstein IPC data, these images reveal a wealth of detailed structure of high statistical significance on angular scales from a few arcminutes to a few degrees. In addition, at least twice as many discrete sources are detected as were found using the IPC.

  3. CloudSat First Image of a Warm Front Storm Over the Norwegian Sea

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1

    CloudSat's first image, of a warm front storm over the Norwegian Sea, was obtained on May 20, 2006. In this horizontal cross-section of clouds, warm air is seen rising over colder air as the satellite travels from right to left. The red colors are indicative of highly reflective particles such as water droplets (or rain) or larger ice crystals (or snow), while the blue indicates thinner clouds (such as cirrus). The flat green/blue lines across the bottom represent the ground signal. The vertical scale on the CloudSat Cloud Profiling Radar image is approximately 30 kilometers (19 miles). The blue line below the Cloud Profiling Radar image indicates that the data were taken over water. The inset image shows the CloudSat track relative to a Moderate Resolution Imaging Spectroradiometer (MODIS) infrared image taken at nearly the same time.

  4. Enabling outsourcing XDS for imaging on the public cloud.

    PubMed

    Ribeiro, Lus S; Rodrigues, Renato P; Costa, Carlos; Oliveira, Jos Lus

    2013-01-01

    Picture Archiving and Communication System (PACS) has been the main paradigm in supporting medical imaging workflows during the last decades. Despite its consolidation, the appearance of Cross-Enterprise Document Sharing for imaging (XDS-I), within IHE initiative, constitutes a great opportunity to readapt PACS workflow for inter-institutional data exchange. XDS-I provides a centralized discovery of medical imaging and associated reports. However, the centralized XDS-I actors (document registry and repository) must be deployed in a trustworthy node in order to safeguard patient privacy, data confidentiality and integrity. This paper presents XDS for Protected Imaging (XDS-p), a new approach to XDS-I that is capable of being outsourced (e.g. Cloud Computing) while maintaining privacy, confidentiality, integrity and legal concerns about patients' medical information. PMID:23920510

  5. Analysis of interstellar cloud structure based on IRAS images

    NASA Technical Reports Server (NTRS)

    Scalo, John M.

    1992-01-01

    The goal of this project was to develop new tools for the analysis of the structure of densely sampled maps of interstellar star-forming regions. A particular emphasis was on the recognition and characterization of nested hierarchical structure and fractal irregularity, and their relation to the level of star formation activity. The panoramic IRAS images provided data with the required range in spatial scale, greater than a factor of 100, and in column density, greater than a factor of 50. In order to construct densely sampled column density maps of star-forming clouds, column density images of four nearby cloud complexes were constructed from IRAS data. The regions have various degrees of star formation activity, and most of them have probably not been affected much by the disruptive effects of young massive stars. The largest region, the Scorpius-Ophiuchus cloud complex, covers about 1000 square degrees (it was subdivided into a few smaller regions for analysis). Much of the work during the early part of the project focused on an 80 square degree region in the core of the Taurus complex, a well-studied region of low-mass star formation.

  6. The Earth Clouds and Radiation Explorer (EarthCARE) Mission: Cloud and Aerosol Lidar and Imager algorithms.

    NASA Astrophysics Data System (ADS)

    Donovan, David; van Zadelhoff, Gerd-Jan; Wandinger, Ulla; Hnerbein, Anjah; Fischer, Jurgen; von Bismarck, Jonas; Eisinger, Michael; Lajas, Dulce; Wehr, Tobias

    2015-04-01

    The value of multi-sensor remote sensing applied to clouds and aerosol has become clear in recent years. For example, combinations of instruments including passive radiometers, lidars and cloud radars have proved invaluable for their ability to retrieve profiles of cloud macrophysical and microphysical properties. This is amply illustrated by various results from the US-DoE ARM (and similar) surface sites as well as results from data collected by sensors aboard the A-train satellites CloudSat, CALIPSO, and Terra. The Earth Clouds Aerosol and Radiation Explorer (EarthCARE) mission is a combined ESA/JAXA mission to be launched in 2018 which has been designed with sensor-synergy playing a key role. The mission consists of a cloud-profiling radar (CPR), a high-spectral resolution cloud/aerosol lidar (ATLID), a cloud/aerosol multi-spectral imager (MSI), and a three-view broad-band radiometer (BBR). The mission will deliver cloud, aerosol and radiation products focusing on horizontal scales ranging from 1 km to 10 km. EarthCARE data will be used in multiple ways ranging from model evaluation studies, to GCM-orientated cloud microphysical property parameterization development, to data assimilation activities. Recently a number of activities, funded by ESA, have kicked-off which will ultimately deliver operational algorithms for EarthCARE. One of these activities is the "Atmospheric Products from Imager and Lidar" (APRIL) project which focuses on the development of lidar, imager and combined lidar-imager cloud and aerosol algorithms. In this presentation an overview of the APRIL algorithms within the wider context of the planned EarthCARE processing chain will be given.

  7. High Quality Typhoon Cloud Image Restoration by Combining Genetic Algorithm with Contourlet Transform

    SciTech Connect

    Zhang Changjiang; Wang Xiaodong

    2008-11-06

    An efficient typhoon cloud image restoration algorithm is proposed. Having implemented contourlet transform to a typhoon cloud image, noise is reduced in the high sub-bands. Weight median value filter is used to reduce the noise in the contourlet domain. Inverse contourlet transform is done to obtain the de-noising image. In order to enhance the global contrast of the typhoon cloud image, in-complete Beta transform (IBT) is used to determine non-linear gray transform curve so as to enhance global contrast for the de-noising typhoon cloud image. Genetic algorithm is used to obtain the optimal gray transform curve. Information entropy is used as the fitness function of the genetic algorithm. Experimental results show that the new algorithm is able to well enhance the global for the typhoon cloud image while well reducing the noises in the typhoon cloud image.

  8. Pattern recognition of clouds and ice in polar regions

    NASA Technical Reports Server (NTRS)

    Welch, R. M.; Sengupta, S. K.; Sundar, C. A.; Kuo, K. S.; Carsey, F. D.

    1990-01-01

    The study is based on AVHRR imagery and results from Landsat high-spatial-resolution scenes. Among the textual features investigated are the gray level difference vector (GLDV), and sum and difference histogram (SADH) approaches as well as gray level run length, spatial-coherence, and spectral-histogram measures. The traditional stepwise discriminant analysis and neural-network analysis are used for the identification of 20 Arctic surface and cloud classes. A principal-component analysis and hybrid architecture employing a modularized competitive learning layer are utilized. It is pointed out that the cloud-classification accuracy comparable to that of back-propagation could be achieved with a training time two orders of magnitude faster.

  9. A Routing Mechanism for Cloud Outsourcing of Medical Imaging Repositories.

    PubMed

    Godinho, Tiago Marques; Viana-Ferreira, Carlos; Bastiao Silva, Luis A; Costa, Carlos

    2016-01-01

    Web-based technologies have been increasingly used in picture archive and communication systems (PACS), in services related to storage, distribution, and visualization of medical images. Nowadays, many healthcare institutions are outsourcing their repositories to the cloud. However, managing communications between multiple geo-distributed locations is still challenging due to the complexity of dealing with huge volumes of data and bandwidth requirements. Moreover, standard methodologies still do not take full advantage of outsourced archives, namely because their integration with other in-house solutions is troublesome. In order to improve the performance of distributed medical imaging networks, a smart routing mechanism was developed. This includes an innovative cache system based on splitting and dynamic management of digital imaging and communications in medicine objects. The proposed solution was successfully deployed in a regional PACS archive. The results obtained proved that it is better than conventional approaches, as it reduces remote access latency and also the required cache storage space. PMID:25343773

  10. Reflections on current and future applications of multiangle imaging to aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, David

    2010-05-01

    The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global Earth data from NASA's Terra satellite since February 2000. With its 9 along-track view angles, 4 spectral bands, intrinsic spatial resolution of 275 m, and stable radiometric and geometric calibration, no instrument that combines MISR's attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. Multiangle imaging offers several tools for remote sensing of aerosol and cloud properties, including bidirectional reflectance and scattering measurements, stereoscopic pattern matching, time lapse sequencing, and potentially, optical tomography. Current data products from MISR employ several of these techniques. Observations of the intensity of scattered light as a function of view angle and wavelength provide accurate measures of aerosol optical depths (AOD) over land, including bright desert and urban source regions. Partitioning of AOD according to retrieved particle classification and incorporation of height information improves the relationship between AOD and surface PM2.5 (fine particulate matter, a regulated air pollutant), constituting an important step toward a satellite-based particulate pollution monitoring system. Stereoscopic cloud-top heights provide a unique metric for detecting interannual variability of clouds and exceptionally high quality and sensitivity for detection and height retrieval for low-level clouds. Using the several-minute time interval between camera views, MISR has enabled a pole-to-pole, height-resolved atmospheric wind measurement system. Stereo imagery also makes possible global measurement of the injection heights and advection speeds of smoke plumes, volcanic plumes, and dust clouds, for which a large database is now available. To build upon what has been learned during the first decade of MISR observations, we are evaluating algorithm updates that not only refine retrieval accuracies but also include enhancements (e.g., finer spatial resolution) that would have been computationally prohibitive just ten years ago. In addition, we are developing technological building blocks for future sensors that enable broader spectral coverage, wider swath, and incorporation of high-accuracy polarimetric imaging. Prototype cameras incorporating photoelastic modulators have been constructed. To fully capitalize on the rich information content of the current and next-generation of multiangle imagers, several algorithmic paradigms currently employed need to be re-examined, e.g., the use of aerosol look-up tables, neglect of 3-D effects, and binary partitioning of the atmosphere into "cloudy" or "clear" designations. Examples of progress in algorithm and technology developments geared toward advanced application of multiangle imaging to remote sensing of aerosols and clouds will be presented.

  11. Characterizing Spatial Patterns of Cloud Cover And Fog Inundation in the California Channel Islands

    NASA Astrophysics Data System (ADS)

    Rastogi, B.; Fischer, D. T.; Williams, P.; Iacobellis, S.; McEachern, K.; Still, C. J.

    2013-12-01

    Coastal forests in Mediterranean climates are frequently covered by clouds or immersed in fog. Previous studies suggest that clouds strongly modulate forest distributions as well as carbon and water budgets in these semi-arid environments. Both low level stratocumulus cloud cover and fog can enhance the water status of vegetation along the Californian coast and the Channel Islands by reducing insolation and raising relative humidity and thus reducing evapotranspiration, while also potentially supplying water directly to the landscape from fog-drip during otherwise warm and rainless summers. While cloud cover and fog can ameliorate summer drought stress and enhance soil water budgets, they often have different spatial and temporal patterns. The resulting shifts in relative ecological importance of fog and stratus are largely unknown. The overall objective of this project was to map spatial and temporal distributions of daytime cloud cover frequency for the California Channel Islands, and to predict probabilities of surface cloud (fog) contact and immersion for these islands. Daytime cloud cover maps were generated for the northern Channel Islands using GOES satellite imagery for the years 1996-2012. To discriminate fog from stratus the base of the cloud height was constrained by using airport cloud ceiling data and topographic information. In order to observe variation in fog frequency at scales relevant to species distributions on the Channel Islands the native GOES resolution was downscaled by using radiosonde and reanalysis data. Satellite derived estimates of cloud cover and fog were correlated with field measurements of insolation, fog drip and leaf wetness on Santa Rosa and Santa Cruz islands. This enabled spatial and temporal extrapolation to understand seasonal and inter-annual variations in cloud cover frequency and fog inundation and drip and will be important for future water balance modeling, studies of coastal vegetation distributions and for better identification of locations where native vegetation restoration efforts are likely to be most successful.

  12. Radar imaging of ocean surface patterns

    NASA Technical Reports Server (NTRS)

    Brown, W. E., Jr.; Elachi, C.; Thompson, T. W.

    1976-01-01

    The paper presents some examples of imaging radar oceanographic observations and discusses physical phenomena on the surface that may cause the radar image. The different ocean scattering theories are briefly discussed, including the tangent plane model, the Bragg-Rice model, and the Rayleigh scattering model. All but one of the images presented were obtained with an L-band HH-polarized radar; they include deep-ocean swells, coastal swells, wave refractions, internal waves, ship wakes, abrupt transitions in open-ocean surface roughness, surface slicks, island wind shadowing, and currents. Analyses are shown to suggest that the primary source of the L-band imagery of ocean surface patterns is the variation of small-scale surface roughness and local tilt angle. It is also noted that surface irregularities behave as isotropic scatterers for a radar wavelength of 25 cm.

  13. Ice Cloud Optical Depth Retrievals from CRISM Multispectral Images

    NASA Astrophysics Data System (ADS)

    Klassen, David R.

    2014-11-01

    One set of data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Mars Reconnaissance Orbiter (MRO) is the multispectral survey that measured the visible-through-near-infrared reflectance of the entire planet of Mars at specific wavelengths. The spectral data from several sols were be combined to create multi-spectral maps of Mars. In addition, these maps can be zonally averaged to create a latitude vs season image cube of Mars. All of these image cubes can be fit using a full radiative transfer modeling in order to retrieve ice cloud optical depthas a map for one of the particular dates, or as a latitude vs season record.To compare the data radiative transfer models, a measure of the actual surface reflectance is needed. There are several possible ways to model this, such as using a nearby region that is "close enough" or by looking at the same region at different times and assuming one of those is the actual surface reflectance. Neither of these is ideal for trying to process an entire map of data because aerosol clouds can be fairly extensive both spatially and temporally.Another technique is to assume that the surface can be modeled as a linear combination of a limited set of intrinsic spectral endmembers. A combination of Principal Component Analysis (PCA) and Target Transformation (TT) has been used to recover just such a set of spectral endmember shapes. The coefficients in the linear combination then become additional fitting parameters in the radiative transfer modeling of each map pointall parameters are adjusted until the RMS error between the model and the data is minimized. Based on previous work, the PCA of martian spectral image cubes is relatively consistent regardless of season, implying the underlying, large-scale, intrinsic traits that dominate the data variance are relatively constant. These overall PCA results can then be used to create a single set of spectral endmembers that can be used for any of the data cubes.Presented here are the results of this PCA/TT work to find the singular set of spectral endmembers and their use in recovering ice cloud optical depth from the MRO-CRISM multispectral image cubes.

  14. Medical image segmentation using object atlas versus object cloud models

    NASA Astrophysics Data System (ADS)

    Phellan, Renzo; Falcão, Alexandre X.; Udupa, Jayaram K.

    2015-03-01

    Medical image segmentation is crucial for quantitative organ analysis and surgical planning. Since interactive segmentation is not practical in a production-mode clinical setting, automatic methods based on 3D object appearance models have been proposed. Among them, approaches based on object atlas are the most actively investigated. A key drawback of these approaches is that they require a time-costly image registration process to build and deploy the atlas. Object cloud models (OCM) have been introduced to avoid registration, considerably speeding up the whole process, but they have not been compared to object atlas models (OAM). The present paper fills this gap by presenting a comparative analysis of the two approaches in the task of individually segmenting nine anatomical structures of the human body. Our results indicate that OCM achieve a statistically significant better accuracy for seven anatomical structures, in terms of Dice Similarity Coefficient and Average Symmetric Surface Distance.

  15. Image transfer through cirrus clouds. I. Ray trace analysis and wave-front reconstruction.

    PubMed

    Landesman, B T; Kindilien, P J; Matson, C L; Caudill, T R

    2000-10-20

    A new technique for modeling image transfer through cirrus clouds is presented. The technique uses a ray trace to model beam propagation through a three-dimensional volume of polydisperse, hexagonal ice crystals. Beyond the cloud, the technique makes use of standard Huygens-Fresnel propagation methods. At the air-cloud interface, each wave front is resolved into a ray distribution for input to the ray trace software. Similarly, a wave front is reconstructed from the output ray distribution at the cloud-air interface. Simulation output from the ray trace program is presented and the modulation transfer function for stars imaged through cirrus clouds of varying depths is discussed. PMID:18354542

  16. A structural-stochastic model for the analysis and synthesis of cloud images

    NASA Technical Reports Server (NTRS)

    Garand, L.; Weinman, J. A.

    1986-01-01

    A structural-stochastic image model is developed for the analysis and synthesis of cloud images. The ability of the model to characterize the visual appearance of cloud fields observed by satellite with a limited number of parameters is demonstrated. The model merges structural and stochastic information, the stochastic model acting as a local statistical operator applied to the output of the structural model. The structural or large-scale organization of the scene is retrieved from the two-dimensional Fourier representation of the digital image. The pattern generated by the major Fourier components provides a first guess of the scene. The stochastic aspect is described by a Markov model of texture that assumes a binomial probability distribution for the local grey-level variability. This Markov model provides four parameters that represent the clustering strength in the horizontal, vertical and diagonal directions. These parameters are estimated by a standard maximum-likelihood technique. The image can be reproduced with a fair degree of verisimilitude from these parameters. The data compression factor is of the order of one hundred to several hundreds.

  17. Congruence analysis of point clouds from unstable stereo image sequences

    NASA Astrophysics Data System (ADS)

    Jepping, C.; Bethmann, F.; Luhmann, T.

    2014-06-01

    This paper deals with the correction of exterior orientation parameters of stereo image sequences over deformed free-form surfaces without control points. Such imaging situation can occur, for example, during photogrammetric car crash test recordings where onboard high-speed stereo cameras are used to measure 3D surfaces. As a result of such measurements 3D point clouds of deformed surfaces are generated for a complete stereo sequence. The first objective of this research focusses on the development and investigation of methods for the detection of corresponding spatial and temporal tie points within the stereo image sequences (by stereo image matching and 3D point tracking) that are robust enough for a reliable handling of occlusions and other disturbances that may occur. The second objective of this research is the analysis of object deformations in order to detect stable areas (congruence analysis). For this purpose a RANSAC-based method for congruence analysis has been developed. This process is based on the sequential transformation of randomly selected point groups from one epoch to another by using a 3D similarity transformation. The paper gives a detailed description of the congruence analysis. The approach has been tested successfully on synthetic and real image data.

  18. Microwave Imager Measures Sea Surface Temperature Through Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image was acquired over Tropical Atlantic and U.S. East Coast regions on Aug. 22 - Sept. 23, 1998. Cloud data were collected by the Geostationary Operational Environmental Satellite (GOES). Sea Surface Temperature (SST) data were collected aboard the NASA/NASDA Tropical Rainfall Measuring Mission (TRMM) satellite by The TRMM Microwave Imager (TMI). TMI is the first satellite microwave sensor capable of accurately measuring sea surface temperature through clouds, as shown in this scene. For years scientists have known there is a strong correlation between sea surface temperature and the intensity of hurricanes. But one of the major stumbling blocks for forecasters has been the precise measurement of those temperatures when a storm begins to form. In this scene, clouds have been made translucent to allow an unobstructed view of the surface. Notice Hurricane Bonnie approaching the Carolina Coast (upper left) and Hurricane Danielle following roughly in its path (lower right). The ocean surface has been falsely colored to show a map of water temperature--dark blues are around 75oF, light blues are about 80oF, greens are about 85oF, and yellows are roughly 90oF. A hurricane gathers energy from warm waters found at tropical latitudes. In this image we see Hurricane Bonnie cross the Atlantic, leaving a cooler trail of water in its wake. As Hurricane Danielle followed in Bonnie's path, the wind speed of the second storm dropped markedly, as available energy to fuel the storm dropped off. But when Danielle left Bonnie's wake, wind speeds increased due to temperature increases in surface water around the storm. As a hurricane churns up the ocean, it's central vortex draws surface heat and water into the storm. That suction at the surface causes an upwelling of deep water. At depth, tropical ocean waters are significantly colder than water found near the surface. As they're pulled up to meet the storm, those colder waters essentially leave a footprint in the storm's wake which might last as long as two weeks. Forecasters can quantify the difference in surface temperatures between this footprint and the surrounding temperatures and use that information to better predict storm intensity. If another storm intersects with this cold water trail, it is likely to lose significant strength due to the fact that the colder water does not contain as much potential energy as warm water. TRMM Fact Sheet Predicting Hurricane Intensity Far from Land Remote Sensing Systems Image courtesy TRMM Project, Remote Sensing Systems, and Scientific Visualization Studio, NASA Goddard Space Flight Center

  19. Statistical pattern recognition algorithms for autofluorescence imaging

    NASA Astrophysics Data System (ADS)

    Kulas, Zbigniew; Bere?-Pawlik, El?bieta; Wierzbicki, Jaros?aw

    2009-02-01

    In cancer diagnostics the most important problems are the early identification and estimation of the tumor growth and spread in order to determine the area to be operated. The aim of the work was to design of statistical algorithms helping doctors to objectively estimate pathologically changed areas and to assess the disease advancement. In the research, algorithms for classifying endoscopic autofluorescence images of larynx and intestine were used. The results show that the statistical pattern recognition offers new possibilities for endoscopic diagnostics and can be of a tremendous help in assessing the area of the pathological changes.

  20. Astronomy In The Cloud: Using Mapreduce For Image Coaddition

    NASA Astrophysics Data System (ADS)

    Wiley, Keith; Connolly, A.; Gardner, J.; Krughoff, S.; Balazinska, M.; Howe, B.; Kwon, Y.; Bu, Y.

    2011-01-01

    In the coming decade, astronomical surveys of the sky will generate tens of terabytes of images and detect hundreds of millions of sources every night. The study of these sources will involve computational challenges such as anomaly detection, classification, and moving object tracking. Since such studies require the highest quality data, methods such as image coaddition, i.e., registration, stacking, and mosaicing, will be critical to scientific investigation. With a requirement that these images be analyzed on a nightly basis to identify moving sources, e.g., asteroids, or transient objects, e.g., supernovae, these datastreams present many computational challenges. Given the quantity of data involved, the computational load of these problems can only be addressed by distributing the workload over a large number of nodes. However, the high data throughput demanded by these applications may present scalability challenges for certain storage architectures. One scalable data-processing method that has emerged in recent years is MapReduce, and in this paper we focus on its popular open-source implementation called Hadoop. In the Hadoop framework, the data is partitioned among storage attached directly to worker nodes, and the processing workload is scheduled in parallel on the nodes that contain the required input data. A further motivation for using Hadoop is that it allows us to exploit cloud computing resources, i.e., platforms where Hadoop is offered as a service. We report on our experience implementing a scalable image-processing pipeline for the SDSS imaging database using Hadoop. This multi-terabyte imaging dataset provides a good testbed for algorithm development since its scope and structure approximate future surveys. First, we describe MapReduce and how we adapted image coaddition to the MapReduce framework. Then we describe a number of optimizations to our basic approach and report experimental results compring their performance. This work is funded by the NSF and by NASA.

  1. Analysis of Point Cloud Generation from UAS Images

    NASA Astrophysics Data System (ADS)

    Ostrowski, S.; Jóźków, G.; Toth, C.; Vander Jagt, B.

    2014-11-01

    Unmanned Aerial Systems (UAS) allow for the collection of low altitude aerial images, along with other geospatial information from a variety of companion sensors. The images can then be processed using sophisticated algorithms from the Computer Vision (CV) field, guided by the traditional and established procedures from photogrammetry. Based on highly overlapped images, new software packages which were specifically developed for UAS technology can easily create ground models, such as Point Clouds (PC), Digital Surface Model (DSM), orthoimages, etc. The goal of this study is to compare the performance of three different software packages, focusing on the accuracy of the 3D products they produce. Using a Nikon D800 camera installed on an ocotocopter UAS platform, images were collected during subsequent field tests conducted over the Olentangy River, north from the Ohio State University campus. Two areas around bike bridges on the Olentangy River Trail were selected because of the challenge the packages would have in creating accurate products; matching pixels over the river and dense canopy on the shore presents difficult scenarios to model. Ground Control Points (GCP) were gathered at each site to tie the models to a local coordinate system and help assess the absolute accuracy for each package. In addition, the models were also relatively compared to each other using their PCs.

  2. Aerosol patterns and aerosol-cloud-interactions off the West African Coast based on the A-train formation

    NASA Astrophysics Data System (ADS)

    Fuchs, Julia; Bendix, Jrg; Cermak, Jan

    2013-04-01

    In this study, spatial and temporal aerosol patterns off the Western African coast are characterized and related to cloud properties, based on satellite data Atmospheric aerosols play a key role in atmospheric processes and influence our environmental system in a complex way. Their identification, characterization, transport patterns as well as their interactions with clouds pose major challenges. Especially the last aspect reveals major uncertainties in terms of the Earth's radiation budget as reported in the IPCC's Fourth Assessment Report (IPCC, 2007). Western and Southern Africa are dominated by two well-known source types of atmospheric aerosols. First, the Saharan Desert is the world's largest aeolian dust emitting source region. Second, biomass burning aerosol is commonly transported off-shore further south (Kaufman et al., 2005). Both aerosol types influence Earth's climate in different manners and can be detected by the MODIS (MODerate resolution Imaging Spectrometer) sensor onboard the EOS platforms as they propagate to the Central and Southern Atlantic. The motivation of this study was to reveal the seasonal pattern of the Saharan dust transport based on an observation period of 11 years and trying to explain the meteorological mechanisms. North African dust plumes are transported along a latitude of 19N in July and 6N in January. The seasonally fluctuating intensities adapt to the annual cycle of wind and precipitation regimes. A strong relationship is found between the spatial shift of the Azores High and the Saharan dust load over the middle Atlantic Ocean. Monthly Aerosol Optical Thickness products of Terra MODIS and NCEP-DOE (National Centers for Environmental Predictions) Reanalysis II data are used for this purpose. The relationship between aerosol and cloud droplet parameters is blurred by high sensitivities to aerosol size and composition (Feingold, 2003; McFiggans et al., 2006) as well as meteorological context (Ackerman et al., 2004). Satellite data from the A-train formation, including the Aqua, CloudSat and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) are used to analyze aerosol-cloud-interactions in detail, along with re-analysis data to constrain by meteorological conditions. Information about the vertical and geographical distribution of different aerosol types and cloud parameters will lead to a process-oriented understanding of these issues on a regional scale. Ackerman, A., Kirkpatrick, M., Stevens, D., & Toon, O. (2004). The impact of humidity above stratiform clouds on indirect aerosol climate forcing. Nature, 432(December), 1014-1017. doi:10.1038/nature03137.1. Feingold, G. (2003). First measurements of the Twomey indirect effect using ground-based remote sensors. Geophysical Research Letters, 30(6), 1287. doi:10.1029/2002GL016633 IPCC. (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working group I to the Fourth Assessment Report of the Interfovernmental Panel on climate Change. Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Kaufman, Y. J., Koren, I., Remer, L. A., Tanr, D., Ginoux, P., & Fan, S. (2005). Dust transport and deposition observed from the Terra-Moderate Resolution Imaging Spectroradiometer (MODIS) spacecraft over the Atlantic Ocean. Journal of Geophysical Research, 110(D10), 1-16. doi:10.1029/2003JD004436 McFiggans, G., Artaxo, P., Baltensperger, U., Coe, H., Facchini, M. C., Feingold, G., Fuzzi, S., et al. (2006). The effect of physical and chemical aerosol properties on warm cloud droplet activation. Atmospheric Chemistry and Physics, 6(9), 2593-2649. doi:10.5194/acp-6-2593-2006

  3. High resolution (375 m) cloud microstructure as seen from the NPP/VIIRS Satellite imager

    NASA Astrophysics Data System (ADS)

    Rosenfeld, D.; Liu, G.; Yu, X.; Zhu, Y.; Dai, J.; Xu, X.; Yue, Z.

    2013-11-01

    The VIIRS (Visible Infrared Imaging Radiometer Suite) onboard the Suomi NPP (National Polar-Orbiting Partnership) satellite has improved resolution of 750 m with respect to 1000 m of the MODerate-resolution Imaging Spectroradiometer, for the channels that allow retrieving cloud microphysical parameters such as cloud drop effective radius (re). The VIIRS has also an imager with 5 channels of double resolution of 375 m, which was not designed for retrieving cloud products. A methodology for a high resolution retrieval of re and microphysical presentation of the cloud field based on the VIIRS imager was developed and evaluated with respect to MODIS in this study. The tripled microphysical resolution with respect to MODIS allows obtaining new insights for cloud aerosol interactions, especially at the smallest cloud scales, because the VIIRS imager can resolve the small convective elements that are sub-pixel for MODIS cloud products. Examples are given for new insights on ship tracks in marine stratocumulus, pollution tracks from point and diffused sources in stratocumulus and cumulus clouds over land, deep tropical convection in pristine air mass over ocean and land, tropical clouds that develop in smoke from forest fires and in heavy pollution haze over densely populated regions in southeast Asia, and for pyro-cumulonimbus clouds. It is found that the VIIRS imager provides more robust physical interpretation and refined information for cloud and aerosol microphysics as compared to MODIS, especially in the initial stage of cloud formation. VIIRS is found to identify much more full-cloudy pixels when small boundary layer convective elements are present. This, in turn, allows a better quantification of cloud aerosol interactions and impacts on precipitation forming processes.

  4. High-resolution (375 m) cloud microstructure as seen from the NPP/VIIRS satellite imager

    NASA Astrophysics Data System (ADS)

    Rosenfeld, D.; Liu, G.; Yu, X.; Zhu, Y.; Dai, J.; Xu, X.; Yue, Z.

    2014-03-01

    VIIRS (Visible Infrared Imaging Radiometer Suite), onboard the Suomi NPP (National Polar-orbiting Partnership) satellite, has an improved resolution of 750 m with respect to the 1000 m of the Moderate Resolution Imaging Spectroradiometer for the channels that allow retrieving cloud microphysical parameters such as cloud drop effective radius (re). VIIRS also has an imager with five channels of double resolution of 375 m, which was not designed for retrieving cloud products. A methodology for a high-resolution retrieval of re and microphysical presentation of the cloud field based on the VIIRS imager was developed and evaluated with respect to MODIS in this study. The tripled microphysical resolution with respect to MODIS allows obtaining new insights for cloud-aerosol interactions, especially at the smallest cloud scales, because the VIIRS imager can resolve the small convective elements that are sub-pixel for MODIS cloud products. Examples are given for new insights into ship tracks in marine stratocumulus, pollution tracks from point and diffused sources in stratocumulus and cumulus clouds over land, deep tropical convection in pristine air mass over ocean and land, tropical clouds that develop in smoke from forest fires and in heavy pollution haze over densely populated regions in southeastern Asia, and for pyro-cumulonimbus clouds. It is found that the VIIRS imager provides more robust physical interpretation and refined information for cloud and aerosol microphysics as compared to MODIS, especially in the initial stage of cloud formation. VIIRS is found to identify significantly more fully cloudy pixels when small boundary layer convective elements are present. This, in turn, allows for a better quantification of cloud-aerosol interactions and impacts on precipitation-forming processes.

  5. How consistent are precipitation patterns predicted by GCMs in the absence of cloud radiative effects?

    NASA Astrophysics Data System (ADS)

    Popke, Dagmar; Bony, Sandrine; Mauritsen, Thorsten; Stevens, Bjorn

    2015-04-01

    Model simulations with state-of-the-art general circulation models reveal a strong disagreement concerning the simulated regional precipitation patterns and their changes with warming. The deviating precipitation response even persists when reducing the model experiment complexity to aquaplanet simulation with forced sea surface temperatures (Stevens and Bony, 2013). To assess feedbacks between clouds and radiation on precipitation responses we analyze data from 5 models performing the aquaplanet simulations of the Clouds On Off Klima Intercomparison Experiment (COOKIE), where the interaction of clouds and radiation is inhibited. Although cloud radiative effects are then disabled, the precipitation patterns among models are as diverse as with cloud radiative effects switched on. Disentangling differing model responses in such simplified experiments thus appears to be key to better understanding the simulated regional precipitation in more standard configurations. By analyzing the local moisture and moist static energy budgets in the COOKIE experiments we investigate likely causes for the disagreement among models. References Stevens, B. & S. Bony: What Are Climate Models Missing?, Science, 2013, 340, 1053-1054

  6. Image pattern recognition supporting interactive analysis and graphical visualization

    NASA Technical Reports Server (NTRS)

    Coggins, James M.

    1992-01-01

    Image Pattern Recognition attempts to infer properties of the world from image data. Such capabilities are crucial for making measurements from satellite or telescope images related to Earth and space science problems. Such measurements can be the required product itself, or the measurements can be used as input to a computer graphics system for visualization purposes. At present, the field of image pattern recognition lacks a unified scientific structure for developing and evaluating image pattern recognition applications. The overall goal of this project is to begin developing such a structure. This report summarizes results of a 3-year research effort in image pattern recognition addressing the following three principal aims: (1) to create a software foundation for the research and identify image pattern recognition problems in Earth and space science; (2) to develop image measurement operations based on Artificial Visual Systems; and (3) to develop multiscale image descriptions for use in interactive image analysis.

  7. Imaging fictive locomotor patterns in larval Drosophila

    PubMed Central

    Bayley, Timothy G.; Taylor, Adam L.; Berni, Jimena; Bate, Michael; Hedwig, Berthold

    2015-01-01

    We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca2+ indicators. The Ca2+ signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca2+ signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca2+ signals were normally initiated did not eliminate production of Ca2+ waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques. PMID:26311188

  8. Imaging fictive locomotor patterns in larval Drosophila.

    PubMed

    Pulver, Stefan R; Bayley, Timothy G; Taylor, Adam L; Berni, Jimena; Bate, Michael; Hedwig, Berthold

    2015-11-01

    We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca(2+) indicators. The Ca(2+) signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca(2+) signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca(2+) signals were normally initiated did not eliminate production of Ca(2+) waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques. PMID:26311188

  9. VizieR Online Data Catalog: IRAS images of nearby dark clouds (Wood+ 1994)

    NASA Astrophysics Data System (ADS)

    Wood, D. O. S.; Myers, P. C.; Daugherty, D. A.

    1997-03-01

    We have investigated ~100 nearby molecular clouds using the extensive, all-sky database of IRAS. The clouds in this study cover a wide range of physical properties including visual extinction, size, mass, degree of isolation, homogeneity and morphology. IRAS 100 and 60 micrometre co-added images were used to calculate the 100 micrometre optical depth of dust in the clouds. These images of dust optical depth compare very well with 12CO and 13CO observations, and can be related to H2 column density. From the optical depth images we locate the edges of dark clouds and the dense cores inside them. We have identified a total of 43 "IRAS clouds" (regions with Av>2) which contain a total of 255 "IRAS cores" (regions with Av>4) and we catalog their physical properties. We find that the clouds are remarkably filamentary, and that the cores within the clouds are often distributed along the filaments. The largest cores are usually connected to other large cores by filaments. We have developed selection criteria to search the IRAS Point Source Catalog for stars that are likely to be associated with the clouds and we catalog the IRAS sources in each cloud or core. Optically visible stars associated with the clouds have been identified from the Herbig and Bell catalog. From these data we characterize the physical properties of the clouds including their star-formation efficiency. (4 data files).

  10. An automated cloud detection method based on the green channel of total-sky visible images

    NASA Astrophysics Data System (ADS)

    Yang, J.; Min, Q.; Lu, W.; Yao, W.; Ma, Y.; Du, J.; Lu, T.; Liu, G.

    2015-11-01

    Obtaining an accurate cloud-cover state is a challenging task. In the past, traditional two-dimensional red-to-blue band methods have been widely used for cloud detection in total-sky images. By analyzing the imaging principle of cameras, the green channel has been selected to replace the 2-D red-to-blue band for detecting cloud pixels from partly cloudy total-sky images in this study. The brightness distribution in a total-sky image is usually nonuniform, because of forward scattering and Mie scattering of aerosols, which results in increased detection errors in the circumsolar and near-horizon regions. This paper proposes an automatic cloud detection algorithm, "green channel background subtraction adaptive threshold" (GBSAT), which incorporates channel selection, background simulation, computation of solar mask and cloud mask, subtraction, an adaptive threshold, and binarization. Five experimental cases show that the GBSAT algorithm produces more accurate retrieval results for all these test total-sky images.

  11. A Cloud-Tracking Tool For Planetary Orbiter Images

    NASA Astrophysics Data System (ADS)

    Gil, R.; Luz, D.; Berry, D.; Roos-Serote, M.

    2005-08-01

    During their operations phase, planetary missions continuously produce a wealth of data that tend to overwhelm research teams. Spectral imagers, in particular, produce data cubes in which the wavelength dimension adds to the two spatial dimensions. Tracking of atmospheric features in order to derive winds and the construction of global maps from such large data volumes becomes particularly time-consuming if done manually. This highlights the importance of automated procedures capable of analysing sequences of data cubes with minimal user interaction. A tool for cloud tracking for such a purpose is currently under development in our group. In its present state it is based on synthetic images and uses a simple method of multiple matrix comparison to derive wind components. Deriving winds from data from the Venus Express - Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) instrument will be a possible application. We shall present an overview of the method, its benchmarking and the current status and future development of the project. [R. Gil is currently supported by Fundacao para a Ciencia e a Tecnologia, Portugal, project PDCTU/FNU/49822/2003. D. Luz acknowledges support from FCT, grant SFRH-BPD-3630-2000.

  12. The analysis of polar clouds from AVHRR satellite data using pattern recognition techniques

    NASA Technical Reports Server (NTRS)

    Smith, William L.; Ebert, Elizabeth

    1990-01-01

    The cloud cover in a set of summertime and wintertime AVHRR data from the Arctic and Antarctic regions was analyzed using a pattern recognition algorithm. The data were collected by the NOAA-7 satellite on 6 to 13 Jan. and 1 to 7 Jul. 1984 between 60 deg and 90 deg north and south latitude in 5 spectral channels, at the Global Area Coverage (GAC) resolution of approximately 4 km. This data embodied a Polar Cloud Pilot Data Set which was analyzed by a number of research groups as part of a polar cloud algorithm intercomparison study. This study was intended to determine whether the additional information contained in the AVHRR channels (beyond the standard visible and infrared bands on geostationary satellites) could be effectively utilized in cloud algorithms to resolve some of the cloud detection problems caused by low visible and thermal contrasts in the polar regions. The analysis described makes use of a pattern recognition algorithm which estimates the surface and cloud classification, cloud fraction, and surface and cloudy visible (channel 1) albedo and infrared (channel 4) brightness temperatures on a 2.5 x 2.5 deg latitude-longitude grid. In each grid box several spectral and textural features were computed from the calibrated pixel values in the multispectral imagery, then used to classify the region into one of eighteen surface and/or cloud types using the maximum likelihood decision rule. A slightly different version of the algorithm was used for each season and hemisphere because of differences in categories and because of the lack of visible imagery during winter. The classification of the scene is used to specify the optimal AVHRR channel for separating clear and cloudy pixels using a hybrid histogram-spatial coherence method. This method estimates values for cloud fraction, clear and cloudy albedos and brightness temperatures in each grid box. The choice of a class-dependent AVHRR channel allows for better separation of clear and cloudy pixels than does a global choice of a visible and/or infrared threshold. The classification also prevents erroneous estimates of large fractional cloudiness in areas of cloudfree snow and sea ice. The hybrid histogram-spatial coherence technique and the advantages of first classifying a scene in the polar regions are detailed. The complete Polar Cloud Pilot Data Set was analyzed and the results are presented and discussed.

  13. Differently patterned airflows induced by 1-kHz femtosecond laser filaments in a cloud chamber

    NASA Astrophysics Data System (ADS)

    Sun, Haiyi; Liang, Hong; Liu, Yonghong; Ju, Jingjing; Wei, Yingxia; Wang, Cheng; Wang, Tiejun; Liu, Jiansheng; Chin, See Leang; Li, Ruxin; Xu, Zhizhan

    2015-11-01

    Airflow induced by femtosecond laser (800 nm/1 kHz/25 fs) filamentation with different lengths was investigated in a laboratory cloud chamber. Various filament lengths were generated by adjusting laser energy and lens focal length. It was found that airflow patterns are closely related to filament intensity and length. Intense and long filaments are beneficial in updraft generation with large vortices above the filament, while intense and short filaments tend to promote the formation of well-contacted vortices below the filament. Differently patterned airflows induced elliptical snow piles with different masses. We simulated airflow in a cloud chamber numerically taking laser filaments as heat sources. The mechanisms of differently patterned airflow and snow formation induced by filaments were discussed.

  14. Cloud Optical Depth Measured with Ground-Based, Uncooled Infrared Imagers

    NASA Technical Reports Server (NTRS)

    Shaw, Joseph A.; Nugent, Paul W.; Pust, Nathan J.; Redman, Brian J.; Piazzolla, Sabino

    2012-01-01

    Recent advances in uncooled, low-cost, long-wave infrared imagers provide excellent opportunities for remotely deployed ground-based remote sensing systems. However, the use of these imagers in demanding atmospheric sensing applications requires that careful attention be paid to characterizing and calibrating the system. We have developed and are using several versions of the ground-based "Infrared Cloud Imager (ICI)" instrument to measure spatial and temporal statistics of clouds and cloud optical depth or attenuation for both climate research and Earth-space optical communications path characterization. In this paper we summarize the ICI instruments and calibration methodology, then show ICI-derived cloud optical depths that are validated using a dual-polarization cloud lidar system for thin clouds (optical depth of approximately 4 or less).

  15. Textural analysis for the detection of dust clouds from infrared satellite images

    NASA Astrophysics Data System (ADS)

    Diop, Oumar; Kpalma, Kidiyo; Ronsin, Joseph

    2006-12-01

    The remote sensing constitutes a vast field of study whose repercussions are many and varied on environmental management. The phenomenon of dust clouds is a major climatic event in Africa. But the observation means of this phenomenon are still too much limited. The development of an approach consisting in the detection of dust clouds from satellite images can be a solution. In this work, we present a new approach for dust clouds detection in the infrared images coming from the METEOSAT satellite. It is then proved necessary of finding automatic or semi-automatic analysis methods to assist their detection and interpretation. Thus we are interested in image fusion methods for detection structures in the images. In this paper, we present some statistical methods which enable to extract texture features from the images. Then, we describe the method used for selection the best attributes for the images segmentation into three classes: "water clouds", "ocean" and "continent". We then use a method which enable us to segment the class "continent" of the image for dust clouds detection. Finally, we compare our results with another one which shows the zone of presence or absence of dust clouds. This comparison shows that we are in concord because visually, we have a good analogy of shape on the dust clouds zone as well as on the part without dust clouds.

  16. Analyzing and processing the images of self-organized patterns

    NASA Astrophysics Data System (ADS)

    Yang, Xiaohong; Liu, Shuhua

    2009-05-01

    Some practical methods are presented for analyzing and processing the images of self-organized patterns with Matlab 6.5, including "adumbrating the patterns", "adjusting the images", "locating the pattern units", "describing the brightness distribution", "Fourier transformation", and so on. Adjusting the images is to make some characteristics of the patterns more evidently. The method we use for adjusting the patterns is mapping the brightness of the original patterns to a new range of value. The spatial brightness distribution in the patterns can be obtained with the function "improfile", which computes the intensity values along a line or alone specified points in the image by using interpolation arithmetic. the types of the self-organized patterns can be determined by obtaining the spatial frequency spectrum of the patterns using Fourier transform. The location of the units is pinpointed by convolution operation between the unit digital picture and the pattern digital picture.

  17. Testing a polarimetric cloud imager aboard research vessel Polarstern: comparison of color-based and polarimetric cloud detection algorithms.

    PubMed

    Barta, Andrs; Horvth, Gbor; Horvth, kos; Egri, dm; Blah, Mikls; Barta, Pl; Bumke, Karl; Macke, Andreas

    2015-02-10

    Cloud cover estimation is an important part of routine meteorological observations. Cloudiness measurements are used in climate model evaluation, nowcasting solar radiation, parameterizing the fluctuations of sea surface insolation, and building energy transfer models of the atmosphere. Currently, the most widespread ground-based method to measure cloudiness is based on analyzing the unpolarized intensity and color distribution of the sky obtained by digital cameras. As a new approach, we propose that cloud detection can be aided by the additional use of skylight polarization measured by 180 field-of-view imaging polarimetry. In the fall of 2010, we tested such a novel polarimetric cloud detector aboard the research vessel Polarstern during expedition ANT-XXVII/1. One of our goals was to test the durability of the measurement hardware under the extreme conditions of a trans-Atlantic cruise. Here, we describe the instrument and compare the results of several different cloud detection algorithms, some conventional and some newly developed. We also discuss the weaknesses of our design and its possible improvements. The comparison with cloud detection algorithms developed for traditional nonpolarimetric full-sky imagers allowed us to evaluate the added value of polarimetric quantities. We found that (1)neural-network-based algorithms perform the best among the investigated schemes and (2)global information (the mean and variance of intensity), nonoptical information (e.g., sun-view geometry), and polarimetric information (e.g., the degree of polarization) improve the accuracy of cloud detection, albeit slightly. PMID:25968023

  18. Empirical orthogonal function analysis of cloud-containing coastal zone color scanner images of northeastern North American coastal waters

    NASA Technical Reports Server (NTRS)

    Eslinger, David L.; O'Brien, James J.; Iverson, Richard L.

    1989-01-01

    Empirical-orthogonal-function (EOF) analyses were carried out on 36 images of the Mid-Atlantic Bight and the Gulf of Maine, obtained by the CZCS aboard Nimbus 7 for the time period from February 28 through July 9, 1979, with the purpose of determining pigment concentrations in coastal waters. The EOF procedure was modified so as to include images with significant portions of data missing due to cloud obstruction, making it possible to estimate pigment values in areas beneath clouds. The results of image analyses explained observed variances in pigment concentrations and showed a south-to-north pattern corresponding to an April Mid-Atlantic Bight bloom and a June bloom over Nantucket Shoals and Platts Bank.

  19. 3D Aerosol-Cloud Radiative Interaction Observed in Collocated MODIS and ASTER Images of Cumulus Cloud Fields

    NASA Technical Reports Server (NTRS)

    Wen, Guoyong; Marshak, Alexander; Cahalan, Robert F.; Remer, Lorraine A.; Kleidman, Richard G.

    2007-01-01

    3D aerosol-cloud interaction is examined by analyzing two images containing cumulus clouds in biomass burning regions in Brazil. The research consists of two parts. The first part focuses on identifying 3D clo ud impacts on the reflectance of pixel selected for the MODIS aerosol retrieval based purely on observations. The second part of the resea rch combines the observations with radiative transfer computations to identify key parameters in 3D aerosol-cloud interaction. We found that 3D cloud-induced enhancement depends on optical properties of nearb y clouds as well as wavelength. The enhancement is too large to be ig nored. Associated biased error in 1D aerosol optical thickness retrie val ranges from 50% to 140% depending on wavelength and optical prope rties of nearby clouds as well as aerosol optical thickness. We caution the community to be prudent when applying 1D approximations in comp uting solar radiation in dear regions adjacent to clouds or when usin g traditional retrieved aerosol optical thickness in aerosol indirect effect research.

  20. Searching for pulsars using image pattern recognition

    SciTech Connect

    Zhu, W. W.; Berndsen, A.; Madsen, E. C.; Tan, M.; Stairs, I. H.; Brazier, A.; Lazarus, P.; Lynch, R.; Scholz, P.; Stovall, K.; Cohen, S.; Dartez, L. P.; Lunsford, G.; Martinez, J. G.; Mata, A.; Ransom, S. M.; Banaszak, S.; Biwer, C. M.; Flanigan, J.; Rohr, M. E-mail: berndsen@phas.ubc.ca; and others

    2014-02-01

    In the modern era of big data, many fields of astronomy are generating huge volumes of data, the analysis of which can sometimes be the limiting factor in research. Fortunately, computer scientists have developed powerful data-mining techniques that can be applied to various fields. In this paper, we present a novel artificial intelligence (AI) program that identifies pulsars from recent surveys by using image pattern recognition with deep neural nets—the PICS (Pulsar Image-based Classification System) AI. The AI mimics human experts and distinguishes pulsars from noise and interference by looking for patterns from candidate plots. Different from other pulsar selection programs that search for expected patterns, the PICS AI is taught the salient features of different pulsars from a set of human-labeled candidates through machine learning. The training candidates are collected from the Pulsar Arecibo L-band Feed Array (PALFA) survey. The information from each pulsar candidate is synthesized in four diagnostic plots, which consist of image data with up to thousands of pixels. The AI takes these data from each candidate as its input and uses thousands of such candidates to train its ∼9000 neurons. The deep neural networks in this AI system grant it superior ability to recognize various types of pulsars as well as their harmonic signals. The trained AI's performance has been validated with a large set of candidates from a different pulsar survey, the Green Bank North Celestial Cap survey. In this completely independent test, the PICS ranked 264 out of 277 pulsar-related candidates, including all 56 previously known pulsars and 208 of their harmonics, in the top 961 (1%) of 90,008 test candidates, missing only 13 harmonics. The first non-pulsar candidate appears at rank 187, following 45 pulsars and 141 harmonics. In other words, 100% of the pulsars were ranked in the top 1% of all candidates, while 80% were ranked higher than any noise or interference. The performance of this system can be improved over time as more training data are accumulated. This AI system has been integrated into the PALFA survey pipeline and has discovered six new pulsars to date.

  1. Searching for Pulsars Using Image Pattern Recognition

    NASA Astrophysics Data System (ADS)

    Zhu, W. W.; Berndsen, A.; Madsen, E. C.; Tan, M.; Stairs, I. H.; Brazier, A.; Lazarus, P.; Lynch, R.; Scholz, P.; Stovall, K.; Ransom, S. M.; Banaszak, S.; Biwer, C. M.; Cohen, S.; Dartez, L. P.; Flanigan, J.; Lunsford, G.; Martinez, J. G.; Mata, A.; Rohr, M.; Walker, A.; Allen, B.; Bhat, N. D. R.; Bogdanov, S.; Camilo, F.; Chatterjee, S.; Cordes, J. M.; Crawford, F.; Deneva, J. S.; Desvignes, G.; Ferdman, R. D.; Freire, P. C. C.; Hessels, J. W. T.; Jenet, F. A.; Kaplan, D. L.; Kaspi, V. M.; Knispel, B.; Lee, K. J.; van Leeuwen, J.; Lyne, A. G.; McLaughlin, M. A.; Siemens, X.; Spitler, L. G.; Venkataraman, A.

    2014-02-01

    In the modern era of big data, many fields of astronomy are generating huge volumes of data, the analysis of which can sometimes be the limiting factor in research. Fortunately, computer scientists have developed powerful data-mining techniques that can be applied to various fields. In this paper, we present a novel artificial intelligence (AI) program that identifies pulsars from recent surveys by using image pattern recognition with deep neural nets—the PICS (Pulsar Image-based Classification System) AI. The AI mimics human experts and distinguishes pulsars from noise and interference by looking for patterns from candidate plots. Different from other pulsar selection programs that search for expected patterns, the PICS AI is taught the salient features of different pulsars from a set of human-labeled candidates through machine learning. The training candidates are collected from the Pulsar Arecibo L-band Feed Array (PALFA) survey. The information from each pulsar candidate is synthesized in four diagnostic plots, which consist of image data with up to thousands of pixels. The AI takes these data from each candidate as its input and uses thousands of such candidates to train its ~9000 neurons. The deep neural networks in this AI system grant it superior ability to recognize various types of pulsars as well as their harmonic signals. The trained AI's performance has been validated with a large set of candidates from a different pulsar survey, the Green Bank North Celestial Cap survey. In this completely independent test, the PICS ranked 264 out of 277 pulsar-related candidates, including all 56 previously known pulsars and 208 of their harmonics, in the top 961 (1%) of 90,008 test candidates, missing only 13 harmonics. The first non-pulsar candidate appears at rank 187, following 45 pulsars and 141 harmonics. In other words, 100% of the pulsars were ranked in the top 1% of all candidates, while 80% were ranked higher than any noise or interference. The performance of this system can be improved over time as more training data are accumulated. This AI system has been integrated into the PALFA survey pipeline and has discovered six new pulsars to date.

  2. Investigation of Vortex Clouds and Droplet Sizes in Heated Water Spray Patterns Generated by Axisymmetric Full Cone Nozzles

    PubMed Central

    Naz, M. Y.; Sulaiman, S. A.; Ariwahjoedi, B.; Ku Shaari, Ku Zilati

    2013-01-01

    The hot water sprays are an important part of many industrial processes, where the detailed knowledge of physical phenomena involved in jet transportation, interaction, secondary breakup, evaporation, and coalescence of droplets is important to reach more efficient processes. The objective of the work was to study the water spray jet breakup dynamics, vortex cloud formation, and droplet size distribution under varying temperature and load pressure. Using a high speed camera, the spray patterns generated by axisymmetric full cone nozzles were visualized as a function water temperature and load pressure. The image analysis confirmed that the spray cone angle and width do not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The formation and decay of semitorus like vortex clouds were also noticed in spray structures generated at near water boiling point temperature. For the nozzle with smallest orifice diameter (1.19?mm), these vortex clouds were very clear at 90C heating temperature and 1 bar water load pressure. In addition, the sauter mean diameter (SMD) of the spray droplets was also measured by using Phase Doppler Anemometry (PDA) at different locations downstream of the nozzle exit. It was noticed that SMD varies slightly w.r.t. position when measured at room temperature whereas at higher temperature values, it became almost constant at distance of 55?mm downstream of the nozzle exit. PMID:24307881

  3. A method of periodic pattern localization on document images

    NASA Astrophysics Data System (ADS)

    Chernov, Timofey S.; Nikolaev, Dmitry P.; Kliatskine, Vitali M.

    2015-12-01

    Periodic patterns often present on document images as holograms, watermarks or guilloche elements which are mostly used for fraud protection. Localization of such patterns lets an embedded OCR system to vary its settings depending on pattern presence in particular image regions and improves the precision of pattern removal to preserve as much useful data as possible. Many document images' noise detection and removal methods deal with unstructured noise or clutter on documents with simple background. In this paper we propose a method of periodic pattern localization on document images which uses discrete Fourier transform that works well on documents with complex background.

  4. An effective thin cloud removal procedure for visible remote sensing images

    NASA Astrophysics Data System (ADS)

    Shen, Huanfeng; Li, Huifang; Qian, Yan; Zhang, Liangpei; Yuan, Qiangqiang

    2014-10-01

    Clouds are obstructions for land-surface observation, which result in the regional information being blurred or even lost. Thin clouds are transparent, and images of regions covered by thin clouds contain information about both the atmosphere and the ground. Therefore, thin cloud removal is a challenging task as the ground information is easily affected when the thin cloud removal is performed. An efficient and effective thin cloud removal method is proposed for visible remote sensing images in this paper, with the aim being to remove the thin clouds and also restore the ground information. Since thin cloud is considered as low-frequency information, the proposed method is based on the classic homomorphic filter and is executed in the frequency domain. The optimal cut-off frequency for each channel is determined semi-automatically. In order to preserve the clear pixels and ensure the high fidelity of the result, cloudy pixels are detected and handled separately. As a particular kind of low-frequency information, cloud-free water surfaces are specially treated and corrected. Since only cloudy pixels are involved in the calculation, the method is highly efficient and is suited for large remote sensing scenes. Scenes including different land-cover types were selected to validate the proposed method, and a comparison analysis with other methods was also performed. The experimental results confirm that the proposed method is effective in correcting thin cloud contaminated images while preserving the true spectral information.

  5. Ghost imaging with non-negative exponential speckle patterns

    NASA Astrophysics Data System (ADS)

    Zhang, Er-Feng; Liu, Wei-Tao; Chen, Ping-Xing

    2015-08-01

    The speckle patterns with non-negative exponential statistics are generated through introducing an iterative algorithm: the Gerchberg-Saxton (GS) algorithm. Furthermore, ghost imaging (GI) with the non-negative exponential speckle patterns is investigated, and the effect of the non-negative exponential speckle patterns on the image quality is analyzed.

  6. OpenID connect as a security service in Cloud-based diagnostic imaging systems

    NASA Astrophysics Data System (ADS)

    Ma, Weina; Sartipi, Kamran; Sharghi, Hassan; Koff, David; Bak, Peter

    2015-03-01

    The evolution of cloud computing is driving the next generation of diagnostic imaging (DI) systems. Cloud-based DI systems are able to deliver better services to patients without constraining to their own physical facilities. However, privacy and security concerns have been consistently regarded as the major obstacle for adoption of cloud computing by healthcare domains. Furthermore, traditional computing models and interfaces employed by DI systems are not ready for accessing diagnostic images through mobile devices. RESTful is an ideal technology for provisioning both mobile services and cloud computing. OpenID Connect, combining OpenID and OAuth together, is an emerging REST-based federated identity solution. It is one of the most perspective open standards to potentially become the de-facto standard for securing cloud computing and mobile applications, which has ever been regarded as "Kerberos of Cloud". We introduce OpenID Connect as an identity and authentication service in cloud-based DI systems and propose enhancements that allow for incorporating this technology within distributed enterprise environment. The objective of this study is to offer solutions for secure radiology image sharing among DI-r (Diagnostic Imaging Repository) and heterogeneous PACS (Picture Archiving and Communication Systems) as well as mobile clients in the cloud ecosystem. Through using OpenID Connect as an open-source identity and authentication service, deploying DI-r and PACS to private or community clouds should obtain equivalent security level to traditional computing model.

