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  • EARTH RESOURCES AND REMOTE SENSING  (6,923)
  • ASTROPHYSICS  (5,125)
  • 2010-2014
  • 1980-1984  (6,247)
  • 1975-1979  (5,801)
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  • 1
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    In:  CASI
    Publication Date: 2009-11-16
    Description: Background information and exercises are provided to: (1) establish or expand understanding of the concepts, methods, and terminology of computer processing of image producing data; (2) develop insight into the advantages of computer based image processing compared with the photointerpretation approach for processing, classifying, interpreting, and applying remote sensing data; (3) foster a broad perspective on the principal of the main techniques for image enhancement, pattern recognition, and thematic classification; (4) appreciate the pros and cons of batch and interactive modes of image analysis; (5) examine and evaluate some specific computer generated products for subscenes in Pennsylvania and New Jersey; and (6) interrelate these particular examples of output with more theoretical explanations of computer processing strategies and procedures.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 145-232
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  • 2
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    In:  CASI
    Publication Date: 2006-08-09
    Description: Observations of cosmic and gamma radiation by SAS-2 satellite are summarized and analyzed to determine processes responsible for producing observed galactic radiation. In addition to the production of gamma rays in discrete galactic objects such as pulsars, there are three main mechanisms by which high-energy (greater than 100 MeV) radiation is produced by high-energy interactions involving cosmic rays in interstellar space. These processes, which produce what may be called diffuse galactic gamma-rays, are: (1) the decay of pi mesons produced by interactions of cosmic ray nucleons with interstellar gas nuclei; (2) the bremsstrahlung radiation produced by cosmic ray electrons interacting in the Coulomb fields of nuclei of interstellar gas atoms; and (3) Compton interactions between cosmic ray electrons and low-energy photons in interstellar space.
    Keywords: ASTROPHYSICS
    Type: The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 315-346
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  • 3
    Publication Date: 2006-08-09
    Description: Gamma ray astronomy is now beginning to provide a new look at the galactic structure and the distribution of cosmic rays, both electrons and nucleons, within the galaxy. The observations are consistent with a galactic spiral-arm model in which the cosmic rays are linearly coupled to the interstellar gas on the scale of the spiral arms. The agreement between the predictions of the model and the observations for regions of the plane where both 21-cm and 2.6-mm CO surveys exist emphasizes the need to extend these observations to include the entire plane. Future gamma-ray observations with more sensitivity and better angular resolutions, combined with these radio surveys, should shed new light on the distribution of cosmic rays, the nature of the galaxy, and the location and intensity of the spiral arms.
    Keywords: ASTROPHYSICS
    Type: The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 301-314
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  • 4
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    In:  CASI
    Publication Date: 2006-08-09
    Description: The density distributions of pulsars in luminosity, period, Z-distance, and galactocentric distance were derived, using a uniform sample of pulsars detected during a 408-MHz pulsar survey at Jodrell Bank. There are indications of a fine-scale structure in the spatial distributions and evidence that there is a general correlation with other galactic populations and the overall spiral structure. The electron layer in our galaxy is shown to be wider than the pulsar layer and uniform on a large scale. The number of pulsars in the galaxy has been estimated and used to derive the pulsar birthrate.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 265-282
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  • 5
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    In:  CASI
    Publication Date: 2006-08-09
    Description: Thermal radiation associated with the explosion of supernovae is investigated. High temperature is required to produce copious gamma radiation of this sort. It appears that type 11 supernovae do not release much of their energy as gamma ray continuum radiation.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 257-264
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  • 6
    Publication Date: 2006-08-09
    Description: The degree of saturation characterizing low altitude emission observations of H(I) and the optical depth corrections to the derived column and volume densities are discussed. The amount of fine-scale velocity and spatial structure diluted by the instrumental limitations of the presently available surveys are described. The general problem of detailed mapping of H(I) in the galaxy is explored. Comparison is made between the distribution of H(I) and that of CO and several other galactic tracers. Atomic hydrogen is unique in its distribution, instead of being typical of many Population I constituents. As defined by atomic hydrogen, the galactic disk has a diameter fully twice as large as that defined by the ionized and molecular states of hydrogen, as well as by other molecules, supernova remnants, pulsars, gamma-radiation, synchroton radiation, and the youngest stars. It is also less confined to the galactic equator than most of the other constituents. The degree of small scale structure apparent in the molecular observations is much greater than that in the H(I) observations.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 163-188
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  • 7
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    In:  CASI
    Publication Date: 2006-08-09
    Description: Data from the SAS-2 high-energy gamma-ray experiment reveal the existence of four pulsars emitting photons above 35 MeV. An attempt is made to explain the gamma-ray emission from these pulsars in terms of an electron-photon cascade that develops in the magnetosphere of the pulsar. Although there is very little material above the surface of the pulsar, the very intense magnetic fields (10 to the 12th power gauss) correspond to many radiation lengths which cause electrons to emit photons by magnetic bremsstrahlung and which cause these photons to pair-produce. The cascade develops until the mean photon energy drops below the pair-production threshold which is in the gamma-ray range; at this stage, the photons break out from the source.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 109-118
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  • 8
    Publication Date: 2006-08-09
    Description: Considerations made in developing a model of pulsars are explored. Observational data seems to support the argument that pulsar magnetospheres may contain large masses of plasma. The cascade process resulting from pair creation enables one to interpret the X-ray emission from the Crab and Vela pulsars as synchrotron radiation. On the other hand, the optical radiation from the Crab pulsar is best understood as coherent curvature radiation. Radio emission is interpreted as curvature radiation produced by charge bunches moving along magnetic-field lines. Certain tests of this model are proposed.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 99-108
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  • 9
    Publication Date: 2006-04-06
    Description: Isolated knobs that are erosional remnants of central volcanoes or of folded rocks occur in several areas of the Altiplano are visible on both optical and images. The optically visible streaks occur in the immediate lee of the knobs, whereas the radar visible streaks occur in the zone downwind between the knobs. Aerial reconnaissance and field studies showed that the optically visible streaks consist of a series of small ( 100 m wide) barchan and barchanoid dunes, intradune sand sheets, and sand hummocks (large shrub coppice dunes) up to 15 m across and 5 m high. On LANDSAT images these features are poorly resolved but combine to form a bright streak. On the radar image, this area also appears brighter than the zone of the radar dark streak; evidently, the dunes and hummocks serve as radar reflectors. The radar dark streak consists of a relatively flat, smooth sand sheet which lacks organized aerolian bedforms, other than occasional ripples. Wind velocity profiles show a greater U value in the optically bright streak zone than in the radar dark streak.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Washington Rept. of Planetary Geology Program, 1983; p 271-272
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  • 10
    Publication Date: 2006-04-06
    Description: The diversity of proposed origins for large Martian outflow channels results from the differing interpretations given to the landforms associated with the outflow channels. In an attempt to help limit the possible mechanisms of channel erosion, detailed studies of three of the channel features were done; the streamlined islands, longitudinal grooves and scour marks. This examination involved a comparison of the martian streamlined islands with various streamlined landforms on Earth including those found in the Channel Scabland in large rivers, glacial drumlins, and desert yardangs. The comparisons included statistical analyses of the landform lengths versus widths and positions of maximum width, and an examination of the degree of shape agreement with the geometric lemniscate which was in turn demonstrated to correspond closely with true airfoil shapes. The analyses showed that the shapes of the martian islands correspond closely to the streamlined islands in rivers and the Channel Scabland land. Drumlins show a much smaller correlation. Erosional rock islands formed by glaciers are very much different in shape.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Washington Rept. of Planetary Geol. Programs; p 200-202
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  • 11
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    In:  CASI
    Publication Date: 2006-02-14
    Description: The specific objectives of this experiment are to establish the population and size distribution of meteoroids in the mass range from 10 to the minus 10 power to 10 to the minus 4 power G, to establish the current population of man-made debris in the same mass range, and to obtain data on the physical properties (composition and density) of meteoroids.
