Last week we saw how a GPS misused could cause a fiery frig up, but can giant fiery explosions on the Sun frig up the whole GPS system? I first heard about this thanks to a small article in the February issue of Soundings. It’s not online, but the research and incidents it discusses are. The phenomenon of flare-induced radio wave bursts interfering with relatively weak GPS signals was perhaps first observed in Sept. 2005, as reported by two Cornell U. researchers a year later. Shortly thereafter—on Dec. 5, 2006–the huge flare seen above caused a burst powerful enough to “swamp GPS receivers over the entire sunlit side of Earth” the next day, according to a scientist quoted by NOAA magazine. Now, it’s not clear to me how many civilians suffered noticeable GPS glitches on that day, or for how long, but I can tell that I first had my ear bent about the need for a secondary electronic positioning system back 2001, which led to this PMY column. The obvious choice seems to be Loran, but apparently our government is still thinking about it. (Let’s hope Class B AIS approval doesn’t take so long!) At any rate, when headed out to sea you might want to check space weather as well as the ocean variety, and of course don’t rely on any one stream of nav data.
Working with a Dynamic Positioning system aboard my ship makes GPS critically inmportant. While we have advance (expensive!) differential systems we still suffer signal loss due to this problem about once every few months. To help pro-mariners gCaptain put together some tools for monitoring GPS systems. They are actually just links to the resources on the web (including space weather) that we use on a daily basis. They can be found under the "electronic navigation" and weather links here: Marine Tools & Links
Before you leave that page, click on the tab entitled GPS Interference Notices. This downloads a PDF file. Look at it. Today's file shows:
GPS interference is being tested Jan 08 through Mar 08
Anybody know of a more modern Loran Rx than Ben talked about in his 2002 article?
Posted by: Joh Foster at January 15, 2008 11:38 AM
I've just figured it out, Ben: you do not sleep. Thats how you can keep up with so many different sources.
SI-TEX has a loran receiver that speaks NMEA 183 and N2K. I've asked Garmin if it can be used for posiioning in the event of a Solar event, but the response from the second shift at Garmin was a little sleep-impaired. They need your secret. Lets see if Smart Radio has an economical solution!
eLoran - the latest on eLoran in the ION newsletter (Institute On Navigation) said that eLoran is getting the go-ahead and that the current wide-deployment differential GPS infrastructure will be cut-back to only the USCG-run differential sites for purposes of coastal and harbor navigation. The curious part of this is that the continental DGPS infrastructure has been adopted for precision train control (running freight trains with much smaller headways) and that Dept. of Transportation may chose to keep the cDGPS system running for a while. As usual,
"It's not done until it's not undone."
cheers,
-mo
Posted by: Mike at January 16, 2008 8:37 PM
You should broaden your bookshelf to include National Fisherman and others. I wrote about this in 1999 for NF.
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