Results 271 to 280 of about 26,090 (296)
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International Astronomical Union Colloquium, 1980
AbstractIn the past twenty years there has been a great amount of growth in radiometric observing methods, as well as in classical optical observations. Through radar ranging and Doppler observations of the planets and spacecraft, we have been able to improve our knowledge of the location and motion of the planets by several orders of magnitude and ...
Jay H. Lieske, E. Myles Standish
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AbstractIn the past twenty years there has been a great amount of growth in radiometric observing methods, as well as in classical optical observations. Through radar ranging and Doppler observations of the planets and spacecraft, we have been able to improve our knowledge of the location and motion of the planets by several orders of magnitude and ...
Jay H. Lieske, E. Myles Standish
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Celestial Mechanics, 1975
An algorithm is proposed for generating sequences of Chebyshev series which are the best approximations of an astronomical ephemeris in the sense of Chebyshev over large intervals of time. The criterion for a polynomial approximation of a function to be the best polynomial approximation of the function is that the error function present certain ...
Andrée Deprit-Bartholomé +2 more
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An algorithm is proposed for generating sequences of Chebyshev series which are the best approximations of an astronomical ephemeris in the sense of Chebyshev over large intervals of time. The criterion for a polynomial approximation of a function to be the best polynomial approximation of the function is that the error function present certain ...
Andrée Deprit-Bartholomé +2 more
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Precise On-Board Navigation of LEO Satellites with GNSS Broadcast Ephemerides
, 2020The availability of orbit information with high precision and low latency is a key requirement for many Earthobservation missions, predominantly in the field of radio occultation.
A. Hauschild, O. Montenbruck
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Physical Ephemerides of the Planets
1994In the previous chapter we have provided the means of accurately calculating the positions of the major planets. Anyone who frequently observes the planets, the Sun, or the Moon, is also interested in data that describe the aspect of the various bodies. The visual magnitude and the apparent angular diameter are data of fundamental importance.
Oliver Montenbruck, Thomas Pfleger
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Analysis of Phobos’ dynamical environment considering effects of ephemerides and physical libration
, 2020A dynamical model is developed in the body-fixed frame of Phobos, in which the high-precision gravity field and exact physical libration of Phobos, the gravity of Mars with J2, and the gravity perturbations of the Sun, Jupiter, and Earth are considered.
Yue Wang, Xiaojie Wu
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Satellite orbits and ephemerides
Celestial Mechanics, 1984This review considers theoretical work leading to the actual knowledge of the motions of all planetary satellites, except the Moon. It covers recent calculations of inequalities of satellites’ motions and the determination of their orbits on the basis of existing observational data.
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Martian satellite orbits and ephemerides
Planetary and Space Science, 2014Abstract We discuss the general characteristics of the orbits of the Martian satellites, Phobos and Deimos. We provide a concise review of the various descriptions of the orbits by both analytical theories and direct numerical integrations of their equations of motion.
Jacobson, R.A., Lainey, V.
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Accuracy evaluation of Doresa and Milena Galileo satellites broadcast ephemerides
2018 IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea), 2018On 22 August 2014 Doresa and Milena Galileo satellites were launched in wrong orbit. In November 2014 European space agency started a salvaged mission to make two satellites usable.
U. Robustelli, G. Benassai, G. Pugliano
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BDS-3 and GPS/Galileo integrated PPP using broadcast ephemerides
GPS Solutions, 2022Guo Chen +4 more
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1995
Our material contains ephemerides for all five planets.The distribution is very uneven: 41 texts and fragments for Jupiter, but only 12 for Saturn, 11 for Mercury, 9 for Venus, and 8 for Mars.
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Our material contains ephemerides for all five planets.The distribution is very uneven: 41 texts and fragments for Jupiter, but only 12 for Saturn, 11 for Mercury, 9 for Venus, and 8 for Mars.
openaire +2 more sources