Future of GPS
New Applications
• Intelligent Vehicle/Highway Systems (IVHS)
• Intelligent Transportation Systems
• Automated Construction Equipment
• Time Determination/Time Transfer
• Atmospheric Sensing
• Aircraft Navigation and Landing
GPS Modernization
• New Block IIF scheduled to be launched in
next few years (2007?)
– Ability to transmit data between satellites
– Autonomous navigation
• Navigation accuracy maintained for six months (????)
• Uplink jamming less of a concern
• One upload per spacecraft per month (??)
• Minimize ground tracking
• Improved navigation
Augmented Signal Structure
• SA is now off and likely to stay off
• Additional L5 carrier frequency
– Ability to correct for ionospheric effects when
using carrier phase
– Modulated by a new civil code (similar to P-code)
– L2-L5 produces extra wide lane
– L1-L5 can be used as ionosphere free
• Military Y-code replaced by split M-code
GPS Augmentation
• Want to use GPS for aviation
– Reliability needs to be extremely good
– Want to augment GPS to provide additional
reliability and improve results
• Local Area Augmentation Systems (LAAS)
will use pseudolites
– Should allow precision approach and landing
• Category II/III
GPS Augmentation
• Can also use geostationary satellites
– Will have broadcast capability
– Transmit DGPS corrections and integrity
messages
• Wide Area Augmentation System (WAAS)
will use Inmarsats to augment GPS
– Operational sometime
GNSS
• Global Navigation Satellite System (GNSS)
• Integration of different satellite navigation
systems
– Already have capability of combining
information from GPS and GLONASS
– Also includes augmentation from other kinds of
satellites (like Inmarsat)
– Also include Galileo when launched
GNSS/LORAN-C
• Long Range Radio Navigation (LORAN)
– Used mostly for maritime navigation
– Broadcast stations organized into ‘chains’
– Very similar to GPS
• cannot provide vertical component
– Can be used to augment GPS
Hardware
• In short, hardware will continue to get
better, cheaper, smaller
– Cost will drop if quantities increase in a way
that everyone has (at least) one GPS receiver
working in his/her life
– Resolution of wave will improve (<0.1%)
– More channels (for increased number of
observables)
• More frequencies and more satellites
Software
• In short, software will continue to get more
sophisticated and run faster
– Improved modeling or solution for unknown
parameters
– Better algorithms for solution
– Faster computers will allow more to be done in
the same amount of time
GPS Products
• Data will continue to improve
– Centimeter level orbits will be available
– Centimeter level positioning will be possible in
real time
– Sub-centimeter positioning will be possible by
post-processing