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Hardware

GPS Rollover Tonight 71

Posted by Hemos from the fun-with-time-date-stamps dept.
A reader wrote to us with the reminder about the GPS rollover tonight. It will occur at midnight, UTC time. Most machines should be compliant, but check out The Coast Guard for more information. Essentiallly, they are rolling over the GPS time, and machines that aren't repaired/replaced will claim that it is 6 Jan 1980, and August 23 will be Jan 7, and so on.
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GPS Rollover Tonight More

GPS Rollover Tonight

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  • The FAA has not approved GPS units as a primary navigation instrument. Almost all planes use LORAN (Same idea, only the transmitters are ground based -- cheaper, more accurate, but not very useful if you aren't airborne). I don't know if that has any sort of rollover problems, though.
  • isn't that the rational behind a lot of Y2K problems?
    "Oh, we know it exists, but by the time it really happens,
    somebody else will have replaced all this old equipment."

  • GPS/NDS (Score:1)

    by thor ( 3901 )
    brings back memories from my CSOC days...

    "golf ball" & r2d2 antennas - hp1000 .vs. sun 3/260's & 280's - GPIB

    daily briefings with tight ass generals (lol) - working 11pm-7am - 1lt apodoca

    tracking lightning strikes for NOAA

    the look on some cpt/col's face when a lowly a1c tells them their bird is wobbling - priceless

    the good ole days...

    as i was
    thor
  • First, as some people noted, it's Saturday night.

    I'm really tempted to be at a sporting goods/hardware store that sells GPS receivers, and be "looking at buying" a couple at 6 PM MDT tomorrow night (MDT = GMT -0600).


  • Yes, but there were a lot fewer planes in the air too. :-)

    On the other hand, other posters in this thread and elsewhere have pointed out that essentially no commercial airliners are relying on GPS.

    So, if you must worry about flying on a commercial airliner, worry about some bozo with a haywire GPS blundering in front of your plane, not about your plane's own navigation. (And even that probably should be regarded as paranoia...)

  • Gonna have to turn mine on and check it out... I wanna see what happens.

    Malto
  • GPS rollover is tomorrow night (between Saturday and Sunday).
  • Because of all the Y2K hysteria, at least something like this WILL be paid attention to. Instead of dismissing it as "Oh, so it'll show the wrong date, who cares?" some GPS-system owners may actually take this warning seriously and get their units checked out, or be sure to NOT be out navigating at midnight GMT Saturday. So in a weird, roundabout way, the Y2K hysteria may actually end up saving a few lives...
    -----
  • Worst thing that could possibly happen with the GPS rollover... The classic Y2K misnomer: A plane falls out of the sky.

    I don't think it would matter if it was a technicality (really bad weather, etc). The millenial panic level (which seems a bit subdued to me so far) would take a big jump, regardless of the fact that GPS and Y2K are completely seperate problems.

    I also don't see too many people stocking up on compasses and sextants...
  • Argh. I guess I just repeated the link at in the story, but my point was the link cleary states that the rollever happens on 21-22 August, not 20-21 August.
  • More importantly that the date being wrong, the date is an essential part of the calculation which works out where you are. If the system isn't looking up the almanac for the correct date, it's not going to give you the correct location.

    "Accuracy of navigation may also be severely affected" is an understatement. There will be no accuracy at all.

  • I'm flying on Southwest at 0800 Eastern Standard Time (GMT + 0500?) Sunday morning.

    Not to be paranoid, but do I have anything to worry about? It's a transcontinental flight, so they can't use Loran. Obviously, this is not a surprise to those in the aviation business, but I still worry a teeny bit flying on a cut-price carrier...

    Bravery, Kindness, Clarity, Honesty, Compassion, Generosity

  • I wouldn't worry. What's the worst that can happen? :)

  • Subject says it. The GPS EOW rollover happens midnight UTC, tomorrow - not tonight. More info here. [uscg.mil]

  • GMT+5h? Don't worry, if it's an issue, they'll see it first and the plane won't even be allowed off the ground...
  • Which is more aesthetically pleasing; calling it a W2**10 bug or W2^10 bug? Or W1K bug, perhaps? Or Just WK?
    A while ago I attempted a humourous web page, part of which enumerated [irelands-web.ie] some of the ways that tech was going wrong; I was surprised that my research research dug up so many ways that technology we relied on is fundamentally flawed. It seems that there isn't a technology out there that doesn't feature a fatal flaw that'll kill us all a few years hence.
    It's got to the stage where I'm thinking of heading for the hills not because of Y2K, but because sooner or later something electronic is going to kill us all.
  • wow! why didnt we see this coming!! where are all the gps bug programmers being hired and making small fourtunes when you need them!! this is in a way a good indicator on how much hype the y2k bug got versus this bug. now i know that the scope and affected areas is totally different, but it still is something to think about when it comes to pop computer culture (i hope your listening wired magasine and zdtv) and other various forms of sensationalist computer media (press coverage, not software)
  • Think of it like Groundhog's Day: If some GPS systems fail and there's a catastrophy, we'll have a bad Y2k, if nothing happens we'll have a good one.
  • It shouldn't be a concern. When the FAA Ok'd GPS for IFR equipment, part of the testing that GPS manufacturers had to perform was for proper handling of the EOW rollover. And there are only a handful of IFR certified aircraft that use GPS as the only means of radionavigation, and I don't think that there are any in commercial service. Your airliner will most likely be using standard VOR/DME (VHF omnidirectional radio/distance measuring equipment) for navigation, and GPS only as a backup.
  • heheh! Ain't that the truth. ;-)

