Global Navigation Satellite Systems Engineering, Policy, and Design
FIGURE 1: GPS/GLONASS L1 frequency bandAs is well known, Galileo will become the European complement to the U.S. Global Positioning system.
But what about Russia’s GLONASS?
Although this constellation has been in operation for nearly three decades, the limited number of available satellites along with an uncertain governmental commitment to GLONASS performance until recent years had seriously restricted its use for aviation.
By Inside GNSS
A GNSS signal simulator is mainly used to simulate GNSS signals transmitted by navigation satellites, propagated through the Earth’s atmosphere, and received by the receiver antenna. A simulator provides a convenient signal source for the test and validation of receiver function and performance and can also be used in GNSS experiments and studies of signal/data processing algorithms.
By Inside GNSS
MD 2011 trajectory (NASA)A schoolbus-sized asteroid grazed the Earth’s atmosphere around 1:00 P.M. (EDT) on June 27. It was 7,600 miles (12,300 km) away at its closest point, at which time it veered away across the South Atlantic Ocean.
It actually passed through the GPS constellation, alerting us to the vulnerability of our vital PNT space vehicles. We can now add asteroids to the the list of GNSS collision risks that already includes other satellites and space debris.
By Inside GNSS
Detail of India’s GAGAN system, from a presentation by Dr. S.V. Kibe. For full diagram:The communications satellite that carries India’s GPS-Aided Geo Augmented Navigation (GAGAN) system has been positioned, according to major news sources in India.
"The initial phase is now over. The satellite is now in position," Airports Authority of India chairman V.P. Agarwal said at a New Delhi workshop on aviation safety.
"We are now going through the certification stage of the Satellite-Based Augmentation System (SBAS) and we will have certification of the system by June 2013." he said, according to reports.
By Inside GNSS
Washington View appears in each issue of Inside GNSS. It covers U.S. policy and program issues involving the Global Positioning System and other GNSSes. Reporting from Washington, D.C., columnist Dee Ann Divis has written about GNSS and the aerospace industry since the early 1990s in GPS World, Geo Info Systems, Jane’s International Defense Review, the Los Angeles Times, AeroSpace Daily and other publications.
By Dee Ann Divis
The Space-Based PNT National Coordination Office is located in the Dept. of Commerce Hoover BuildingRepresentatives from the Federal Aviation Administration (FAA), LightSquared, and Trimble will weigh in on the GPS vs. LightSquared interference at the afternoon session of a National Space-Based Positioning, Navigation and Timing (PNT) Advisory Board meeting tomorrow (June 9, 2011).
By Dee Ann Divis
The Federal Communications Commission (FCC) report on the level of interference between LightSquared’s proposed mobile broadband network and GPS receivers is due in a couple of weeks. Meanwhile, the fight over final approval of the system has rolled into the halls of Congress.
On Thursday (May 26) the House approved an amended 2012 Defense Authorization bill requiring the Federal Communications Commission to withhold full approval of the LightSquared 4G-LTE system and disallow operations until interference issues with military receivers are resolved.
By Dee Ann Divis
The GAGAN payload on GSAT-8 communications satellite takes off via an Airane-5 launcher on May 21 (Arianespace photo)India’s first GAGAN navigation payload on the GSAT-8 communications satellite was launched successfuly at 02:08 hrs IST on Saturday, May 21 2011, according to the Indian Satellite Research Organization (ISRO)
By Inside GNSS
After a long series of fits and starts, the Department of Homeland Security is tackling the issue of interference to the GPS signal. The agency has launched a study to assess the risks to GPS service from a variety of sources — a study that, at least on paper, will lead to a plan to mitigate interference.
Unfortunately, the effort will not directly address the one potential problem consuming the thoughts of the GPS community — widespread receiver overload from the high-powered mobile broadband service proposed by the Virginia firm LightSquared.
By Dee Ann Divis
Pace High School “Catastrophic” team, the 2010 winnerTen Lego kits transformed into autonomous robotic vehicles will gather, with their high school student masters, on Saturday, May 21 at the Smithsonian for the 2011 national championship of the Institute of Navigation Mini-Urban Challenge.
It all happens from 8 a.m. to 5 p.m. in the Spark!Lab and first floor of the Lemelson Center for the Study of Invention and Innovation on the National Mall.
By Inside GNSS
If you are lucky enough to be nine to eleven years old and living in Belgium or Bulgaria, you could get your name on one of the first European navigation satellites.
Two of them will launch from French Guiana in September 2011. Although Europe already has test satellites in the sky, these launches will mark the beginning of Galileo, a global navigation satellite system much like GPS.
Most of us who have ever gotten onto an airplane know the drill: when the doors are closed and sealed and the pilots push back from the terminal, the mobile phones are turned off — along with other portable electronic devices.
There’s a reason for that. Airline operators and the Federal Aviation Administration wish to avoid any possible interference with the aircraft’s avionics that support its navigation and communications functions.
By Dee Ann Divis
Figures 1 & 2For the complete story, including figures, graphs, and images, please download the PDF of the article, above.
Growing dependence on GNSS for positioning, navigation, and timing (PNT) has raised a parallel concern about the potential risks of signal interference. The popular press has recently highlighted accounts of car thieves using GPS jammers, solar flares pumping out L-band radiation, and faulty television sets causing havoc to GPS receivers across an entire harbor.
By Inside GNSS
