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GPS Accuracy Could Start Dropping In 2010

adamengst writes "A US Government Accountability Office report raises concerns about the Air Force's ability to modernize and maintain the constellation of satellites necessary to provide GPS services to military and civilian users. TidBITS looks at the situation and possible solutions."

30 of 210 comments (clear)

  1. Where's Waldo? by Anonymous Coward · · Score: 5, Funny

    There he is! No, wait...

  2. How about cutting the dead wood? by mr_stinky_britches · · Score: 4, Insightful
    From TFA:

    The GAO's report draws attention to problems that the Air Force has had in working with contractors to build and launch GPS satellites within cost and schedule goals. Some of the problems stem from government acquisition methods that didn't provide for enough oversight, and added requirements that resulted in cost and schedule overruns.

    Sounds like a software/project management issue to me. I didn't finish reading the article, but I hope one of their proposed solutions was to fire the incompetent people who can't deliver on-time or within budget.

    just my .02c

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    1. Re:How about cutting the dead wood? by FireFlie · · Score: 5, Insightful

      Just your 1/50th of a cent?

    2. Re:How about cutting the dead wood? by Anonymous Coward · · Score: 5, Funny

      .02Vc (Verizon cents)

    3. Re:How about cutting the dead wood? by jeepien · · Score: 5, Funny

      Well, that wasn't really a cent sign. He might have meant it was just his 5 995 849.16 m/s.

  3. Just in time for Galileo by MichaelSmith · · Score: 4, Insightful

    Best not to rely entirely on one system anyway.

    1. Re:Just in time for Galileo by Anonymous Coward · · Score: 5, Funny

      I'm Catholic you insensitive clod! I can't use it!

    2. Re:Just in time for Galileo by Repton · · Score: 5, Funny

      Heh. Naming a bunch of things that orbit the earth after Galileo. Irony :-)

      --
      Repton.
      They say that only an experienced wizard can do the tengu shuffle.
  4. How much is actually going to be lost? by Chmcginn · · Score: 5, Insightful
    With one or two satellites below the 24 constellation, the accuracy isn't going to be impeded any noticeable amount. Any GPS reciever that can take DGPS signals might well not even notice.

    The real concern is a major solar event - if they're having a big issue replacing one every other year, imagine if a major solar storm took out a dozen at once.

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    1. Re:How much is actually going to be lost? by Shadow+of+Eternity · · Score: 4, Funny

      Maybe people will stop looking at me funny when I carry a compass everywhere.

      Maybe they'll stop looking at me even stranger when I tell them which way is north WITHOUT a compass.

      --
      A bullet may have your name on it but splash damage is addressed "To whom it may concern."
    2. Re:How much is actually going to be lost? by master5o1 · · Score: 5, Funny

      You must be using your computer wrong.

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      signature is pants
    3. Re:How much is actually going to be lost? by evangellydonut · · Score: 5, Informative

      solar event will cause transient events that will recover in a few seconds.

      GPS2F was awarded in the early 90s with a launch date of more than 10 years out. This caused parts issues that significantly magnified design issues. Without going into company secrets, let's just say that bean-counters and engineers fought long and hard. I wonder why Boeing lost GPS3...

      If LockMart can't deliver as promised, Airforce can always buy more IIF. After 12-or-so builds currently on contract by Boeing, you figure even the incompetent can get their bugs worked out by then (sans part issues)

    4. Re:How much is actually going to be lost? by The+Archon+V2.0 · · Score: 5, Funny

      Maybe people will stop looking at me funny when I carry a compass everywhere.

      People used to do the same to me. When someone does, I stab them with the pointy end and draw a circle on their face.

      Now they don't look at me funny.

    5. Re:How much is actually going to be lost? by tompaulco · · Score: 4, Funny

      Maybe they'll stop looking at me even stranger when I tell them which way is north WITHOUT a compass.
      Telling North is pretty easy using the stars if available at night or the sun if you are reasonably sure of the season and approximately what time of day it is.
      As for the old boyscout adage, I think it should be changed to "Moss always grows on the outside of the tree", that's how useful it is. And of course, a rolling stone gathers no moss, so no matter which way it is rolling, that is no indication of which way is north.
      If you are ever going hiking and want to be sure not to get lost, be sure to pack your fiberoptic cable and a shovel. If you get well and truly lost, dig a trench and bury the cable. When the backhoe comes to dig it up, simply follow the backhoe back to civilization.

      --
      If you are not allowed to question your government then the government has answered your question.
  5. Surveyors are going to start having problems... by yourassOA · · Score: 5, Interesting

    with land disputes. "Your fence is on my property" etc. We have had problems as it is with surveys in the last couple of years. It was blamed on poorly trained surveyors and some instances issues were settled in court particularly over contradicting reports and who pays for the cost of the surveys. In one instance 1/4 mile of new fence had to be moved at a cost of $10,000 and lawyer/surveyor fees of $25,000 over the fence been 5 feet out. The land in question later was sold for $60,000. What a waste of money over a silly pissing contest.