  7. Cloud top structure of Venus revealed by Subaru/COMICS mid-infrared images

    NASA Astrophysics Data System (ADS)

    Sato, T. M.; Sagawa, H.; Kouyama, T.; Mitsuyama, K.; Satoh, T.; Ohtsuki, S.; Ueno, M.; Kasaba, Y.; Nakamura, M.; Imamura, T.

    2014-11-01

    We have investigated the cloud top structure of Venus by analyzing ground-based images taken at the mid-infrared wavelengths of 8.66 μm and 11.34 μm. Venus at a solar phase angle of ∼90°, with the morning terminator in view, was observed by the Cooled Mid-Infrared Camera and Spectrometer (COMICS), mounted on the 8.2-m Subaru Telescope, during the period October 25-29, 2007. The disk-averaged brightness temperatures for the observation period are ∼230 K and ∼238 K at 8.66 μm and 11.34 μm, respectively. The obtained images with good signal-to-noise ratio and with high spatial resolution (∼200 km at the sub-observer point) provide several important findings. First, we present observational evidence, for the first time, of the possibility that the westward rotation of the polar features (the hot polar spots and the surrounding cold collars) is synchronized between the northern and southern hemispheres. Second, after high-pass filtering, the images reveal that streaks and mottled and patchy patterns are distributed over the entire disk, with typical amplitudes of ∼0.5 K, and vary from day to day. The detected features, some of which are similar to those seen in past UV images, result from inhomogeneities of both the temperature and the cloud top altitude. Third, the equatorial center-to-limb variations of brightness temperatures have a systematic day-night asymmetry, except those on October 25, that the dayside brightness temperatures are higher than the nightside brightness temperatures by 0-4 K under the same viewing geometry. Such asymmetry would be caused by the propagation of the migrating semidiurnal tide. Finally, by applying the lapse rates deduced from previous studies, we demonstrate that the equatorial center-to-limb curves in the two spectral channels give access to two parameters: the cloud scale height H and the cloud top altitude zc. The acceptable models for data on October 25 are obtained at H = 2.4-4.3 km and zc = 66-69 km; this supports previous results determined from spacecraft observations.

  8. 3D cloud detection and tracking system for solar forecast using multiple sky imagers

    DOE PAGESBeta

    Peng, Zhenzhou; Yu, Dantong; Huang, Dong; Heiser, John; Yoo, Shinjae; Kalb, Paul

    2015-06-23

    We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together intomore » larger views, which are then used for solar forecasting. We examine the system’s ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.« less

  9. 3D cloud detection and tracking system for solar forecast using multiple sky imagers

    SciTech Connect

    Peng, Zhenzhou; Yu, Dantong; Huang, Dong; Heiser, John; Yoo, Shinjae; Kalb, Paul

    2015-06-23

    We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together into larger views, which are then used for solar forecasting. We examine the system’s ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.

  10. Prediction of optical communication link availability: real-time observation of cloud patterns using a ground-based thermal infrared camera

    NASA Astrophysics Data System (ADS)

    Bertin, Clément; Cros, Sylvain; Saint-Antonin, Laurent; Schmutz, Nicolas

    2015-10-01

    The growing demand for high-speed broadband communications with low orbital or geostationary satellites is a major challenge. Using an optical link at 1.55 μm is an advantageous solution which potentially can increase the satellite throughput by a factor 10. Nevertheless, cloud cover is an obstacle for this optical frequency. Such communication requires an innovative management system to optimize the optical link availability between a satellite and several Optical Ground Stations (OGS). The Saint-Exupery Technological Research Institute (France) leads the project ALBS (French acronym for BroadBand Satellite Access). This initiative involving small and medium enterprises, industrial groups and research institutions specialized in aeronautics and space industries, is currently developing various solutions to increase the telecommunication satellite bandwidth. This paper presents the development of a preliminary prediction system preventing the cloud blockage of an optical link between a satellite and a given OGS. An infrared thermal camera continuously observes (night and day) the sky vault. Cloud patterns are observed and classified several times a minute. The impact of the detected clouds on the optical beam (obstruction or not) is determined by the retrieval of the cloud optical depth at the wavelength of communication. This retrieval is based on realistic cloud-modelling on libRadtran. Then, using subsequent images, cloud speed and trajectory are estimated. Cloud blockage over an OGS can then be forecast up to 30 minutes ahead. With this information, the preparation of the new link between the satellite and another OGS under a clear sky can be prepared before the link breaks due to cloud blockage.

  11. Images of Hurricane Katrina (2005) below the cloud

    NASA Astrophysics Data System (ADS)

    Dunkerton, T. J.; Walter, B. A.; Perrie, W.; Long, D. G.; Zhang, J.; Black, P. G.; Rogers, R.

    2006-12-01

    A remarkable coincidence of two independent satellite images from Radarsat-1 synthetic aperture radar (SAR) and SeaWinds/QuikSCAT scatterometer, depicting the state of the sea surface, and HRD/NOAA aircraft reconnaissance including a Stepped Frequency Microwave Radiometer (SFMR), occurred in Hurricane Katrina near the time of its maximum intensity on August 28th, 2005. The satellite images were acquired within 6 seconds of each other near 2345 UTC. The eye, primary and secondary eyewalls, and outer rainbands were traversed by the aircraft during the time of image acquisition, and all of these features are visible on the images, both of which captured most of the storm area. Comparison of SAR and scatterometer images indicates good agreement in the level of backscatter pixel-by-pixel when SAR pixels (~50 m) are averaged to match scatterometer pixels (~2.5 km). Comparison with airborne SFMR also indicates good agreement when the aircraft data are rotated slightly in azimuth to account for advection by the tangential surface winds over a period of 0-6 minutes. Seven independent measurements of horizontal wind are available in this unique situation: one from each satellite image, the airborne radiometer, in situ flight-level data, dropsondes, fuselage radar (for feature tracking of precipitation features) and tail Doppler radar (a 3D wind field synthesized over ~1 hour). Comparison of surface and flight level data in the primary eyewall indicates an outward tilt of the axis of maximum winds with height similar to that seen in the Doppler composite structure obtained around this time. Surface winds appear stronger than flight-level winds in the primary eyewall but not in a secondary eyewall farther out.. Tangential wind maxima are associated with both eyewalls -- each a ring of enhanced precipitation -- and both are superposed on a radial profile of rather strong winds, suggesting that significant microwave backscatter should be expected throughout the inner core, as observed. Nevertheless, the imprint of eye and eyewalls on the sea surface is clearly visible in the satellite backscatter images and in surface winds derived from their respective retrieval algorithms. Our coincidence of independent wind measurements provides an unprecedented opportunity for algorithm validation in an extreme wind/rainfall environment and to assess the impacts, if any, of cloud liquid water and raindrops on beam attenuation in the C and Ku bands used, respectively, by the SAR and scatterometer. A few suspiciously dark features in an outer rainband are detected in both satellite images, and an attempt is made to collocate with spots of maximum precipitation in a sequence of fuselage radar images in order to address this issue. Similar features are sometimes seen in SAR images of other hurricanes, suggesting small pockets or "seams" of relative calm. Comments are made on the utility of SAR imagery for ocean swell and sea spray in the hurricane inner-core environment, and for depiction of convective downdrafts in the outer bands.

  12. Geographical correlation of TV and IR images obtained from weather satellites. [cloud cover photography

    NASA Technical Reports Server (NTRS)

    Ziman, Y. L.; Nepoklonov, B. N.; Rodionov, B. N.

    1974-01-01

    The requirements on the accuracy of geographical correlation of TV and IR cloud cover images are determined by the objective of the analysis of the weather information contained in these images. In the operational analysis case, the correlation accuracy need not be high. Errors of several tens of kilometers in determining the location of the cloud formation contours are considered acceptable in this case. Such correlation must be provided in real image reception time. Scientific studies require accurate correlation of the cloud formation contours. The errors in determining their position should be commensurate with the imaging system resolution. The geometric aspects of developing methods and equipment for geographical correlation of television and infrared images of cloud cover taken from Meteor satellites are discussed.

  13. Accuracy assessment of building point clouds automatically generated from iphone images

    NASA Astrophysics Data System (ADS)

    Sirmacek, B.; Lindenbergh, R.

    2014-06-01

    Low-cost sensor generated 3D models can be useful for quick 3D urban model updating, yet the quality of the models is questionable. In this article, we evaluate the reliability of an automatic point cloud generation method using multi-view iPhone images or an iPhone video file as an input. We register such automatically generated point cloud on a TLS point cloud of the same object to discuss accuracy, advantages and limitations of the iPhone generated point clouds. For the chosen example showcase, we have classified 1.23% of the iPhone point cloud points as outliers, and calculated the mean of the point to point distances to the TLS point cloud as 0.11 m. Since a TLS point cloud might also include measurement errors and noise, we computed local noise values for the point clouds from both sources. Mean (?) and standard deviation (?) of roughness histograms are calculated as (?1 = 0.44 m., ?1 = 0.071 m.) and (?2 = 0.025 m., ?2 = 0.037 m.) for the iPhone and TLS point clouds respectively. Our experimental results indicate possible usage of the proposed automatic 3D model generation framework for 3D urban map updating, fusion and detail enhancing, quick and real-time change detection purposes. However, further insights should be obtained first on the circumstances that are needed to guarantee a successful point cloud generation from smartphone images.

  14. Improving Assimilation of Microwave Radiances in Cloudy Situations with Collocated High Resolution Imager Cloud Mask

    NASA Astrophysics Data System (ADS)

    Han, H.; Li, J.; Goldberg, M.; Wang, P.; Li, Z.

    2014-12-01

    Tropical cyclones (TCs) accompanied with heavy rainfall and strong wind are high impact weather systems, often causing extensive property damage and even fatalities when landed. Better prediction of TCs can lead to substantial reduction of social and economic damage; there are growing interests in the enhanced satellite data assimilation for improving TC forecasts. Accurate cloud detection is one of the most important factors in satellite data assimilation due to the uncertainties of cloud properties and their impacts on satellite observed radiances. To enhance the accuracy of cloud detection and improve the TC forecasting, microwave measurements are collocated with high spatial resolution imager cloud mask. The collocated advanced microwave sounder measurements are assimilated for the hurricane Sandy (2012) and typhoon Haiyan (2013) forecasting using the Weather Research and Forecasting (WRF) model and the 3DVAR-based Gridpoint Statistical Interpolation (GSI) data assimilation system. Experiments will be carried out to determine a cloud cover threshold to distinguish between cloud affected and cloud unaffected footprints. The results indicate that the use of the high spatial resolution imager cloud mask can improve the accuracy of TC forecasts by eliminating cloud contaminated pixels. The methodology used in this study is applicable to advanced microwave sounders and high spatial resolution imagers, such as ATMS/VIIRS onboard NPP and JPSS, and IASI/AVHRR from Metop, for the improved TC track and intensity forecasts.

  15. Weekly Cycle of Lightning and Associated Patterns of Rainfall, Cloud, and Aerosols over Korea and Adjacent Oceans during Boreal Summer

    NASA Technical Reports Server (NTRS)

    Kim, Ji-In; Kim, Kyu-Myong

    2011-01-01

    In this study, we analyze the weekly cycle of lightning over Korea and adjacent oceans and associated variations of aerosols, clouds, precipitation, and atmospheric circulations, using aerosol optical depth (AOD) from the NASA Moderate resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging SpectroRadiometer (MISR), cloud properties from MODIS, precipitation and storm height from Tropical Rainfall Measuring Mission (TRMM) satellite, and lightning data from the Korean Lightning Detection Network (KLDN) during 9-year from 2002 to 2010. Lightning data was divided into three approximately equal areas, land area of Korea, and two adjacent oceans, Yellow Sea and South Sea. Preliminary results show that the number of lightning increases during the middle of the week over Yellow Sea. AOD data also shows moderately significant midweek increase at about the same time as lightning peaks. These results are consistent with the recent studies showing the invigoration of storms with more ice hydrometeors by aerosols, and subsequently wash out of aerosols by rainfall. Frequency of lightning strokes tend to peak at weekend in land area and over South Sea, indicating local weekly anomalous circulation between land and adjacent ocean. On the other hand, lightning frequency over Yellow Sea appears to have very strong weekly cycle with midweek peak on around Wednesday. It is speculated that the midweek peak of lightning over Yellow Sea was related with aerosol transport from adjacent land area. AOD data also suggests midweek peak over Yellow Sea, however, the weekly cycle of AOD was not statistically significant. Changes in weekly cycle of lightning from pre-monsoon to monsoon season, as well as associated clouds and circulation patterns are also discussed.

  16. Weekly cycle of lightning and associated patterns of rainfall, cloud, and aerosols over Korea and adjacent oceans during boreal summer

    NASA Astrophysics Data System (ADS)

    Kim, J.; Kim, K.

    2011-12-01

    In this study, we analyze the weekly cycle of lightning over Korea and adjacent oceans and associated variations of aerosols, clouds, precipitation, and atmospheric circulations, using aerosol optical depth (AOD) from the NASA Moderate resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging SpectroRadiometer (MISR), cloud properties from MODIS, precipitation and storm height from Tropical Rainfall Measuring Mission (TRMM) satellite, and lightning data from the Korean Lightning Detection Network (KLDN) during 9-year from 2002 to 2010. Lightning data was divided into three approximately equal areas, land area of Korea, and two adjacent oceans, Yellow Sea and South Sea. Preliminary results show that the number of lightning increases during the middle of the week over land area. AOD data also shows moderately significant midweek increase at about the same time as lightning peaks. These results are consistent with the recent studies showing the invigoration of storms with more ice hydrometeors by aerosols, and subsequently wash out of aerosols by rainfall. Frequency of lightning strokes tend to peak at weekend in coastal area and over South Sea, indicating local weekly anomalous circulation between land and adjacent ocean. On the other hand, lightning frequency over Yellow Sea appears to have very strong weekly cycle with midweek peak on around Wednesday. It is speculated that the midweek peak of lightning over Yellow Sea was related with aerosol transport from adjacent land area. AOD data also suggests midweek peak over Yellow Sea, however, the weekly cycle of AOD was not statistically significant. Changes in weekly cycle of lightning from pre-monsoon to monsoon season, as well as associated clouds and circulation patterns are also discussed.

  17. A Medical Image Backup Architecture Based on a NoSQL Database and Cloud Computing Services.

    PubMed

    Santos Simões de Almeida, Luan Henrique; Costa Oliveira, Marcelo

    2015-01-01

    The use of digital systems for storing medical images generates a huge volume of data. Digital images are commonly stored and managed on a Picture Archiving and Communication System (PACS), under the DICOM standard. However, PACS is limited because it is strongly dependent on the server's physical space. Alternatively, Cloud Computing arises as an extensive, low cost, and reconfigurable resource. However, medical images contain patient information that can not be made available in a public cloud. Therefore, a mechanism to anonymize these images is needed. This poster presents a solution for this issue by taking digital images from PACS, converting the information contained in each image file to a NoSQL database, and using cloud computing to store digital images. PMID:26262231

  18. Analysis of dust cloud combustion using FAST Infrared Imaging

    NASA Astrophysics Data System (ADS)

    Marcotte, Frederick; Farley, Vincent; Savary, Simon

    2013-05-01

    Dust cloud combustion is unfortunately at risk in many working environments, jeopardizing several workers. The heat and shock waves resulting from the flame propagation into the dust cloud are harmful and lead to major endangerment or casualties. More precisely, dust cloud (small particles) explosions are even more malicious since they often result from ordinary materials such as coal, flour or pollen. Also, many metal powdered (such as aluminum oxide and magnesium) can form dangerous dust cloud when they are in suspensions in air. The understanding of this particular type of combustion is critical for the preventive care of sites and workers afflicted to such conditions. This paper presents the results of a dynamic flow analysis of metal particles combustion in a dust cloud. The ignition points, the flow rate as well as the propagation direction of the flow have been characterized using fast infrared imagery.

  19. Deep infrared images of the Small Magellanic Cloud and comparison with the distribution of ultraviolet emission

    NASA Technical Reports Server (NTRS)

    Okumura, K.; Viallefond, F.; Viton, M.; Rice, W.

    1992-01-01

    Deep infrared images of the Small Magellanic Cloud have been produced and compared to an ultraviolet image at an angular resolution of 8 min. There is a strong correlation between the far infrared and the ultraviolet emission but the dispersion in this correlation is unrelated to infrared colors. Comparing with the results for the nearby spiral M33 at different radial distances, it is suggested that the population of dust grains in the Small Magellanic Cloud has very different properties.

  20. Satellite retrieval of convective cloud base temperature based on the NPP/VIIRS Imager

    NASA Astrophysics Data System (ADS)

    Zhu, Yannian; Rosenfeld, Daniel; Yu, Xing; Liu, Guihua; Dai, Jin; Xu, Xiaohong

    2014-02-01

    The advent of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-Orbiting Partnership (NPP) satellite provided a quantum jump in the satellite capabilities of retrieving cloud properties, because it nearly tripled the resolution in the thermal channels (375 m). This allowed us to develop a methodology for retrieving convective cloud base temperature (Tb) and validate it over the Atmospheric System Research Southern Great Plains site for the satellite early afternoon overpass time. The standard error of the Tb retrieval was only 1.1C. The knowledge of Tb allows the calculation of cloud base height and the depth of the boundary layer, as well as the boundary layer water vapor mixing ratio with an accuracy of about 10%. The feasibility of retrieving cloud base temperature and height is an essential component that is required for retrieving cloud condensation nuclei (CCN) from satellites by using convective clouds as natural CCN chambers.

  1. A novel approach for the extraction of cloud motion vectors using airglow imager measurements

    NASA Astrophysics Data System (ADS)

    Satheesh Kumar, S.; Narayana Rao, T.; Taori, A.

    2015-09-01

    The paper explores the possibility of implementing an advanced photogrammetric technique, generally employed for satellite measurements, on airglow imager, a ground-based remote sensing instrument primarily used for upper atmospheric studies, measurements of clouds for the extraction of cloud motion vectors (CMVs). The major steps involved in the algorithm remain the same, including image processing for better visualization of target elements and noise removal, identification of target cloud, setting a proper search window for target cloud tracking, estimation of cloud height, and employing 2-D cross-correlation to estimate the CMVs. Nevertheless, the implementation strategy at each step differs from that of satellite, mainly to suit airglow imager measurements. For instance, climatology of horizontal winds at the measured site has been used to fix the search window for target cloud tracking. The cloud height is estimated very accurately, as required by the algorithm, using simultaneous collocated lidar measurements. High-resolution, both in space and time (4 min), cloud imageries are employed to minimize the errors in retrieved CMVs. The derived winds are evaluated against MST radar-derived winds by considering it as a reference. A very good correspondence is seen between these two wind measurements, both showing similar wind variation. The agreement is also found to be good in both the zonal and meridional wind velocities with RMSEs < 2.4 m s-1. Finally, the strengths and limitations of the algorithm are discussed, with possible solutions, wherever required.

  2. Advanced infrared sounder subpixel cloud detection with imagers and its impact on radiance assimilation in NWP

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Li, Jun; Li, Jinlong; Li, Zhenglong; Schmit, Timothy J.; Bai, Wenguang

    2014-03-01

    Accurate cloud detection is very important for infrared (IR) radiance assimilation; improved cloud detection could reduce cloud contamination and hence improve the assimilation. Although operational numerical weather prediction (NWP) centers are using IR sounder radiance data for cloud detection, collocated high spatial resolution imager data could help sounder subpixel cloud detection and characterization. IR sounder radiances with improved cloud detection using Atmospheric Infrared Sounder (AIRS)/Moderate Resolution Imaging Spectroradiometer (MODIS) were assimilated for Hurricane Sandy (2012). Forecast experiments were run with Weather Research and Forecasting (WRF) as the forecast model and the Three-Dimensional Variational Assimilation (3DVAR)-based Gridpoint Statistical Interpolation (GSI) as the analysis system. Results indicate that forecasts of both hurricane track and intensity are substantially improved when the collocated high spatial resolution MODIS cloud mask is used for AIRS subpixel cloud detection for assimilating radiances. This methodology can be applied to process Crosstrack Infrared Sounder (CRIS)/Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi-NPOESS Preparatory Project (NPP)/Joint Polar Satellite System (JPSS) and Infrared Atmospheric Sounding Interferometer (IASI)/Advanced Very High Resolution Radiometer (AVHRR) onboard the Metop series for improved radiance assimilation in NWP.

  3. Pattern recognition in hyperspectral persistent imaging

    NASA Astrophysics Data System (ADS)

    Rosario, Dalton; Romano, Joao; Borel, Christoph

    2015-05-01

    We give updates on a persistent imaging experiment dataset, being considered for public release in a foreseeable future, and present additional observations analyzing a subset of the dataset. The experiment is a long-term collaborative effort among the Army Research Laboratory, Army Armament RDEC, and Air Force Institute of Technology that focuses on the collection and exploitation of longwave infrared (LWIR) hyperspectral imagery. We emphasize the inherent challenges associated with using remotely sensed LWIR hyperspectral imagery for material recognition, and show that this data type violates key data assumptions conventionally used in the scientific community to develop detection/ID algorithms, i.e., normality, independence, identical distribution. We treat LWIR hyperspectral imagery as Longitudinal Data and aim at proposing a more realistic framework for material recognition as a function of spectral evolution through time, and discuss limitations. The defining characteristic of a longitudinal study is that objects are measured repeatedly through time and, as a result, data are dependent. This is in contrast to cross-sectional studies in which the outcomes of a specific event are observed by randomly sampling from a large population of relevant objects in which data are assumed independent. Researchers in the remote sensing community generally assume the problem of object recognition to be cross-sectional. But through a longitudinal analysis of a fixed site with multiple material types, we quantify and argue that, as data evolve through a full diurnal cycle, pattern recognition problems are longitudinal in nature and that by applying this knowledge may lead to better algorithms.

  4. Registration of vehicle based panoramic image and LiDAR point cloud

    NASA Astrophysics Data System (ADS)

    Chen, Changjun; Cao, Liang; Xie, Hong; Zhuo, Xiangyu

    2013-10-01

    Higher quality surface information would be got when data from optical images and LiDAR were integrated, owing to the fact that optical images and LiDAR point cloud have unique characteristics that make them preferable in many applications. While most previous works focus on registration of pinhole perspective cameras to 2D or 3D LiDAR data. In this paper, a method for the registration of vehicle based panoramic image and LiDAR point cloud is proposed. Using the translation among panoramic image, single CCD image, laser scanner and Position and Orientation System (POS) along with the GPS/IMU data, precise co-registration between the panoramic image and the LiDAR point cloud in the world system is achieved. Results are presented under a real world data set collected by a new developed Mobile Mapping System (MMS) integrated with a high resolution panoramic camera, two laser scanners and a POS.

  5. A novel computer-generated hologram (CGH) achieved scheme using point cloud based on integral imaging

    NASA Astrophysics Data System (ADS)

    Li, Wei-Na; Piao, Mei-Lan; Jeon, Seok-Hee; Jeong, Jong-Rae; Kim, Nam

    2015-03-01

    We proposed a novel scheme to achieve a computer-generated hologram (CGH). The CGH is generated from a point cloud that is transformed by a mapping relationship of a series of sub-images. The sub-images are converted from elemental images captured by integral imaging pickup system. A more continues depth map can be obtained and a clearer display of the 3D scene can be presented. Moreover, the inherent drawback pseudoscopic problem of integral imaging can also be overcome.

  6. The identification of cloud types in LANDSAT MSS images. [Great Britain

    NASA Technical Reports Server (NTRS)

    Barrett, E. C. (Principal Investigator); Grant, C. K.

    1976-01-01

    The author has identified the following significant results. Five general families of clouds were identified: cumulonimbiform, cumuliform, stratiform, stratocumuliform, and cirriform. Four members of this five-fold primary division of clouds were further divided into a number of subgroups. The MSS observed and recorded earth radiation in four different wavebands. Two of these bands (4 and 5) image in the visible portion of the electromagnetic spectrum, while the others (6 and 7) image the short wave portion, or just into the infrared. The main differences between the appearances of clouds in the four wavebands are related to the background brightness of land and sea surfaces.

  7. Space radar image of Western Pacific rain clouds

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This radar image shows the ocean surface in a portion of the Western Pacific Ocean. Scientists are using images like this to study the occurrence, distribution and activity of tropical rain squalls and to understand the exchange of heat between the atmosphere and ocean and the upper layer mixing in the tropical oceans, which are critical factors for understanding the driving forces which produce the El Nino phenomenon. The white, curved area at the top of the image is a portion of the Ontong Java Atoll, part of the Solomon Islands group. The yellowish green area near the bottom of the image is an intense rain cell. This image is centered near 5.5 degrees South latitude and 159.5 degrees East longitude. The area shown is 50 kilometers by 21 kilometers (31 miles by 13 miles). This image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 13th orbit on April 10, 1994. The colors in the image are assigned to different frequencies and polarizations of the SIR-C radar as follows: Red is C-band horizontally transmitted and received; green is L-band horizontally transmitted and vertically received and blue is L-band horizontally transmitted and received. The large rain cell is about 15 kilometers by 15 kilometers (9 miles by 9 miles) and contains two dark regions, one circular and one rectangular, inside it. Two smaller reddish cells are visible closer to the atoll. The red areas may be caused by reflection from ice particles in the colder, upper portion of the storm cell and not from the ocean surface at all. This provides direct evidence that it is raining within this storm cell, valuable information which is usually very difficult to measure over more remote regions of the ocean away from coastal-based weather systems. The dark holes in the middle of the cell are thought to be areas of very heavy rainfall which actually smooth out the ocean surface and result in lower radar returns. The surrounding ocean is blue to green plus black. Winds and currents cause the ocean surface to be rough and those variations on the surface affect how the radar signals bounce off the surface. The bright areas on the image correspond to areas where the wind speed is high. The highest winds are seen as the yellow-green region of the large rain cell. The lowest winds are seen inside the atoll as dark areas. Outside the rain cell, the winds are moderately low, which is indicated by the puff-like, blue patterns surrounding the cell and extending into the atoll. The long, thin, dark lines extending across the ocean are surface currents. Here the currents are likely accumulating natural oils caused by small marine biological organisms. The oils cause the small, wind-generated waves to be reduced in size or damped which produces a smooth, dark zone on the radar image.

  8. Cloud motions on Neptune from Voyager 2 images

    NASA Technical Reports Server (NTRS)

    Limaye, S. S.; Sromovsky, L. A.; Suomi, V. E.

    1992-01-01

    The puzzle presented by Neptune's circulation is evidenced by its wide spectrum of wind speeds and differences between the drift rate of its longest lived features and its finer scale cloud forms, unlike Jupiter or Saturn. Neptune's clouds appear dynamic and show strong evidence of atmospheric waves, making cloud motion measurements somewhat difficult and requiring some departures from the methods which have been traditionally used to determine atmospheric circulations. New measurements of cloud motions of Neptune that confirm the general characteristics reported by Smith et al. (1989) are presented below. Besides greater number of measurements from a higher time resolution data set, the new results reveal the shape of the westerly jet at 72 deg S latitude.

  9. Planar Constraints for AN Improved Uav-Image Dense Point Cloud Generation

    NASA Astrophysics Data System (ADS)

    He, F.; Habib, A.; Al-Rawabdeh, A.

    2015-08-01

    In this paper, we proposed a new refinement procedure for the semi-global dense image matching. In order to remove outliers and improve the disparity image derived from the semi-global algorithm, both the local smoothness constraint and point cloud segments are utilized. Compared with current refinement technique, which usually assumes the correspondences between planar surfaces and 2D image segments, our proposed approach can effectively deal with object with both planar and curved surfaces. Meanwhile, since 3D point clouds contain more precise geometric information regarding to the reconstructed objects, the planar surfaces identified in our approach can be more accurate. In order to illustrate the feasibility of our approach, several experimental tests are conducted on both Middlebury test and real UAV-image datasets. The results demonstrate that our approach has a good performance on improving the quality of the derived dense image-based point cloud.

  10. The computation of cloud base height from paired whole-sky imaging cameras

    SciTech Connect

    Allmen, M.C.; Kegelmeyer, W.P. Jr.

    1994-03-01

    A major goal for global change studies is to improve the accuracy of general circulation models (GCMs) capable of predicting the timing and magnitude of greenhouse gas-induced global warming. Research has shown that cloud radiative feedback is the single most important effect determining the magnitude of possible climate responses to human activity. Of particular value to reducing the uncertainties associated with cloud-radiation interactions is the measurement of cloud base height (CBH), both because it is a dominant factor in determining the infrared radiative properties of clouds with respect to the earth`s surface and lower atmosphere and because CBHs are essential to measuring cloud cover fraction. We have developed a novel approach to the extraction of cloud base height from pairs of whole sky imaging (WSI) cameras. The core problem is to spatially register cloud fields from widely separated WSI cameras; this complete, triangulation provides the CBH measurements. The wide camera separation (necessary to cover the desired observation area) and the self-similarity of clouds defeats all standard matching algorithms when applied to static views of the sky. To address this, our approach is based on optical flow methods that exploit the fact that modern WSIs provide sequences of images. We will describe the algorithm and present its performance as evaluated both on real data validated by ceilometer measurements and on a variety of simulated cases.

  11. Cloud Remote Sensing with Sideways-Looks : Theory and First Results Using Multispectral Thermal Imager Data

    SciTech Connect

    Davis, A. B.

    2002-01-01

    In operational remote sensing, the implicit model for cloud geometry is a homogeneous plane-parallel slab of infinite horizontal extent. Each pixel is indeed processed as if it exchanged no radiant energy whatsoever with its neighbors. The shortcomings of this conceptual model have been well documented in the specialized literature but rarely mitigated. The worst-case scenario is probably high-resolution imagery where dense isolated clouds are visible, often both bright (reflective) and dark (transmissive) sides being apparent from the same satellite viewing angle: the low transmitted radiance could conceivably be interpreted in plane-parallel theory as no cloud at all. An alternative to the plane-parallel cloud model is introduced here that has the same appeal of being analytically tractable, at least in the diffusion limit: the spherical cloud. This new geometrical paradigm is applied to radiances from cumulus clouds captured by DOE's Multispectral Thermal Imager (MTI). Estimates of isolated cloud opacities are a necessary first step in correcting radiances from surface targets that are visible in the midst of a broken-cloud field. This type of advanced atmospheric correction is badly needed in remote sensing applications such as nonproliferation detection were waiting for a cloud-free look in the indefinite future is not a viable option.

  12. Time evolution of surface chlorophyll patterns from cross-spectrum analysis of satellite color images

    NASA Technical Reports Server (NTRS)

    Denman, Kenneth L.; Abbott, Mark R.

    1988-01-01

    The rate of decorrelation of surface chlorophyll patterns as a function of the time separation between pairs of images was determined from two sequences of CZCS images of the Pacific Ocean area adjacent to Vancouver Island, Canada; cloud-free subareas were selected that were common to several images separated in time by 1-17 days. Image pairs were subjected to two-dimensional autospectrum and cross-spectrum analysis in an array processor, and squared coherence estimates found for several wave bands were plotted against time separation, in analogy with a time-lagged cross correlation function. It was found that, for wavelengths of 50-150 km, significant coherence was lost after 7-10 days, while for wavelengths of 25-50 km, significant coherence was lost after only 5-7 days. In both cases, offshore regions maintained coherence longer than coastal regions.

  13. Identification of damage in buildings based on gaps in 3D point clouds from very high resolution oblique airborne images

    NASA Astrophysics Data System (ADS)

    Vetrivel, Anand; Gerke, Markus; Kerle, Norman; Vosselman, George

    2015-07-01

    Point clouds generated from airborne oblique images have become a suitable source for detailed building damage assessment after a disaster event, since they provide the essential geometric and radiometric features of both roof and façades of the building. However, they often contain gaps that result either from physical damage or from a range of image artefacts or data acquisition conditions. A clear understanding of those reasons, and accurate classification of gap-type, are critical for 3D geometry-based damage assessment. In this study, a methodology was developed to delineate buildings from a point cloud and classify the present gaps. The building delineation process was carried out by identifying and merging the roof segments of single buildings from the pre-segmented 3D point cloud. This approach detected 96% of the buildings from a point cloud generated using airborne oblique images. The gap detection and classification methods were tested using two other data sets obtained with Unmanned Aerial Vehicle (UAV) images with a ground resolution of around 1-2 cm. The methods detected all significant gaps and correctly identified the gaps due to damage. The gaps due to damage were identified based on the surrounding damage pattern, applying Gabor wavelets and a histogram of gradient orientation features. Two learning algorithms - SVM and Random Forests were tested for mapping the damaged regions based on radiometric descriptors. The learning model based on Gabor features with Random Forests performed best, identifying 95% of the damaged regions. The generalization performance of the supervised model, however, was less successful: quality measures decreased by around 15-30%.

  14. Image processing methods in two and three dimensions used to animate remotely sensed data. [cloud cover

    NASA Technical Reports Server (NTRS)

    Hussey, K. J.; Hall, J. R.; Mortensen, R. A.

    1986-01-01

    Image processing methods and software used to animate nonimaging remotely sensed data on cloud cover are described. Three FORTRAN programs were written in the VICAR2/TAE image processing domain to perform 3D perspective rendering, to interactively select parameters controlling the projection, and to interpolate parameter sets for animation images between key frames. Operation of the 3D programs and transferring the images to film is automated using executive control language and custom hardware to link the computer and camera.

  15. Optical Imaging of Flow Pattern and Phantom

    NASA Technical Reports Server (NTRS)

    Galland, Pierre A.; Liang, X.; Wang, L.; Ho, P. P.; Alfano, R. R.; Breisacher, K.

    1999-01-01

    Time-resolved optical imaging technique has been used to image the spatial distribution of small droplets and jet sprays in a highly scattering environment. The snake and ballistic components of the transmitted pulse are less scattered, and contain direct information about the sample to facilitate image formation as opposed to the diffusive components which are due to multiple collisions as a light pulse propagates through a scattering medium. In a time-gated imaging scheme, these early-arriving, image-bearing components of the incident pulse are selected by opening a gate for an ultrashort period of time and a shadowgram image is detected. Using a single shot cooled CCD camera system, the formation of water droplets is monitored as a function of time. Picosecond time-gated image of drop in scattering cells, spray droplets as a function of let speed and gas pressure, and model calcification samples consisted of calcium carbonate particles of irregular shapes ranging in size from 0. 1 to 1.5 mm affixed to a microscope slide have been measured. Formation produced by an impinging jet will be further monitored using a CCD with 1 kHz framing illuminated with pulsed light. The desired image resolution of the fuel droplets is on the 20 pm scale using early light through a highly scattering medium. A 10(exp -6)m displacement from a jet spray with a flow speed of 100 m/sec introduced by the ns grating pulse used in the imaging is negligible. Early ballistic/snake light imaging offers nondestructive and noninvasive method to observe the spatial distribution of hidden objects inside a highly scattering environment for space, biomedical, and materials applications. In this paper, the techniques we will present are time-resolved K-F transillumination imaging and time-gated scattered light imaging. With a large dynamic range and high resolution, time-gated early light imaging has the potential for improving rocket/aircraft design by determining jets shape and particle sizes. Refinements to these techniques may enable drop size measurements in the highly scattering, optically dense region of multi-element rocket injectors. These types of measurements should greatly enhance the design of stable, and higher performing rocket engines.

  16. Towards a more cloud-friendly medical imaging applications architecture: a modest proposal.

    PubMed

    Langer, Steve G; Persons, Ken; Erickson, Bradley J; Blezek, Dan

    2013-02-01

    Recent information technology literature, in general, and radiology trade journals, in particular, are rife with allusions to the "cloud" suggesting that moving one's compute and storage assets into someone else's data center magically solves cost, performance, and elasticity problems. More likely, one is only trading one set of problems for another, including greater latency (aka slower turnaround times) since the image data must now leave the local area network and travel longer paths via encrypted tunnels. To offset this, an imaging system design is needed that reduces the number of high-latency image transmissions, yet can still leverage cloud strengths. This work explores the requirements for such a design. PMID:23135215

  17. Investigation into Cloud Computing for More Robust Automated Bulk Image Geoprocessing

    NASA Technical Reports Server (NTRS)

    Brown, Richard B.; Smoot, James C.; Underwood, Lauren; Armstrong, C. Duane

    2012-01-01

    Geospatial resource assessments frequently require timely geospatial data processing that involves large multivariate remote sensing data sets. In particular, for disasters, response requires rapid access to large data volumes, substantial storage space and high performance processing capability. The processing and distribution of this data into usable information products requires a processing pipeline that can efficiently manage the required storage, computing utilities, and data handling requirements. In recent years, with the availability of cloud computing technology, cloud processing platforms have made available a powerful new computing infrastructure resource that can meet this need. To assess the utility of this resource, this project investigates cloud computing platforms for bulk, automated geoprocessing capabilities with respect to data handling and application development requirements. This presentation is of work being conducted by Applied Sciences Program Office at NASA-Stennis Space Center. A prototypical set of image manipulation and transformation processes that incorporate sample Unmanned Airborne System data were developed to create value-added products and tested for implementation on the "cloud". This project outlines the steps involved in creating and testing of open source software developed process code on a local prototype platform, and then transitioning this code with associated environment requirements into an analogous, but memory and processor enhanced cloud platform. A data processing cloud was used to store both standard digital camera panchromatic and multi-band image data, which were subsequently subjected to standard image processing functions such as NDVI (Normalized Difference Vegetation Index), NDMI (Normalized Difference Moisture Index), band stacking, reprojection, and other similar type data processes. Cloud infrastructure service providers were evaluated by taking these locally tested processing functions, and then applying them to a given cloud-enabled infrastructure to assesses and compare environment setup options and enabled technologies. This project reviews findings that were observed when cloud platforms were evaluated for bulk geoprocessing capabilities based on data handling and application development requirements.

  18. Typhoon center location algorithm based on fractal feature and gradient of infrared satellite cloud image

    NASA Astrophysics Data System (ADS)

    Zhang, Changjiang; Chen, Yuan; Lu, Juan

    2014-11-01

    An efficient algorithm for typhoon center location is proposed using fractal feature and gradient of infrared satellite cloud image. The centers are generally located in this region for a typhoon except the latter disappearing typhoon. The characteristics of dense cloud region are smoother texture and higher gray values than those of marginal clouds. So the window analysis method is used to select an appropriate cloud region. The window whose difference value between the sum of the gray-gradient co-occurrence matrix and fractal dimension is the biggest is chosen as the dense cloud region. The temperature gradient of the region, which is near typhoon center except typhoon eye, is small. Thus the gradient information is strengthened and is calculated by canny operator. Then we use a window to traverse the dense cloud region. If there is a closed curve, the region of curve is considered as the typhoon center region. Otherwise, the region in which there is the most texture intersection and the biggest density is considered as the typhoon center region. Finally, the geometric center of the center region is determined as the typhoon center location. The effectiveness is test by Chinese FY-2C stationary satellite cloud image. And the result is compared with the typhoon center location in the "tropical cyclone yearbook" which was compiled by Shanghai typhoon institute of China meteorological administration. Experimental results show that the high location accuracy can be obtained.

  19. A Cloud-Based Infrastructure for Feedback-Driven Training and Image Recognition.

    PubMed

    Abedini, Mani; von Cavallar, Stefan; Chakravorty, Rajib; Davis, Matthew; Garnavi, Rahil

    2015-01-01

    Advanced techniques in machine learning combined with scalable "cloud" computing infrastructure are driving the creation of new and innovative health diagnostic applications. We describe a service and application for performing image training and recognition, tailored to dermatology and melanoma identification. The system implements new machine learning approaches to provide a feedback-driven training loop. This training sequence enhances classification performance by incrementally retraining the classifier model from expert responses. To easily provide this application and associated web service to clinical practices, we also describe a scalable cloud infrastructure, deployable in public cloud infrastructure and private, on-premise systems. PMID:26262140

  20. Diurnal, Seasonal, and Interannual Variations of Cloud Properties Derived for CERES From Imager Data

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Young, David F.; Sun-Mack, Sunny; Trepte, Qing Z.; Chen, Yan; Brown, Richard R.; Gibson, Sharon; Heck, Patrick W.

    2004-01-01

    Simultaneous measurement of the radiation and cloud fields on a global basis is a key component in the effort to understand and model the interaction between clouds and radiation at the top of the atmosphere, at the surface, and within the atmosphere. The NASA Clouds and Earth s Radiant Energy System (CERES) Project, begun in 1998, is meeting this need. Broadband shortwave (SW) and longwave radiance measurements taken by the CERES scanners at resolutions between 10 and 20 km on the Tropical Rainfall Measuring Mission (TRMM), Terra, and Aqua satellites are matched to simultaneous retrievals of cloud height, phase, particle size, water path, and optical depth OD from the TRMM Visible Infrared Scanner (VIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Besides aiding the interpretation of the broadband radiances, the CERES cloud properties are valuable for understanding cloud variations at a variety of scales. In this paper, the resulting CERES cloud data taken to date are averaged at several temporal scales to examine the temporal and spatial variability of the cloud properties on a global scale at a 1 resolution.

  1. A comparison of cloud motion winds from ATS 6 images with coinciding SMS 1 winds

    NASA Technical Reports Server (NTRS)

    Kuhlow, W. W.; Chatters, G. C.

    1978-01-01

    A methodology is developed for accurate measurement of cloud motion winds from the geosynchronous ATS 6 image data. Attitude changes between consecutive images (as a function of scan-line number) are accounted for in wind computations through measurement of the earth-edge displacements between the successive infrared images. Also, an image matching procedure is used to remove obvious and distracting image distortions. The availability of SMS imagery coinciding with ATS 6 imagery makes SMS an excellent reference against which the quality of ATS 6 winds can be tested. The resulting winds inferred from cloud displacement measurements taken from a sequence of the corrected images are found to agree better than 2 m/sec rms with winds measured from coincident SMS 1 imagery.

  2. 3D change detection at street level using mobile laser scanning point clouds and terrestrial images

    NASA Astrophysics Data System (ADS)

    Qin, Rongjun; Gruen, Armin

    2014-04-01

    Automatic change detection and geo-database updating in the urban environment are difficult tasks. There has been much research on detecting changes with satellite and aerial images, but studies have rarely been performed at the street level, which is complex in its 3D geometry. Contemporary geo-databases include 3D street-level objects, which demand frequent data updating. Terrestrial images provides rich texture information for change detection, but the change detection with terrestrial images from different epochs sometimes faces problems with illumination changes, perspective distortions and unreliable 3D geometry caused by the lack of performance of automatic image matchers, while mobile laser scanning (MLS) data acquired from different epochs provides accurate 3D geometry for change detection, but is very expensive for periodical acquisition. This paper proposes a new method for change detection at street level by using combination of MLS point clouds and terrestrial images: the accurate but expensive MLS data acquired from an early epoch serves as the reference, and terrestrial images or photogrammetric images captured from an image-based mobile mapping system (MMS) at a later epoch are used to detect the geometrical changes between different epochs. The method will automatically mark the possible changes in each view, which provides a cost-efficient method for frequent data updating. The methodology is divided into several steps. In the first step, the point clouds are recorded by the MLS system and processed, with data cleaned and classified by semi-automatic means. In the second step, terrestrial images or mobile mapping images at a later epoch are taken and registered to the point cloud, and then point clouds are projected on each image by a weighted window based z-buffering method for view dependent 2D triangulation. In the next step, stereo pairs of the terrestrial images are rectified and re-projected between each other to check the geometrical consistency between point clouds and stereo images. Finally, an over-segmentation based graph cut optimization is carried out, taking into account the color, depth and class information to compute the changed area in the image space. The proposed method is invariant to light changes, robust to small co-registration errors between images and point clouds, and can be applied straightforwardly to 3D polyhedral models. This method can be used for 3D street data updating, city infrastructure management and damage monitoring in complex urban scenes.

  3. Improved Cloud and Surface Properties By Combining Conventional and L-1 Satellite Imager Data

    NASA Astrophysics Data System (ADS)

    Minnis, P.; Doelling, D.; Nguyen, L.; Palikonda, R.; Spangenberg, D. A.; Hong, G.; Yi, Y.

    2011-12-01

    Imagers on geostationary (GEOSat) and low-earth orbiting (LEOSat) satellites are often used to derive information about clouds and the surface, but are limited in their angular coverage of a given scene by their particular orbits. A GEOSat views an area through its entire diurnal cycle covering the full range of solar zenith angles (SZAs) while viewing from a constant viewing zenith angle (VZA) and varying relative azimuth angle (RAA). Most polar-orbiting satellites are sun-synchronous and view a given area at one time of day from various VZAs and RAAs, but a over a small SZA range. A few imagers such as MISR or AATSR are on LEOSats and can provide views over a greater range of RAA and VZA, but are still constrained by SZA. The Deep Space Climate Observatory (DSCOVR) will orbit at the L-1 position in a near backscatter angle (~168) relative to the Earth and sun. It carries an imager, EPIC, that has several UV, visible, and near-infrared channels measuring radiances at a nadir 10-km resolution. Because it views most of the sunlit Earth at high frequency, it can provide unprecedented coverage of the daylight portion of the diurnal cycle for a given area at over the full range of SZAs and VZAs at a nearly constant RAA. Because of this coverage, pixels from the EPIC can be matched with those from any other satellite passing over the sunlit hemisphere. Although cloud information such as cloud amount, optical depth, and height can be derived from the EPIC channels, the combination of EPIC data with that from higher resolution GEOSats and LEOSats will be more useful than either by itself. Because of its low resolution and lack of infrared data, broken and scattered and cirrus cloud fields are likely to be misinterpreted using the EPIC data alone. Matching the more conventional satellite data and associated cloud products with the EPIC data will enhance the information from the EPIC as its field of view increases as 1/cos(VZA). The cloud heights derived from oxygen A and B bands will be improved by knowing the cloud fraction and type more accurately. Multiangle views from the matched satellite data will provide information about cirrus cloud particle habit, multilayer cloud conditions, and, possibly, the width of the droplet size spectrum. Better definition of clear areas and cloud conditions within the EPIC fields of view will be realized by inclusion of matched data, so that retrievals of other parameters such as leaf area index can be determined more accurately, without cloud contamination. This paper will explore these and other potential uses of combining real-time NASA Langley cloud data from LEOSats and GEOSats.

  4. An automated cloud detection method based on green channel of total sky visible images

    NASA Astrophysics Data System (ADS)

    Yang, J.; Min, Q.; Lu, W.; Yao, W.; Ma, Y.; Du, J.; Lu, T.

    2015-05-01

    Getting an accurate cloud cover state is a challenging task. In the past, traditional two-dimensional red-to-blue band methods have been widely used for cloud detection in total sky images. By analyzing the imaging principle of cameras, green channel has been selected to replace the 2-D red-to-blue band for total sky cloud detection. The brightness distribution in a total sky image is usually non-uniform, because of forward scattering and Mie scattering of aerosols, which results in increased detection errors in the circumsolar and near-horizon regions. This paper proposes an automatic cloud detection algorithm, "green channel background subtraction adaptive threshold" (GBSAT), which incorporates channel selection, background simulation, computation of solar mask and cloud mask, subtraction, adaptive threshold, and binarization. Several experimental cases show that the GBSAT algorithm is robust for all types of test total sky images and has more complete and accurate retrievals of visual effects than those found through traditional methods.

  5. Pushing the limits of imaging using patterned illumination

    NASA Astrophysics Data System (ADS)

    Rangarajan, Prasanna

    The image captured by an imaging system is subject to constraints imposed by the wave nature of light and the geometry of image formation. The former limits the resolving power of the imager while the latter results in a loss of size and range information. The body of work presented in this dissertation strives to overcome the aforementioned limits. The suite of techniques and apparatus ideas disclosed in the work afford imagers the unique ability to capture spatial detail lost to optical blur, while also recovering range information. A recurring theme in the work is the notion of imaging under patterned illumination. The Moire fringes arising from the heterodyning of the object detail and the patterned illumination, are used to improve the resolving power of the imager. The deformations in the phase of the detected illumination pattern, aid in the recovery of range information. The work furnishes a comprehensive mathematical model for imaging under patterned illumination that accommodates blur due to the imaging/illumination optics, and the perspective foreshortening observed at macroscopic scales. The model discloses the existence of a family of active stereo arrangements that jointly support super resolution (improvement of resolving power) and scene recovery (recovery of range information). The work also presents a new description of the theoretical basis for super resolution. The description confirms that an improvement in resolving power results from the computational engineering of the imager impulse response. The above notion is explored further, in developing a strategy for engineering the impulse response of an imager, using patterned illumination. It is also established that optical aberrations are not an impediment to super resolution. Furthermore, the work advances the state-of-the-art in scene recovery by establishing that a broader class of sinusoidal patterns may be used to recover range information, while circumventing the extensive calibration process employed by current approaches. The work concludes by examining an extreme example of super resolution using patterned illumination. In particular, a strategy that overcomes the severe anisotropy in the resolving power of a single-lens imager is examined. Spatial frequency analysis of the reconstructed image confirms the effectiveness of lattice illumination in engineering a computational imager with near isotropic resolving power.

  6. D Point Cloud Model Colorization by Dense Registration of Digital Images

    NASA Astrophysics Data System (ADS)

    Crombez, N.; Caron, G.; Mouaddib, E.

    2015-02-01

    Architectural heritage is a historic and artistic property which has to be protected, preserved, restored and must be shown to the public. Modern tools like 3D laser scanners are more and more used in heritage documentation. Most of the time, the 3D laser scanner is completed by a digital camera which is used to enrich the accurate geometric informations with the scanned objects colors. However, the photometric quality of the acquired point clouds is generally rather low because of several problems presented below. We propose an accurate method for registering digital images acquired from any viewpoints on point clouds which is a crucial step for a good colorization by colors projection. We express this image-to-geometry registration as a pose estimation problem. The camera pose is computed using the entire images intensities under a photometric visual and virtual servoing (VVS) framework. The camera extrinsic and intrinsic parameters are automatically estimated. Because we estimates the intrinsic parameters we do not need any informations about the camera which took the used digital image. Finally, when the point cloud model and the digital image are correctly registered, we project the 3D model in the digital image frame and assign new colors to the visible points. The performance of the approach is proven in simulation and real experiments on indoor and outdoor datasets of the cathedral of Amiens, which highlight the success of our method, leading to point clouds with better photometric quality and resolution.

  7. Automatic registration of Iphone images to LASER point clouds of the urban structures using shape features

    NASA Astrophysics Data System (ADS)

    Sirmacek, B.; Lindenbergh, R. C.; Menenti, M.

    2013-10-01

    Fusion of 3D airborne laser (LIDAR) data and terrestrial optical imagery can be applied in 3D urban modeling and model up-dating. The most challenging aspect of the fusion procedure is registering the terrestrial optical images on the LIDAR point clouds. In this article, we propose an approach for registering these two different data from different sensor sources. As we use iPhone camera images which are taken in front of the interested urban structure by the application user and the high resolution LIDAR point clouds of the acquired by an airborne laser sensor. After finding the photo capturing position and orientation from the iPhone photograph metafile, we automatically select the area of interest in the point cloud and transform it into a range image which has only grayscale intensity levels according to the distance from the image acquisition position. We benefit from local features for registering the iPhone image to the generated range image. In this article, we have applied the registration process based on local feature extraction and graph matching. Finally, the registration result is used for facade texture mapping on the 3D building surface mesh which is generated from the LIDAR point cloud. Our experimental results indicate possible usage of the proposed algorithm framework for 3D urban map updating and enhancing purposes.

  8. Multiscale vector fields for image pattern recognition

    NASA Technical Reports Server (NTRS)

    Low, Kah-Chan; Coggins, James M.

    1990-01-01

    A uniform processing framework for low-level vision computing in which a bank of spatial filters maps the image intensity structure at each pixel into an abstract feature space is proposed. Some properties of the filters and the feature space are described. Local orientation is measured by a vector sum in the feature space as follows: each filter's preferred orientation along with the strength of the filter's output determine the orientation and the length of a vector in the feature space; the vectors for all filters are summed to yield a resultant vector for a particular pixel and scale. The orientation of the resultant vector indicates the local orientation, and the magnitude of the vector indicates the strength of the local orientation preference. Limitations of the vector sum method are discussed. Investigations show that the processing framework provides a useful, redundant representation of image structure across orientation and scale.

  9. Orientation of Airborne Laser Scanning Point Clouds with Multi-View, Multi-Scale Image Blocks

    PubMed Central

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

    2009-01-01

    Comprehensive 3D modeling of our environment requires integration of terrestrial and airborne data, which is collected, preferably, using laser scanning and photogrammetric methods. However, integration of these multi-source data requires accurate relative orientations. In this article, two methods for solving relative orientation problems are presented. The first method includes registration by minimizing the distances between of an airborne laser point cloud and a 3D model. The 3D model was derived from photogrammetric measurements and terrestrial laser scanning points. The first method was used as a reference and for validation. Having completed registration in the object space, the relative orientation between images and laser point cloud is known. The second method utilizes an interactive orientation method between a multi-scale image block and a laser point cloud. The multi-scale image block includes both aerial and terrestrial images. Experiments with the multi-scale image block revealed that the accuracy of a relative orientation increased when more images were included in the block. The orientations of the first and second methods were compared. The comparison showed that correct rotations were the most difficult to detect accurately by using the interactive method. Because the interactive method forces laser scanning data to fit with the images, inaccurate rotations cause corresponding shifts to image positions. However, in a test case, in which the orientation differences included only shifts, the interactive method could solve the relative orientation of an aerial image and airborne laser scanning data repeatedly within a couple of centimeters. PMID:22454569

  10. Improvements in Near-Terminator and Nocturnal Cloud Masks using Satellite Image Data over the Atmospheric Radiation Measurement Sites

    NASA Technical Reports Server (NTRS)

    Trepte, Q. Z.; Minnis, P.; Heck, R. W.; Palikonda, R.

    2005-01-01

    Cloud detection using satellite measurements presents a big challenge near the terminator where the visible (VIS; 0.65 (micro)m) channel becomes less reliable and the reflected solar component of the solar infrared 3.9-(micro)m channel reaches very low signal-to-noise ratio levels. As a result, clouds are underestimated near the terminator and at night over land and ocean in previous Atmospheric Radiation Measurement (ARM) Program cloud retrievals using Geostationary Operational Environmental Satellite (GOES) imager data. Cloud detection near the terminator has always been a challenge. For example, comparisons between the CLAVR-x (Clouds from Advanced Very High Resolution Radiometer (AVHRR)) cloud coverage and Geoscience Laser Altimeter System (GLAS) measurements north of 60 degrees N indicate significant amounts of missing clouds from AVHRR because this part of the world was near the day/night terminator viewed by AVHRR. Comparisons between MODIS cloud products and GLAS at the same regions also shows the same difficulty in the MODIS cloud retrieval (Pavolonis and Heidinger 2005). Consistent detection of clouds at all times of day is needed to provide reliable cloud and radiation products for ARM and other research efforts involving the modeling of clouds and their interaction with the radiation budget. To minimize inconsistencies between daytime and nighttime retrievals, this paper develops an improved twilight and nighttime cloud mask using GOES-9, 10, and 12 imager data over the ARM sites and the continental United States (CONUS).

  11. Improvements in Near-Terminator and Nocturnal Cloud Masks using Satellite Imager Data over the Atmospheric Radiation Measurement Sites

    SciTech Connect

    Trepte, Q.Z.; Minnis, P.; Heck, P.W.; Palikonda, R.

