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  • Weitere Quellen  (1.648)
  • NASA Technical Reports  (1.648)
  • EARTH RESOURCES AND REMOTE SENSING  (500)
  • AERODYNAMICS  (479)
  • METEOROLOGY AND CLIMATOLOGY  (353)
  • MECHANICAL ENGINEERING  (183)
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  • 1
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The joint airport weather studies (JAWS) project is discussed. The major objectives of the JAWS Project are a fundamental description of the phenomenon, a determination of the hazard potential and a definition of a protection and warning system, all of which are relative to low level wind shear. Aspects of the low level wind shear phenomenon. The principal focus, however, is the microburst. The microburst is fundamentally a rather simple atmospheric flow. It is a downdraft that, upon approaching the surface, spreads out horizontally, producing a diverging radial flow in all directions. For any direction that an aircraft flies through the microburst, it will first encounter increasing head winds; then the remnants of the downdraft; and then, increasing tail wind.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 85-95
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  • 2
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: A heavily instrumented F-106B aircraft was flown in thunderstorms to gather data for characterizing lightning at aircraft operating altitudes. Conventional weather finding techniques are supplemented with UHF lightning mapping radar to select the most active storm cells and the most likely altitude for obtaining direct lightning strikes to the airplane. One hundred seventy-six strikes were obtained in a 3 year period, mostly at an altitude of above 25,000 feet.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 63-65
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  • 3
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: A wind shear and vortex wake and their impact on aircraft were investigated. The systems and advice to help pilots, and rational scientific methods to assist in advising certification authorities and those interested in improving flight safety were developed. Wind Shear and Vortex Wakes are related, they are both invisible enemies of aircraft in the form of large disturbances in the atmosphere, both cause major accidents. Problems of building wakes at airports are is considered. Research on wind shear was initiated by the American FAA following the Boston, New York and Denver accidents to civil airliners. This resulted in: useful advice to pilots about wind shear; better attempts by the meteorologists at forecasting wind shear conditions; and useful ideas for wind shear measurement and warning systems. Three major research tasks are outstanding: (1) Worldwide measurements to give reliable estimates of probability and details of the forms of large wind shears; (2) Developments of real time wind shear measuring systems for ground or airborne use; and (3) Establishing relationships between measured wind shear and the potential hazard to an aircraft, or class of aircraft.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 66-83
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  • 4
    Publikationsdatum: 2006-02-14
    Beschreibung: Marked surface inversions occur most frequently in dry continental climates, where low atmospheric humidity allows heat transfer by long wave thermal radiation. In the northern latitudes, surface inversions reach their maximum intensity during the winter, when the incoming Sun's radiation is negligible and radiative cooling is dominant during the long nights. During winter, air mass boundaries are sharp, which causes formation of marked surface inversions. The existence of these inversions and sharp boundaries increase the risk of wind shear. The information should refer to marked inversions exceeding a temperature difference of 10 deg C up to 1000 feet. The need to determine the temperature range over which he information is operationally needed and the magnitude of the inversion required before a notification to pilots prior to departure is warranted are outlined.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 61-62
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  • 5
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The Gust Gradient Program is a data intensive effort involving tripple Doppler radar, a surface weather station mesonet and other aircraft. The Joint Airport Weather Studies was utilized to gain additional data. The data were used to fill in the gap in turbulence modeling.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 38-42
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  • 6
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The objective of the Generalized Exponential Markov (GEM) Program was to develop a weather forecast guidance system that would: predict between 0 to 6 hours all elements in the airways observations; respond instantly to the latest observed conditions of the surface weather; process these observations at local sites on minicomputing equipment; exceed the accuracy of current persistence predictions at the shortest prediction of one hour and beyond; exceed the accuracy of current forecast model output statistics inside eight hours; and be capable of making predictions at one location for all locations where weather information is available.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 42-44
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  • 7
    Publikationsdatum: 2006-02-14
    Beschreibung: Recommendations based on need, cost, and achievement of flight safety are offered, and the re-evaluation of weather parameters needed for safe landing operations that lead to reliable and consistent automated observation capabilities are considered.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 19-20
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  • 8
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    In:  CASI
    Publikationsdatum: 2006-02-14
    Beschreibung: The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 14-16
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  • 9
    Publikationsdatum: 2006-02-14
    Beschreibung: The implementation of the National Airspace System (NAS) will improve safety services to aviation. These services include collision avoidance, improved landing systems and better weather data acquisition and dissemination. The program to improve the quality of weather information includes the following: Radar Remote Weather Display System; Flight Service Automation System; Automatic Weather Observation System; Center Weather Processor, and Next Generation Weather Radar Development.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Marshall Space Flight Center Proc.: 6th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 21-25
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  • 10
    Publikationsdatum: 2011-08-19
    Schlagwort(e): AERODYNAMICS
    Materialart: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 607-63
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  • 11
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    In:  Other Sources
    Publikationsdatum: 2011-08-19
    Schlagwort(e): AERODYNAMICS
    Materialart: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 557-58
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  • 12
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    Publikationsdatum: 2011-08-19
    Schlagwort(e): AERODYNAMICS
    Materialart: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 539-55
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  • 13
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    In:  Other Sources
    Publikationsdatum: 2011-08-19
    Schlagwort(e): AERODYNAMICS
    Materialart: NASA. Langley Research Center, Theoretical Aerodynamics Contractors' Workshop, Volume 2; p 461-49
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  • 14
    Publikationsdatum: 2011-08-18
    Beschreibung: A multistage sampling procedure using image processing, geographical information systems, and analytical photogrammetry is presented which can be used to guide the collection of representative, high-resolution spectra and discrete reflectance targets for future satellite sensors. The procedure is general and can be adapted to characterize areas as small as minor watersheds and as large as multistate regions. Beginning with a user-determined study area, successive reductions in size and spectral variation are performed using image analysis techniques on data from the Multispectral Scanner, orbital and simulated Thematic Mapper, low altitude photography synchronized with the simulator, and associated digital data. An integrated image-based geographical information system supports processing requirements.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 15
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: Transmission of power in space using lasers will require devices for converting the laser power to electrical power. One such type of device for accomplishing this is the photovoltaic converter. This paper reviews photovoltaic converters and their application for conversion of monochromatic laser power to electrical power. Laser power densities greater than 1000 W/sq cm are considered. For a converter operated at 300 K a lower bandgap limit of 0.67 eV (1.80 micron) is defined. For ideal conditions, an efficiency of 47.8 percent is calculated for Nd/Liquid laser radiation incident on an Si converter. Several types of photovoltaic converters are discussed. Series resistance is identified as a major problem. Vertical multijunction converters are the most promising photovoltaic devices for use as laser to electric power converters.
    Schlagwort(e): SPACECRAFT PROPULSION AND POWER
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  • 16
    Publikationsdatum: 2011-08-18
    Beschreibung: A solar power plant suitable for earth orbits passing through Van Allen radiation belts is described. The solar-to-electricity conversion efficiency is estimated to be around 9 percent, and the expected power-to-weight ratio is competitive with photovoltaic arrays. The system is designed to be self-contained, to be indifferent to radiation belt exposures, store energy for periods when the orbiting system is in earth shadow (so that power generation is contant), have no moving parts and no working fluids, and be robust against micrometeorite attack. No electrical batteries are required.
    Schlagwort(e): SPACECRAFT PROPULSION AND POWER
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  • 17
    Publikationsdatum: 2011-08-18
    Beschreibung: Many future satellites and spacecraft with spun and despun configurations will require the transfer of power across rotating interfaces in lieu of slip-rings and/or flexures. This is particularly true of spacecraft that have to demonstrate a long life expectancy. The rotary transformer has the desirable characteristics of high reliability and low noise, which qualify it as a potential replacement for slip rings. Development of a rotary power transformer follows the successful completion of a task to develop rotary signal-level transformers for the Galileo Spacecraft Project. The physical configuration of a rotary power transformer has a significant effect on its magnetic and electrical characteristics and therefore impacts the design of the dc/ac inverter driver. Important characteristics addressed during this development effort include: operating frequency, efficiency, transformer gap size, leakage inductance, and leakage flux. A breadboard inverter and rotary transformer were designed, fabricated and tested.
    Schlagwort(e): SPACECRAFT PROPULSION AND POWER
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  • 18
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: Two-phase turbines would be useful in Rankine cycles using low-quality or saturated-liquid working fluids. The chief problem is low efficiency due to slip losses in nozzles and due to liquid impact and friction losses in rotors. To raise efficiency, a staging method was tested in which the first stage operated at high speed with low relative liquid velocity, and the second stage recovered the first-stage exit energy. The theoretical efficiency for an experimental turbine operating with Refrigerant-22 was raised from 55 percent to 66 percent, and the measured efficiency was raised from 52 percent to 57 percent.
