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Chapter 4 Finding Your Location with the Global Positioning System
recently been added to Mexico and Canada to greatly expand the range of
WAAS benefits). Other systems exist beyond WAAS and DGPS but use similar
concepts (some sort of correction is calculated and transmitted to a receiver
for it to use in its position determination).
What Other GNSS Are There Beyond GPS?
This chapter has been devoted to the operation, errors, and accuracy issues
surrounding GPS, but as mentioned early on, “GPS” refers to the US NAVSTAR GPS. Other countries have developed (or are in the process of developing) their own versions of GPS or GPS augmentation systems, presumably as
not to be completely dependent on U.S. technology. There are other full constellations of GPS-style satellites being developed and placed into orbit, with
numerous other enhancement systems in operation or in planning around
the globe.
GLONASS was the name of the USSR’s counterpart to GPS and operated in a similar fashion. The GLONASS equivalent to the C/A code operated at horizontal accuracies of about 100 m (or better) with an equivalent
of the P code for more accurate use. GLONASS consisted of a full constellation of satellites with an orbital setup similar to GPS. By 2001, however,
there were only a few GLONASS satellites in operation, but Russia now has
a renewed program and more GLONASS satellites have been launched, to
possibly have a full operational constellation in the near future. In 2007,
Russia indicated that the civilian signal from GLONASS would be made freely
available for use.
Galileo is the European Union’s version of GPS, which, when completed, is projected to have a constellation of 30 satellites and operate in a
similar fashion to GPS. The first of the GIOVE (Galileo In Orbit Validation
Element) satellites was launched in 2005, and the program has continued
development from then. Galileo promises four different types of signals, including information available to civilians as well as restricted signals. Also
in development is China’s version of GPS, Compass, which is projected to
also have a full constellation of satellites. The first Compass satellite was
launched in 2007.
Other Satellite Based Augmentation Systems have been developed across
the world to act similar to WAAS but to function in other regions outside of
North America. EGNOS (European Geostationary Navigation Overlay System) is sponsored by the European Union to provide improved accuracy of
GPS throughout Europe. EGNOS functions the same way WAAS does—a series of base stations throughout Europe monitor GPS satellite data, calculate
corrections, then transmit this correction to geostationary EGNOS satellites
over Europe, and these satellites broadcast this data to Earth. An EGNOSenabled receiver is necessary to utilize this correction data, and the system
is capable of accuracies of about 1.5 meters. Another SBAS operates out of
Japan, called MSAS (Multifunctional Satellite Augmentation System), which
GLONASS the
former USSR’s (now
Russia’s) GNSS,
currently rebuilding
to a constellation of
satellites.
Galileo the European
Union’s GNSS, currently
in development.
EGNOS a Satellite
Based Augmentation
System that covers
Europe.
Compass China’s
GNSS, currently in
development.
MSAS a Satellite Based
Augmentation System
that covers Japan and
nearby regions.
Chapter 4 Finding Your Location with the Global Positioning System
recently been added to Mexico and Canada to greatly expand the range of
WAAS benefits). Other systems exist beyond WAAS and DGPS but use similar
concepts (some sort of correction is calculated and transmitted to a receiver
for it to use in its position determination).
What Other GNSS Are There Beyond GPS?
This chapter has been devoted to the operation, errors, and accuracy issues
surrounding GPS, but as mentioned early on, “GPS” refers to the US NAVSTAR GPS. Other countries have developed (or are in the process of developing) their own versions of GPS or GPS augmentation systems, presumably as
not to be completely dependent on U.S. technology. There are other full constellations of GPS-style satellites being developed and placed into orbit, with
numerous other enhancement systems in operation or in planning around
the globe.
GLONASS was the name of the USSR’s counterpart to GPS and operated in a similar fashion. The GLONASS equivalent to the C/A code operated at horizontal accuracies of about 100 m (or better) with an equivalent
of the P code for more accurate use. GLONASS consisted of a full constellation of satellites with an orbital setup similar to GPS. By 2001, however,
there were only a few GLONASS satellites in operation, but Russia now has
a renewed program and more GLONASS satellites have been launched, to
possibly have a full operational constellation in the near future. In 2007,
Russia indicated that the civilian signal from GLONASS would be made freely
available for use.
Galileo is the European Union’s version of GPS, which, when completed, is projected to have a constellation of 30 satellites and operate in a
similar fashion to GPS. The first of the GIOVE (Galileo In Orbit Validation
Element) satellites was launched in 2005, and the program has continued
development from then. Galileo promises four different types of signals, including information available to civilians as well as restricted signals. Also
in development is China’s version of GPS, Compass, which is projected to
also have a full constellation of satellites. The first Compass satellite was
launched in 2007.
Other Satellite Based Augmentation Systems have been developed across
the world to act similar to WAAS but to function in other regions outside of
North America. EGNOS (European Geostationary Navigation Overlay System) is sponsored by the European Union to provide improved accuracy of
GPS throughout Europe. EGNOS functions the same way WAAS does—a series of base stations throughout Europe monitor GPS satellite data, calculate
corrections, then transmit this correction to geostationary EGNOS satellites
over Europe, and these satellites broadcast this data to Earth. An EGNOSenabled receiver is necessary to utilize this correction data, and the system
is capable of accuracies of about 1.5 meters. Another SBAS operates out of
Japan, called MSAS (Multifunctional Satellite Augmentation System), which
GLONASS the
former USSR’s (now
Russia’s) GNSS,
currently rebuilding
to a constellation of
satellites.
Galileo the European
Union’s GNSS, currently
in development.
EGNOS a Satellite
Based Augmentation
System that covers
Europe.
Compass China’s
GNSS, currently in
development.
MSAS a Satellite Based
Augmentation System
that covers Japan and
nearby regions.