    Keywords: ASTROPHYSICS
    Type: Long Duration Exposure Facility (LDEF); p 136-137
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  • 12
    Publication Date: 2006-02-14
    Description: The objective of this experiment is to study interplanetary dust, variously referred to as cosmic dust, cometary dust, zodiacial dust, or meteoric dust particles. Specific objectives are to obtain information regarding particle mass and velocity, and to undertake correlative analyses with other experiments, both on LDEF or near the time of the LDEF flight.
    Keywords: ASTROPHYSICS
    Type: Long Duration Exposure Facility (LDEF); p 134-135
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  • 13
    Publication Date: 2006-02-14
    Description: The primary objective of this experiment is to investigate the feasibility of future missions of multilayer thin-film detectors acting as energy sorter to collect micrometeoroids, if not in their original shape, at least as fragments suitable for chemical analysis. It is expected that this kind of particle collector will help in solving one of the most puzzling topics in cosmic-dust studies: the mineralogical and chemical composition of the particles. This is a matter of great interest in the study of the origin and evolution of the solar system.
    Keywords: ASTROPHYSICS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 124-126
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  • 14
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    In:  CASI
    Publication Date: 2006-04-18
    Description: Investigation of blue-sensitive photographs of HDE 226868 = Cygnus X-1 reveal no (+ or - 0.06 mag) long-term changes in brightness since the beginning of the century nor any abrupt intensity changes similar to what was observed at X-ray and radio frequencies. From the double sinusoidal fluctuation with 5.6 day period, an attempt is made to derive a more precise value for the orbital period, but problems are encountered and discussed. There exists evidence that the amplitude of the orbital fluctuations is increasing slowly with time.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 513-520
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  • 15
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    In:  CASI
    Publication Date: 2006-04-16
    Description: Images characteristics of geographic regions other than the northeastern part of the United States are presented for interpretation. Pre- and post-eruption imagery of Mt. St. Helens volcano serves to demonstrate the advantages of thermal infrared sensing, and the potential for developing a timely, decision oriented thematic map to be used in solving drought-related problems in Upper Volta is examined to show the applicability of satellite remote sensing in all geographic areas.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 455-475
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  • 16
    Publication Date: 2006-04-12
    Description: The 1980 eruptions of Mount St. Helens in southeast Washington resulted in a pronounced effect on the surface and ground water resources of the state. In response to the volcanic activity, the U.S. Geological Survey intensified statewide surface and ground water sampling programs to determine the nature and magnitude of the volcanic-induced variations. Streams to the east of Mount St. Helens received the major ash fallout. Chemical effects were best noted in smaller streams sampled 60 to 70 miles northeast of Mount St. Helens. The chemical variations observed were pronounced but short lived. Sulfate and chloride increases in anionic composition were prevalent immediately following the eruption; however, the original bicarbonate predominance was again attained within several days. Suspended iron and aluminum concentrations were similarly elevated during the period of greatest ash deposition (highest turbidity); however, the dissolved concentrations remained relatively constant. Depressions of pH were minor and short lived. Streams draining to the south, tributaries to the Columbia river, showed little observable changes in water chemistry. Streams draining to the west (Toutle river and its tributaries) were compositionally affected by the various volcanic activities. Chloride and sulfate anion percentage exceeded the bicarbonate percentage up to one month following the eruption period. Streams and lakes sampled in the immediate vicinity of Mount St. Helens, in addition to trace metals, contained organic compounds derived from decomposing wood buried in the debris deposits. This organic material may constitute a significant source of organic compounds to surface and ground water for some time to come.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Langley Research Center Atmospheric Effects and Potential Climatic Impact of the 1980 Eruptions of Mt. St. Helens; p 43-46
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  • 17
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    In:  CASI
    Publication Date: 2006-04-18
    Description: Spectroscopic observations of Sco X-1 show conclusively that the emission lines vary in radial velocity with a period of .787 sup d + or - .006 and a full range of approximately 120 km/s. The period is identical to that found by Gottleib et al (1975) from photometric data; light minimum occurs when the emission line region is at superior conjunction. The observations indicate that the emission lines originate in an accretion disk surrounding a neutron star which is orbiting about a normal, although somewhat evolved companion. The light variation is due to a heating effect on the non degenerate star, viewed at a small inclination angle.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 683-690
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  • 18
    Publication Date: 2006-04-18
    Description: Data which indicate a periodicity of 17d from Cyg X-3 are reviewed. The data are taken from the Ariel 5 satellite All-Sky Monitor and the Sky Survey Experiment.
    Keywords: ASTROPHYSICS
    Type: X-ray Binaries; p 245-253
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  • 19
    Publication Date: 2006-04-18
    Description: The steep high energy cutoff observed in the spectrum for Her X-1 is analyzed in terms of the severely modified Thomson scattering that dominates the radiative transfer in a highly magnetized plasma near the surface of a neutron star. The data are shown to indicate a field of about 10 to the 13th power G near the magnetic poles and the stopping of accreting matter by nuclear collisions in the neighboring plasma.