    Schlagwort(e): MECHANICAL ENGINEERING
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  • 19
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    Publikationsdatum: 2011-08-18
    Beschreibung: An overview of the DOE/NASA Automotive Stirling Engine Project is presented. The background and objectives of the project are reviewed. Project activities are described and technical progress and status are presented and assessed. Prospects for achieving the objective 30 percent fuel economy improvement are considered good. The key remaining technology issues are primarily related to life, reliability and cost, such as piston rod seals, and low cost heat exchanges. Previously announced in STAR as N83-27924
    Schlagwort(e): MECHANICAL ENGINEERING
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  • 20
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    Publikationsdatum: 2011-08-18
    Beschreibung: A goal of future synthetic aperture radar (SAR) system design is to yield the radiometrically accurate imagery necessary for use in classification problems. To accomplish this, a reliable calibration technique must be developed. Many such techniques have been proposed (e.g., Stiles and Holtzman, 1982); however, until now, none have been tested on spaceborne SAR digital data. In this paper, a method of significantly increasing the reproducibility of several independent Seasat SAR data sets of a test site using an automated correction procedure is described.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 21
    Publikationsdatum: 2011-08-18
    Beschreibung: A series of experiments have been conducted to examine the sensitivity of forecast skill to various data and data analysis techniques for the 0000 GMT case of January 21, 1979. These include the individual components of the FGGE observing system, the temperatures obtained with different satellite retrieval methods, and the method of vertical interpolation between the mandatory pressure analysis levels and the model sigma levels. It is found that NESS TIROS-N infrared retrievals seriously degrade a rawinsonde-only analysis over land, resulting in a poorer forecast over North America. Less degradation in the 72-hr forecast skill at sea level and some improvement at 500 mb is noted, relative to the control with TIROS-N retrievals produced with a physical inversion method which utilizes a 6-hr forecast first guess. NESS VTPR oceanic retrievals lead to an improved forecast over North America when added to the control.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 22
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    Publikationsdatum: 2011-08-18
    Beschreibung: An assessment is made of the extent to which polar filtering may seriously affect the skill of latitude-longitude NWP models, such as the U.S. Navy's NOGAPS, or the GLAS fourth-order model. The limited experiments which have been completed to date with the 4 x 5-deg, 9-level version of the latter model indicate that the high latitude filter currently in operation affects its forecasting skill very little, with only one exception in which the use of the PG filter significantly improved forecasting.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 23
    Publikationsdatum: 2011-08-18
    Beschreibung: The present investigation has as objective to take a detailed look at the intense squall line over Oklahoma on May 2-3, 1979, using GOES stereoscopy combined with GOES infrared data. The synoptic situation and data sources are considered along with the stereoscopically observed cloud top ascent rates. Cloud top observations of intense thunderstorms are discussed, taking into account a contouring technique, the interpretation of infrared cloud top temperature patterns, and small-scale structure and its variability. It is found that GOES IR cloud top temperatures grossly underestimate the actual cloud top height observed stereoscopically, especially for immature storms. It is difficult to define growing storms below about 10 km in the GOES infrared data.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Monthly Weather Review (ISSN 0027-0644); 111; 1949-196
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  • 24
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    Publikationsdatum: 2011-08-19
    Beschreibung: The transport mechanisms responsible for the seasonal behavior of total ozone are deduced from the comparison of model results to stratospheric data. The seasonal transport is dominated by a combination of the diabatic circulation and transient planetary wave activity acting on a diffusively and photochemically determined background state. The seasonal variation is not correctly modeled as a diffusive process. The buildup of total ozone at high latitudes during winter is dependent upon transient planetary wave activity of sufficient strength to cause the breakdown of the polar vortex. While midwinter warmings are responsible for enhanced ozone transport to high latitudes, the final warming marking the transition from zonal mean westerlies to zonal mean easterlies is the most important event leading to the spring maximum. The final warming is not followed by reacceleration of the mean flow; so that the ozone transport associated with this event is more pronounced than that associated with midwinter warmings.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Pure and Applied Geophysics (ISSN 0033-4553); 121; 5-6,
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  • 25
    Publikationsdatum: 2011-08-19
    Beschreibung: The evolution of wave energy, enstrophy, and wave motion for atmospheric Rossby waves in a variable mean flow are discussed from a theoretical and pedagogic standpoint. In the absence of mean flow gradients, the wave energy density satisfies a local conservation law, with the appropriate flow velocity being the group velocity. In the presence of mean flow variations, wave energy is not conserved, but wave action is, provided the mean flow is independent of longitude. Wave enstrophy is conserved for arbitrary variations of the mean flow. Connections with Eiiassen-Palm flux are also discussed.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Pure and Applied Geophysics (ISSN 0033-4553); 121; 5-6,; 917-946
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  • 26
    Publikationsdatum: 2011-08-18
    Beschreibung: A technique for quantifying the absorption that takes place in the 15 micron CO2 band in the atmosphere is developed as a function of the scaled CO2 content. A spectrally averaged transmission function is defined and a scaling approximation for the absorption coefficient is calculated, as is the width of the absorption band. An assessment is made of the accuracies of the parameterized atmospheric transmittance and cooling rate. The resulting radiation parameterization is applied in a climate sensitivity study. The model is concluded useful in examining atmospheres with a variable CO2 content, with the highest accuracies being available in the troposphere and the lower stratosphere. CO2 doubling the earth's atmosphere is projected to cause a 20 percent warming in the surface temperatures and a 30 percent warming for the tripling of the CO2 content, provided the spectral range for CO2 absorption is extended from 580-760 to 540-800/cm.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Journal of the Atmospheric Sciences (ISSN 0022-4928); 40; 2183-219
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  • 27
    Publikationsdatum: 2011-08-18
    Beschreibung: The Indian summer monsoon rainfall and the Darwin pressure anomalies are examined for the 81-year period 1901-81. It is found that the tendency of the Darwin pressure anomaly before the monsoon season is a good indicator of the monsoon rainfall anomaly. During the 81-year period, there were only two instances (1901, 1941) when a negative tendency of winter (December, January, February) to spring (March, April, May) Darwin pressure anomaly was followed by a monsoon rainfall anomaly of less than minus one standard deviation; and only three instances (1916, 1933, 1961) when a positive tendency was followed by a rainfall anomaly of more than one standard deviation. Therefore, if the Darwin pressure anomaly during March, April and May is below normal, and if the Darwin seasonal pressure anomaly has been falling, a non-occurrence of drought over India can be predicted with a very high degree of confidence. Similarly, above normal Darwin pressure during March, April and May, and increasing seasonal pressure anomaly is a good indicator of the non-occurrence of very heavy rain over India.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Monthly Weather Review (ISSN 0027-0644); 111; 1830-183
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  • 28
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    Publikationsdatum: 2011-08-18
    Beschreibung: The potential of planform modification and hinge-line relocation to improve the thrust efficiency of vortex flaps was experimentally investigated on a 60-deg cropped delta wing model. Spanwise segmentation of the flap, together with chord-tailoring of the segments, allowed the vortex to be maintained on the outboard flap surfaces to higher angles of attack. In addition, location of the flap hinge aft of and underneath the wing leading edge generated substantial thrust from the vortex suction acting on the leading-edge lower surface. A combination of these beneficial effects allowed the flap/wing area to be reduced from 11.4 percent of the continuous flap to 6.3 percent of segmented flap, essentially without detriment to the incremental lift-to-drag ratio due to flap addition in the lift coefficient range 0.5-0.7 based on the basic wing area.
    Schlagwort(e): AERODYNAMICS
    Materialart: Journal of Aircraft (ISSN 0021-8669); 20; 1062-106
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  • 29
    Publikationsdatum: 2011-08-18
    Beschreibung: Previously cited in issue 20, p. 3138, Accession no. A82-40893
    Schlagwort(e): AERODYNAMICS
    Materialart: Journal of Aircraft (ISSN 0021-8669); 20; 993-1006
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  • 30
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    Publikationsdatum: 2011-08-18
    Beschreibung: Previously cited in issue 06, p. 799, Accession no. A82-17876
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 21; 1611-161
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  • 31
    Publikationsdatum: 2011-08-18
    Beschreibung: In this paper, some of the effects of unbalance on the nonlinear response and stability of flexible rotor-bearing systems is presented from both a theoretical and experimental standpoint. In a linear system, operating above its stability threshold, the amplitude of motion grows exponentially with time and the orbits become unbounded. In an actual system, this is not necessarily the case. The actual amplitudes of motion may be bounded due to various nonlinear effects in the system. These nonlinear effects cause limit cycles of motion. Nonlinear effects are inherent in fluid film bearings and seals. Other contributors to nonlinear effects are shafts, couplings and foundations. In addition to affecting the threshold of stability, the nonlinear effects can cause jump phenomena to occur at not only the critical speeds, but also at stability onset or restabilization speeds.