    (nice tag line btw)
  • The wording was kind of confusing on that page, but I thought that the GPS rollover (the modulo 1024 week field) was in the specs for the GPS system, and that if the receiver designers "cut the corners" and ignored this issue, it was their fault/problem.

    I also read a while back that the biggest problem with this rollover would maybe cause problems in international banking due to the fact that some international banks use the GPS timestamp to coordinate electronic transfers. Sorry I don't have the references to these...

    A
  • Uh, get a lot of timepieces and hope one of them doesn't fail?

    Well, you could do some complicated constructions with an astrolabe, a compass, and a really big chart of magnetic declinations. It'd probably be easier to reinvent electricity, though.
    --
  • http://www.cnn.com/TECH/computing/9908/20/internet .theft/

    We appreciate the news but...

    you could have kept the message shorter, still got your message across, and not crossed the annoyance threshold.

    Take it easy, news of this type will circulate very quickly.

    -matt
  • (to quote a good friend)

    The FAA *has* approved GPS as primary navigation for enroute and non-precision approach. However, the testing for that FAA approval included proving that the unit could handle GPS_Week rollover.

    But most planes don't use GPS or Loran for IFR navigation - they use ground based VOR navigation aids. So you don't have to know the latitude and longitude (as another person in this thread asked), you just follow the beam.
  • You DON'T.

    That's what had naval navigation messed up for so long. It took the invention of a really good watch, a small pocketwatch, actually, to finally get accurate longitude.

    This first watch used for such a purpose managed to make a transatlatic crossing while only loosing two seconds of time. Try taking a pendulum watch on a boat while the boat is rocking back and forth enough to make even the hardiest sailors ill...

    Those first pocketwatches must have been the cell phones of the day. They were years ahead of their time, packed so much technology into such a little bundle, looked really cool and everyone had to have one.

  • Garmin (Score:1)

    by quadra ( 2289 )
    Garmin.. one of the larger GPS makers claims all their GPSs will be ok. Some models may need to scan the sky again.. and a few need some software fixes.. overall not much to worry about.
  • I was at the train station today after work, and one of the boards was blinking "RTC failed, system rebooting"... Naturally, i assumed it was linked to the GPS satelites in some way... now that it seems that the rollover doesn't happen til tomorrow, I'm thinking that the train authority switched their systems to NT or something...
  • Most GPS units sold in past 3 or 4 years should be compliant. My Garmin GPS III is compliant (according to Garmin anyway) BTW its a nifty little nerd-toy complete with a scrolling zoomable map of the world with all of the major roads in the US on it, trip computer, compass (only works if you're moving), distance and heading to way points etc.

    It will be interesting to see if the effect of the roll over is less than or greater than what is expected. If most newer GPS units are compliant as is claimed, and the negative effects are minimal, maybe the y2K compliance/impact predictions will also be accurate. We shall see.
  • I was going to try to go hit a few, but with the GPS Rollover, I'll lose the ability to track those lil buggers as I shank em off to the right :)
    yeah OK -1 me allready
  • Probably about as accurate too...

    The GPS rollover is more likely to be the Y2K disaster scenario that your local newspaper is freaking out about. Navigation systems, electrical devices going nuts, etc.

    I think Y2K will be more of an economic problem than an "elevators will get stuck". Programmed in a thousand different ways by a million programmers, the effects will be far more random and unknown. Probably enough to shake the JIT shipping philosophy up a bit.

    OK, enough Y2K rant. All the people who've heard enough already can just go on being happy and keep their money in mutual funds before the Great Crash... ;)
  • Well, most GPS systems were designed with this and other roll-overs in mind, and chances are very slim that they will fail. Also, you still have map and compass, gyroscope, and radio to fall back on.

    Believe it or not, airlines actually flew without falling out of the sky before GPS. :)
  • Sprint PCS just went out for me in the Boston area. You gotta be shittin' me...
    --
    Kyle R. Rose, MIT LCS
  • "This means that the week count will roll over 7168/365.25 = 19.6249 years from then, or in 1980+19.625 = 1999.638 (August 21, 1999)."

    Ok, by my reasoning:

    1980
    + 19.625
    ---------
    1999.625

    Where does 1999.638 come from?