    Keywords: ASTROPHYSICS
    Type: X-ray Binaries; p 113-118
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  • 20
    Publication Date: 2006-04-18
    Description: Weak 0.28-keV radiation was observed from Her X-1 5 days before turn-on in the 35 day cycle. The observations were made from an Aerobee rocket. The 0.28-keV intensity is about 1/25 that observed during the on phase. Some evidence for X-rays above 1 keV is also present, and it is possible that the spectrum is different only in intensity from the spectrum in the on phase. The radiation may be X-rays from the vicinity of the neutron star, scattered by ionized material in the inner accretion disk, or may be thermal radiation from the inner accretion disk, or both.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 127-139
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  • 21
    Publication Date: 2006-04-18
    Description: The orbital elements of the 3U 0900-40 binary system were determined by measuring the variations in the arrival times of the 283-second X-ray pulses. The best-fit values of the system parameters and their 95% confidence limits are listed.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 661-667
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  • 22
    Publication Date: 2006-04-18
    Description: From a radial velocity study of lines of He I and the heavier ions of HD 77581 (=Vela X-1), orbital elements for this X-ray binary system are derived. Together with the orbital elements given by Rappaport and McClintock from X-ray pulsar results, this enables determination of masses for both the X-ray and the early type supergiant component.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 643-657
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  • 23
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    In:  CASI
    Publication Date: 2006-04-16
    Description: The benefits-to-cost ratio of satellite remote sensing, both as a substitute for conventional methods of monitoring and assessing resources, and as a supplement to these methods is examined using a model which analyzes the cost of aerial photography versus satellite scanner for producing and interpreting an image of the Earth's surface sized to LANDSAT dimensions. Examples of cost savings are tabulated for ground surveys, aerial photos, and LANDSAT. Possible additional benefits from LANDSAT D are assessed. The way in which satellites fit into more comprehensive models for resources management is discussed. It is shown that remote sensing is but one essential component in a complex system that aggregates technical. Socioeconomics, political, cultural, and other factors in the human decision process.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 389-407
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  • 24
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    In:  CASI
    Publication Date: 2006-04-16
    Description: Computer processing facilitates extraction of information from every pixel by executing a variety of functional operations, called processed algorithms, in general or specialized routines. The best results are obtained when data from more than one multispectral band are used together. Multivariate tatistical analysis, computer tape characteristics, processing modes, and a choice of systems (batch or interactive) are discussed. The major operations in computer processing elaborated include: preprocessing, enhancement, effects of rationing, and classification. Techniques for multisource data correlation are considered with emphasis on geobased systems.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 421-453
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  • 25
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    In:  CASI
    Publication Date: 2006-04-16
    Description: Learning objectives include: (1) developing an understanding of the implications of the term "near surface observations"; (2) associating the appearance of large ground features as seen in satellite imagery with their appearance as seen from the ground; (3) grasping criteria and procedures for selecting training sites on the ground for use in supervised classification; (4) running through an example of training site selection; (5) becoming familiar with several methods of accuracy assessment; (6) becoming aware of the approach and value of making supporting measurements of the spectral and physical properties of materials on the ground and from aircraft; (7) taking note of the different types of instruments used in making specific ground measurements; and (8) appreciating the rationale underlying laboratory and field studies on or near the Earth's surface for the purpose of developing new sensor systems.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 233-276
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  • 26
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    In:  CASI
    Publication Date: 2006-04-16
    Description: Learning objectives include: (1) developing a facility for applying conventional techniques of photointerpretation to small scale (satellite) imager; (2) promoting the ability to locate, identify, and interpret small natural and man made surface features in a LANDSAT image; (3) using supporting imagery, such as aerial and space photography, to conduct specific applications analyses; (4) learning to apply change detection techniques to recognize and explain transient and temporal events in individual or seasonal imagery; (5) producing photointerpretation maps that define major surface units, themes, or classes; (6) classifying or analyzing a scene for specific discipline applications in geology, agriculture, forestry, hyrology, coastal wetlands, and environmental pollution; and (7) evaluating both advantages and shortcomings in relying on the photointerpretive approach (rather than computer based analytical approach) for extracting information from LANDSAT data.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 101-143
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  • 27
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    In:  CASI
    Publication Date: 2006-04-16
    Description: Activities are provided for: (1) developing insight into the way in which the LANDSAT MSS produces multispectral data; (2) promoting understanding of what a "pixel" means in a LANDSAT image and the implications of the term "mixed pixel"; (3) explaining the concept of spectral signatures; (4) deriving a simple signature for a class or feature by analysis: of the four band images; (5) understanding the production of false color composites; (6) appreciating the use of color additive techniques; (7) preparing Diazo images; and (8) making quick visual identifications of major land cover types by their characteristic gray tones or colors in LANDSAT images.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 81-99
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  • 28
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    Publication Date: 2006-04-16
    Description: Learning objectives of the activities provided include: (1) reading the annotation of a LANDSAT image; (2) becoming acquainted with the characteristics of 1:1,000,000 scale transparencies and prints of MSS images; (3) noting the general information visible in LANDSAT photo products; (4) observing changes of appearance of any ground feature or class in the black and white images made from the four MSS bands and the characteristic color of each class in color composites; (5) determining the degree to which a LANDSAT image meets map accuracy standards and can be fitted to map projections; (6) assessing the effects of LANDSAT enlargements and scale changes and of the limitations of satellite resolution relative to aerial photos; (7) observing the influence of time of acquisition (season) on a scene; (8) getting a feel for image quality as dependent on processing and photoreproduction; (9) appreciating the characteristics of the RBV and thermal band imagery obtained from LANDSAT-3; and (10) becoming familiar with certain attributes of adjacent LANDSAT images which permit them to be joined in mosaics and to be viewed in stereo.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 39-80
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  • 29
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    In:  CASI
    Publication Date: 2006-04-18
    Description: There is a standard model for X-ray sources comprising a binary system containing a compact star and powered by mass accretion. It can be argued that the majority and perhaps all the galactic X-ray sources are of this kind. Three kinds of sources which may be qualitatively different from these are discussed: namely, low luminosity sources such as 3U0352 + 30, the sources associated with the globular clusters, and the transient X-ray sources.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 669-676
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  • 30
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    In:  CASI
    Publication Date: 2006-04-18
    Description: It is shown that the broad emission features in the spectrum of HD 153919 are associated with the X-ray secondary and not significantly with the primary star. When the primary is at maximum velocity towards us, the HeI line lambda 4471 develops a blue shifted secondary component with a velocity of -470 km/sec relative to the primary.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 569-574
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  • 31
    Publication Date: 2006-04-18
    Description: Equipotential surfaces incorporating the effect of radiation pressure were computed for the X-ray binaries Cen X-3, Cyg X-1 = HDE 226868, Vela XR-1 = 3U 0900-40 = HD 77581, and 3U 1700-37 = HD 153919. The topology of the equipotential surfaces is significantly affected by radiation pressure. In particular, the so-called critical Roche (Jacobian) lobes, the traditional figure 8's, do not exist. The effects of these results on modeling X-ray binaries are discussed.
    Keywords: ASTROPHYSICS
    Type: X-ray Binaries; p 499-511
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  • 32
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    In:  CASI
    Publication Date: 2006-04-18
    Description: Absorbing material in Cygnus X-1 jitters near the line joining the two stars, out of the orbital plane is described. Three looks with the Copernicus satellite at Cygnus X-1 have produced four examples of absorption dips (decreases in the 2 to 7 keV flux from Cygnus X-1 with an increase of spectral hardness consistent with photoelectric absorption).