    Schlagwort(e): MECHANICAL ENGINEERING
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  • 32
    Publikationsdatum: 2011-08-18
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 33
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    Publikationsdatum: 2011-08-18
    Beschreibung: The improved spatial resolution of the new earth resources satellites will increase the need for effective utilization of spatial information in machine processing of remotely sensed data. One promising technique is scene segmentation by region growing. Region growing can use spatial information in two ways: only spatially adjacent regions merge together, and merging criteria can be based on region-wide spatial features. A simple region growing approach is described in which the similarity criterion is based on region mean and variance (a simple spatial feature). An effective way to implement region growing for remote sensing is as an iterative parallel process on a large parallel processor. A straightforward parallel pixel-based implementation of the algorithm is explored and its efficiency is compared with sequential pixel-based, sequential region-based, and parallel region-based implementations. Experimental results from on aircraft scanner data set are presented, as is a discussioon of proposed improvements to the segmentation algorithm.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 34
    Publikationsdatum: 2011-08-18
    Beschreibung: Approaches for developing an improved passive microwave technique to delineate rain from wet land surfaces are considered, and an investigation is conducted with the objective to study the application of these ideas with empirical data. The investigation includes a statistical analysis of Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) 37.0, 18.0, and 10.7 GHz data. The possibility was assessed to make use of the 18.0 and 10.7 GHz channels in order to reduce the ambiguities found in the 37.0 GHz radiometer data for differentiating rainfall areas from wet land surfaces. It was found, however, that none of the SMMR channels could differentiate rain from wet or dry land when surface temperatures were less than 15 C. It appears that an improved rainfall-over-land detection technique could be developed by two different methods, utilizing both satellite infrared and multifrequency dual polarized passive microwave data.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Journal of Climate and Applied Meteorology (ISSN 0733-3021); 22; 1753-176
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  • 35
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    Publikationsdatum: 2011-08-18
    Beschreibung: In order to utilize satellite measurements of optical thickness over land for estimating aerosol properties during air pollution episodes, the optical thickness was measured from the surface and investigated. Aerosol optical thicknesses have been derived from solar transmission measurements in eight spectral bands within the band lambda 440-870 nm during the summers of 1980 and 1981 near Washington, DC. The optical thicknesses for the eight bands are strongly correlated. It was found that first eigenvalue of the covariance matrix of all observations accounts for 99 percent of the trace of the matrix. Since the measured aerosol optical thickness was closely proportional to the wavelength raised to a power, the aerosol size distribution derived from it is proportional to the diameter (d) raised to a power for the range of diameters between 0.1 to 1.0 micron. This power is insensitive to the total optical thickness. Changes in the aerosol optical thickness depend on several aerosol parameters, but it is difficult to identify the dominant one. The effects of relative humidity and accumulation mode concentration on the optical thickness are analyzed theoretically, and compared with the measurements.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Journal of Climate and Applied Meteorology (ISSN 0733-3021); 22; 1694-170
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  • 36
    Publikationsdatum: 2011-08-18
    Beschreibung: The scientific instruments comprising the OSTA-1 package flown on the second Shuttle mission (November 12-14, 1981) are listed, and the Shuttle Imaging Radar (SIR-A) experiments are examined in detail: SIR-A operated for 8 h and obtained images covering more than 10 million sq km at 40-m resolution. The images were recorded on photographic film and processed in holographic form at JPL, and data for Southern Europe and parts of Africa were distributed to French scientists by the Groupement pour le Developpement de la Teledetection Aerospatiale. The main areas of research were environmental studies and geology, and the SIR-A images were used in combination with aerial photography, thematic maps, and Landsat images. The technical specifications of the SIR-B radar planned for STS-17 in 1984 are compared with those of SIR-A and Seasat SAR in tables.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Societe Francaise de Photogrammetrie et de Teledetection, Bulletin (ISSN 0244-6014); 91, 1; 5-9
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  • 37
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    Publikationsdatum: 2011-08-18
    Beschreibung: The use of remote sensing in resource exploration is reviewed, with emphasis placed on new developments in high spectral resolution remote-sensing techniques for mineralogic and vegetation mapping. Topics discussed include aerial photography and satellite remote sensing, concepts and principles of spectral data collection, spectral properties of rocks and minerals, spectral properties of vegetation, and botanical aspects of geochemical stress. The discussion also covers applications of Landsat multispectral scanner data to lithologic and geobotanic studies and the future development of data acquisition and data interpretation techniques.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: Economic Geology and Society of Economic Geologists, Bulletin (ISSN 0361-0128); 78; 573-590
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  • 38
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    Publikationsdatum: 2011-08-18
    Beschreibung: The paper addresses the potential that ceramic materials can play an important role in future automotive powerplants - both advanced heat engines and advanced battery systems. A number of related experimental programs are reviewed including ceramics for gasoline and diesel piston engines, gas turbine and Stirling Engines and sodium-sulfur batteries. A strong integrated program to develop ceramics technology is recommended.
    Schlagwort(e): MECHANICAL ENGINEERING
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  • 39
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    Publikationsdatum: 2011-08-18
    Beschreibung: A mesh system composed of multiple overset body-conforming grids is described for adapting finite-difference procedures to complex aircraft configurations. In this so-called 'chimera mesh,' a major grid is generated about a main component of the configuration and overset minor grids are used to resolve all other features. Methods for connecting overset multiple grids and modifications of flow-simulation algorithms are discussed. Computational tests in two dimensions indicate that the use of multiple overset grids can simplify the task of grid generation without an adverse effect on flow-field algorithms and computer code complexity.
    Schlagwort(e): AERODYNAMICS
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  • 40
    Publikationsdatum: 2011-08-18
    Beschreibung: In this paper, results of a Monte Carlo simulation of the effect of noise on the relationship between the microwave emissivity of soil and its moisture content are presented. It is found that whenever the magnitude of the noise for the independent variable, in this case the soil moisture, is increased, both the slope of the regression and the correlation coefficient decrease. In particular, when the noise has magnitude equivalent to a coefficient of variation of 0.25, the slope and correlation coefficient are in good agreement with those obtained from the data of a 21-cm airborne microwave radiometer which was flown over a test site in hand county, South Dakota. The comparison was made using a linear relationship to determine the estimated emissivity from the ground measurements of soil moisture. The linear relationship was derived from a radiative transfer model calculation of the microwave emissivities using realistic soil-moisture profiles. The effect of surface roughness was included in the relationship, and the variability of the surface roughness was also simulated by a Monte Carlo technique.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-21; 473-479
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  • 41
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    Publikationsdatum: 2011-08-18
    Beschreibung: The development of a preprocessing unit for Landsat Thematic Mapper (TM) data for the Earth Observations Data Laboratory at Johnson Space Center is reported. The background of the project is sketched, including the greatly increased data-handling requirements compared to MSS, the influence of the JPL VICAR system on the system design, and the completeness of the GSFC SCROUNGE (LASLIB) TM data tapes. The design approach and realization are discussed, and the performance and transportability of the preprocessor programs (totaling about 2000 lines of source code in FORTRAN and IBM Assembly languages) are indicated. The system is able to read the TM image tapes, extract areas of interest to particular studies, and register the extracted imagery to suitable references. Ancillary programs include image enhancement, rotation, filtering and pixel-size modification.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 42
    Publikationsdatum: 2011-08-18
    Beschreibung: Features of the NASA Regional Application Program for providing state and local land management agencies an opportunity to assess the usefulness of emerging remote sensing technology are described. The Program guidelines necessitated configuring software for local facilities, assuring that the aggncy involved furnished manpower, and applying the technology to local needs. The study focused on the southwestern U.S., particularly for purposes of water management, federal/state ownership/policy, energy development, environmental impact issues, timber and range inventory, fire control, and urban expansion. Demonstration projects were conducted in various topics, according to the state surveyed, with the success of the projects determined by the willingness of the agencies to continue with the technology, which happened in several cases.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
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  • 43
    Publikationsdatum: 2011-08-18
    Beschreibung: Previously cited in issue 15, p. 2361, Accession no. A82-31876
    Schlagwort(e): SPACECRAFT PROPULSION AND POWER
    Materialart: Journal of Energy (ISSN 0146-0412); 7; 442-448
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  • 44
    Publikationsdatum: 2011-08-18
    Beschreibung: Previously cited in issue 17, p. 2873, Accession no. A81-38082
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 21; 1492-149
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  • 45
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    Publikationsdatum: 2011-08-18
