GALILEO is the global navigation satellite
system (GNSS) created by the European Union (EU) through the European GNSS
Agency (GSA).
GALILEO provides an alternative to both the United States
Global Positioning System and Russian Global
Navigation Satellite System, offering global coverage with
equal or greater precision.
The €10 billion project is named after the Italian
astronomer
Galileo Galilei.
GALILEO Operation
GALILEO
is intended to be a EU civilian GNSS that provides free and unrestricted
access to anyone with a compatible receiver.
GALILEO is
designed to provide the highest possible precision (greater than GPS) to all
users.
GALILEO
also provides an encrypted higher-bandwidth improved-precision commercial
service that
is available to paying customers.
GALILEO is designed to provide
horizontal and vertical position measurements with 1-metre precision, with
better positioning services at higher latitudes compared to other
positioning systems.
GALILEO is also to provide a new
global search and rescue (SAR) function as part of the MEOSAR system.
GALILEO
Services
The GALILEO system will have five primary services:
Open access navigation -
This will be available without charge for use by anyone with appropriate
mass-market equipment; simple timing, and positioning down to 1 meter.
Commercial navigation (encrypted) -
Accuracy to 1 centimeter and guaranteed service for which service providers
will charge fees.
Safety of life navigation - Open
service; for applications where guaranteed precision is essential. Integrity
messages will warn of errors.
Public regulated navigation (encrypted)
- Continuous availability even if other services are disabled in time of
crisis. Government agencies will be main users.
Search and rescue - System will pick up
distress beacon locations; feasible to send feedback, e.g. confirming help
is on its way.
GALILEO Coverage
The constellation operates in three orbital planes,
56° inclination, ascending nodes separated by 120° longitude (8 operational
satellites and 2 active spares per orbital plane).
GALILEO navigation signals will provide good
coverage at latitudes up to 75°
north (which corresponds to Norway's North Cape).
To get a position fix, the receiver must be in the range of at least four satellites, three of which will be used to determine the user's location and the fourth to synchronize clocks of the receiver and the three other spacecraft.
GALILEO Availability
Initial services became available on 15
December 2016.
A complete 30-satellite GALILEO
system (24 operational and 6 active spares) is expected by 2020.
Do I Need GALILEO?
Many modern
GPS receivers (GPSr) are able to use both GALILEO and GPS satellites simultaneously.
GPS + GALILEO provides improved coverage and quicker time to fix due to
having more than 50 satellites available.
Offering
dual frequencies as standard, GALILEO is set to deliver real-time
positioning accuracy down to the meter range.
For indoor, urban, canyon or mountainous areas, accuracy can be greatly improved over using GPS alone.