    2005-03-18

    Cloud detection using satellite measurements presents a big challenge near the terminator where the visible (VIS; 0.65 {micro}m) channel becomes less reliable and the reflected solar component of the solar infrared 3.9-{micro}m channel reaches very low signal-to-noise ratio levels. As a result, clouds are underestimated near the terminator and at night over land and ocean in previous Atmospheric Radiation Measurement (ARM) Program cloud retrievals using Geostationary Operational Environmental Satellite (GOES) imager data. Cloud detection near the terminator has always been a challenge. For example, comparisons between the CLAVR-x (Clouds from Advanced Very High Resolution Radiometer [AVHRR]) cloud coverage and Geoscience Laser Altimeter System (GLAS) measurements north of 60{sup o}N indicate significant amounts of missing clouds from AVHRR because this part of the world was near the day/night terminator viewed by AVHRR. Comparisons between MODIS cloud products and GLAS at the same regions also shows the same difficulty in the MODIS cloud retrieval (Pavolonis and Heidinger 2005). Consistent detection of clouds at all times of day is needed to provide reliable cloud and radiation products for ARM and other research efforts involving the modeling of clouds and their interaction with the radiation budget. To minimize inconsistencies between daytime and nighttime retrievals, this paper develops an improved twilight and nighttime cloud mask using GOES-9, 10, and 12 imager data over the ARM sites and the continental United States (CONUS).

  12. On the camparability of cloud fractions derived from whole sky imager and ceilometer data

    SciTech Connect

    Rodriguez, D.

    1998-01-30

    The Atmospheric Radiation Measurement (ARM) Program`s most heavily instrumented site is its central facility in Lamont, OK. With respect to cloud observations, the instrumentation included a whole sky imager, ceilometers, lidar, millimeter cloud radar, microwave profilers, and radiosondes. Data from three of these instrument--the Whole Sky Imager (WSI), Belfort Laser Ceilometer (BLC) and Micropulse Lidar (MPL)-- are used in this study primarily to investigate the utility of using ceilometers, now strategically emplaced at four additional locations along the perimeter of the site.

  13. High speed synchrotron X-ray imaging of ultrasonic bubble cloud in liquid metal

    NASA Astrophysics Data System (ADS)

    Wang, C.; Tang, D.; Zhang, W.; Du, W.; Connolley, T.; Mi, J.

    2015-12-01

    This paper presents the real-time and in-situ synchrotron X-ray high speed imaging studies of ultrasound bubbles and bubble cloud in a liquid Sn-30%Cu alloy. The collective behaviour of the ultrasound bubbles generated by ultrasound powders of 60 W and 100W were successfully captured. The number density of the individual bubbles and the density of the continuous bubble cloud were calculated from the information extracted from the images sequences and presented for the first time for the liquid Sn-30%Cu alloy.

  14. Detection and tracking of gas clouds in an urban area by imaging infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Sabbah, Samer; Rusch, Peter; Gerhard, Jrn-Hinnrich; Harig, Roland

    2013-05-01

    The release of toxic industrial compounds in urban areas is a threat for the population and the environment. In order to supply emergency response forces with information about the released compounds after accidents or terrorist attacks, monitoring systems such as the scanning imaging spectrometer SIGIS 2 or the hyperspectral imager HI 90 were developed. Both systems are based on the method of infrared spectroscopy. The systems were deployed to monitor gas clouds released in the harbor area of Hamburg. The gas clouds were identified, visualized and quantified from a distance in real time. Using data of two systems it was possible to identify contaminated areas and to determine the source location.

  15. Cloud Ice Crystal Orientation Inferred from Global Precipitation Measurement (GPM) Microwave Imager

    NASA Astrophysics Data System (ADS)

    Gong, J.; Wu, D. L.; Evans, K. F.; Kim, K. M.

    2014-12-01

    Ice crystal orientation can produce significantly different scattering in vertically (V) and horizontally (H) polarized microwave radiances and affect the accuracy of cloud ice measurement. Designed to observe the precipitable-sized particles, GPM Microwave Imager (GMI) is used in this study to infer ice crystal orientation inside ice clouds. By identifying ice cloud scenes using the 183.33 GHz channel, we compare the 89 and 166 GHz radiances for their V-H differences. Ice cloud crystals are found highly polarized with V-H > 0 throughout the tropics and the mid-latitude jet regions. The V-H difference can be as large as 10% (5%) of the mean radiance at 166 GHz (89 GHz). The largest values generally occur over convective outflows, but decreasing in the vicinity of deep convective cores and remote thin cirrus regions. The negative V-H values prominently happen in the equator side of the winter hemisphere storm track regions. A polarized radiative transfer model is employed to interpret the observed polarization. Simulations with systematically oriented non-spherical ice particles can reproduce the observed V-H differences, while spherical or randomly oriented non-spherical particles cannot. This finding suggests that accurate cloud ice retrievals must take into account ice crystal orientation. The observed V-H relationship with cloud regimes may relate with vertical velocity, in-cloud turbulence, lightning, and other physical processes, which will be briefly discussed in this presentation.

  16. Characterization of aerosol-containing chemical simulant clouds using a sensitive, thermal infrared imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Hall, Jeffrey L.; D'Amico, Francis M.; Kolodzey, Steven J.; Qian, Jun; Polak, Mark L.; Westerberg, Karl; Chang, Clement S.

    2011-05-01

    A sensitive, ground-based thermal imaging spectrometer was deployed at the Army's Dugway Proving Ground to remotely monitor explosively released chemical-warfare-agent-simulant clouds from stand-off ranges of a few kilometers. The sensor has 128 spectral bands covering the 7.6 to 13.5 micron region. The measured cloud spectra clearly showed scattering of high-elevation-angle sky radiance by liquid aerosols or dust in the clouds: we present arguments that show why the scattering is most likely due to dust. This observation has significant implications for early detection of dust-laden chemical clouds. On one hand, detection algorithms must properly account for the scattered radiation component, which would include out-of-scene radiation components as well as a dust signature; on the other hand, this scattering gives rise to an enhanced "delta-T" for detection by a ground-based sensor.

  17. Atlas of relectance patterns for uniform earth and cloud surfaces (NIMBUS-7ERB-61 days)

    NASA Astrophysics Data System (ADS)

    Taylor, V. R.; Stowe, L. L.

    1984-07-01

    Scanning channel data of the Nimbus-7 ERB instrument have been combined with auxiliary information to describe the radiative characteristics of surfaces as observed through the atmosphere. This information has been recorded on the ERB 'Sub-Target Radiance Tapes' (STRT). A description of that data base and procedures for obtaining the data may be found in Stowe and Fromm (1983). Selected data from the STRTs have been sorted into eight uniform earth and cloud surface types. Diagrams illustrating the bi-directional reflectivity of these surfaces have been constructed. The observed dependence of albedo on solar zenith angle (SZA) is discussed and figures illustrating this dependence are given. An extensive list of references is also given. This report contains a complete set of reflectance diagrams (patterns) and tables listing the values that were used in their construction and interpretation.

  18. Automated estimation of mass eruption rate of volcanic eruption on satellite imagery using a cloud pattern recognition algorithm

    NASA Astrophysics Data System (ADS)

    Pouget, Solene; Jansons, Emile; Bursik, Marcus; Tupper, Andrew; Patra, Abani; Pitman, Bruce; Carn, Simon

    2014-05-01

    The need to detect and track the position of ash in the atmosphere has been highlighted in the past few years following the eruption Eyjafjallajokull. As a result, Volcanic Ash Advisory Centers (VAACs) are using Volcanic Ash Transport and Dispersion models (VATD) to estimate and predict the whereabouts of the ash in the atmosphere. However, these models require inputs of eruption source parameters, such as the mass eruption rate (MER), and wind fields, which are vital to properly model the ash movements. These inputs might change with time as the eruption enters different phases. This implies tracking the ash movement as conditions change, and new satellite imagery comes in. Thus, ultimately, the eruption must be detectable, regardless of changing eruption source and meteorological conditions. Volcanic cloud recognition can be particularly challenging, especially when meteorological clouds are present, which is typically the case in the tropics. Given the fact that a large fraction of the eruptions in the world happen in a tropical environment, we have based an automated volcanic cloud recognition algorithm on the fact that meteorological clouds and volcanic clouds behave differently. As a result, the pattern definition algorithm detects and defines volcanic clouds as different object types from meteorological clouds on satellite imagery. Following detection and definition, the algorithm then estimates the area covered by the ash. The area is then analyzed with respect to a plume growth rate methodology to get estimation of the volumetric and mass growth with time. This way, we were able to get an estimation of the MER with time, as plume growth is dependent on MER. To test our approach, we used the examples of two eruptions of different source strength, in two different climatic regimes, and for which therefore the weather during the eruption was quite different: Manam (Papua New Guinea) January 27 2005, which produced a stratospheric umbrella cloud and was difficult to distinguish from meteorological clouds, and Okmok (Alaska) July 12 2008, which was also an umbrella cloud, but started as an ash-rich cloud before getting a vapor rich pulse into the cloud. The new methods may in the future allow for fast, easy and automated detection of volcanic clouds as well as remote assessment of the MER with time, even for inaccessible volcanoes. The methods may thus provide an additional path to estimation of the ESP and the forecasting of ash cloud propagation with time as the eruption changes.

  19. Radionuclide cerebral perfusion imaging: Normal pattern

    SciTech Connect

    Goldsmith, S.J.; Stritzke, P.; Losonczy, M.; Vallabhajosula, S.; Holan, V.; DaCosta, M.; Muzinic, M.

    1991-12-31

    Regional cerebral perfusion imaging using a new class of {sup 99m}Tc and {sup 123}I labeled compounds which traverse the blood brain barrier and SPECT imaging technology provides an opportunity to assess this physiologic phenomenon during normal cerebral function and as a manifestation of disease in the central nervous system disease. These applications pose a challenge to the nuclear medicine physician for several reasons: (a) the complex and somewhat unfamiliar functional anatomy, (b) the marked regional differences in regional cerebral perfusion at rest, (c) the lack of understanding of the effect of variations in ambient conditions on regional cerebral perfusion. The difficulties in interpretation are augmented by the display itself. There is frequently no difficulty in differentiating between gray and white matter. However, the frequently used {open_quotes}hot body{close_quotes} color maps, introduce a good deal of contrast, producing displays with apparent interruption in regional cortical perfusion whereas black and white displays provide minimal contrast in the regional cortical activity. The authors sought to define how much variation in regional cerebral perfusion is {open_quotes}allowed{close_quotes} under controlled conditions, to establish a basis to interpret if changes in the environment, psychological interventions, or disease states are accompanied by a measurable change. 2 figs., 1 tab.

  20. Machine learning patterns for neuroimaging-genetic studies in the cloud.

    PubMed

    Da Mota, Benoit; Tudoran, Radu; Costan, Alexandru; Varoquaux, Gal; Brasche, Goetz; Conrod, Patricia; Lemaitre, Herve; Paus, Tomas; Rietschel, Marcella; Frouin, Vincent; Poline, Jean-Baptiste; Antoniu, Gabriel; Thirion, Bertrand

    2014-01-01

    Brain imaging is a natural intermediate phenotype to understand the link between genetic information and behavior or brain pathologies risk factors. Massive efforts have been made in the last few years to acquire high-dimensional neuroimaging and genetic data on large cohorts of subjects. The statistical analysis of such data is carried out with increasingly sophisticated techniques and represents a great computational challenge. Fortunately, increasing computational power in distributed architectures can be harnessed, if new neuroinformatics infrastructures are designed and training to use these new tools is provided. Combining a MapReduce framework (TomusBLOB) with machine learning algorithms (Scikit-learn library), we design a scalable analysis tool that can deal with non-parametric statistics on high-dimensional data. End-users describe the statistical procedure to perform and can then test the model on their own computers before running the very same code in the cloud at a larger scale. We illustrate the potential of our approach on real data with an experiment showing how the functional signal in subcortical brain regions can be significantly fit with genome-wide genotypes. This experiment demonstrates the scalability and the reliability of our framework in the cloud with a 2 weeks deployment on hundreds of virtual machines. PMID:24782753

  1. Machine learning patterns for neuroimaging-genetic studies in the cloud

    PubMed Central

    Da Mota, Benoit; Tudoran, Radu; Costan, Alexandru; Varoquaux, Gaël; Brasche, Goetz; Conrod, Patricia; Lemaitre, Herve; Paus, Tomas; Rietschel, Marcella; Frouin, Vincent; Poline, Jean-Baptiste; Antoniu, Gabriel; Thirion, Bertrand

    2014-01-01

    Brain imaging is a natural intermediate phenotype to understand the link between genetic information and behavior or brain pathologies risk factors. Massive efforts have been made in the last few years to acquire high-dimensional neuroimaging and genetic data on large cohorts of subjects. The statistical analysis of such data is carried out with increasingly sophisticated techniques and represents a great computational challenge. Fortunately, increasing computational power in distributed architectures can be harnessed, if new neuroinformatics infrastructures are designed and training to use these new tools is provided. Combining a MapReduce framework (TomusBLOB) with machine learning algorithms (Scikit-learn library), we design a scalable analysis tool that can deal with non-parametric statistics on high-dimensional data. End-users describe the statistical procedure to perform and can then test the model on their own computers before running the very same code in the cloud at a larger scale. We illustrate the potential of our approach on real data with an experiment showing how the functional signal in subcortical brain regions can be significantly fit with genome-wide genotypes. This experiment demonstrates the scalability and the reliability of our framework in the cloud with a 2 weeks deployment on hundreds of virtual machines. PMID:24782753

  2. Characterizing spatial and temporal patterns of cloud cover and fog inundation for the Northern Channel islands of California

    NASA Astrophysics Data System (ADS)

    Rastogi, Bharat

    The presence of low-lying stratocumulus clouds and fog has been known to modify biophysical and ecological properties in a variety of ecosystems in different climates. This is especially true for California's Channel Islands, where forests are frequently shaded by low-lying clouds or immersed in fog during warm and dry summer months. Previous studies suggest that clouds strongly modulate forest distributions as well as carbon and water budgets in these semi-arid environments by reducing solar insolation and raising relative humidity and thus reducing evapotranspiration, while also potentially supplying water directly to the landscape from fog-drip. While summertime fog and stratus cover in California's Channel Islands can ameliorate summer drought stress and enhance soil water budgets, they often have different spatial and temporal patterns. These differing patterns and the resulting shifts in relative ecological importance of fog and stratus are understudied. The overall objective of this study is to map spatial and temporal distributions of daytime cloud cover frequency for the California Channel Islands, and to predict probabilities of surface cloud (fog) contact and immersion for these islands. The results of this research are significant for water balance modeling, help explain vegetation patterns on the islands, and better identify locations where native vegetation restoration efforts are likely to be most successful.

  3. Optical Processing of Speckle Images with Bacteriorhodopsin for Pattern Recognition

    NASA Technical Reports Server (NTRS)

    Downie, John D.; Tucker, Deanne (Technical Monitor)

    1994-01-01

    Logarithmic processing of images with multiplicative noise characteristics can be utilized to transform the image into one with an additive noise distribution. This simplifies subsequent image processing steps for applications such as image restoration or correlation for pattern recognition. One particularly common form of multiplicative noise is speckle, for which the logarithmic operation not only produces additive noise, but also makes it of constant variance (signal-independent). We examine the optical transmission properties of some bacteriorhodopsin films here and find them well suited to implement such a pointwise logarithmic transformation optically in a parallel fashion. We present experimental results of the optical conversion of speckle images into transformed images with additive, signal-independent noise statistics using the real-time photochromic properties of bacteriorhodopsin. We provide an example of improved correlation performance in terms of correlation peak signal-to-noise for such a transformed speckle image.

  4. Cumulus Cloud Field Morphology and Spatial Patterns Derived from High Spatial Resolution Landsat Imagery.

    NASA Astrophysics Data System (ADS)

    Sengupta, S. K.; Welch, R. M.; Navar, M. S.; Berendes, T. A.; Chen, D. W.

    1990-12-01

    Detailed observations of cumulus cloud scales and processes are an essential ingredient in models that deal with (i) high spatial resolution cumulus ensembles; and (ii) parameterization of cloud radiative processes. The present investigation focuses on three aspects of the morphology of cumulus clouds: 1) the inhomogeneity as represented by the size distribution of clouds and cloud `holes,' 2) the nearest-neighbor relationships regarding their sizes and mutual distances, and 3) the scales of their clustering.Distributionwise, cloud size can best be represented by a mixture of two power laws. Clouds of diameter below 1 km have the slope parameter ranging from about 1.4 to 2.3, while larger clouds have slopes ranging from 2.1 to 4.75. Furthermore, these clouds are bifractal in nature. The break in power law and fractal dimension occurs at a size critical to the cloud-scale processes in the following sense. First, this is the cloud size that makes the largest contribution to the extent of cloud cover. Second, there are indications that this is the size at which clouds begin to modify their environment.Cloud inhomogeneities have significant impact on radiative fluxes. The size distribution of holes in the cumulus clouds studied here have a single slope power law with estimated slopes close to 3; these holes have single fractal dimensions. Furthermore, the results suggest that as the cloud field matures, there is an increase in the number and size of the inhomogeneities along with increasing cloud size.Nearest-neighbor relationships are studied from two different perspectives. First, the nearest-neighbor separation distance is modeled by four probability distributions: lognormal, gamma, extreme-value and Weibull. Lognormal appears to provide the best fit. Second, the nearest-neighbor pair sizes and the associated separation distance are studied using a co-occurrence frequency approach of spatial point processes using second-order statistics. The largest frequency of nearest-neighbor pairs occurs at a distance of 200-300 m, with the largest absolute differences in cloud size found at separations of about 500 m. At larger separations, there is a tendency for the larger clouds to be closer to other large clouds, apparently through the modification of the environment. Nonlinear dependence between the sizes of nearest-neighbor cloud pairs increases with increasing cloud size.Cumulus cloud clustering scales are determined by using the classical Greig-Smith quadrat analysis technique. Clustering scales of about 15, 29, and 59 km are found for most of the ten cloud fields studied.

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

    PubMed

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

    2009-01-01

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

  6. Cloud top structure of Venus revealed by Subaru/COMICS mid-infrared images

    NASA Astrophysics Data System (ADS)

    Sato, T. M.; Sagawa, H.; Kouyama, T.; Mitsuyama, K.; Satoh, T.; Ohtsuki, S.; Ueno, M.; Kasaba, Y.; Nakamura, M.; Imamura, T.

    2014-04-01

    We have investigated the cloud top structure of Venus by analyzing ground-based images obtained by the Cooled Mid-Infrared Camera and Spectrometer (COMICS), mounted on the 8.2-m Subaru Telescope. In this presentation, we will overview the observational results and discuss their interpretations.

  7. Geostationary imaging Fabry-Perot spectrometer (GIFS): measurement of clouds and trace gases

    NASA Astrophysics Data System (ADS)

    Yee, Jeng-Hwa; DeMajistre, Robert; Swartz, William H.; Morgan, M. Frank; Boldt, John D.; Skinner, Wilbert R.; Pitts, Michael C.; Hostetler, Chris A.

    2008-10-01

    Long-term measurements of the global distributions of clouds, trace gases, and surface reflectance are needed for the study and monitoring of global change and air quality. The Geostationary Imaging Fabry-Perot Spectrometer (GIFS) instrument is an example of a next-generation satellite remote sensing concept. GIFS is designed to be deployed on a geostationary satellite, where it can make continuous hemispheric imaging observations of cloud properties (including cloud top pressure, optical depth, and fraction), trace gas concentrations, such as tropospheric and boundary layer CO, and surface reflectance and pressure. These measurements can be made with spatial resolution, accuracy, and revisit time suitable for monitoring applications. It uses an innovative tunable imaging triple-etalon Fabry-Perot interferometer to obtain very high-resolution line-resolved spectral images of backscattered solar radiation, which contains cloud and trace gas information. An airborne GIFS prototype and the measurement technique have been successfully demonstrated in a recent field campaign onboard the NASA P3B based at Wallops Island, Virginia. In this paper, we present the preliminary GIFS instrument design and use GIFS prototype measurements to demonstrate the instrument functionality and measurement capabilities.

  8. Automatic image analysis for gene expression patterns of fly embryos

    PubMed Central

    Peng, Hanchuan; Long, Fuhui; Zhou, Jie; Leung, Garmay; Eisen, Michael B; Myers, Eugene W

    2007-01-01

    Background Staining the mRNA of a gene via in situ hybridization (ISH) during the development of a D. melanogaster embryo delivers the detailed spatio-temporal pattern of expression of the gene. Many biological problems such as the detection of co-expressed genes, co-regulated genes, and transcription factor binding motifs rely heavily on the analyses of these image patterns. The increasing availability of ISH image data motivates the development of automated computational approaches to the analysis of gene expression patterns. Results We have developed algorithms and associated software that extracts a feature representation of a gene expression pattern from an ISH image, that clusters genes sharing the same spatio-temporal pattern of expression, that suggests transcription factor binding (TFB) site motifs for genes that appear to be co-regulated (based on the clustering), and that automatically identifies the anatomical regions that express a gene given a training set of annotations. In fact, we developed three different feature representations, based on Gaussian Mixture Models (GMM), Principal Component Analysis (PCA), and wavelet functions, each having different merits with respect to the tasks above. For clustering image patterns, we developed a minimum spanning tree method (MSTCUT), and for proposing TFB sites we used standard motif finders on clustered/co-expressed genes with the added twist of requiring conservation across the genomes of 8 related fly species. Lastly, we trained a suite of binary-classifiers, one for each anatomical annotation term in a controlled vocabulary or ontology that operate on the wavelet feature representation. We report the results of applying these methods to the Berkeley Drosophila Genome Project (BDGP) gene expression database. Conclusion Our automatic image analysis methods recapitulate known co-regulated genes and give correct developmental-stage classifications with 99+% accuracy, despite variations in morphology, orientation, and focal plane suggesting that these techniques form a set of useful tools for the large-scale computational analysis of fly embryonic gene expression patterns. PMID:17634097

  9. Single-pixel optical imaging with compressed reference intensity patterns

    NASA Astrophysics Data System (ADS)

    Chen, Wen; Chen, Xudong

    2015-03-01

    Ghost imaging with single-pixel bucket detector has attracted more and more current attention due to its marked physical characteristics. However, in ghost imaging, a large number of reference intensity patterns are usually required for object reconstruction, hence many applications based on ghost imaging (such as tomography and optical security) may be tedious since heavy storage or transmission is requested. In this paper, we report that the compressed reference intensity patterns can be used for object recovery in computational ghost imaging (with single-pixel bucket detector), and object verification can be further conducted. Only a small portion (such as 2.0% pixels) of each reference intensity pattern is used for object reconstruction, and the recovered object is verified by using nonlinear correlation algorithm. Since statistical characteristic and speckle averaging property are inherent in ghost imaging, sidelobes or multiple peaks can be effectively suppressed or eliminated in the nonlinear correlation outputs when random pixel positions are selected from each reference intensity pattern. Since pixel positions can be randomly selected from each 2D reference intensity pattern (such as total measurements of 20000), a large key space and high flexibility can be generated when the proposed method is applied for authenticationbased cryptography. When compressive sensing is used to recover the object with a small number of measurements, the proposed strategy could still be feasible through further compressing the recorded data (i.e., reference intensity patterns) followed by object verification. It is expected that the proposed method not only compresses the recorded data and facilitates the storage or transmission, but also can build up novel capability (i.e., classical or quantum information verification) for ghost imaging.

  10. A Multi-Frequency Wide-Swath Spaceborne Cloud and Precipitation Imaging Radar

    NASA Technical Reports Server (NTRS)

    Li, Lihua; Racette, Paul; Heymsfield, Gary; McLinden, Matthew; Venkatesh, Vijay; Coon, Michael; Perrine, Martin; Park, Richard; Cooley, Michael; Stenger, Pete; Spence, Thomas; Retelny, Tom

    2016-01-01

    Microwave and millimeter-wave radars have proven their effectiveness in cloud and precipitation observations. The NASA Earth Science Decadal Survey (DS) Aerosol, Cloud and Ecosystems (ACE) mission calls for a dual-frequency cloud radar (W band 94 GHz and Ka-band 35 GHz) for global measurements of cloud microphysical properties. Recently, there have been discussions of utilizing a tri-frequency (KuKaW-band) radar for a combined ACE and Global Precipitation Measurement (GPM) follow-on mission that has evolved into the Cloud and Precipitation Process Mission (CaPPM) concept. In this presentation we will give an overview of the technology development efforts at the NASA Goddard Space Flight Center (GSFC) and at Northrop Grumman Electronic Systems (NGES) through projects funded by the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP). Our primary objective of this research is to advance the key enabling technologies for a tri-frequency (KuKaW-band) shared-aperture spaceborne imaging radar to provide unprecedented, simultaneous multi-frequency measurements that will enhance understanding of the effects of clouds and precipitation and their interaction on Earth climate change. Research effort has been focused on concept design and trade studies of the tri-frequency radar; investigating architectures that provide tri-band shared-aperture capability; advancing the development of the Ka band active electronically scanned array (AESA) transmitreceive (TR) module, and development of the advanced radar backend electronics.

  11. Automatic Pattern Extraction and Classification for Chromosome Images

    NASA Astrophysics Data System (ADS)

    Ming, Delie; Tian, Jinwen

    2010-07-01

    Chromosome image analysis and pattern classification is one of the essential tasks in genetic syndrome diagnoses. An automatic procedure is introduced for chromosome image analysis. The pale-path algorithm is proposed to segment touching and overlapping chromosomes. Medial axis is extracted by the middle point algorithm. Chromosome band is enhanced by the algorithm based on multiscale wavelets Bi-spline, and extracted by average gray profile, gradient profile and shape profile. The multilayer classifier is used to classify the chromosome pattern calculated by weighted density distribution algorithm. Experiment results demonstrate that the algorithms perform well.

  12. Traffic sign detection in MLS acquired point clouds for geometric and image-based semantic inventory

    NASA Astrophysics Data System (ADS)

    Soilán, Mario; Riveiro, Belén; Martínez-Sánchez, Joaquín; Arias, Pedro

    2016-04-01

    Nowadays, mobile laser scanning has become a valid technology for infrastructure inspection. This technology permits collecting accurate 3D point clouds of urban and road environments and the geometric and semantic analysis of data became an active research topic in the last years. This paper focuses on the detection of vertical traffic signs in 3D point clouds acquired by a LYNX Mobile Mapper system, comprised of laser scanning and RGB cameras. Each traffic sign is automatically detected in the LiDAR point cloud, and its main geometric parameters can be automatically extracted, therefore aiding the inventory process. Furthermore, the 3D position of traffic signs are reprojected on the 2D images, which are spatially and temporally synced with the point cloud. Image analysis allows for recognizing the traffic sign semantics using machine learning approaches. The presented method was tested in road and urban scenarios in Galicia (Spain). The recall results for traffic sign detection are close to 98%, and existing false positives can be easily filtered after point cloud projection. Finally, the lack of a large, publicly available Spanish traffic sign database is pointed out.

  13. Image Description with Local Patterns: An Application to Face Recognition

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Ahrary, Alireza; Kamata, Sei-Ichiro

    In this paper, we propose a novel approach for presenting the local features of digital image using 1D Local Patterns by Multi-Scans (1DLPMS). We also consider the extentions and simplifications of the proposed approach into facial images analysis. The proposed approach consists of three steps. At the first step, the gray values of pixels in image are represented as a vector giving the local neighborhood intensity distrubutions of the pixels. Then, multi-scans are applied to capture different spatial information on the image with advantage of less computation than other traditional ways, such as Local Binary Patterns (LBP). The second step is encoding the local features based on different encoding rules using 1D local patterns. This transformation is expected to be less sensitive to illumination variations besides preserving the appearance of images embedded in the original gray scale. At the final step, Grouped 1D Local Patterns by Multi-Scans (G1DLPMS) is applied to make the proposed approach computationally simpler and easy to extend. Next, we further formulate boosted algorithm to extract the most discriminant local features. The evaluated results demonstrate that the proposed approach outperforms the conventional approaches in terms of accuracy in applications of face recognition, gender estimation and facial expression.

  14. High-speed imaging of blood splatter patterns

    SciTech Connect

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J.; Levine, G.F.

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  15. Image analysis of dye stained patterns in soils

    NASA Astrophysics Data System (ADS)

    Bogner, Christina; Trancn y Widemann, Baltasar; Lange, Holger

    2013-04-01

    Quality of surface water and groundwater is directly affected by flow processes in the unsaturated zone. In general, it is difficult to measure or model water flow. Indeed, parametrization of hydrological models is problematic and often no unique solution exists. To visualise flow patterns in soils directly dye tracer studies can be done. These experiments provide images of stained soil profiles and their evaluation demands knowledge in hydrology as well as in image analysis and statistics. First, these photographs are converted to binary images classifying the pixels in dye stained and non-stained ones. Then, some feature extraction is necessary to discern relevant hydrological information. In our study we propose to use several index functions to extract different (ideally complementary) features. We associate each image row with a feature vector (i.e. a certain number of image function values) and use these features to cluster the image rows to identify similar image areas. Because images of stained profiles might have different reasonable clusterings, we calculate multiple consensus clusterings. An expert can explore these different solutions and base his/her interpretation of predominant flow mechanisms on quantitative (objective) criteria. The complete workflow from reading-in binary images to final clusterings has been implemented in the free R system, a language and environment for statistical computing. The calculation of image indices is part of our own package Indigo, manipulation of binary images, clustering and visualization of results are done using either build-in facilities in R, additional R packages or the LATEX system.

  16. Progressive image transmission using pyramid structure and pattern matching coding

    NASA Astrophysics Data System (ADS)

    Keissarian, F.

    2011-06-01

    A pyramidal data structure suited for coding and progressive transmission of images is proposed in this work. A mean pyramid representation of an image is first built up by forming a sequence of reduced-size images. A pyramid of difference images is then generated by subtracting the previous coded image from the original image at each level of the pyramid. Progressive transmission is achieved by sending all the nodes in the difference pyramid starting from the top level and ending at the bottom level. To gain efficiency, a pattern matching- based coding algorithm is applied to the difference pyramid of the image on a level-by-level basis. The proposed coding method, compresses the difference images by using a set of parameters computed based the visual activity of individual image blocks. The coding efficiency of the proposed technique along with the low computational complexity and simple parallel implementation of the pyramid approach allows for a high compression ratio as well as a good image quality. Satisfactory coded images have been obtained at bit rates in the range of 0.30 - 0.33 bits per pixel (bpp).

  17. Superresolution Imaging of Optical Vortices in a Speckle Pattern.

    PubMed

    Pascucci, Marco; Tessier, Gilles; Emiliani, Valentina; Guillon, Marc

    2016-03-01

    We characterize, experimentally, the intensity minima of a polarized high numerical aperture optical speckle pattern and the topological charges of the associated optical vortices. The negative of a speckle pattern is imprinted in a uniform fluorescent sample by photobleaching. The remaining fluorescence is imaged with superresolution stimulated emission depletion microscopy, which reveals subdiffraction fluorescence confinement at the center of optical vortices. The intensity statistics of saturated negative speckle patterns are predicted and measured. The charge of optical vortices is determined by controlling the handedness of circular polarization, and the creation or annihilation of a vortex pair along propagation is shown. PMID:26991179

  18. Venous pattern of polymicrogyria detected by susceptibility weighted imaging (SWI)

    PubMed Central

    Wagner, Franca; Weisstanner, Christian; Strozzi, Susi; Lang, Matthias F

    2015-01-01

    We report a case of a 9-year-old boy presenting with spastic-dystonic movement disorder of the right arm. MRI showed vast unilateral left-sided polymicrogyria (PMG) with perisylvian, temporal, frontal, and parietal location. Corresponding to the distinctly reduced gyration, the focal pattern of cortical veins in susceptibility weighted imaging (SWI) was absent due to missing sulcal depth. In contrast, adjacent regions with sufficient sulcal depth revealed a pattern with numerically increased and finer cortical veins. Therefore, with its atypical venous pattern SWI indicates an abnormal parenchymal anatomy and might be an additional helpful tool for diagnosing PMG. PMID:26668757

  19. Superresolution Imaging of Optical Vortices in a Speckle Pattern

    NASA Astrophysics Data System (ADS)

    Pascucci, Marco; Tessier, Gilles; Emiliani, Valentina; Guillon, Marc

    2016-03-01

    We characterize, experimentally, the intensity minima of a polarized high numerical aperture optical speckle pattern and the topological charges of the associated optical vortices. The negative of a speckle pattern is imprinted in a uniform fluorescent sample by photobleaching. The remaining fluorescence is imaged with superresolution stimulated emission depletion microscopy, which reveals subdiffraction fluorescence confinement at the center of optical vortices. The intensity statistics of saturated negative speckle patterns are predicted and measured. The charge of optical vortices is determined by controlling the handedness of circular polarization, and the creation or annihilation of a vortex pair along propagation is shown.

  20. Wide-Angle Imaging Lidar for Probing Spatially Complex Clouds: Instrument Development and Experimental Considerations

    NASA Astrophysics Data System (ADS)

    Love, S. P.; Davis, A. B.; Ho, C.; Polonsky, I. N.

    2004-05-01

    Understanding multiple scattering in clouds is important to both passive and lidar remote sensing, as well as to climate studies. When probing clouds using conventional lidar, where returning light is collected within a very narrow field of view about the laser beam, multiple scattering is generally regarded as a problem for which corrections must be made. But because it has thoroughly sampled the interior of the cloud, multiply-scattered light, especially high-order scattered light, carries much additional information that conventional lidar discards. The new technique of off-beam lidar seeks specifically to study this highly-scattered light, which can spread laterally as much as kilometer away from the input beam. Wide-Angle Imaging Lidar (WAIL) is the fullest realization of the off-beam lidar concept, combining high-resolution spatial imaging over a wide angular field together with high time resolution. WAIL data sets are, in essence, high-speed movies of the propagation of multiply-scattered light; mathematically, they embody the spatial and temporal Green function responses of the cloud. Here we describe the development of WAIL instrumentation at Los Alamos National Laboratory, including a WAIL implementation incorporating an ultra-high-speed (100 ps) microchannel-plate/crossed-delay-line imager and a more recent version using a gated intensified CCD capable of accommodating much higher photon rates. Strategies for performing WAIL measurements in daylight, prospects for WAIL measurements on highly complex broken cloud fields, and non-cloud applications for WAIL techniques ranging from probing sea ice to biomedical applications will also be discussed.

  1. Effects of clouds on the Earth radiation budget; Seasonal and inter-annual patterns

    NASA Technical Reports Server (NTRS)

    Dhuria, Harbans L.

    1992-01-01

    Seasonal and regional variations of clouds and their effects on the climatological parameters were studied. The climatological parameters surface temperature, solar insulation, short-wave absorbed, long wave emitted, and net radiation were considered. The data of climatological parameters consisted of about 20 parameters of Earth radiation budget and clouds of 2070 target areas which covered the globe. It consisted of daily and monthly averages of each parameter for each target area for the period, Jun. 1979 - May 1980. Cloud forcing and black body temperature at the top of the atmosphere were calculated. Interactions of clouds, cloud forcing, black body temperature, and the climatological parameters were investigated and analyzed.

  2. Automatic analysis of stereoscopic satellite image pairs for determination of cloud-top height and structure

    NASA Technical Reports Server (NTRS)

    Hasler, A. F.; Strong, J.; Woodward, R. H.; Pierce, H.

    1991-01-01

    Results are presented on an automatic stereo analysis of cloud-top heights from nearly simultaneous satellite image pairs from the GOES and NOAA satellites, using a massively parallel processor computer. Comparisons of computer-derived height fields and manually analyzed fields show that the automatic analysis technique shows promise for performing routine stereo analysis in a real-time environment, providing a useful forecasting tool by augmenting observational data sets of severe thunderstorms and hurricanes. Simulations using synthetic stereo data show that it is possible to automatically resolve small-scale features such as 4000-m-diam clouds to about 1500 m in the vertical.

  3. The method of cloud statistics measured with digital holographic imaging system

    NASA Astrophysics Data System (ADS)

    Li, Baosheng; Ma, Fei; Huang, Meng

    2015-11-01

    Due to the structure of clouds has so many complicated factors, the cloud seeding area is difficult to accurately determined. How to accurately understand the structures of the particle parameters has great significance for weather modification. Digital holographic technology is widely used in particle measurement, because it can realize the three-dimensional particle field measurement and get detail parameters. This paper, based on the research of the holographic reconstruction and image processing algorithm, calculate the equivalent diameter of particle, and obtain the distribution of the particles, for the estimation of the population parameter of particle is put forward a feasible method.

  4. Hiding a checkered-pattern carrier-screen image in a camouflaged halftone image

    NASA Astrophysics Data System (ADS)

    Shogenji, Rui; Ohtsubo, Junji

    2014-05-01

    As carrier-screen images, we have developed checkered-pattern carrier-screen images, which can be physically decoded by superimposing a checkered pattern. We also proposed a decoding method by image sampling with an ordinary compact digital camera. To obtain a better decoding result, each carrier-screen image should be output at a low resolution. However, secret information can be detected when you observe the image carefully. Thus, a hiding process is an important technique. In this paper, we propose an advanced hiding method by embedding the carrier-screen image into another significant image to generate a camouflaged halftone image. The proposed embedding method can be performed through a simple sequential process of blending and halftoning.

  5. Holographic atom imaging from experimental photoelectron angular distribution patterns

    SciTech Connect

    Terminello, L.J.; Lapiano-Smith, D.A.; Barton, J.J.; Petersen, B.L.; Shirley, D.A.

    1993-11-01

    One of the most challenging areas of materials research is the imaging of technologically relevant materials with microscopic and atomic-scale resolution. As part of the development of these methods, near-surface atoms in single crystals were imaged using core-level photoelectron holograms. The angle-dependent electron diffraction patterns that constitute an electron hologram were two-dimensionally transformed to create a three dimensional, real-space image of the neighboring scattering atoms. They have made use of a multiple-wavenumber, phased-summing method to improve the atom imaging capabilities of experimental photoelectron holography using the Cu(001) and Pt(111) prototype systems. These studies are performed to evaluate the potential of holographic atom imaging methods as structural probes of unknown materials.

  6. Segmentation of UAV-based images incorporating 3D point cloud information

    NASA Astrophysics Data System (ADS)

    Vetrivel, A.; Gerke, M.; Kerle, N.; Vosselman, G.

    2015-03-01

    Numerous applications related to urban scene analysis demand automatic recognition of buildings and distinct sub-elements. For example, if LiDAR data is available, only 3D information could be leveraged for the segmentation. However, this poses several risks, for instance, the in-plane objects cannot be distinguished from their surroundings. On the other hand, if only image based segmentation is performed, the geometric features (e.g., normal orientation, planarity) are not readily available. This renders the task of detecting the distinct sub-elements of the building with similar radiometric characteristic infeasible. In this paper the individual sub-elements of buildings are recognized through sub-segmentation of the building using geometric and radiometric characteristics jointly. 3D points generated from Unmanned Aerial Vehicle (UAV) images are used for inferring the geometric characteristics of roofs and facades of the building. However, the image-based 3D points are noisy, error prone and often contain gaps. Hence the segmentation in 3D space is not appropriate. Therefore, we propose to perform segmentation in image space using geometric features from the 3D point cloud along with the radiometric features. The initial detection of buildings in 3D point cloud is followed by the segmentation in image space using the region growing approach by utilizing various radiometric and 3D point cloud features. The developed method was tested using two data sets obtained with UAV images with a ground resolution of around 1-2 cm. The developed method accurately segmented most of the building elements when compared to the plane-based segmentation using 3D point cloud alone.

  7. A method to transfer speckle patterns for digital image correlation

    NASA Astrophysics Data System (ADS)

    Chen, Zhenning; Quan, Chenggen; Zhu, Feipeng; He, Xiaoyuan

    2015-09-01

    A simple and repeatable speckle creation method based on water transfer printing (WTP) is proposed to reduce artificial measurement error for digital image correlation (DIC). This technique requires water, brush, and a piece of transfer paper that is made of prefabricated decal paper, a protected sheet, and printed speckle patterns. The speckle patterns are generated and optimized via computer simulations, and then printed on the decal paper. During the experiments, operators can moisten the basement with water and the brush, so that digital patterns can be simply transferred to the carriers’ surfaces. Tensile experiments with an extended three-dimensional (3D) DIC system are performed to test and verify the validity of WTP patterns. It is shown that by comparing with a strain gage, the strain error is less than 50με in a uniform tensile test. From five carbon steel tensile experiments, Lüders bands in both WTP patterns and spray paint patterns are demonstrated to propagate symmetrically. In the necking part where the strain is up to 66%, WTP patterns are proved to adhere to the specimens well. Hence, WTP patterns are capable of maintaining coherence and adherence to the specimen surface. The transfer paper, working as the role of strain gage in the electrometric method, will contribute to speckle creation.

  8. Digital analysis of the fringe pattern images from biomedical objects

    NASA Astrophysics Data System (ADS)

    Jaronski, Jaroslaw W.; Podbielska, Halina; Kasprzak, Henryk T.

    1995-03-01

    Recent developments in optical, optoelectronic, and digital electronic imaging and metrology are creating opportunities for a new type of diagnostics methods and systems. Some of these techniques, established already in the field of technical and industrial non-destructive testing, have increasingly gained importance in biomedical research and may enter the clinical scene, as well. Even the laboratory investigations can have strong impact for further developments in this field. However, in experimental medicine the quantitative analysis of experimental data is sometimes required. When applying different interferometric methods, the obtained results are in the form of fringe pattern images. In this paper some of these methods, including holographic interferometry, laser interferometry and moire techniques are described and illustrated by experimental results. For acquisition and evaluation of the fringe pattern images, the Bioscan Optimas package from Bioscan, Incorporated of Edmonds, Wash., running under Microsoft Windows was used.

  9. Extracting Mobile Objects in Images Using a Velodyne LIDAR Point Cloud

    NASA Astrophysics Data System (ADS)

    Vallet, B.; Xiao, W.; Brdif, M.

    2015-03-01

    This paper presents a full pipeline to extract mobile objects in images based on a simultaneous laser acquisition with a Velodyne scanner. The point cloud is first analysed to extract mobile objects in 3D. This is done using Dempster-Shafer theory and it results in weights telling for each points if it corresponds to a mobile object, a fixed object or if no decision can be made based on the data (unknown). These weights are projected in an image acquired simultaneously and used to segment the image between the mobile and the static part of the scene.

  10. Low Clouds and Fog Characterization over Iberian Peninsula using Meteosat Second Generation Images

    NASA Astrophysics Data System (ADS)

    Sánchez, Beatriz; Maqueda, Gregorio

    2014-05-01

    Fog is defined as a collection of suspended water droplets or ice crystals in the air near the Earth's surface that lead to a reduction of horizontal visibility below 1 km (National Oceanic and Atmospheric Administration, 1995). Fog is a stratiform cloud with similar radiative characteristics, for this reason the difference between fog and low stratus clouds is of little importance for remote sensing applications. Fog and low clouds are important atmospheric phenomena, mainly because of their impact on traffic safety and air quality, acting as an obstruction to traffic at land, sea and in the air. The purpose of this work is to develop the method of fog/low clouds detection and analysis on nighttime using Meteosat Second Generation data. This study is focused on the characterization of these atmospheric phenomena in different study cases over the Iberian Peninsula with distinct orography. Firstly, fog/low clouds detection is implemented as a composition of three infrared channels 12.0, 10.8 and 3.9 µm from SEVIRI radiometer on board European geostationary satellite Meteosat (Meteosat-9). The algorithm of detection makes use of a combination of these channels and their differences by creating RGB composites images. On this way, it displays the spatial coverage and location of fog entities. Secondly, this technique allows separating pixels which are indicated as fog/low clouds from clear pixels, assessing the properties of individual pixels using appropriated thresholds of brightness temperature. Thus, it achieves a full analysis of the extent and distribution of fog and its evolution over time. The results of this study have been checked by using ground-based point measurements available as METAR data. Despite the flaws in this sort of inter-comparison approach, the outcome produces to accurate fog/low clouds detection. This work encompasses the way to obtain spatial information from this atmospheric phenomenon by means of satellite imagery.

  11. Estimating errors in cloud amount and cloud optical thickness due to limited spatial sampling using a satellite imager as a proxy for nadir-view sensors

    NASA Astrophysics Data System (ADS)

    Liu, Yinghui

    2015-07-01

    Cloud climatologies from space-based active sensors have been used in climate and other studies without their uncertainties specified. This study quantifies the errors in monthly mean cloud amount and optical thickness due to the limited spatial sampling of space-based active sensors. Nadir-view observations from a satellite imager, the Moderate Resolution Imaging Spectroradiometer (MODIS), serve as a proxy for those active sensors and observations within 10 of the sensor's nadir view serve as truth for data from 2003 to 2013 in the Arctic. June-July monthly mean cloud amount and liquid water and ice cloud optical thickness from MODIS for both observations are calculated and compared. Results show that errors increase with decreasing sample numbers for monthly means in cloud amount and cloud optical thickness. The root-mean-square error of monthly mean cloud amount from nadir-view observations increases with lower latitudes, with 0.7% (1.4%) at 80N and 4.2% (11.2%) at 60N using data from 2003 to 2013 (from 2012). For a 100 km resolution Equal-Area Scalable Earth Grid (EASE-Grid) cell of 1000 sample numbers, the absolute differences in these two monthly mean cloud amounts are less than 6.5% (9.0%, 11.5%) with an 80 (90, 95)%chance; such differences decrease to 4.0% (5.0%, 6.5%) with 5000 sample numbers. For a 100 km resolution EASE-Grid of 1000 sample numbers, the absolute differences in these two monthly mean cloud optical thicknesses are less than 2.7 (3.8) with a 90% chance for liquid water cloud (ice cloud); such differences decrease to 1.3 (1.0) for 5000 sample numbers. The uncertainties in monthly mean cloud amount and optical thickness estimated in this study may provide useful information for applying cloud climatologies from active sensors in climate studies and suggest the need for future spaceborne active sensors with a wide swath.

  12. Diurnal cloud-to-ground lightning patterns in Arizona during the southwest monsoon

    SciTech Connect

    Watson, A.I.; Lopez, R.E.; Holle, R.L.

    1994-08-01

    Cloud-to-ground (CG) lightning shows great variability across Arizona from one year to the next as well as from one day to the next. Availability of moisture, location of the subtropical ridge axis, transitory troughs in both the westerlies and easterlies, and low-level moisture surges from the Gulf of California can affect thunderstorm occurrence, which, in turn, will affect lightning production. Diurnal CG lightning patterns in Arizona are also determined by daily heating cycles and topography. Six years of Bureau of Land Management CG flash data are used in this investigation. In Arizona, lightning usually starts first, on a daily basis, in the plateau region and extends in an arc from the White Mountains of eastern Arizona westward across the Mogollon Rim and then northward onto the Kaibab Plateau of northern Arizona. Flash activity moves in a more or less continuous fashion off the plateau, south and westward down the topography gradient, and enters the lower desert by early evening. At the same time, flash activity develops in the highlands of southeast Arizona and moves west-northwestward, reaching the lower desert by late afternoon. Precipitation and lightning are well correlated, except that precipitation seems to linger longer than lightning, probably due to the occasional development of mesoscale convective systems, which produce light stratiform precipitation during their dissipation stage.

  13. Data integration: Combined imaging and electrophysiology data in the cloud.

    PubMed

    Kini, Lohith G; Davis, Kathryn A; Wagenaar, Joost B

    2016-01-01

    There has been an increasing effort to correlate electrophysiology data with imaging in patients with refractory epilepsy over recent years. IEEG.org provides a free-access, rapidly growing archive of imaging data combined with electrophysiology data and patient metadata. It currently contains over 1200 human and animal datasets, with multiple data modalities associated with each dataset (neuroimaging, EEG, EKG, de-identified clinical and experimental data, etc.). The platform is developed around the concept that scientific data sharing requires a flexible platform that allows sharing of data from multiple file formats. IEEG.org provides high- and low-level access to the data in addition to providing an environment in which domain experts can find, visualize, and analyze data in an intuitive manner. Here, we present a summary of the current infrastructure of the platform, available datasets and goals for the near future. PMID:26044858

  14. Evaluating EUV mask pattern imaging with two EUV microscopes

    SciTech Connect

    Goldberg, Kenneth A.; Takase, Kei; Naulleau, Patrick P.; Han, Hakseung; Barty, Anton; Kinoshita, Hiroo; Hamamoto, Kazuhiro

    2008-02-26

    Aerial image measurement plays a key role in the development of patterned reticles for each generation of lithography. Studying the field transmitted (reflected) from EUV masks provides detailed information about potential disruptions caused by mask defects, and the performance of defect repair strategies, without the complications of photoresist imaging. Furthermore, by measuring the continuously varying intensity distribution instead of a thresholded, binary resist image, aerial image measurement can be used as feedback to improve mask and lithography system modeling methods. Interest in EUV, at-wavelength, aerial image measurement lead to the creation of several research tools worldwide. These tools are used in advanced mask development work, and in the evaluation of the need for commercial at-wavelength inspection tools. They describe performance measurements of two such tools, inspecting the same EUV mask in a series of benchmarking tests that includes brightfield and darkfield patterns. One tool is the SEMATECH Berkeley Actinic Inspection Tool (AIT) operating on a bending magnet beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. The AIT features an EUV Fresnel zoneplate microscope that emulates the numerical aperture of a 0.25-NA stepper, and projects the aerial image directly onto a CCD camera, with 700x magnification. The second tool is an EUV microscope (EUVM) operating at the NewSUBARU synchrotron in Hyogo, Japan. The NewSUBARU tool projects the aerial image using a reflective, 30x Schwarzschild objective lens, followed by a 10-200x x-ray zooming tube. The illumination conditions and the imaging etendue are different for the two tools. The benchmarking measurements were used to determine many imaging and performance properties of the tools, including resolution, modulation transfer function (MTF), aberration magnitude, aberration field-dependence (including focal-plane tilt), illumination uniformity, line-edge roughness, and flare. These measurements reveal the current state of the art in at-wavelength inspection performance, and will be a useful reference as performance improves over time.

  15. Accelerating statistical image reconstruction algorithms for fan-beam x-ray CT using cloud computing

    NASA Astrophysics Data System (ADS)

    Srivastava, Somesh; Rao, A. Ravishankar; Sheinin, Vadim

    2011-03-01

    Statistical image reconstruction algorithms potentially offer many advantages to x-ray computed tomography (CT), e.g. lower radiation dose. But, their adoption in practical CT scanners requires extra computation power, which is traditionally provided by incorporating additional computing hardware (e.g. CPU-clusters, GPUs, FPGAs etc.) into a scanner. An alternative solution is to access the required computation power over the internet from a cloud computing service, which is orders-of-magnitude more cost-effective. This is because users only pay a small pay-as-you-go fee for the computation resources used (i.e. CPU time, storage etc.), and completely avoid purchase, maintenance and upgrade costs. In this paper, we investigate the benefits and shortcomings of using cloud computing for statistical image reconstruction. We parallelized the most time-consuming parts of our application, the forward and back projectors, using MapReduce, the standard parallelization library on clouds. From preliminary investigations, we found that a large speedup is possible at a very low cost. But, communication overheads inside MapReduce can limit the maximum speedup, and a better MapReduce implementation might become necessary in the future. All the experiments for this paper, including development and testing, were completed on the Amazon Elastic Compute Cloud (EC2) for less than $20.

  16. Comparison of eye imaging pattern recognition using neural network

    NASA Astrophysics Data System (ADS)

    Bukhari, W. M.; Syed A., M.; Nasir, M. N. M.; Sulaima, M. F.; Yahaya, M. S.

    2015-05-01

    The beauty of eye recognition system that it is used in automatic identifying and verifies a human weather from digital images or video source. There are various behaviors of the eye such as the color of the iris, size of pupil and shape of the eye. This study represents the analysis, design and implementation of a system for recognition of eye imaging. All the eye images that had been captured from the webcam in RGB format must through several techniques before it can be input for the pattern and recognition processes. The result shows that the final value of weight and bias after complete training 6 eye images for one subject is memorized by the neural network system and be the reference value of the weight and bias for the testing part. The target classifies to 5 different types for 5 subjects. The eye images can recognize the subject based on the target that had been set earlier during the training process. When the values between new eye image and the eye image in the database are almost equal, it is considered the eye image is matched.

  17. Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data during the Mixed-Phase Arctic Cloud Experiment

    SciTech Connect

    Spangenberg, D.; Minnis, P.; Shupe, M.; Uttal, T.; Poellot, M.

    2005-03-18

    Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-{micro}m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based cloud phase retrievals over the ARM North Slope of Alaska (NSA) Barrow site and to in-situ data taken from University of North Dakota Citation (CIT) aircraft which flew during the Mixed-Phase Arctic Cloud Experiment (MPACE). It will be shown that the IRTST and WVT11P combined to form the AMPHM can achieve a relative high accuracy of phase discrimination compared to the surface-based retrievals. Since it only uses MODIS WV and IR channels, the AMPHM is robust in the sense that it can be applied to daytime, twilight, and nighttime scenes with no discontinuities in the output phase.

  18. Pattern recognition of magnetic resonance images with application to atherosclerosis

    SciTech Connect

    Carman, C.S.

    1989-01-01

    Magnetic resonance imaging provides excellent soft tissue contrast enabling the non-invasive visualization of soft tissue diseases. The quantification of tissues visible in MR images would significantly increase the diagnostic information available. While tissue selection methods exist for CT images, those same methods do not work with MR images. This dissertation focuses on the application of image processing and pattern recognition techniques to MR images for the identification and quantification of soft tissues, atherosclerosis in particular. Atherosclerosis is a chronic disease of human arteries responsible for significant mortality and medical expense. Current diagnostic methods are invasive and carry significant risk. Supervised pattern recognition methods were investigated for tissue identification in MR images. The classifiers were trained A Fisher linear classifier successfully identified the tissues of interest from MR images of excised arteries, performing better than a minimum distance to the means classifier. Quantitative measures of the disease state were computed from the results and 3-D displays were generated of the diseased anatomy. For tissue in vivo, adequate histology can be difficult to collect, increasing the difficulty of training the classifiers and making the results less accurate. Cluster analysis was used in this dissertation to generate the training information. A new cluster analysis method was developed. ISODATA was modified to use hierarchical stopping rules. The new method was tested in a Monte Carlo study and with real world data sets. Comparisons were made with published methods using the same data. An information theoretic criterion, the CAIC, was found to be an excellent criteria for hierarchical stopping rules.

  19. BOREAS AFM-6 NOAA/ETL 35 GHz Cloud/Turbulence Radar GIF Images

    NASA Technical Reports Server (NTRS)

    Martner, Brooks E.; Newcomer, Jeffrey A. (Editor); Hall, Forrest G.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-6 team from the National Oceanic and Atmospheric Administration/Environment Technology Laboratory (NOAA/ETL) operated a 35-GHz cloud-sensing radar in the Northern Study Area (NSA) near the Old Jack Pine (OJP) tower from 16 Jul 1994 to 08 Aug 1994. This data set contains a time series of GIF images that show the structure of the lower atmosphere. The NOAA/ETL 35-GHz cloud/turbulence radar GIF images are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  20. Mitigating illumination gradients in a SAR image based on the image data and antenna beam pattern

    DOEpatents

    Doerry, Armin W.

    2013-04-30

    Illumination gradients in a synthetic aperture radar (SAR) image of a target can be mitigated by determining a correction for pixel values associated with the SAR image. This correction is determined based on information indicative of a beam pattern used by a SAR antenna apparatus to illuminate the target, and also based on the pixel values associated with the SAR image. The correction is applied to the pixel values associated with the SAR image to produce corrected pixel values that define a corrected SAR image.

  1. Retrieval of Cloud Phase and Crystal Habit from Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) Data

    SciTech Connect

    McFarlane, Sally A.; Marchand, Roger T.; Ackerman, Thomas P.

    2005-07-22

    A method of retrieving cloud phase and the dominant ice crystal habit from radiances measured by the Multi-angle Imaging Spectro-Radiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) has been developed. The retrieval method takes advantage of the differences in the phase function of various particle shapes as a function of scattering angle. Three case studies are presented which illustrate the retrieval method. A comparison with semi-coincident in situ observations for one case study indicates that the retrieved crystal habits are consistent with the observations.

  2. Component pattern analysis of chemicals using multispectral THz imaging system

    NASA Astrophysics Data System (ADS)

    Kawase, Kodo; Ogawa, Yuichi; Watanabe, Yuki

    2004-04-01

    We have developed a novel basic technology for terahertz (THz) imaging, which allows detection and identification of chemicals by introducing the component spatial pattern analysis. The spatial distributions of the chemicals were obtained from terahertz multispectral transillumination images, using absorption spectra previously measured with a widely tunable THz-wave parametric oscillator. Further we have applied this technique to the detection and identification of illicit drugs concealed in envelopes. The samples we used were methamphetamine and MDMA, two of the most widely consumed illegal drugs in Japan, and aspirin as a reference.