    Beschreibung: The analysis of the blizzard, an intense cyclone that was accompanied by unusually heavy snowfall, high winds, and cold temperatures, is carried out using a collection of detailed surface weather observations. It follows the cyclone from its genesis along a slow-moving frontal system through its rapid development and occlusion along the Middle Atlantic and southern New England coasts. Unusual aspects of the cyclone are discussed. Among these are the limited areal extent of heavy snow accumulations, the establishment of very cold air across western New England and the Middle Atlantic states, a persistent stationary front zone across central New England that separated frigid continental air from maritime air, and the slow movement and rapid warming associated with the decay of the storm.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: American Meteorological Society, Bulletin (ISSN 0003-0007); 64; 1258-127
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  • 46
    Publikationsdatum: 2011-08-18
    Beschreibung: Measurements for Washington, DC and Boulder, CO are combined to provide a time series of midlatitude stratospheric water vapor data for the period 1964-82. The mean concentration for the data period is shown to be nearly constant with altitude for the low stratospheric layer between 16-22 km with a mass mixing ratio for the layer of 2.5-2.6 ppmm. Above 22 km the mixing ratio increases slightly with altitude. Evident in the 60 mb level time series is an annual cycle, a quasi-biennial cycle and a long-term nonlinear trend. The quasi-biennial cycle in water vapor at midlatitudes is consistent with variations in tropical stratosphere zonal winds and temperature and total ozone and suggests a modulation of the Hadley cell circulation. The long-term trend shows mixing ratio increasing during the 1960s and decreasing in the 1970s after 1972.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Journal of the Atmospheric Sciences (ISSN 0022-4928); 40; 2157-216
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  • 47
    Publikationsdatum: 2011-08-18
    Beschreibung: The techniques used to obtain the mean equivalent temperature of the eye wall for Hurricanes Frederic (1979) and Allen (1980) using GOES satellite IR and stereoscopic observations are described. The eye wall is the area of greatest convection near the center of the storm, and is bounded by the inner radius around the eye and the outer radius bounding the area of inner core convection. The stereoscopic capability afforded by the GOES West and East spacecraft permits simultaneous, two-view imagery of a tropical cyclone, yielding height measurement accuracies of 0.5 km and horizontal accuracies as small as 1 km. An airborne lidar unit was used to verify the height measurements made of Hurricane Frederic. At the same time, the GOES East Visible IR Spin Scan Radiometer (VISSR) provided the mean wall temperatures from the release of latent heat. The trials aided in identifying the assumptions and consequent inaccuracies introduced into the temperature sounding data during analysis. The satellite data is concluded useful for monitoring changes in storm intensity.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: Monthly Weather Review (ISSN 0027-0644); 111; 1599-161
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  • 48
    Publikationsdatum: 2011-08-19
    Beschreibung: An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: ASME; 713-718
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  • 49
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    Publikationsdatum: 2011-08-18
    Beschreibung: The status of a fluorine/hydrazine thruster development program is discussed. A solid rhenium metal sea-level thrust chamber was successfully fabricated and tested for a total run duration of 1075 s with 17 starts. Rhenium fabrication methods are discussed. A test program was conducted to evaluate performance and chamber cooling. Acceptable performance was reached and cooling was adequate. A flight-type injector was fabricated that achieved an average extrapolated performance value of 3608 N-s/kg (368 lbf-s/lbm). Altitude thrust chambers were fabricated. One chamber incorporates a rhenium combustor and nozzle with an area ratio of 15:1, and a columbium nozzle extension with area ratios from 15:1 to 60:1. The other chamber was fabricated completely with a carbon/carbon composite. Because of the attributes of rhenium for use in high-temperature applications, a program to provide the materials and processes technology needed to reliably fabricate and/or repair vapor-deposited rhenium parts of relatively large size and complex shape is recommended.
    Schlagwort(e): SPACECRAFT PROPULSION AND POWER
    Materialart: APL The 1983 JANNAF Propulsion Meeting, Vol. 1; p 85-90
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  • 50
    Publikationsdatum: 2011-08-18
    Beschreibung: Monitoring biomass of wetlands ecosystems can provide information on net primary production and on the chemical and physical status of wetland soils relative to anaerobic microbial transformation of key elements. Multispectral remote sensing techniques successfully estimated macrophytic biomass in wetlands systems. Regression models developed from ground spectral data for predicting Spartina alterniflora biomass over an entire growing season include seasonal variations in biomass density and illumination intensity. An independent set of biomass and spectral data were collected and the standing crop biomass and net primary productivity were estimated. The improved spatial, radiometric and spectral resolution of th LANDSAT-4 Thematic Mapper over the LANDSAT MSS can greatly enhance multispectral techniques for estimating wetlands biomass over large areas. These techniques can provide the biomass data necessary for global ecology studies.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Goddard Space Flight Center LANDSAT-4 Sci. Characterization; 4 p
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  • 51
    Publikationsdatum: 2011-08-18
    Beschreibung: Thematic mapper scenes for Washington, D.C. and Macon, Georgia were examined to determine their radiometry and geometric accuracy. Specific band ratios were used to determine their effectiveness in defining vegetation and rock mineralogy. the TM 3/4 band ratio was used to define vegetation and the 5/2 band ratio was used to define limonitic rocks. The 5/7 band ratio was evaluated to test the effectiveness of the 1.6 and 2.2 mm bands in detecting clay and carbonate bearing rocks. Preliminary results show that clay minerals containing absorption bands at 2.2 mm, which are centered in the TM band 7, can be readily detected when the band ratio images are suitably contrast stretched. Bright rocks, such as marbles, which contain absorption bands in the 2.33 mm region, near the wavelength of TM band 7, are only evident upon harsher contrast stretching of the 5/7 band ratio. Geobotanical studies of Washington, D.C. show that monospecific forest canopies can be differentiated.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Goddard Space Flight Center LANDSAT-4 Sci. Characterization; 5 p
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  • 52
    Publikationsdatum: 2011-08-18
    Beschreibung: There are small differences between the average DN for the 16 detectors in each band, typically 0.8 DN; the standard deviations also differ typically by 0.4 DN. Differences of mode in a band are as large as 6 DN. Some DN levels appear to be strongly favored over adjacent levels. Differences between forward and reverse scans are approximately 0.1 DN in the mean, and 0 to 0.6 DN in the standard deviation. Geometrically resampled images (P data), in which the fixed correspondence between lines and single detectors is lost, are statistically similiar to the ensemble of detectors in each band in A data. The magnitude of inter-detector variation is readily seen by making an image of the first derivative in the vertical (line) direction of a flat field and stretching progressively wider ranges to gray; most detectors differ from their neighbors by 1 to 2 DN. The film output from the GSFC filmwriter used for TM images was found to have scale errors in both sample and line directions corresponding to four pixels in a TM image, and skew corresponding to three pixels.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Goddard Space Flight Center LANDSAT-4 Sci. Characterization; 2 p
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  • 53
    Publikationsdatum: 2011-08-18
    Beschreibung: An approach is described for providing periodic inflight absolute radiometric calibrations of the LANDSAT-4 sensors by reference to selected, instrumented ground areas. Results of some early ground measurements and computer simulations are presented. Selection of a suitable ground reference site, accurate measurement of the spectral reflectance of the selected area, determination of atmospheric characteristics during the morning of the sensor overpass, reduction of the measured data and their use in an appropriate atmospheric radiative transfer program, and comparison of the radiance level data with the digital counts of for the images of the selected areas are discussed. Preliminary measurements of gypsum are being made as an aid in defining the characteristics of field equipment to be constructed and calibrated for use over the White Sands Missile Range.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Goddard Space Flight Center LANDSAT-4 Sci. Characterization; 3 p
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  • 54
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    Publikationsdatum: 2011-08-18
    Beschreibung: Data collected on the spectral characteristics of the LANDSAT-4 and LANDSAT-4 backup thematic mapper instruments, the protoflight (PF) and flight (F) models, respectively are analyzed and summarized. Tests were conducted on the instruments and their components to determine compliance with two sets of spectral specifications: Band-by-band spectral coverage and channel-by-channel within-band spectral matching.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: LANDSAT-4 Sci. Characterization; 2 p
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  • 55
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    Publikationsdatum: 2011-08-18
    Beschreibung: The TM band 6 shutter background and the 34.7 C internal black body signal were measured over 50 day dates. Variability of the shutter background temperature was from 7 C to 11 C. For ten specific images, the digital counts of the calibration data were measured. The average pulse value of the black body peak decreased from 174 to 149 counts while the shutter background counts varied as a function of shutter temperature from 77 to 85. Relative internal gains between the four channels were calculated and compared to prelaunch values. They showed gains over 9 months of up to 5%. Frequency histograms of number of pixels vs. digital counts from a night scene were used to determine gain relative to the mean and to discern a systematic along-scan pattern in a difference between forward and reverse scan counts of up to 0.5. A corrected digital image was obtained. A temperature estimate for and area of Lake Erie of 18.5 C to 19.9 C was obtained. Local temperature records showed 21 C.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: LANDSAT-4 Sci. Characterization; 3 p
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  • 56
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    Publikationsdatum: 2011-08-18
