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The GPS/GNSS newsletter by NavtechGPS Inc., the GPS professional's resource since 1984. |
| April 9, 2007 |
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Editor-in-Chief:
Carolyn P. McDonald (send news items to cmcdonald@navtechgps.com)
Technical
Editor: Keith D. McDonald (satconsult@aol.com)
Production
& Design: Yelena Teterina (yteterina@navtechgps.com)
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ITEM 1) GPS
SIGNIFICANTLY IMPACTED BY POWERFUL SOLAR RADIO BURST
During an unprecedented solar eruption last December,
researchers at Cornell University confirmed solar radio bursts
can have a serious impact on the Global Positioning System (GPS)
and other communication technologies using radio waves. The
findings were announced Wednesday in Washington, D.C., at the
first Space Weather Enterprise Forum‹an assembly of academic,
government and private sector scientists focused on examining
the Earth's ever-increasing vulnerability to space weather
impacts.
Solar radio bursts begin with a solar flare that injects
high-energy electrons into the solar upper atmosphere. Radio
waves are produced which then propagate to the Earth and cover a
broad frequency range. The radio waves act as noise over these
frequencies, including those used by GPS and other navigational
systems which can degrade a signal.
NOAA, NASA and partner agencies in the National Space Weather
Program are looking to the future needs of our highly technical
society, and are anticipating seamless specification and
prediction of the atmosphere from the ground to the edges of the
Earth's magnetosphere and beyond to the Moon and Mars. The NOAA
Space Environment Center is the nation's first alert of solar
activity.
"Space weather cuts across many different federal agencies and
is a particularly fruitful area in which to develop sustained
partnerships between government agencies and academia," said
Brig. Gen. David. L. Johnson, U.S. Air Force (Ret.), director of
the NOAA National Weather Service. "We are, and will continue,
to work together to keep the public ahead of nature's storms."
Forecasters from the NOAA Space Environment Center in Boulder,
Colo., observed two powerful solar flares on December 5 and 6,
2006. These violent eruptions originated from a large sunspot
cluster identified by NOAA.
On December 6, 2006, a solar flare created an unprecedented
intense solar radio burst causing large numbers of receivers to
stop tracking the GPS signal. Using specially designed receivers
built at Cornell University as sensitive space weather monitors,
Cornell scientists were able to make the first quantitative
measurements of the effect of earlier solar radio bursts on GPS
receivers. Extrapolations from a previous moderate event led to
the prediction that larger solar radio bursts, expected during
solar maximum, would disturb GPS receiver operation for some
users.
"In December, we found the effect on GPS receivers were more
profound and wide spread than we expected," said Paul Kintner,
Ph.D., professor of electrical and computer engineering at
Cornell University. "Now we are concerned more severe
consequences will occur during the next solar maximum."
"This solar radio burst occurred during the solar minimum, yet
produced as much as 10 times more radio noise than the previous
record," said Dale Gary, Ph.D., chair and professor of the
physics department at New Jersey Institute of Technology.
"Measurements with NJIT's solar radiotelescope confirmed, at its
peak, the burst produced 20,000 times more radio emission than
the entire rest of the sun. This was enough to swamp GPS
receivers over the entire sunlit side of Earth."
The Global GPS Network, a set of precise GPS receivers used for
a variety of scientific and real-time applications, also was
affected by this solar disturbance. These applications include a
very high accuracy positioning service that can provide a user's
position with 10 to 20 cm accuracy anywhere in the world, on
land, in the air or in Earth's orbit.
"NASA wants to better understand this solar phenomenon so we can
limit the adverse impacts on real-time systems," said Tony
Mannucci, Ph.D., principal technical staff and supervisor,
Ionospheric and Atmospheric Remote Sensing Group at the NASA Jet
Propulsion Laboratory.
Additionally, researchers at Boston College found the December 6
event was the first time a solar radio burst was detected on the
civil air navigation system, Wide Area Augmentation System, or
WAAS.
"Although our findings indicate the effects of this solar burst
were less intense on WAAS than on other operational systems,
mainly due to the robust system design, it is important for us
to consider the potential impact of future, more powerful, solar
radio bursts during periods of high solar activity," said
Patricia Doherty, co-director and senior scientist, Institute
for Scientific Research at Boston College.
There are three key points to remember about solar radio bursts.
