ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Other Sources  (31)
  • EARTH RESOURCES AND REMOTE SENSING  (14)
  • STRUCTURAL MECHANICS  (9)
  • Aerodynamics  (8)
  • 2005-2009  (7)
  • 1985-1989  (24)
  • 1
    facet.materialart.
    Unknown
    Reflectance and transmittance of snow at high spectral resolution (1989)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: A radiative-transfer model for the bidirectional reflectance-distribution function (BRDF) shows that snow is moderately anisotropic in the NIR wavelengths. Although the directional-hemispherical albedo of snow decreases as the grains become larger, the forward scattering also increases, with the result that the illumination and viewing geometry must be considered when interpreting physical properties of the surface layer of the snow pack from remote sensing data. Measurements of the BRDF and the transmittance for a variety of snow conditions were made throughout the winter and spring seasons with an SE-590 spectroradiometer, for wavelengths from 0.38 to 1.11 microns. Coincident with these, the surface grain properties were analyzed by stereological methods. A sphere with the same surface-to-volume ratio as the ice grains is used as the equivalent sphere.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    The Critical Role of Computational Fluid Dynamics in Rotary-Wing Aerodynamics (1986)
    In:  Other Sources
    Details
    Publication Date: 2011-08-23
    Description: Helicopter rotor aerodynamics is basically the study of unsteady aerodynamic flows in a rotating and translating coordinate system. Current trends in this field are briefly reviewed by examining recent advances in lifting-surface theory, wake modeling, panel methods, and finite-difference models' Examples are used to illustrate selected current methods and some indications of promising future directions are highlighted.
    Keywords: Aerodynamics
    Type: Vertica (ISSN 0360-5450); Volume 11; Nos. 1, 2; 43-63
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Snow property measurements correlative to microwave emission at 35 GHz (1987)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Snow microstructure, measured by plane section analysis, and snow wetness, measured by the dilution method, are used to calculate input parameters for a microwave emission model that uses the radiative transfer method. The scattering and absorbing properties are calculated by Mie theory. The effects of different equivalent sphere conversions, adjustments for near-field interference, and different snow wetness characterizations are compared for various snow conditions. The concentric shell geometry of liquid water in snow yields higher emissivities and better model results than the separate-sphere configuration for liquid water contents greater than 0.05, while at lower liquid water contents the separate-sphere treatment gives better results.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: IEEE Transactions on Geoscience and Remote Sensing (ISSN 0196-2892); GE-25; 751-757
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Covariance of greenness and terrain variables over the Konza Prairie (1989)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: An analysis is made of time-dependent covariance of the greenness vegetation index with mapped terrain variables over the Konza Prarie (Kansas) during the 1987 growing season. The analysis was part of an ongoing project to establish appopriate ground-sampling and data-integration strategies for satellite-based monitoring of land surface climate conditions. Greenness images for six dates between May and October were derived from atmospherically corrected thematic mapper (TM) data and coregistered with maps of woody vegetation, fire, and soils. Local variance in greenness peaked in mid-June, falling rapidly until mid-August, and declining gradually thereafter. Greenness images exhibited positive autocorrelation up to distances of 180-210 m, but the dominant scale of pattern occurred at a block size of 60 m by 60 m throughout the growing season. 40-44 percent of total scene variance in July and August was accounted for by the effects of woody vegetation (8.9 percent of the area), prairie burning, and soil type. The effect of these terrain variables was fairly consistent between June and late August and was manifested as additional high-frequency spatial variation in imagery from that period.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Workshop on Structural Dynamics and Control Interaction of Flexible Structures (1987)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The Hubble Space Telescope features the most exacting line of sight jitter requirement thus far imposed on a spacecraft pointing system. Consideration of the fine pointing requirements prompted an attempt to isolate the telescope from the low level vibration disturbances generated by the attitude control system reaction wheels. The primary goal was to provide isolation from axial component of wheel disturbance without compromising the control system bandwidth. A passive isolation system employing metal springs in parallel with viscous fluid dampers was designed, fabricated, and space qualified. Stiffness and damping characteristics are deterministic, controlled independently, and were demonstrated to remain constant over at least five orders of input disturbance magnitude. The damping remained purely viscous even at the data collection threshold of .16 x .000001 in input displacement, a level much lower than the anticipated Hubble Space Telescope disturbance amplitude. Vibration attenuation goals were obtained and ground test of the vehicle has demonstrated the isolators are transparent to the attitude control system.