    Beschreibung: Differences in overall sensor response, due to both factors within the sensor system, and external factors such as atmospheric effects, must be dealt with before change detection techniques using image differencing can be successfully implemented. The approach used to be coregister data to a base, followed by between image scatterogram generation and evaluation, and image differencing. Data from LANDSAT 2 and 3 were registered to LANDSAT 4 data. The area was limited to a small protion of the scene near the City of Santa Cruz because this was the only area cloud and haze free on all the images. Visual examination of each image, as well as the between image scatterograms, provide information on radiometric characteristics of each sensor. The image differencing, after normalizing for radiometric differences, provides a visual depiction of geometric distortions.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Goddard Space Flight Center LANDSAT-4 Sci. Characterization; 2 p
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  • 57
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    Publikationsdatum: 2011-08-18
    Beschreibung: Two full frames of radiometrically corrected (Type A) LANDSAT-4 MSS data were analyzed digitally and visually for evidence of residual calibration differences between detectors, quantization effects, and other sensor-related artifacts. Both standard statistical and Fourier analysis techniques were employed. Opportunities for coincident coverage by LANDSATS 3 and 4 were identified in the contiguous 48 states. Paired acquisitions for two scenes were obtained and analyzed to establish relationships between signal values from common areas imaged by the two MSS Systems. Initial findings on detector-to-detector differences, coherent noise, and LANDSAT 4 to LANDSAT 3 calibration are summarized. Results show that LANDSAT 4 MSS produces data of generally good quality with dynamic ranges and target responses similar to those of previous sensors.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: NASA. Goddard Space Flight Center LANDSAT-4 Sci. Characterization; 3 p
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  • 58
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    Publikationsdatum: 2011-08-18
    Beschreibung: Key spectral, radiometric, and geometric characteristics of the TM sensor are examined. Spectrally, band 5 is slightly wider than specified and its upper edge at 50% of miximum of 1784 nm includes some unintended overlap with water absorption bands. Thermal band 6 is half the expected width. Radiometrically, the TM has extreme linearity and stability in comparison with previous MSS photomultiplier systems. Forward and reverse scans on TM show some unexplained radiometric differences of up to four digital levels. Primary focal plane bands show a monotomic decrease in gain of about 5% in the five months since launch. The relative internal gains of bands 5 and 7 varied with a period of about 60 days and an amplitude of about 6%. Radiometric calibration must be applied before histogram equalization algorithms to preserve radiometric accuracy. Geometrically, channel 4 in band 2 has a smaller modulation transfer function than desired. There is apparent misregistration of .75 pixels along scan and 0.2 pixels across scan.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: LANDSAT-4 Sci. Characterization; 2 p
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  • 59
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    Publikationsdatum: 2011-08-18
    Beschreibung: The characterization objectives of the LANDSAT 4 Science Office at GSFC are to: (1) determine the accuracy and precision of sensor and spacecraft performance, image data quality, and derived information; (2) recommend LANDSAT 4 system improvements; and (3) communicate results to the research community. In-house activities are directed toward full access and utilization of the prelaunch and in-orbit engineering test data on the sensor and spacecraft. Principle scientists in remote sensing are involved as part of a major scientific characterization effort, and workshops were held for these investigative teams. A symposium is scheduled prior to turnover of the TM to NOAA.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: LANDSAT-4 Sci. Characterization; 2 p
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  • 60
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    Publikationsdatum: 2011-08-18
    Beschreibung: The LANDSAT 4 thematic mapper sensor possesses approximately twice the spectral resolution, three times the spatial resolution, and four times the spectral sensitivity of the MSS sensor on earlier LANDSAT satellites. Spectral bands on the TM, particularly those at wavelengths of 1.6 and 2.2 micrometers are useful for: (1) distinguishing crops such as rice and soybeans; (2) surveying areas that are cultivated in strip crop fashion; (3) determining clay variations and abundances and rock classifications; and (4) differentiating nutrients and sediments found in coastal waters. The sensor can identify surface features 30 meters on a side, which roughly corresponds to a standard city block. Highway construction, land excavation, urban growth, and the health and extent of vegetation can be detected.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Materialart: LANDSAT-4 Sci. Characterization; 3 p
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  • 61
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    Publikationsdatum: 2011-08-18
    Beschreibung: The VAS data which are used for studying and predicting numerous meteorological phenomena are discussed. These phenomena include severe local storm antecedent conditions, the formative stages of tropical cyclones, the definition of upper tropospheric circulation features, and as input to synoptic scale prediction models.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 49-50
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  • 62
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    Publikationsdatum: 2011-08-18
    Beschreibung: The understanding and utilization of radiance data from the VAS instrument for meteorological purposes which requires an extensive and organized research plan whose ultimate goal is to provide quantitative measurements of the structure/dynamics of the atmosphere is outlined. The unique multispectral VAS data are potentially useful in almost all aspects of meteorology but have immediate applications in the mesoscale and severe storm research area since measurements are available over regional areas at time intervals of less than 1 hour. The higher priority research applications of VAS data pertaining to the interpretation and utilization of the passive VAS radiance measurements for mesoscale and severe-storm research are reviewed.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 51-52
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  • 63
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    Publikationsdatum: 2011-08-18
    Beschreibung: The application of the VAS program is outlined. The initial assessments of VAS radiometer and satellite performance were satisfactory; and VAS operations were smoothly carried out by the NESS SOCC and associated processing and retransmission facilities. The availability of advanced image processing systems, previous studies with the geosynchronous European Space Agency Meteorological Satellite (Meteosat), and the polar orbiter multichannel radiance data enabled the progress of the application. The VAS data are implemented as these data are received in the real time VISSR mode, and as dwell sounding (DS) and multispectral imaging (MSI) radiances on magnetic tapes.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 45-47
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  • 64
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    Publikationsdatum: 2011-08-18
    Beschreibung: The visible/infrared spin scan radiometer (VISSR) atmospheric sounder (VAS) rawinsonde field program is discussed. Specific items covered include: planning, personnel requirements and training, operational requirement and procedures, sounding times and dates, methods of data processing, data inventory, and status of data processing.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 37-38
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  • 65
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    Publikationsdatum: 2011-08-18
    Beschreibung: The AVE/VAS ground truth field experiment was conducted during the Spring of 1982 severe storms and weather research program. The experiment consisted of acquiring correlative ground truth measurements of rawinsonde data, corresponding to the time and space resolutions of VAS sounding data. The objectives of the AVE/VAS experiment are: (1) to acquire four dimensional data sets of the actual atmospheric structure down to the mesoscale; (2) to provide measurements for quantitative comparisons between ground based and VAS-derived atmospheric parameters; (3) to evaluate the impact of VAS data on diagnostic analysis of structural features and dynamical processes important to the development of mesoscale phenomena; (4) to evaluate the impact of VAS data on numerical model simulations, nowcasting, and other mesoscale forecasting systems.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 39-43
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  • 66
    Publikationsdatum: 2011-08-18
    Beschreibung: A special network exercise supporting the VAS demonstration is reported. The second near-real time total ozone mapping spectrometer (TOMS) activity involving out of sequence processing of Nimbus-7 data over the United States and Europe is presented. The ozone data maps were used by airlines to search for regions of clear air turbulence and by an aircraft data gathering program, for synoptic upper air and tropopause height analyses. The TOMS total ozone levels are correlated with radiosonde tropopause height for testing the ability of TOMS data to give independent satellite measurements of tropopause height.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 31
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  • 67
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    Publikationsdatum: 2011-08-18
    Beschreibung: VAS retrieval capability was studied. A mesoscale event consisting of a rapidly moving temperature perturbation with strong horizontal wind shear but shallow vertical extent occurred over Texas. The mesoscale event passed through the special radiosonde network and was documented with three hourly measurements. The event occurred behind a cold frontal cloud band during clear conditions. The event was accompanied by large skin temperature changes as the day progressed. This combination allows the testing of two important aspects of the retrieval algorithms with minimal cloud contamination and good ground truth. The first aspect concerns the horizontal and vertical resolving power of the retrievals and the second aspect concerns sensitivity to the boundary term. The NASA special network radiosonde is proven to be useful. It is demonstrated that: the VAS is capable, of delineating a mesoscale, normal retrieval procedure has the deficiency of oversmoothing, but this can be corrected, to document first quess dependence, and a superior data set to evolve better techniques for treating the surface boundary problem.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 33-36
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  • 68
    Publikationsdatum: 2011-08-18