  3. Multi-Scale Fractal Analysis of Image Texture and Pattern

    NASA Technical Reports Server (NTRS)

    Emerson, Charles W.

    1998-01-01

    Fractals embody important ideas of self-similarity, in which the spatial behavior or appearance of a system is largely independent of scale. Self-similarity is defined as a property of curves or surfaces where each part is indistinguishable from the whole, or where the form of the curve or surface is invariant with respect to scale. An ideal fractal (or monofractal) curve or surface has a constant dimension over all scales, although it may not be an integer value. This is in contrast to Euclidean or topological dimensions, where discrete one, two, and three dimensions describe curves, planes, and volumes. Theoretically, if the digital numbers of a remotely sensed image resemble an ideal fractal surface, then due to the self-similarity property, the fractal dimension of the image will not vary with scale and resolution. However, most geographical phenomena are not strictly self-similar at all scales, but they can often be modeled by a stochastic fractal in which the scaling and self-similarity properties of the fractal have inexact patterns that can be described by statistics. Stochastic fractal sets relax the monofractal self-similarity assumption and measure many scales and resolutions in order to represent the varying form of a phenomenon as a function of local variables across space. In image interpretation, pattern is defined as the overall spatial form of related features, and the repetition of certain forms is a characteristic pattern found in many cultural objects and some natural features. Texture is the visual impression of coarseness or smoothness caused by the variability or uniformity of image tone or color. A potential use of fractals concerns the analysis of image texture. In these situations it is commonly observed that the degree of roughness or inexactness in an image or surface is a function of scale and not of experimental technique. The fractal dimension of remote sensing data could yield quantitative insight on the spatial complexity and information content contained within these data. A software package known as the Image Characterization and Modeling System (ICAMS) was used to explore how fractal dimension is related to surface texture and pattern. The ICAMS software was verified using simulated images of ideal fractal surfaces with specified dimensions. The fractal dimension for areas of homogeneous land cover in the vicinity of Huntsville, Alabama was measured to investigate the relationship between texture and resolution for different land covers.

  4. Etiology of the obstructive pattern in hepatobiliary imaging

    SciTech Connect

    Hughes, K.S.; Marrangoni, A.G.; Turbiner, E.

    1984-04-01

    The records of all patients undergoing hepatobiliary imaging with technetion radioisotopes at our hospital from January 1980 to March 1983 were reviewed and 29 scans met the criteria for a pattern consistent with complete biliary tract obstruction. Biliary tract obstruction (due to choledocholithiasis, primary or secondary carcinoma involving the common bile duct, and pancreatitis) was documented in 24 of these patients. However, the remaining five patients had a patent common bile duct, and the etiologic factor was intrahepatic cholestasis secondary to sepsis in four and peritonitis in one. A classification of altered biliary dynamics in hepatobiliary imaging, which is based on the classification of jaundice, is proposed.

  5. Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo

    PubMed Central

    McCoy, Daniel T.; Burrows, Susannah M.; Wood, Robert; Grosvenor, Daniel P.; Elliott, Scott M.; Ma, Po-Lun; Rasch, Phillip J.; Hartmann, Dennis L.

    2015-01-01

    Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties—ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations affect not only cloud properties themselves but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. It is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed Nd. Enhanced Nd is spatially correlated with regions of high chlorophyll a, and the spatiotemporal variability in Nd is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35o to 45oS) and by organic matter in sea spray aerosol at higher latitudes (45o to 55oS). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m–2 over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere. PMID:26601216

  6. Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo.

    PubMed

    McCoy, Daniel T; Burrows, Susannah M; Wood, Robert; Grosvenor, Daniel P; Elliott, Scott M; Ma, Po-Lun; Rasch, Phillip J; Hartmann, Dennis L

    2015-07-01

    Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties-ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration N d of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations affect not only cloud properties themselves but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. It is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed N d. Enhanced N d is spatially correlated with regions of high chlorophyll a, and the spatiotemporal variability in N d is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35(o) to 45(o)S) and by organic matter in sea spray aerosol at higher latitudes (45(o) to 55(o)S). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m(-2) over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere. PMID:26601216

  7. Natural Aerosols Explain Seasonal and Spatial Patterns of Southern Ocean Cloud Albedo

    SciTech Connect

    McCoy, Daniel; Burrows, Susannah M.; Wood, R.; Grosvenor, Daniel P.; Elliott, Scott; Ma, Po-Lun; Rasch, Philip J.; Hartmann, Dennis L.

    2015-07-17

    Small particles called aerosols act as nucleation sites for cloud drop formation, affecting clouds and cloud properties – ultimately influencing the cloud dynamics, lifetime, water path and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations not only affect cloud properties themselves, but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. Here, it is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed Nd. Enhanced Nd over regions of high biological activity is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35-45°S) and by organic matter in sea spray aerosol at higher latitudes (45-55°S). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m-2 over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere.

  8. Pattern recognition of transillumination images for diagnosis of rheumatoid arthritis

    NASA Astrophysics Data System (ADS)

    Bauer, Joanna; Boerner, Ewa; Podbielska, Halina; Suchwalko, Artur

    2005-09-01

    In this work the statistical pattern recognition methods were applied for evaluation of transillumination images of interphalangeal joints of patients suffering from rheumatoid arthritis. Special portable apparatus was constructed for performing the transillumination examination. It consisted of He-Ne laser with optics for collimated illumination, special holder for placing the finger (perpendicular to optical axis, dorsal site towards camera), and CCD camera with memory stick. 20 ill patients and 20 healthy volunteers were examined. The captured images with 1152x864 resolution were converted into the gray level pictures and analyzed by means of statistical pattern recognition method. Principal Component Analysis (PCA) and cluster analysis by use of 1-NN method (1 Nearest Neighbour) were applied for classification. The recognition system was able to differentiate correctly between healthy and ill subjects with 72.35% accuracy in case the data base composed of 40 persons.

  9. Cloud Ozone Dust Imager (CODI). Volume 1; Investigation and Technical Plan

    NASA Technical Reports Server (NTRS)

    Clancy, R. Todd; Dusenbery, Paul; Wolff, Michael; James, Phil; Allen, Mark; Goguen, Jay; Kahn, Ralph; Gladstone, Rany; Murphy, Jim

    1995-01-01

    The Cloud Ozone Dust Imager (CODI) is proposed to investigate the current climatic balance of the Mars atmosphere, with particular emphasis on the important but poorly understood roles which dust and water ice aerosols play in this balance. The large atmospheric heating (20-50 K) resulting from global dust storms around Mars perihelion is well recognized. However, groundbased observations of Mars atmospheric temperatures, water vapor, and clouds since the Viking missions have identified a much colder, cloudier atmosphere around Mars aphelion that may prove as important as global dust storms in determining the interannual and long-term behavior of the Mars climate. The key climate issues CODI is designed to investigate are: 1) the degree to which non-linear interactions between atmospheric dust heating, water vapor saturation, and cloud nucleation influence the seasonal and interannual variability of the Mars atmosphere, and 2) whether the strong orbital forcing of atmospheric dust loading, temperatures and water vapor saturation determines the long-term balance of Mars water, as reflected in the north-south hemispheric asymmetries of atmospheric water vapor and polar water ice abundances. The CODI experiment will measure the daily, seasonal and (potentially) interannual variability of atmospheric dust and cloud opacities, and the key physical properties of these aerosols which determine their role in the climate cycles of Mars. CODI is a small (1.2 kg), fixed pointing camera, in which four wide-angle (+/- 70 deg) lenses illuminate fixed filters and CCD arrays. Simultaneous sky/surface imaging of Mars is obtained at an angular resolution of 0.28 deg/pixel for wavelengths of 255, 336, 502, and 673 nm (similar to Hubble Space Telescope filters). These wavelengths serve to measure atmospheric ozone (255 and 336 nm), discriminate ice and dust aerosols (336 and 673 nm), and construct color images (336, 502, and 673 nm). The CODI images are detected on four 512 x 512 pixel arrays, as partitioned on two 1024 x 1024 CCD's operated in frame transfer mode. The center of the CODI field-of-view is canted 40 deg from the zenith direction to obtain sky brightness measurements and a 20 deg surface field-of-view. Daily image observations will be conducted when the Sun is greater than or equal to 5 deg outside the edge of the CODI field-of-view, and twilight and nighttime imaging will obtained on a weekly basis. The 673 nm channel includes a polarizer wheel to obtain sky/surface polarimetry. A dust cover protects the entire lens assemblies of all four CODI channels. This opaque dust cover, which is normally opened for CODI imaging, includes a small fixed mirror and transparent window positioned above the 673 nm lens, to redirect the 673 nm field-of-view to the surface for descent imaging. Fixed pointing, internal data buffering, low operating power (2-4 W for less than or equal to 30 seconds), selective data transmission, and simple operational characteristics of the CODI experiment place minimum resource and operational demands on the Mars Surveyor 1998 lander. The CODI science goals are optimized for, but not restricted to, a low-latitude landing site (20 deg S-30 deg N). The primary CODI measurement objectives are the opacities, wave forms, particle properties (size, shape, and alignment), and heights of clouds; the opacities, particle properties, and vertical distribution of dust; and the opacity and vertical distribution of ozone. The variability of cloud, ozone, and dust opacities will be determined on diurnal, daily, and seasonal timescales. Wind velocities will be determined from cloud motions and wave characteristics; and the temporal variability of atmospheric water vapor, with limited altitude information, will be inferred from the CODI ozone observations. Secondary measurement objectives include limited descent imaging capability, surface uv-visible photometry and polarimetry, photochemistry, and meteorite infall rates.

  10. Robust Texture Image Representation by Scale Selective Local Binary Patterns.

    PubMed

    Guo, Zhenhua; Wang, Xingzheng; Zhou, Jie; You, Jane

    2016-02-01

    Local binary pattern (LBP) has successfully been used in computer vision and pattern recognition applications, such as texture recognition. It could effectively address grayscale and rotation variation. However, it failed to get desirable performance for texture classification with scale transformation. In this paper, a new method based on dominant LBP in scale space is proposed to address scale variation for texture classification. First, a scale space of a texture image is derived by a Gaussian filter. Then, a histogram of pre-learned dominant LBPs is built for each image in the scale space. Finally, for each pattern, the maximal frequency among different scales is considered as the scale invariant feature. Extensive experiments on five public texture databases (University of Illinois at Urbana-Champaign, Columbia Utrecht Database, Kungliga Tekniska Hgskolan-Textures under varying Illumination, Pose and Scale, University of Maryland, and Amsterdam Library of Textures) validate the efficiency of the proposed feature extraction scheme. Coupled with the nearest subspace classifier, the proposed method could yield competitive results, which are 99.36%, 99.51%, 99.39%, 99.46%, and 99.71% for UIUC, CUReT, KTH-TIPS, UMD, and ALOT, respectively. Meanwhile, the proposed method inherits simple and efficient merits of LBP, for example, it could extract scale-robust feature for a 200200 image within 0.24 s, which is applicable for many real-time applications. PMID:26685235

  11. Imaging spatial correlations of Rydberg excitations in cold atom clouds

    NASA Astrophysics Data System (ADS)

    Schwarzkopf, Andrew; Anderson, David; Raithel, Georg

    2012-06-01

    We measure correlations between excitation positions in cold Rydberg gases. We have previously observedootnotetextmark[2] Rydberg-blockade-induced structures in the Rydberg pair correlation function similar to those predicted in.ootnotetextmark[3] Here, we study the effect of Coulomb repulsion after field ionization, which could possibly influence the pair correlation measurement. We have simulated the ion trajectories in our chamber and determined that Coulomb repulsion did not play a role in any of our previous experiments. However, with higher magnification we expect to observe this effect as well. In the experiment, we already have obtained a magnification increase by about a factor of two, and progress towards even higher magnification is still being made. We will report on our progress in imaging smaller structures in the pair correlation function, induced by Coulomb repulsion and possibly by adiabatic Rydberg crystal formation.ootnotetextmark[4] ootnotetext[2]A. Schwarzkopf et al. Phys. Rev. Lett. 107, no. 10 (2011): 103001. ootnotetext[3]F. Robicheaux and J. Hernandez. Phys. Rev. A 72, 63403, 1-4 (2005). ootnotetext[4]T. Pohl et al. Phys. Rev. Lett. 104, no. 4 (January 27, 2010): 043002.

  12. Reconstruction of Indoor Models Using Point Clouds Generated from Single-Lens Reflex Cameras and Depth Images

    NASA Astrophysics Data System (ADS)

    Tsai, F.; Wu, T.-S.; Lee, I.-C.; Chang, H.; Su, A. Y. S.

    2015-05-01

    This paper presents a data acquisition system consisting of multiple RGB-D sensors and digital single-lens reflex (DSLR) cameras. A systematic data processing procedure for integrating these two kinds of devices to generate three-dimensional point clouds of indoor environments is also developed and described. In the developed system, DSLR cameras are used to bridge the Kinects and provide a more accurate ray intersection condition, which takes advantage of the higher resolution and image quality of the DSLR cameras. Structure from Motion (SFM) reconstruction is used to link and merge multiple Kinect point clouds and dense point clouds (from DSLR color images) to generate initial integrated point clouds. Then, bundle adjustment is used to resolve the exterior orientation (EO) of all images. Those exterior orientations are used as the initial values to combine these point clouds at each frame into the same coordinate system using Helmert (seven-parameter) transformation. Experimental results demonstrate that the design of the data acquisition system and the data processing procedure can generate dense and fully colored point clouds of indoor environments successfully even in featureless areas. The accuracy of the generated point clouds were evaluated by comparing the widths and heights of identified objects as well as coordinates of pre-set independent check points against in situ measurements. Based on the generated point clouds, complete and accurate three-dimensional models of indoor environments can be constructed effectively.

  13. CIMIDx: Prototype for a Cloud-Based System to Support Intelligent Medical Image Diagnosis With Efficiency

    PubMed Central

    2015-01-01

    Background The Internet has greatly enhanced health care, helping patients stay up-to-date on medical issues and general knowledge. Many cancer patients use the Internet for cancer diagnosis and related information. Recently, cloud computing has emerged as a new way of delivering health services but currently, there is no generic and fully automated cloud-based self-management intervention for breast cancer patients, as practical guidelines are lacking. Objective We investigated the prevalence and predictors of cloud use for medical diagnosis among women with breast cancer to gain insight into meaningful usage parameters to evaluate the use of generic, fully automated cloud-based self-intervention, by assessing how breast cancer survivors use a generic self-management model. The goal of this study was implemented and evaluated with a new prototype called “CIMIDx”, based on representative association rules that support the diagnosis of medical images (mammograms). Methods The proposed Cloud-Based System Support Intelligent Medical Image Diagnosis (CIMIDx) prototype includes two modules. The first is the design and development of the CIMIDx training and test cloud services. Deployed in the cloud, the prototype can be used for diagnosis and screening mammography by assessing the cancers detected, tumor sizes, histology, and stage of classification accuracy. To analyze the prototype’s classification accuracy, we conducted an experiment with data provided by clients. Second, by monitoring cloud server requests, the CIMIDx usage statistics were recorded for the cloud-based self-intervention groups. We conducted an evaluation of the CIMIDx cloud service usage, in which browsing functionalities were evaluated from the end-user’s perspective. Results We performed several experiments to validate the CIMIDx prototype for breast health issues. The first set of experiments evaluated the diagnostic performance of the CIMIDx framework. We collected medical information from 150 breast cancer survivors from hospitals and health centers. The CIMIDx prototype achieved high sensitivity of up to 99.29%, and accuracy of up to 98%. The second set of experiments evaluated CIMIDx use for breast health issues, using t tests and Pearson chi-square tests to assess differences, and binary logistic regression to estimate the odds ratio (OR) for the predictors’ use of CIMIDx. For the prototype usage statistics for the same 150 breast cancer survivors, we interviewed 114 (76.0%), through self-report questionnaires from CIMIDx blogs. The frequency of log-ins/person ranged from 0 to 30, total duration/person from 0 to 1500 minutes (25 hours). The 114 participants continued logging in to all phases, resulting in an intervention adherence rate of 44.3% (95% CI 33.2-55.9). The overall performance of the prototype for the good category, reported usefulness of the prototype (P=.77), overall satisfaction of the prototype (P=.31), ease of navigation (P=.89), user friendliness evaluation (P=.31), and overall satisfaction (P=.31). Positive evaluations given by 100 participants via a Web-based questionnaire supported our hypothesis. Conclusions The present study shows that women felt favorably about the use of a generic fully automated cloud-based self- management prototype. The study also demonstrated that the CIMIDx prototype resulted in the detection of more cancers in screening and diagnosing patients, with an increased accuracy rate. PMID:25830608

  14. Branching patterns of the male internal iliac artery: imaging findings.

    PubMed

    Bilhim, Tiago; Casal, Diogo; Furtado, Andrea; Pais, Diogo; O'Neill, João Erse Goyri; Pisco, João Martins

    2011-03-01

    The aim of this study was to establish the imaging findings of the main branching patterns of the male internal iliac arteries, using different imaging modalities (angio MR, angio CT and digital angiography). Twenty-one males (mean age 73.2 years) underwent imaging evaluation with angio MR, angio CT and digital angiography to define the internal iliac artery anatomy before selective embolization of the pelvic arteries. All three modalities were used in 3 patients, angio MR and digital angiography in 17 patients, angio CT and digital angiography in 6 patients and only angio CT in 1 patient. Internal iliac arteries were classified into four groups using the Yamaki classification (modified from the Adachi's classification). Twenty-six pelvic sides were classified as Group A (61.9%), 13 as Group B (31%) and 3 as Group C (7.1%) with no cases of Group D found. Angio MR, angio CT and digital angiography were able to detect most branches of the internal iliac artery. Group A was the most frequent internal iliac artery branching pattern. Angio CT showed better detailed anatomy than angio MR and digital angiography was considered the gold-standard. Non-invasive vascular imaging with angio MR or angio CT is essential before invasive interventions, allowing better planning of the procedure. PMID:20798937

  15. Hubble space telescope imaging of decoupled dust clouds in the ram pressure stripped Virgo spirals NGC 4402 and NGC 4522

    SciTech Connect

    Abramson, Anne; Kenney, Jeffrey D. P. E-mail: jeff.kenney@yale.edu

    2014-03-01

    We present the highest-resolution study to date of the interstellar medium (ISM) in galaxies undergoing ram pressure stripping, using Hubble Space Telescope BVI imaging of NGC 4522 and NGC 4402, Virgo Cluster spirals that are well known to be experiencing intracluster medium (ICM) ram pressure. We find that throughout most of both galaxies, the main dust lane has a fairly well-defined edge, with a population of giant molecular cloud (GMC) sized (tens- to hundreds-of-pc scale), isolated, highly extincting dust clouds located up to ∼1.5 kpc radially beyond it. Outside of these dense clouds, the area has little or no diffuse dust extinction, indicating that the clouds have decoupled from the lower-density ISM material that has already been stripped. Several of the dust clouds have elongated morphologies that indicate active ram pressure, including two large (kpc scale) filaments in NGC 4402 that are elongated in the projected ICM wind direction. We calculate a lower limit on the H I + H{sub 2} masses of these clouds based on their dust extinctions and find that a correction factor of ∼10 gives cloud masses consistent with those measured in CO for clouds of similar diameters, probably due to the complicating factors of foreground light, cloud substructure, and resolution limitations. Assuming that the clouds' actual masses are consistent with those of GMCs of similar diameters (∼10{sup 4}-10{sup 5} M {sub ☉}), we estimate that only a small fraction (∼1%-10%) of the original H I + H{sub 2} remains in the parts of the disks with decoupled clouds. Based on Hα images, a similar fraction of star formation persists in these regions, 2%-3% of the estimated pre-stripping star formation rate. We find that the decoupled cloud lifetimes may be up to 150-200 Myr.

  16. Imaging of Turbulent Mode Patterns in the Magnetic Reconnection Experiment

    NASA Astrophysics Data System (ADS)

    Trintchouk, F.; Yamada, M.; Ji, H.; Carter, T.; Levinton, F. M.

    2001-05-01

    Turbulent plasma motions have been observed to accompany the process of magnetic reconnection in the Magnetic Reconnection Experiment. Probe measurement shows large amplitude fluctuations with broad spectrum to be present during reconnection. These fluctuations may contain a clue to the nature of the anomalous resistivity responsible for the fast non-classical reconnection of the magnetospheric and coronal magnetic fields. However, the identification of the nature of the instability and its propagation properties with probes is made extremely complicated due to the lack of data on the orientation of the three-dimensional wavevector. The Planar Laser-Induced Fluorescence (PLIF) Imaging technique provides a possibility to obtain 2-dimensional images of metastable ion density with high spatial resolution with exposure times of a fraction of the characteristic time scale of the fluctuations of interest. Equilibrium profiles of the ion density obtained with PLIF in MRX are compared to probe data and theoretical Harris equilibrium. PLIF image pairs obtained with a two-frame capable imager allow background emission subtraction and are expected to achieve theoretical photon-statistics-limited noise performance. The images will reveal the mode patterns of the density fluctuations. By showing turbulent wavefronts in 2D the PLIF images will provide wavenumber information in unprecedented detail and at least partially remove the uncertainty in the propagation measurement by probes.

  17. Ice Cloud Optical and Microphysical Properties from the CALIPSO Imaging Infrared Radiometer

    NASA Astrophysics Data System (ADS)

    Garnier, A.; Pelon, J.; Dubuisson, P.; Yang, P.; Vaughan, M.; Avery, M. A.; Winker, D. M.

    2013-12-01

    We will present cirrus cloud optical and microphysical properties as retrieved from the operational analysis of the Imaging Infrared Radiometer (IIR) data in synergy with the CALIOP lidar co-located observations collected in the framework of the CALIPSO mission. The IIR data provides nighttime and daytime independent retrievals of optical depth and effective diameter, from which the cloud layer ice water path is inferred. The technique takes advantage of the vertical information provided by CALIOP to select suitable scenes and compute effective emissivity and optical depth. Effective diameters are retrieved through microphysical indices defined as the ratio of the effective infrared optical depths in the two pairs of channels 10.6-12.05 ?m and 8.65-12.05 ?m, and are related to the ice crystal effective diameter and shape through pre-computed Look-Up Tables. Sources of uncertainty are discussed and possible biases are assessed through internal consistency checks. Comparisons of IIR and CALIOP cirrus optical depths show the very good sensitivity of the IIR retrievals, down to 0.05 visible optical depth. It is shown that particle effective diameter and cloud layer ice water path of single-layered cirrus clouds can be retrieved over ocean, land, as well as over low opaque clouds, for thin to dense clouds of visible optical depth ranging between 0.1 and 6 and of ice water path found typically between 1 and 150 g.m-2. Taking advantage of the cloud boundaries simultaneously derived by CALIOP, IIR power law relationships between mean ice water content (IWC, in g.m-3) and mean extinction coefficient (?, in m-1) are established for cloud temperatures between 190 and 233 K. An average global power law relationship IWC = 75. ?1.23 is obtained, which compares well with parameterizations derived from in-situ observations at mid-latitude and in the tropics. However, the IWCs reported in our study are lower by about 40% than those derived from the power law relationship used in the CALIOP Version 3 algorithm. The IIR and CALIOP Level 2 operational products (currently Version 3) are publicly available at NASA Langley ASDC and ICARE data center.

  18. Design and characterization of specMACS, a multipurpose hyperspectral cloud and sky imager

    NASA Astrophysics Data System (ADS)

    Ewald, F.; Klling, T.; Baumgartner, A.; Zinner, T.; Mayer, B.

    2015-09-01

    The new spectrometer of the Munich Aerosol Cloud Scanner (specMACS) is a multipurpose hyperspectral cloud and sky imager designated, but not limited to investigations of cloud-aerosol interactions in Earth's atmosphere. Equipped with a high spectral and spatial resolution, the instrument is designed to measure solar radiation in the visible and short-wave infrared region that is reflected from, or transmitted through clouds and aerosol layers. It is based on two hyperspectral line cameras that measure in the solar spectral range between 400-2500 nm with a spectral bandwidth between 2.5-12.0 nm. The instrument was already operated in ground-based campaigns as well as aboard the German High Altitude LOng Range (HALO) research aircraft, e.g. during the ACRIDICON-CHUVA campaign in Brazil during summer 2014. This paper describes the specMACS instrument hardware and software design and characterizes the instrument performance. During the laboratory characterization of the instrument the radiometric response as well as the spatial and spectral performance was assessed. Since the instrument is primarily intended for retrievals of atmospheric quantities by inversion of radiative models using measured radiances, a focus is placed on the determination of its radiometric response. Radiometric characterization was possible for both spectrometers with an absolute accuracy of 3 % at their respective central wavelength regions. First measurements are presented which demonstrate the application possibilities and show that the key demands on radiometric and spectral accuracy as posed by the intended remote sensing techniques are fulfilled.

  19. Automatic Detection of Building Points from LIDAR and Dense Image Matching Point Clouds

    NASA Astrophysics Data System (ADS)

    Maltezos, E.; Ioannidis, C.

    2015-08-01

    This study aims to detect automatically building points: (a) from LIDAR point cloud using simple techniques of filtering that enhance the geometric properties of each point, and (b) from a point cloud which is extracted applying dense image matching at high resolution colour-infrared (CIR) digital aerial imagery using the stereo method semi-global matching (SGM). At first step, the removal of the vegetation is carried out. At the LIDAR point cloud, two different methods are implemented and evaluated using initially the normals and the roughness values afterwards: (1) the proposed scan line smooth filtering and a thresholding process, and (2) a bilateral filtering and a thresholding process. For the case of the CIR point cloud, a variation of the normalized differential vegetation index (NDVI) is computed for the same purpose. Afterwards, the bare-earth is extracted using a morphological operator and removed from the rest scene so as to maintain the buildings points. The results of the extracted buildings applying each approach at an urban area in northern Greece are evaluated using an existing orthoimage as reference; also, the results are compared with the corresponding classified buildings extracted from two commercial software. Finally, in order to verify the utility and functionality of the extracted buildings points that achieved the best accuracy, the 3D models in terms of Level of Detail 1 (LoD 1) and a 3D building change detection process are indicatively performed on a sub-region of the overall scene.

  20. Security authentication using the reflective glass pattern imaging effect.

    PubMed

    Zhu, Ji Cheng; Shen, Su; Wu, Jian Hong

    2015-11-01

    The reflective glass pattern imaging effect is investigated experimentally for the utility in forming a synthetic 3D image as a security authentication device in this Letter. An array of homogeneously randomly distributed reflective elements and a corresponding micropattern array are integrated onto a thin layer of polyester film aiming to create a vivid image floating over a substrate surface, which can be clearly visible to the naked eye. By using the reflective-type configuration, the micro-optic system can be realized on a thinner substrate and is immune to external stain due to its flat working plane. A novel gravure-like doctor blading technique can realize a resolution up to 12,000 dpi and a stringent 2D alignment requirement should be imposed. Such devices can find applications in document security and banknotes or other valuable items to protect them against forgery. PMID:26512494

  1. Synergistic combination of clinical and imaging features predicts abnormal imaging patterns of pulmonary infections.

    PubMed

    Bagci, Ulas; Jaster-Miller, Kirsten; Olivier, Kenneth N; Yao, Jianhua; Mollura, Daniel J

    2013-09-01

    We designed and tested a novel hybrid statistical model that accepts radiologic image features and clinical variables, and integrates this information in order to automatically predict abnormalities in chest computed-tomography (CT) scans and identify potentially important infectious disease biomarkers. In 200 patients, 160 with various pulmonary infections and 40 healthy controls, we extracted 34 clinical variables from laboratory tests and 25 textural features from CT images. From the CT scans, pleural effusion (PE), linear opacity (or thickening) (LT), tree-in-bud (TIB), pulmonary nodules, ground glass opacity (GGO), and consolidation abnormality patterns were analyzed and predicted through clinical, textural (imaging), or combined attributes. The presence and severity of each abnormality pattern was validated by visual analysis of the CT scans. The proposed biomarker identification system included two important steps: (i) a coarse identification of an abnormal imaging pattern by adaptively selected features (AmRMR), and (ii) a fine selection of the most important features from the previous step, and assigning them as biomarkers, depending on the prediction accuracy. Selected biomarkers were used to classify normal and abnormal patterns by using a boosted decision tree (BDT) classifier. For all abnormal imaging patterns, an average prediction accuracy of 76.15% was obtained. Experimental results demonstrated that our proposed biomarker identification approach is promising and may advance the data processing in clinical pulmonary infection research and diagnostic techniques. PMID:23930819

  2. Proceedings of the Second Annual Symposium on Mathematical Pattern Recognition and Image Analysis Program

    NASA Technical Reports Server (NTRS)

    Guseman, L. F., Jr. (Principal Investigator)

    1984-01-01

    Several papers addressing image analysis and pattern recognition techniques for satellite imagery are presented. Texture classification, image rectification and registration, spatial parameter estimation, and surface fitting are discussed.

  3. Multi Spectral Pushbroom Imaging Radiometer (MPIR) for remote sensing cloud studies

    SciTech Connect

    Phipps, G.S.; Grotbeck, C.L.

    1995-10-01

    A Multi Spectral Pushbroom Imaging Radiometer (MPIR) has been developed as are relatively inexpensive ({approximately}$IM/copy), well-calibrated,imaging radiometer for aircraft studies of cloud properties. The instrument is designed to fly on an Unmanned Aerospace Vehicle (UAV) platform at altitudes from the surface up to 20 km. MPIR is being developed to support the Unmanned Aerospace Vehicle portion of the Department of Energy`s Atmospheric Radiation Measurements program (ARM/UAV). Radiation-cloud interactions are the dominant uncertainty in the current General Circulation Models used for atmospheric climate studies. Reduction of this uncertainty is a top scientific priority of the US Global Change Research Program and the ARM program. While the DOE`s ARM program measures a num-ber of parameters from the ground-based Clouds and Radiation Testbed sites, it was recognized from the outset that other key parameters are best measured by sustained airborne data taking. These measurements are critical in our understanding of global change issues as well as for improved atmospheric and near space weather forecasting applications.

  4. Monthly and Seasonal Cloud Cover Patterns at the Manila Observatory (14.64°N, 121.08°E)

    NASA Astrophysics Data System (ADS)

    Antioquia, C. T.; Lagrosas, N.; Caballa, K.

    2014-12-01

    A ground based sky imaging system was developed at the Manila Observatory in 2012 to measure cloud occurrence and to analyse seasonal variation of cloud cover over Metro Manila. Ground-based cloud occurrence measurements provide more reliable results compared to satellite observations. Also, cloud occurrence data aid in the analysis of radiation budget in the atmosphere. In this study, a GoPro Hero 2 with almost 180o field of view is employed to take pictures of the atmosphere. These pictures are taken continuously, having a temporal resolution of 1min. Atmospheric images from April 2012 to June 2013 (excluding the months of September, October, and November 2012) were processed to determine cloud cover. Cloud cover in an image is measured as the ratio of the number of pixels with clouds present in them to the total number of pixels. The cloud cover values were then averaged over each month to know its monthly and seasonal variation. In Metro Manila, the dry season occurs in the months of November to May of the next year, while the wet season occurs in the months of June to October of the same year. Fig 1 shows the measured monthly variation of cloud cover. No data was collected during the months of September (wherein the camera was used for the 7SEAS field campaign), October, and November 2012 (due to maintenance and repairs). Results show that there is high cloud cover during the wet season months (80% on average) while there is low cloud cover during the dry season months (62% on average). The lowest average cloud cover for a wet season month occurred in June 2012 (73%) while the highest average cloud cover for a wet season month occurred in June 2013 (86%). The variations in cloud cover average in this season is relatively smaller compared to that of the dry season wherein the lowest average cloud cover in a month was during April 2012 (38%) while the highest average cloud cover in a month was during January 2013 (77%); minimum and maximum averages being 39% apart. During the wet season, the cloud occurrence is mainly due to tropical storms, Southwest Monsoon, and local convection processes. In the dry season, less cloud is formed because of cold dry air from Northeast Monsoon (December to February) and generally dry and hot weather (March to May). Regular data collection has been implemented for further long term data analysis.

  5. Spatial distribution of jovian clouds, hazes and colors from Cassini ISS multi-spectral images

    NASA Astrophysics Data System (ADS)

    Ordonez-Etxeberria, I.; Hueso, R.; Sánchez-Lavega, A.; Pérez-Hoyos, S.

    2016-03-01

    The Cassini spacecraft made a gravity assist flyby of Jupiter in December 2000. The Imaging Science Subsystem (ISS) acquired images of the planet that covered the visual range with filters sensitive to the distribution of clouds and hazes, their altitudes and color. We use a selection of these images to build high-resolution cylindrical maps of the planet in 9 wavelengths. We explore the spatial distribution of the planet reflectivity examining the distribution of color and altitudes of hazes as well as their relation. A variety of analyses is presented: (a) Principal Component Analysis (PCA); (b) color-altitude indices; and (c) chromaticity diagrams (for a quantitative characterization of Jupiter "true" colors as they would be perceived by a human observer). PCA of the full dataset indicates that six components are required to explain the data. These components are likely related to the distribution of cloud opacity at the main cloud, the distribution of two types of hazes, two chromophores or coloring processes and the distribution of convective storms. While the distribution of a single chromophore can explain most of the color variations in the atmosphere, a second coloring agent is required to explain the brownish cyclones in the North Equatorial Belt (NEB). This second colorant could be caused by a different chromophore or by the same chromophore located in structures deeper in the atmosphere. Color indices separate different dynamical regions where cloud color and altitude are correlated from those where they are not. The Great Red Spot (GRS) appears as a well separated region in terms of its position in a global color-altitude scatter diagram and different families of vortices are examined, including the red cyclones which are located deeper in the atmosphere. Finally, a chromaticity diagram of Jupiter nearly true color images quantifies the color variations in Jupiter's clouds from the perspective of a visual observer and helps to quantify how different are the observed shades of yellow and red. The color analysis also gives additional evidence in favor of a second distinct color in the red brown cyclones of the NEB.

  6. Robust image region descriptor using local derivative ordinal binary pattern

    NASA Astrophysics Data System (ADS)

    Shang, Jun; Chen, Chuanbo; Pei, Xiaobing; Liang, Hu; Tang, He; Sarem, Mudar

    2015-05-01

    Binary image descriptors have received a lot of attention in recent years, since they provide numerous advantages, such as low memory footprint and efficient matching strategy. However, they utilize intermediate representations and are generally less discriminative than floating-point descriptors. We propose an image region descriptor, namely local derivative ordinal binary pattern, for object recognition and image categorization. In order to preserve more local contrast and edge information, we quantize the intensity differences between the central pixels and their neighbors of the detected local affine covariant regions in an adaptive way. These differences are then sorted and mapped into binary codes and histogrammed with a weight of the sum of the absolute value of the differences. Furthermore, the gray level of the central pixel is quantized to further improve the discriminative ability. Finally, we combine them to form a joint histogram to represent the features of the image. We observe that our descriptor preserves more local brightness and edge information than traditional binary descriptors. Also, our descriptor is robust to rotation, illumination variations, and other geometric transformations. We conduct extensive experiments on the standard ETHZ and Kentucky datasets for object recognition and PASCAL for image classification. The experimental results show that our descriptor outperforms existing state-of-the-art methods.

  7. On dictionary adaptation for recurrent pattern image coding.

    PubMed

    Rodrigues, Nuno M M; da Silva, Eduardo A B; de Carvalho, Murilo B; de Faria, Sérgio M M; da Silva, Vitor M M

    2008-09-01

    In this paper, we exploit a recently introduced coding algorithm called multidimensional multiscale parser (MMP) as an alternative to the traditional transform quantization-based methods. MMP uses approximate pattern matching with adaptive multiscale dictionaries that contain concatenations of scaled versions of previously encoded image blocks. We propose the use of predictive coding schemes that modify the source's probability distribution, in order to favour the efficiency of MMP's dictionary adaptation. Statistical conditioning is also used, allowing for an increased coding efficiency of the dictionaries' symbols. New dictionary design methods, that allow for an effective compromise between the introduction of new dictionary elements and the reduction of codebook redundancy, are also proposed. Experimental results validate the proposed techniques by showing consistent improvements in PSNR performance over the original MMP algorithm. When compared with state-of-the-art methods, like JPEG2000 and H.264/AVC, the proposed algorithm achieves relevant gains (up to 6 dB) for nonsmooth images and very competitive results for smooth images. These results strongly suggest that the new paradigm posed by MMP can be regarded as an alternative to the one traditionally used in image coding, for a wide range of image types. PMID:18701400

  8. Graphene electrically reconfigurable patterns for THz imaging applications

    NASA Astrophysics Data System (ADS)

    Sensale-Rodriguez, Berardi; Rafique, Subrina; Yan, Rusen; Zhu, Mingda; Protasenko, Vladimir; Jena, Debdeep; Liu, Lei; Xing, Huili Grace

    2013-03-01

    THz waves are attractive for several imaging applications, since they can propagate through non metallic media such as paper, cloth, plastics, and ceramics, and do not scatter over nano-scale defects or ionize the material under imaging -as might shorter wavelengths do- while offering an image resolution similar to that of the human eye. In this work we propose and experimentally demonstrate electrically reconfigurable patterns for single-pixel terahertz imaging based on arrays of graphene THz electro-absorption modulators. In an optical setup, in conjunction with mirrors, the modulator array can transform the output radiation from a CW THz source into a pixelated and collimated beam of illumination. Single-atom-thick graphene is employed as the active element of these modulators, achieving a modulation of the THz wave reflectance >50% with a potential modulation depth approaching 100% (i.e. each region of the pixelated collimated beam can be potentially completely turned-off). Although the proof-of-concept device here discussed only consists of 4x4 elements, we foresee that this technology can enable low-cost video rate THz imaging systems.

  9. Micro-patterned quantum dots excitation for cellular microarray imaging

    NASA Astrophysics Data System (ADS)

    Bhave, Gauri; Ng, Elaine; Lee, Youngkyu; Zhang, John X.

    2015-03-01

    We present a compact light source designed for arrayed lab-on-chip cell imaging with the motivation of creating a microchip based system for detection of tumor cells. We aim at creating a multicolor light source that can be integrated for on-chip imaging. Colloidal quantum dots (QDs) were used as the emission layer due to their unique capabilities like multicolor emission, multiple available methods of electrical and photo excitation and compatibility with silicon fabrication were achieved. Micropatterning of QDs was used to create both electrically and photo excited light sources. We study the photo activated source as a robust, high intensity light source which can be easily integrated with lab-onchip systems while requiring additional filters and excitation systems and compare it with an electrically excited source with the capability of individually addressable, multicolor sources on a single substrate eliminating the need for additional optical components. To demonstrate the efficacy of our design, we performed ex vivo transmission mode microscopy to evaluate the nucleus-cytoplasm ratios of cancer cells. We showed the capability of imaging of inner cell structures using multiple wavelengths to perform high contrast imaging and observation. We performed immunofluorescence excitation of MDA-MB 231 cancer cells, cultured in a microwell array. Our method provides patterned multicolor light sources and low cost which are suitable for high-throughput microarray cellular imaging.

  10. Functional imaging patterns in Alzheimer's disease. Relationships to neurobiology.

    PubMed

    Jagust, W J

    1996-01-17

    Brain imaging with functional techniques, such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) have been widely applied to the study of dementia. While the pattern of temporal and parietal hypometabolism and hypoperfusion have often been suggested to be of diagnostic utility in ascertaining that a dementia is due to Alzheimer's disease (AD), the exact sensitivity and specificity of this pattern in clinically important situations is unclear. These imaging findings have been of considerable interest, however, in describing the regional patterns of predilection in the disease. Evidence supports the contention that the earliest sites of functional impairment in AD are in the temporal lobes. Surprisingly, however, mesial temporal lobe hypometabolism was difficult to detect in a group of mildly demented AD patients in comparison to a group of healthy older subjects. These results suggest that simple use of mesial temporal lobe metabolic rates as a diagnostic for AD may not be fruitful, and that evaluation of the earliest stages of AD can be most productively studied by investigating healthy older individuals. PMID:8624103

  11. Efficient method for detecting and tracking rainfall clouds in non-Doppler radar images

    NASA Astrophysics Data System (ADS)

    Raaf, Ouarda; El Hamid Adane, Abd

    2014-01-01

    The precipitation echoes collected by non-Doppler meteorological radar are identified and tracked in the covered area. For that a sequence of images, recorded every 5 min by S-band radar in Bordeaux and previously filtered to remove the ground clutter, is considered. In these images, the radar echoes are labeled as precipitation cells and processed using the method of sum and difference histograms of gray levels. Textural parameters are extracted from these images by slicing an analysis window of 55 pixels. Energy and homogeneity are found to be the best discriminating parameters because each of them clearly assigns the radar echoes to either stratiform or cumuliform clouds. The convective cells mainly differ from the stratiform ones by their texture and the high values of their reflectivity factor. To account for the downpour development, the time variations of barycenter, surface area, and reflectivity factor have been analyzed for the precipitation cells in the sequence of radar images under consideration. In the case of cumuliform cells having reflectivity factor higher than 40 dBZ, the expansion of their surface area and their progress in the observed region constitute important information about the clouds leading to weather extremes.

  12. IMAGING OF THE CCS 22.3 GHz EMISSION IN THE TAURUS MOLECULAR CLOUD COMPLEX

    SciTech Connect

    Roy, Nirupam; Momjian, Emmanuel; Datta, Abhirup; Sarma, Anuj P.

    2011-09-20

    Thioxoethenylidene (CCS) is an abundant interstellar molecule and a good tracer of high density and evolutionary stage of dense molecular clouds. It is also a suitable candidate for Zeeman splitting observations for its high splitting factor and narrow thermal line widths. We report here Expanded Very Large Array 22.3 GHz observations of three dense molecular cores TMC-1, TMC-1C, and L1521B in the Taurus molecular cloud complex to image the CCS 2{sub 1}-1{sub 0} transition. For all three sources, the clumpy CCS emission is most likely tracing the starless cores. However, these compact structures account for only {approx}1%-13% of the integrated emission detected in single-dish observations, indicating the presence of significant large-scale diffuse emission in favorable conditions for producing CCS.

  13. Moving image analysis to the cloud: A case study with a genome-scale tomographic study

    NASA Astrophysics Data System (ADS)

    Mader, Kevin; Stampanoni, Marco

    2016-01-01

    Over the last decade, the time required to measure a terabyte of microscopic imaging data has gone from years to minutes. This shift has moved many of the challenges away from experimental design and measurement to scalable storage, organization, and analysis. As many scientists and scientific institutions lack training and competencies in these areas, major bottlenecks have arisen and led to substantial delays and gaps between measurement, understanding, and dissemination. We present in this paper a framework for analyzing large 3D datasets using cloud-based computational and storage resources. We demonstrate its applicability by showing the setup and costs associated with the analysis of a genome-scale study of bone microstructure. We then evaluate the relative advantages and disadvantages associated with local versus cloud infrastructures.

  14. Two Methods for Retrieving UV Index for All Cloud Conditions from Sky Imager Products or Total SW Radiation Measurements

    SciTech Connect

    Badosa, Jordi; Calbo, J.; McKenzie, R. L.; Liley, Ben; Gonzalez, J. A.; Forgan, B. W.; Long, Charles N.

    2014-07-01

    In the present study, we assess the cloud effects on UV Index (UVI) and total solar radiation (TR) as a function of cloud cover estimations and sunny conditions (from sky imaging products) as well as of solar zenith angle (SZA). These analyses are undertaken for a southern-hemisphere mid-latitude site where a 10-years dataset is available. It is confirmed that clouds reduce TR more than UV, in particular for obscured Sun conditions, low cloud fraction (< 60%) and large SZA (> 60). Similarly, clouds enhance TR more than UV, mainly for visible Sun conditions, large cloud fraction and large SZA. Two methods to estimate UVI are developed: 1) from sky imaging cloud cover and sunny conditions, and 2) from TR measurements. Both methods may be used in practical operational applications, although Method 2 shows overall the best performance, since TR allows accounting for cloud optical properties. The mean absolute differences of Method 2 estimations with respect to measured values are 0.17 UVI units (for 1-minute data) and 0.79 Standard Erythemal Dose (SED) units (for daily integrations). Method 1 shows less accurate results but it is still suitable to estimate UVI: mean absolute differences are 0.37 UVI units and 1.6 SED.

  15. Measurement of Aerosol and Cloud Particles with PACS and HARP Hyperangular Imaging Polarimeters

    NASA Astrophysics Data System (ADS)

    Martins, J.; Fernandez-Borda, R.; Remer, L. A.; Sparr, L.; Buczkowski, S.; Munchak, L. A.

    2013-12-01

    PACS is new hyper-angular imaging polarimeter for aeorosol and cloud measurerents designed to meet the requirements of the proposed ACE decadal survey mission. The full PACS system consists of three wide field of view (110deg cross track) telescopes covering the UV, VNIR, and SWIR spectral ranges with angular coverage between +55 deg forward to -55deg backwards. The angular density can be selected to cover up to 100 different viewing angles at selected wavelengths. PACS_VNIR is a prototype airborne instrument designed to demonstrate PACS capability by deploying just one of the three wavelength modules of the full PACS. With wavelengths at 470, 550, 675, 760 and 875nm, PACS_VNIR flew for the first time during the PODEX experiment in January/February 2013 aboard the NASA ER-2 aircraft. PACS SWIR (1.64, 1.88, 2.1, and 2.25um) is currently under construction and should be operational in the lab by Fall/2013. PACS_ UV has been fully designed, but is not yet under construction. During the PODEX flights PACS_VNIR collected data for aerosol and clouds over variable surface types including, water, vegetation, urban areas, and snow. The data is currently being calibrated, geolocated and prepared for the inversion of geophysical parameters including water cloud size distribution and aerosol microphysical parameters. The large density of angles in PACS allows for the characterization of cloudbow features in relatively high spatial resolution in a pixel to pixel basis. This avoids the need for assumptions of cloud homogeneity over any distance. The hyperangle capability also allows detailed observation of cloud ice particles, surface characterization, and optimum selection of the number of angles desired for aerosol retrievals. The aerosol and cloud retrieval algorithms under development for the retrieval of particle microphysical properties from the PACS data will be discussed in this presentation. As an extension of the PACS concept we are currently developing the HARP (Hyper-Angular Rainbow Polarimeter) Cubesat satellite funded by the NASA/ESTO/InVEST program. HARP will demonstrate the PACS concept from space and will allow for high resolution angular measurements of polarized radiances over different aerosol and cloud scenarios. The HARP concept and strategy will be presented and discussed as part of the general PACS measurement strategy.

  16. Blurred image restoration based on synergetic pattern recognition

    NASA Astrophysics Data System (ADS)

    Chen, Dingguo; Gao, Jun; Pan, Menxian; Liang, Dong

    2001-09-01

    The POCS method was original developed in 1960's. It is applied in many fields such as: image processing, signal recovery and optics. The POCS method allows us to incorporate into iteration scheme available information about the experimental data and the measurement error as well as priori constraints based on physical reasoning. It is important to note that the POCS-method doesn't lead to a unique `optimum' solution. The next step to projection is to find a optimal method within a `solution space'. Based on synergetic theory founded by Haken in 1970's, this optimal problem can be resolved by synergetic pattern recognition procedure. In our paper, we propose a synergetic pattern recognition approach to accomplish the optimal processing.

  17. Adaptive pattern-based image compression for ultra-low bandwidth weapon seeker image communication

    NASA Astrophysics Data System (ADS)

    Wei, Hai; Zabuawala, Sakina; Varadarajan, Karthik M.; Yadegar, Jacob; Yadegar, Joseph; Gray, David; McCalmont, John; Utt, James

    2009-05-01

    The effectiveness of autonomous munitions systems can be enhanced by transmitting target images to a man-in-the-loop (MITL) as the system deploys. Based on the transmitted images, the MITL could change target priorities or conduct damage assessment in real-time. One impediment to this enhancement realization is the limited bandwidth of the system data-link. In this paper, an innovative pattern-based image compression technology is presented for enabling efficient image transmission over the ultra-low bandwidth system data link, while preserving sufficient details in the decompressed images for the MITL to perform the required assessments. Based on a pattern-driven image model, our technology exploits the structural discontinuities in the image by extracting and prioritizing edge segments with their geometric and intensity profiles. Contingent on the bit budget, only the most salient segments are encoded and transmitted, therefore achieving scalable bit-streams. Simulation results corroborate the technology efficiency and establish its subjective quality superiority over JPEG/JPEG2000 as well as feasibility for real-time implementation. Successful technology demonstrations were conducted using images from surrogate seekers in an aircraft and from a captive-carry test-bed system. The developed technology has potential applications in a broad range of network-enabled weapon systems.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  19. Optical imaging of cloud-to-stratosphere/mesosphere lightning over the Amazon Basin (CS/LAB)

    NASA Technical Reports Server (NTRS)

    Sentman, Davis D.; Wescott, Eugene M.

    1995-01-01

    The purpose of the CS/LAB project was to obtain images of cloud to stratosphere lightning discharges from aboard NASA's DC-8 Airborne Laboratory while flying in the vicinity of thunderstorms over the Amazon Basin. We devised a low light level imaging package as an add-on experiment to an airborne Laboratory deployment to South America during May-June, 1993. We were not successful in obtaining the desired images during the South American deployment. However, in a follow up flight over the American Midwest during the night of July 8-9, 1993 we recorded nineteen examples of the events over intense thunderstorms. From the observations were estimated absolute brightness, terminal altitudes, flash duration, horizontal extents, emission volumes, and frequencies relative to negative and positive ground strokes.

  20. InSAR imaging of volcanic deformation over cloud-prone areas - Aleutian islands

    USGS Publications Warehouse

    Lu, Zhong

    2007-01-01

    Interferometric synthetic aperture radar (INSAR) is capable of measuring ground-surface deformation with centimeter-tosubcentimeter precision and spatial resolution of tens-of meters over a relatively large region. With its global coverage and all-weather imaging capability, INSAR is an important technique for measuring ground-surface deformation of volcanoes over cloud-prone and rainy regions such as the Aleutian Islands, where only less than 5 percent of optical imagery is usable due to inclement weather conditions. The spatial distribution of surface deformation data, derived from INSAR images, enables the construction of detailed mechanical models to enhance the study of magmatic processes. This paper reviews the basics of INSAR for volcanic deformation mapping and the INSAR studies of ten Aleutian volcanoes associated with both eruptive and noneruptive activity. These studies demonstrate that all-weather INSAR imaging can improve our understanding of how the Aleutian volcanoes work and enhance our capability to predict future eruptions and associated hazards.

  1. Quantification of air flow patterns by image processing

    NASA Astrophysics Data System (ADS)

    Van Brecht, Andres; Janssens, Koen; Berckmans, D.; Vranken, E.

    1999-09-01

    In a ventilated space, the incoming air jet and the resulting air flow pattern play key roles in the removal or supply of heat, moisture, and harmful gases from or to living organisms (man, animal, plant). In this research, two low cost image processing methods (boundary peeling and optical flow) were developed to quantify the 2-D trajectory and the deflection angle of an air jet in a ventilated room. The image processing algorithms were applied to a wide range of air jets in a laboratory test room. Based on the deflection angle of the air jet trajectory from the initial path, a distinction could be made between falling, instable or horizontal air jets.

  2. The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI): a new tool for aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Xu, F.; Garay, M. J.; Martonchik, J. V.; Rheingans, B. E.; Geier, S.; Davis, A.; Hancock, B. R.; Jovanovic, V. M.; Bull, M. A.; Capraro, K.; Chipman, R. A.; McClain, S. C.

    2013-02-01

    The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) is an eight-band (355, 380, 445, 470, 555, 660, 865, 935 nm) pushbroom camera, measuring polarization in the 470, 660, and 865 nm bands, mounted on a gimbal to acquire multiangular observations over a ± 67° along-track range. The instrument has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI employs a photoelastic modulator-based polarimetric imaging technique to enable accurate measurements of the degree and angle of linear polarization in addition to spectral intensity. A description of the AirMSPI instrument and ground data processing approach is presented. Example images of clear, hazy, and cloudy scenes over the Pacific Ocean and California land targets obtained during flights between 2010 and 2012 are shown, and quantitative interpretations of the data using vector radiative transfer theory and scene models are provided to highlight the instrument's capabilities for determining aerosol and cloud microphysical properties and cloud 3-D spatial distributions. Sensitivity to parameters such as aerosol particle size distribution, ocean surface wind speed and direction, cloud-top and cloud-base height, and cloud droplet size is discussed. AirMSPI represents a major step toward realization of the type of imaging polarimeter envisioned to fly on NASA's Aerosol-Cloud-Ecosystem (ACE) mission in the next decade.

  3. The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI): a new tool for aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Xu, F.; Garay, M. J.; Martonchik, J. V.; Rheingans, B. E.; Geier, S.; Davis, A.; Hancock, B. R.; Jovanovic, V. M.; Bull, M. A.; Capraro, K.; Chipman, R. A.; McClain, S. C.

    2013-08-01

    The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) is an eight-band (355, 380, 445, 470, 555, 660, 865, 935 nm) pushbroom camera, measuring polarization in the 470, 660, and 865 nm bands, mounted on a gimbal to acquire multiangular observations over a ±67° along-track range. The instrument has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI employs a photoelastic modulator-based polarimetric imaging technique to enable accurate measurements of the degree and angle of linear polarization in addition to spectral intensity. A description of the AirMSPI instrument and ground data processing approach is presented. Example images of clear, hazy, and cloudy scenes over the Pacific Ocean and California land targets obtained during flights between 2010 and 2012 are shown, and quantitative interpretations of the data using vector radiative transfer theory and scene models are provided to highlight the instrument's capabilities for determining aerosol and cloud microphysical properties and cloud 3-D spatial distributions. Sensitivity to parameters such as aerosol particle size distribution, ocean surface wind speed and direction, cloud-top and cloud-base height, and cloud droplet size is discussed. AirMSPI represents a major step toward realization of the type of imaging polarimeter envisioned to fly on NASA's Aerosol-Cloud-Ecosystem (ACE) mission in the next decade.

  4. Segmentation of interstitial lung disease patterns in HRCT images

    NASA Astrophysics Data System (ADS)

    Dash, Jatindra K.; Madhavi, Vaddepalli; Mukhopadhyay, Sudipta; Khandelwal, Niranjan; Kumar, Prafulla

    2015-03-01

    Automated segmentation of pathological bearing region is the first step towards the development of lung CAD. Most of the work reported in the literature related to automated analysis of lung tissue aims towards classification of fixed sized block into one of the classes. This block level classification of lung tissues in the image never results in accurate or smooth boundaries between different regions. In this work, effort is taken to investigate the performance of three automated image segmentation algorithms those results in smooth boundaries among lung tissue patterns commonly encountered in HRCT images of the thorax. A public database that consists of HRCT images taken from patients affected with Interstitial Lung Diseases (ILDs) is used for the evaluation. The algorithms considered are Markov Random Field (MRF), Gaussian Mixture Model (GMM) and Mean Shift (MS). 2-fold cross validation approach is followed for the selection of the best parameter value for individual algorithm as well as to evaluate the performance of all the algorithms. Mean shift algorithm is observed as the best performer in terms of Jaccard Index, Modified Hausdorff Distance, accuracy, Dice Similarity Coefficient and execution speed.

  5. Feature extraction from 3D lidar point clouds using image processing methods

    NASA Astrophysics Data System (ADS)

    Zhu, Ling; Shortridge, Ashton; Lusch, David; Shi, Ruoming

    2011-10-01

    Airborne LiDAR data have become cost-effective to produce at local and regional scales across the United States and internationally. These data are typically collected and processed into surface data products by contractors for state and local communities. Current algorithms for advanced processing of LiDAR point cloud data are normally implemented in specialized, expensive software that is not available for many users, and these users are therefore unable to experiment with the LiDAR point cloud data directly for extracting desired feature classes. The objective of this research is to identify and assess automated, readily implementable GIS procedures to extract features like buildings, vegetated areas, parking lots and roads from LiDAR data using standard image processing tools, as such tools are relatively mature with many effective classification methods. The final procedure adopted employs four distinct stages. First, interpolation is used to transfer the 3D points to a high-resolution raster. Raster grids of both height and intensity are generated. Second, multiple raster maps - a normalized surface model (nDSM), difference of returns, slope, and the LiDAR intensity map - are conflated to generate a multi-channel image. Third, a feature space of this image is created. Finally, supervised classification on the feature space is implemented. The approach is demonstrated in both a conceptual model and on a complex real-world case study, and its strengths and limitations are addressed.