    1. Re:Surveyors are going to start having problems... by rir · · Score: 5, Informative

      Doesn't matter.. you aren't going to get better than 10m accuracy without DGPS and 1m with it. Surveys have to be right to centimetres - no GPS can do that (possibly some of the military stuff, but I'd be surprised if even they were that accurate).

      You don't need military GPS to be that accurate, it can be done with differential phase GPS. See: here. By using a fixed base station at a location with known coordinates, one can expect to see accuracies in the 1 to 2 cm range as long as the receiver is within 10's of km from the base station. There are several manufacturers who make gear that can achieve this level of accuracy, see Leica, Magellan, and Sokkia. I've been using Leica gear at work mostly, and have see ~1cm accuracy under good conditions pretty consistently. A lot of legal surveying in remote areas is done exclusively with GPS, especially in the northern parts of B.C and Alberta. I've done legal surveys with GPS in the Vancouver area, but getting high accuracy in urban areas is more difficult because of multi-path noise and qoor signal quality from obstructions such as buildings. Also people in the city get mad when you cut down trees to get better reception ;)

    2. Re:Surveyors are going to start having problems... by plover · · Score: 4, Informative

      Even when trying to take a fix on the same point over time, the margin of error is random. Most of the error is due to propagation delays of the signal. The atmosphere is constantly changing density - the jet stream can raise or lower air pressure between you and satellite #5 at this point in time, or between you and satellite #23 at another point in time. The ionosphere can cause delays or reflections. Nearby buildings, or cars, or airplanes can cause ghost signals. Remember your high school physics teacher who always qualified the the speed of light with the phrase "in a vacuum"? It really makes a difference.

      Remember, the GPS satellites are flying in lower earth orbits, and are constantly moving over and around you. They are not fixed relative to you the same way a geosynchronous satellite is (like the DirecTV satellites.) So even if the weather patterns could be precisely measured and figured out, they would be meaningless as soon as the satellite moved - and they're always moving very, very fast.

      Differential-GPS improves accuracy by having a mounted GPS receiver at a precisely surveyed point, then transmitting (via FM) the "error difference" between what is derived from the GPS system and the surveyed coordinates. If the error at a particular time is 3 meters at the DGPS antenna, then the error at any other GPS receiver in the area is probably pretty close to 3 meters at that same time (assuming the weather patterns are similar between you and the DGPS antenna.)

      You can indeed leave a GPS fixed in a point and average the readings to reduce the margin of uncertainty, but you'll never achieve the high accuracy needed for surveying.

      --
      John
    3. Re:Surveyors are going to start having problems... by ptbarnett · · Score: 4, Insightful

      Doesn't matter.. you aren't going to get better than 10m accuracy without DGPS and 1m with it. Surveys have to be right to centimetres - no GPS can do that.

      Yes, they can. They just aren't consumer handheld GPS receivers:

      http://www.trimble.com/survey/GNSS-Surveying-Systems.aspx

      They don't give instant position: they accumulate data over a period of time and use that to derive the exact position, usually after correcting it with a comparable stream of data collected from a nearby known reference point.

      Under ideal situations the accuracy of GPS equipment can approach 5 millimeter[...]

    4. Re:Surveyors are going to start having problems... by ll1234 · · Score: 4, Informative

      The DGPS system at Libby Dam in Montana is accurate to 1-mm vertically:

      Performance Monitoring Of Libby Dam With A Differential Global Positioning System UNITED STATES SOCIETY OF DAMS (JUNE 2005)

  6. This is like the Millenium Bug by macraig · · Score: 4, Interesting

    Plenty of people anticipated this, but nobody has given a shit enough about it to do anything substantial. I was first hearing warnings about this years ago. As a programmer, I anticipated the Millenium Bug almost 20 years beforehand, and refused to take those shortcuts that everyone else thought were wise. Back on the GPS Ranch, meanwhile, the EU is busy putting its own superior system in place, in part because they don't want to be dependent upon our system, esp. if and when we fuck up and fail to keep it operational.

    Just one more reason to move to Europe.

    1. Re:This is like the Millenium Bug by quanticle · · Score: 5, Insightful

      Why move to Europe? I mean, its not like they'll not be restricting the system so that it only works over Europe. Why not just buy a Galileo receiver (when they become available)?

      Also, isn't Galileo supposed to be backwards compatible with GPS?

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    2. Re:This is like the Millenium Bug by plover · · Score: 4, Funny

      As a programmer, I anticipated the Millenium Bug almost 20 years beforehand

      So did I. But some companies still wanted two digit years because it was "too hard" to enter four digit years.

      In 1998 I made a killing :-)

      Ha! I made my killing in 98, not 1998.

      --
      John
  7. You can't touch military spending. by copponex · · Score: 4, Interesting

    They defend "freedom."

