Column | Data Category | Explanation |
---|---|---|

1 | PRN | the satellite vehicle PRN number |

2 | MJD | the five digit Modified Julian Date and the fraction of day at the midpoint of the track |

3 | BGTK HHMM | hour and minute (in UTC) of the start of the track tracks begin at 1 second after the minute |

4 | TRK SEC | the track length in seconds (a full track is 780 seconds) |

5 | MC-GPS NS | the time difference (measured in nanoseconds) between UTC(USNO MC) and GPS time, referred to the midpoint of the pass via a linear fit |

6 | SLOPE PS/S | the slope determined via the linear fit to produce MC-GPS (measured in picoseconds per second) |

7 | RMS NS | the root mean square of the residuals of the linear fit used to produce MC-GPS |

8 | SAMP N | the number of data points used in the fit to produce MC-GPS |

9 | EL DG | the elevation (in degrees) of the satellite at the midpoint of the track (data prior to MJD 50846 gives elevation at beginning of track) |

10 | AZM DEG | the azimuth (in degrees) of the satellite at the midpoint of the track (data prior to MJD 50846 gives azimuth at beginning of track) |

11 | ION NS | the modeled ionospheric delay (measured in nanoseconds) referred to the midpoint of the pass via a linear fit |

12 | MC-SATCL NS | the time difference (measured in nanoseconds) between UTC(USNO MC) and satellite time, referred to the midpoint of the pass via a linear fit |

13 | SLOPE PS/S | the slope determined via the linear fit to produce MC-SATCL (measured in picoseconds per second) |

14 | TROP NS | the modeled tropospheric delay (measured in nanoseconds) referred to the midpoint of the pass via a linear fit |

What Time Is It? USNO Time Service Home Page

GPS Home Page at USNO

Time Service Dept., U.S. Naval Observatory, Washington, DC