    Beschreibung: The effect of visible/infrared atmospheric sounder (VAS) data on the limited area fine mesh model (LFM) analysis forecast system were examined. The VAS data obtained from the Pacific geostationary satellite are valuable for LFM analysis because temperatures from the polar orbiting satellite over the east Pacific are received too late for 1200 GMT LFM analysis. Because the VISSR has only infrared channels, retrievals are possible only in regions with little or no cloudiness.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 27-28
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  • 69
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    Publikationsdatum: 2011-08-18
    Beschreibung: Infrared (IR) channels which are available and are developed for operational use were examined. The Visible Infrared Spin-Scan Radiometer (VISSR) Atmospheric Sounder (VAS) was launched. This instrument has a radiometer consisting of the standard visible channel detectors and six thermal detectors that detect IR radiation in 12 spectral bands. Any one of the 11 new IR channels can be substituted for the standard 11.5 micro m window channel when the satellite is operating in the standard VISSP mode and provides data in image form through the GOES distribution system.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 29-30
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  • 70
    Publikationsdatum: 2011-08-18
    Beschreibung: Data from the geostationary Visible Infrared Spin-Scan Radiometer (VISSR) Atmospheric Sounder (VAS) for assigning simultaneous heights and velocities of cloud motion winds were processed. The following two techniques are discussed: The technique which delivers qualitative height assignments from imagery; and which uses the radiometric information contained in the VAS data to calculate quantitative heights.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 25-26
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  • 71
    Publikationsdatum: 2011-08-18
    Beschreibung: An operational assessment of VAS data by using a Man-computer Interactive Data Access System (McIDAS) terminal linked by a 9600 band telephone line is discussed. Seven hours of VAS data were processed and edited daily. Data was scheduled 16 hours a day, 7 days a week; however, during this time period there were very few days with 16 hours of data to evalute. The McIDAS terminal, which has 10 display frames and 5 graphics, provide access to the sounding data processed. These data are processed using two procedures. The dwell sounding data are generated by using all 12 spectral channels with a spin budget of 39. To provide coverage for most of the United States, soundings are made starting at 18 minutes after the hour from approximately 49 deg N to 36 deg N and at 48 minutes after the hour from 36 deg N to 26 deg N. The dwell imaging mode uses 11 channels but the spin budge is 17. With the reduced spin budget, retrievals can be made at 18 or 48 minutes after the hour for approximately 44 deg N to 27 deg N. With these constraints a schedule, of data sets was proposed to use the schedule and how the data set could be used are shown.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 21-24
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  • 72
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    Publikationsdatum: 2011-08-18
    Beschreibung: The VAS soundings, produced in real time on an hourly basis, consistently delineate the areas of the country where intense convective weather will occur several hours in advance of the severe weather developments. This conclusion is based on the daily experience gained. An objective method of forecasting the probability of severe weather for 100 kilometer square areas of the United States from the VAS soundings was presented. An example sequence of these probability forecasts and the subsequent observed severe weather is included.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: NASA. Goddard Space Flight Center VISSR Atmospheric Sounder (VAS) Res. Rev.; p 17-19
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  • 73
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    Publikationsdatum: 2011-08-18
    Beschreibung: The sequence of events observed during tropical cyclone Emily, was suggested as a possible mechanism for cyclogenesis. Geostationary Operational Environmental Satellite (GOES) East VISSR/VAS sensors were used. The VISSR visible imagery obtained every 15 minutes was used to define the low tropospheric cyclonic vortex and upper tropospheric horizontal convergence. The VAS water vapor (channels 9 and 10) and carbon dioxide (channels 3 and 4) channels were used to infer upper and middle tropospheric subsidence by monitoring the Adiabatic compressional drying and warming, respectively, occurring within this layer. Evidence of an existing lower tropospheric cyclonic vortex was seen. The satellite derived wind vectors (length of vector is proportional to wind velocity, where the strongest winds were approximately 35 knots) are superimposed on the GOES visible image of tropical storm Emily. Vectors and low level clouds depict the center of the cyclonic vortex immediately south of the large convective cell in the center of the image. Upper tropospheric cloud tracers and rawinsonde reports along the Eastern United States suggest that the southwesterly environmental upper atmospheric flow is converging with the outflow from the convective cell north of the vortex.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 13-16
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  • 74
    Publikationsdatum: 2011-08-18
    Beschreibung: A statistical classification method based on clustering of multidimensional histograms was applied to several channels of the VAS multispectral imagery. The method automatically discriminates and classifies atmospheric ground features such as cloud types, atmospheric moisture patterns, ocean, or ground. Such a clustering method has the advantage of forming natural data groupings, without a priori classification. Clusters are not limited by straight lines or plane surfaces as is the case in threshold methods. The method was applied to simultaneous full resolution images from channels 8 (11.2 micron), 10 (6.7 micron), and 12 (3.9 micron). Twenty image segments of 64 by 64, 12 image segments of 128 by 128, and 4 image segments of 254 by 254 picture elements were analyzed. In addition, normal VISSR mode images at 1800, 1830, and 2000 GMT were used to identify the classes. The gray levels measured along a scan line and the result of the classification scheme (dashed curves) for the three channels investigated are shown. Each point of the image is affected to a class. Each class is identified by a center of gravity that is represented by a vector in the three dimensional space of gray levels.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 11-12
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  • 75
    Publikationsdatum: 2011-08-18
    Beschreibung: The information content of the VAS radiances can be converted to meteorological parameters useful for analyzing a severe weather environment. The method by which the VAS variances are converted to vertical profiles of temperature, dewpoints, and equivalent potential temperature involves a basic regression technique using the most local radiosonde data available for establishing a correlation matrix. The results indicate that mesoscale features apparent within images of the radiances can be converted to usable temperature and moisture fields using regression when surface temperature and dewpoint observations are included within the total data base. In addition, results indicate that surface data are very important for better defining lower tropospheric structure that the VAS radiances alone cannot properly resolve. Analyses of these retrievals distinctly show mesoscale structure in the temperature and moisture fields derived with VAS radiances collected every 3 hours, and 0000 GMT. The retrievals capture the moisture structure. More important, convective instability is clearly detected immediately before the onset of convection. The results indicate that the VAS is capable of providing valuable mesoscale information suitable for analyzing a preconvective environment that is generally clear.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 9
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  • 76
    Publikationsdatum: 2011-08-18
    Beschreibung: The utility of combining visible and various infrared images from the VAS to produce a forecasting tool, that can be available on a near real time basis, to predict severe weather development is shown. Areas where dry air in the midtroposphere overlays substantial moisture at low levels are used to diagnose mesoscale regions that have the potential for being convectively unstable before the onset of severe convection. Specifically, 6.7 micron water vapor imagery, used for isolating regions of substantial midlevel dryness, are combined with images of low level clouds or with split-window low level moisture images to delineate regions that have the potential for convective instability. In areas where scattered low level clouds are present, computer generated, color image combinations are used to isolate those warm, low level clouds that are in potential convectively unstable environments from clouds that exist under a deeply moist atmosphere. In clear regions, the split window technique is used for delineating areas of substantial boundary layer moisture. These images are again computer overlayed by the midlevel dryness to produce a color coded image of potential convective instability.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 7
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  • 77
    Publikationsdatum: 2011-08-18
    Beschreibung: Originally, the VAS split window channels were designed to use the differential water vapor absorption between 11 and 12 microns to estimate sea surface temperature by correcting for the radiometric losses caused by atmospheric moisture. It is shown that it is possible to reverse the procedure in order to estimate the vertically integrated low level moisture content with the background surface (skin) temperature removed, even over the bright, complex background of the land. Because the lower troposphere's water vapor content is an important factor in convective instability, the derived fields are of considerable value to mesoscale meteorology. Moisture patterns are available as quantitative fields (centimeters of precipitable water) at full VAS resolution (as fine as 7 kilometers horizontal resolution every 15 minutes), and are readily converted to image format for false color movies. The technique, demonstrated with GOES-5, uses a sequence of split window radiances taken once every 3 hours from dawn to dusk over the Eastern and Central United States. The algorithm is calibrated with the morning radiosonde sites embedded within the first VAS radiance field; then, entire moisture fields are calculated at all five observation times. Cloud contamination is removed by rejecting any pixel having a radiance less than the atmospheric brightness determined at the radiosonde sites.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 5-6
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  • 78
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    Publikationsdatum: 2011-08-18