    I'm all for opening up completely the books of any government subcontractor. If you don't like transparency, then don't take government contracts. It may be tough to police, with companies trying to cheat with subsidiaries, but I think the payoff would be enormous.

    On 9/10/2001, Rumsfeld gave a speech about wasteful military spending. Check it out in print, or a small piece on CBS. There was a link to his whole speech years ago - I don't know where that went. In it he states that up to 2.3 trillion dollars is "unaccounted" for, whatever that means. If you read between the lines, he is pushing for privatization of the military. We all know how well that worked out.

    1. Re:You can't touch military spending. by Martin+Blank · · Score: 4, Interesting

      Rumsfeld did have ideas which would have lowered overall spending had they succeeded. However, they flew in the face of thousands of years of military history, and are seen as having been instrumental in what was eventually a rather unceremonious exit. He essentially wanted to go to an all-Special Forces military, with only a few legacy systems for those cases when a couple of massive non-nuclear punches were required. I don't know if he watched Navy Seals one too many times, but nothing replaces boots on the ground when you want to hold ground -- something that Special Forces are not intended to do.

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  8. Re:Everyone's favorite hobby. by mpoulton · · Score: 4, Funny

    "What about Goecaching!?" Every nerds favorite hobby could be in jeopardy!

    "Everyone" is subjective, "hobby" is misleading and "favorite" is relative... very relative. ;)

    "nerd" was right on, however.

    --
    I am a geek attorney, but not your geek attorney unless you've already retained me. This is not legal advice.
  9. Re:Europe to the rescue! by plover · · Score: 5, Funny

    Oooh, a new acronym!

    RAFES - Redundant Arrays of Fucking Expensive Satellites.

    --
    John
  10. Re:Best not one system... LORAN, Fuller, Cold War by j-stroy · · Score: 5, Interesting

    A friends mom escaped the wreck of a 90ft Fish Packer as it hit the rocks at night in a passage with strong currents due to a problem caused by relying on GPS. It was due to something like how it derived the heading vs the direction of travel or some-such.

    Moral of the story was that using static ground stations like LORAN, this would not have occurred. Anyhow, now ground stations have been dismantled and vessel's receivers scrapped and there is nothing groundbased to replace GPS with should GPS fail. High altitude communications aircraft seem viable; however, there again is a reliance on something that is not physically bolted down and easily fixable.

    An interesting footnote is mentioned by Buckminster Fuller in his 50 year summation masterwork "Critical Path": on pages 186-7. The Americans started their radio-accurate mapping from Compass Island in Penobscot Bay in Maine, and proceeded by radio triangulation to work their way down to South America, across the Atlantic and up Africa to Europe. This was needed for accurately guiding bombers above the clouds, as the ground survey maps were often 10's of miles incorrect.

    The Germans had done this as well for Europe and perhaps Russia, so when Berlin fell, the Russians went in early and took the German mapping data. Russia had radio-accurate maps of all of Europe and published data from the US, while the US did not have maps of Russia. This lead to the importance in the cold war of US spy planes and satellites for basic mapping for targeting ICBM's, including as suggested by Fuller a US presence in Iran and Afghanistan as radio triangulation bases. Russia performed massive deceptions of fake cities and so on to perpetuate this information gradient.

  11. Not a normal event, but an exceptional one by Chmcginn · · Score: 5, Interesting

    solar event will cause transient events that will recover in a few seconds

    A normal event, sure. But a repeat of the 1859 solar flare would likely damage many satellites not in the Earth's shadow at the height of the impact. Is the whole GPS constellation set up to handle that type of event? Or would more than half the satellites go down in a hour?

    --
    Have you been touched by his noodly appendage?
  12. Re:Best not one system... LORAN, Fuller, Cold War by digitig · · Score: 5, Informative

    A friends mom escaped the wreck of a 90ft Fish Packer as it hit the rocks at night in a passage with strong currents due to a problem caused by relying on GPS. It was due to something like how it derived the heading vs the direction of travel or some-such.

    Something wrong there. Both LORAN and GPS only give position (GPS gives time too, but that doesn't help here). Direction of travel is determined in both systems by taking the difference in position over a known time interval. GPS can give heading by using the phase difference between receivers on different parts of the vessel, whereas the wavelength of LORAN was probably too long for that to work. Upshot is, a problem involving headings and direction of travel isn't the fault of GPS, and using LORAN would have been no defence. It may have been a problem with the GPS receiver software, but LORAN calculations could go wrong too. Most likely it was a navigator not understanding the systems they had.

    --
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  13. More than GPS by proudfoot · · Score: 4, Informative

    There's more than just GPS.

    Here's a listing of all current/proposed global systems. Regional only systems such as IRNSS or Beidou1 are not listed.

    GPS - United States - Fully Operation
    Galileo - EU/China/Israel/South Korea/Norway/Etc - 2013
    Beidou2/Compass - China - 2012?
    GLONASS/ - Russia/India - Complete in 2010