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# Orbit characteristics

MichaelBartmess.Orbit characteristics

Datatype | Required | |
---|---|---|

Orbit Name | String | Yes |

Semi-Major Axis (km) | Real | No |

Eccentricity | Real | No |

Inclination (Degrees) | Real | No |

Period (Hours) | Real | No |

delta RAAN (J2) (deg / day) | Real | No |

delta Arg Perigee (J2) (deg / day) | Real | No |

delta RAAN (Moon) (deg / day) | Real | No |

delta Arg Perigee (Moon) (deg / day) | Real | No |

delta RAAN (Sun) (deg / day) | Real | No |

delta Arg Perigee (Sun) (deg / day) | Real | No |

Sum | Avg | Min | Max | |
---|---|---|---|---|

Semi-Major Axis (km) | 102060.0 | 25515.0 | 6700.0 | 42160.0 |

Eccentricity | 0.75 | 0.1875 | 0.0 | 0.75 |

Inclination (Degrees) | 119.4 | 29.85 | 0.0 | 63.4 |

Period (Hours) | 23.933334 | 11.966667 | 11.966667 | 11.966667 |

delta RAAN (J2) (deg / day) | -7.696 | -1.924 | -7.35 | -0.013 |

delta Arg Perigee (J2) (deg / day) | 12.083 | 3.02075 | 0.0 | 12.05 |

delta RAAN (Moon) (deg / day) | -0.005180000000000001 | -0.0012950000000000001 | -0.00338 | -1.9E-4 |

delta Arg Perigee (Moon) (deg / day) | 0.00939 | 0.0023475 | 0.0 | 0.00676 |

delta RAAN (Sun) (deg / day) | -0.00234 | -5.85E-4 | -0.00154 | -8.0E-5 |

delta Arg Perigee (Sun) (deg / day) | 0.0042699999999999995 | 0.0010674999999999999 | 0.0 | 0.00307 |

This data set contains the orbit characteristics of several well-known orbits engineered for specific applications:

- The shuttle orbit
- The GPS orbit
- The Molniya orbit
- The Geosynchronous orbit

# Notes

**Global Positioning Satellites (GPS)** ==

The GPS constellation was originally designed to have 24 satellites, eight each in three approximately circular orbits. The original constellation architecture was changed to have six orbital planes with four satellites in each orbital plane.

**Characteristics of the GPS Satellite's Orbit**

- The orbital period of a GPS satellite is 1/2 sidereal day (approximately 11 hours and 58 minutes).
- The six orbital planes have approximately a 55 degree orbit inclination.
- The GPS satellites are separated by 60 degrees in right ascension of the ascending node (RAAN).
- The angular separations between the successive four satellites in a GPS orbital plane is 30, 105, 120, and 105 degrees
- The satellites orbit at an altitude of approximately 20,200 km (12,600 mi), so their orbit's radius is about 26,600 km (16,500 mi)

The satellites are arranged to provide coverage by at least six satellites at all times for most locations on the Earth.

As of December 2012, there are 32 satellites in the GPS constellation. The additional satellites provide increased precision in GPS receivers. With the increased number of satellites and some more recent changes to the constellation, nine satellites are visible from any point on the Earth.

**Orbit characteristics**, is listed in 1 Collection.