    Beschreibung: The VAS, carried onboard the GOES 4 and 5 satellites, is a radiometer with 8 visible channel detectors and 6 thermal detectors that detect infrared radiation in 12 spectral bands. A filter wheel in front of the detector is used to achieve the spectral selection. The spatial resolution is 0.9 kilometer in the visible and 7 or 14 kilometers in the infrared depending on the detector used. Full Earth disk coverage is accomplished by spinning in the west to east direction at 100 rpm and by stepping a scan mirror from north to south. Additional VAS instrument characteristics are summarized. The VAS has three operating modes: the operational VISSR mode, the multispectral imaging (MSI) mode, and the dwell sounding (DS) mode. The operational VISSR mode is used by NOAA/NESS for its operational products, which include a visible picture and an 11 micrometer infrared (channel 8) picture at half hour intervals. The other modes are VAS unique. The MSI mode combines the operational VISSR capability (visible plus infrared window) with two additional spectral channels to provide half hourly full Earth disk imagery of atmospheric water vapor, temperature, and cloud distribution. The DS mode is used primarily for sounding to obtain the temperature and moisture profiles. In this mode, multiple spins on the same scan line in a given band are averaged to obtain the required signal to noise ratio for sounding.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Materialart: VISSR Atmospheric Sounder (VAS) Res. Rev.; p 1-3
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  • 79
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    Publikationsdatum: 2011-08-19
    Beschreibung: In the Advanced Adiabatic Development program, the following technology were identified as critical: piston development for oil-less, adiabatic engine; positive displacement compounding and charge system; experimental evaluation of the preheat concept; combustion system with positive ignition assist; and ceramic manufacturing technology. Of these five areas, ceramic manufacturing technology is the pacing item, and is already being addressed by several organizations. Therefore the four remaining areas need immediate attention. Since the lead time involved in engine development and production is long, this technology development should be done concurrently with the AAD engine development. A four year program is outlined which will simultaneously study these first four areas. This program requires two test rigs; one single cylinder adiabatic engine; and one multicylinder adiabatic turbocompound engine.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Advan. Automotive Diesel Assessment Program; 7 p
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  • 80
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    Publikationsdatum: 2011-08-19
    Beschreibung: A critique of the various characteristics of engine design influencing noise and attempts to indicator areas where attention is required to obtain noise acceptable engine for automobiles are discussed. It was concluded that the engine has a potential to be quiet beccause a ion rated speed is chosen. Problems with high gas pressure, the fuel injection pump, and the expander/compressor are discussed.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 29 p
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  • 81
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    Publikationsdatum: 2011-08-19
    Beschreibung: Preliminary selection and sizing of a positive displacement screw compressor-expander subsystem for a light-duty adiabatic diesel engine; development of a mathematical model to describe overall efficiencies for the screw compressor and expander; simulation of operation to establish overall efficiency for a range of design parameters and at given engine operating points; simulation to establish potential net power output at light-duty diesel operating points; analytical determination of mass moments of inertia for the rotors and inertia of the compressor-expander subsystem; and preparation of engineering layout drawings of the compressor and expander are discussed. As a result of this work, it was concluded that the screw compressor and expander designed for light-duty diesel engine applications are viable alternatives to turbo-compound systems, with acceptable efficiencies for both units, and only a moderate effect on the transient response.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 46 p
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  • 82
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    Publikationsdatum: 2011-08-19
    Beschreibung: The proposed design for the light duty diesel is an in-line four cylinder spark assisted diesel engine mounted transversely in the front of the vehicle. The engine has a one piece cylinder head, with one intake valve and one exhaust valve per cylinder. A flat topped piston is used with a cylindrical combustion chamber recessed into the cylinder head directly under the exhaust valve. A single ceramic insert is cast into the cylinder head to insulate both the combustion chamber and the exhaust port. A similar ceramic insert is cast into the head to insulate the intake port. A ceramic faceplate is pressed into the combustion face of the head to insulate the face of the head from hot combustion gas. The valve seats are machined directly into the ceramic faceplate for the intake valve and into the ceramic exhaust pot insert for the exhaust valve. Additional ceramic applications in the head are the use of ceramic valve guides and ceramic insulated valves. The ceramic valve guides are press fit into the head and are used for increased wear resistance. The ceramic insulated valves are conventional valves with the valve faces plasma spray coated with ceramic for insulation.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Advan. Automotive Diesel Assessment Program; 65 p
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  • 83
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    Publikationsdatum: 2011-08-19
    Beschreibung: A conceptual study of an advanced automotive diesel engine is discussed. The engine concept selected for vehicle installation was a supercharged 1.4 liter, 4 cylinder spark assisted diesel of 14:1 compression ratio. A compounding unit consisting of a Lysholm compressor and expander is connected to the engine crankshaft by a belt drive. The inlet air charge is heated by the expander exhaust gas via a heat exchanger. Four levels of technology achievement on the selected engine concept were evaluated, from state-of-the-art to the ideal case. This resulted in the fuel economy increasing from 53.2 mpg to 81.7 mpg, and the 0-60 mph time decreasing from 17.6 seconds to 10.9 seconds.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 18 p
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  • 84
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    Publikationsdatum: 2011-08-19
    Beschreibung: The introduction of ceramics to those parts suffering high thermal loading was successfully demonstrated, and there is no question that the 100 kw (134 hp) naturally aspirated engine of the future will be developed to produce up to 300 kw (402 hp) by the application of turbocharging or its equivalent. However, at the 60 - 80 kw (80 - 107 hp) size needed for the economic automotive engine, scaling down the 300 kw (402 hp) is beset by the laws of scale. The conventional four stroke diesel was not shown to be successful at the small high speed engine size. The opposed piston two stroke engine does not suffer the same laws of scale and engines in the low power range have already been marketed successfully. The half liter/cylinder Armstrong Whitworth Swing Beam Engine is the latest to be designed with the automotive market in mind. Its low noise structure and balanced linkage system coupled with advantages for easy start and potential use of low grade fuels, derived from its variable compression ratio and slow piston motion, qualifies it for the application.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 3 p
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  • 85
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    Publikationsdatum: 2011-08-19
    Beschreibung: An analysis of the frictional behavior of a roller crosshead configuration is given. This configuration consists of a piston which carries at the wristpin position a roller of large diameter which can roll on the cylinder liner surfaces. A preliminary assessment is given of whether the roller can roll on the cylinder liner without skidding, and what, if any, are the tribological implications of this approach to a dry lubricated design. The rotational speed of the roller must change during the stroke if it is not to slip on the cylinder liner. The maximum value of angular acceleration occurs at top dead center and bottom dead center. If the traction force on the rim of the roller, which is the product of the normal force due to piston side load and the coefficient of friction, is not sufficient to drive the roller through the necessary angular acceleration, sliding will occur. At 1,000 rpm, it appears that there will be a definite area of slip near each end of the stroke. The length of the area of slip may be of the order of 1/8 inch at each of these points.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Advan. Automotive Diesel Assessment Program; 9 p
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  • 86
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    Publikationsdatum: 2011-08-19
    Beschreibung: The objectives of this analytical study were: to select one advanced automotive diesel engine (AAD) concept which would increase the tank mileage of a 3,000 pound passenger car from the present 35 mpg to at least 52 mpg; to identify long term component research and development work required to bring the selected concept to fruition; and to prepare a development strategy that will bring the selected concept to a prototype testing phase. Cummins Engine Company has completed this study. The selected concept is a 4 stroke cycle, direct injection, spark assisted, advanced adiabatic diesel engine with positive displacement compounding plus expander and part load air preheating. The engine does not use a liquid coolant nor liquid lubricants. It is a 4 cylinder, in-line, 77 mm bore x 77 mm stroke, 1.434 liters displacement engine weighing 300 lb, and rated at 70 BHP at 3000 rpm. Installation dimensions are 621 mm length x 589 mm width x 479 mm height (24.4 inch x 22 inch x 18.9 inch).
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Advan. Automotive Diesel Assessment Program p; 59 p
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  • 87
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    Publikationsdatum: 2011-08-19
    Beschreibung: New concepts for engine performance improvement are seen through the adoption of heat regeneration techniques; advanced methods to enhance the combustion; and higher efficiency air handling machinery, such as the positive displacement helical screw expander and compressor. Each of these concepts plays a particular role in engine performance improvement. First regeneration has a great potential for achieving higher engine thermal efficiency through the recovery of waste energy. Although the concept itself is not new (this technique is used in the gas turbine), the application to reciprocating internal combustion engines is quite unusual and presents conceptual difficulties. The second important area is better control of the combustion process in terms of heat transfer characteristics, combustion products, and heat release rate. The third area for performance improvement is in the adoption of high efficiency air handling machinery. In particular, positive displacement helical expander and compressor exhibit an extremely high efficiency over a wide range of operating conditions.