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 425-427
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  • 33
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    In:  CASI
    Publication Date: 2006-04-18
    Description: Radio observations of Cyg X-1 (HDE 226868) taken during the period May-June 1975 at 2,695 and 8,085 MHz are presented and discussed in the context of both the previous four years of data at these frequencies and subsequent data for September-October 1975. The data show that the radio event was a transient one with a time scale of the order of a few to several weeks, and that the observed radio decay was qualitatively similar to the observed decay of the enhanced X-ray state.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 495-497
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  • 34
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    In:  CASI
    Publication Date: 2006-04-16
    Description: The primary LANDSAT mission and the system requirements are summarized and pertinent parameters of the spacecraft, its orbit, and payload are tabulated. The history acquisition to entry into the archives for storage and product generation and dissemination is recounted. The LANDSAT D data handling plan is discussed showing requirements for both the MSS CCT and the thematic mapper CCT.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 409-419
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  • 35
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    In:  CASI
    Publication Date: 2006-04-16
    Description: The term remote sensing is defined as well as ideas such as class, pattern, feature, pattern recognition, feature extraction, and theme. The electromagnetic spectrum is examined especially those wavelength regions available to remote sensing. Relevant energy and wave propagation laws are discussed and the characteristics of emitted and reflected radiation and their detection are investigated. The identification of classes by their spectral signatures, the multispectral approach, and the principal types of sensors and platforms used in remote sensing are also considered.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 9-38
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  • 36
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    In:  CASI
    Publication Date: 2006-06-04
    Description: Operation of the microwave instrument as a two frequency scatterometer, a synthetic aperture radar, and a passive microwave radiometer is planned. Operation of the instrument in each of its three modes is discussed and the antenna system described.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 3 p
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  • 37
    Publication Date: 2006-01-12
    Description: Observations of the galactic longitude and latitude distributions of gamma = 2.6 mm CO emission are presented. Analysis of this spectral line data yields the large scale distribution of molecular clouds in the galactic disk and their z-distribution out of the disk. Strong maxima in the number of molecular clouds occur in the galactic nucleus and at galactic radii 4-8 kpc. The peak at 4-8 kpc correlates well with a region of enhanced 100 Mev gamma ray emissivity. This correlation strongly supports the conclusion that the gamma rays are produced as a result of cosmic ray interactions in molecular H2 clouds rather than HI. One important implication of this is that the interstellar magnetic field lines to which cosmic rays are confined must therefore not be excluded from these dense clouds. The width of the cloud layer perpendicular to galactic plane between half density points is 105 + or - 15 pc near the 5.5 kpc peak. The total mass of molecular gas in the interior of the galaxy exceeds that of atomic hydrogen.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 163-176
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  • 38
    Publication Date: 2006-01-12
    Description: With the launch of LANDSAT-1 in July 1972, and the follow-on launch of LANDSAT-2 in January of this year, routine availability of satellite imagery and electronic data of the earth's resources has become a reality. Federal data centers provide LANDSAT data to resource managers and the general public. These data centers have to date provided almost 500,000 frames of LANDSAT data at a cost of more than $2,000,000. Data from the LANDSAT satellite program, along with data and information from the Skylab manned program, are available over any location to anyone for the cost of reproduction.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 372-378
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  • 39
    Publication Date: 2006-01-12
    Description: Aerial photographs of the entire state were used to develop information on geomorphic regions, land ownership, forest cover, soils, geology, land classification and land capability. LANDSAT imagery was included to update many photomaps for land use classification and urban development planning.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 340-350
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  • 40
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    Publication Date: 2006-01-12
    Description: Joint Federal/State remote data sensing centers are advocated to help survey Alaska for land use planning by aerial photography and LANDSAT imagery. The centers are to provide satellite derived information in land use planning and offshore oil developments.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 315-318
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  • 41
    Publication Date: 2006-01-12
    Description: The experience of the Ohio-Kentucky-Indiana Regional Council of Governments in its development of a regional land use inventory from computer processing of LANDSAT 1 digital tapes and the use of those data in the OKI water quality planning program are discussed. A major part of the planning program is the prediction of water quality in rivers and lakes resulting from existing and future land uses. A model has been developed that can predict the flow of sediment, total phosphorus, total nitrogen, and organic wastes into major streams. An essential input to this model is an accurate map of land use derived from LANDSAT 1 digital tapes.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 356-358
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  • 42
    Publication Date: 2006-01-12
    Description: Registration of remotely sensed data to geodetic coordinates provides for overlay analysis of land use data. For aerial photographs of a large area, differences in scales, dates, and film types are reconciled, and multispectral scanner data are machine registered at the time of acquisition.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 319-325
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  • 43
    Publication Date: 2006-01-12
    Description: Aerial and fixed platform oil spill detection systems primarily utilize remote sensors for data acquisition and pollution monitoring purposes. In addition to aerial photography and infrared reflectance sensors, a laser backscatter sensor and an ultraviolet fluorescence sensor are considered for application in pollution surveillance systems.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 271-279
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  • 44
    Publication Date: 2006-01-12
    Description: It is shown that remotely sensed data, whether in digital or imagery form, provide objective, systematic measurements of coastal zone characteristics when compared with traditional measurement techniques. An example is given for Alabama shoreline parameters using LANDSAT 1 composite mapping.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 224-231
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  • 45
    Publication Date: 2006-01-12
    Description: Satellite gathered remote sensor data were used to update a basic environmental atlas of southern Louisiana to reflect recent dynamic geological changes, such as erosion by wave action along the coast and active delta building in the lower part of the Mississippi Basin. Standard pattern recognition programs were utilized to update LANDSAT pictures for three categories (generalized land use, ecological zones and vegetation) to obtain a simulated color photomap for LANDSAT frames for further rectification by a table lookup program.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA Earth Resources Survey Symp., Vol. 2-B; p 217-223
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  • 46
    Publication Date: 2006-01-12
    Description: The primary objectives of the earth observations and photography experiment of the Apollo Soyuz Test Project were to photograph various terrestrial structures and to use the capabilities of man as a trained observer in visually studying earth features and phenomena. Man's special capabilities include the sensitivity of the eye to subtle color variations and the speed with which the eye/brain system can interpret what is seen and select targets for photography. Real time astronaut observations constitute a useful complement to orbital photographs and greatly aid in their interpretation. Targets for mapping and hand held photography were selected on the basis of their value to specialists in the earth sciences including geology, oceanography, desert study, hydrology, meteorology, and environmental science.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center Apollo-Soyuz Test Project; 64 p
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  • 47
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    Publication Date: 2006-01-16
    Description: The use of the Space Telescope in the determination of the distances of galaxies is examined. The Space Telescope can check the local extragalactic distance scale to within 10-15 percent. The determination of relative distances of cosmic standard candles, viz. brightest M-supergiants and SNe I in E galaxies, is discussed. The M-supergiants map the velocity field out to v sub o approx. 3000 km s(-1) thus providing a firm basis for the determination of H sub o (global) from local distances, and the possibility to derive precise distances of all nearby field galaxies from their recession velocities. Photometry of the SNe I out to z = 0.5 leads to a direct determination of q sub o via the Hubble diagram, and the form of their light curves offers a fundamental test on the nature of redshifts. Other calculations are discussed.