  6. A geometric photography model for determining cloud top heights using MISR images

    NASA Astrophysics Data System (ADS)

    He, Yongjian; Qiu, Xinfa; Sun, Zhian; Li, Qiang

    2015-10-01

    Cloud top height (CTH) is an important factor in weather forecasting and monitoring. An accurate CTH has scientific significance for improving the quality of both weather analyses and numerical weather prediction. The three-dimensional geometric method has been widely recognized as a CTH calculation method that provides relatively high accuracy. In this paper, we used the theory of digital photogrammetry and remote sensing technology to establish a geometric photography model (GPM) that can simultaneously determine CTHs and cloud movement speed (CMS) by introducing the CMS into the collinearity equation of photogrammetry. The CTH is derived by constructing three-dimensional image pairs of multitemporal Multiangle Imaging Spectroradiometer (MISR) red spectral band images from three angles. Compared with CTHs observed by ground-based lidar at the United States Southern Great Plains, the difference of CTHs using the GPM relative to the reference value was less than 300 m. By analyzing the ground control points, the GPM error is estimated to be approximately 300 m. Compared with MISR CTH data, the CTHs calculated in this study were similar to that of MISR without wind.

  7. Parallel High Resolution Imaging of Diffuse Objects in the Magellanic Clouds - Cycle 3 High

    NASA Astrophysics Data System (ADS)

    Walsh, Jeremy

    1992-06-01

    The Magellanic Clouds, because of their well-determined distance and small extinction, allow an unprecedented opportunity to observe many ISM phenomena occurring in a whole galaxy. The HST resolution (0.1" = 0.025 pc) offers detail hitherto poorly studied in the extragalactic context on the morphology and spatial relationships in various ISM processes associated with the evolution of Population I and Population II systems. This long term (13 yr) parallel program exploits these opportunities by obtaining WF/PC images of appropriate targets that are accessible at the same time as primary pointings. The number of parallel observations per Cycle is estimated at ~20; and our intent is to accumulate a significant archive of Magellanic Cloud direct images over the life of the program. The parallel targets, to be specified in Phase II of each HST Cycle, will include (or search for) compact H II regions, proto-stellar and maser regions, reflection nebulae, Herbig-Haro objects, stellar ejecta, SNR and wind-driven shells, supershells, planetary nebulae, Very Low Excitation nebulae and candidates for proto-planetary nebulae. The observations will be primarily in the Balmer lines and the stronger forbidden lines, with supplemental continuum images as required.

  8. Parallel High Resolution Imaging of Diffuse Objects in the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Walsh, Jeremy

    1991-07-01

    The Magellanic Clouds, because of their well-determined distance and small extinction, allow an unprecedented opportunity to observe many ISM phenomena occurring in a whole galaxy. The HST resolution (0.1" = 0.025 pc) offers detail hitherto poorly studied in the extragalactic context on the morphology and spatial relationships in various ISM processes associated with the evolution of Population I systems. This long term (13 yr) parallel program exploits these opportunities by obtaining WF/PC images of appropriate targets that are accessible at the same time as primary spectroscopic pointings. The number of parallel observations per Cycle is estimated at 50; and our intent is to accumulate a significant archive of Magellanic Cloud direct images over the life of the program. The parallel targets, to be specified in Phase II of each HST Cycle, will include (or search for) compact H II regions, proto-stellar and maser regions, reflection nebulae, Herbig-Haro objects, stellar ejecta, SNR and wind-driven shells, supershells, planetary nebulae, Very Low Excitation nebulae and candidates for proto-planetary nebulae. The observations will be primarily in the Balmer lines and the stronger forbidden lines, with supplemental continuum images as required.

  9. Parallel High Resolution Imaging of Diffuse Objects in the Magellanic Clouds - Cycle 4 High

    NASA Astrophysics Data System (ADS)

    Walsh, Jeremy

    1994-01-01

    The Magellanic Clouds, because of their well-determined distance and small extinction, allow an unprecedented opportunity to observe many ISM phenomena occurring in a whole galaxy. The HST resolution (0.1" = 0.025 pc) offers detail hitherto poorly studied in the extragalactic context on the morphology and spatial relationships in various ISM processes associated with the evolution of Population I and Population II systems. This long term (13 yr) parallel program exploits these opportunities by obtaining WF/PC images of appropriate targets that are accessible at the same time as primary pointings. The number of parallel observations per Cycle is estimated at ~20; and our intent is to accumulate a significant archive of Magellanic Cloud direct images over the life of the program. The parallel targets, to be specified in Phase II of each HST Cycle, will include (or search for) compact H II regions, proto-stellar and maser regions, reflection nebulae, Herbig-Haro objects, stellar ejecta, SNR and wind-driven shells, supershells, planetary nebulae, Very Low Excitation nebulae and candidates for proto-planetary nebulae. The observations will be primarily in the Balmer lines and the stronger forbidden lines, with supplemental continuum images as required.

  10. Parallel high resolution imaging of diffuse objects in the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Walsh, Jeremy

    1996-07-01

    The Magellanic Clouds, because of their well-determined distance and small extinction, allow an unprecedented opportunity to observe many ISM phenomena occurring in a whole galaxy. The HST resolution {0.1" = 0.025 pc} offers detail hitherto poorly studied in the extragalactic context on the morphology and spatial relationships in various ISM processes associated with the evolution of Population I and Population II systems. This long term {11 cycles} parallel program exploits these opportunities by obtaining WFPC2 images of appropriate targets that are accessible at the same time as primary pointings. The number of priority parallel observations per Cycle is estimated at 20; and our intent is to accumulate a significant archive of Magellanic Cloud direct images over the life of the program. The parallel targets, to be specified in crafting rules executed as part of the Phase II planning of each HST Cycle, will include {or search for} compact H II regions and young clusters, proto-stellar and maser regions, reflection nebulae, Herbig-Haro objects, stellar ejecta, SNR and wind-driven shells, shells, planetary nebulae and Very Low Excitation nebulae. The observations will be primarily in the Balmer lines and the stronger forbidden lines, with supplemental continuum images.

  11. Parallel high resolution imaging of diffuse objects in the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Walsh, Jeremy

    1995-07-01

    The Magellanic Clouds, because of their well-determined distance and small extinction, allow an unprecedented opportunity to observe many ISM phenomena occurring in a whole galaxy. The HST resolution {0.1" = 0.025 pc} offers detail hitherto poorly studied in the extragalactic context on the morphology and spatial relationships in various ISM processes associated with the evolution of Population I and Population II systems. This long term {11 cycles} parallel program exploits these opportunities by obtaining WFPC2 images of appropriate targets that are accessible at the same time as primary pointings. The number of parallel observations per Cycle is estimated at 15; and our intent is to accumulate a significant archive of Magellanic Cloud direct images over the life of the program. The parallel targets, to be specified in Phase II of each HST Cycle, will include {or search for} compact H II regions and young clusters, proto-stellar and maser regions, reflection nebulae, Herbig-Haro objects, stellar ejecta, SNR and wind-driven shells, supershells, planetary nebulae, Very Low Excitation nebulae and candidate proto-planetary nebulae. The observations will be primarily in the Balmer lines and the stronger forbidden lines, with supplemental continuum images.

  12. Spatial-temporal change in precipitation patterns based on the cloud model across the Wei River Basin, China

    NASA Astrophysics Data System (ADS)

    Huang, Shengzhi; Hou, Beibei; Chang, Jianxia; Huang, Qiang; Chen, Yutong

    2015-04-01

    It is of significant importance to investigate the spatial-temporal change in precipitation patterns due to its great effects on droughts, floods, soil erosion and water resource management. A complete investigation of precipitation structure and its distribution pattern based on daily precipitation covering 1960-2005 at 21 meteorological stations in the Wei River Basin has been performed. In order to comprehensively and objectively describe the changing pattern of precipitation, the cloud model is employed to quantitatively analyse the average, uniformity and stability of precipitation. Results indicate the following: (1) the occurrence of different precipitation durations exhibits a positive exponential curve with the decrease in precipitation durations, and 1-3-day events are the predominant precipitation events which have an increasing trend; (2) precipitation and its non-uniformity is increasingly reducing, while its stability increases initially then decreases; (3) mean precipitation reduces from southeast to northwest, and the precipitation of the Guanzhong Plain has a low uniformity and stability due to its location and increasingly intensifying human activities. The cloud model provides a new idea and quantitative measure for the evaluation of the uniformity and stability of precipitation.

  13. High-resolution imaging and target designation through clouds or smoke

    DOEpatents

    Perry, Michael D.

    2003-01-01

    A method and system of combining gated intensifiers and advances in solid-state, short-pulse laser technology, compact systems capable of producing high resolution (i.e., approximately less than 20 centimeters) optical images through a scattering medium such as dense clouds, fog, smoke, etc. may be achieved from air or ground based platforms. Laser target designation through a scattering medium is also enabled by utilizing a short pulse illumination laser and a relatively minor change to the detectors on laser guided munitions.

  14. Visualisation of Complex 3d City Models on Mobile Webbrowsers Using Cloud-Based Image Provisioning

    NASA Astrophysics Data System (ADS)

    Christen, M.; Nebiker, S.

    2015-08-01

    Rendering large city models with high polygon count and a vast amount of textures at interactive frame rates is a rather difficult to impossible task as it highly depends on the client hardware, which is often insufficient, even if out-of-core rendering techniques and level of detail approaches are used. Rendering complex city models on mobile devices is even more challenging. An approach of rendering and caching very large city models in the cloud using ray-tracing based image provisioning is introduced. This allows rendering large scenes efficiently, including on mobile devices. With this approach, it is possible to render cities with nearly unlimited number of polygons and textures.

  15. Development of the PACS multi-angle imaging polarimeter for cloud and aerosols retrievals

    NASA Astrophysics Data System (ADS)

    Fernandez Borda, R. A.; Martins, J.

    2013-12-01

    Passive Aerosol & Clouds Suite Polarimeter (PACS Polarimeter) belongs to a new generation of imaging multi angle polarimetric remote sensing instruments designed to provide microphysical retrieval of aerosol and cloud particles as well as the detailed characterization of the multiangular surface properties. The PACS polarimeter design is a wide field of view multispectral polarimeter, which performs an instantaneous measurement in three linear polarization channels and is able to retrieve accurate measurements of three Stokes parameters. By its design characteristics PACS is able to offer an unique angular and spatial coverage in multispectral bands. The number of angles (up to about 100) can be selected as a function of wavelength. The simultaneity of the data acquisition in the three linear polarization channels and a detailed characterization of the PACS wide FOV optics allows for the high polarimetric accuracy required for aerosol microphysical retrievals. A new calibration and characterization methodology has been developed to cover the PACS wide FOV optics and can be applied to general system. The PACS polarimeter has flown by the first time aboard the ER2 aircraft during the PODEX experiment and collected data on aerosol and clouds over multiple surface types. In this presentation, we will discuss different test cases collected during the PODEX campaign oriented to show the capabilities and potentialities of PACS VNIR polarimeter.

  16. Using Geotags to Derive Rich Tag-Clouds for Image Annotation

    NASA Astrophysics Data System (ADS)

    Joshi, Dhiraj; Luo, Jiebo; Yu, Jie; Lei, Phoury; Gallagher, Andrew

    Geotagging has become popular for many multimedia applications. In this chapter, we present an integrated and intuitive system for location-driven tag suggestion, in the form of tag-clouds, for geotagged photos. Potential tags from multiple sources are extracted and weighted. Sources include points of interest (POI) tags from a public Geographic Names Information System (GNIS) database, community tags from Flickr pictures, and personal tags shared through users' own, family, and friends' photo collections. To increase the effectiveness of GNIS POI tags, bags of place-name tags are first retrieved, clustered, and then re-ranked using a combined tf-idf and spatial distance criteria. The community tags from photos taken in the vicinity of the input geotagged photo are ranked according to distance and visual similarity to the input photo. Personal tags from other personally related photos inherently carry a significant weight due more to their high relevance than to both the generic place-name tags and community tags, and are ranked by weights that decay over time and distance differences. Finally, a rich set of the most relevant location-driven tags is presented to the user in the form of individual tag clouds under the three mentioned source categories. The tag clouds act as intuitive suggestions for tagging an input image. We also discuss quantitative and qualitative findings from a user study that we conducted. Evaluation has revealed the respective benefits of the three categories toward the effectiveness of the integrated tag suggestion system.

  17. Diffractive-imaging-based optical image encryption with simplified decryption from single diffraction pattern.

    PubMed

    Qin, Yi; Wang, Zhipeng; Gong, Qiong

    2014-07-01

    In this paper, we propose a novel method for image encryption by employing the diffraction imaging technique. This method is in principle suitable for most diffractive-imaging-based optical encryption schemes, and a typical diffractive imaging architecture using three random phase masks in the Fresnel domain is taken for an example to illustrate it. The encryption process is rather simple because only a single diffraction intensity pattern is needed to be recorded, and the decryption procedure is also correspondingly simplified. To achieve this goal, redundant data are digitally appended to the primary image before a standard encrypting procedure. The redundant data serve as a partial input plane support constraint in a phase retrieval algorithm, which is employed for completely retrieving the plaintext. Simulation results are presented to verify the validity of the proposed approach. PMID:25089966

  18. Two methods for retrieving UV index for all cloud conditions from sky imager products or total SW radiation measurements.

    PubMed

    Badosa, Jordi; Calb, Josep; Mckenzie, Richard; Liley, Ben; Gonzlez, Josep-Abel; Forgan, Bruce; Long, Charles N

    2014-01-01

    Cloud effects on UV Index (UVI) and total solar radiation (TR) as a function of cloud cover and sunny conditions (from sky images) as well as of solar zenith angle (SZA) are assessed. These analyses are undertaken for a southern-hemisphere mid-latitude site where a 10-years dataset is available. It is confirmed that clouds reduce TR more than UV, in particular for obscured Sun conditions, low cloud fraction (<60%) and large SZA (>60). Similarly, local short-time enhancement effects are stronger for TR than for UV, mainly for visible Sun conditions, large cloud fraction and large SZA. Two methods to estimate UVI are developed: (1) from sky imaging cloud cover and sunny conditions, and (2) from TR measurements. Both methods may be used in practical applications, although Method 2 shows overall the best performance, as TR allows considering cloud optical properties. The mean absolute (relative) differences of Method 2 estimations with respect to measured values are 0.17 UVI units (6.7%, for 1 min data) and 0.79 Standard Erythemal Dose (SED) units (3.9%, for daily integrations). Method 1 shows less accurate results but it is still suitable to estimate UVI: mean absolute differences are 0.37 UVI units (15%) and 1.6 SED (8.0%). PMID:24645969

  19. Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden line emission

    NASA Astrophysics Data System (ADS)

    Steiner, J. E.; Menezes, R. B.; Ricci, T. V.; Oliveira, A. S.

    2009-06-01

    Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method'. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States); the Science and Technology Facilities Council (United Kingdom); the National Research Council (Canada), CONICYT (Chile); the Australian Research Council (Australia); Ministério da Ciência e Tecnologia (Brazil) and Secretaria de Ciencia y Tecnologia (Argentina). E-mail: steiner@astro.iag.usp.br

  20. A QR code based zero-watermarking scheme for authentication of medical images in teleradiology cloud.

    PubMed

    Seenivasagam, V; Velumani, R

    2013-01-01

    Healthcare institutions adapt cloud based archiving of medical images and patient records to share them efficiently. Controlled access to these records and authentication of images must be enforced to mitigate fraudulent activities and medical errors. This paper presents a zero-watermarking scheme implemented in the composite Contourlet Transform (CT)-Singular Value Decomposition (SVD) domain for unambiguous authentication of medical images. Further, a framework is proposed for accessing patient records based on the watermarking scheme. The patient identification details and a link to patient data encoded into a Quick Response (QR) code serves as the watermark. In the proposed scheme, the medical image is not subjected to degradations due to watermarking. Patient authentication and authorized access to patient data are realized on combining a Secret Share with the Master Share constructed from invariant features of the medical image. The Hu's invariant image moments are exploited in creating the Master Share. The proposed system is evaluated with Checkmark software and is found to be robust to both geometric and non geometric attacks. PMID:23970943

  1. A QR Code Based Zero-Watermarking Scheme for Authentication of Medical Images in Teleradiology Cloud

    PubMed Central

    Seenivasagam, V.; Velumani, R.

    2013-01-01

    Healthcare institutions adapt cloud based archiving of medical images and patient records to share them efficiently. Controlled access to these records and authentication of images must be enforced to mitigate fraudulent activities and medical errors. This paper presents a zero-watermarking scheme implemented in the composite Contourlet Transform (CT)—Singular Value Decomposition (SVD) domain for unambiguous authentication of medical images. Further, a framework is proposed for accessing patient records based on the watermarking scheme. The patient identification details and a link to patient data encoded into a Quick Response (QR) code serves as the watermark. In the proposed scheme, the medical image is not subjected to degradations due to watermarking. Patient authentication and authorized access to patient data are realized on combining a Secret Share with the Master Share constructed from invariant features of the medical image. The Hu's invariant image moments are exploited in creating the Master Share. The proposed system is evaluated with Checkmark software and is found to be robust to both geometric and non geometric attacks. PMID:23970943

  2. Beyond the partial light intensity imager: Eliminating Moir patterns

    NASA Astrophysics Data System (ADS)

    Tang, Yuanhe; Liu, Qingsong; Wu, Yong; Yu, Yang; Yang, Xusan; Gao, Haiyang; Wang, Xiaolin

    2015-11-01

    A partial light intensity imager (PLII) was proposed in our previous research for enhancing the dynamic range to 2.2105 lx in strong light. Moir patterns may occur, however, since the PLII employs both a liquid crystal display (LCD) and a charge-coupled device (CCD) camera as its key devices, which can be regarded as two gratings. This research calculates the fringe widths and spectra for both the LCD and the CCD, and analyzes the relationship between the fringe width and the applied voltage on each pixel of the LCD. According to the theoretical results, we find that changing the rotational angle of the liquid crystal (LC) molecule by regulating the applied voltage is an effective method to eliminate the Moir patterns in the PLII. Based on this principle, an experiment has been designed, and the Moir patterns fringe width is alleviated from 20 pixels to10 pixels distance before and after, and the results verify the correctness of the theoretical analysis.

  3. Calibration and Laboratory Test of the Department of Energy Cloud Particle Imager

    SciTech Connect

    McFarquhar, GM; Um, J

    2012-02-17

    Calibration parameters from the Connolly et al. (2007) algorithm cannot be applied to the Department of Energy's (DOE) CPI because the DOE CPI is version 2.0. Thus, Dr. Junshik Um and Prof. Greg McFarquhar brought the DOE CPI to the University of Manchester, UK, where facilities for calibrating it were available. In addition, two other versions of CPIs (1.0 and 1.5) were available on-site at the University of Manchester so that an intercomparison of three different versions of the CPI was possible. The three CPIs (versions 1.0, 1.5, and 2.0) were calibrated by moving glass calibration beads and ice analogues of known size parallel to the object plane. The distance between the object plane and a particle, the particle's focus, its apparent maximum dimension, and a background image were measured in order to derive calibration parameters for each CPI version. The calibration parameters are used in two empirical equations that are applied to in situ CPI data to determine particle size and depth of field, and hence particle size distributions (PSDs). After the tests with the glass calibration beads to derive the calibration parameters, the three CPIs were installed at the base of the Manchester Ice Cloud Chamber and connected to air pumps that drew cloud through the sample volume. Warm liquid clouds at a temperature of 1-2 C and ice clouds at a temperature of -5 C were generated, and the resulting PSDs for each of the CPIs were determined by applying the results of each calibration.

  4. Characterizing Spatial Patterns of Cloud Cover and Fog Inundation in the Northern Channel Islands Using Satellite Datasets and Comparison to Ground Measurements

    NASA Astrophysics Data System (ADS)

    Rastogi, B.; Still, C. J.; Fischer, D. T.; Iacobellis, S. F.; Toomey, M. P.; Greer, B.; Baguskas, S. A.; Williams, P.; McEachern, K.

    2012-12-01

    Coastal forests in Mediterranean climates are frequently covered by clouds or immersed in fog. Previous studies suggest that clouds strongly modulate forest distributions as well as carbon budgets in these semi-arid environments. Both low level stratocumulus cloud cover and fog can enhance the water status of vegetation along the Californian coast and the Channel Islands by reducing solar insolation, raising relative humidity and supplying water directly to the landscape during otherwise warm and rainless summers. While summertime fog and stratus cover in California's Channel Islands can ameliorate summer drought stress and enhance soil water budgets, they have different spatial patterns. These differing spatial patterns and the resulting shifts in relative ecological importance of fog and stratus are largely unknown. The overall objective of this project was to map spatial distributions of daytime cloud cover frequency for the California Channel Islands, and to predict probabilities of surface cloud (fog) contact and immersion for these islands. Daytime cloud cover maps were generated for the Channel Islands using data from GOES satellite imagery. Cloud frequency maps were compared and found to be in agreement with solar insolation data collected at several sites on Santa Cruz and Santa Rosa islands for the summer of 2005. These cloud frequency maps were then combined with airport cloud height data and topographic data to map estimated weekly and monthly fog inundation. The fog inundation maps were then compared to fog drip data collected at several sites on the two islands. Correlation between fog inundation and fog drip accumulation enabled spatial and temporal extrapolation to understand seasonal and inter-annual variations in cloud cover frequency and fog inundation and drip. Future studies will use these cloud and fog distributions for water balance modeling and studies of plant geography and forest distributions.

  5. Algorithms for pattern recognition in images of cell cultures

    NASA Astrophysics Data System (ADS)

    Mendes, Joyce M.; Peixoto, Nathalia L.; Ramirez-Fernandez, Francisco J.

    2001-06-01

    Several applications of silicon microstructures in areas such as neurobiology and electrophysiology have been stimulating the development of microsystems with the objective of mechanical support to monitor and control several parameters in cell cultures. In this work a multi-microelectrode arrays was fabricated over a glass plate to obtain the growth of neuronal cell monitoring their behavior during cell development. To identify the neuron core and axon an approach for implementation of edge detectors algorithms associated to images is described. The necessity of efficient and reliable algorithms for image processing and interpretation is justified by its large field of applications in several areas as well as medicine, robotics, cellular biology, computational vision and pattern recognition. In this work, it is investigated the adequacy of some edge detectors algorithms such as Canny, Marr-Hildreth. Some alterations in those methods are propose to improve the identification of both cell core and axonal growth measure. We compare the operator to edge detector proposed by Canny, Marr-Hildreth operator and application of Hough Transform. For evaluation of algorithms adaptations, we developed a method for automatic cell segmentation and measurement. Our goal is to find a set of parameters defining the location of the objects to compare the original and processed images.

  6. Imaging Dot Patterns for Measuring Gossamer Space Structures

    NASA Technical Reports Server (NTRS)

    Dorrington, A. A.; Danehy, P. M.; Jones, T. W.; Pappa, R. S.; Connell, J. W.

    2005-01-01

    A paper describes a photogrammetric method for measuring the changing shape of a gossamer (membrane) structure deployed in outer space. Such a structure is typified by a solar sail comprising a transparent polymeric membrane aluminized on its Sun-facing side and coated black on the opposite side. Unlike some prior photogrammetric methods, this method does not require an artificial light source or the attachment of retroreflectors to the gossamer structure. In a basic version of the method, the membrane contains a fluorescent dye, and the front and back coats are removed in matching patterns of dots. The dye in the dots absorbs some sunlight and fluoresces at a longer wavelength in all directions, thereby enabling acquisition of high-contrast images from almost any viewing angle. The fluorescent dots are observed by one or more electronic camera(s) on the Sun side, the shade side, or both sides. Filters that pass the fluorescent light and suppress most of the solar spectrum are placed in front of the camera(s) to increase the contrast of the dots against the background. The dot image(s) in the camera(s) are digitized, then processed by use of commercially available photogrammetric software.

  7. Integration of Point Clouds Originated from Laser Scaner and Photogrammetric Images for Visualization of Complex Details of Historical Buildings

    NASA Astrophysics Data System (ADS)

    Altuntas, C.

    2015-02-01

    Three-dimensional (3D) models of historical buildings are created for documentation and virtual realization of them. Laser scanning and photogrammetry are extensively used to perform for these aims. The selection of the method that will be used in threedimensional modelling study depends on the scale and shape of the object, and also applicability of the method. Laser scanners are high cost instruments. However, the cameras are low cost instruments. The off-the-shelf cameras are used for taking the photogrammetric images. The camera is imaging the object details by carrying on hand while the laser scanner makes ground based measurement. Laser scanner collect high density spatial data in a short time from the measurement area. On the other hand, image based 3D (IB3D) measurement uses images to create 3D point cloud data. The image matching and the creation of the point cloud can be done automatically. Historical buildings include more complex details. Thus, all details cannot be measured by terrestrial laser scanner (TLS) due to the blocking the details with each others. Especially, the artefacts which have complex shapes cannot be measured in full details. They cause occlusion on the point cloud model. However it is possible to record photogrammetric images and creation IB3D point cloud for these areas. Thus the occlusion free 3D model is created by the integration of point clouds originated from the TLS and photogrammetric images. In this study, usability of laser scanning in conjunction with image based modelling for creation occlusion free three-dimensional point cloud model of historical building was evaluated. The IB3D point cloud was created in the areas that could not been measured by TLS. Then laser scanning and IB3D point clouds were integrated in the common coordinate system. The registration point clouds were performed with the iterative closest point (ICP) and georeferencing methods. Accuracy of the registration was evaluated by convergency and its standard deviations for the ICP and residuals on the control points for the georeferencing method.

  8. Mesospheric circulation at the cloud top level of Venus according to Venus Monitoring Camera images

    NASA Astrophysics Data System (ADS)

    Khatuntsev, Igor; Patsaeva, Marina; Ignatiev, Nikolay; Titov, Dmitri; Markiewicz, Wojciech; Turin, Alexander

    We present results of wind speed measurements at the cloud top level of Venus derived from manual cloud tracking in the UV (365 nm) and IR (965 nm) channels of the Venus Monitoring Camera Experiment (VMC) [1] on board the Venus Express mission. Cloud details have a maximal contrast in the UV range. More then 90 orbits have been processed. 30000 manual vectors were obtained. The period of the observations covers more than 4 venusian year. Zonal wind speed demonstrates the local solar time dependence. Possible diurnal and semidiurnal components are observed [2]. According to averaged latitude profile of winds at level of the upper clouds: -The zonal speed is slightly increasing by absolute values from 90 on the equator to 105 m/s at latitudes 47 degrees; -The period of zonal rotation has the maximum at the equator (5 earth days). It has the minimum (3 days) at altitudes 50 degrees. After minimum periods are slightly increasing toward the South pole; -The meridional speed has a value 0 on the equator, and then it is linear increasing up to 10 m/s (by absolute value) at 50 degrees latitude. "-" denotes movement from the equator to the pole. -From 50 to 80 degrees the meridional speed is again decreasing by absolute value up to 0. IR (965+10 nm) day side images can be used for wind tracking. The obtained speed of the zonal wind in the low and middle latitudes are systematically less than the wind speed derived from the UV images. The average zonal speed obtained from IR day side images in the low and average latitudes is about 65-70 m/s. The given fact can be interpreted as observation of deeper layers of mesosphere in the IR range in comparison with UV. References [1] Markiewicz W. J. et al. (2007) Planet. Space Set V55(12). P.1701-1711. [2] Moissl R., et al. (2008) J. Geophys. Res. 2008. doi:10.1029/2008JE003117. V.113.

  9. Cloud retrieval algorithm for the imaging spectro-polarimeter on board EUMETSAT Polar System - Second Generation (EPS-SG)

    NASA Astrophysics Data System (ADS)

    Kokhanovsky, Alexander; Munro, Rose

    2015-04-01

    The atmospheric remote sensing benefits a lot from the use of spectro - polarimetric imagers on board satellite platforms. Due to the movement of the spacecraft, any given scene can be observed from many directions by an imaging polarimeter. This concept has been proven with the measurements of POLDER - 1, 2, and 3 on board ADEOS and PARASOL platforms. POLDER has performed measurements of the Stokes vector (first three components) of reflected light in 16 directions at several wavelengths in the visible and near - infrared. The 3MI (Multi-viewing, Multi-channel, Multi-polarization Imaging) on board of a future (2021) EPS-SG mission is very similar to POLDER. However, the measurements are performed at more spectral channels as compared to POLDER and also at a better spatial resolution (4*4km). In particular, the measurements of the Stokes vector components (I, Q, U) of the reflected solar light are performed at the wavelengths 410, 443, 490, 555, 670, 865, 1650, and 2130nm. In addition, the intensity of reflected light is measured at 763, 765, 910, and 1370nm. The FWHM of the channel at 763nm is 10nm and it is 20 nm at other channels (except at 765nm, 865nm, 1650nm, and 2130nm, where FWHM is equal to 40nm). The imaging spectro-polarimeter enables enhanced retrievals of aerosol and cloud properties using spaceborne observations. In particular, the following parameters of clouds can be retrieved: cloud top altitude, liquid water path, the average size of particles in the clouds, and the cloud thermodynamic state. The cloud albedo, cloud optical thickness, single scattering albedo and other optical parameters of clouds can be derived as well. In this presentation we describe the cloud retrieval algorithm CROP developed at EUMETSAT for the retrievals of cloud microphysical, geometrical, and optical characteristics using 3MI observations. The retrievals are performed only for completely cloudy pixels. The measurements at channels 763 and 765nm are used to get cloud top height. It is known that the measurements in the oxygen absorption band (763nm) enable the cloud top height determination. This is due to the fact that the reflection in the oxygen A-band is lower for lower clouds due to the increased oxygen concentration in lower atmospheric layers. The cloud liquid water path and effective radius of particles in clouds is determined from the measurements in the visible (410nm) and near - infrared (1650nm). The measurements in the visible are mostly sensitive to cloud optical thickness and liquid water path. The channel at near - infrared enables the determination of the effective radius of particles in clouds because the absorption of light is more pronounced (smaller reflectance) for larger particles in the near - infrared. The retrievals are performed in two stages. On the first stage the first guess solution is obtained based on the approximate analytical solution of the radiative transfer equation. Then look-up-tables are used to derive the final cloud products.

  10. Ly-alpha imaging of dark protogalactic clouds and circumgalactic streams using z 2 quasars

    NASA Astrophysics Data System (ADS)

    Cantalupo, Sebastiano; Hennawi, Joseph F.; Arrigoni Battaia, Fabrizio; Prochaska, Jason X.; Madau, Piero

    2013-02-01

    The ionizing radiation emitted by a luminous quasar can, like a flashlight, illuminate hydrogen in its vicinity, allowing us to directly *image* dense filaments around galaxies and proto-galactic clouds, which are otherwise invisible because of negligible star formation. We propose to conduct deep narrow band Ly-alpha imaging of luminous quasars at z 2 to detect this Ly-a fluorescence from the surrounding intergalactic and circumgalactic (CGM) medium. Our team has made the first definitive detections of this effect, and we have developed radiative transfer simulations in a cosmological setting for direct end-to-end comparison to our proposed observations. This novel technique compliments decades of effort using absorption-line techniques and will provide an ideal target list for future kinematic analysis of the CGM.

  11. Contours Based Approach for Thermal Image and Terrestrial Point Cloud Registration

    NASA Astrophysics Data System (ADS)

    Bennis, A.; Bombardier, V.; Thiriet, P.; Brie, D.

    2013-07-01

    Building energetic performances strongly depend on the thermal insulation. However the performance of the insulation materials tends to decrease over time which necessitates the continuous monitoring of the building in order to detect and repair the anomalous zones. In this paper, it is proposed to couple 2D infrared images representing the surface temperature of the building with 3D point clouds acquired with Terrestrial Laser Scanner (TLS) resulting in a semi-automatic approach allowing the texturation of TLS data with infrared image of buildings. A contour-based algorithm is proposed whose main features are : 1) the extraction of high level primitive is not required 2) the use of projective transform allows to handle perspective effects 3) a point matching refinement procedure allows to cope with approximate control point selection. The procedure is applied to test modules aiming at investigating the thermal properties of material.

  12. Design a Filter to Detect and Remove Vegetation from Ultra-Cam Aerial Images' Point Cloud to Produce Automatically Digital Elevation Model

    NASA Astrophysics Data System (ADS)

    Enayati, H.; Veissy, M.; Rahimpour, F.

    2015-12-01

    Digital elevation model is one of the most important spatial information for displaying bare earth. Because of existing objects on the ground, manual editing is unavoidable. Aerial images' point clouds produced by advanced matching methods are good resources for generating DEM. In this paper, the purpose is design a filter for detect and eliminate vegetation from point clouds. For this purpose, point clouds' texture is used for finding vegetation. Texture of point clouds is segmented by Otsu method. In the next step, segmented image is added to raster of elevation and vegetation elevation is detected. Results is showing that point clouds' texture is a good data for filtering vegetation and generating DEM automatically.

  13. Image Reconstruction, Recognition, Using Image Processing, Pattern Recognition and the Hough Transform.

    NASA Astrophysics Data System (ADS)

    Seshadri, M. D.

    1992-01-01

    In this dissertation research, we have demonstrated the need for integration of various imaging methodologies, such as image reconstruction from projections, image processing, pattern and feature recognition using chain codes and the Hough transform. Further an integration of these image processing techniques have been brought about for medical imaging systems. An example of this is, classification and identification of brain scans, into normal, haemorrhaged, and lacunar infarcted brain scans. Low level processing was performed using LOG and a variation of LOG. Intermediate level processing used contour completion and chain encoding. Hough transform was used to detect any analytic shapes in the edge images. All these information were used by the data abstraction routine which also extracted information from the user, in the form of a general query. These were input into a backpropagation, which is a very popular supervised neural network. During learning process an output vector was supplied by the expert to the neural network. While performing the neural network compared the input and with the help of the weight matrix computed the output. This output was compared with the expert's opinion and a percentage deviation was calculated. In the case of brain scans this value was about 95%, when the test input vector did not vary, by more than two pixels with the training or learning input vector. A good classification of the brain scans were performed using the integrated imaging system. Identification of various organs in the abdominal region was also successful, within 90% recognition rate, depending on the noise in the image.

  14. Simplified optical image encryption approach using single diffraction pattern in diffractive-imaging-based scheme.

    PubMed

    Qin, Yi; Gong, Qiong; Wang, Zhipeng

    2014-09-01

    In previous diffractive-imaging-based optical encryption schemes, it is impossible to totally retrieve the plaintext from a single diffraction pattern. In this paper, we proposed a new method to achieve this goal. The encryption procedure can be completed by proceeding only one exposure, and the single diffraction pattern is recorded as ciphertext. For recovering the plaintext, a novel median-filtering-based phase retrieval algorithm, including two iterative cycles, has been developed. This proposal not only extremely simplifies the encryption and decryption processes, but also facilitates the storage and transmission of the ciphertext, and its effectiveness and feasibility have been demonstrated by numerical simulations. PMID:25321554

  15. Astronomy in the Cloud: Using MapReduce for Image Co-Addition

    NASA Astrophysics Data System (ADS)

    Wiley, K.; Connolly, A.; Gardner, J.; Krughoff, S.; Balazinska, M.; Howe, B.; Kwon, Y.; Bu, Y.

    2011-03-01

    In the coming decade, astronomical surveys of the sky will generate tens of terabytes of images and detect hundreds of millions of sources every night. The study of these sources will involve computation challenges such as anomaly detection and classification and moving-object tracking. Since such studies benefit from the highest-quality data, methods such as image co-addition, i.e., astrometric registration followed by per-pixel summation, will be a critical preprocessing step prior to scientific investigation. With a requirement that these images be analyzed on a nightly basis to identify moving sources such as potentially hazardous asteroids or transient objects such as supernovae, these data streams present many computational challenges. Given the quantity of data involved, the computational load of these problems can only be addressed by distributing the workload over a large number of nodes. However, the high data throughput demanded by these applications may present scalability challenges for certain storage architectures. One scalable data-processing method that has emerged in recent years is MapReduce, and in this article we focus on its popular open-source implementation called Hadoop. In the Hadoop framework, the data are partitioned among storage attached directly to worker nodes, and the processing workload is scheduled in parallel on the nodes that contain the required input data. A further motivation for using Hadoop is that it allows us to exploit cloud computing resources: i.e., platforms where Hadoop is offered as a service. We report on our experience of implementing a scalable image-processing pipeline for the SDSS imaging database using Hadoop. This multiterabyte imaging data set provides a good testbed for algorithm development, since its scope and structure approximate future surveys. First, we describe MapReduce and how we adapted image co-addition to the MapReduce framework. Then we describe a number of optimizations to our basic approach and report experimental results comparing their performance.

  16. Tip-enhanced Raman spectroscopic imaging of patterned thiol monolayers

    PubMed Central

    Stadler, Johannes; Schmid, Thomas; Opilik, Lothar; Kuhn, Phillip; Dittrich, Petra S

    2011-01-01

    Summary Full spectroscopic imaging by means of tip-enhanced Raman spectroscopy (TERS) was used to measure the distribution of two isomeric thiols (2-mercaptopyridine (2-PySH) and 4-mercaptopyridine (4-PySH)) in a self-assembled monolayer (SAM) on a gold surface. From a patterned sample created by microcontact printing, an image with full spectral information in every pixel was acquired. The spectroscopic data is in good agreement with the expected molecular distribution on the sample surface due to the microcontact printing process. Using specific marker bands at 1000 cm−1 for 2-PySH and 1100 cm−1 for 4-PySH, both isomers could be localized on the surface and semi-quantitative information was deduced from the band intensities. Even though nanometer size resolution information was not required, the large signal enhancement of TERS was employed here to detect a monolayer coverage of weakly scattering analytes that were not detectable with normal Raman spectroscopy, emphasizing the usefulness of TERS. PMID:22003457

  17. Superresolution imaging with optical fluctuation using speckle patterns illumination.

    PubMed

    Kim, MinKwan; Park, ChungHyun; Rodriguez, Christophe; Park, YongKeun; Cho, Yong-Hoon

    2015-01-01

    Superresolution fluorescence microscopy possesses an important role for the study of processes in biological cells with subdiffraction resolution. Recently, superresolution methods employing the emission properties of fluorophores have rapidly evolved due to their technical simplicity and direct applicability to existing microscopes. However, the application of these methods has been limited to samples labeled with fluorophores that can exhibit intrinsic emission properties at a restricted timescale, especially stochastic blinking. Here, we present a superresolution method that can be performed using general fluorophores, regardless of this intrinsic property. Utilizing speckle patterns illumination, temporal emission fluctuation of fluorophores is induced and controlled, from which a superresolution image can be obtained exploiting its statistical property. Using this method, we demonstrate, theoretically and experimentally, the capability to produce subdiffraction resolution images. A spatial resolution of 500?nm, 300?nm and 140?nm with 0.4, 0.5 and 1.4 NA objective lenses respectively was achieved in various samples with an enhancement factor of 1.6 compared to conventional fluorescence microscopy. PMID:26572283

  18. Superresolution imaging with optical fluctuation using speckle patterns illumination

    PubMed Central

    Kim, MinKwan; Park, ChungHyun; Rodriguez, Christophe; Park, YongKeun; Cho, Yong-Hoon

    2015-01-01

    Superresolution fluorescence microscopy possesses an important role for the study of processes in biological cells with subdiffraction resolution. Recently, superresolution methods employing the emission properties of fluorophores have rapidly evolved due to their technical simplicity and direct applicability to existing microscopes. However, the application of these methods has been limited to samples labeled with fluorophores that can exhibit intrinsic emission properties at a restricted timescale, especially stochastic blinking. Here, we present a superresolution method that can be performed using general fluorophores, regardless of this intrinsic property. Utilizing speckle patterns illumination, temporal emission fluctuation of fluorophores is induced and controlled, from which a superresolution image can be obtained exploiting its statistical property. Using this method, we demonstrate, theoretically and experimentally, the capability to produce subdiffraction resolution images. A spatial resolution of 500 nm, 300 nm and 140 nm with 0.4, 0.5 and 1.4 NA objective lenses respectively was achieved in various samples with an enhancement factor of 1.6 compared to conventional fluorescence microscopy. PMID:26572283

  19. Superresolution imaging with optical fluctuation using speckle patterns illumination

    NASA Astrophysics Data System (ADS)

    Kim, Minkwan; Park, Chunghyun; Rodriguez, Christophe; Park, Yongkeun; Cho, Yong-Hoon

    2015-11-01

    Superresolution fluorescence microscopy possesses an important role for the study of processes in biological cells with subdiffraction resolution. Recently, superresolution methods employing the emission properties of fluorophores have rapidly evolved due to their technical simplicity and direct applicability to existing microscopes. However, the application of these methods has been limited to samples labeled with fluorophores that can exhibit intrinsic emission properties at a restricted timescale, especially stochastic blinking. Here, we present a superresolution method that can be performed using general fluorophores, regardless of this intrinsic property. Utilizing speckle patterns illumination, temporal emission fluctuation of fluorophores is induced and controlled, from which a superresolution image can be obtained exploiting its statistical property. Using this method, we demonstrate, theoretically and experimentally, the capability to produce subdiffraction resolution images. A spatial resolution of 500 nm, 300 nm and 140 nm with 0.4, 0.5 and 1.4 NA objective lenses respectively was achieved in various samples with an enhancement factor of 1.6 compared to conventional fluorescence microscopy.

  20. Noctilucent Cloud Imaging and Tomography using a Suborbital Reusable Launch Vehicle

    NASA Astrophysics Data System (ADS)

    Reimuller, J. D.; Fritts, D. C.; Thomas, G. E.

    2012-12-01

    Noctilucent Clouds (NLCs) are the highest clouds in the Earth's atmosphere, residing at a mean altitude of 83 km. They have been observed since 1885 around the summer solstice and are considered to be very sensitive indicators for what is going on in the atmosphere at higher altitudes. They have been observed to both increase in brightness and frequency as well as extend to lower latitudes and it has been hypothesized that the anthropogenic causes of climatic change may be directly related to NLC presence. An experiment is currently supported through NASA's Flight Opportunities program to use a Suborbital Reusable Launch Vehicle (SRLV) to fly a manned, stabilized imager suite through an NLC layer to obtain imagery and topography data of unprecedented resolution. The campaign is targeted for July 2014 and will involve a series of flights from a high-latitude spaceport when NLC activity is observed. These data should advance our understanding of energy and momentum deposition to the upper atmosphere through enhanced observations of gravity wave perturbations, instability dynamics, and turbulent regions.

  1. Near-IR Imaging Polarimetry toward a Bright-rimmed Cloud: Magnetic Field in SFO 74

    NASA Astrophysics Data System (ADS)

    Kusune, Takayoshi; Sugitani, Koji; Miao, Jingqi; Tamura, Motohide; Sato, Yaeko; Kwon, Jungmi; Watanabe, Makoto; Nishiyama, Shogo; Nagayama, Takahiro; Sato, Shuji

    2015-01-01

    We have made near-infrared (JHK s) imaging polarimetry of a bright-rimmed cloud (SFO 74). The polarization vector maps clearly show that the magnetic field in the layer just behind the bright rim is running along the rim, quite different from its ambient magnetic field. The direction of the magnetic field just behind the tip rim is almost perpendicular to that of the incident UV radiation, and the magnetic field configuration appears to be symmetric as a whole with respect to the cloud symmetry axis. We estimated the column and number densities in the two regions (just inside and far inside the tip rim) and then derived the magnetic field strength, applying the Chandrasekhar-Fermi method. The estimated magnetic field strength just inside the tip rim, ~90 ?G, is stronger than that far inside, ~30 ?G. This suggests that the magnetic field strength just inside the tip rim is enhanced by the UV-radiation-induced shock. The shock increases the density within the top layer around the tip and thus increases the strength of the magnetic field. The magnetic pressure seems to be comparable to the turbulent one just inside the tip rim, implying a significant contribution of the magnetic field to the total internal pressure. The mass-to-flux ratio was estimated to be close to the critical value just inside the tip rim. We speculate that the flat-topped bright rim of SFO 74 could be formed by the magnetic field effect.

  2. An Investigation of the Detectability of Cloud-to-Ground Strokes by the Lightning Imaging Sensor

    NASA Astrophysics Data System (ADS)

    Franklin, V.; Bitzer, P. M.; Christian, H. J.

    2012-12-01

    Lightning data from the Lightning Imaging Sensor (LIS) is compared with several ground based sensing networks in order to determine the percentage of cloud-to-ground lightning strokes detected from space. Diverging from previous research, stroke level data from the National Lightning Detection Network (NLDN) is compared to LIS groups. A LIS group is considered a match if it lies within 10 ms and 50 km of the NLDN stroke. In addition, VLF/LF sources detected by the Huntsville Alabama Marx Meter Array (HAMMA) and VHF sources detected by the North Alabama Lightning Mapping Array (NALMA) are used to differentiate between lightning events detected or not detected by LIS. The electric field change measurements from HAMMA allow for the analysis of individual electric field waveforms of both intracloud and cloud-to-ground lightning. We investigate if and how properties such as the peak current, height, and stroke type determine whether or not an event is detected by LIS. Additionally, examining the timing and location differences between the ground based sensors and LIS provides a better understanding of which component of the discharge is detected by each.

  3. NEAR-IR IMAGING POLARIMETRY TOWARD A BRIGHT-RIMMED CLOUD: MAGNETIC FIELD IN SFO 74

    SciTech Connect

    Kusune, Takayoshi; Sugitani, Koji; Miao, Jingqi; Tamura, Motohide; Kwon, Jungmi; Sato, Yaeko; Watanabe, Makoto; Nishiyama, Shogo; Nagayama, Takahiro; Sato, Shuji

    2015-01-01

    We have made near-infrared (JHK {sub s}) imaging polarimetry of a bright-rimmed cloud (SFO 74). The polarization vector maps clearly show that the magnetic field in the layer just behind the bright rim is running along the rim, quite different from its ambient magnetic field. The direction of the magnetic field just behind the tip rim is almost perpendicular to that of the incident UV radiation, and the magnetic field configuration appears to be symmetric as a whole with respect to the cloud symmetry axis. We estimated the column and number densities in the two regions (just inside and far inside the tip rim) and then derived the magnetic field strength, applying the Chandrasekhar-Fermi method. The estimated magnetic field strength just inside the tip rim, ?90 ?G, is stronger than that far inside, ?30 ?G. This suggests that the magnetic field strength just inside the tip rim is enhanced by the UV-radiation-induced shock. The shock increases the density within the top layer around the tip and thus increases the strength of the magnetic field. The magnetic pressure seems to be comparable to the turbulent one just inside the tip rim, implying a significant contribution of the magnetic field to the total internal pressure. The mass-to-flux ratio was estimated to be close to the critical value just inside the tip rim. We speculate that the flat-topped bright rim of SFO 74 could be formed by the magnetic field effect.

  4. Online self-service processing system of ZY-3 satellite: a prospective study of image cloud services

    NASA Astrophysics Data System (ADS)

    Wang, Hongyan; Wang, Huabin; Shi, Shaoyu

    2015-12-01

    The strong demands for satellite images are increasing not only in professional fields, but also in the non-professionals. But the online map services with up-to-date satellite images can serve few demands. One challenge is how to provide online processing service, which need to handle real-time online data-intensive geospatial computation and visualization. Under the background of the development of cloud computing technology, the problem can be figured out partly. The other challenge is how to implement user-customized online processing without professional background and knowledge. An online self-service processing system of ZY-3 Satellite images is designed to implement an on-demand service mode in this paper. It will work with only some simple parameters being set up for the non-professionals without having to care about the specific processing steps. And the professionals can assemble the basic processing services to a service chain, which can work out a more complex processing and a better result. This intelligent self-service online system for satellite images processing, which is called the prototype of satellite image cloud service in this paper, is accelerated under the development of cloud computing technology and researches on data-intensive computing. To realize the goal, the service mode and framework of the online self-service processing system of ZY-3 Satellite images are figured out in this paper. The details of key technologies are also discussed, including user space virtualization management, algorithm-level parallel image processing, image service chain construction, etc. And the experimental system is built up as a prospective study of image cloud services.

  5. Arctic Clouds

    Atmospheric Science Data Center

    2013-04-19

    ... a stereo anaglyph enables observation of multiple cloud layers. The images are centered at about 75 degrees north latitude, near ... cold, stable air causes the clouds to persist in stratified layers, and this layering is evident in the stereo view. Near the top center, a ...

  6. Characterizing growth patterns in longitudinal MRI using image contrast

    NASA Astrophysics Data System (ADS)

    Vardhan, Avantika; Prastawa, Marcel; Vachet, Clement; Piven, Joseph; Gerig, Guido

    2014-03-01

    Understanding the growth patterns of the early brain is crucial to the study of neuro-development. In the early stages of brain growth, a rapid sequence of biophysical and chemical processes take place. A crucial component of these processes, known as myelination, consists of the formation of a myelin sheath around a nerve fiber, enabling the effective transmission of neural impulses. As the brain undergoes myelination, there is a subsequent change in the contrast between gray matter and white matter as observed in MR scans. In this work, gray-white matter contrast is proposed as an effective measure of appearance which is relatively invariant to location, scanner type, and scanning conditions. To validate this, contrast is computed over various cortical regions for an adult human phantom. MR (Magnetic Resonance) images of the phantom were repeatedly generated using different scanners, and at different locations. Contrast displays less variability over changing conditions of scan compared to intensity-based measures, demonstrating that it is less dependent than intensity on external factors. Additionally, contrast is used to analyze longitudinal MR scans of the early brain, belonging to healthy controls and Down's Syndrome (DS) patients. Kernel regression is used to model subject-specific trajectories of contrast changing with time. Trajectories of contrast changing with time, as well as time-based biomarkers extracted from contrast modeling, show large differences between groups. The preliminary applications of contrast based analysis indicate its future potential to reveal new information not covered by conventional volumetric or deformation-based analysis, particularly for distinguishing between normal and abnormal growth patterns.

  7. Application of Cloude's target decomposition theorem to polarimetric imaging radar data

    NASA Technical Reports Server (NTRS)

    Vanzyl, Jakob J.

    1993-01-01

    In this paper we applied Cloude's decomposition to imaging radar polarimetry. We show in detail how the decomposition results can guide the interpretation of scattering from vegetated areas. For multifrequency polarimetric radar measurements of a clear-cut area, the decomposition leads us to conclude that the vegetation is probably thin compared to even the C-band radar wavelength of 6 cm. For a frosted area, we notice an increased amount of even number of reflection scattering at P-band and L-band, probably the result of penetration through the coniferous canopy resulting in trunk-ground double reflection scattering. However, the scattering for the forested area is still dominated by scattering from randomly oriented cylinders. It is found that these cylinders are thicker than in the case of clear-cut areas, leading us to conclude that scattering from the branches probably dominates in this case.

  8. Thermal neutron image intensifier tube provides brightly visible radiographic pattern

    NASA Technical Reports Server (NTRS)

    Berger, H.; Kraska, I.; Niklas, W.; Schmidt, A.

    1967-01-01

    Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system.

  9. Water vapor motion signal extraction from FY-2E longwave infrared window images for cloud-free regions: The temporal difference technique

    NASA Astrophysics Data System (ADS)

    Yang, Lu; Wang, Zhenhui; Chu, Yanli; Zhao, Hang; Tang, Min

    2014-11-01

    The aim of this study is to calculate the low-level atmospheric motion vectors (AMVs) in clear areas with FY-2E IR2 window (11.59-12.79 ?m) channel imagery, where the traditional cloud motion wind technique fails. A new tracer selection procedure, which we call the temporal difference technique, is demonstrated in this paper. This technique makes it possible to infer low-level wind by tracking features in the moisture pattern that appear as brightness temperature ( T B) differences between consecutive sequences of 30-min-interval FY-2E IR2 images over cloud-free regions. The T B difference corresponding to a 10% change in water vapor density is computed with the Moderate Resolution Atmospheric Transmission (MODTRAN4) radiative transfer model. The total contribution from each of the 10 layers is analyzed under four typical atmospheric conditions: tropical, midlatitude summer, U.S. standard, and midlatitude winter. The peak level of the water vapor weighting function for the four typical atmospheres is assigned as a specific height to the T B "wind". This technique is valid over cloud-free ocean areas. The proposed algorithm exhibits encouraging statistical results in terms of vector difference (VD), speed bias (BIAS), mean vector difference (MVD), standard deviation (SD), and root-mean-square error (RMSE), when compared with the wind field of NCEP reanalysis data and rawinsonde observations.

  10. Stratospheric imaging of polar mesospheric clouds: A new window on small-scale atmospheric dynamics

    NASA Astrophysics Data System (ADS)

    Miller, A. D.; Fritts, D. C.; Chapman, D.; Jones, G.; Limon, M.; Araujo, D.; Didier, J.; Hillbrand, S.; Kjellstrand, C. B.; Korotkov, A.; Tucker, G.; Vinokurov, Y.; Wan, K.; Wang, L.

    2015-07-01

    Instabilities and turbulence extending to the smallest dynamical scales play important roles in the deposition of energy and momentum by gravity waves throughout the atmosphere. However, these dynamics and their effects have been impossible to quantify to date due to lack of observational guidance. Serendipitous optical images of polar mesospheric clouds at 82 km obtained by star cameras aboard a cosmology experiment deployed on a stratospheric balloon provide a new observational tool, revealing instability and turbulence structures extending to spatial scales < 20 m. At 82 km, this resolution provides sensitivity extending to the smallest turbulence scale not strongly influenced by viscosity: the "inner scale" of turbulence, l010(?3/?)1/4. Such images represent a new window into small-scale dynamics that occur throughout the atmosphere but are impossible to observe in such detail at any other altitude. We present a sample of images revealing a range of dynamics features and employ numerical simulations that resolve these dynamics to guide our interpretation of several observed events.

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

    NASA Astrophysics Data System (ADS)

    Lichtenauer, J. F.; Sirmacek, B.

    2015-08-01

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

  12. Polarization of Directly Imaged Young Giant Planets as a Probe of Mass, Rotation, and Clouds

    NASA Technical Reports Server (NTRS)

    Marley, Mark Scott; Sengupta, Sujan

    2012-01-01

    Young, hot gas giant planets at large separations from their primaries have been directly imaged around several nearby stars. More such planets will likely be detected by ongoing and new imaging surveys with instruments such as the Gemini Planet Imager (GPI). Efforts continue to model the spectra of these planets in order to constrain their masses, effective temperatures, composition, and cloud structure. One potential tool for analyzing these objects, which has received relatively less attention, is polarization. Linear polarization of gas giant exoplanets can arise from the combined influences of light scattering by atmospheric dust and a rotationally distorted shape. The oblateness of gas giant planet increases of course with rotation rate and for fixed rotation also rises with decreasing gravity. Thus young, lower mass gas giant planets with youthful inflated radii could easily have oblateness greater than that of Saturn s 10%. We find that polarizations of over 1% may easily be produced in the near-infrared in such cases. This magnitude of polarization may be measurable by GPI and other instruments. Thus if detected, polarization of a young Jupiter places constraints on the combination of its gravity, rotation rate, and degree of cloudiness. We will present results of our multiple scattering analysis coupled with a self-consistent dusty atmospheric models to demonstrate the range of polarizations that might be expected from resolved exoplanets and the range of parameter space that such observations may inform.

  13. Fast Occlusion and Shadow Detection for High Resolution Remote Sensing Image Combined with LIDAR Point Cloud

    NASA Astrophysics Data System (ADS)

    Hu, X.; Li, X.

    2012-08-01

    The orthophoto is an important component of GIS database and has been applied in many fields. But occlusion and shadow causes the loss of feature information which has a great effect on the quality of images. One of the critical steps in true orthophoto generation is the detection of occlusion and shadow. Nowadays LiDAR can obtain the digital surface model (DSM) directly. Combined with this technology, image occlusion and shadow can be detected automatically. In this paper, the Z-Buffer is applied for occlusion detection. The shadow detection can be regarded as a same problem with occlusion detection considering the angle between the sun and the camera. However, the Z-Buffer algorithm is computationally expensive. And the volume of scanned data and remote sensing images is very large. Efficient algorithm is another challenge. Modern graphics processing unit (GPU) is much more powerful than central processing unit (CPU). We introduce this technology to speed up the Z-Buffer algorithm and get 7 times increase in speed compared with CPU. The results of experiments demonstrate that Z-Buffer algorithm plays well in occlusion and shadow detection combined with high density of point cloud and GPU can speed up the computation significantly.

  14. Remote sensing of cloud, aerosol and water vapor properties from the Moderate Resolution Imaging Spectrometer (MODIS)

    NASA Technical Reports Server (NTRS)

    King, M. D.