    Keywords: STRUCTURAL MECHANICS
    Type: Structural Dynamics and Control Interaction of Flexible Structures; p 669-690
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Snow property measurements correlative to microwave emission at 35 GHz (1986)
    In:  Other Sources
    Details
    Publication Date: 2013-08-29
    Description: Snow microstructure, measured by plane section analysis, and snow wetness, measured by the dilution method, are used to calculate input parameters for a microwave emission model that uses the radiative transfer method. The scattering and absorbing properties are calculated by Mie theory. The effects of different equivalent sphere conversions, adjustments for near-field interference, and different snow wetness characterizations are compared for various snow conditions. The concentric shell geometry of liquid water in snow yields higher emissivities and better model results than the separate-sphere configuration for liquid water contents greater than 0.05, while at lower liquid water contents the separate-sphere treatment gives better results.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: ESA Proceedings of the 1986 International Geoscience and Remote Sensing Symposium (IGARSS '86) on Remote Sensing: Today's Solutions for Tomorrow's Information Needs, Volume 2; p 915-920
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    The spectral bidirectional reflectance of snow (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-29
    Description: A radiative transfer model for the bidirectional reflectance-distribution function (BRDF) shows that snow is moderately anisotropic in the near-infrared wavelengths. Although the directional-hemispherical albedo of snow decreases as the grains become larger, the forward scattering also increases, with the result that the illumination and viewing geometry must be considered when interpreting physical properties of the surface layer of the snow pack from remote sensing data. Measurements of the BRDF for a variety of snow conditions were made throughout the winter and spring seasons with a spectroradiometer, for wavelengths from 0.38 to 1.11 microns. Coincident with these the surface grain properties were analyzed by stereological methods. The data show that Mie scattering calculations using an equivalent spherical radius match the directional-hemispherical reflectance, but the BRDF usually shows a small peak in the backscattered direction that would not occur from spherical grains. The sphere with the same surface-to-volume ratio as the ice grains is used as the equivalent sphere.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: ESA, Proceedings of the 4th International Colloquium on Spectral Signatures in Remote Sensing; p 87-92
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Application of Thermal Infrared Multiband Scanner (TIMS) data to mapping of Plutonic and stratified rock and assemblages in accreted terrains of the Northern Sierra, California (1986)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The Thermal Infrared Multispectral Scanner (TIMS) data were acquired over the Donner Pass area in California on September 12, 1985. The higher peaks in the area approach 9,200 feet in elevation, while the canyon of the north fork of the American River is only 3000 feet in elevation. The vegetation is dominated by conifers, although manzanita and other shrubs are present in areas where soils have developed. The data contain noise patterns which cut across scan lines diagonally. The TIMS data were analyzed using both photointerpretative and digital processing techniques. Preliminary image interpretation and field analysis confirmed that TIMS image data displays the chert units and silicic volcanics as bright red. The imagery appears to display zoning in the batholithic and hypabyssal intrusive rocks, although this was not field checked at this time. Rocks which appear to be more dioritic in composition appear purple on the imagery, while rocks more granitic in composition appear shades of red and pink. Areas that have more than 40% vegetative cover appear green on the imagery.
    Keywords: EARTH RESOURCES AND REMOTE SENSING
    Type: JPL, California Inst. of Technology The TIMS Data User's Workshop; p 71-73
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    A method for determining crack opening load from load-displacement data (1988)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The fatigue crack opening load is determined as the tangent point on the ascending load-displacement data between the curved portion and the upper linear region. A model for the 'unzipping' behavior of the crack indicates that the curved portion of the load-deflection curve is second order. The opening load is determined by a nonlinear, least squares fit of the data to the model, which optimally locates the tangent point of the two curves. The method provided consistent results for determining opening load P(op) for 7475-T731 aluminum using data from a crack tip opening gage.
    Keywords: STRUCTURAL MECHANICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Viscous damped space structure for reduced jitter (1987)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: A technique to provide modal vibration damping in high performance space structures was developed which uses less than one once of incompressible fluid. Up to 50 percent damping can be achieved which can reduce the settling times of the lowest structural mode by as much as 50 to 1. This concept allows the designers to reduce the weight of the structure while improving its dynamic performance. Damping by this technique is purely viscous and has been shown by test to be linear over 5 orders of input magnitude. Amplitudes as low as 0.2 microinch were demonstrated. Damping in the system is independent of stiffness and relatively insensitive to temperature.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA-Marshall Space Flight Center, The 58th Shock and Vibration Symposium, Volume 1; p 233-243
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...