    Keywords: ASTROPHYSICS
    Type: NASA. Marshall Space Flight Center Sci. Res. with the Space Telescope; p 263-293
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  • 48
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    Publication Date: 2006-01-12
    Description: Observations of the diffuse far infrared flux from the galactic plane as well as far infrared measurements of the properties of dense molecular clouds, when combined with recent high-energy gamma ray measurements and radio observations of carbon monoxide, can yield new information about the total mass of molecular clouds, the large scale structure of the inner galaxy, and the density of cosmic rays. These observations are discussed.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 222-238
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  • 49
    Publication Date: 2006-01-12
    Description: A statewide computerized land use mapping system is reported that uses polygons to identify inventories from aerial photography by employing the USGS classification system. In addition, the system provides soil, population, and housing census data as well as economic indicators that can be useful in relating to the overall system.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 326-339
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  • 50
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    In:  CASI
    Publication Date: 2006-01-12
    Description: Orthophotoquads prepared from high altitude photography and LANDSAT imagery were utilized for land use mapping and urban development planning. LANDSAT imagery of rough terrains were evaluated by photographic projection on a viewer screen for enlargement of details.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 300-314
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  • 51
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    Publication Date: 2006-01-12
    Description: Remote panchromatic imagery was applied to develop a coastal zone management atlas that provides for land cover or vegetation surveys as well as land use stereographic mapping for regional planning purposes.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA Earth Resources Survey Symp., Vol. 2-B; p 173-175
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  • 52
    Publication Date: 2006-01-12
    Description: A computer derived land use classification scheme for infrared LANDSAT imagery was developed and applied to update existing Mississippi coastline data. Inventory classifications were accomplished by photographic enlargement and photointerpretations showing color coded resources on the ground.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 282-290
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  • 53
    Publication Date: 2006-01-12
    Description: Land use maps were developed from photomaps obtained by remote sensing in order to develop a comprehensive state plan for the protection, development, and zoning of coastal regions. Only photographic remote sensors have been used in support of the coastal council's planning/management methodology. Standard photointerpretation and cartographic application procedures for map compilation were used in preparing base maps.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 232-241
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  • 54
    Publication Date: 2006-01-12
    Description: During the oceanic period from July to November, the southward flowing California current dominates the nearshore current patterns. Commencing about the middle of November and extending to mid-February, the Davidson current, a northward moving countercurrent, is the dominant inshore transporter of water and suspensates. The phenomenon of upwelling is prevalent during the period from the middle of February to the end of July. Thus, every year along the coast of California, there are three successive current seasons: the oceanic, the Davidson, and the upwelling. This paper is a discussion of the nature of these nearshore currents. In addition, the capabilities of various remote sensing platforms and systems for providing methods of monitoring the coastal processes associated with the current seasons of California are demonstrated herein.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 195-216
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  • 55
    Publication Date: 2006-01-12
    Description: Digital data from the infrared LANDSAT imagery were used to classify eutrophication levels of lakes in an effort to observe the effect of thermal discharges from power stations. LANDSAT data were also applied to identify and monitor wetlands, for soil surveys, sedimentation transport, and in general to assist in land use planning and resources management.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 291-296
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  • 56
    Publication Date: 2006-01-12
    Description: Digital processing of multispectral LANDSAT data was used to develop a computerized model for predicting oil slick movement within the Delaware Bay. LANDSAT imagery was also used to monitor offshore waste disposal sites for mapping of wetlands, and charting of tidal currents.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 188-194
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  • 57
    Publication Date: 2006-01-12
    Description: Remote sensing techniques provide important information for land and water use planning organizations in order to assess coastal developments and their impact on water resources, sediment transport, erosion, and marine biology. Political expediency requires pertinent data acquisition and data dissemination to local populations for coastal zone management decision making.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA Earth Resources Survey Symp., Vol. 2-B; p 176-187
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  • 58
    Publication Date: 2006-01-12
    Description: The operational feasibility of using remote sensing to provide all weather ice formation for Great Lakes winter navigation is explored. A combination airborne pulsed radar system to measure actual ice thickness, a satellite data link system, and a hand drawn interpretive ice chart proved valuable for extending winter navigation through the icepack.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA Earth Resources Survey Symp., Vol. 2-B; p 261-270
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  • 59
    Publication Date: 2006-01-16
    Description: Physical processes within quiescent as well as disturbed flows of solar wind plasma, energetic particles, and magnetic and electric fields from the Sun are considered. Specifically, travelling interplanetary phenomena to be studied during the years of the solar maximum of solar cycle 21 are covered. It is noted that predictions, while needed for long range, logistical planning, is secondary to the requirements of synoptic real time monitoring over a wide range of particle energies and spectral bandwidths.
    Keywords: ASTROPHYSICS
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 340-345
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  • 60
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    Publication Date: 2006-02-14
    Description: Results associated with exact solution of the Einstein-Boltzmann and Einstein-Maxwell-Boltzmann equations are presented. The generalization of Ehler's killing vector approach for the distribution function to charged particles is considered.
    Keywords: ASTROPHYSICS
    Type: Alabama Univ. in Huntsville The 1981 NASA(ASEE Summer Fac. Fellowship Program; 21 p
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  • 61
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    Publication Date: 2006-01-12
    Description: From satellite measurements of ultraviolet spectra of stars, an average density of approximately 1.1/cu cm for hydrogen atoms, in both atomic and molecular form, is estimated for regions of space along the galactic plane within about 1 kpc of the sun. About 20% of the atoms are bound in molecular form although this figure is uncertain since the ultraviolet measurements avoid the very dense interstellar clouds. Discrete values for this percentage are observed to vary markedly; regions with less than average density seem to have fractional abundances of H2 several orders of magnitude lower than average. A ratio of CO/H is observed for regions in front of stars observed by the Copernicus satellite.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 239-263
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  • 62
    Publication Date: 2006-01-12
    Description: Several current problems concerning the overall distribution of hydrogen in the galaxy are discussed in general terms. These problems include the degree of saturation characterizing low-latitude emission observations of HI, and the optical-depth corrections to the derived column and volume densities; the amount of fine-scale velocity and spatial structure diluted by the instrumental limitations of the presently available surveys; and the general problem of detailed mapping of the HI in the galaxy. Comparison is made between the distribution of HI and that of CO and several other galactic tracers. The galactic disk as defined by atomic hydrogen has a diameter fully twice as large as that defined by the ionized and molecular states of hydrogen, as well as by other molecules, supernova remnants, pulsars, gamma radiation, synchroton radiation, and the youngest stars. It is also less confined to the galactic equator than most of the other constituents. The degree of small-scale structure apparent in the molecular observations is much greater than in the HI observations. Parameters describing the small-scale structure were determined using Monte Carlo techniques to simulate the observations.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 177-205
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  • 63
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    Publication Date: 2006-01-12
    Description: The prospect that density waves and galactic shock waves are present on the large-scale in disk-shaped galaxies has received support in recent years from both theoretical and observational studies. Large-scale galactic shock waves in the interstellar gas are suggested to play an important, governing role in star formation, molecule formation, and the degree of development of spiral structure. Through the dynamics of the interstellar gas and the galactic shock wave phenomenon, a new insight into the physical basis underlying the morphological classification system of galaxies is suggested.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center The Struct. and Content of the Galaxy and Galactic Gamma Rays; p 128-162
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  • 64
    Publication Date: 2006-01-12
    Description: Different types of satellite and conventional remote sensing data are used to monitor urban growth and the pattern of development. Software programs were developed for a growth allocation model that uses LANDSAT information as the basic component.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 351-355
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  • 65
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    Publication Date: 2006-01-12
    Description: The earth resources remote sensing activity of Texas and its applications are reported. A combination of digital, photographic, and traditional methods is being used to manage the water impoundments inventory, a land use survey, a wildlife habitat survey, and a coastal zone survey.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 297-299
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  • 66
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    Publication Date: 2006-01-16
    Description: Three examples that illustrate the expected role of the Space Telescope in cosmological investigations are described addressing the distribution of globular star clusters, universe expansion, and other classical cosmological problems.
    Keywords: ASTROPHYSICS
    Type: NASA. Marshall Space Flight Center Sci. Res. with the Space Telescope; p 295-312
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  • 67
    Publication Date: 2006-01-16
    Description: Theories describing the central regions of nonthermal extragalactic sources (radio galaxies, Seyfert nuclei, quasars, etc.) are examined in the light of the experimental possibilities afforded by the Space Telescope. In particular, the theory which proposes the accretion of stars or gas onto a black hole as the explanation of the central engine is discussed. Planned observations directed towards the problem of the mass, size, and structure of the central engine, and the phenomenological questions regarding the general environment of the central engine are outlined.
