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
  • ASTRODYNAMICS  (10)
  • SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING  (3)
Collection
Keywords
Years
  • 1
    facet.materialart.
    Unknown
    Relative performance of algorithms for autonomous satellite orbit determination (1981)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Limited word size in contemporary microprocessors causes numerical problems in autonomous satellite navigation applications. Numerical error introduced in navigation computations performed on small wordlength machines can cause divergence of sequential estimation algorithms. To insure filter reliability, square root algorithms have been adopted in many applications. The optimal navigation algorithm requires a careful match of the estimation algorithm, dynamic model, and numerical integrator. In this investigation, the relationship of several square root filters and numerical integration methods is evaluated to determine their relative performance for satellite navigation applications. The numerical simulations are conducted using the Phase I GPS constellation to determine the orbit of a LANDSAT-D type satellite. The primary comparison is based on computation time and relative estimation accuracy.
    Keywords: SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING
    Type: Journal of the Astronautical Sciences; 29; Jan
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Precision orbit determination software validation experiment (1980)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: This paper presents the results of an experiment which was designed to ascertain the level of agreement between GEODYN and UTOPIA, two completely independent computer programs used for precision orbit determination, and to identify the sources which limit the agreement. For a limited set of models and a seven-day data set arc length, the altitude components of the ephemeris obtained by the two programs agree at the sub-centimeter level throughout the arc.
    Keywords: ASTRODYNAMICS
    Type: Journal of the Astronautical Sciences; 28; Oct
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Autonomous satellite navigation methods using the Global Positioning Satellite System (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: This investigation considers the problem of autonomous satellite navigation using the NAVSTAR Global Positioning System (GPS). The major topics covered include the design, implementation, and validation of onboard navigation filter algorithms by means of computer simulations. The primary errors that the navigation filter design must minimize are computational effects and modeling inaccuracies due to limited capability of the onboard computer. The minimization of the effect of these errors is attained by applying the sequential extended Kalman filter using a factored covariance implementation with Q-matrix or dynamical model compensations. Peformance evaluation of the navigation filter design is carried out using both the CDC Cyber 170/750 computer and the PDP-11/60 computer. The results are obtained assuming the Phase I GPS constellation, consisting of six satellites, and a Landsat-D type spacecraft as the model for the user satellite orbit.
    Keywords: SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Advanced simulation and analysis of a geopotential research mission (1988)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Computer simulations have been performed for an orbital gradiometer mission to assist in the study of high degree and order gravity field recovery. The simulations were conducted for a satellite in near-circular, frozen orbit at a 160-km altitude using a gravitational field complete to degree and order 360. The mission duration is taken to be 32 days. The simulation provides a set of measurements to assist in the evaluation of techniques developed for the determination of the gravity field. Also, the simulation provides an ephemeris to study available tracking systems to satisfy the orbit determination requirements of the mission.
    Keywords: ASTRODYNAMICS
    Type: NASA-CR-182355 , NAS 1.26:182355
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Orbit accuracy assessment for Seasat (1980)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Laser range measurements are used to determine the orbit of Seasat during the period from July 28, 1978, to Aug. 14, 1978, and the influence of the gravity field, atmospheric drag, and solar radiation pressure on the orbit accuracy is investigated. It is noted that for the orbits of three-day duration, little distinction can be made between the influence of different atmospheric models. It is found that the special Seasat gravity field PGS-S3 is most consistent with the data for three-day orbits, but an unmodeled systematic effect in radiation pressure is noted. For orbits of 18-day duration, little distinction can be made between the results derived from the PGS gravity fields. It is also found that the geomagnetic field is an influential factor in the atmospheric modeling during this time period. Seasat altimeter measurements are used to determine the accuracy of the altimeter measurement time tag and to evaluate the orbital accuracy.
    Keywords: ASTRODYNAMICS
    Type: Journal of the Astronautical Sciences; 28; Oct
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    A comparison of filtering algorithms for GPS satellite navigation application (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A comparison of three square root filter formulations with the standard extended Kalman filter is described. The characteristics of the algorithms were compared by simulating the application of a phase one GPS system to the determination of a LANDSAT-D Satellite.
    Keywords: ASTRODYNAMICS
    Type: NASA. Goddard Space Flight Center Flight Mech.(Estimation Theory Symp.; p 253-2279
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Geophysical parameters from the analysis of laser ranging to starlette (1987)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Starlette Satellite Laser Ranging (SLR) data were used, along with several other satellite data sets, for the solution of a preliminary gravity field model for TOPEX, PTGF1. A further improvement in the earth gravity model was accomplished using data collected by 12 satellites to solve another preliminary gravity model for TOPEX, designated PTGF2. The solution for the Earth Rotation Parameter (ERP) was derived from the analysis of SLR data to Starlette during the MERIT Campaign. Starlette orbits in 1976 and 1983 were analyzed for the mapping of the tidal response of the earth. Publications and conference presentations pertinent to research are listed.
    Keywords: ASTRODYNAMICS
    Type: NASA-CR-180596 , NAS 1.26:180596
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Accuracy assessment of GPS satellite orbits (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: GPS orbit accuracy is examined using several evaluation procedures. The existence is shown of unmodeled effects which correlate with the eclipsing of the sun. The ability to obtain geodetic results that show an accuracy of 1-2 parts in 10 to the 8th or better has not diminished.
    Keywords: ASTRODYNAMICS
    Type: of the COSPAR 28th Plenary Meeting, The Hague, Netherlands, June 25-July 6, 1990. A91-47626 20-12) Advances in Space Research (ISSN 0273-1177); 189-192
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Application of Encke's method to long arc orbit determination solutions (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Keywords: ASTRODYNAMICS
    Type: Journal of Guidance, Control, and Dynamics (ISSN 0731-5090); 14; 683-686
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Precision orbit determination for Topex (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: The ability of radar altimeters to measure the distance from a satellite to the ocean surface with a precision of the order of 2 cm imposes unique requirements for the orbit determination accuracy. The orbit accuracy requirements will be especially demanding for the joint NASA/CNES Ocean Topography Experiment (Topex/Poseidon). For this mission, a radial orbit accuracy of 13 centimeters will be required for a mission period of three to five years. This is an order of magnitude improvement in the accuracy achieved during any previous satellite mission. This investigation considers the factors which limit the orbit accuracy for the Topex mission. Particular error sources which are considered include the geopotential, the radiation pressure and the atmospheric drag model.
    Keywords: ASTRODYNAMICS
    Type: Advances in Space Research (ISSN 0273-1177); 10; 4-Mar
    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...