Ephemeris

The satellite ephemeris provides the position of that satellite, at a given time, in the spherical polar coordinate system of right ascension and declination. This data is updated every three hours.

A single ephemeris is applicable to all signals and frequencies of a specific satellite. With this data the user can compute the Earth-Centered, Earth-Fixed (ECEF) coordinates of the Space Vehicle’s (SV) antenna phase centre position at GST time.

The ephemeris for each Galileo satellite is composed of 16 parameters, which are:

  • 6 keplerian parameters
  • 6 harmonic coefficients
  • 1 orbit inclination rate correction parameter
  • 1 LAN rate correction parameter
  • 1 mean motion correction parameter
  • 1 reference time parameter t0e for the ephemeris data set
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2 thoughts on “Ephemeris

    1. Ian Goodbody

      I am looking for the same data and have had some luck with the IGS data products at http://mgex.igs.org/IGS_MGEX_Products.html. They link you to an ftp archive that updates weekly. I have only found sp3 files which provide XYZ satellite positions in a specified reference frame.

      Alternatively, you can got to https://www.space-track.org/ and download the two-line element sets. The TLEs offer different Keplerian parameters than those given by the Galileo navigation messages, and with that I don’t know if TLEs offer the level of accuracy one would need for precise navigation but it may be good enough.

      Best of Luck,
      -IG

      Reply

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