    Keywords: ASTROPHYSICS
    Type: NASA. Marshall Space Flight Center Sci. Res. with the Space Telescope; p 197-214
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  • 68
    Publication Date: 2006-01-16
    Description: The stellar dynamics of globular clusters are addressed in terms of luminosity functions, chemical topics, and dynamical topics
    Keywords: ASTROPHYSICS
    Type: NASA. Marshall Space Flight Center Sci. Res. with the Space Telescope; p 139-150
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  • 69
    Publication Date: 2006-01-16
    Description: Jet Propulsion Laboratory Deep Space Station (DSS) location solutions based on two JPL planetary ephemerides, DE 84 and DE 96, at eight planetary encounters were used to obtain weighted least squares estimates of precession and polar motion errors. The solution for precession error in right ascension yields a value of 0.3 X 10 to the minus 5 power plus or minus 0.8 X 10 to the minus 6 power deg/year. This maps to a right ascension error of 1.3 X 10 to the minus 5 power plus or minus 0.4 X 10 to the minus 5 power deg at the first Voyager 1979 Jupiter encounter if the current JPL DSS location set is used. Solutions for precession and polar motion using station locations based on DE 84 agree well with the solution using station locations referenced to DE 96. The precession solution removes the apparent drift in station longitude and spin axis distance estimates, while the encounter polar motion solutions consistently decrease the scatter in station spin axis distance estimates.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The Deep Space Network; p 29-49
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  • 70
    Publication Date: 2006-01-12
    Description: The most important properties of the interplanetary medium are its interplanetary plasma (solar wind), magnetic field, galactic and solar cosmic rays, and micrometeorite material. Also considered is electromagnetic radiation from the sun, stars, and the galaxy.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington Found. of Space Biol. and Med., Vol. 1; p 32-111
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  • 71
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    Publication Date: 2006-01-12
    Description: Information is provided on how a potential user of remote sensing technology can gain access to all of the products and services he will need to get started. It was envisioned that these include data, training, hardware, and software. A very brief tutorial summary of the fundamentals of the technology is presented.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 367-370
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  • 72
    Publication Date: 2006-01-12
    Description: The origin of life on earth is seen arising as a natural consequence of a long series of physical and chemical processes taking place in association with evolution of the universe. The present theory is that any premordial earth atmosphere, resulting from accumulation from the primitive solar nebula, was probably swept away by the very intensive T Tauri stage of the solar wind. Subsequently, the present atmosphere and oceans of the earth were outgassed from the interior. Biochemical components of the gases were mainly water vapor and carbon dioxide.
    Keywords: ASTROPHYSICS
    Type: NASA, Washington Found. of Space Biol. and Med., Vol. 1; p 3-31
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  • 73
    Publication Date: 2006-01-12
    Description: The current land use map for the city of Los Angeles was developed by the guesstimation process and provides single stage information for each level in the critical geographical hierarchy for land use planning management. Processing and incorporation of LANDSAT data in the land use information system requires special funding; however, computergraphic maps are able to provide a viable information system for city planning and management.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-B; p 359-365
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  • 74
    Publication Date: 2006-04-06
    Description: In order to understand better the polygenetic evolution of landforms on the martian surface, field studies were conducted in and around the Kharga Depression, Egypt. The Kharga region, on the eastern edge of Egypt's Western Desert, was subject to erosion under mostly hyperarid climatic conditions, punctuated by brief pluvial episodes of lesser aridity, since early Pleistocene time. The region contains numerous landforms analogous to features on the martian surface: yardangs carved in layered surficial deposits and in bedrock, invasive dune trains, wind-modified channels and interfluves, and depressions bounded by steep scarps. Like many of the topographic depresions on Mars, the Kharga Depression was invaded by crescentic dunes. In Egypt, stratigraphic relations between dunes, yardangs, mass-wasting debris, and wind-eroded flash-flood deposits record shifts in the relative effectiveness of wind, water, and mass-wasting processes as a function of climate change.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Washington Rept. of Planetary Geology Program, 1983; p 225-227
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  • 75
    Publication Date: 2006-02-14
    Description: LANDSAT data acquired over an agricultural area along with ground enumeration of the same area are used to obtain crop acreage estimates which are better (as measured in terms of bias and variance) than can be obtained from either data source alone. Two basic approaches considered within the AgRISTARS program are a stratified crop acreage estimator and a regression estimator. A statement of the problem was mathematically formulated and some theorems were proved which relate to the variance of the two estimators. For a particular set of data, the regression and stratified estimators are compared in terms of certain easily computed parameters.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Houston Univ. The 1981 NASA ASEE Summer Fac. Fellowship Program, Vol. 2; 17 p
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  • 76
    Publication Date: 2006-04-06
    Description: Sand bars and islands within braided rivers have characteristic rhomboid or diamond shapes, often becoming very complex in form as the density of islands increases. Similar forms are observed in the martian outflow channels where the islands occur in groups. This contrasts with the more isolated martian islands which have airfoil shapes, as do isolated streamlined islands in rivers and in the Channeled Scabland. These observations indicate that the bar and island forms are controlled by the density of the islands, with increasing island interaction and flow modification as the density increases. As a continuation of previous flume experiments on the shapes of isolated islands, a new series of experiments investigate the modifications produced by a progressive increase in island density, finally leading to a true braided system.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Washington Rept. of Planetary Geol. Programs; p 198-199
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  • 77
    Publication Date: 2006-02-14
    Description: The objectives of this experiment are to collect and isotopically analyze interstellar gas atoms around the orbit of the Earth for the purpose of obtaining new data relevant to understanding nucleosynthesis, and to study the dynamics of the interstellar wind inside the heliosphere and the isotopic composition of the interstellar medium outside the heliosphere. The experiment hardware will act as a set of simple cameras with high-purity copper-beryllium collecting foils serving as the film. The experiment housing will mount and thermally control the foils, establish the viewing angles and viewing direction, provide baffling to reject ambient neutral particles, provide a voltage grid to reject ionospheric charged particles, sequence collecting foils, control exposure times, and protect the foils from contamination during the deployment and retrieval of the LDEF. After being returned to Earth, the entrapped atoms can be analyzed by mass spectroscopy to determine the relative abundance of the different isotopes of helium and neon. An attempt will also be made to detect argon.
