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GPS knocked out

Ben Longden

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April 5, 2007 - 11:28AM


The Global Positioning System (GPS), increasingly vital technology for activities including navigating cars and planes, bank financial transfers and more, may be threatened by powerful radio bursts from the sun, a panel of scientists in the US warned today.


"Our increasingly technologically dependent society is becoming increasingly vulnerable to space weather," David L. Johnson, director of the US National Weather Service, said at a briefing.


GPS receivers have become widely used in recent years, using satellite signals to navigate planes, ships and automobiles, and in the use of mobile phones, mining, surveying and many commercial applications.


Indeed, banks use the system to synchronise money transfers, "so space weather can affect all of us, right down to our wallet," said Anthea J. Coster, an atmospheric scientist at the Haystack Observatory of the Massachusetts Institute of Technology.


The cause for their concern, Johnson said, was an unexpected solar radio burst on December 6 that affected virtually every GPS receiver on the lighted half of Earth. Some receivers had a reduction in accuracy while others lost the ability to determine position, he said.


Solar activity rises and falls in 11-year cycles with the next peak expected in 2011.


If that increasing level of activity produces more such radio bursts the GPS system could be seriously affected, the researchers said.


And protecting the system is no simple task, added Paul M. Kintner Jr., a professor of electrical engineering at Cornell University, who monitored the December event.


There are two possible ways to shield the system, he said, both very expensive. Either alter all GPS antennas to screen out solar signals or replace all the GPS satellites with ones that broadcast a stronger signal.


That is why it is essential to learn more about the sun's behaviour quickly in an effort to find ways to predict such events, the researchers said.


In addition to the GPS system, the December solar flare affected satellites and induced unexpected currents in the electrical grid, Johnson said.


"The effects were more profound than we expected and more widespread than we expected," added Kintner.


Dale E. Gary, chairman of the physics department of the New Jersey Institute of Technology, said the burst produced 10 times more radio noise than any burst previously recorded.


The difference between that burst and normal solar radio emissions "was like the difference between the noise level of a normal conversation and the noise level in the front row of a rock concert," he said.


"This is a wake-up call" to improve technology, commented Anthony J. Mannucci, group supervisor at NASA's Jet Propulsion Laboratory.


Patricia H. Doherty, co-director of the Institute for Scientific Research at Boston College, said the burst affected but did not shut down the Federal Aviation Administration's Wide Area Augmentation System, which uses GPS signals to help in navigation.


Most WAAS ground stations maintained contact with enough satellites to continue working, although their accuracy was somewhat affected, she said.


The stations have to maintain contact with at least four satellites to work, but they usually monitor at least 10 to increase their accuracy, she said. Most were able to meet the minimum, she said.


The briefing came at a Space Weather Enterprise Forum convened by the National Oceanic and Atmospheric Administration to discuss the effects of solar activity. Because of its increasing importance, Johnson said, the Weather Service's Space Environment Centre was converted from a mainly research centre in 2005 to an operational centre reporting on solar activity and its impacts.




I guess this is another reason why wee need to learn the map, ruler and compass stuff backwards....:;)2:





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Dead Reckoning


Ben, useful post,


Very Interesting reading, what is most obvious here in SA, although pilots are obviously taught and practice real navigation at student level. After a year with a licence, how many can still remember dead reckoning, triangle of velocities and IFR (i follow roads). What is scary is the fact that some buy two GPS devices as 1 may pack up !! If the network fails then what ??


A few years back i flew through the Kalahari with no navaids at all other than two GPS devices, and a secondary back up using the sun..miles of nothing...


My honest belief is that principle navs should be part of a annual flight test.


Its too easy to follow the arrow..like business stops when internet stops, GSM networks crash and so on.


Is Australia the same ??


Cheers Paul



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What's this about an annual flight test?


Don't even think of it. We don't need it but if you suggest it someone may think it is necessary and then you will be pissed off as well as me.



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Some time ago I dropped a glider off near Tocumwal and flew 150km generally east to find a private strip with my GPS. Found myself musing over the uselessness of 100 Billion dollars worth of gear spinning in space and me with flat batteries. I get there IFR; I Follow Roads!!



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  • 2 weeks later...

Ladies and gents


If the Magenta Line goes AFU we are all gonna be in strife, so start looking at the map and out the windoze!


As for me....magenta line is good:clown:





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What I like about the GPS is that I can give an accurate position to other traffic, and the time to destination is good. Otherwise I stick with the map.


With a slow plane the GPS can be disconcerting when the time to destination gets longer rather thanless. Dont laugh it happened to me in a Thruster with 30knot headwinds once.



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  • 3 weeks later...

GPS are generally very reliable, the main problems with GPS is finger trouble. It's like anything, know your machine and it's capabilities. There has only been about 10 minutes in the last 10 or more years that any problems actually interfered with the signals so the units were unuseable.


Having said that you should still know how and be able to navigate by the old ways.



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