    Mycroft
  • Navigation of an aircraft can use any of a number of methods. If the GPS on board an aircraft goes out for the EoW rollover, these other methods are still available to the pilot, who will continue to fly the plane without GPS...
    • Follow landmarks on an aviation map. (Ever heard the saying "I follow roads?" That's not what IFR stands for. :-)
    • Fly a compass heading with a wind correction angle.
    • Tune in a "non-directional beacon" (NDB) radio transmitter and use direction-finding equipment in the aircraft to measure the relative direction from the plane to it. (It's old but it still works.) These transmitters are on the maps.
    • Tune in a "VHF Omnidirectional Range" (VOR) radio transmitter and use a VOR receiver in the plane to measure the compass direction from the station to the plane. (Almost every US aircraft has at least one VOR receiver.) These transmitters are on the maps too.
    • Receive signals from LORAN ("Long Range navigation") transmitters. This is as good as GPS when the upper-atmospheric conditions are good to bounce the signals long distances to you. (It propagates like a shortwave or HF Ham Radio.)
    • Ask for vectors (headings to fly from your current position) from air traffic control.
    In other words... If the GPS fails, the pilot will keep flying the plane just like before there was GPS (which wasn't that long ago.) At the very worst, someone somewhere might get lost and land at the nearest/wrong airport.

    If you want to know more about this, stop by your nearest General Aviation airport and ask a flight instructor. Depending on the airport, they can probably arrange to take you on an inexpensive introductory flight or flying lesson, just so you can see what it's like to fly an airplane. Some people get hooked after one time taking the controls...

    (Yes, I'm a Private Pilot.)

  • You enumerated a few, the ones I've heard most about; but these and many, many (, many, many) more are listed on J.R. Stockton's ``Critical Dates [demon.co.uk]'' site... all sorts of critical dates, mostly relating to rollover dates of various sorts, and mostly clustering around this era (of course). He appears to have updated it just this week, too.

  • Actually, the 15 minutes to reload the almanac isn't a limitation of the GPS, it's a limitation of the satellites. The entire almanac is only broadcast in little packets that take 15 minutes to download the whole thing.
  • In comercial airlines they normaly use another sytem for navigation called inertial navigation system. Mainly this systems is used for long range fights as the ones done over the Atlantic ocean. Normally all the aircrafts prepared for long range flights use GPS and the Inertial navigation System. This system is compose by a inercial platform, tree acelerometers and one real time integration system which calculates the real aircraft position.
  • I heard the fellow interviewed on CBC Radio's [radio.cbc.ca] As It Happens [radio.cbc.ca] program. He said that he already had a modern pc, but that he used the Altair for a lot of boilerplate legal forms that would have taken him too much time to convert to a modern program. Since the Altair was working satisfactorily, there was no reason to take the trouble to port the stuff over. With this new computer from Dell, he says he now has too many computers.
  • Was it just my GPS.. or did the week actually roll over to 0 a few seconds before the clock hit midnight?
  • Being a former employee of a major GPS manufacturer (I won't say which one...just that I got laid off because they were seriously in debt), I can tell you that the GPS design community is well aware of the week rollover problem. The problem isn't inherent in the GPS system itself, but rather in the specific units. The ground segment has the responsibility for handling local time....it doesn't really matter to the computation of satellite position. Some early units simply don't account for the rollover, so it's going to take them a while to figure out where they are.

    Two good links about this:

    http://joe.mehaffey.com/y2000dat.htm [mehaffey.com]
    http://joe.mehaffey.com/y2k-sv.txt [mehaffey.com]

  • Unless the GPS is particularly dumb, the only thing that should be affected by the rollover is that old, cheap units won't be able to use their internal almanac and the approximate date and location to quickly scan for the satellites. The date and location will be correct, but the birds won't be in the same position as they were 2^10 weeks ago.

    Instead, they'll have to scan the entire sky for GPS signals and I'll reacquire my position after 20 minutes or so. I then need to leave the GPS running for a while so (pieces of) the new almanac can be downloaded; IIRC it's included in a low-bandwidth data channel. Or I can simply download the new almanac via a free program and a non-free PC/GPS cable. (I've ordered the cable, but with my luck they may be out of stock. :-)

    Aviation and marine units, unlike hiking units, usually have far better antennas and they should be able to perform a "where in the heck am I?!" search much faster. Aviation units, in particular, will already be updated since they must periodically load new aviation databases containing the location of airports, VORs, etc.
  • Southwest has the best safety record of any airline, last time I checked.
  • It's actually in the specs...part of the original military design and intent. Newer systems were suppossed to be in place by now.....
  • Well, the missing .013 comes from the fact that GPS time "began" on January 6 1980, not January 1. So, Their math is correct, but they should have noted it as

    1980.013
    +19.625
    --------
    1999.638

  • Umm... No. GPS Week 0 started 7 January 1980, not 1 January 1980. That's where the extra comes from.

  • hey, don't go getting all paranoid now!! Sure we can't handle the tech' stuff we have and sure more and more of it is being developed daily, with little or no controls in place to monitor its effects on people and the environment. Why should that bother anyone? Physical life is just an pause in the true dance anyways. I say, bring on the chaos!!

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