    1992-01-01

    The Moderate Resolution Imaging Spectrometer (MODIS) is an Earth-viewing sensor being developed as a facility instrument for the Earth Observing System (EOS) to be launched in the late 1990s. MODIS consists of two separate instruments that scan a swath width sufficient to provide nearly complete global coverage every two days from a polar-orbiting, Sun-synchronous, platform at an altitude of 705 km. Of primary interest for studies of atmospheric physics is the MODIS-N (nadir) instrument which will provide images in 36 spectral bands between 0.415 and 14.235 micrometers with spatial resoulutions of 250 m (2 bands), 500 m (5 bands) and 1000 m (29 bands). These bands have been carefully selected to enable advanced studies of land, ocean and atmosperhic processes. The intent of this lecture is to describe the current status of MODIS-N and its companion instrument MODIS-T (tilt), a tiltable cross-track scanning radiometer with 32 uniformly spaced channels between 0.410 and 0.875 micrometers, and to describe the physical principles behind the development of MODIS for the remote sensing of atmospheric properties. Primary emphasis will be placed on the main atmospheric applications of determining the optical, microphysical and physical properties of clouds and aerosol particles form spectral-reflection and thermal-emission measurements. In addition to cloud and aerosol properties, MODIS-N will be utilized for the determination of the total precipitable water vapor over land and atmospheric stability. The physical principles behind the determination of each of these atmospheric products will be described herein.

  15. Neptune's cloud and haze variations 1994-2008 from 500 HST-WFPC2 images

    NASA Astrophysics Data System (ADS)

    Karkoschka, Erich

    2011-10-01

    The analysis of all suitable images taken of Neptune with the Wide Field Planetary Camera 2 on the Hubble Space Telescope between 1994 and 2008 revealed the following results. The activity of discrete cloud features located near Neptune's tropopause remained roughly constant within each year but changed significantly on the time scale of 5 years. Discrete clouds covered 1% of the disk on average, but more than 2% in 2002. The other 99% of the disk probed Neptune's hazes at lower altitudes. At red and near-infrared wavelengths, two dark bands around -70 and 10 latitude were perfectly steady and originated in the upper two scale heights of the troposphere, either by decreased haze opacity or by an increased methane relative humidity. At blue wavelengths, a dark band between -60 and -30 latitude was most obvious during the early years, caused by dark aerosols below the 3-bar level with single scattering albedos reduced by 0.04, and this contrast was constant between 410 and 630 nm wavelength. The dark band decayed exponentially with a time constant of 5 1 years, which can be explained by settling of the dark aerosols at a rate of 1 bar pressure difference per year. The other latitudes brightened with the same time constant but lower amplitudes. The only exception was a darkening event in the 15-30 latitude region between 1994 and 1996, which coincides with two dark spots observed in the same region during the same time period, the only dark spots seen since Voyager. The dark aerosols had a similar latitudinal distribution as the discrete clouds near the tropopause, although both were separated by four scale heights. Photometric analysis revealed a phase coefficient of 0.0028 0.0010 mag/deg for the 0-2 phase-angle range observable from Earth. Neptune's sub-Earth latitude varied by less than 3 throughout the observation period providing a data set with almost constant viewing geometry. The trends observed up to 2008 continued into 2010 based on images taken with the Wide Field Camera 3.

  16. Point cloud generation from aerial image data acquired by a quadrocopter type micro unmanned aerial vehicle and a digital still camera.

    PubMed

    Rosnell, Tomi; Honkavaara, Eija

    2012-01-01

    The objective of this investigation was to develop and investigate methods for point cloud generation by image matching using aerial image data collected by quadrocopter type micro unmanned aerial vehicle (UAV) imaging systems. Automatic generation of high-quality, dense point clouds from digital images by image matching is a recent, cutting-edge step forward in digital photogrammetric technology. The major components of the system for point cloud generation are a UAV imaging system, an image data collection process using high image overlaps, and post-processing with image orientation and point cloud generation. Two post-processing approaches were developed: one of the methods is based on Bae Systems' SOCET SET classical commercial photogrammetric software and another is built using Microsoft(®)'s Photosynth™ service available in the Internet. Empirical testing was carried out in two test areas. Photosynth processing showed that it is possible to orient the images and generate point clouds fully automatically without any a priori orientation information or interactive work. The photogrammetric processing line provided dense and accurate point clouds that followed the theoretical principles of photogrammetry, but also some artifacts were detected. The point clouds from the Photosynth processing were sparser and noisier, which is to a large extent due to the fact that the method is not optimized for dense point cloud generation. Careful photogrammetric processing with self-calibration is required to achieve the highest accuracy. Our results demonstrate the high performance potential of the approach and that with rigorous processing it is possible to reach results that are consistent with theory. We also point out several further research topics. Based on theoretical and empirical results, we give recommendations for properties of imaging sensor, data collection and processing of UAV image data to ensure accurate point cloud generation. PMID:22368479

  17. Point Cloud Generation from Aerial Image Data Acquired by a Quadrocopter Type Micro Unmanned Aerial Vehicle and a Digital Still Camera

    PubMed Central

    Rosnell, Tomi; Honkavaara, Eija

    2012-01-01

    The objective of this investigation was to develop and investigate methods for point cloud generation by image matching using aerial image data collected by quadrocopter type micro unmanned aerial vehicle (UAV) imaging systems. Automatic generation of high-quality, dense point clouds from digital images by image matching is a recent, cutting-edge step forward in digital photogrammetric technology. The major components of the system for point cloud generation are a UAV imaging system, an image data collection process using high image overlaps, and post-processing with image orientation and point cloud generation. Two post-processing approaches were developed: one of the methods is based on Bae Systems’ SOCET SET classical commercial photogrammetric software and another is built using Microsoft®’s Photosynth™ service available in the Internet. Empirical testing was carried out in two test areas. Photosynth processing showed that it is possible to orient the images and generate point clouds fully automatically without any a priori orientation information or interactive work. The photogrammetric processing line provided dense and accurate point clouds that followed the theoretical principles of photogrammetry, but also some artifacts were detected. The point clouds from the Photosynth processing were sparser and noisier, which is to a large extent due to the fact that the method is not optimized for dense point cloud generation. Careful photogrammetric processing with self-calibration is required to achieve the highest accuracy. Our results demonstrate the high performance potential of the approach and that with rigorous processing it is possible to reach results that are consistent with theory. We also point out several further research topics. Based on theoretical and empirical results, we give recommendations for properties of imaging sensor, data collection and processing of UAV image data to ensure accurate point cloud generation. PMID:22368479

  18. Automated method for the removal of unwanted nonperiodic patterns from forensic images

    NASA Astrophysics Data System (ADS)

    Capel, David; Zisserman, Andrew; Bramble, Simon K.; Compton, David

    1999-02-01

    The aim of this work is the removal of distracting background patterns from forensic evidence so that the evidence is rendered more visible. An example is the image of a finger print on a non-periodic background. The method involves registering the image with a control image of the background pattern that we seek to remove. A statistical comparison of the registered images identifies the latent mark.

  19. A method of using commercial virtual satellite image to check the pattern painting spot effect

    NASA Astrophysics Data System (ADS)

    Wang, Zheng-gang; Kang, Qing; Shen, Zhi-qiang; Cui, Chang-bin

    2014-02-01

    A method of using commercial virtual satellite image to check the pattern painting spot effect contrast with the satellite images before painting and after painting have been discussed. Using a housetop as the testing platform analyses and discusses the factors' influence such as resolution of satellite image, spot size and color of pattern painting spot and pattern painting camouflage method choosing to the plan implement. The pattern painting design and spot size used in the testing has been ensured, and housetop pattern painting has been painted. Finally, the small spot pattern painting camouflage effect of engineering using upon painting pattern size, color and texture have been checked, contrasting with the satellite image before painting and after painting.

  20. Resolution analysis in computational imaging with patterned illumination and single-pixel detection

    NASA Astrophysics Data System (ADS)

    Rodriguez, A. D.; Clemente, P.; Irles, E.; Tajahuerce, E.; Lancis, J.

    2014-08-01

    In computational imaging by pattern projection a sequence of microstructured light patterns codified onto a programmable spatial light modulator is used to sample an object. The patterns are used as generalized measurement modes where the object information is expressed. Our paper makes two specific contributions within the field of single-pixel imaging through patterned illumination. First, we perform an analysis of the optical resolution of the computational image. This resolution is shown not to be limited at all by the optical quality of the collection optics. This result is proved by using a low NA microscope objective for imaging at a CCD camera. Spatial frequencies that are not transmitted through this low quality optics are demonstrated to be present in the retrieved image through patterned illumination. Second, we experimentally demonstrate the capability of our technique to properly recover an image even when an optical diffuser is located in between the sample and the single-pixel detector.

  1. Cips (Cloud Imaging and Particle Size Experiment) Observations of a Newly Discovered Population of Very Large Ice Particles in Polar Mesospheric Clouds

    NASA Astrophysics Data System (ADS)

    Rusch, D. W.; Thomas, G. E.; Chandran, A.; Merkel, A. W.; Lumpe, J. D., Jr.; Randall, C. E.; Olivero, J. J.; Bailey, S. M.; Russell, J. M., III

    2014-12-01

    Observations by the Cloud Imaging and Particle Size (CIPS) instrument on the Aeronomy of Ice in the Mesosphere (AIM) satellite have demonstrated the existence of Polar Mesospheric Cloud (PMC) regions populated by particles in the size range between 60 and 100 nm (radii of equivalent volume spheres). It is known from lidar, SOFIE, and CIPS measurements that typical mean PMC particle sizes are of the order of 40-50 nm. Determination of particle sizes by CIPS is accomplished by measuring the scattering of solar radiation at various scattering angles at a spatial resolution of 25 km2. PMC with ice particles principally in this 60-100 nm range are observed in 15 to 20 % of all CIPS measurements. These very large particle (VLP) events occur over spatially coherent areas. They are generally associated with regions of low cloud albedo (brightness) and ice water content. We postulate that at least part of this VLP population exists due to the action of long-period gravity waves in the low-temperature summertime mesopause region. We demonstrate the proposed mechanism through use of the 2D Community Aerosol and Radiation Model for Atmospheres (CARMA), which simulates the evolution of ice particles over several cycles of a family of modeled gravity waves. The model results are consistent with a VLP population in the cold troughs of monochromatic gravity waves with horizontal wavelengths of 600 km and periods of 10 hours (Chandran et al., 2013).

  2. Particle image pattern mutual information and uncertainty estimation for particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Xue, Zhenyu; Charonko, John J.; Vlachos, Pavlos P.

    2015-07-01

    In this work we introduce a new measure for particle image velocimetry (PIV) cross-correlation quality and establish analytically its connection to the basic PIV theory. This metric, which we term mutual information (MI), can be used to estimate the number of correlated particles and connect to the PIV measurement uncertainty quantification. In PIV the number of particles in common between two consecutive frames forms the basis of the cross-correlation operation that yields the velocity measurement. Since the particle image pattern intensity distribution within each image represents the available signal, the inherent number of common particle pairs between the cross-correlated images, which can be thought of as the amount of mutual information, governs the potential accuracy of the PIV measurement. The number of common particle pairs between the images can be expressed by the product of the image density NI, and the fraction of particles that leave the frame due to in-plane and out-of-plane motion FI and FO, respectively. It has previously been shown that this parameter, NIFIFO, directly relates to the validity of a PIV measurement. However, in real experiments, NIFIFO is unknown and difficult to calculate. Here we propose to overcome this limitation by introducing a new metric (MI), which directly computes the apparent amount of common information contained in the particle patterns of two consecutive images without prior knowledge of the particle field. Both theoretical derivation and experimental results are provided to show that MI and NIFIFO represent the same characteristics of a PIV measurement. Subsequently, MI is used to develop a model for PIV uncertainty estimation. This metric and the corresponding uncertainty model presented herein are applied to both standard and a filtered phase-only (robust phase correlation) correlation methods. These advancements lead to robust uncertainty estimation models, which are tested against both synthetic benchmark data as well as real experimental measurements. For all cases considered here, {{U}68.5} and {{U}95} uncertainties demonstrated coverage factors approximately equal to the theoretically expected values of 68.5% and 95%, which reflect 1? and 2? levels in a normal distribution model respectively.

  3. Cloud radiative properties and aerosol - cloud interaction

    NASA Astrophysics Data System (ADS)

    Viviana Vladutescu, Daniela; Gross, Barry; Li, Clement; Han, Zaw

    2015-04-01

    The presented research discusses different techniques for improvement of cloud properties measurements and analysis. The need for these measurements and analysis arises from the high errors noticed in existing methods that are currently used in retrieving cloud properties and implicitly cloud radiative forcing. The properties investigated are cloud fraction (cf) and cloud optical thickness (COT) measured with a suite of collocated remote sensing instruments. The novel approach makes use of a ground based "poor man's camera" to detect cloud and sky radiation in red, green, and blue with a high spatial resolution of 30 mm at 1km. The surface-based high resolution photography provides a new and interesting view of clouds. As the cloud fraction cannot be uniquely defined or measured, it depends on threshold and resolution. However as resolution decreases, cloud fraction tends to increase if the threshold is below the mean, and vice versa. Additionally cloud fractal dimension also depends on threshold. Therefore these findings raise concerns over the ability to characterize clouds by cloud fraction or fractal dimension. Our analysis indicate that Principal Component analysis may lead to a robust means of quantifying cloud contribution to radiance. The cloud images are analyzed in conjunction with a collocated CIMEL sky radiometer, Microwave Radiometer and LIDAR to determine homogeneity and heterogeneity. Additionally, MFRSR measurements are used to determine the cloud radiative properties as a validation tool to the results obtained from the other instruments and methods. The cloud properties to be further studied are aerosol- cloud interaction, cloud particle radii, and vertical homogeneity.

  4. Uranus' Persistent Patterns and Features from High-SNR Imaging in 2012-2014

    NASA Astrophysics Data System (ADS)

    Fry, Patrick M.; Sromovsky, Lawrence A.; de Pater, Imke; Hammel, Heidi B.; Marcus, Phillip

    2015-11-01

    Since 2012, Uranus has been the subject of an observing campaign utilizing high signal-to-noise imaging techniques at Keck Observatory (Fry et al. 2012, Astron. J. 143, 150-161). High quality observing conditions on four observing runs of consecutive nights allowed longitudinally-complete coverage of the atmosphere over a period of two years (Sromovsky et al. 2015, Icarus 258, 192-223). Global mosaic maps made from images acquired on successive nights in August 2012, November 2012, August 2013, and August 2014, show persistent patterns, and six easily distinguished long-lived cloud features, which we were able to track for long periods that ranged from 5 months to over two years. Two at similar latitudes are associated with dark spots, and move with the atmospheric zonal flow close to the location of their associated dark spot instead of following the flow at the latitude of the bright features. These features retained their morphologies and drift rates in spite of several close interactions. A second pair of features at similar latitudes also survived several close approaches. Several of the long-lived features also exhibited equatorward drifts and latitudinal oscillations. Also persistent are a remarkable near-equatorial wave feature and global zonal band structure. We will present imagery, maps, and analyses of these phenomena.PMF and LAS acknowledge support from NASA Planetary Astronomy Program; PMF and LAS acknowledge funding and technical support from W. M. Keck Observatory. We thank those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. Without their generous hospitality none of our groundbased observations would have been possible.

  5. ABrIL - Advanced Brain Imaging Lab : a cloud based computation environment for cooperative neuroimaging projects.

    PubMed

    Neves Tafula, Srgio M; Moreira da Silva, Ndia; Rozanski, Verena E; Silva Cunha, Joo Paulo

    2014-01-01

    Neuroscience is an increasingly multidisciplinary and highly cooperative field where neuroimaging plays an important role. Neuroimaging rapid evolution is demanding for a growing number of computing resources and skills that need to be put in place at every lab. Typically each group tries to setup their own servers and workstations to support their neuroimaging needs, having to learn from Operating System management to specific neuroscience software tools details before any results can be obtained from each setup. This setup and learning process is replicated in every lab, even if a strong collaboration among several groups is going on. In this paper we present a new cloud service model - Brain Imaging Application as a Service (BiAaaS) - and one of its implementation - Advanced Brain Imaging Lab (ABrIL) - in the form of an ubiquitous virtual desktop remote infrastructure that offers a set of neuroimaging computational services in an interactive neuroscientist-friendly graphical user interface (GUI). This remote desktop has been used for several multi-institution cooperative projects with different neuroscience objectives that already achieved important results, such as the contribution to a high impact paper published in the January issue of the Neuroimage journal. The ABrIL system has shown its applicability in several neuroscience projects with a relatively low-cost, promoting truly collaborative actions and speeding up project results and their clinical applicability. PMID:25570014

  6. Three-Dimensional Transcranial Ultrasound Imaging of Microbubble Clouds Using a Sparse Hemispherical Array

    PubMed Central

    O'Reilly, Meaghan A.; Jones, Ryan M.; Hynynen, Kullervo

    2014-01-01

    There is an increasing interest in bubble-mediated focused ultrasound (FUS) interventions in the brain. However, current technology lacks the ability to spatially monitor the interaction of the microbubbles with the applied acoustic field, something which is critical for safe clinical translation of these treatments. Passive acoustic mapping could offer a means for spatially monitoring microbubble emissions that relate to bubble activity and associated bioeffects. In this study a hemispherical receiver array was integrated within an existing transcranial therapy array to create a device capable of both delivering therapy and monitoring the process via passive imaging of bubble clouds. A 128-element receiver array was constructed and characterized for varying bubble concentrations and source spacings. Initial in vivo feasibility testing was performed. The system was found to be capable of monitoring bubble emissions down to single bubble events through an ex vivo human skull. The lateral resolution of the system was found to be between 1.25-2 mm and the axial resolution between 2-3.5 mm, comparable to the resolution of MRI-based temperature monitoring during thermal FUS treatments in the brain. The results of initial in vivo experiments show that bubble activity can be mapped starting at pressure levels below the threshold for Blood-Brain barrier disruption. This study presents a feasible solution for imaging bubble activity during cavitation-mediated FUS treatments in the brain. PMID:24658252

  7. Design of an in-line, digital holographic imaging system for airborne measurement of clouds.

    PubMed

    Spuler, Scott M; Fugal, Jacob

    2011-04-01

    We discuss the design and performance of an airborne (underwing) in-line digital holographic imaging system developed for characterizing atmospheric cloud water droplets and ice particles in situ. The airborne environment constrained the design space to the simple optical layout that in-line non-beam-splitting holography affords. The desired measurement required the largest possible sample volume in which the smallest desired particle size (?5 ?m) could still be resolved, and consequently the magnification requirement was driven by the pixel size of the camera and this particle size. The resulting design was a seven-element, double-telecentric, high-precision optical imaging system used to relay and magnify a hologram onto a CCD surface. The system was designed to preserve performance and high resolution over a wide temperature range. Details of the optical design and construction are given. Experimental results demonstrate that the system is capable of recording holograms that can be reconstructed with resolution of better than 6.5 ?m within a 15 cm(3) sample volume. PMID:21460907

  8. ENVI Services Engine: Earth and Planetary Image Processing for the Cloud

    NASA Astrophysics Data System (ADS)

    O'Connor, A. S.; Lausten, K.; Heightley, K.; Harris, T.

    2012-12-01

    The geospatial imagery analysis and exploitation community has a growing need for online analytic capabilities. Work previously done on desktop workstations must migrate to a web-accessible environment to mitigate growing data volumetrics, bandwidth usage, and end user requirements. Web based applications (or 'apps') are intended to apply analytic methods, procedures, and routines to image datasets stored within centralized server repositories. Exelis Visual information Solutions (VIS) developed an enterprise-enabled processing engine that provides remote users access to the power of ENVI image analysis and IDL applications from a web or mobile client interface. The working name for this capability is the ENVI and IDL Services Engine (ESE). This engine now enables the remote user to gain access to the same compiled ENVI and IDL functions and procedures that remote sensing scientists have utilized for decades at the desktop level. ESE operates in a RESTful state, listening for http calls to arrive that initiate a data processing operation once those messages are registered. ESE is middleware agnostic, meaning users can implement this capability using their current enterprise architecture such as ArcGIS Server or GeoServer. Flexibility and openness in middleware components is achieved through the use of OGC standards for message and data transfer. ESE represents bringing long term earth science monitoring analysis capabilities to the cloud, harnessing existing ENVI and IDL tools and deploying them to the enterprise, and improving access to earth and planetary science data.

  9. Visibility-reducing species in the denver "brown cloud"II. Sources and temporal patterns

    NASA Astrophysics Data System (ADS)

    Wolff, G. T.; Countess, R. J.; Groblicki, P. J.; Ferman, M. A.; Cadle, S. H.; Muhlbaier, J. L.

    The chemical and optical measurements collected at the General Motors Research Laboratories' site during the 1978 Denver "brown cloud" study are combined with data on energy consumption and emissions, as well as the use of tracer techniques, to estimate the contributions of the various sources to the fine paniculate mass (FPM) and the visual range reduction (VRR). Although no single source dominates either the FPM or the VRR, combustion processes account for over 80% of both. The major contributors to both the FPM and VRR are: motor vehicles, 26 and 27% (diesel trucks, 8 and 12%; light-duty noncatalyst vehicles. 14 and 9%; light-duty catalyst-equipped vehicles, 4 and 5% and tire rubber, negligible and 1%), coal combustion, > 20 and > 25%, and wood burning, 12 and 18%. The remainders of the FPM and VRR are due chiefly to fuel oil and natural-gas combustion and crustal and fly ash material. The motor vehicles and the wood combustion are the principal sources of both elemental and organic carbon particles while the coal combustion is the most important source of paniculate sulfate and nitrate precursors. Essentially, all the carbonaceous particles appear to be primary particles while most of the sulfate appears to be produced by a heterogeneous process. Both heterogeneous and homogeneous (photochemical) mechanisms appear to be producing nitrate, with the photochemical one being more important.

  10. Workshop on Standards for Image Pattern Recognition. Computer Seience & Technology Series.

    ERIC Educational Resources Information Center

    Evans, John M. , Ed.; And Others

    Automatic image pattern recognition techniques have been successfully applied to improving productivity and quality in both manufacturing and service applications. Automatic Image Pattern Recognition Algorithms are often developed and tested using unique data bases for each specific application. Quantitative comparison of different approaches and

  11. Detecting, grouping, and structure inference for invariant repetitive patterns in images.

    PubMed

    Cai, Yunliang; Baciu, George

    2013-06-01

    The efficient and robust extraction of invariant patterns from an image is a long-standing problem in computer vision. Invariant structures are often related to repetitive or near-repetitive patterns. The perception of repetitive patterns in an image is strongly linked to the visual interpretation and composition of textures. Repetitive patterns are products of both repetitive structures as well as repetitive reflections or color patterns. In other words, patterns that exhibit near-stationary behavior provide rich information about objects, their shapes, and their texture in an image. In this paper, we propose a new algorithm for repetitive pattern detection and grouping. The algorithm follows the classical region growing image segmentation scheme. It utilizes a mean-shift-like dynamic to group local image patches into clusters. It exploits a continuous joint alignment to: 1) match similar patches, and 2) refine the subspace grouping. We also propose an algorithm for inferring the composition structure of the repetitive patterns. The inference algorithm constructs a data-driven structural completion field, which merges the detected repetitive patterns into specific global geometric structures. The result of higher level grouping for image patterns can be used to infer the geometry of objects and estimate the general layout of a crowded scene. PMID:23481858

  12. Evaluation of a cloud-based local-read paradigm for imaging evaluations in oncology clinical trials for lung cancer

    PubMed Central

    Kobayashi, Naomi; Bonnard, Eric; Charbonnier, Colette; Yamamichi, Junta; Mizobe, Hideaki; Kimura, Shinya

    2015-01-01

    Background Although tumor response evaluated with radiological imaging is frequently used as a primary endpoint in clinical trials, it is difficult to obtain precise results because of inter- and intra-observer differences. Purpose To evaluate usefulness of a cloud-based local-read paradigm implementing software solutions that standardize imaging evaluations among international investigator sites for clinical trials of lung cancer. Material and Methods Two studies were performed: KUMO I and KUMO I Extension. KUMO I was a pilot study aiming at demonstrating the feasibility of cloud implementation and identifying issues regarding variability of evaluations among sites. Chest CT scans at three time-points from baseline to progression, from 10 patients with lung cancer who were treated with EGFR tyrosine kinase inhibitors, were evaluated independently by two oncologists (Japan) and one radiologist (France), through a cloud-based software solution. The KUMO I Extension was performed based on the results of KUMO I. Results KUMO I showed discordance rates of 40% for target lesion selection, 70% for overall response at the first time-point, and 60% for overall response at the second time-point. Since the main reason for the discordance was differences in the selection of target lesions, KUMO I Extension added a cloud-based quality control service to achieve a consensus on the selection of target lesions, resulting in an improved rate of agreement of response evaluations. Conclusion The study shows the feasibility of imaging evaluations at investigator sites, based on cloud services for clinical studies involving multiple international sites. This system offers a step forward in standardizing evaluations of images among widely dispersed sites. PMID:26668754

  13. The Seasonal and Diurnal Patterns of net Ecosystem CO2 Exchange in a Subtropical Montane Cloud Forest.

    NASA Astrophysics Data System (ADS)

    Chu, H.; Lai, C.; Wu, C.; Hsia, Y.

    2008-12-01

    CO2 fluxes were measured by an open/closed path eddy covariance system at a natural regenerated 50-years-old yellow cypress (Chamaecyparis obtusa var. formosana) forest at Chi-Lan Mountain site (CLM site, 2435'N, 12125'E, 1650 m elevation), north-eastern Taiwan. CLM site is located at a relative uniform south-eastern-facing valley slope (15) characterized with year round fog occurrence and diurnal mountain-valley wind and can be classified as subtropical montane cloud forest. Based on measurement from July 2007 to June 2008, seasonal and diurnal patterns of CO2 fluxes were described and patterns under different cloudiness and foggy conditions were presented. Comparing with other cypress forests in temperate region, there is only a weak seasonal pattern of the CO2 fluxes at CLM site. Throughout the year, average incident photosynthetically active radiation in summer was almost the double of that in winter, whereas the difference of mean daytime CO2 fluxes among seasons was much less than the seasonal light difference. During summer when light intensity was higher, mean daytime CO2 fluxes reached -7.5 ?mol/m2/s in July and -8.8 ?mol/m2/s in August. As heavy fog accounted for 64% and 67% of the time in November and February, mean daytime CO2 fluxes dropped to -6.9 and -6.1 ?mol/m2/s respectively. With comparable higher incident radiation intensity (>1000 ?mol/m2/s), the CO2 fluxes were higher in overcast days than in clear days. In July 2007, clear days accounted for 30% of the month, light intensity reached its peak at midday, and however, CO2 fluxes didn't reach its highest value in the meanwhile. Canopy conductance calculated from the Penman-Monteith equation and measured latent heat fluxes both showed a midday depression at clear days, which indicated the regulation of transpiration by plant physiological mechanism. With comparable lower incident radiation intensity (<1000 ?mol/m2/s), the CO2 fluxes were higher in overcast days than in foggy days. The difference suggested that water droplets deposited on leaves might partially block the pathway of the gas exchange through stomata as canopy immersed in the very humid air. However, CO2 fluxes did not cease during foggy periods, as also supported by sap flow and leaf chamber measurements, the morphological characteristics of leaf or/and canopy structure might contribute to the well adaptability of this subtropical montane cloud forest to the humid environment.

  14. Photogrammetry and photo interpretation applied to analyses of cloud cover, cloud type, and cloud motion

    NASA Technical Reports Server (NTRS)

    Larsen, P. A.

    1972-01-01

    A determination was made of the areal extent of terrain obscured by clouds and cloud shadows on a portion of an Apollo 9 photograph at the instant of exposure. This photogrammetrically determined area was then compared to the cloud coverage reported by surface weather observers at approximately the same time and location, as a check on result quality. Stereograms prepared from Apollo 9 vertical photographs, illustrating various percentages of cloud coverage, are presented to help provide a quantitative appreciation of the degradation of terrain photography by clouds and their attendant shadows. A scheme, developed for the U.S. Navy, utilizing pattern recognition techniques for determining cloud motion from sequences of satellite photographs, is summarized. Clouds, turbulence, haze, and solar altitude, four elements of our natural environment which affect aerial photographic missions, are each discussed in terms of their effects on imagery obtained by aerial photography. Data of a type useful to aerial photographic mission planners, expressing photographic ground coverage in terms of flying height above terrain and camera focal length, for a standard aerial photograph format, are provided. Two oblique orbital photographs taken during the Apollo 9 flight are shown, and photo-interpretations, discussing the cloud types imaged and certain visible geographical features, are provided.

  15. Environmental controls in the water use patterns of a tropical cloud forest tree species, Drimys brasiliensis (Winteraceae).

    PubMed

    Eller, Cleiton B; Burgess, Stephen S O; Oliveira, Rafael S

    2015-04-01

    Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods. PMID:25716877

  16. Multi-Focus Raw Bayer Pattern Image Fusion for Single-Chip Camera

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Chen, Jibin

    2015-12-01

    In this paper, an efficient patch-based image fusion approach for raw images of single-chip imaging devices incorporated with the Bayer CFA pattern is presented. The multi-source raw Bayer pattern images are firstly parted into half overlapped patches. Then, the patches with maximum clarity measurement defined for raw Bayer pattern image are selected as the fused patches. Next, all the fused local patches are merged with weighted average method in order to reduce the blockness effect of fused raw Bayer pattern image. Finally, the real color fused image is obtained by gradient based demosaicing technology. The multi-source raw Bayer pattern data is fused before demosaicing, so that the multi-sensor system will be more efficient and the artifacts introduced in demosaicing processing do not accumulate in image fusion processing. For comparison, the raw images are also interpolated firstly, and then various image fusion methods are used to get the fused color images. Experimental results show that the proposed algorithm is valid and very effective.

  17. Pattern matching and adaptive image segmentation applied to plant reproduction by tissue culture

    NASA Astrophysics Data System (ADS)

    Vazquez Rueda, Martin G.; Hahn, Federico

    1999-03-01

    This paper shows the results obtained in a system vision applied to plant reproduction by tissue culture using adaptive image segmentation and pattern matching algorithms, this analysis improves the number of tissue obtained and minimize errors, the image features of tissue are considered join to statistical analysis to determine the best match and results. Tests make on potato plants are used to present comparative results with original images processed with adaptive segmentation algorithm and non adaptive algorithms and pattern matching.

  18. Multi-Scale Fractal Analysis of Image Texture and Pattern

    NASA Technical Reports Server (NTRS)

    Emerson, Charles W.; Lam, Nina Siu-Ngan; Quattrochi, Dale A.

    1999-01-01

    Analyses of the fractal dimension of Normalized Difference Vegetation Index (NDVI) images of homogeneous land covers near Huntsville, Alabama revealed that the fractal dimension of an image of an agricultural land cover indicates greater complexity as pixel size increases, a forested land cover gradually grows smoother, and an urban image remains roughly self-similar over the range of pixel sizes analyzed (10 to 80 meters). A similar analysis of Landsat Thematic Mapper images of the East Humboldt Range in Nevada taken four months apart show a more complex relation between pixel size and fractal dimension. The major visible difference between the spring and late summer NDVI images is the absence of high elevation snow cover in the summer image. This change significantly alters the relation between fractal dimension and pixel size. The slope of the fractal dimension-resolution relation provides indications of how image classification or feature identification will be affected by changes in sensor spatial resolution.

  19. Multi-Scale Fractal Analysis of Image Texture and Pattern

    NASA Technical Reports Server (NTRS)

    Emerson, Charles W.; Lam, Nina Siu-Ngan; Quattrochi, Dale A.

    1999-01-01

    Analyses of the fractal dimension of Normalized Difference Vegetation Index (NDVI) images of homogeneous land covers near Huntsville, Alabama revealed that the fractal dimension of an image of an agricultural land cover indicates greater complexity as pixel size increases, a forested land cover gradually grows smoother, and an urban image remains roughly self-similar over the range of pixel sizes analyzed (10 to 80 meters). A similar analysis of Landsat Thematic Mapper images of the East Humboldt Range in Nevada taken four months apart show a more complex relation between pixel size and fractal dimension. The major visible difference between the spring and late summer NDVI images of the absence of high elevation snow cover in the summer image. This change significantly alters the relation between fractal dimension and pixel size. The slope of the fractal dimensional-resolution relation provides indications of how image classification or feature identification will be affected by changes in sensor spatial resolution.

  20. Coherent lidar imaging of dust clouds: waveform comparison with the poly-phase (P4) modulation waveform

    NASA Astrophysics Data System (ADS)

    Youmans, Douglas G.

    2008-04-01

    A dust or aerosol cloud represents a convenient target to examine the capabilities of range-resolved Doppler and intensity (RRDI) or inverse synthetic aperture ladar (ISAR) imaging coherent laser radar, known as coherent "lidar" for optically thin targets. The poly-phase P4 ladar waveform and its RRDI images are described and compared with previous pulse-burst, linear-FM chirp pulse-compression, pseudo-random phase modulation waveforms, and several other waveforms which have not been utilized to date. A "dust cloud" has very many independently moving point scatterers with velocities that are approximately Gaussian randomly distributed in x,y,z with standard deviations of about 10% of the mean wind + aerosol velocity. This is contrary to a hard-target where the point scatterers are rigidly attached and moving together. The dust cloud produced speckle effects for the various ladar waveforms are compared. In addition, a reference set of four corner-cube retro-reflectors within the dust cloud further illustrates the differences in the various waveform capabilities and resolution.

  1. Basic research planning in mathematical pattern recognition and image analysis

    NASA Technical Reports Server (NTRS)

    Bryant, J.; Guseman, L. F., Jr.

    1981-01-01

    Fundamental problems encountered while attempting to develop automated techniques for applications of remote sensing are discussed under the following categories: (1) geometric and radiometric preprocessing; (2) spatial, spectral, temporal, syntactic, and ancillary digital image representation; (3) image partitioning, proportion estimation, and error models in object scene interference; (4) parallel processing and image data structures; and (5) continuing studies in polarization; computer architectures and parallel processing; and the applicability of "expert systems" to interactive analysis.

  2. Data management in pattern recognition and image processing systems

    NASA Technical Reports Server (NTRS)

    Zobrist, A. L.; Bryant, N. A.

    1976-01-01

    Data management considerations are important to any system which handles large volumes of data or where the manipulation of data is technically sophisticated. A particular problem is the introduction of image-formatted files into the mainstream of data processing application. This report describes a comprehensive system for the manipulation of image, tabular, and graphical data sets which involve conversions between the various data types. A key characteristic is the use of image processing technology to accomplish data management tasks. Because of this, the term 'image-based information system' has been adopted.

  3. Assessing geoaccuracy of structure from motion point clouds from long-range image collections

    NASA Astrophysics Data System (ADS)

    Nilosek, David; Walvoord, Derek J.; Salvaggio, Carl

    2014-11-01

    Automatically extracted and accurate scene structure generated from airborne platforms is a goal of many applications in the photogrammetry, remote sensing, and computer vision fields. This structure has traditionally been extracted automatically through the structure-from-motion (SfM) workflows. Although this process is very powerful, the analysis of error in accuracy can prove difficult. Our work presents a method of analyzing the georegistration error from SfM derived point clouds that have been transformed to a fixed Earth-based coordinate system. The error analysis is performed using synthetic airborne imagery which provides absolute truth for the ray-surface intersection of every pixel in every image. Three methods of georegistration are assessed; (1) using global positioning system (GPS) camera centers, (2) using pose information directly from on-board navigational instrumentation, and (3) using a recently developed method that utilizes the forward projection function and SfM-derived camera pose estimates. It was found that the georegistration derived from GPS camera centers and the direct use of pose information from on-board navigational instruments is very sensitive to noise from both the SfM process and instrumentation. The georegistration transform computed using the forward projection function and the derived pose estimates prove to be far more robust to these errors.

  4. Radio and X-ray images of the SNR G18.8+0.3 interacting with molecular clouds

    NASA Astrophysics Data System (ADS)

    Tian, W. W.; Leahy, D. A.; Wang, Q. D.

    2007-11-01

    New HI images from the VLA Galactic Plane Survey (VGPS) show clear absorption features associated with the supernova remnant (SNR) G18.8+0.3. High-resolution 13CO images reveal that molecular clouds overlap the radio filaments of G18.8+0.3. The 13CO emission spectrum over the full velocity range in the direction of G18.8+0.3 shows two molecular components with high brightness-temperature and three molecular components with low brightness-temperature, all with respective HI absorption. This implies that these clouds are in front of G18.8+0.3. In the HI images, the highest velocity absorption feature seen against the continuum image of G18.8+0.3 is at 129 km s-1, which corresponds to the tangent point in this direction. This yields a lower distance limit of 6.9 kpc for G18.8+0.3. Absence of absorption at negative velocities gives an upper distance limit of 15 kpc. The broadened profile at 205 km s-1 in the 13CO emission spectra is a strong indicator of a possible SNR/CO cloud interaction. Thus, G18.8+0.3 is likely to be at the distance of about 12 kpc. The upper mass limit and mean density of the giant CO cloud at 20 5 km s-1 are ~6 105 M? and ~2 102 cm-3. We find an atomic hydrogen column density in front of G18.8+0.3 of N_HI 21022 cm-2. The ROSAT PSPC observations show a diffuse X-ray enhancement apparently associated with part of the radio shell of G18.8+0.3. Assuming an association, the unabsorbed flux is 2.2 10-12 erg cm-2 s-1, suggesting an intrinsic luminosity of 3.6 1034 erg s-1 for G18.8+0.3.

  5. Study of active millimeter-wave image speckle reduction by Hadamard phase pattern illumination.

    PubMed

    Koers, Gaetan; Ocket, Ilja; Feng, Qi; Tavakol, Vahid; Jger, Irina; Nauwelaers, Bart; Stiens, Johan

    2008-02-01

    Active millimeter-wave images typically exhibit characteristic speckle noise, due to the coherence of artificial millimeter-wave sources. We study the Hadamard speckle contrast reduction (SCR) technique, which has been successfully used in laser projection systems, in the context of millimeter-wave imaging. We show the impact of Hadamard pattern order and size and of image and pattern resolution on speckle reduction efficiency. Practical limitations of Hadamard pattern implementations and their effect on speckle reduction efficiency are also discussed. PMID:18246164

  6. Convolution Comparison Pattern: An Efficient Local Image Descriptor for Fingerprint Liveness Detection.

    PubMed

    Gottschlich, Carsten

    2016-01-01

    We present a new type of local image descriptor which yields binary patterns from small image patches. For the application to fingerprint liveness detection, we achieve rotation invariant image patches by taking the fingerprint segmentation and orientation field into account. We compute the discrete cosine transform (DCT) for these rotation invariant patches and attain binary patterns by comparing pairs of two DCT coefficients. These patterns are summarized into one or more histograms per image. Each histogram comprises the relative frequencies of pattern occurrences. Multiple histograms are concatenated and the resulting feature vector is used for image classification. We name this novel type of descriptor convolution comparison pattern (CCP). Experimental results show the usefulness of the proposed CCP descriptor for fingerprint liveness detection. CCP outperforms other local image descriptors such as LBP, LPQ and WLD on the LivDet 2013 benchmark. The CCP descriptor is a general type of local image descriptor which we expect to prove useful in areas beyond fingerprint liveness detection such as biological and medical image processing, texture recognition, face recognition and iris recognition, liveness detection for face and iris images, and machine vision for surface inspection and material classification. PMID:26844544

  7. Convolution Comparison Pattern: An Efficient Local Image Descriptor for Fingerprint Liveness Detection

    PubMed Central

    Gottschlich, Carsten

    2016-01-01

    We present a new type of local image descriptor which yields binary patterns from small image patches. For the application to fingerprint liveness detection, we achieve rotation invariant image patches by taking the fingerprint segmentation and orientation field into account. We compute the discrete cosine transform (DCT) for these rotation invariant patches and attain binary patterns by comparing pairs of two DCT coefficients. These patterns are summarized into one or more histograms per image. Each histogram comprises the relative frequencies of pattern occurrences. Multiple histograms are concatenated and the resulting feature vector is used for image classification. We name this novel type of descriptor convolution comparison pattern (CCP). Experimental results show the usefulness of the proposed CCP descriptor for fingerprint liveness detection. CCP outperforms other local image descriptors such as LBP, LPQ and WLD on the LivDet 2013 benchmark. The CCP descriptor is a general type of local image descriptor which we expect to prove useful in areas beyond fingerprint liveness detection such as biological and medical image processing, texture recognition, face recognition and iris recognition, liveness detection for face and iris images, and machine vision for surface inspection and material classification. PMID:26844544

  8. Improving Cloud Detection in Satellite Images of Coral Reef Environments Using Space Shuttle Photographs and High-Definition Television

    NASA Technical Reports Server (NTRS)

    Andrefeouet, Serge; Robinson, Julie

    2000-01-01

    Coral reefs worldwide are suffering from severe and rapid degradation (Bryant et A, 1998; Hoegh-Guldberg, 1999). Quick, consistent, large-scale assessment is required to assess and monitor their status (e.g., USDOC/NOAA NESDIS et al., 1999). On-going systematic collection of high resolution digital satellite data will exhaustively complement the relatively small number of SPOT, Landsat 4-5, and IRS scenes acquired for coral reefs the last 20 years. The workhorse for current image acquisition is the Landsat 7 ETM+ Long Term Acquisition Plan (Gasch et al. 2000). Coral reefs are encountered in tropical areas and cloud contamination in satellite images is frequently a problem (Benner and Curry 1998), despite new automated techniques of cloud cover avoidance (Gasch and Campana 2000). Fusion of multidate acquisitions is a classical solution to solve the cloud problems. Though elegant, this solution is costly since multiple images must be purchased for one location; the cost may be prohibitive for institutions in developing countries. There are other difficulties associated with fusing multidate images as well. For example, water quality or surface state can significantly change through time in coral reef areas making the bathymetric processing of a mosaiced image strenuous. Therefore, another strategy must be selected to detect clouds and improve coral reefs mapping. Other supplemental data could be helpful and cost-effective for distinguishing clouds and generating the best possible reef maps in the shortest amount of time. Photographs taken from the 1960s to the present from the Space Shuttle and other human-occupied spacecraft are one under-used source of alternative multitemporal data (Lulla et al. 1996). Nearly 400,000 photographs have been acquired during this period, an estimated 28,000 of these taken to date are of potential value for reef remote sensing (Robinson et al. 2000a). The photographic images can be digitized into three bands (red, green and blue) and processed for various applications (e.g., Benner and Curry 1998, Nedeltchev 1999, Glasser and Lulla 2000, Robinson et al. 2000c, Webb et al, in press).

  9. UV contrasts and microphysical properties of the upper clouds of Venus from the UV and NIR VMC/VEx images

    NASA Astrophysics Data System (ADS)

    Petrova, Elena V.; Shalygina, Oksana S.; Markiewicz, Wojciech J.

    2015-11-01

    The nature of UV contrasts observed on the upper cloud deck of Venus is still not known. To constrain better the properties of particles that may cause the UV contrasts, the phase dependences of brightness of the venusian clouds measured by the ultraviolet and near-infrared channels of the Venus Express Venus Monitoring Camera (VMC) in the UV dark and bright regions are jointly analyzed. The range of small phase angles, where the glory phenomenon is observed, is of key importance, since the properties of cloud particles can be reliably estimated from the shape and position of glory. However, from more than 2500 orbits of the mission, only in ten orbits the images were taken simultaneously in UV and near-IR channels at small phase angles. Their analysis have yielded the following results. In the UV dark and bright clouds of the equatorial region near the local noon, the derived radii of cloud particles turned out to be the same and rather large, 1.3-1.6 μm. No unambiguous connection between the UV contrasts and the brightness in the near-IR channel was found. In some cases, the regions that appear contrasting in UV show no difference in the near-IR brightness. This means that the properties of 1-μm mode particles are the same in these regions and only the contribution of small submicron particles differs, because the near-IR channel is weakly sensitive to the presence of particles smaller than ≈0.3 μm in radius. The difference in the composition of 10% of the number of submicron particles (if sulfur and sulfuric acid compositions are considered as probable for the submicron mode) is enough to produce the observed UV contrasts. In the other cases, the UV contrasts are accompanied by the differences in near-IR brightness. This suggests that the cloud particles of the 1-μm mode contribute to these contrasts as well. However, the modeling showed that exactly the variations in the composition of submicron particles in the clouds produce a key effect on the UV contrasts observed. Moreover, a portion of submicron particles with a high refractive index, when incorporated into the sulfuric acid aerosols during the condensation process, may provide the higher refractive index (relative to that of sulfuric acid) of the 1-μm mode derived from modeling. The glory phenomenon was also observed at latitudes 30-60°S, in the transition region from the mottled clouds in dark tropics to streaky cloud morphology at higher latitudes. This allowed the sizes of cloud particles near the frequently seen UV-bright bands to be estimated. It was found that the radii of particles in the upper cloud layer decrease from 1.05-1.2 to 0.8-0.9 μm with increasing latitude from ∼35°S to ∼62°S. Our present modeling also clearly showed that the high brightness in the UV-bright band is caused by an additional amount of non-absorbing (in UV) particles with Reff ≈ 0.9 μm at the cloud top and/or by the decrease of a portion of absorbing particles inside the clouds below this layer. No variations of the effect with the local solar time for the interval from 10 to 13 h available in the data were detected.

  10. Speckle reduction in THz imaging systems with multiple phase patterns

    NASA Astrophysics Data System (ADS)

    Jaeger, Irina; Stiens, Johan; Koers, Gaetan; Poesen, Gert; Vounckx, Roger

    2006-04-01

    THz technology makes possible imaging of phenomena, inaccessible to both visible and infrared radiation, but the imaging is still in its early stages of development. This paper draws attention to the aspects of speckle reduction to improve the image quality. Because all existing THz sources are coherent - speckle is an ultimate limiting factor of the free-space imaging techniques. Speckle arises when coherent light scattered from a rough surface is detected by an intensity detector with a finite aperture, hiding the image information. This problem is of special importance for THz imaging, because surface roughness is closer to the object dimension as in optical imaging. The reduction of speckle is highly desirable and we propose here a Hadamard matrix solution. Hadamard diffuser for mm-wave frequency range have been designed, built and tested. We report 50% speckle reduction measurements using a free-space vector network analyzer over the full W-band (75-110 GHz). The advantage of the mm-wave Hadamard technology over optical: the diffuser doesn't have to be moved (vibrated) any more to accomplish the technology of speckle reduction. Temporal optical effect is substituted here by spatial quasi-optical: Hadamard coding in each scan pixel. Second method delivers realistic system parameters for the speckle reduction with polychromatic light for aviation security.

  11. Pixel patterns for voxels in a contact-type three-dimensional imaging system for full-parallax image display

    SciTech Connect

    Son, Jung-Young; Saveljev, Vladmir V.; Javidi, Bahram; Kim, Dae-Sik; Park, Min-Chul

    2006-06-20

    Incomplete voxels, which can be seen only at a part of the viewing zone's cross section in the optical configuration of a full parallax multiview imaging system based on a two-dimensional point light source array, are identified. Their corresponding pixel patterns are found to maximize the space where the voxels can exist in the configuration and to increase the voxel resolution of the displayable three-dimensional images. Furthermore, the pixel patterns for the rhomb-shaped pixel cells are also defined, and some problems related to voxel-based image synthesis are discussed.

  12. Multi-Scale Fractal Analysis of Image Texture and Pattern

    NASA Technical Reports Server (NTRS)

    Emerson, Charles W.; Quattrochi, Dale A.; Luvall, Jeffrey C.

    1997-01-01

    Fractals embody important ideas of self-similarity, in which the spatial behavior or appearance of a system is largely scale-independent. Self-similarity is a property of curves or surfaces where each part is indistinguishable from the whole. The fractal dimension D of remote sensing data yields quantitative insight on the spatial complexity and information content contained within these data. Analyses of Normalized Difference Vegetation Index (NDVI) images of homogeneous land covers near Huntsville, Alabama revealed that the fractal dimension of an image of an agricultural land cover indicates greater complexity as pixel size increases, a forested land cover gradually grows smoother, and an urban image remains roughly self-similar over the range of pixel sizes analyzed(l0 to 80 meters). The forested scene behaves as one would expect-larger pixel sizes decrease the complexity of the image as individual clumps of trees are averaged into larger blocks. The increased complexity of the agricultural image with increasing pixel size results from the loss of homogeneous groups of pixels in the large fields to mixed pixels composed of varying combinations of NDVI values that correspond to roads and vegetation. The same process occur's in the urban image to some extent, but the lack of large, homogeneous areas in the high resolution NDVI image means the initially high D value is maintained as pixel size increases. The slope of the fractal dimension-resolution relationship provides indications of how image classification or feature identification will be affected by changes in sensor resolution.

  13. Content based image retrieval using local binary pattern operator and data mining techniques.

    PubMed

    Vatamanu, Oana Astrid; Frandeş, Mirela; Lungeanu, Diana; Mihalaş, Gheorghe-Ioan

    2015-01-01

    Content based image retrieval (CBIR) concerns the retrieval of similar images from image databases, using feature vectors extracted from images. These feature vectors globally define the visual content present in an image, defined by e.g., texture, colour, shape, and spatial relations between vectors. Herein, we propose the definition of feature vectors using the Local Binary Pattern (LBP) operator. A study was performed in order to determine the optimum LBP variant for the general definition of image feature vectors. The chosen LBP variant is then subsequently used to build an ultrasound image database, and a database with images obtained from Wireless Capsule Endoscopy. The image indexing process is optimized using data clustering techniques for images belonging to the same class. Finally, the proposed indexing method is compared to the classical indexing technique, which is nowadays widely used. PMID:25991105

  14. Remote sensing of cloud droplet size distributions in DC3 with the UMBC-LACO Rainbow Polarimetric Imager (RPI)

    NASA Astrophysics Data System (ADS)

    Buczkowski, S.; Martins, J.; Fernandez-Borda, R.; Cieslak, D.; Hall, J.

    2013-12-01

    The UMBC Rainbow Polarimetric Imager is a small form factor VIS imaging polarimeter suitable for use on a number of platforms. An optical system based on a Phillips prism with three Bayer filter color detectors, each detecting a separate polarization state, allows simultaneous detection of polarization and spectral information. A Mueller matrix-like calibration scheme corrects for polarization artifacts in the optical train and allows retrieval of the polarization state of incoming light to better than 0.5%. Coupled with wide field of view optics (~90°), RPI can capture images of cloudbows over a wide range of aircraft headings and solar zenith angles for retrieval of cloud droplet size distribution (DSD) parameters. In May-June 2012, RPI was flown in a nadir port on the NASA DC-8 during the DC3 field campaign. We will show examples of cloudbow DSD parameter retrievals from the campaign to demonstrate the efficacy of such a system to terrestrial atmospheric remote sensing. RPI image from DC3 06/15/2012 flight. Left panel is raw image from the RPI 90° camera. Middle panel is Stokes 'q' parameter retrieved from full three camera dataset. Right panel is a horizontal cut in 'q' through the glory. Both middle and right panels clearly show cloudbow features which can be fit to infer cloud DSD parameters.

  15. Milliarcsecond imaging of clumpy dust clouds in the red giant L2 Pup with the Very Large Telescope Interferometer

    NASA Astrophysics Data System (ADS)

    Ohnaka, K.; Schertl, D.; Hofmann, K. H.; Weigelt, G.

    2014-04-01

    Despite its importance in mass loss, the dust formation in AGB stars is not yet understood well. There is growing evidence that the dust envelopes of AGB stars are much more complex--clumpy and/or bipolar--than spherically expanding shells. The non-spherical structures emerging in AGB stars may be the seed of asymmetry in planetary nebulae. However, direct observations of the clumpy dust cloud formation close to the star is difficult, because we need milliarcsecond spatial resolution. We present milliarcsecond resolution near-IR imaging of the bright, nearby M giant L2 Pup. The 2.2 micron image taken with VLT/NACO at a spatial resolution of 54 mas shows an asymmetric circumstellar envelope with 300 x 200 mas (12 x 8 stellar radii), elongated in East-West direction. Furthermore, we succeeded in aperture-synthesis imaging of L2 Pup by combining these single-dish VLT/NACO data with near-IR interferometric data taken with the AMBER instrument at the Very Large Telescope Interferometer. The reconstructed image with a spatial resolution of 12 mas shows two clumps at 20--30 mas away from the star, as well as another clump over the stellar. This is the first imaging of clumpy dust clouds toward L2 Pup, whose presence was only inferred from polarimetric and photometric observations. Our observations reveal the clumpy dust formation close to the star, at 1.5--2.5 stellar radii.

  16. Cloud screening and quality control algorithm for star photometer data: assessment with lidar measurements and with all-sky-images

    NASA Astrophysics Data System (ADS)

    Prez-Ramrez, D.; Lyamani, H.; Olmo, F. J.; Whiteman, D. N.; Navas-Guzman, F.; Alados-Arboledas, L.

    2012-02-01

    This paper present the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. This kind of algorithms is necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, ?Ae(?), and precipitable water vapor content, W, at night-time. This cloud screening procedure consists of calculating moving averages of ?Ae(?) and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable ?Ae(?) and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16 N, 3.60 W, 680 m a.s.l.; South-East of Spain) for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  17. Cloud screening and quality control algorithm for star photometer data: assessment with lidar measurements and with all-sky images

    NASA Astrophysics Data System (ADS)

    Prez-Ramrez, D.; Lyamani, H.; Olmo, F. J.; Whiteman, D. N.; Navas-Guzmn, F.; Alados-Arboledas, L.

    2012-07-01

    This paper presents the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. These algorithms are necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, ?Ae(?), and precipitable water vapor content, W, at nighttime. This cloud screening procedure consists of calculating moving averages of ?Ae(?) and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable ?Ae(?) and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16 N, 3.60 W, 680 m a.s.l.; South-East of Spain) for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  18. Cloud Screening and Quality Control Algorithm for Star Photometer Data: Assessment with Lidar Measurements and with All-sky Images

    NASA Technical Reports Server (NTRS)

    Ramirez, Daniel Perez; Lyamani, H.; Olmo, F. J.; Whiteman, D. N.; Navas-Guzman, F.; Alados-Arboledas, L.

    2012-01-01

    This paper presents the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. These algorithms are necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, delta Ae(lambda), and precipitable water vapor content, W, at nighttime. This cloud screening procedure consists of calculating moving averages of delta Ae() and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable Ae(lambda) and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16 N, 3.60 W, 680 ma.s.l.; South-East of Spain) for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  19. Proceedings of the NASA Symposium on Mathematical Pattern Recognition and Image Analysis

    NASA Technical Reports Server (NTRS)

    Guseman, L. F., Jr.

    1983-01-01

    The application of mathematical and statistical analyses techniques to imagery obtained by remote sensors is described by Principal Investigators. Scene-to-map registration, geometric rectification, and image matching are among the pattern recognition aspects discussed.

  20. Automatic recognition of coded-pattern sequence by using image cross-correlation

    NASA Astrophysics Data System (ADS)

    Zhong, Sidong; Gao, Zhi

    2005-12-01

    In order to solve the problem of automatic target recognition in photogrammetry, a method of recognition for coded-pattern sequence by using image cross-correlation is presented. Coded-pattern sequences are a series of patterns that posses unique identification information, which will be extracted to realize recognition. The concrete operation is to do cross-correlation of the real pattern image and the fictitious templet image of every possible pattern. The basis of this method is the theory of signal processing that the operation of cross-correlation can detect the resemblance of signals with different offset. The result of experiment shows that this method is applicable in many situations and also has the characteristics of high accuracy and high speed.

  1. Two Levels Fusion Decision for Multispectral Image Pattern Recognition

    NASA Astrophysics Data System (ADS)

    Elmannai, H.; Loghmari, M. A.; Naceur, M. S.

    2015-10-01

    Major goal of multispectral data analysis is land cover classification and related applications. The dimension drawback leads to a small ratio of the remote sensing training data compared to the number of features. Therefore robust methods should be associated to overcome the dimensionality curse. The presented work proposed a pattern recognition approach. Source separation, feature extraction and decisional fusion are the main stages to establish an automatic pattern recognizer. The first stage is pre-processing and is based on non linear source separation. The mixing process is considered non linear with gaussians distributions. The second stage performs feature extraction for Gabor, Wavelet and Curvelet transform. Feature information presentation provides an efficient information description for machine vision projects. The third stage is a decisional fusion performed in two steps. The first step assign the best feature to each source/pattern using the accuracy matrix obtained from the learning data set. The second step is a source majority vote. Classification is performed by Support Vector Machine. Experimentation results show that the proposed fusion method enhances the classification accuracy and provide powerful tool for pattern recognition.