"First, society cannot become overly reliant on technology
without an awareness and understanding of the effects of future
space weather disruptions," said Anthea Coster, Ph.D., MIT
Haystack Observatory. Second, the December 6 event dramatically
shows the effect of solar radio bursts is global and
instantaneous. "Third, and equally important, the size and
timing of this burst were completely unexpected and the largest
ever detected. We do not know how often we can expect solar
radio bursts of this size or even larger."
NOAA, an agency of the U.S. Commerce Department, is celebrating
200 years of science and service to the nation. From the
establishment of the Survey of the Coast in 1807 by Thomas
Jefferson to the formation of the Weather Bureau and the
Commission of Fish and Fisheries in the 1870s, much of America's
scientific heritage is rooted in NOAA. NOAA is dedicated to
enhancing economic security and national safety through the
prediction and research of weather and climate-related events
and information service delivery for transportation, and by
providing environmental stewardship of the nation's coastal and
marine resources. Through the emerging Global Earth Observation
System of Systems (GEOSS), NOAA is working with its federal
partners, more than 60 countries and the European Commission to
develop a global monitoring network that is as integrated as the
planet it observes, predicts and protects.
More info:
http://spaceflightnow.com/news/n0704/04gpssun/
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ITEM 2) TECHNICAL
TUTORIALS PRIOR TO ION GNSS 2007
REGISTER NOW FOR NAVTECH'S 2007 TUTORIALS!
- EARLY BIRD DISCOUNT DEADLINE AUGUST 24
- MAKE HOTEL RESERVATIONS AS SOON AS POSSIBLE FOR SPECIAL RATES
Browse our 32 technical tutorials to be held September 24-25 in
Fort Worth, Texas prior to the ION GNSS 2007 Conference:
http://www.navtechgps.com/seminars/GPStutorials/iongnss2007.asp
Register for tutorials on-line at:
http://www.navtechgps.com/seminars/GPStutorials/tutreg.asp
(Register on or before August 24th for an early bird discount!)
Make Your Hotel Reservations Online as soon as possible for
special ION rates at:
http://www.ion.org/meetings/gnss2007hotel.cfm
Separate online registration for the ION GNSS 2007 conference
will be available soon at:
http://www.ion.org/registration/
** Please note that NavtechGPS and the ION are different
organizations.
This is the world's largest GPS meeting, with the largest
exhibit. Be there for product announcements, leading edge
technical papers
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
ITEM 3) MAY COURSES IN NOORDWIJK, NETHERLANDS
NavtechGPS will hold GNSS courses on May 21-25, 2007 at
ESA-ESTEC facility in Noordwijk, The Netherlands.
The following courses will be offered:
Course 359A: Fundamentals of GNSS (Day 1 of Course 359),
May 21, 2007
Instructor: Mr. Keith McDonald
http://www.navtechgps.com/seminars/GPScourses/sem359.asp#359A
Course 359B: GNSS Signals and Receiver Operations
(Days 2-3 of Course 359), May 22-23, 2007
http://www.navtechgps.com/seminars/GPScourses/sem359.asp#359B
Instructor: Dr. Chris Hegarty
Course 359C: Galileo Design, Development and Signal
Processing
(Days 4-5 of Course 359), May 24-25, 2007
Instructors: Mr. Marco Falcone, Dr. Jörg Hahn, Mr. T. Burger,
Dr. M. Hollreiser
http://www.navtechgps.com/seminars/GPScourses/sem359.asp#359C
Course 359: GNSS Operation for Engineers and Technical
Professionals
(The full 5-day course), May 21-25, 2007
Instructors: Mr. Keith McDonald, Dr. Chris Hegarty, Mr. Marco
Falcone, Dr. Jörg Hahn, Mr. Thomas Burger, Dr. Martin Hollreiser
http://www.navtechgps.com/seminars/GPScourses/sem359.asp
Course 448: Advanced Receiver Processing of GNSS Signals
(May 21-24, 2007)
Instructor: Dr. John Betz
http://www.navtechgps.com/seminars/GPScourses/sem448.asp
For complete information, please visit
http://www.navtechgps.com/seminars/sem2007schedule.asp#0704_ESA
Online registration is now available at:
http://www.navtechgps.com/seminars/semreg.asp
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
ITEM 4) JUNE COURSES
IN ORLANDO, FLORIDA
Sheraton Safari Hotel
Orlando, Florida
(NOTE: book your hotel room by May
14th and ask for NavtechGPS room-block to get our special rates)
356: "GPS Operation for Engineers and Technical
Professionals", taught by
Mr. Keith McDonald and Dr. Chris Hegarty (June 4-8, 2007)
http://www.navtechgps.com/seminars/GPScourses/sem356.asp
About this course:
- To give a comprehensive introduction to GPS and DGPS
technology, system concepts, design, operation, implementation
and applications.
