Perspectives on Global Navigation
Satellite Systems as an enabler forfuture ATM Environment
Masahiro Kudo
Electronic Navigation ResearchInstitute, JapanEIWAC 2009
Tokyo, Japan, 5-6
March, 2009

Contents• History of Aeronautical Navigation• Current situation of GNSS technology• Expectation of future GNSS environment• Discussion and conclusion

Goals• There is no question at all that in the future
GNSS will play a more important role tosupport aviation industries.
• Without the technology, new advanced ATM
could not be realized.

Origin of Position Determination• Latitude– ByBasic
measuring
the altitudeof stars( Sun,instruments
are almost
identicalto Moon,Polaris,those etc).
of GNSS– Since ancient era. Eratosthenes measured the size..Artificial stars withknown positions
rdof theglobe (B.C 3 century)..Precise clock..Global coordinates (WGS-84)• Longitude– Requires very precise clock and global
time/position reference .
– Need to wait until A.D.16-17 century– Royal Greenwich Observatory established in 1675

Navigation technologies for remoteand oceanic areas for aviation• Celestial Navigation• DC-8 used to have small windows on the ceil of thecockpit for this purpose.

• Inertial Navigation – widely used
• Doppler radars – measuring ground speed anddirections• Need to have initial positions -> KE007 case
• Accumulation of errors->For long haul flight – requirement of position update byother methods (GPS, VOR/DME)The first global radio navigation
system• OMEGA 1970’,80’s – 1997
– Receivers with automatic position calculations– Accuracy is low.
• several kilo meters depending on propagation
conditions and geometry of ground stations– Surface applications especially for vessels -> notwidely recognized as aeronautical navigation aids
– Underwater applications (i.e. Submarines )GPS as a pioneer of the new era• GPS ( 1990’s – now ) for civil use– No accumulation of errors– No need to have initial positions– Precise time base, timing synchronizations– Almost global coverage – polar regions may havepoorer DOPs.
– Sufficient accuracy over the globe for aviation withaugmentations as necessary– Vertical guidance with proper augmentations• APV-I,II, LPV200, CAT-I,II,III by GBAS

GPS vs other techniques• GPS – Celestial Navigation– No navigators necessary, accuracy, frequency ofmeasurements• GPS – OMEGA– 3D(4D) positioning, accuracy• GPS-INS/IRS– no initial position, no cumulative errors– Smoothness of tracking, polar regions

Current situation of GNSS
technologies and its services• GPS is available now.
– At least 27 satellites• Has exhibited good performances so far• Longer actual life time of satellites than designed.
• Tendency of delaying a replacement with new satellites– As of today, virtually dominating sat-nav. market.
– Besides aviation, various applications available inour daily lives
Cars, mobile-phones, securities, emergencies, science,sports, surveys, network synchronizations, etc.

Core satellite networks other thanGPS• GLONASS is available.
– Still needs to launch additional satellites for fullcapacity– Need to develop receivers especially forcommercial applications– Modernization program expected• GALILEO as a future system– Two experimental satellites in orbit– For IOC, needs to wait until around 2012

Core satellite networks other thanGPS (cont’d)• Beidou ( China )– Need to have further information about the newconstellations.

Augmentation systems• Satellite based Augmentation Systems– Operational systems – WAAS, MSAS
– Close to be operational – EGNOS, GAGAN– Compass/Beidou ?
– QZSS – R&D phaseAugmentation systems (cont’d)• Ground based Augmentation Systems– Expected certification of CAT-I GBAS groundsystem by FAA in 2009
– CAT-II,III GBAS will being developed under theinternational effort.
– Marketing strategy and attractive applications
provided by GBAS are surely needed to compete
existing Instrument Landing System.
– Requirement must be different due to regionalunique characteristics. Necessary user
involvement will resolve the specific issues.

Why GPS is so successful ?
• Stable operations since 1990’s after declaringfor civil use• Political commitments to international
communities
Many of users are satisfied• Successive policy statement through Democratic andRepublic administrations

with GPS as a whole.

• Disclosure of technical information• Specifications of Signal In Space• Other related documents• Status of operations – through USCG web siteExpectations of future GNSS
environment• Can we expect in the future that GNSS is stillavailable for users ?

• Who will provide GNSS services?
• What kind of services will be available ?

Can we expect in the future that GNSS is
still available for users ?
• GNSS will keep its momentum for certain
states to build, launch, operate and maintainthe system.
– There is a reality that space technology still has
been keeping national interests for countries since
the successful launch of the Suptnik-1 satellite 50years ago.
– It seems the situation would not be drasticallychanged during the coming 10-15 years.

• The history may not go backward after
knowing GNSS benefit.

• As a result, there is enough reason tobelieve GNSS will be available in thefuture.

Who will provide GNSS services
and why?
• Core constellations will be even provided by
few countries while technologies themselves
may be disseminated in the world.
• Competitions among core satellite networks
may occur.
– Users expect new services through thecompetitions.

What kind of services will beavailable ?
• Considering the current dominant situation by
GPS, new constellations should havemarketing strategies to compete GPS.
• Excellent new services by other satellite
networks should be required for wider useracceptance.
• Through competitions, more attractive
services may be realized.
• In this sense, involvement of users isnecessary.

Discussion and conclusion

Message from users to future
constellations• Additional capabilities will be absolutely
necessary, when compared with existingsystems.
• Disclosure and dissemination of technicalinformation will drive development of userapplications.
• Stable political commitment will brew users’
confidence to the core satellites.

For users( countries other than core satellite providers )• Need to know themselves that they are a‘follower’ by nature, e.g. more or less,dependent on GNSS policies of core satellite
providing countries.
• Understanding the context above, however, tomaximize influence to the GNSS services,
users should conduct R&D to catch up with oreven surpass them at least technicalcompetence concerned and,

For users (cont’d )• let the core satellites know the reality of theGNSS user market, resulting in more
preferable and excellent new services undercompetitive GNSS environment.

Thank you

Questions?