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
  • 1
    facet.materialart.
    Unknown
    Precision orbit computations for an operational environment (1981)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Taking advantage of the improvements to the Earth's gravitation field and tracking station coordinates, an orbital computational consistency of the order of 5 meters was achieved for total position differences between orbital solutions for the Seasat and GEOS-3. The main source of error in these solutions was in the mathematical models that are required to generate these results, i.e., gravitation, atmospheric drag, etc. Different Earth gravitation fields and tracking coordinates were analyzed and evaluated in obtaining these computational results. Comparisons and evaluations of the Seasat results were obtained in terms of different solution types such as the Doppler only, Laser only, Doppler and Laser, etc. Other investigation using the Seasat data were made in order to determine their effect on the computational results at this particular level of consistency.
    Keywords: ASTRODYNAMICS
    Type: Sixth Ann. Flight Mech.(Estimation Theory Symp.; 36 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    An explanation of subprotonospheric whistlers. (1964)
    In:  Other Sources
    Details
    Publication Date: 2019-05-24
    Description: Subprotonospheric whistler reflections at 1000 km attributed to energy refraction by hydrogen ions
    Keywords: COMMUNICATIONS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Study of a homotopy continuation method for early orbit determination with the Tracking and Data Relay Satellite System (TDRSS) (1986)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A recent mathematical technique for solving systems of equations is applied in a very general way to the orbit determination problem. The study of this technique, the homotopy continuation method, was motivated by the possible need to perform early orbit determination with the Tracking and Data Relay Satellite System (TDRSS), using range and Doppler tracking alone. Basically, a set of six tracking observations is continuously transformed from a set with known solution to the given set of observations with unknown solutions, and the corresponding orbit state vector is followed from the a priori estimate to the solutions. A numerical algorithm for following the state vector is developed and described in detail. Numerical examples using both real and simulated TDRSS tracking are given. A prototype early orbit determination algorithm for possible use in TDRSS orbit operations was extensively tested, and the results are described. Preliminary studies of two extensions of the method are discussed: generalization to a least-squares formulation and generalization to an exhaustive global method.
    Keywords: ASTRODYNAMICS
    Type: NASA-TM-86230 , NAS 1.15:86230
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Ion cyclotron whistlers. (1965)
    In:  Other Sources
    Details
    Publication Date: 2019-05-24
    Description: Proton whistler /VLF phenomenon observed in satellite data/ discussing propagation in multicomponent plasma and ion cyclotron mode
    Keywords: COMMUNICATIONS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Lower hybrid resonance emissions. (1965)
    In:  Other Sources
    Details
    Publication Date: 2019-05-24
    Description: Unusual noise band observed in VLF recordings of Alouette, investigating resonance in plasma surrounding satellite
    Keywords: COMMUNICATIONS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Propagation in multicomponent plasmas. (1964)
    In:  Other Sources
    Details
    Publication Date: 2019-05-24
    Description: Radio propagation modes in multicomponent plasma such as ionosphere, examing cutoff and crossover frequency resonances
    Keywords: COMMUNICATIONS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Orbit determination and prediction study for Dynamic Explorer 2 (1983)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Definitive orbit determination accuracy and orbit prediction accuracy for the Dynamic Explorer-2 (DE-2) are studied using the trajectory determination system for the period within six weeks of spacecraft reentry. Baseline accuracies using standard orbit determination models and methods are established. A promising general technique for improving the orbit determination accuracy of high drag orbits, estimation of random drag variations at perigee passages, is investigated. This technique improved the fit to the tracking data by a factor of five and improved the solution overlap consistency by a factor of two during a period in which the spacecraft perigee altitude was below 200 kilometers. The results of the DE-2 orbit predictions showed that improvement in short term prediction accuracy reduces to the problem of predicting future drag scale factors: the smoothness of the solar 10.7 centimeter flux density suggests that this may be feasible.
    Keywords: ASTRODYNAMICS
    Type: NASA-TM-85098 , NAS 1.15:85098
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Techniques for increasing the efficiency of Earth gravity calculations for precision orbit determination (1981)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Two techniques were analyzed. The first is a representation using Chebyshev expansions in three-dimensional cells. The second technique employs a temporary file for storing the components of the nonspherical gravity force. Computer storage requirements and relative CPU time requirements are presented. The Chebyshev gravity representation can provide a significant reduction in CPU time in precision orbit calculations, but at the cost of a large amount of direct-access storage space, which is required for a global model.
    Keywords: ASTRODYNAMICS
    Type: NASA. Goddard Space Flight Center Sixth Ann. Flight Mech.(Estimation Theory Symp.; 28 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Definitive orbit determination for the HEAO-2 spacecraft (1984)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Precise ephemerides for the High Energy Astronomy Observatory-2 (HEAO-2) were computed to assist in the Charles Stark Draper Laboratory development of an onboard orbit determination technique. Weighted least-squares, batch orbit solutions were calculated using a high-precision earth gravity model and an approximate model for intermittent spacecraft thrusting. With these improvements, orbit solution consistencies at the 50- to 100-meter level were attained using the Goddard Trajectory Determination System and NASA S-band tracking data.
    Keywords: ASTRODYNAMICS
    Type: AAS PAPER 83-317
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Study of magnetospheric field oriented irregularities - The mode theory of bell- shaped ducts (1971)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Whistler wave propagation along bell shaped ducts of enhanced ionization in magnetosphere
    Keywords: COMMUNICATIONS
    Type: ; VUE SCIENTIFIQUE ET
    Format: text
    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...