Ionospheric Interference With GPS Signals 127
Roland Piquepaille writes "In recent years, we have become increasingly dependent on applications using the Global Positioning System, such as railway control, highway traffic management, emergency response, and commercial aviation. But the American Geophysical Union warns us that we can't always trust our GPS gadgets because 'electrical activity in the... ionosphere can tamper with signals from GPS satellites.' However, new research studies are under way and 'may lead to regional predictions of reduced GPS reliability and accuracy.'" Roland's blog has useful links and a summary of a free introduction, up at the AGU site, to a special edition of the journal Space Weather with seven articles (not free) regarding ionospheric effects on GPS.
Re:GPS is digital! (Score:4, Insightful)
Re:Dual Frequency (Score:2, Insightful)
Ionosphere interference is reduced by using two frequencies. The higher frequency shifts less when it enters the ionosphere. Both frequencies are compared by the receiver, and a correction applied.
Re:Good Grief! (Score:3, Insightful)
I don't like him becasue he plagiarises stories from other sites, copies them to his blog, then submits to Slashdot. He's just trying, and succeeding, in pumping up his pagerank. Originally he used to ONLY link to his blog. There were many complaints about that, eventually he started also giving the original link, but he always adds his blog link as well. He's a parasite.
No Problems for me... (Score:4, Insightful)
Doesn't cause any problems for me. Sometimes I've got just a few feet of accuracy in my position, other times it's 10's of feet. I guess it would cause issues with my home-made cruise missle, though...
Aviation has used VOR navigation for decades, developed during WWII. And the US Government has a big OFF switch for that, too. Part of pilot training is knowing how to navigate when all the fancy gadgets are offline. Because you never know when a system will fail.
I just view this as a confirmation of what I've noticed before: that sometimes the signals aren't as good as others. Fortunately, I have a computer that is capable of recognizing the situation and performing the necessary error correction on the fly. I call it my brain.
Hence WAAS (Score:3, Insightful)
In geocaching, the greater the accuracy the better. For car navigation, you don't even need it, as the accuracy is better than the width of a road regardless!
This article seems to be a decade behind... -Randy