    Schlagwort(e): MECHANICAL ENGINEERING
    Materialart: Advan. Automotive Diesel Assessment Program; 46 p
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  • 88
    Publikationsdatum: 2011-08-18
    Beschreibung: Estimates of clear-sky albedo and equivalent blackbody temperatures derived from the Geostationary Operational Environment Satellite are presented. Regional clear-sky albedo over South America at noon ranged from 10 to 22 percent during November 1978 and February 1979, mean clear-sky albedo over the continent remained fairly constant at about 12.4 percent. A slight seasonal decrease in albedo found in a number of large river valleys is attributed to seasonal flooding. The average clear-sky albedo varied diurnally by factors of 2.0 and 2.3 from the value at noon over desert and vegetated areas, respectively. The mean regional clear-sky equivalent blackbody temperature ranged from 283 to 295 K.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 89
    Publikationsdatum: 2011-08-18
    Beschreibung: The changing distributions of cloud cover are of particular importance in understanding the general circulation patterns of the Southern Hemisphere, whose prediction is hampered by the sparse sampling of physical qualities. In near-tropical areas, the diurnal solar heating cycle is noted to be directly responsible for many of the observed weather patterns. Among the atmosphere's familiar responses to this heating cycle are afternoon thunderstorms over tropical land areas and the 'burnoff' of morning fog or low stratus near coastal margins. Attention is given to these aspects of the atmospheric adjustment to the daily solar cycle in terms of regional scale mean cloudiness over part of the Southern Hemisphere.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 90
    Publikationsdatum: 2011-08-18
    Beschreibung: The purpose of this paper is to quantify the impact of the FGGE SOS on the GLAS analyses and forecasts in the Southern Hemisphere, and to evaluate the relative importance of its components, and in particular, the impact of the loss of surface buoys. This discussion is limited to the forecast impact of the FGGE system upon a region between 28 deg S and 56 deg S, 50 deg W-80 W which includes essentially the southern cone of South America. Although forecast skill is verified against the NMC analysis, which used only VTPR but no TIROS-N data in the Southern Hemisphere, enough conventional data exists over this region to avoid biased verifications.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 91
    Publikationsdatum: 2011-08-18
    Beschreibung: Further observational evidence is presented for the existence of large amplitude short stationary waves during the month of January, 1979 in the lee side of South America. These waves are noted not to have been produced by either topography or CISK; their cause was probably related to stronger tropical convective heating over the Amazon and central Pacific during January. This source of stationary forcing was associated with the weaker easterlies and stronger westerlies in the topics, which allowed free propagation of the energy from the stationary forcing into the extratropics.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 92
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    Publikationsdatum: 2011-08-18
    Beschreibung: The persistent features of large anomalies have been examined and the locations of blocking in the Southern Hemisphere were determined. The data set used here contains daily maps of 500 mb geopotential heights for 100 months (June 1, 1972 to Nov. 30, 1980) covering from 10S to 90S. The seasonal cycle was defined as a 8 year mean and the 8th (annual) and 16th (semiannual) Fourier components of the time series at each grid point. Anomalies were defined as the difference between the total field and the seasonal cycle for each grid point.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
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  • 93
    Publikationsdatum: 2011-08-18
    Beschreibung: The general circulation of the Southern Hemisphere is quite different from that of the Northern Hemisphere in many important ways. These include the barotropic nature of the stationary waves and the presence of a strong barotropic component to the mean zonal wind, the lack of a strong seasonal dependence of the transient eddies, and the dominant role played by eddies with periods less than 10 days compared to longer period fluctuations. Such differences attest to the importance of the altered nature of the orographic and thermal land-sea forcings in the Southern Hemisphere compared to the Northern Hemisphere. Some of the important features of the Southern Hemisphere circulation as simulated by the GLAS Seasonal Cycle Model (SCM) are presented. The geographical patterns of local variability and their seasonal shifts in the SCM are discussed and compared to observations.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Publikationsdatum: 2011-08-18
    Beschreibung: The results of a study to evaluate Landsat digital data, categorized by land cover, for input to the Maryland Automated Geographic Information (MAGI) system, the state georeferenced data base, are presented. Good correspondence is found between the MAGI system and Landsat data for six of seven categories: forest, water, crop/pasture, medium-density residential, low-density residential, and transitional (disturbed land, construction). Discrepancies between the results are found for commercial/industrial/institutional areas which are due to differences in interpretative methodologies, not to deficiencies in either data source. It is concluded that Landsat data are suitable for future Maryland land cover inventories, and can also be used to augment MAGI system data.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: The history of meteorological satellites is traced, together with current instrumental and data analysis capabilities. Photographs taken from rockets launched in the late 1950s encouraged placing spacecraft such as the Nimbus I in sunsynchronous orbit beginning in 1964, and eventually the GOES, GMS, TIROS and Meteosat spacecraft into GEO in the 1970s. Visible, UV, IR and microwave sensors provide data on cloud patterns, wind fields, vertical temperature and humidity profiles and the surface temperature. Corrections have been developed in the data analyses programs to account for the atmospheric effects on upwelling radiation, fractional cloudiness, cloud-top heights and cloud contamination factors.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
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    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: The history of cumulus research in the decade following World War II is reviewed in the perspective of the new ideas and advances made during the subsequent generation. Emphasis is placed upon pioneering aircraft measurements, evidence for entrainment, the early model attempts and their attendant controversies.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
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    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-18
    Beschreibung: The present investigation is concerned with the effects of cumulus clouds upon their surroundings, and the interaction of the cumulus scale of motion with the larger scales of motion in the tropics. Charney and Eliassen (1964) have conducted a study of the growth of the hurricane depression and proposed the CISK (Conditional Instability of the Second Kind) mechanism. The CISK concept was used in several of the pioneering models of hurricanes and tropical disturbances. Since the 1960's, the CISK concept has been generalized and extended. However, the feedback between convection and the large-scale flow is still positive. In the present investigation the philosophy is extended to a negative feedback which contributes to the stability (mainly in direction) of the trade winds. Attention is given to the classical Ekman layer and early CISK, cumulus momentum transports, the role of cumuli in the trade-wind moisture and heat budgets, the trade wind model, and the equatorial trough and hot tower hypothesis.
    Schlagwort(e): METEOROLOGY AND CLIMATOLOGY
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Publikationsdatum: 2011-08-18
    Beschreibung: One of the objectives of the Saginaw River Basin study is related to the development of a computer model to predict flood damages. The computer model is to be operational in June 1985. In order to achieve this objective, the input of land-use data into a data base consisting of 198,000 grid cells will be required. A planning technique using Spatial Analysis Methodology (SAM) was developed by the Corps of Engineers Hydrologic Engineering Center (HEC) to systematically handle these data. The HEC-SAM system uses the spatially oriented map data in a series of data management and analysis software programs for input to the Corps hydrologic and environmental models. Attention is given to data base development, Landsat digital data, the placement of the Landsat data into the grid cell data base, and the development of the land cover classification. The Landsat-2 MSS scene covering 85 percent of the Saginaw River Basin was geometrically corrected to a UTM coordinate system.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Publikationsdatum: 2011-08-18
    Beschreibung: Extensive studies conducted by several researchers using truck-mounted active microwave sensors have shown the sensitivity of these sensors to soil moisture variations. The logical extension of these results is the evaluation of similar systems at lower resolutions typical of operational systems. Data collected during a series of aircraft flights in 1978 and 1980 over four rangeland watersheds located near Chickasha, Oklahoma, were analyzed in this study. These data included scatterometer measurements made at 1.6 and 4.75 GHz using a NASA aircraft and ground observations of soil moisture for a wide range of moisture conditions. Data were analyzed for consistency and compared to previous truck and aircraft results. Results indicate that the sensor system is capable of providing consistent estimates of soil moisture under the conditions tested.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Publikationsdatum: 2011-08-18
    Beschreibung: A vegetation gradient model, based on a new surface hydrologic index and NOAA/AVHRR meteorological satellite data, has been analyzed along a 1300 km east-west transect across the state of Texas. The model was developed to test the potential usefulness of such low-resolution data for vegetation stratification and monitoring. Normalized Difference values (ratio of AVHRR bands 1 and 2, considered to be an index of greenness) were determined and evaluated against climatological and vegetation characteristics at 50 sample locations (regular intervals of 0.25 deg longitude) along the transect on five days in 1980. Statistical treatment of the data indicate that a multivariate model incorporating satellite-measured spectral greenness values and a surface hydrologic factor offer promise as a new technique for regional-scale vegetation stratification and monitoring.
    Schlagwort(e): EARTH RESOURCES AND REMOTE SENSING
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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