  2. Resolution analysis in computational imaging with patterned illumination and bucket detection.

    PubMed

    Rodrguez, A D; Clemente, P; Irles, E; Tajahuerce, E; Lancis, J

    2014-07-01

    In computational imaging by pattern projection, a sequence of microstructured light patterns codified onto a programmable spatial light modulator is used to sample an object. The patterns are used as generalized measurement modes where the object information is expressed. In this Letter, we show that the resolution of the recovered image is only limited by the numerical aperture of the projecting optics regardless of the quality of the collection optics. We provide proof-of-principle experiments where the single-pixel detection strategy outperforms the resolution achieved using a conventional optical array detector for optical imaging. It is advantageous in the presence of real-world conditions, such as optical aberrations and optical imperfections in between the sample and the sensor. We provide experimental verification of image retrieval even when an optical diffuser prevents imaging with a megapixel array camera. PMID:24978763

  3. Semantic Concept Co-Occurrence Patterns for Image Annotation and Retrieval.

    PubMed

    Feng, Linan; Bhanu, Bir

    2016-04-01

    Describing visual image contents by semantic concepts is an effective and straightforward way to facilitate various high level applications. Inferring semantic concepts from low-level pictorial feature analysis is challenging due to the semantic gap problem, while manually labeling concepts is unwise because of a large number of images in both online and offline collections. In this paper, we present a novel approach to automatically generate intermediate image descriptors by exploiting concept co-occurrence patterns in the pre-labeled training set that renders it possible to depict complex scene images semantically. Our work is motivated by the fact that multiple concepts that frequently co-occur across images form patterns which could provide contextual cues for individual concept inference. We discover the co-occurrence patterns as hierarchical communities by graph modularity maximization in a network with nodes and edges representing concepts and co-occurrence relationships separately. A random walk process working on the inferred concept probabilities with the discovered co-occurrence patterns is applied to acquire the refined concept signature representation. Through experiments in automatic image annotation and semantic image retrieval on several challenging datasets, we demonstrate the effectiveness of the proposed concept co-occurrence patterns as well as the concept signature representation in comparison with state-of-the-art approaches. PMID:26959678

  4. Imaging polychromator for density measurements of polystyrene pellet cloud on the Large Helical Device.

    PubMed

    Sharov, I A; Sergeev, V Yu; Miroshnikov, I V; Tamura, N; Kuteev, B V; Sudo, S

    2015-04-01

    Experimental data on spatial distributions of a pellet cloud electron density are necessary for the development of many applications of pellet injection, namely, plasma fuelling, discharge control, and plasma diagnostics. An improved approach of electron density measurements inside the cloud of a polystyrene pellet ablating in hot plasma of the large helical device is described. Density values of (1-30) 10(16) cm(-3) depending on the background plasma parameters and distance from the solid pellet were measured. PMID:25933860

  5. Imaging polychromator for density measurements of polystyrene pellet cloud on the Large Helical Device

    NASA Astrophysics Data System (ADS)

    Sharov, I. A.; Sergeev, V. Yu.; Miroshnikov, I. V.; Tamura, N.; Kuteev, B. V.; Sudo, S.

    2015-04-01

    Experimental data on spatial distributions of a pellet cloud electron density are necessary for the development of many applications of pellet injection, namely, plasma fuelling, discharge control, and plasma diagnostics. An improved approach of electron density measurements inside the cloud of a polystyrene pellet ablating in hot plasma of the large helical device is described. Density values of (1-30) 1016 cm-3 depending on the background plasma parameters and distance from the solid pellet were measured.

  6. Cloud image retrieval and characterization using ground-based dual-wavelength radar at millimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Colon-Diaz, Nivia; Cruz-Pol, Sandra L.; Sekelsky, Stephen M.

    2003-04-01

    Characterization of the microphysical properties of non-precipitating stratus clouds including their suspended-water droplet size distribution and the cloud's liquid water content are estimated in this work. The dual wavelength ratio, DWR, and the differential extinction, DE, were computed at two millimeter frequencies, 33 GHz and 95 GHz, using UMass Cloud Profiling Radar System (CPRS) to estimate the drop size distribution. Data from radiosonde observations (Raob) is used as input in a recently calibrated model for estimation of the gaseous attenuation at Ka.-band and Liebe's model at W-band. Integrated specific humidity from a radiometer is used to constrain the radiosonde specific humidity. The radar reflectivity is corrected to take into account the effect of the wind speed, the difference of beamwidth at both frequencies and the difference in sampled range cells. Radar reflectivity and ancillary data are combined to obtain the differential extinction and the estimated cloud's liquid water density. Profiles of the processed data, such as DE, the DWR and the cloud's liquid water density are presented. Cloud's water density and radar reflectivity were used for the size distribution estimation of the suspended water droplets and the median drop diameter.

  7. A comparison of performance of automatic cloud coverage assessment algorithm for Formosat-2 image using clustering-based and spatial thresholding methods

    NASA Astrophysics Data System (ADS)

    Hsu, Kuo-Hsien

    2012-11-01

    Formosat-2 image is a kind of high-spatial-resolution (2 meters GSD) remote sensing satellite data, which includes one panchromatic band and four multispectral bands (Blue, Green, Red, near-infrared). An essential sector in the daily processing of received Formosat-2 image is to estimate the cloud statistic of image using Automatic Cloud Coverage Assessment (ACCA) algorithm. The information of cloud statistic of image is subsequently recorded as an important metadata for image product catalog. In this paper, we propose an ACCA method with two consecutive stages: preprocessing and post-processing analysis. For pre-processing analysis, the un-supervised K-means classification, Sobel's method, thresholding method, non-cloudy pixels reexamination, and cross-band filter method are implemented in sequence for cloud statistic determination. For post-processing analysis, Box-Counting fractal method is implemented. In other words, the cloud statistic is firstly determined via pre-processing analysis, the correctness of cloud statistic of image of different spectral band is eventually cross-examined qualitatively and quantitatively via post-processing analysis. The selection of an appropriate thresholding method is very critical to the result of ACCA method. Therefore, in this work, We firstly conduct a series of experiments of the clustering-based and spatial thresholding methods that include Otsu's, Local Entropy(LE), Joint Entropy(JE), Global Entropy(GE), and Global Relative Entropy(GRE) method, for performance comparison. The result shows that Otsu's and GE methods both perform better than others for Formosat-2 image. Additionally, our proposed ACCA method by selecting Otsu's method as the threshoding method has successfully extracted the cloudy pixels of Formosat-2 image for accurate cloud statistic estimation.

  8. Genetic Algorithm-Based Relevance Feedback for Image Retrieval Using Local Similarity Patterns.

    ERIC Educational Resources Information Center

    Stejic, Zoran; Takama, Yasufumi; Hirota, Kaoru

    2003-01-01

    Proposes local similarity pattern (LSP) as a new method for computing digital image similarity. Topics include optimizing similarity computation based on genetic algorithm; relevance feedback; and an evaluation of LSP on five databases that showed an increase in retrieval precision over other methods for computing image similarity. (Author/LRW)

  9. Cloud Computing for radiologists.

    PubMed

    Kharat, Amit T; Safvi, Amjad; Thind, Ss; Singh, Amarjit

    2012-07-01

    Cloud computing is a concept wherein a computer grid is created using the Internet with the sole purpose of utilizing shared resources such as computer software, hardware, on a pay-per-use model. Using Cloud computing, radiology users can efficiently manage multimodality imaging units by using the latest software and hardware without paying huge upfront costs. Cloud computing systems usually work on public, private, hybrid, or community models. Using the various components of a Cloud, such as applications, client, infrastructure, storage, services, and processing power, Cloud computing can help imaging units rapidly scale and descale operations and avoid huge spending on maintenance of costly applications and storage. Cloud computing allows flexibility in imaging. It sets free radiology from the confines of a hospital and creates a virtual mobile office. The downsides to Cloud computing involve security and privacy issues which need to be addressed to ensure the success of Cloud computing in the future. PMID:23599560

  10. Cloud Computing for radiologists

    PubMed Central

    Kharat, Amit T; Safvi, Amjad; Thind, SS; Singh, Amarjit

    2012-01-01

    Cloud computing is a concept wherein a computer grid is created using the Internet with the sole purpose of utilizing shared resources such as computer software, hardware, on a pay-per-use model. Using Cloud computing, radiology users can efficiently manage multimodality imaging units by using the latest software and hardware without paying huge upfront costs. Cloud computing systems usually work on public, private, hybrid, or community models. Using the various components of a Cloud, such as applications, client, infrastructure, storage, services, and processing power, Cloud computing can help imaging units rapidly scale and descale operations and avoid huge spending on maintenance of costly applications and storage. Cloud computing allows flexibility in imaging. It sets free radiology from the confines of a hospital and creates a virtual mobile office. The downsides to Cloud computing involve security and privacy issues which need to be addressed to ensure the success of Cloud computing in the future. PMID:23599560

  11. Misleading FLAIR imaging pattern after glioma surgery with intraoperative MRI.

    PubMed

    Lescher, Stephanie; Jurcoane, Alina; Schniewindt, Sonja; Senft, Christian; Hattingen, Elke

    2016-01-01

    Intraoperative MRI (iMRI) allows a more detailed appreciation of the extent of resection than does conventional neurosurgery and results in longer overall survival in patients with malignant glioma. However, it is unknown whether the intraoperative application of contrast agent influences the early postsurgical MRI. The preceding iMRI could alter the signals of MR sequences in the early postsurgical MRI, especially in sequences influenced by T1 contrast. Hereby, we investigate such iMRI-induced influences on the fluid-attenuated inversion recovery (FLAIR) sequence. We retrospectively analyzed postsurgical T2w, T1w, and FLAIR images by visual inspection and by signal measurements in 46 patients with malignant gliomas after tumor resection. Of these, n?=?25 patients were operated with conventional microsurgery, and n?=?21 patients were operated with contrast-enhanced iMRI-guided microsurgery. We measured signal intensity in the resection cavity, in the cerebrospinal fluid (CSF) of the ventricles, and in the normal brain tissue contralateral to the tumor-bearing hemisphere on axial FLAIR images and T1-weighted and T2-weighted images. In 18 patients, the FLAIR sequence revealed hyperintense signal changes of the CSF in the subarachnoid or ventricular spaces. Seventeen of these 18 patients had received intraoperative MRI. In both FLAIR and T1-weighted images, the signal of the CSF in the ventricles was significantly higher in patients with iMRI than in patients without iMRI. The intraoperative application of contrast agent that is used for iMRI significantly influences postsurgical MRI within the first 72h. We found hyperintense signal changes of the CSF in the FLAIR sequence in the subarachnoid and intraventricular spaces mimicking subarachnoid hemorrhage. The findings may result in a misdiagnosis of subarachnoid hemorrhage (SAH) in these patients. PMID:26201972

  12. Automatic Assessment and Reduction of Noise using Edge Pattern Analysis in Non-Linear Image Enhancement

    NASA Technical Reports Server (NTRS)

    Jobson, Daniel J.; Rahman, Zia-Ur; Woodell, Glenn A.; Hines, Glenn D.

    2004-01-01

    Noise is the primary visibility limit in the process of non-linear image enhancement, and is no longer a statistically stable additive noise in the post-enhancement image. Therefore novel approaches are needed to both assess and reduce spatially variable noise at this stage in overall image processing. Here we will examine the use of edge pattern analysis both for automatic assessment of spatially variable noise and as a foundation for new noise reduction methods.

  13. Imaging outside the box: Resolution enhancement in X-ray coherent diffraction imaging by extrapolation of diffraction patterns

    NASA Astrophysics Data System (ADS)

    Latychevskaia, Tatiana; Chushkin, Yuriy; Zontone, Federico; Fink, Hans-Werner

    2015-11-01

    Coherent diffraction imaging is a high-resolution imaging technique whose potential can be greatly enhanced by applying the extrapolation method presented here. We demonstrate the enhancement in resolution of a non-periodical object reconstructed from an experimental X-ray diffraction record which contains about 10% missing information, including the pixels in the center of the diffraction pattern. A diffraction pattern is extrapolated beyond the detector area and as a result, the object is reconstructed at an enhanced resolution and better agreement with experimental amplitudes is achieved. The optimal parameters for the iterative routine and the limits of the extrapolation procedure are discussed.

  14. Patterns of Hepatosplenic Brucella Abscesses on Cross-Sectional Imaging: A Review of Clinical and Imaging Features.

    PubMed

    Heller, Tom; Bélard, Sabine; Wallrauch, Claudia; Carretto, Edoardo; Lissandrin, Raffaella; Filice, Carlo; Brunetti, Enrico

    2015-10-01

    While diffuse involvement of liver and spleen is frequently seen in brucellosis, suppurative abscesses caused by Brucella are less common but well described. With the increased availability of cross-sectional imaging techniques, reports have become more frequent. Four patients with hepatosplenic abscesses caused by Brucella spp. are described and included in a review of 115 previously published cases. Clinical characteristics and patterns on ultrasound (US) and computed tomography imaging were analyzed. Furthermore, the proportion of patients with brucellosis affected by suppurative hepatosplenic lesions was estimated. Hepatosplenic abscesses were seen in 1.2% of patients with brucellosis and were mostly caused by Brucella melitensis. Imaging analysis revealed two main distinct patterns. Solitary abscesses involving liver more frequently than spleen, and showing characteristic central calcifications, characterize the first pattern. Multiple smaller abscesses, frequent spleen involvement, and absence of calcifications characterize the second pattern. Blood and aspirate cultures were frequently negative, however, the positivity rate increased over the past years. Indirect Coombs test was positive in 96%. Half of the patients were cured by antibiotic treatment; case fatality in this series was 1.9%. Hepatosplenic abscesses due to Brucella infections have characteristic imaging findings. Clinicians should be aware of these and the proactive use of cross-sectional imaging, particularly US, should be encouraged in endemic regions. PMID:26283749

  15. Development of microscale pattern for digital image correlation up to 1400 °C

    NASA Astrophysics Data System (ADS)

    Dong, Yali; Kakisawa, Hideki; Kagawa, Yutaka

    2015-05-01

    Speckle patterns to be used for digital image correlation (DIC) at the micrometer level up to 1400 °C were fabricated by several methods. The quality of the patterns before and after heating was evaluated in terms of the mean intensity gradient (MIG) and the speckle size distribution. The displacement accuracy in simulative translation of images showed that the MIG alone was not enough to evaluate the pattern properties; a large MIG, an even speckle size distribution, and a wide speckle size range pattern were required for a good DIC. The reaction between the patterning material and substrate, the cracking of speckles, and the plastic flow of patterning material may cause changes in the pattern morphology at high temperature. Two patterning methods, spraying a mixture of ceramics powder and binder by a fine-nozzle air brush and abrading a polished surface, yielded a small pattern with high MIG values and even size distributions that was stable at 1400 °C. The potential of the fabricated patterns was shown by measuring the coefficient of thermal expansion of polycrystalline Al2O3 from 800 °C to 1400 °C.

  16. Results on atmospheric dynamics at the Venus cloud tops from wind tracking in VMC images

    NASA Astrophysics Data System (ADS)

    Moissl, R.; Khatuntsev, I.; Limaye, S. S.; Titov, D. T.; Markiewicz, W. J.

    2008-09-01

    The upper clouds of Venus have been studied extensively from ground and space borne observations in the past, especially in the ultraviolet part of the spectrum. To date we know that the atmosphere of Venus is in a constant state of super-rotation, reaching speeds around 100 ms-1 at the cloud tops and that the cloud markings in the UV are caused by SO2 and another, yet unknown, UV absorber. This presentation deals with the results on the atmospheric dynamics at the cloud top region (? 65-70 km above the surface) of Venus, derived from manual and automated cloud tracking in the UV channel (lambda= 365 +- 10 nm) of the Venus Monitoring Camera Experiment (VMC) on board the Venus Express mission. With the VMC it became possible to investigate the global dynamics with a relatively high resolution in space and time on a long term basis. In addition to the confirmation of results from previous studies on the atmospheric dynamics, the observations of the southern hemisphere by the VMC allowed for detailed studies of the strong cloud-level super-rotation phenomenon on Venus and its variability on different timescales ranging from hours to several months. Information on the latitudinal wind speed profiles could be obtained for latitudes up to ?85 degree S, extending the results from previous studies by almost 20 degree. Global wave modes which are believed to play a key role for understanding energy transport phenomena in the venusian atmosphere, such as a 4-day Kelvin wave mode in low latitudes and diurnal and semidiurnal solar thermal tides have been detected in the analysis cloud tracked wind fields of the southern hemisphere of Venus.

  17. Attempt of UAV oblique images and MLS point clouds for 4D modelling of roadside pole-like objects

    NASA Astrophysics Data System (ADS)

    Lin, Yi; West, Geoff

    2014-11-01

    The state-of-the-art remote sensing technologies, namely Unmanned Aerial Vehicle (UAV) based oblique imaging and Mobile Laser Scanning (MLS) show great potential for spatial information acquisition. This study investigated the combination of the two data sources for 4D modelling of roadside pole-like objects. The data for the analysis were collected by the Microdrone md4-200 UAV imaging system and the Sensei MLS system developed by the Finnish Geodetic Institute. Pole extraction, 3D structural parameter derivation and texture segmentation were deployed on the oblique images and point clouds, and their results were fused to yield the 4D models for one example of pole-like objects, namely lighting poles. The combination techniques proved promising.

  18. Holographic images of iodine atoms on a silver surface from electron emission patterns

    NASA Astrophysics Data System (ADS)

    Hu, Peijun; King, D. A.

    1991-10-01

    BARTON1 has suggested that photoelectron interference patterns may be used directly as holograms to obtain atomic-resolution images of surface structures. Bulk structures have been obtained previously by this means from experimental patterns of high-energy Kikuchi (quasi-elastically scattered) and Auger electrons2,3. Here we test the feasibility of this technique for determination of surface structures using Auger intensity patterns obtained4,5 from iodine chemisorbed on a pseudomorphic silver monolayer on Pt{111}. By direct numerical holographic inversion, we obtain three-dimensional images which show that iodine adatoms are located in hollows of 3-fold symmetry on the surface. The images yield the site symmetry with good atomic resolution in the surface plane, but suffer from poor resolution along the Ag-I axis. We anticipate that data with better angular resolution obtained at low temperatures would improve the spatial resolution of such images.

  19. Staining Pattern Classification of Antinuclear Autoantibodies Based on Block Segmentation in Indirect Immunofluorescence Images

    PubMed Central

    Li, Jiaqian; Tseng, Kuo-Kun; Hsieh, Zu Yi; Yang, Ching Wen; Huang, Huang-Nan

    2014-01-01

    Indirect immunofluorescence based on HEp-2 cell substrate is the most commonly used staining method for antinuclear autoantibodies associated with different types of autoimmune pathologies. The aim of this paper is to design an automatic system to identify the staining patterns based on block segmentation compared to the cell segmentation most used in previous research. Various feature descriptors and classifiers are tested and compared in the classification of the staining pattern of blocks and it is found that the technique of the combination of the local binary pattern and the k-nearest neighbor algorithm achieve the best performance. Relying on the results of block pattern classification, experiments on the whole images show that classifier fusion rules are able to identify the staining patterns of the whole well (specimen image) with a total accuracy of about 94.62%. PMID:25474260

  20. Integration of Color and Local Derivative Pattern Features for Content-Based Image Indexing and Retrieval

    NASA Astrophysics Data System (ADS)

    Vipparthi, Santosh Kumar; Nagar, Shyam Krishna

    2015-09-01

    This paper presents two new feature descriptors for content based image retrieval (CBIR) application. The proposed two descriptors are named as color local derivative patterns (CLDP) and inter color local derivative pattern (ICLDP). In order to reduce the computational complexity the uniform patterns are applied to both CLDP and ICLDP. Further, uniform CLDP (CLDPu2) and uniform ICLDP (ICLDPu2) are generated respectively. The proposed descriptors are able to exploit individual (R, G and B) spectral channel information and co-relating pair (RG, GB, BR, etc.) of spectral channel information. The retrieval performances of the proposed descriptors (CLDP and ICLDP) are tested by conducting two experiments on Corel-5000 and Corel-10000 benchmark databases. The results after investigation show a significant improvement in terms of precision, average retrieval precision (ARP), recall and average retrieval rate (ARR) as compared to local binary patterns (LBP), local derivative patterns (LDP) and other state-of-the-art techniques for image retrieval.

  1. Integration of Color and Local Derivative Pattern Features for Content-Based Image Indexing and Retrieval

    NASA Astrophysics Data System (ADS)

    Vipparthi, Santosh Kumar; Nagar, Shyam Krishna

    2014-09-01

    This paper presents two new feature descriptors for content based image retrieval (CBIR) application. The proposed two descriptors are named as color local derivative patterns (CLDP) and inter color local derivative pattern (ICLDP). In order to reduce the computational complexity the uniform patterns are applied to both CLDP and ICLDP. Further, uniform CLDP (CLDPu2) and uniform ICLDP (ICLDPu2) are generated respectively. The proposed descriptors are able to exploit individual (R, G and B) spectral channel information and co-relating pair (RG, GB, BR, etc.) of spectral channel information. The retrieval performances of the proposed descriptors (CLDP and ICLDP) are tested by conducting two experiments on Corel-5000 and Corel-10000 benchmark databases. The results after investigation show a significant improvement in terms of precision, average retrieval precision (ARP), recall and average retrieval rate (ARR) as compared to local binary patterns (LBP), local derivative patterns (LDP) and other state-of-the-art techniques for image retrieval.

  2. Wind sets from SMS images - An assessment of quality for GATE. [Synchronous Meteorological Satellite cloud monitoring for GARP Atlantic Tropical Experiment

    NASA Technical Reports Server (NTRS)

    Suchman, D.; Martin, D. W.

    1976-01-01

    The paper analyzes the accuracy, representativeness, and reproducibility of tracer winds in the 1974 GARP Atlantic Tropical Experiment whose data are used as ground truth. The tracer winds were generated by tracking clouds in SMS (Synchronous Meteorological Satellite) images. Data availability limits comparisons to satellite winds with ship winds at the surface and at 250 mb. Attention is focused on how accurately the cloud displacements can be measured and on the extent to which the cloud displacements represent the wind field. Operator errors in obtaining the cloud displacements are examined in a series of reproducibility tests and wind sets. Differences between proximate satellite and ship winds were all under 3 m/sec. Representativeness of cloud tracers for cumulus and cirrus level flow is found to be good within the accuracy of currently available ground truth data.

  3. Wide-Field Near-Infrared Imaging of the L1551 Dark Cloud

    NASA Astrophysics Data System (ADS)

    Hayashi, Masahiko; Pyo, Tae-Soo

    2009-03-01

    We present wide-field near-infrared images of the densest part of the L1551 dark cloud taken with the narrow-band filters for [Fe II] ? 1.644 ?m and H2 v = 1-0 S(1) lines, together with the broadband H and K s filters. Numerous [Fe II] and H2 emission features were detected from the regions around HL/XZ Tau, HH 30, HH 262, L1551 NE, and L1551 IRS 5. Most of the [Fe II] features are compact or jet-like, suggesting that the emission arises from fast shocks occurring in the ejecta of jets. The H2 features are more diffuse and widely distributed in outflow lobes, with none of the H2 features showing the well-collimated emission associated with jets. This implies that the H2 emission originates from slower shocks where the ejecta interacts with ambient material. The outflow structure in the vicinity of the deeply embedded object L1551 NE is revealed, featuring a well-collimated, spatially continuous [Fe II] jet penetrating a fan-shaped infrared reflection nebula. The tangential velocities of knots in the L1551 NE jet are estimated to be 140-190 km s-1 from their proper motions, implying an inclination of 45-60 for the jet axis. A counter-jet from L1551 IRS 5 is detected for the first time in [Fe II]; this probably corresponds to the northern-most of the two jets on the blueshifted side. The relative brightness of the counter-jet suggests a visual extinction of 20-30 mag. The [Fe II] emissions from collimated jets are relatively strong toward L1551 NE and L1551 IRS 5 compared to those toward HL Tau and HH 30. This implies that the jets from the former objects, which are more embedded, have a higher shock velocity and/or a larger gas density than the latter, more revealed objects. The results presented here show that the near-infrared [Fe II] emission is a useful probe of well-collimated jets from deeply embedded sources, in much the same way that optical [S II] emission is used for relatively revealed objects. Based on data collected using the Subaru Telescope, operated by the National Astronomical Observatory of Japan.

  4. A 4.8 AND 8.6 GHz SURVEY OF THE SMALL MAGELLANIC CLOUD: THE IMAGES

    SciTech Connect

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

    2010-11-15

    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 64 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.

  5. [A cloud detection algorithm for MODIS images combining Kmeans clustering and multi-spectral threshold method].

    PubMed

    Wang, Wei; Song, Wei-Guo; Liu, Shi-Xing; Zhang, Yong-Ming; Zheng, Hong-Yang; Tian, Wei

    2011-04-01

    An improved method for detecting cloud combining Kmeans clustering and the multi-spectral threshold approach is described. On the basis of landmark spectrum analysis, MODIS data is categorized into two major types initially by Kmeans method. The first class includes clouds, smoke and snow, and the second class includes vegetation, water and land. Then a multi-spectral threshold detection is applied to eliminate interference such as smoke and snow for the first class. The method is tested with MODIS data at different time under different underlying surface conditions. By visual method to test the performance of the algorithm, it was found that the algorithm can effectively detect smaller area of cloud pixels and exclude the interference of underlying surface, which provides a good foundation for the next fire detection approach. PMID:21714260

  6. A Novel Strategy for Quantum Image Steganography Based on Moiré Pattern

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; Wang, Luo

    2015-03-01

    Image steganography technique is widely used to realize the secrecy transmission. Although its strategies on classical computers have been extensively researched, there are few studies on such strategies on quantum computers. Therefore, in this paper, a novel, secure and keyless steganography approach for images on quantum computers is proposed based on Moiré pattern. Algorithms based on the Moiré pattern are proposed for binary image embedding and extraction. Based on the novel enhanced quantum representation of digital images (NEQR), recursive and progressively layered quantum circuits for embedding and extraction operations are designed. In the end, experiments are done to verify the validity and robustness of proposed methods, which confirms that the approach in this paper is effective in quantum image steganography strategy.

  7. Spatial uncertainty modeling of fuzzy information in images for pattern classification.

    PubMed

    Pham, Tuan D

    2014-01-01

    The modeling of the spatial distribution of image properties is important for many pattern recognition problems in science and engineering. Mathematical methods are needed to quantify the variability of this spatial distribution based on which a decision of classification can be made in an optimal sense. However, image properties are often subject to uncertainty due to both incomplete and imprecise information. This paper presents an integrated approach for estimating the spatial uncertainty of vagueness in images using the theory of geostatistics and the calculus of probability measures of fuzzy events. Such a model for the quantification of spatial uncertainty is utilized as a new image feature extraction method, based on which classifiers can be trained to perform the task of pattern recognition. Applications of the proposed algorithm to the classification of various types of image data suggest the usefulness of the proposed uncertainty modeling technique for texture feature extraction. PMID:25157744

  8. Spatial Uncertainty Modeling of Fuzzy Information in Images for Pattern Classification

    PubMed Central

    Pham, Tuan D.

    2014-01-01

    The modeling of the spatial distribution of image properties is important for many pattern recognition problems in science and engineering. Mathematical methods are needed to quantify the variability of this spatial distribution based on which a decision of classification can be made in an optimal sense. However, image properties are often subject to uncertainty due to both incomplete and imprecise information. This paper presents an integrated approach for estimating the spatial uncertainty of vagueness in images using the theory of geostatistics and the calculus of probability measures of fuzzy events. Such a model for the quantification of spatial uncertainty is utilized as a new image feature extraction method, based on which classifiers can be trained to perform the task of pattern recognition. Applications of the proposed algorithm to the classification of various types of image data suggest the usefulness of the proposed uncertainty modeling technique for texture feature extraction. PMID:25157744

  9. The embedded young stars in the Taurus-Auriga molecular cloud. II - Models for scattered light images

    NASA Technical Reports Server (NTRS)

    Kenyon, Scott J.; Whitney, Barbara A.; Gomez, Mercedes; Hartmann, Lee

    1993-01-01

    We describe NIR imaging observations of embedded young stars in the Taurus-Auriga molecular cloud. We find a large range in J-K and H-K colors for these class I sources. The bluest objects have colors similar to the reddest T Tauri stars in the cloud; redder objects lie slightly above the reddening line for standard ISM dust and have apparent K extinctions of up to 5 mag. Most of these sources also show extended NIR emission on scales of 10-20 arcsec which corresponds to linear sizes of 1500-3000 AU. The NIR colors and nebular morphologies for this sample and the magnitude of linear polarization in several sources suggest scattered light produces most of the NIR emission in these objects. We present modeling results that suggest mass infall rates that agree with predictions for cold clouds and are generally consistent with rates estimated from radiative equilibrium models. For reasonable dust grain parameters, the range of colors and extinctions require flattened density distributions with polar cavities evacuated by bipolar outflows. These results support the idea that infall and outflow occur simultaneously in deeply embedded bipolar outflow sources. The data also indicate fairly large centrifugal radii and large inclinations to the rotational axis for a typical source.

  10. Imaging polychromator for density measurements of polystyrene pellet cloud on the Large Helical Device

    SciTech Connect

    Sharov, I. A. Sergeev, V. Yu.; Miroshnikov, I. V.; Tamura, N.; Sudo, S.; Kuteev, B. V.

    2015-04-15

    Experimental data on spatial distributions of a pellet cloud electron density are necessary for the development of many applications of pellet injection, namely, plasma fuelling, discharge control, and plasma diagnostics. An improved approach of electron density measurements inside the cloud of a polystyrene pellet ablating in hot plasma of the large helical device is described. Density values of (1-30) × 10{sup 16} cm{sup −3} depending on the background plasma parameters and distance from the solid pellet were measured.

  11. Some cloud population statistics

    NASA Technical Reports Server (NTRS)

    Snow, J. William

    1985-01-01

    Photographs of cloud scenes taken from the orbiting space shuttle are being used to assess the overestimation in the amount of cloud cover sensed by satellites at angles other than nadir. Also these photographs and Landsat images indicate that the frequency distributions of clear and of cloudy intervals, at least in simple tropical cloud scenes, may be approximated by common distribution functions.

  12. Measurements of cathode pattern drifts using high-speed imaging in SSPX

    NASA Astrophysics Data System (ADS)

    Romero-Talams, C. A.; Bellan, P. M.

    2004-11-01

    A specially designed high-speed imaging system that can take up to two images for every plasma shot has been installed at the Sustained Spheromak Physics Experiment (SSPX). The imaging system has revealed the existence of bright patterns close to the electrodes during current sustainment and ramp-down. In particular, circular patterns are seen on the end face of the cylindrically shaped cathode. These patterns are azimuthally segmented, approximately concentric with the cathode axis, and appear at discrete radial positions. The anode, in contrast, has patterns near the divertor region that are not as well defined as those at the cathode. The patterns on both electrodes evolve in time. The cathode pattern morphology and position did not vary significantly in less than 0.1 ms. At times greater than 0.1 ms, the cathode patterns elongate toroidally in a constant direction. Reversal of the gun bias magnetic field reversed the elongation direction. This suggests the motion is due to E B drifts near the cathode surface. Possible implications of these drifts on gun current distribution at the cathode surface will be presented.

  13. Temporal pattern of acoustic imaging noise asymmetrically modulates activation in the auditory cortex.

    PubMed

    Ranaweera, Ruwan D; Kwon, Minseok; Hu, Shuowen; Tamer, Gregory G; Luh, Wen-Ming; Talavage, Thomas M

    2016-01-01

    This study investigated the hemisphere-specific effects of the temporal pattern of imaging related acoustic noise on auditory cortex activation. Hemodynamic responses (HDRs) to five temporal patterns of imaging noise corresponding to noise generated by unique combinations of imaging volume and effective repetition time (TR), were obtained using a stroboscopic event-related paradigm with extra-long (≥27.5 s) TR to minimize inter-acquisition effects. In addition to confirmation that fMRI responses in auditory cortex do not behave in a linear manner, temporal patterns of imaging noise were found to modulate both the shape and spatial extent of hemodynamic responses, with classically non-auditory areas exhibiting responses to longer duration noise conditions. Hemispheric analysis revealed the right primary auditory cortex to be more sensitive than the left to the presence of imaging related acoustic noise. Right primary auditory cortex responses were significantly larger during all the conditions. This asymmetry of response to imaging related acoustic noise could lead to different baseline activation levels during acquisition schemes using short TR, inducing an observed asymmetry in the responses to an intended acoustic stimulus through limitations of dynamic range, rather than due to differences in neuronal processing of the stimulus. These results emphasize the importance of accounting for the temporal pattern of the acoustic noise when comparing findings across different fMRI studies, especially those involving acoustic stimulation. PMID:26519093

  14. Computer-aided diagnosis of splenic enlargement using wave pattern of spleen in abdominal CT images

    NASA Astrophysics Data System (ADS)

    Seong, Won; Cho, June-Sik; Noh, Seung-Moo; Park, Jong Won

    2006-03-01

    It is known that the spleen accompanied by liver cirrhosis is hypertrophied or enlarged. We have examined a wave pattern at the left boundary of spleen on the abdominal CT images having liver cirrhosis, and found that they are different from those on the images having a normal liver. It is noticed that the abdominal CT images of patient with liver cirrhosis shows strong bending in the wave pattern. In the case of normal liver, the images may also have a wave pattern, but its bends are not strong. Therefore, the total waving area of the spleen with liver cirrhosis is found to be greater than that of the spleen with a normal liver. Moreover, we found that the waves of the spleen from the image with liver cirrhosis have the higher degree of circularity compared to the normal liver case. Based on the two observations above, we propose an automatic method to diagnose splenic enlargement by using the wave pattern of the spleen in abdominal CT images. The proposed automatic method improves the diagnostic performance compared with the conventional process based on the size of spleen.

  15. Combined Geometric/radiometric Point Cloud Matching for Shear Analysis

    NASA Astrophysics Data System (ADS)

    Gehrke, S.

    2012-07-01

    In the recent past, dense image matching methods such as Semi-Global Matching (SGM) became popular for many applications. The SGM approach has been adapted to and implemented for Leica ADS line-scanner data by North West Geomatics (North West) in co-operation with Leica Geosystems; it is used in North West's production workflow. One of the advantages of ADS imagery is the calibrated color information (RGB and near infrared), extending SGM-derived point clouds to dense "image point clouds" or, more general, information clouds (info clouds). With the goal of automating the quality control of ADS data, info clouds are utilized for Shear Analysis: Three-dimensional offsets of adjacent ADS image strips are determined from a pattern of info cloud pairs in strip overlaps by point cloud matching. The presented approach integrates geometry (height) and radiometry (intensity) information; matching is based on local point-to-plane distances for all points in a given cloud. The offset is derived in a least squares adjustment by applying it to each individual distance computation equation. Using intensities in addition to heights greatly benefits the offset computation, because intensity gradients tend to occur more frequently than height gradients. They can provide or complement the required information for the derivation of planimetric offset components. The paper details the combined geometric/radiometric point cloud matching approach and verifies the results against manual measurements.

  16. Integration of Image Data for Refining Building Boundaries Derived from Point Clouds

    NASA Astrophysics Data System (ADS)

    Perera, S. N.; Hetti Arachchige, N.; Schneider, D.

    2014-08-01

    Geometrically and topologically correct 3D building models are required to satisfy with new demands such as 3D cadastre, map updating, and decision making. More attention on building reconstruction has been paid using Airborne Laser Scanning (ALS) point cloud data. The planimetric accuracy of roof outlines, including step-edges is questionable in building models derived from only point clouds. This paper presents a new approach for the detection of accurate building boundaries by merging point clouds acquired by ALS and aerial photographs. It comprises two major parts: reconstruction of initial roof models from point clouds only, and refinement of their boundaries. A shortest closed circle (graph) analysis method is employed to generate building models in the first step. Having the advantages of high reliability, this method provides reconstruction without prior knowledge of primitive building types even when complex height jumps and various types of building roof are available. The accurate position of boundaries of the initial models is determined by the integration of the edges extracted from aerial photographs. In this process, scene constraints defined based on the initial roof models are introduced as the initial roof models are representing explicit unambiguous geometries about the scene. Experiments were conducted using the ISPRS benchmark test data. Based on test results, we show that the proposed approach can reconstruct 3D building models with higher geometrical (planimetry and vertical) and topological accuracy.

  17. BIOCAT: a pattern recognition platform for customizable biological image classification and annotation

    PubMed Central

    2013-01-01

    Background Pattern recognition algorithms are useful in bioimage informatics applications such as quantifying cellular and subcellular objects, annotating gene expressions, and classifying phenotypes. To provide effective and efficient image classification and annotation for the ever-increasing microscopic images, it is desirable to have tools that can combine and compare various algorithms, and build customizable solution for different biological problems. However, current tools often offer a limited solution in generating user-friendly and extensible tools for annotating higher dimensional images that correspond to multiple complicated categories. Results We develop the BIOimage Classification and Annotation Tool (BIOCAT). It is able to apply pattern recognition algorithms to two- and three-dimensional biological image sets as well as regions of interest (ROIs) in individual images for automatic classification and annotation. We also propose a 3D anisotropic wavelet feature extractor for extracting textural features from 3D images with xy-z resolution disparity. The extractor is one of the about 20 built-in algorithms of feature extractors, selectors and classifiers in BIOCAT. The algorithms are modularized so that they can be chained in a customizable way to form adaptive solution for various problems, and the plugin-based extensibility gives the tool an open architecture to incorporate future algorithms. We have applied BIOCAT to classification and annotation of images and ROIs of different properties with applications in cell biology and neuroscience. Conclusions BIOCAT provides a user-friendly, portable platform for pattern recognition based biological image classification of two- and three- dimensional images and ROIs. We show, via diverse case studies, that different algorithms and their combinations have different suitability for various problems. The customizability of BIOCAT is thus expected to be useful for providing effective and efficient solutions for a variety of biological problems involving image classification and annotation. We also demonstrate the effectiveness of 3D anisotropic wavelet in classifying both 3D image sets and ROIs. PMID:24090164

  18. HOLOGondel: A novel in-situ cloud measurement platform on a cable car with a digital holographic imager

    NASA Astrophysics Data System (ADS)

    Beck, Alexander; Henneberger, Jan; Kanji, Zamin; Lohmann, Ulrike

    2015-04-01

    Cloud particle properties observed in-situ are commonly conducted from airborne or ground-based measurements. When compared to airborne measurements, the advantages of ground-based measurements are a higher spatial resolution and much less costly to perform. However, ground-based observations allow only single-point measurements within a cloud. To overcome this disadvantage, a novel measurement platform with a digital holographic imager has been developed to allow in-situ cloud observations on the roof of a cable car cabin. With a traveling velocity of a cable car of a few m/s, such a measurement platform yields a spatial resolution comparable to those of ground-based measurements. In addition, it is possible to obtain vertical profiles of the microphysical properties within the cloud, because of the vertical distance covered by the cable car of approximately 800m. The major technical challenges for such a measurement platform are the lack of an external power supply and the additional weight constrain on a cable car cabin. To allow continuous operation for eight hours with a battery and to stay within the weight limit of 25kg at the same time, a compact design with carefully chosen material and components with a low power consumption was necessary. The new measurement platform HOLOGondel is equipped with a HOLographic Imager for Microscopic Objects (HOLIMO 3G). Digital in-line holography offers the advantages of measuring simultaneously an ensemble of cloud particles within a well-defined detection volume over a large range of particle size. The image captured, a hologram, yields information about the three-dimensional position, size and a shadow-graph of each particle within the detection volume. The HOLIMO 3G instrument is equipped with a 30MP camera and a 1.8 times magnifying, both-sided telecentric lens system. At a frame rate of six pictures per second a sample volume rate of about 100 cm3s-1 at a maximum resolution of 7 µm is achieved. This configuration allows to measure the vertical profiles of the number concentration and size distribution of liquid cloud droplets and ice crystals, the spatial scale of mixing between these two and the partitioning with respect to particle size. In addition, auxiliary measurements of the temperature, relative humidity and GPS position of the captured images are conducted. A first field campaign will be performed at the Eggishorn in the Bernese Alps from January until March 2015. With its short distance from the research station Jungfraujoch (JFJ) there is a chance to measure the same air masses twice (concurrent measurement with the HOLIMO 3M instrument at JFJ). The comparison of these measurements will contribute to a better understanding of the spatial and temporal evolution of orographic MPCs.

  19. Method for reducing Newton's rings pattern in the scanned image reproduced with film scanners

    NASA Astrophysics Data System (ADS)

    Lu, Ming-feng; Ni, Guo-qiang; Wang, Tao; Zhang, Feng; Tao, Ran; Yuan, Jun

    2013-12-01

    Newton's rings pattern always blurs the scanned image when scanning a film using a film scanner. Such phenomenon is a kind of equal thickness interference, which is caused by the air layer between the film and the glass of the scanner. A lot of methods were proposed to prevent the interference, such as film holder, anti-Newton's rings glass and emulsion direct imaging technology, etc. Those methods are expensive and lack of flexibility. In this paper, Newton's rings pattern is proved to be a 2-D chirp signal. Then, the fractional Fourier transform, which can be understood as the chirp-based decomposition, is introduced to process Newton's rings pattern. A digital filtering method in the fractional Fourier domain is proposed to reduce the Newton's rings pattern. The effectiveness of the proposed method is verified by simulation. Compared with the traditional optical method, the proposed method is more flexible and low cost.

  20. Coupling sky images with three-dimensional radiative transfer models: a new method to estimate cloud optical depth

    NASA Astrophysics Data System (ADS)

    Mejia, F. A.; Kurtz, B.; Murray, K.; Hinkelman, L. M.; Sengupta, M.; Xie, Y.; Kleissl, J.

    2015-10-01

    A method for retrieving cloud optical depth (τc) using a ground-based sky imager (USI) is presented. The Radiance Red-Blue Ratio (RRBR) method is motivated from the analysis of simulated images of various τc produced by a 3-D Radiative Transfer Model (3DRTM). From these images the basic parameters affecting the radiance and RBR of a pixel are identified as the solar zenith angle (θ0), τc, solar pixel angle/scattering angle (ϑs), and pixel zenith angle/view angle (ϑz). The effects of these parameters are described and the functions for radiance, Iλ(τc, θ0, ϑs, ϑz) and the red-blue ratio, RBR(τc, θ0, ϑs, ϑz) are retrieved from the 3DRTM results. RBR, which is commonly used for cloud detection in sky images, provides non-unique solutions for τc, where RBR increases with τc up to about τc = 1 (depending on other parameters) and then decreases. Therefore, the RRBR algorithm uses the measured Iλmeas(ϑs, ϑz), in addition to RBRmeas(ϑs, ϑz) to obtain a unique solution for τc. The RRBR method is applied to images taken by a USI at the Oklahoma Atmospheric Radiation Measurement program (ARM) site over the course of 220 days and validated against measurements from a microwave radiometer (MWR); output from the Min method for overcast skies, and τc retrieved by Beer's law from direct normal irradiance (DNI) measurements. A τc RMSE of 5.6 between the Min method and the USI are observed. The MWR and USI have an RMSE of 2.3 which is well within the uncertainty of the MWR. An RMSE of 0.95 between the USI and DNI retrieved τc is observed. The procedure developed here provides a foundation to test and develop other cloud detection algorithms.

  1. Sensitivity of Satellite-Retrieved Cloud Properties to the Effective Variance of Cloud Droplet Size Distribution

    SciTech Connect

    Arduini, R.F.; Minnis, P.; Smith, W.L.Jr.; Ayers, J.K.; Khaiyer, M.M.; Heck, P.

    2005-03-18

    Cloud reflectance models currently used in cloud property retrievals from satellites have been developed using size distributions defined by a set of fixed effective radii with a fixed effective variance. The satellite retrievals used for the Atmospheric Radiation Measurement (ARM) program assume droplet size distributions with an effective variance value of 0.10 (Minnis et al. 1998); the International Satellite Cloud Climatology Project uses 0.15 (Rossow and Schiffer 1999); and the Moderate Resolution Imaging Spectroradiometer (MODIS) team uses 0.13 (Nakajima and King 1990). These distributions are not necessarily representative of the actual sizes present in the clouds being observed. Because the assumed distributions can affect the reflectance patterns and near-infrared absorption, even for the same droplet effective radius reff, it is desirable to use the optimal size distributions in satellite retrievals of cloud properties. Collocated observations of the same clouds from different geostationary satellites, at different viewing angles, indicate that the current models may not be optimal (Ayers et al. 2005). Similarly, hour-to-hour variations in effective radius and optical depth reveal an unexplained dependence on scattering angle. To explore this issue, this paper examines the sensitivity of the cloud reflectance at 0.65 and 3.90-{micro}m to changes in the effective variance, or the spectral dispersion, of the modeled size distributions. The effects on the scattering phase functions and on the cloud reflectances are presented, as well as some resultant effects on the retrieved cloud properties.

  2. Infrared and Optical Imagings of the Comet 2P/Encke Dust Cloud in the 2003 Return

    NASA Astrophysics Data System (ADS)

    Sarugaku, Yuki; Ishiguro, Masateru; Ueno, Munetaka; Usui, Fumihiko; Reach, William T.

    2015-05-01

    We report contemporaneous imaging observations of the short-period comet 2P/Encke in infrared and optical wavelengths during the 2003 return. Both images show the same unique morphology consisting of a spiky dust cloud near the nucleus and a dust trail extending along the orbit. We conducted a dynamical simulation of dust particles to characterize the morphology and found that dust particles were ejected intensively for a short duration (?10 days) a few days after perihelion passage. The maximum particle size is at least on the order of 1 cm in radius following a differential power-law size distribution with an index of -3.2 to -3.6. The total mass ejected in the 2003 return is at least 1.5 109-1.2 1010 kg, which corresponds to 0.003%-0.03% of the nucleus mass. We derived the albedo of the dust cloud as 0.01-0.04 at a solar phase angle of 26.2, which is consistent with or possibly greater than that of the nucleus. We suppose that impulsive activity such as an outburst is a key to understanding the peculiar appearance of 2P/Encke.

  3. Sahara Dust Cloud

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24

    A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean.

    These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward.

    In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005.

    In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie

    The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the AIRS retrieved total water vapor product as a region of depressed water vapor (brown in the images) migrating slowly Westward toward the Caribbean. The SAL phenomenon inhibits the formation of tropical cyclones and thus has given the West Indies and the East Coast of the US a respite from hurricanes.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  4. Spatial pattern separation of chemicals and frequency-independent components by terahertz spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Watanabe, Yuuki; Kawase, Kodo; Ikari, Tomofumi; Ito, Hiromasa; Ishikawa, Youichi; Minamide, Hiroaki

    2003-10-01

    We separated the component spatial patterns of frequency-dependent absorption in chemicals and frequency-independent components such as plastic, paper, and measurement noise in terahertz (THz) spectroscopic images, using known spectral curves. Our measurement system, which uses a widely tunable coherent THz-wave parametric oscillator source, can image at a specific frequency in the range 1-2 THz. The component patterns of chemicals can easily be extracted by use of the frequency-independent components. This method could be successfully used for nondestructive inspection for the detection of illegal drugs and devices of bioterrorism concealed, e.g., inside mail and packages.

  5. Using aberration test patterns to optimize the performance of EUV aerial imaging microscopes

    SciTech Connect

    Mochi, Iacopo; Goldberg, Kenneth A.; Miyakawa, Ryan; Naulleau, Patrick; Han, Hak-Seung; Huh, Sungmin

    2009-06-16

    The SEMATECH Berkeley Actinic Inspection Tool (AIT) is a prototype EUV-wavelength zoneplate microscope that provides high quality aerial image measurements of EUV reticles. To simplify and improve the alignment procedure we have created and tested arrays of aberration-sensitive patterns on EUV reticles and we have compared their images collected with the AIT to the expected shapes obtained by simulating the theoretical wavefront of the system. We obtained a consistent measure of coma and astigmatism in the center of the field of view using two different patterns, revealing a misalignment condition in the optics.

  6. Speckle pattern of the images of objects exposed to monochromatic coherent terahertz radiation

    SciTech Connect

    Vinokurov, Nikolai A; Knyazev, Boris A; Kulipanov, Gennadii N; Dem'yanenko, M A; Esaev, D G; Chashchina, O I; Cherkasskii, Valerii S

    2009-05-31

    By using a free electron laser and a microbolometer array, real-time images are recorded for the first time in the terahertz range at the rate of up to 90 frames per second. In the case of diffusive illumination of objects by coherent monochromatic radiation, the images consist of speckles. The study of the statistical properties of speckle patterns shows that they are quite accurately described by the theory developed for speckles in the visible range. By averaging a set of images with the help of a rotating scatterer during the exposure time of a frame (20 ms) and by summing statistically independent speckle patterns of many frames, images of the acceptable quality are obtained. The possibilities of terahertz speckle photography and speckle interferometry are discussed. (terahertz radiation)

  7. Investigation of mesoscale cloud features viewed by LANDSAT

    NASA Technical Reports Server (NTRS)

    Sherr, P. E. (Principal Investigator); Feteris, P. J.; Lisa, A. S.; Bowley, C. J.; Fowler, M. G.; Barnes, J. C.

    1976-01-01

    The author has identified the following significant results. Some 50 LANDSAT images displaying mesoscale cloud features were analyzed. This analysis was based on the Rayleigh-Kuettner model describing the formation of that type of mesoscale cloud feature. This model lends itself to computation of the average wind speed in northerly flow from the dimensions of the cloud band configurations measured from a LANDSAT image. In nearly every case, necessary conditions of a curved wind profile and orientation of the cloud streets within 20 degrees of the direction of the mean wind in the convective layer were met. Verification of the results by direct observation was hampered, however, by the incompatibility of the resolution of conventional rawinsonde observations with the scale of the banded cloud patterns measured from LANDSAT data. Comparison seems to be somewhat better in northerly flows than in southerly flows, with the largest discrepancies in wind speed being within 8m/sec, or a factor of two.

  8. Searching for patterns in remote sensing image databases using neural networks

    NASA Technical Reports Server (NTRS)

    Paola, Justin D.; Schowengerdt, Robert A.

    1995-01-01

    We have investigated a method, based on a successful neural network multispectral image classification system, of searching for single patterns in remote sensing databases. While defining the pattern to search for and the feature to be used for that search (spectral, spatial, temporal, etc.) is challenging, a more difficult task is selecting competing patterns to train against the desired pattern. Schemes for competing pattern selection, including random selection and human interpreted selection, are discussed in the context of an example detection of dense urban areas in Landsat Thematic Mapper imagery. When applying the search to multiple images, a simple normalization method can alleviate the problem of inconsistent image calibration. Another potential problem, that of highly compressed data, was found to have a minimal effect on the ability to detect the desired pattern. The neural network algorithm has been implemented using the PVM (Parallel Virtual Machine) library and nearly-optimal speedups have been obtained that help alleviate the long process of searching through imagery.

  9. Imaging surface immobilization chemistry: correlation with cell patterning on non-adhesive hydrogel thin films.

    PubMed

    Takahashi, Hironobu; Emoto, Kazunori; Dubey, Manish; Castner, David G; Grainger, David W

    2008-07-01

    High-fidelity surface functional group (e.g., N-hydroxysuccinimide (NHS) reactive ester) patterning is readily and reliably achieved on commercial poly(ethylene glycol) (PEG)-based polymer films already known to exhibit high performance non-fouling properties in full serum and in cell culture conditions. NHS coupling chemistry co-patterned with methoxy-capped PEG using photolithographic methods is directly spatially imaged using imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) and principal components statistical analysis. Patterned NHS surface reactive zones are clearly resolved at high sensitivity despite the complexity of the polymer matrix chemistry. ToF-SIMS imaging also reveals the presence of photo-resist residue remaining from typical photolithography processing methods. High cross-correlation between various ion-derived ToF-SIMS images is observed, providing sensitive chemical corroboration of pattern chemistry and biological reactivity in complex milieu. Surface-specific protein coupling is observed first by site-selective reaction of streptavidin with NHS patterns, followed by identical patterns of biotinylated Alexa-labeled albumin coupling. This suggests that streptavidin immobilized on the patterns remains bioactive. Fluorescently labeled full serum is shown to react selectively with NHS-reactive regions, with minimal signal from methoxy-capped regions. Insufficient serum is adsorbed under any conditions to these surfaces to support cell attachment in serum-containing media. This reflects the high intrinsic non-adsorptive nature of this chemistry. Fibroblasts attach and proliferate in serum culture only when a cell adhesion peptide (RGD) is first grafted to NHS regions on the PEG-based surfaces. Longer-term serum-based cell culture retains high cell-pattern fidelity that correlates with chemical imaging of both the NHS and RGD patterns and also lack of cell adhesion to methoxy-capped regions. Cell staining shows orientation of adherent cells within the narrow patterned areas. Cell patterns are consistently retained beyond 15 days in serum media. PMID:20700474

  10. Spot Matching of 2-DE Images Using Distance, Intensity, and Pattern Information.

    PubMed

    Xin, Hua-Mei; Zhu, Yuemin

    2016-01-01

    The analysis of a large number of two-dimensional gel electrophoresis (2-DE) images requires developing automatic methods. In such analyses, spot matching plays a fundamental role, in particular for the identification of proteins. We describe a simple and accurate method which allows to automatically and accurately match spots in 2-DE images. The method consists of simultaneously exploiting the distance between the spots, their intensity, and the pattern formed by their spatial configuration. PMID:26611412

  11. Local Wavelet Pattern: A New Feature Descriptor for Image Retrieval in Medical CT Databases.

    PubMed

    Dubey, Shiv Ram; Singh, Satish Kumar; Singh, Rajat Kumar

    2015-12-01

    A new image feature description based on the local wavelet pattern (LWP) is proposed in this paper to characterize the medical computer tomography (CT) images for content-based CT image retrieval. In the proposed work, the LWP is derived for each pixel of the CT image by utilizing the relationship of center pixel with the local neighboring information. In contrast to the local binary pattern that only considers the relationship between a center pixel and its neighboring pixels, the presented approach first utilizes the relationship among the neighboring pixels using local wavelet decomposition, and finally considers its relationship with the center pixel. A center pixel transformation scheme is introduced to match the range of center value with the range of local wavelet decomposed values. Moreover, the introduced local wavelet decomposition scheme is centrally symmetric and suitable for CT images. The novelty of this paper lies in the following two ways: 1) encoding local neighboring information with local wavelet decomposition and 2) computing LWP using local wavelet decomposed values and transformed center pixel values. We tested the performance of our method over three CT image databases in terms of the precision and recall. We also compared the proposed LWP descriptor with the other state-of-the-art local image descriptors, and the experimental results suggest that the proposed method outperforms other methods for CT image retrieval. PMID:26513789

  12. Estimation of color modification in digital images by CFA pattern change.

    PubMed

    Choi, Chang-Hee; Lee, Hae-Yeoun; Lee, Heung-Kyu

    2013-03-10

    Extensive studies have been carried out for detecting image forgery such as copy-move, re-sampling, blurring, and contrast enhancement. Although color modification is a common forgery technique, there is no reported forensic method for detecting this type of manipulation. In this paper, we propose a novel algorithm for estimating color modification in images acquired from digital cameras when the images are modified. Most commercial digital cameras are equipped with a color filter array (CFA) for acquiring the color information of each pixel. As a result, the images acquired from such digital cameras include a trace from the CFA pattern. This pattern is composed of the basic red green blue (RGB) colors, and it is changed when color modification is carried out on the image. We designed an advanced intermediate value counting method for measuring the change in the CFA pattern and estimating the extent of color modification. The proposed method is verified experimentally by using 10,366 test images. The results confirmed the ability of the proposed method to estimate color modification with high accuracy. PMID:23312844

  13. Quantitative analysis and temperature-induced variations of moir pattern in fiber-coupled imaging sensors.

    PubMed

    Karbasi, Salman; Arianpour, Ashkan; Motamedi, Nojan; Mellette, William M; Ford, Joseph E

    2015-06-10

    Imaging fiber bundles can map the curved image surface formed by some high-performance lenses onto flat focal plane detectors. The relative alignment between the focal plane array pixels and the quasi-periodic fiber-bundle cores can impose an undesirable space variant moir pattern, but this effect may be greatly reduced by flat-field calibration, provided that the local responsivity is known. Here we demonstrate a stable metric for spatial analysis of the moir pattern strength, and use it to quantify the effect of relative sensor and fiber-bundle pitch, and that of the Bayer color filter. We measure the thermal dependence of the moir pattern, and the achievable improvement by flat-field calibration at different operating temperatures. We show that a flat-field calibration image at a desired operating temperature can be generated using linear interpolation between white images at several fixed temperatures, comparing the final image quality with an experimentally acquired image at the same temperature. PMID:26192846

  14. Influence of broken cloud fields on reflectance retrievals

    NASA Astrophysics Data System (ADS)

    Sundberg, Robert; Richtsmeier, Steven; Adler-Golden, Steven

    2014-10-01

    Surface solar radiation forecasting permits to predict photovoltaic plant production for a massive and safe integration of solar energy into the electric network. For short-term forecasts (intra-day), methods using images from meteorological geostationary satellites are more suitable than numerical weather prediction models. Forecast schemes consist in assessing cloud motion vectors and in extrapolating cloud patterns from a given satellite image in order to predict cloud cover state above a PV plant. Atmospheric motion vectors retrieval techniques have been studied for several decades in order to improve weather forecasts. However, solar energy forecasting requires the extraction of cloud motion vectors on a finer spatial- and time-resolution than those provided for weather forecast applications. Even if motion vector retrieval is a wide research field in image processing related topics, only block-matching techniques are operationally used for solar energy forecasts via satellite images. In this paper, we propose two motion vectors extraction methods originating from video compression techniques (correlation phase and optical flow methods). We implemented them on a 6-day dataset of Meteosat-10 satellite diurnal images. We proceeded to cloud pattern extrapolation and compared predicted cloud maps against actual ones at different time horizons from 15 minutes to 4 hours ahead. Forecast scores were compared to the state-of-the-art (block matching) method. Correlation phase methods do not outperform block-matching but their computation time is about 25 times shorter. Optical flow based method outperforms all the methods with a satisfactory time computing.

