Galileo runs on Galileo System Time (GST), which is under responsibility of the Galileo Mission Segment (GMS). GST is fixed on the ground at the Galileo Control Centre in Fucino (Italy) by the Precise Timing Facility (PTF), based on the average of different atomic clocks. Read more…
The traditional orbital elements that identify a specific orbit are the six Keplerian parameters.
The main two elements that define the shape and size of the ellipse: Read more…
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. Read more…
The navigation data contain all the parameters that enable the user to position. They are stored on board each satellite with a validity duration and broadcast worldwide by all the satellites of the Galileo constellation. These are the 4 types of data needed to perform positioning: Read more…
There exist two types of I/NAV pages: Nominal and Alert pages.
Nominal pages have a duration of 2 seconds and they are transmitted sequentially in time in two parts of duration 1 second each in both E5b and E1frequency bands. The first part of a page is denoted “even” and the second one is denoted “odd”. Read more…
The I/NAV messages are used in Safety of Life (SoL). The I/NAV message structures are tarnsmitted in E5b (1207.14 MHz) and E1 (1575.42 MHz) frequency bands. In both frequencies the same page layout is used since the service provided on these frequencies is a dual frequency service, using frequency diversity. Read more…
The page is the basic structure for building the navigation message. They can be found the following fields within a page:
Sync: The synchronization pattern (101101110000), which is not encoded, allows the receiver to achieve synchronisation to the page boundary Read more…