Future Augmented
March 1, 2010
By: Juan Blanch, Per Enge, Todd Walter
GPS World
Coverage Improvement for Dual-Frequency SBAS
http://www.gpsworld.com/gnss-system/...d-9606?print=1

After reviewing current performance of WAAS, EGNOS, and MSAS, the
authors present expected future performance, including the benefits of
GPS L5. They evaluate the impact of the Indian GAGAN and Russian SDCM
systems on global coverage and examine southward expansions for the
original three SBASs. Finally, a look at the impact of a second
constellation of navigation satellites and the performance for a user
taking advantage of two core constellations.


The Wide Area Augmentation System (WAAS) monitors GPS and provides both
differential corrections to improve accuracy and associated confidence
bounds to assure integrity. The first satellite-based augmentation
system (SBAS), it was commissioned for service in 2003. Japan’s
MTSAT-based Satellite Augmentation System (MSAS) was commissioned in
2007, and the European Geostationary Navigation Overlay Service (EGNOS)
was declared operational in 2009, with safety-of-life service
commissioning expected in mid-2010. Two other SBASs are in the
developmental stage: India’s GPS Aided Geo Augmented Navigation (GAGAN)
and Russia’s System for Differential Corrections and Monitoring (SDCM)
have fielded equipment and plan to become operational in the next few years.

Coming improvements will expand SBAS coverage areas and strengthen their
performance. In the near term, these include more monitoring stations
and algorithmic enhancements, with incorporation of a second civil
signal in a protected aeronautical band and new GNSS constellations in
the long term.

See:
http://www.gpsworld.com/gnss-system/...d-9606?print=1