    Keywords: ASTROPHYSICS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 98-100
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  • 78
    Publication Date: 2006-04-18
    Description: From observations of Vela X-1 with the MSSL 2.5-7.5 keV detector onboard Copernicus, the behavior of the source can be characterized by three phases: (1) high intensity, (2) low intensity, and (3) eclipse. Combining data from the 1972 Uhuru observations with eclipse observation yields a binary period of 8.963 + or - 0.001 days with zero phase on 1975 Feb. 6.97 + or - 0.04 UT. The low intensity phase is interpreted as being due to increased absorption in an accretion wake traveling across the line of sight (the spectral slope remains relatively constant throughout the cycle). Another period of enhanced absorption immediately after exit from eclipse may be due to a bow shock. Comparison of the two observations suggests that these structures vary from cycle to cycle and, since the orbital period is long, probably during each cycle.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 629-642
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  • 79
    Publication Date: 2006-04-18
    Description: The temporal behavior of three new events of modulated optical emission from Cyg X1, detected in July 1975, is presented. Short time periodicities in the optical band are investigated. Single photon pulses from the photomultiplier are recorded on magnetic tape together with a very accurate 1 kHz reference frequency. During playback of the tape, the reference signal gives a 1 ms timing to a scaler interfaced with a small processor and the number of photon per millisecond is recorded on a digital tape.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center X-ray Binaries; p 485-492
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  • 80
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    In:  CASI
    Publication Date: 2006-04-16
    Description: The history of remote sensing is reviewed and the scope and versatility of the several remote sensing systems already in orbit are discussed, especially those with sensors operating in other EM spectral modes. The multisensor approach is examined by interrelating LANDSAT observations with data from other satellite systems. The basic principles and practices underlying the use of thermal infrared and radar sensors are explored and the types of observations and interpretations emanating from the Nimbus, Heat Capacity Mapping Mission, and SEASAT programs are examined. Approved or proposed Earth resources oriented missions for the 1980's previewed include LANDSAT D, Stereosat, Gravsat, the French satellite SPOT-1, and multimission modular spacecraft launched from space shuttle. The pushbroom imager, the linear array pushbroom radiometer, the multispectral linear array, and the operational LANDSAT observing system, to be designed the LANDSAT-E series are also envisioned for this decade.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 327-387
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  • 81
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    In:  CASI
    Publication Date: 2006-04-16
    Description: The use of computer aided classification of LANDSAT data in developing water quality plans for New Jersey watersheds is used to exemplify how a state natural resource management program benefits from satellite imagery. The transition of a research and development system into an operational remote sensing system to help decision makers is demonstrated. Nontechnial issues that can assist (or hinder) an agency in adopting a new technology are examined. The progress of LANDSAT use by state government from the earliest stage of curiosity through to incorporation in actual state planning methods is charted. Potential applications of LANDSAT data to real information needs and solutions to management problems are examined. The problems and mistakes that occurred in using LANDSAT data in the past are discussed as well as the ways by which these problems were overcome.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 309-326
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  • 82
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    In:  CASI
    Publication Date: 2006-04-16
    Description: Information and activities are provided to: (1) enhance the ability to distinguish between a Geographic Information System (GIS) and a data management system; (2) develop understanding of spatial data handling by conventional methods versus the automated approach; (3) promote awareness of GIS design and capabilities; (4) foster understanding of the concepts and problems of data base development and management; (5) facilitate recognition of how a computerized GIS can model conditions in the present "real world" to project conditions in the future; and (6) appreciate the utility of integrating LANDSAT and other remotely sensed data into the GIS.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The LANDSAT Tutorial Workbook; p 277-308
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  • 83
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    In:  Other Sources
    Publication Date: 2011-08-19
    Description: Sample images obtained with the Shuttle Imaging Radar A (SIR-A) are presented, along with design and performance features of the SIR-A, Seasat and Landsat images of the same scenes for comparison purposes. The SIR-A functions at the L-band 25 cm at a frequency of 1278 GHz with a spectral bandwidth of 6 MHz. The images were taken at an angle of 47 deg and furnished a resolution of 40 m from an altitude of 259 km. The images covered a ground swath 50 km wide. The images are provided to assist in the development of effective techniques for interpreting radar imagery. The SIR-A instrument is a precursor of another imaging device which will be flown around Venus. The images provided include sections of France, Sardinia and Algeria.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Photo Interpretation (ISSN 0031-8523); 23; 4-17
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  • 84
    Publication Date: 2011-08-16
    Description: Stars in the range of 4 to 8 solar masses are known to develop degenerate carbon-oxygen cores of about 1.4 solar masses. Arguments are presented why, contrary to past assumption, carbon ignition may not lead to the formation of a detonation wave. Rather, an initially subsonic burning front results which subsequently may be brought under control by adiabatic expansion. This dynamic phase leads to a centrally incinerated and expanded core. The loosely bound red-giant envelope is ejected to form an extended nebula. Neutrino cooling of the core finally induces collapse. Provided that sufficient energy is liberated in the dynamic formation of a neutron star, a supernova event will result. The distended nebula is ideally suited for the production of the visible supernova light curves. Thus, carbon nondetonation may give a viable alternative evolution to supernovae that avoids the impasse encountered by the detonation-disrupted models.
    Keywords: ASTROPHYSICS
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  • 85
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    In:  Other Sources
    Publication Date: 2011-08-16
    Description: A model for the motion of flare-generated shocks through interplanetary streams is presented which illustrates the effects of a stream-shock interaction on the shock strength and geometry. It is a gasdynamic calculation based on Whitham's (1958) method and on an empirical approximation for the relevant characteristics of streams. The results show that the Mach number of a shock can decrease appreciably to near unity in the interaction region ahead of streams and that the interaction of a spherically symmetric shock with a spiral-shaped corotating stream can cause significant distortions of the initial shock-front geometry. The geometry of a shock discussed by Lepping and Chao (1972) is qualitatively explained by this model.
    Keywords: ASTROPHYSICS
    Type: Journal of Geophysical Research; 80; Oct. 1
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  • 86
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    In:  Other Sources
    Publication Date: 2011-08-16
    Description: It is shown that application of standard MHD arguments to hydromagnetic waves observed in the Crab Nebula dramatically improves the upper bound on photon rest mass. The standard argument that massive photons are governed by the Phoca field equations is outlined and applied to wisp features (identified as hydromagnetic waves) observed in the Crab. The results imply an upper limit for the photon rest mass of between 3 by 10 to the -54th power and 3 by 10 to the -53rd power gram, which is smaller than the best previous limits by a factor of 10,000 to 100,000. It is noted that although the present limit is probably valid in order of magnitude, some doubt remains since there are inconsistencies in the standard arguments.