  15. Fabrication and optimization of micro-scale speckle patterns for digital image correlation

    NASA Astrophysics Data System (ADS)

    Zhu, Jianguo; Yan, Gaoshen; He, Guanglong; Chen, Lei

    2016-01-01

    Experimental investigations are performed on the fabrication and optimization of micro-scale speckle patterns formed by spinning an epoxy resin and powder for digital image correlation measurements. New factors influencing the fabrication process, including the ambient temperature, centrifugal velocity, and solidifying time, are carefully analyzed and are evaluated in terms of the average gray gradient and particle agglomeration, and the optimal micro-scale speckle pattern is obtained with the proposed parameters in the fabrication process. Additionally, the micro-scale speckle pattern is experimentally verified by performing prescribed rigid-body translation tests, and the relative errors are approximately 1.5%. Finally, the micro-scale speckle patterns are transferred to tensile specimens of aluminum and a polymer material with a V notch. The measurement results are consistent with the theoretical predictions, and this agreement demonstrates the feasibility and accuracy of the micro-scale speckle patterns.

  16. Remote sensing of cloud, aerosol, and water vapor properties from the moderate resolution imaging spectrometer (MODIS)

    NASA Technical Reports Server (NTRS)

    King, Michael D.; Kaufman, Yoram J.; Menzel, W. Paul; Tanre, Didier D.

    1992-01-01

    The authors describe the status of MODIS-N and its companion instrument MODIS-T (tilt), a tiltable cross-track scanning spectrometer with 32 uniformly spaced channels between 0.410 and 0.875 micron. They review the various methods being developed for the remote sensing of atmospheric properties using MODIS, placing primary emphasis on the principal atmospheric applications of determining the optical, microphysical, and physical properties of clouds and aerosol particles from spectral reflection and thermal emission measurements. In addition to cloud and aerosol properties, MODIS-N will be used for determining the total precipitable water vapor and atmospheric stability. The physical principles behind the determination of each of these atmospheric products are described, together with an example of their application to aircraft and/or satellite measurements.

  17. Cloud Information

    Atmospheric Science Data Center

    2014-09-25

    Daylight cloud amount (percent) Percent of cloud amount during daylight within a region. Cloud amount at ... Percent of cloud amount within a region. Frequency of cloud amount at 3-hourly intervals (percent) Percent of ...

  18. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  19. Spatiotemporal Mining of Time-Series Remote Sensing Images Based on Sequential Pattern Mining

    NASA Astrophysics Data System (ADS)

    Liu, H. C.; He, G. J.; Zhang, X. M.; Jiang, W.; Ling, S. G.

    2015-07-01

    With the continuous development of satellite techniques, it is now possible to acquire a regular series of images concerning a given geographical zone with both high accuracy and low cost. Research on how best to effectively process huge volumes of observational data obtained on different dates for a specific geographical zone, and to exploit the valuable information regarding land cover contained in these images has received increasing interest from the remote sensing community. In contrast to traditional land cover change measures using pair-wise comparisons that emphasize the compositional or configurational changes between dates, this research focuses on the analysis of the temporal sequence of land cover dynamics, which refers to the succession of land cover types for a given area over more than two observational periods. Using a time series of classified Landsat images, ranging from 2006 to 2011, a sequential pattern mining method was extended to this spatiotemporal context to extract sets of connected pixels sharing similar temporal evolutions. The resultant sequential patterns could be selected (or not) based on the range of support values. These selected patterns were used to explore the spatial compositions and temporal evolutions of land cover change within the study region. Experimental results showed that continuous patterns that represent consistent land cover over time appeared as quite homogeneous zones, which agreed with our domain knowledge. Discontinuous patterns that represent land cover change trajectories were dominated by the transition from vegetation to bare land, especially during 2009-2010. This approach quantified land cover changes in terms of the percentage area affected and mapped the spatial distribution of these changes. Sequential pattern mining has been used for string mining or itemset mining in transactions analysis. The expected novel significance of this study is the generalization of the application of the sequential pattern mining method for capturing the spatial variability of landscape patterns, and their trajectories of change, to reveal information regarding process regularities with satellite imagery.

  20. A practical approach to optimizing the preparation of speckle patterns for digital-image correlation

    NASA Astrophysics Data System (ADS)

    Lionello, Giacomo; Cristofolini, Luca

    2014-10-01

    The quality of strain measurements by digital image correlation (DIC) strongly depends on the quality of the pattern on the specimen’s surface. An ideal pattern should be highly contrasted, stochastic, and isotropic. In addition, the speckle pattern should have an average size that exceeds the image pixel size by a factor of 3-5. (Smaller speckles cause poor contrast, and larger speckles cause poor spatial resolution.) Finally, the ideal pattern should have a limited scatter in terms of speckle sizes. The aims of this study were: (i) to define the ideal speckle size in relation to the specimen size and acquisition system; (ii) provide practical guidelines to identify the optimal settings of an airbrush gun, in order to produce a pattern that is as close as possible to the desired one while minimizing the scatter of speckle sizes. Patterns of different sizes were produced using two different airbrush guns with different settings of the four most influential factors (dilution, airflow setting, spraying distance, and air pressure). A full-factorial DOE strategy was implemented to explore the four factors at two levels each: 36 specimens were analyzed for each of the 16 combinations. The images were acquired using the digital cameras of a DIC system. The distribution of speckle sizes was analyzed to calculate the average speckle size and the standard deviation of the corresponding truncated Gaussian distribution. A mathematical model was built to enable prediction of the average speckle size in relation to the airbrush gun settings. We showed that it is possible to obtain a pattern with a highly controlled average and a limited scatter of speckle sizes, so as to match the ideal distribution of speckle sizes for DIC. Although the settings identified here apply only to the specific equipment being used, this method can be adapted to any airbrush to produce a desired speckle pattern.

  1. Passive multiangle imaging of clouds, aerosols, and atmospheric dynamics: Broadening our vision from MISR to WindCam and MSPI

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Wu, D. L.; Chipman, R.; Davis, A.; Misr Science Team

    2010-12-01

    The Multi-angle Imaging SpectroRadiometer (MISR) has been collecting global Earth data from NASAs Terra satellite since February 2000. With its nine along-track view angles, four visible/near-infrared spectral bands, intrinsic spatial resolution of 275 m, and stable calibration, no instrument that combines MISRs attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. The MISR data record provides unprecedented opportunities for characterizing long-term variability in aerosol and cloud structure and atmospheric dynamics, including measurements of the vertical distributions of clouds; aerosol (smoke, volcanic, and dust) plume heights and global optical depths and particle properties; and pole-to-pole height-resolved winds. To extend what has been learned during the first decade of MISR observations, we are developing the WindCam and Multiangle SpectroPolarimetric Imager (MSPI) instruments. WindCam will enable MISR-like stereo observations over a broader swath using a much more compact sensor design. MSPI expands MISR capabilities through broader spectral coverage (ultraviolet to shortwave infrared), wider swath (enabling more rapid global coverage), and incorporation of high-accuracy polarimetric imaging, which will provide greater sensitivity to particle microphysics. A ground-based prototype camera (GroundMSPI) with spectral coverage from 355-935 nm has been built and an airborne version (AirMSPI) is ready for flight on NASAs ER-2 high-altitude aircraft. Algorithm developments and improvements enabled by increases in computational speed since Terra launch are being explored with MISR data, and will be needed to handle the rich information content of these MISR successor instruments.

  2. Photoacoustic image patterns of breast carcinoma and comparisons with Magnetic Resonance Imaging and vascular stained histopathology

    NASA Astrophysics Data System (ADS)

    Heijblom, M.; Piras, D.; Brinkhuis, M.; van Hespen, J. C. G.; van den Engh, F. M.; van der Schaaf, M.; Klaase, J. M.; van Leeuwen, T. G.; Steenbergen, W.; Manohar, S.

    2015-07-01

    Photoacoustic (optoacoustic) imaging can visualize vasculature deep in tissue using the high contrast of hemoglobin to light, with the high-resolution possible with ultrasound detection. Since angiogenesis, one of the hallmarks of cancer, leads to increased vascularity, photoacoustics holds promise in imaging breast cancer as shown in proof-of-principle studies. Here for the first time, we investigate if there are specific photoacoustic appearances of breast malignancies which can be related to the tumor vascularity, using an upgraded research imaging system, the Twente Photoacoustic Mammoscope. In addition to comparisons with x-ray and ultrasound images, in subsets of cases the photoacoustic images were compared with MR images, and with vascular staining in histopathology. We were able to identify lesions in suspect breasts at the expected locations in 28 of 29 cases. We discovered generally three types of photoacoustic appearances reminiscent of contrast enhancement types reported in MR imaging of breast malignancies, and first insights were gained into the relationship with tumor vascularity.

  3. Photoacoustic image patterns of breast carcinoma and comparisons with Magnetic Resonance Imaging and vascular stained histopathology

    PubMed Central

    Heijblom, M.; Piras, D.; Brinkhuis, M.; van Hespen, J. C. G.; van den Engh, F. M.; van der Schaaf, M.; Klaase, J. M.; van Leeuwen, T. G.; Steenbergen, W.; Manohar, S.

    2015-01-01

    Photoacoustic (optoacoustic) imaging can visualize vasculature deep in tissue using the high contrast of hemoglobin to light, with the high-resolution possible with ultrasound detection. Since angiogenesis, one of the hallmarks of cancer, leads to increased vascularity, photoacoustics holds promise in imaging breast cancer as shown in proof-of-principle studies. Here for the first time, we investigate if there are specific photoacoustic appearances of breast malignancies which can be related to the tumor vascularity, using an upgraded research imaging system, the Twente Photoacoustic Mammoscope. In addition to comparisons with x-ray and ultrasound images, in subsets of cases the photoacoustic images were compared with MR images, and with vascular staining in histopathology. We were able to identify lesions in suspect breasts at the expected locations in 28 of 29 cases. We discovered generally three types of photoacoustic appearances reminiscent of contrast enhancement types reported in MR imaging of breast malignancies, and first insights were gained into the relationship with tumor vascularity. PMID:26159440

  4. Two-phase flow patterns characteristics analysis based on image and conductance sensors

    NASA Astrophysics Data System (ADS)

    Wang, Zhenya; Jin, Ningde; Wang, Chun; Wang, Jinxiang

    2008-10-01

    In order to study the temporal and spatial evolution characteristics of gas-liquid two-phase flow pattern, the two-phase flow monitoring system composed of high-speed dynamic camera and Vertical Multi-Electrode Array conductance sensor (VMEA) was utilized to shoot dynamic images and acquire the conductance fluctuating signals of 5 typical vertical gas-liquid two-phase flow patterns in a 125mm i.d. upward pipe. Gray level co-occurrence matrix (GLCM) was used to extract four time-varying characteristic parameter indices which represented different flow image texture structures and also Lempel-Ziv complexity of them were calculated. Then the transition of flow structure and flow property were comprehensively analyzed, combining the result derived from image information with recurrence plots (RPs) and Lempel-Ziv complexity of conductance fluctuating signals. The study showed that the line texture structure of RPs enabled to indicate flow pattern characteristics; the flow image texture structure characteristic parameters sequence described the variance of flow structure and dynamical complexity of different flow patterns.

  5. Toward Image-Based Three-Dimensional Reconstruction from Cubesats: Impacts of Spatial Resolution and SNR on Point Cloud Quality

    NASA Astrophysics Data System (ADS)

    Stoddard, Jordyn

    The adoption of cube-satellites (cubesats) by the space community has drastically lowered the cost of access to space and reduced the development lifecycle from the hundreds of millions of dollars spent on traditional decade-long programs. Rapid deployment and low cost are attractive features of cubesat-based imaging that are conducive to applications such as disaster response and monitoring. One proposed application is 3D surface modeling through a high revisit rate constellation of cubesat imagers. This work begins with the characterization of an existing design for a cubesat imager based on ground sampled distance (GSD), signal-to-noise ratio (SNR), and smear. From this characterization, an existing 3D workflow is applied to datasets that have been degraded within the regime of spatial resolutions and signal-to-noise ratios anticipated for the cubesat imager. The fidelity of resulting point clouds are assessed locally for both an urban and a natural scene. The height of a building and normals to its surfaces are calculated from the urban scene, while quarry depth estimates and rough volume estimates of a pile of rocks are produced from the natural scene. Though the reconstructed scene geometry and completeness of the scene suffer noticeably from the degraded imagery, results indicate that useful information can still be extracted using some of these techniques up to a simulated GSD of 2 meters.

  6. Saharan Dust Cloud

    Atmospheric Science Data Center

    2013-04-16

    article title:  Saharan Dust Cloud Blows Westward     Full Image A huge dust cloud blown westward from the Algerian desert is now wafting over the ... dramatic sunsets and possibly a light coating of red-brown dust on vehicles from Florida to Texas. This image, captured by JPL's ...

  7. On the parameterization of patterns in the imaging atmospheric Cherenkov technique

    NASA Astrophysics Data System (ADS)

    Akhperjanian, A.; Sahakian, V.

    1999-11-01

    A new method for analytical description of images (patterns) of the air showers detected by imaging atmospheric Cherenkov telescopes is proposed. It is shown that the generally accepted procedure constructs the image as a fourth-order plane curve (Booth's lemniscate). The method proposed for.m.s. a uniformly illuminated elliptical image preserving the same first- and second-order moments of the registered light disribution. Such a representation describes the angular size of image correctly and allows us to conclude that pixel size less than 0.2 is not particularly advantageous. Unified formulae for the calculation of Hillas' as well as the new parameters are presented. A comparative analysis of the approaches for separation of gamma- and proton-induced air showers is made. A new parameter is proposed which is more effective than AZWIDTH.

  8. Bioacoustic systems: insights for acoustical imaging and pattern recognition (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Altes, Richard A.

    1987-09-01

    Standard performance measures and statistical tests must be altered for research on animal sonar. The narrowband range-Doppler ambiguity function must be redefined to analyze wideband signals. A new range, cross-range ambiguity function is needed to represent angle estimation and spatial resolution properties of animal sonar systems. Echoes are transformed into time-frequency (spectrogram-like) representations by the peripheral auditory system. Detection, estimation, and pattern recognition capabilities of animals should thus be analyzed in terms of operations on spectrograms. The methods developed for bioacoustic research yield new insights into the design of man-made imaging and pattern recognition systems. The range, cross-range ambiguity function can be used to improve imaging performance. Important features for echo pattern recognition are illustrated by time-frequency plots showing (i) principal components for spectrograms and (ii) templates for optimum discrimination between data classes.

  9. Teaching image processing and pattern recognition with the Intel OpenCV library

    NASA Astrophysics Data System (ADS)

    Kozłowski, Adam; Królak, Aleksandra

    2009-06-01

    In this paper we present an approach to teaching image processing and pattern recognition with the use of the OpenCV library. Image processing, pattern recognition and computer vision are important branches of science and apply to tasks ranging from critical, involving medical diagnostics, to everyday tasks including art and entertainment purposes. It is therefore crucial to provide students of image processing and pattern recognition with the most up-to-date solutions available. In the Institute of Electronics at the Technical University of Lodz we facilitate the teaching process in this subject with the OpenCV library, which is an open-source set of classes, functions and procedures that can be used in programming efficient and innovative algorithms for various purposes. The topics of student projects completed with the help of the OpenCV library range from automatic correction of image quality parameters or creation of panoramic images from video to pedestrian tracking in surveillance camera video sequences or head-movement-based mouse cursor control for the motorically impaired.

  10. Effect of Clouds on Optical Imaging of the Space Shuttle During the Ascent Phase: A Statistical Analysis Based on a 3D Model

    NASA Technical Reports Server (NTRS)

    Short, David A.; Lane, Robert E., Jr.; Winters, Katherine A.; Madura, John T.

    2004-01-01

    Clouds are highly effective in obscuring optical images of the Space Shuttle taken during its ascent by ground-based and airborne tracking cameras. Because the imagery is used for quick-look and post-flight engineering analysis, the Columbia Accident Investigation Board (CAIB) recommended the return-to-flight effort include an upgrade of the imaging system to enable it to obtain at least three useful views of the Shuttle from lift-off to at least solid rocket booster (SRB) separation (NASA 2003). The lifetimes of individual cloud elements capable of obscuring optical views of the Shuttle are typically 20 minutes or less. Therefore, accurately observing and forecasting cloud obscuration over an extended network of cameras poses an unprecedented challenge for the current state of observational and modeling techniques. In addition, even the best numerical simulations based on real observations will never reach "truth." In order to quantify the risk that clouds would obscure optical imagery of the Shuttle, a 3D model to calculate probabilistic risk was developed. The model was used to estimate the ability of a network of optical imaging cameras to obtain at least N simultaneous views of the Shuttle from lift-off to SRB separation in the presence of an idealized, randomized cloud field.

  11. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

    NASA Astrophysics Data System (ADS)

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-02-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment.

  12. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography.

    PubMed

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-01-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment. PMID:26902520

  13. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

    PubMed Central

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-01-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment. PMID:26902520

  14. Differences of eye movement pattern in natural and man-made scenes and image categorization with the help of these patterns.

    PubMed

    Momtaz, Hassan Zanganeh; Daliri, Mohammad Reza

    2016-03-01

    In this paper, we investigated the parameters related to eye movement patterns of individuals while viewing images that consist of natural and man-made scenes. These parameters are as follows: number of fixations and saccades, fixation duration, saccade amplitude and distribution of fixation locations. We explored the way in which individuals look at images of different semantic categories, and used this information for automatic image classification. We showed that the eye movements and the contents of eye fixation locations of observers differ for images of different semantic categories. These differences were used effectively in automatic image categorization. Another goal of this study was to find the answer of this question that "whether the image patches of fixation points have sufficient information for image categorization?" To achieve this goal, a number of patches with different sizes from two different image categories was extracted. These patches, which were selected at the location of eye fixation points, were used to form a feature vector based on K-means clustering algorithm. Then, different statistical classifiers were trained for categorization purpose. The results showed that it is possible to predict the image category by using the feature vectors derived from the image patches. We found significant differences in parameters of eye movement pattern between the two image categories (average across subjects). We could categorize images by using these parameters as features. The results also showed that it is possible to predict the image category by using image patches around the subjects' fixation points. PMID:26443008

  15. Abnormal Image Detection in Endoscopy Videos Using a Filter Bank and Local Binary Patterns

    PubMed Central

    Nawarathna, Ruwan; Oh, JungHwan; Muthukudage, Jayantha; Tavanapong, Wallapak; Wong, Johnny; de Groen, Piet C.; Tang, Shou Jiang

    2014-01-01

    Finding mucosal abnormalities (e.g., erythema, blood, ulcer, erosion, and polyp) is one of the most essential tasks during endoscopy video review. Since these abnormalities typically appear in a small number of frames (around 5% of the total frame number), automated detection of frames with an abnormality can save physicians time significantly. In this paper, we propose a new multi-texture analysis method that effectively discerns images showing mucosal abnormalities from the ones without any abnormality since most abnormalities in endoscopy images have textures that are clearly distinguishable from normal textures using an advanced image texture analysis method. The method uses a texton histogram of an image block as features. The histogram captures the distribution of different textons representing various textures in an endoscopy image. The textons are representative response vectors of an application of a combination of Leung and Malik (LM) filter bank (i.e., a set of image filters) and a set of Local Binary Patterns on the image. Our experimental results indicate that the proposed method achieves 92% recall and 91.8% specificity on wireless capsule endoscopy (WCE) images and 91% recall and 90.8% specificity on colonoscopy images. PMID:25132723

  16. Abnormal Image Detection in Endoscopy Videos Using a Filter Bank and Local Binary Patterns.

    PubMed

    Nawarathna, Ruwan; Oh, JungHwan; Muthukudage, Jayantha; Tavanapong, Wallapak; Wong, Johnny; de Groen, Piet C; Tang, Shou Jiang

    2014-11-20

    Finding mucosal abnormalities (e.g., erythema, blood, ulcer, erosion, and polyp) is one of the most essential tasks during endoscopy video review. Since these abnormalities typically appear in a small number of frames (around 5% of the total frame number), automated detection of frames with an abnormality can save physician's time significantly. In this paper, we propose a new multi-texture analysis method that effectively discerns images showing mucosal abnormalities from the ones without any abnormality since most abnormalities in endoscopy images have textures that are clearly distinguishable from normal textures using an advanced image texture analysis method. The method uses a "texton histogram" of an image block as features. The histogram captures the distribution of different "textons" representing various textures in an endoscopy image. The textons are representative response vectors of an application of a combination of Leung and Malik (LM) filter bank (i.e., a set of image filters) and a set of Local Binary Patterns on the image. Our experimental results indicate that the proposed method achieves 92% recall and 91.8% specificity on wireless capsule endoscopy (WCE) images and 91% recall and 90.8% specificity on colonoscopy images. PMID:25132723

  17. Requirements and Implementation Feasibility for a CubeSat Thermal Infrared Imaging System to Monitor the Structure of Volcanic Ash Clouds

    NASA Astrophysics Data System (ADS)

    Thorsen, D.; Carroll, R.; Webley, P.; Hawkins, J.

    2014-12-01

    The 2010 eruption of the Eyjafjallajkull volcano in Iceland caused the cancellation of approximately 108,000 flights over an 8-day period, disrupted air traffic worldwide, and cost the airline industry more than $400 million per day. The inconvenience and economic impact of this and similar events, such as Puyehue-Cordon-Caulle in 2011, have heightened the interest in developing improved satellite remote sensing techniques for monitoring volcanic plumes and drifting clouds. For aviation safety, the operational/research community has started to move towards classifying the concentrations within volcanic plumes and clouds. Additionally, volcanic ash transport and dispersion (VATD) models are often used for forecasting ash cloud locations and they require knowledge of the structure of the erupting column to improve their ash simulations and also downwind 3-D maps of the ash cloud to calibrate/validate their modeling output. Existing remote sensing satellites utilize a brightness temperature method with thermal infrared (TIR) measurements from 10 - 12 ?m to determine mass loading of volcanic ash along a single line of sight, but they have infrequent revisit times and they cannot resolve the three-dimensional structure of the ash clouds. A cluster of CubeSats dedicated to the monitoring of volcanic ash and plumes could provide both more frequent updates and the multi-aspect images needed to resolve the density structure of volcanic ash clouds and plumes. In this presentation, we discuss the feasibility and requirements for a CubeSat TIR imaging system and the associated on-board image processing that would be required to monitor the structure of volcanic ash clouds from Low Earth Orbit.

  18. Voyager 1 imaging and IRIS observations of Jovian methane absorption and thermal emission: Implications for cloud structure

    NASA Technical Reports Server (NTRS)

    West, R. A.; Kupferman, P. N.; Hart, H.

    1984-01-01

    Images from three filters of the Voyager 1 wide angle camera are used to measure the continuum reflectivity and spectral gradient near 6000 A and the 6190 A band methane/continuum ratio for a variety of cloud features in Jupiter's atmosphere. The dark barge features in the North Equatorial Belt have anomalously strong positive continuum spectral gradients suggesting unique composition. Methane absorption is shown at unprecedented spatial scales for the Great Red Spot and its immediate environment, for a dark barge feature in the North Equatorial Belt, and for two hot spot and plume regions in the North Equatorial Belt. Methane absorption and five micrometer emission are correlated in the vicinity of the Great Red Spot but are anticorrelated in one of the plume hot spot regions. Methane absorption and simultaneous maps of five micrometer brightness temperature is quantitatively compared to realistic cloud structure models which include multiple scattering at five micrometer as well as in the visible. Variability in H2 quadrupole lines are also investigated.

  19. Cloud Arcs in the Western Pacific

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Small cumulus clouds in this natural-color view from the Multi-angle Imaging SpectroRadiometer have formed a distinctive series of quasi-circular arcs. Clues regarding the formation of these arcs can be found by noting that larger clouds exist in the interior of each arc.

    The interior clouds are thicker and likely to be more convectively active than the other clouds, causing much of the air near the centers of the arcs to rise. This air spreads out horizontally in all directions as it rises and continues to spread out as it begins to sink back to the surface. This pushes any existing small cumulus clouds away from the central region of convection.

    As the air sinks, it also warms, preventing other small clouds from forming, so that the regions just inside the arcs are kept clear. At the arcs, the horizontal flow of sinking air is now quite weak and on meeting the undisturbed air it can rise again slightly -- possibly assisting in the formation of new small cumulus clouds. Although examples of the continuity of air, in which every rising air motion must be compensated by a sinking motion elsewhere, are very common, the degree of organization exhibited here is relatively rare, as the wind field at different altitudes usually disrupts such patterns. The degree of self organization of this cloud image, whereby three or four such circular events form a quasi-periodic pattern, probably also requires a relatively uncommon combination of wind, temperature and humidity conditions for it to occur.

    The image was acquired by MISR's nadir camera on March 11, 2002, and is centered west of the Marshall Islands. Enewetak Atoll is discernible through thin cloud as the turquoise band near the right-hand edge of the image.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and views almost the entire globe every 9 days. This image is a portion of the data acquired during Terra orbit 11863, and covers an area of about 380 kilometers x 345 kilometers. It utilizes data from blocks 80 to 82 within World Reference System-2 path 90.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  20. Comparison of point clouds derived from aerial image matching with data from airborne laser scanning. (Polish Title: Porwnanie wa?ciwo?ci chmury punktw wygenerowanej metod? dopasowania obrazw zdj?? lotniczych z danymi z lotniczego skanowania)

    NASA Astrophysics Data System (ADS)

    Dominik, W.

    2014-12-01

    The aim of this study was to investigate the properties of point clouds derived from aerial image matching and to compare them with point clouds from airborne laser scanning. A set of aerial images acquired in years 2010-2013 over the city of Elblag were used for the analysis. Images were acquired with the use of three digital cameras: DMC II 230, DMC I and DigiCAM60 with a GSD varying from 4.5 cm to 15 cm. Eight sets of images that were used in the study were acquired at different stages of the growing season - from March to December. Two LiDAR point clouds were used for the comparison - one with a density of 1.3 p/m2 and a second with a density of 10 p/m2. Based on the input images point clouds were created with the use of the semi-global matching method. The properties of the obtained point clouds were analyzed in three ways: - by the comparison of the vertical accuracy of point clouds with reference to a terrain profile surveyed on bare ground with GPS-RTK method - by visual assessment of point cloud profiles generated both from SGM and LiDAR point clouds - by visual assessment of a digital surface model generated from a SGM point cloud with reference to a digital surface model generated from a LiDAR point cloud. The conducted studies allowed a number of observations about the quality of SGM point clouds to be formulated with respect to different factors. The main factors having influence on the quality of SGM point clouds are GSD and base/height ratio. The essential problem related to SGM point clouds are areas covered with vegetation where SGM point clouds are visibly worse in terms of both accuracy and the representation of terrain surface. It is difficult to expect that in these areas SGM point clouds could replace LiDAR point clouds. This leads to a general conclusion that SGM point clouds are less reliable, more unpredictable and are dependent on more factors than LiDAR point clouds. Nevertheless, SGM point clouds generated with appropriate parameters can have better accuracy than LiDAR point clouds and present more detailed information about the terrain surface.

  1. Spatial and Temporal Distribution of Clouds Observed by MODIS Onboard the Terra and Aqua Satellites

    NASA Technical Reports Server (NTRS)

    King, Michael D.; Platnick, Steven; Menzel, W. Paul; Ackerman, Steven A.; Hubanks, Paul A.

    2012-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) was developed by NASA and launched aboard the Terra spacecraft on December 18, 1999 and Aqua spacecraft on May 4, 2002. A comprehensive set of remote sensing algorithms for the retrieval of cloud physical and optical properties have enabled over twelve years of continuous observations of cloud properties from Terra and over nine years from Aqua. The archived products from these algorithms include 1 km pixel-level (Level-2) and global gridded Level-3 products. In addition to an extensive cloud mask, products include cloud-top properties (temperature, pressure, effective emissivity), cloud thermodynamic phase, cloud optical and microphysical parameters (optical thickness, effective particle radius, water path), as well as derived statistics. Results include the latitudinal distribution of cloud optical and radiative properties for both liquid water and ice clouds, as well as latitudinal distributions of cloud top pressure and cloud top temperature. MODIS finds the cloud fraction, as derived by the cloud mask, is nearly identical during the day and night, with only modest diurnal variation. Globally, the cloud fraction derived by the MODIS cloud mask is approx.67%, with somewhat more clouds over land during the afternoon and less clouds over ocean in the afternoon, with very little difference in global cloud cover between Terra and Aqua. Overall, cloud fraction over land is approx.55%, with a distinctive seasonal cycle, whereas the ocean cloudiness is much higher, around 72%, with much reduced seasonal variation. Cloud top pressure and temperature have distinct spatial and temporal patterns, and clearly reflect our understanding of the global cloud distribution. High clouds are especially prevalent over the northern hemisphere continents between 30 and 50 . Aqua and Terra have comparable zonal cloud top pressures, with Aqua having somewhat higher clouds (cloud top pressures lower by 100 hPa) over land due to afternoon deep convection. The coldest cloud tops (colder than 230 K) generally occur over Antarctica and the high clouds in the tropics (ITCZ and the deep convective clouds over the western tropical Pacific and Indian sub-continent).

  2. An Approach to Improve the Quality of Infrared Images of Vein-Patterns

    PubMed Central

    Lin, Chih-Lung

    2011-01-01

    This study develops an approach to improve the quality of infrared (IR) images of vein-patterns, which usually have noise, low contrast, low brightness and small objects of interest, thus requiring preprocessing to improve their quality. The main characteristics of the proposed approach are that no prior knowledge about the IR image is necessary and no parameters must be preset. Two main goals are sought: impulse noise reduction and adaptive contrast enhancement technologies. In our study, a fast median-based filter (FMBF) is developed as a noise reduction method. It is based on an IR imaging mechanism to detect the noisy pixels and on a modified median-based filter to remove the noisy pixels in IR images. FMBF has the advantage of a low computation load. In addition, FMBF can retain reasonably good edges and texture information when the size of the filter window increases. The most important advantage is that the peak signal-to-noise ratio (PSNR) caused by FMBF is higher than the PSNR caused by the median filter. A hybrid cumulative histogram equalization (HCHE) is proposed for adaptive contrast enhancement. HCHE can automatically generate a hybrid cumulative histogram (HCH) based on two different pieces of information about the image histogram. HCHE can improve the enhancement effect on hot objects rather than background. The experimental results are addressed and demonstrate that the proposed approach is feasible for use as an effective and adaptive process for enhancing the quality of IR vein-pattern images. PMID:22247674

  3. Decomposition of brain diffusion imaging data uncovers latent schizophrenias with distinct patterns of white matter anisotropy.

    PubMed

    Arnedo, Javier; Mamah, Daniel; Baranger, David A; Harms, Michael P; Barch, Deanna M; Svrakic, Dragan M; de Erausquin, Gabriel A; Cloninger, C Robert; Zwir, Igor

    2015-10-15

    Fractional anisotropy (FA) analysis of diffusion tensor-images (DTI) has yielded inconsistent abnormalities in schizophrenia (SZ). Inconsistencies may arise from averaging heterogeneous groups of patients. Here we investigate whether SZ is a heterogeneous group of disorders distinguished by distinct patterns of FA reductions. We developed a Generalized Factorization Method (GFM) to identify biclusters (i.e., subsets of subjects associated with a subset of particular characteristics, such as low FA in specific regions). GFM appropriately assembles a collection of unsupervised techniques with Non-negative Matrix Factorization to generate biclusters, rather than averaging across all subjects and all their characteristics. DTI tract-based spatial statistics images, which output is the locally maximal FA projected onto the group white matter skeleton, were analyzed in 47 SZ and 36 healthy subjects, identifying 8 biclusters. The mean FA of the voxels of each bicluster was significantly different from those of other SZ subjects or 36 healthy controls. The eight biclusters were organized into four more general patterns of low FA in specific regions: 1) genu of corpus callosum (GCC), 2) fornix (FX)+external capsule (EC), 3) splenium of CC (SCC)+retrolenticular limb (RLIC)+posterior limb (PLIC) of the internal capsule, and 4) anterior limb of the internal capsule. These patterns were significantly associated with particular clinical features: Pattern 1 (GCC) with bizarre behavior, pattern 2 (FX+EC) with prominent delusions, and pattern 3 (SCC+RLIC+PLIC) with negative symptoms including disorganized speech. The uncovered patterns suggest that SZ is a heterogeneous group of disorders that can be distinguished by different patterns of FA reductions associated with distinct clinical features. PMID:26151103

  4. Local tetra patterns: a new feature descriptor for content-based image retrieval.

    PubMed

    Murala, Subrahmanyam; Maheshwari, R P; Balasubramanian, R

    2012-05-01

    In this paper, we propose a novel image indexing and retrieval algorithm using local tetra patterns (LTrPs) for content-based image retrieval (CBIR). The standard local binary pattern (LBP) and local ternary pattern (LTP) encode the relationship between the referenced pixel and its surrounding neighbors by computing gray-level difference. The proposed method encodes the relationship between the referenced pixel and its neighbors, based on the directions that are calculated using the first-order derivatives in vertical and horizontal directions. In addition, we propose a generic strategy to compute nth-order LTrP using (n - 1)th-order horizontal and vertical derivatives for efficient CBIR and analyze the effectiveness of our proposed algorithm by combining it with the Gabor transform. The performance of the proposed method is compared with the LBP, the local derivative patterns, and the LTP based on the results obtained using benchmark image databases viz., Corel 1000 database (DB1), Brodatz texture database (DB2), and MIT VisTex database (DB3). Performance analysis shows that the proposed method improves the retrieval result from 70.34%/44.9% to 75.9%/48.7% in terms of average precision/average recall on database DB1, and from 79.97% to 85.30% and 82.23% to 90.02% in terms of average retrieval rate on databases DB2 and DB3, respectively, as compared with the standard LBP. PMID:22514130

  5. Stochastic simulation of patterns using ISOMAP for dimensionality reduction of training images

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Du, Yi; Huang, Tao; Yang, Jiaqing; Li, Xue

    2015-06-01

    Most data in the real world are normally nonlinear or difficult to determine whether they are linear or not beforehand. Some linear dimensionality reduction algorithms, e.g., principal component analysis (PCA) and multi-dimensional scaling (MDS) are only suitable for linear dimensionality reduction of spatial data. The patterns extracted from training images (TIs) used in MPS simulation mostly are probably nonlinear, so for some MPS simulation methods based on dimensionality reduction, e.g., FILTERSIM using some filters created via the idea of PCA and DisPAT using MDS as a tool of dimensionality reduction, those linear methods for dimensionality reduction are not appropriate when realizing the dimensionality reduction of nonlinear data of patterns. Therefore, isometric mapping (ISOMAP) working as a nonlinear dimensionality reduction method used in manifold learning is introduced to map those patterns, regardless of being linear or nonlinear, into low-dimensional space. However, because the original ISOMAP has some disadvantages in computing speed and accuracy, landmark points of patterns are selected to improve the speed and neighborhoods of patterns are set to guarantee the quality of dimensionality reduction. Next, the sequential simulation similar to FILTERSIM is performed after low-dimensional data of patterns are classified by a density-based clustering algorithm. The comparisons with FILTERSIM and DisPAT show the improvement of pattern reproductivity and computing speed of our method for both continuous and categorical variables.

  6. Cloud computing for geophysical applications (Invited)

    NASA Astrophysics Data System (ADS)

    Zhizhin, M.; Kihn, E. A.; Mishin, D.; Medvedev, D.; Weigel, R. S.

    2010-12-01

    Cloud computing offers a scalable on-demand resource allocation model to evolving needs in data intensive geophysical applications, where computational needs in CPU and storage can vary over time depending on modeling or field campaign. Separate, sometimes incompatible cloud platforms and services are already available from major computing vendors (Amazon AWS, Microsoft Azure, Google Apps Engine), government agencies (NASA Nebulae) and Open Source community (Eucalyptus). Multiple cloud platforms with layered virtualization patterns (hardware-platform- software-data-or-everything as a service) provide a feature-rich environment and encourage experimentation with distributed data modeling, processing and storage. However, application and especially database development in the Cloud is different from the desktop and the compute cluster. In this presentation we will review scientific cloud applications relevant to geophysical research and present our results in building software components and cloud services for a virtual geophysical data center. We will discuss in depth economy, scalability and reliability of the distributed array and image data stores, synchronous and asynchronous RESTful services to access and model georefernced data, virtual observatory services for metadata management, and data visualization for web applications in Cloud.

  7. Cloud cover analysis with Arctic Advanced Very High Resolution Radiometer data. II - Classification with spectral and textural measures

    NASA Technical Reports Server (NTRS)

    Key, J.

    1990-01-01

    The spectral and textural characteristics of polar clouds and surfaces for a 7-day summer series of AVHRR data in two Arctic locations are examined, and the results used in the development of a cloud classification procedure for polar satellite data. Since spatial coherence and texture sensitivity tests indicate that a joint spectral-textural analysis based on the same cell size is inappropriate, cloud detection with AVHRR data and surface identification with passive microwave data are first done on the pixel level as described by Key and Barry (1989). Next, cloud patterns within 250-sq-km regions are described, then the spectral and local textural characteristics of cloud patterns in the image are determined and each cloud pixel is classified by statistical methods. Results indicate that both spectral and textural features can be utilized in the classification of cloudy pixels, although spectral features are most useful for the discrimination between cloud classes.

  8. Multiline spectral imaging of dense cores in the Lupus molecular cloud

    NASA Astrophysics Data System (ADS)

    Benedettini, M.; Pezzuto, S.; Burton, M. G.; Viti, S.; Molinari, S.; Caselli, P.; Testi, L.

    2012-01-01

    The molecular clouds Lupus 1, 3 and 4 were mapped with the Mopra Telescope at 3 and 12 mm. Emission lines from high-density molecular tracers were detected, i.e. NH3 (1,1), NH3 (2,2), N2H+ (1-0), HC3N (3-2), HC3N (10-9), CS (2-1), CH3OH (20-10)A+ and CH3OH (2-1-1-1)E. Velocity gradients of more than 1 km s-1 are present in Lupus 1 and 3, and multiple gas components are present in these clouds along some lines of sight. Lupus 1 is the cloud richest in high-density cores: eight cores were detected in it, five cores were detected in Lupus 3 and only two in Lupus 4. The intensity of the three species HC3N, NH3 and N2H+ changes significantly in the various cores: cores that are brighter in HC3N are fainter or undetected in NH3 and N2H+ and vice versa. We found that the column density ratios HC3N/N2H+ and HC3N/NH3 change by 1 order of magnitude between the cores, indicating that also the chemical abundance of these species is different. The time-dependent chemical code that we used to model our cores shows that the HC3N/N2H+ and HC3N/NH3 ratios decrease with time, therefore the observed column density of these species can be used as an indicator of the chemical evolution of dense cores. On this basis we classified five out of eight cores in Lupus 1 and one out of five cores in Lupus 3 as very young protostars or pre-stellar cores. Comparing the millimetre core population with the population of the more evolved young stellar objects identified in the Spitzer surveys, we conclude that in Lupus 3 the bulk of the star formation activity has already passed and only a moderate number of stars are still forming. In contrast, in Lupus 1 star formation is ongoing and several dense cores are still in the pre-/protostellar phase. Lupus 4 is at an intermediate stage, with a smaller number of individual objects.

  9. Parameter Estimation of Fossil Oysters from High Resolution 3D Point Cloud and Image Data

    NASA Astrophysics Data System (ADS)

    Djuricic, Ana; Harzhauser, Mathias; Dorninger, Peter; Nothegger, Clemens; Mandic, Oleg; Szkely, Balzs; Molnr, Gbor; Pfeifer, Norbert

    2014-05-01

    A unique fossil oyster reef was excavated at Stetten in Lower Austria, which is also the highlight of the geo-edutainment park 'Fossilienwelt Weinviertel'. It provides the rare opportunity to study the Early Miocene flora and fauna of the Central Paratethys Sea. The site presents the world's largest fossil oyster biostrome formed about 16.5 million years ago in a tropical estuary of the Korneuburg Basin. About 15,000 up to 80-cm-long shells of Crassostrea gryphoides cover a 400 m2 large area. Our project 'Smart-Geology for the World's largest fossil oyster reef' combines methods of photogrammetry, geology and paleontology to document, evaluate and quantify the shell bed. This interdisciplinary approach will be applied to test hypotheses on the genesis of the taphocenosis (e.g.: tsunami versus major storm) and to reconstruct pre- and post-event processes. Hence, we are focusing on using visualization technologies from photogrammetry in geology and paleontology in order to develop new methods for automatic and objective evaluation of 3D point clouds. These will be studied on the basis of a very dense surface reconstruction of the oyster reef. 'Smart Geology', as extension of the classic discipline, exploits massive data, automatic interpretation, and visualization. Photogrammetry provides the tools for surface acquisition and objective, automated interpretation. We also want to stress the economic aspect of using automatic shape detection in paleontology, which saves manpower and increases efficiency during the monitoring and evaluation process. Currently, there are many well known algorithms for 3D shape detection of certain objects. We are using dense 3D laser scanning data from an instrument utilizing the phase shift measuring principle, which provides accurate geometrical basis < 3 mm. However, the situation is difficult in this multiple object scenario where more than 15,000 complete or fragmentary parts of an object with random orientation are found. The goal is to investigate if the application of state-of-the-art 3D digitizing, data processing, and visualization technologies support the interpretation of this paleontological site. The obtained 3D data (approx. 1 billion points at the respective area) is analyzed with respect to their 3D structure in order to derive geometrical information. The aim of this contribution is to segment the 3D point cloud of laser scanning data into meaningful regions representing particular objects. Geometric parameters (curvature, tangent plane orientation, local minimum and maximum, etc.) are derived for every 3D point of the point cloud. A set of features is computed in each point using different kernel sizes to define neighborhoods of different size. This provides information on convexity (outer surface), concavity (inner surface) and locally flat areas, which shall be further utilized in fitting model of Crassostrea-shells. In addition, digitizing is performed manually in order to obtain a representative set of reference data for the evaluation of the obtained results. For evaluating these results the reference data (length and orientation of specimen) is then compared to the automatically derived segments of the point cloud. The study is supported by the Austrian Science Fund (FWF P 25883-N29).

  10. Hyperspectral simulation of chemical weapon dispersal patterns using DIRSIG

    NASA Astrophysics Data System (ADS)

    Arnold, Peter S.; Brown, Scott D.; Schott, John R.

    2000-07-01

    Fieldable thermal infrared hyperspectral imaging spectrometers has made it possible to design and construct new instruments for better detection of battlefield hazards such as chemical weapon clouds. The availability of spectroscopic measurements of these clouds can be used not only for the detection and identification of specific chemical agents but also to potentially quantify the lethality of the cloud. The simulation of chemical weapon dispersal patterns in a synthetic imaging environment offers significant benefits to sensor designers. Such an environment allows designers to easily develop trade spaces to test detection and quantification algorithms without the need for expensive and dangerous field releases. This paper discusses the implementation of a generic gas dispersion model that has been integrated into the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model. The gas cloud model utilizes a 3D Gaussian distribution and first order dynamics (drift and dispersion) to drive the macro-scale cloud development and movement. The model also attempts to account for turbulence by incorporating fractional Brownian motion techniques to reproduce the micro-scale variances within the cloud. The cloud path length concentrations are then processed by the DIRSIG radiometry sub-model to compute the emission and transmission of the cloud body on a per-pixel basis. Example hyperspectral image cubes containing common agents and release amounts will be presented. Time lapse sequences will also be presented to demonstrate the evolution of the cloud over time.

  11. Analysis of micro-contact printed protein patterns by SPR imaging with a LED light source.

    PubMed

    Wilkop, Thomas; Wang, Zhuangzhi; Cheng, Quan

    2004-12-01

    We demonstrate the characterization of mu-contact printed protein patterns and analysis of protein-protein interactions by two-dimensional (2-D) surface plasmon resonance imaging (SPRi). Advancements in SPRi image quality from employing a light emitting diode (LED) as the light source are described. We show that a LED offers an ideal point source that can eliminate interference artifacts and speckles found when using a laser source. The attainable thickness resolution in fixed-angle imaging is comparable to that of a monochromatic source, providing a solid foundation for quantitative analysis with the system. The SPR imaging technique reported here affords sub-nanometer thickness sensitivity and micrometer lateral resolution, allowing for convenient studies of biomolecular interactions and surface morphologies of ultrathin films. Spatially well-defined protein patterns of bacterial toxins were obtained by microcontact printing using a polydimethylsiloxane (PDMS) stamp on a functionalized self-assembled monolayer on Au. The influence of protein concentration in the inking solution on transfer efficiency was investigated, and a nonlinear correlation was observed between the solution concentration and the amount of protein immobilized on the surface. Quantitative analysis of protein interaction was performed with toxin-specific antibody, showing a concentration-dependent relationship that verifies the retention of biological activity of the protein after printing. The study demonstrates the feasibility and effectiveness of using LEDs as light sources in SPR imaging, opening doors for developing compact SPR instruments for direct, sensitive, and label-free detection of biohazardous molecules. PMID:15568869

  12. Influence of permittivity and electrical conductivity on image pattern of MRI.

    PubMed

    Harimoto, Takashi; Ohno, Seiichiro; Hattori, Kengo; Hirosue, Miyuki; Miyai, Masahiro; Shibuya, Koichi; Kuroda, Masahiro; Kanazawa, Susumu; Kato, Hirokazu

    2013-01-01

    In proton density-weighted (PDW) MR imaging, the patterns of signal intensity vary depending on the imaged material, and change with the flip angle (FA) applied to the imaged material. The correlation between the pre-determined FA and the actual FA applied to imaged objects was investigated using 4 types of phantoms having different dielectric properties. PDW images were acquired using the spin-echo (SE) method and different pre-determined FA. Dependency of the signal intensity distribution in the phantom on the pre-determined FA differed among phantoms: patterns for water and 0.402 w/w% saline solution phantoms changed with the pre-determined FA, whereas those for olive oil and 4.02 w/w% saline solution phantoms were barely affected by the pre-determined FA. Causes of these phenomena were considered to be the differences between the pre-determined FA and the actual FA among the phantoms; differences were also influenced by the positioning of the phantom. Our study showed that the actual FA in the phantom is greater than the pre-determined FA in high permittivity media, whereas it is reduced by an increased conductivity of the media. PMID:23694908

  13. The object image reconstruction from the speckle pattern of its field

    SciTech Connect

    Bel'dyugin, Igor M; Zubarev, I G; Mikhailov, S I

    2001-06-30

    It is shown that information on the speckle pattern allows one to form a kind of the resonator with a minimum-loss mode representing the required image. The image reconstruction process is simulated for a variety of objects. The outlook for the building of astronomical instruments, which are equivalent to modern telescopes and are based on the principle of detection and processing of information contained in the speckle field scattered by an object, are discussed. (laser applications and other topics in quantum electronics)

  14. Learning the histogram sequences of generalized local ternary patterns for blind image quality assessment

    NASA Astrophysics Data System (ADS)

    Yan, Yaping; Du, Songlin; Zhang, Hongjuan; Ma, Yide

    2015-12-01

    The local binary pattern (LBP) has been proved to be significantly useful and competitive in the application of blind image quality assessment (BIQA). However, LBP is short of magnitude information, limiting its performance to some extent. In this paper, we introduce a novel BIQA method, which uses the proposed generalized local ternary pattern (GLTP) to measure structural degradation. By introducing multi-threshold for the gray-level differences, GLTP can provide more discriminative and stable features. Moreover, GLTP contains magnitude information computed by using the magnitudes of horizontal and vertical first-order derivatives. Experimental results on two subject-rated databases demonstrate that the proposed method outperforms state-of-the-art BIQA models, as well as several representative full reference image quality assessment methods for various types of distortions.

  15. Detecting melanoma in dermoscopy images using scale adaptive local binary patterns.

    PubMed

    Riaz, Farhan; Hassan, Ali; Javed, Muhammad Younis; Tavares Coimbra, Miguel

    2014-01-01

    Recent advances in the area of computer vision has led to the development of various assisted diagnostics systems for the detection of melanoma in the patients. Texture and color are considered as two fundamental visual characteristics which are vital for the detection of melanoma. This paper proposes the use of a combination of texture and color features for the classification of dermoscopy images. The texture features consist of a variation of local binary pattern (LBP) in which the strength of the LBPs is used to extract scale adaptive patterns at each pixel, followed by the construction of a histogram. For color feature extraction, we used standard HSV histograms. The extracted features are concatenated to form a feature vector for an image, followed by classification using support vector machines. Experiments show that the proposed feature set exhibits good classification performance comparing favorably to other state-of-the-art alternatives. PMID:25571547

  16. Magneto-optical imaging of magnetic domain pattern produced by intense femtosecond laser pulse irradiation

    NASA Astrophysics Data System (ADS)

    Sinha, Jaivarhan; Mohan, Shyam; Banerjee, S. S.; Kahaly, S.; Kumar, G. Ravindra

    2009-03-01

    An important and intriguing area of research is laser plasma generated giant magnetic field pulses. Interaction of ultrashort high intensity laser pulses with matter involves several mechanisms for generating ultrastrong magnetic fields. By irradiating a magnetic recordable tape constituting of ?-Fe2O3 particles with an intense p-polarized femtosecond laser pulses ( 10^16 W cm-2, 100fs), we have found complex magnetic field patterns stored in the tape. We image the local magnetic field distribution around the irradiated region [1] using the high sensitivity magneto-optical imaging technique. We understand the complex magnetic domains patterns recoded on the tape in terms of interesting instabilities [1] generated in the plasma produced during the irradiation of the tape with intense laser pulses. [0pt] [1] Jaivardhan Sinha, Shyam Mohan, S. S Banerjee, S. Kahaly, G. Ravindra Kumar, Phys. Rev. E 77, 046118(2008). *satyajit@iitk.ac.in

  17. Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging.

    PubMed

    Nadeau, Kyle P; Rice, Tyler B; Durkin, Anthony J; Tromberg, Bruce J

    2015-11-01

    We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI. PMID:26524682

  18. Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging

    NASA Astrophysics Data System (ADS)

    Nadeau, Kyle P.; Rice, Tyler B.; Durkin, Anthony J.; Tromberg, Bruce J.

    2015-11-01

    We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI.

  19. Soil transference patterns on bras: Image processing and laboratory dragging experiments.

    PubMed

    Murray, Kathleen R; Fitzpatrick, Robert W; Bottrill, Ralph S; Berry, Ron; Kobus, Hilton

    2016-01-01

    In a recent Australian homicide, trace soil on the victim's clothing suggested she was initially attacked in her front yard and not the park where her body was buried. However the important issue that emerged during the trial was how soil was transferred to her clothing. This became the catalyst for designing a range of soil transference experiments (STEs) to study, recognise and classify soil patterns transferred onto fabric when a body is dragged across a soil surface. Soil deposits of interest in this murder were on the victim's bra and this paper reports the results of anthropogenic soil transfer to bra-cups and straps caused by dragging. Transfer patterns were recorded by digital photography and photomicroscopy. Eight soil transfer patterns on fabric, specific to dragging as the transfer method, appeared consistently throughout the STEs. The distinctive soil patterns were largely dependent on a wide range of soil features that were measured and identified for each soil tested using X-ray Diffraction and Non-Dispersive Infra-Red analysis. Digital photographs of soil transfer patterns on fabric were analysed using image processing software to provide a soil object-oriented classification of all soil objects with a diameter of 2 pixels and above transferred. Although soil transfer patterns were easily identifiable by naked-eye alone, image processing software provided objective numerical data to support this traditional (but subjective) interpretation. Image software soil colour analysis assigned a range of Munsell colours to identify and compare trace soil on fabric to other trace soil evidence from the same location; without requiring a spectrophotometer. Trace soil from the same location was identified by linking soils with similar dominant and sub-dominant Munsell colour peaks. Image processing numerical data on the quantity of soil transferred to fabric, enabled a relationship to be discovered between soil type, clay mineralogy (smectite), particle size and soil moisture content that would not have been possible otherwise. Soil type (e.g. Anthropogenic, gravelly sandy loam soil or Natural, organic-rich soil), clay mineralogy (smectite) and soil moisture content were the greatest influencing factors in all the dragging soil transference tests (both naked eye and measured properties) to explain the eight categories of soil transference patterns recorded. This study was intended to develop a method for dragging soil transference laboratory experiments and create a baseline of preliminary soil type/property knowledge. Results confirm the need to better understand soil behaviour and properties of clothing fabrics by further testing of a wider range of soil types and clay mineral properties. PMID:26679633

  20. Jupiter's High-Altitude Clouds

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons Multispectral Visible Imaging Camera (MVIC) snapped this incredibly detailed picture of Jupiter's high-altitude clouds starting at 06:00 Universal Time on February 28, 2007, when the spacecraft was only 2.3 million kilometers (1.4 million miles) from the solar system's largest planet. Features as small as 50 kilometers (30 miles) are visible. The image was taken through a narrow filter centered on a methane absorption band near 890 nanometers, a considerably redder wavelength than what the eye can see. Images taken through this filter preferentially pick out clouds that are relatively high in the sky of this gas giant planet because sunlight at the wavelengths transmitted by the filter is completely absorbed by the methane gas that permeates Jupiter's atmosphere before it can reach the lower clouds.

    The image reveals a range of diverse features. The south pole is capped with a haze of small particles probably created by the precipitation of charged particles into the polar regions during auroral activity. Just north of the cap is a well-formed anticyclonic vortex with rising white thunderheads at its core. Slightly north of the vortex are the tendrils of some rather disorganized storms and more pinpoint-like thunderheads. The dark 'measles' that appear a bit farther north are actually cloud-free regions where light is completely absorbed by the methane gas and essentially disappears from view. The wind action considerably picks up in the equatorial regions where giant plumes are stretched into a long wave pattern. Proceeding north of the equator, cirrus-like clouds are shredded by winds reaching speeds of up to 400 miles per hour, and more pinpoint-like thunderheads are visible. Although some of the famous belt and zone structure of Jupiter's atmosphere is washed out when viewed at this wavelength, the relatively thin North Temperate Belt shows up quite nicely, as does a series of waves just north of the belt. The north polar region of Jupiter in this image has a mottled appearance, and the scene is not as dynamic as the equatorial and south polar regions.

    The intricate structures revealed in this image are exciting, but they are only part of the story. The New Horizons instruments have taken images of Jupiter at approximately 260 different wavelengths, providing essentially a three-dimensional view of Jupiter's atmosphere, since images at different wavelengths probe different altitudes. New Horizons is providing a wealth of data on this fascinating planet during this last close-up view of Jupiter until the middle of the next decade.