- To provide detailed information on the GPS signal, its
processing by the receiver, and the techniques by which GPS
obtains position, velocity and time.
- To present current information on the status, plans, schedule
and capabilities for GPS, as well as for other satellite-based
systems with position determination applications.
- To fill in technical information gaps for those working in
GPS.
Who should attend:
Excellent for engineering staff who need to be rapidly brought
up to speed on GPS, and for those already working in GPS who
need exposure to the system as a whole, in order to work more
effectively.
111: "GPS Fundamentals",
taught by Mr. Keith McDonald (June 4, 2007)(same as Day 1 of
Course 356)
http://www.navtechgps.com/seminars/GPScourses/sem111.asp
122: "GPS Fundamentals and Enhancements",
taught by Mr. McDonald (June 4-5, 2007)(same as Days 1-2 of
Course 356)
http://www.navtechgps.com/seminars/GPScourses/sem122.asp
217: "Introduction to Differential GPS",
taught by Dr. Chris Hegarty (June 6, 2007)(same as Day 3 of
Course 356)
http://www.navtechgps.com/seminars/GPScourses/sem217.asp
356B: "GPS Operations: DGPS, GPS Signals & Processing",
taught by Dr. Chris Hegarty (June 6-8, 2007) (The first day,
Wednesday, is the same as 217)
http://www.navtechgps.com/seminars/GPScourses/sem356.asp#356B
================================================
447: Applied Kalman Filtering (4.5 days)
Dr. Larry Levy (June 4-8, 2007)
http://www.navtechgps.com/seminars/GPScourses/sem447.asp
About this course:
This course is a highly intensive short course on Kalman
filtering and Kalman filtering applications. Emphasis in the
course is on practical applications, but sufficient supporting
theory is provided to give attendees the necessary tools for
meaningful research and development work in the field.
Considerable time is devoted to modeling, the most difficult
aspect of Kalman filtering, in an application setting.
There will be a high level of instructor/attendee interaction,
designed to provide hands-on problem solving and solution
discussions. The learning experience will also be supplemented
by homework assignments to assist attendees in improving their
understanding of course concepts.
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
ITEM 5) NEWSLETTER
LINKS and USEFUL WEBSITES (This is an archival
list. Please notify us if your own link changes.)
* Mr. Glen Gibbons, founding editor of "GPS World", launched a
new international trade journal, "Inside GNSS" last January.
Subscription is FREE and details can be found at
http://www.insidegnss.com
* The European Space Agency publishes an EGNOS newsletter that
is called EGNOS NEWS, focusing both on EGNOS and on satellite
navigation issues:
http://ravel.esrin.esa.int/docs/egnos/estb/newsletter.htm
* To view details on "GPS World" magazine, the GPS standard
since 1990, go to
http://www.gpsworld.com/gpsworld
* For the archives of the Locus Inc. newsletter on LORAN
positioning and timing, go to:
http://www.locusinc.com/loran_newsletter.html
* For the newsletter published by "Professional Surveyor"
Magazine, go to
http://www.profsurv.com/newpsm/news.php
* Continuously updated newsletter by the US Coast Guard's
Navigation Center "NAVCEN" is at
http://www.navcen.uscg.gov/
* Military and Aerospace magazine's newsletter is found at:
http://mae.pennnet.com/Search/index.cfm?Section=Archives
* Kalman filter site maintained by Gregory F. Welch, UNC, Chapel
Hill, NC is at
http://www.cs.unc.edu/~welch/kalman/
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
ITEM 6) MEETINGS
CALENDAR
______________________________________
April 23-25, 2007
63rd Annual Meeting
with Bio-Nav and Classified Sessions
Royal Sonesta Hotel
Cambridge, Massachusetts
www.ion.org
______________________________________
September 25-28, 2007 (NavtechGPS Tutorials: September 24-25)
ION GNSS 2007
Fort Worth Convention Center
Fort Worth, Texas
www.ion.org
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Carolyn McDonald, Editor
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