    Keywords: ASTROPHYSICS
    Type: Physical Review Letters; 35; Oct. 27
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  • 87
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    Publication Date: 2011-08-16
    Description: Various aspects of the technology which are available to users now are described. Specific topics discussed include: data distribution: availability of and access to data; technology transfer: system use illustrations and availability of training; hardware systems descriptions: processing hardware constructed and available; data processing techniques: individual processing techniques; and future developments: a sampling of future technology.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-A; p 123-127
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  • 88
    Publication Date: 2011-08-16
    Description: Crop-weather models developed for wheat from an assembled base of approximately 45 years of climatic records and historic wheat yield and production data at the stratum level are described. Utilization of meteorological data acquired by the NOAA satellites is discussed.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-A; p 63-65
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  • 89
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    Publication Date: 2011-08-16
    Description: The remote sensing activities of the Department of Interior are summarized. The use of satellite imagery in land and water management is described. Specific topics discussed include: land use mapping, exploration and discovery of metal, oil, and gas deposits, location of geological faults, and repetitive monitoring of dynamic environmental phenomena related to water resources.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: NASA. Lyndon B. Johnson Space Center NASA Earth Resources Survey Symp., Vol. 2-A; p 33-36
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  • 90
    Publication Date: 2011-08-16
    Description: The lack of adequate institutional mechanisms to regulate, monitor and govern the use of commonly owned world resources appears to be politically destabilizing and subject to socioeconomic pressures of overpopulation, food shortages, cartelism, terrorism, and wealth distribution to developing countries. The capacity and propensity to wage war and its potential consequences are elaborated. It is shown that technology is one of the dominant factors affecting the exploration and management of commonly shared resources.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: The Future Environment; 29 p
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  • 91
    Publication Date: 2011-08-16
    Description: ERTS images were compared to surficial geologic maps, prepared through traditional field studies. Lithologic boundaries, bedrock outcrops, bedrock structures, and geomorphologic features were examined. An area southeast of the Twin Cities, located chiefly in northern Dakota County was studied, as well as the New Brighton 15-minute quadrangle located in portions of Ramsey and Anoka Counties. Visual comparison of geologic maps and ERTS imagery demonstrated the limitations of this approach to geological investigations. Bedrock outcrops and bedrock structure in the metropolitan area do not appear on ERTS imagery. However, certain glacial sediments can be identified and are potentially mappable. Certain geomorphological features were also discernable.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: Minn. Univ. A study of Minn. Forests and Lakes using Data from Earth Resources Technol. Satellites; 30 p
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  • 92
    Publication Date: 2011-08-16
    Description: The eigenvalue method to calculate models for periodically pulsating stars is used to study the stability of the resulting oscillations. This paper discusses results for a series of RR Lyrae models.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center Cepheids Modeling; p 129-135
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  • 93
    Publication Date: 2011-08-16
    Description: Numerical models of variable stars are established, using a nonlinear radiative transfer coupled hydrodynamics code. The variable Eddington method of radiative transfer is used. Comparisons are for models of W Virginis, beta Doradus, and eta Aquilae. From these models it appears that shocks are formed in the atmospheres of classical Cepheids as well as W Virginis stars. In classical Cepheids, with periods from 7 to 10 days, the bumps occurring in the light and velocity curves appear as the result of a compression wave that reflects from the star's center. At the head of the outward going compression wave, shocks form in the atmosphere. Comparisons between the hydrodynamic motions in W Virginis and classical Cepheids are made. The strong shocks in W Virginis do not penetrate into the interior as do the compression waves formed in classical Cepheids. The shocks formed in W Virginis stars cause emission lines, while in classical Cepheids the shocks are weaker.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center Cepheid Modeling; p 71-83
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  • 94
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    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Development of low lying southeastern shore of Pike Lake is described as part of the Rice Creek watershed study. Several small wetlands in Arden Hills, Minnesota were incorporated into the drainage plans as pollutant and nutrient sinks rather than being infilled. Lake water quality in the St. Paul-Minneapolis metropolitan area was analyzed using Landsat images. In the same urban area, the inventory and seasonal change of the open water were also studied.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: A Study of Minn. Forests and Lakes using Data from Earth Resources Technol. Satellites; 66 p
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  • 95
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    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Color observations of Cepheids can be interpreted by a color effective temperature relation to give different T sub e values for each kind of mean color. Here, theoretical colors from numerical integrations of Cepheid pulsations are used to determine the proper method of taking the color mean in order to get, by the color T sub e relation, the correct nonpulsating T sub e.
    Keywords: ASTROPHYSICS
    Type: NASA. Goddard Space Flight Center Cepheid Modeling; p 43-55
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  • 96
    Publication Date: 2011-08-16
    Description: The observed He II line spectrum in zeta Pup is compared with that predicted from model atmospheres in an attempt to establish the parameters (effective temperature, log g) which characterize the model that best represents this star's atmosphere. The study is conducted by compiling equivalent widths of the He II lines in the series (n = 2,3,4,5) and comparing them with predictions from plane-parallel static model atmospheres using a non-LTE theory of line formation. Good agreement between observation and prediction for a model atmosphere with an effective temperature of 50,000 K and log of 4.0 is found for the upper members of the n = 3 and n = 5 series, but discrepancies are found for the two lines of the n = 2 series and the upper members of the n = 4 series. It is shown that the n = 4 level appears to be more overpopulated at moderate atmospheric depths than the non-LTE calculations with plane-parallel layers indicate. It is suggested that this may be due to an overlap of the H and He II lines in the even-even series caused by macroturbulent velocities of the hydrogen and helium atoms.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 200; Sept. 15
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  • 97
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    Publication Date: 2011-08-16
    Description: Solar radiation pressure can cause rotational bursting and eventual elimination from the solar system of asymmetric dust particles by a windmill effect. The life span against this process for metallic particles with radii of 0.00001-0.01 cm ranges from 10 to 10,000 years. The effects of magnetic spin damping have been considered in this estimate. This depletion mechanism works faster than the traditional Poynting-Robertson effect by approximately one order of magnitude for metallic particles and about two-orders of magnitude for nonmetallic particles.
    Keywords: ASTROPHYSICS
    Type: Geophysical Research Letters; 2; Sept
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  • 98
    Publication Date: 2011-08-16
    Description: The heliocentric radial distribution of the flux of hyperbolic cosmic dust particles, as measured by the Pioneer 8 and 9 spacecraft, is closely related to the radial variation of the spatial density of source or parent meteoroids. Within the limits of the experimental and theoretical uncertainties the spatial density of parent meteoroids, as deduced from the hyperbolic cosmic dust data, is found to be increasing with increasing heliocentric distance in the neighborhood of one AU. Other recent experimental evidence confirms this result. The new results also suggest that the ratio of the areal density of submicron-sized craters to the areal density of millimeter-sized craters will be less on the north-south faces of lunar rocks than on the east-west faces of the same rocks. The change in ratio is not as large as previously thought. It is noted that the solar system is not presently contributing significant amounts of dust to the interstellar medium though it may once have done so.
    Keywords: ASTROPHYSICS
    Type: Planetary and Space Science; 23; Oct. 197
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  • 99
    Publication Date: 2011-08-16
    Description: The Second Small Astronomy Satellite (SAS-2) high-energy (in excess of 35 MeV) gamma-ray telescope has detected pulsed gamma-ray emission at the radio period from PSR 0833-45, the Vela pulsar, as well as an unpulsed flux from the Vela region. The pulsed emission consists of two peaks following the single radio peak by about 13 ms and 48 ms. The luminosity of the pulsed emission above 100 MeV from Vela is about 0.1 that of the pulsar NP 0532 in the Crab nebula, whereas the pulsed emission from Vela at optical wavelengths is less than 0.0002 that from the Crab. The relatively high intensity of the pulsed gamma-ray emission, and the double peak structure, compared with the single pulse in the radio emission, suggest that the high-energy gamma-ray pulsar emission may be produced under different conditions from those at lower energies.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 200; Sept. 1
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  • 100
    Publication Date: 2011-08-16
    Description: It is noted that the general intrinsic interpretation of QSO absorption redshifts predicts a high probability of clustering for the expulsion velocities of clouds ejected from a QSO core and that a correlation function has been defined which depends on the probability of clustering of three or more expulsion velocities. A test of this correlation is formulated which utilizes data on pairs of QSOs with similar emission redshifts and at least three well established absorption redshifts with corresponding expulsion velocities greater than 0.02c. It is shown that the correlation should be positive (maximum value +100%) if the absorption systems are intrinsic and correlated, zero if there is no physical connection among these systems, and negative if a strong anticorrelation exists or QSOs tend to eject one or two clouds at well separated characteristic velocities. Data on five QSOs are analyzed, and large positive values are obtained for the correlations.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 200; Sept. 1
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