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GPS Accuracy Could Start Dropping In 2010

timothy posted more than 5 years ago | from the how-to-blackmail-for-tax-dollars dept.

Earth 210

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."

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Where's Waldo? (5, Funny)

Anonymous Coward | more than 5 years ago | (#27958839)

There he is! No, wait...

How about cutting the dead wood? (4, Insightful)

mr_stinky_britches (926212) | more than 5 years ago | (#27958851)

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

Re:How about cutting the dead wood? (5, Insightful)

FireFlie (850716) | more than 5 years ago | (#27959205)

Just your 1/50th of a cent?

Re:How about cutting the dead wood? (5, Funny)

Anonymous Coward | more than 5 years ago | (#27959529)

.02Vc (Verizon cents)

Re:How about cutting the dead wood? (5, Funny)

jeepien (848819) | more than 5 years ago | (#27960283)

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

You can't touch military spending. (4, Interesting)

copponex (13876) | more than 5 years ago | (#27959499)

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 [defenselink.mil] , or a small piece on CBS [youtube.com] . 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.

Re:You can't touch military spending. (2, Insightful)

ktappe (747125) | more than 5 years ago | (#27959939)

On 9/10/2001, Rumsfeld gave a speech about wasteful military spending

Given his position as Secretary of Defense, he was in the best possible position to fix the woes he spoke of. How'd that work out? It's funny how you fail to fix problems when you have a financial interest in not seeing them fixed. Sure would be interesting to see a full accounting of Rumsfeld's and Cheney's accounts these days, and just how much Northrup Grumman, Lockheed Martin, Boeing, and Halliburton all enhanced their retirements.....

Re:How about cutting the dead wood? (2, Insightful)

shipofgold (911683) | more than 5 years ago | (#27960287)

This is a mergers and acquisitions problem. Having worked for a large company and gone through more than one merger/divestiture/early retirement buyout/staff cutting/staff building/etc. I have seen a lot of history and knowledge walk out the door. When projects get shuffled around and re-organized it is inevitable you end up with people who are out of their depth trying to make sense of the previous work and in many cases just redoing it because they don't understand it. Not a case of incompetance on the developers part....just too much to learn in too short of time.

Just in time for Galileo (4, Insightful)

MichaelSmith (789609) | more than 5 years ago | (#27958907)

Best not to rely entirely on one system anyway.

Re:Just in time for Galileo (5, Funny)

Anonymous Coward | more than 5 years ago | (#27959231)

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

Re:Just in time for Galileo (2, Informative)

Scrameustache (459504) | more than 5 years ago | (#27959925)

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

Get with the times, you anachronistic clod!

Thanks to his intuition as a brilliant physicist and by relying on different arguments, Galileo, who practically invented the experimental method, understood why only the sun could function as the centre of the world, as it was then known, that is to say, as a planetary system. The error of the theologians of the time, when they maintained the centrality of the Earth, was to think that our understanding of the physical world's structure was, in some way, imposed by the literal sense of Sacred Scripture....
â" Pope John Paul II, L'Osservatore Romano N. 44 (1264) - November 4, 1992

http://en.wikipedia.org/wiki/Galileo_affair#Modern_church_views [wikipedia.org]

In 2000, Pope John Paul II issued a formal apology for all the errors of the Church over the last 2000 years including the trial of Galileo among others.

Re:Just in time for Galileo (0, Troll)

MichaelSmith (789609) | more than 5 years ago | (#27960125)

In 2000, Pope John Paul II issued a formal apology for all the errors of the Church over the last 2000 years including the trial of Galileo among others.

Thats why I never accept apologies. If they were really sorry they wouldn't have done it in the first place.

You're only a few hundred years off... (1, Insightful)

Anonymous Coward | more than 5 years ago | (#27960521)

> Thats why I never accept apologies. If they were really sorry they wouldn't have done it in the first place.

Wait. You think that John Paul II (or anyone else alive today) was the one who put Galileo on trial!? Or do you use that strange variant of the word "they" which lumps together both guilty and innocent alike (AKA "guilt by association").

Re:Just in time for Galileo (5, Funny)

Repton (60818) | more than 5 years ago | (#27960557)

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

Re:Just in time for Galileo (0, Redundant)

ManWithIceCream (1503883) | more than 5 years ago | (#27959255)

Just what I thought.

One System to Rule Them All (0)

RudeIota (1131331) | more than 5 years ago | (#27959607)

Best not to rely entirely on one system anyway.

Okay, so I'll just use that other GPS system.

Oh, wait a second...

Re:Best not one system... LORAN, Fuller, Cold War (5, Interesting)

j-stroy (640921) | more than 5 years ago | (#27959913)

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 [bfi.org] in his 50 year summation masterwork "Critical Path": [easystorecreator.com] on pages 186-7. [amazon.ca] 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.

Re:Best not one system... LORAN, Fuller, Cold War (1)

MichaelSmith (789609) | more than 5 years ago | (#27960111)

Some people in aviation are using a combination of the two. They locally transmit an offset to GPS, based on the known position of a fixed GPS reciever.

Re:Best not one system... LORAN, Fuller, Cold War (5, Informative)

digitig (1056110) | more than 5 years ago | (#27960307)

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.

Re:Best not one system... LORAN, Fuller, Cold War (1)

SvnLyrBrto (62138) | more than 5 years ago | (#27960335)

Don't ships' navigators still train on sextants and chronometers?!?!?

I don't know if it's a holdover from my days as a boy scout or what, but I almost always have a backup, and a backup of the backup of anything critical to my survival. And if I ever get rich enough to own my own ocean-going vessel, *I* sure wouldn't put to sea without a sextant and the training to use it. And I'm just some not-a-professional-ship's-navigator schmuck.

Re:Best not one system... LORAN, Fuller, Cold War (1)

timeOday (582209) | more than 5 years ago | (#27960351)

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.

You can't draw that conclusion until you know what went wrong with the gps-based system, and what goes wrong with ground-based system. It's not as if the obvious alternative to a flawed system is using a perfect system instead, or even a (more complex) combination of systems.

Re:Best not one system... LORAN, Fuller, Cold War (1)

j-stroy (640921) | more than 5 years ago | (#27960491)

I don't remember the detail of the story; However, the point of it being a failure due to GPS issue was relayed by my friend (the daughter). The vessel was a packer named "The Salty Isle" and is known by some in the BC area. The seafood-diver fleet was in the area and made a midnight storm rescue of all hands from a nasty rock.

I seem to recall that the amount of current in the passage (at night) was the problem, and that the drift was not noted by the Skipper with the GPS instrument because of a constant reading, whereas with their LORAN set, a drift would have been noted by a varying value. Ya can tear it apart and IANAGPSLORANO, sorry.

But do read Critical Path, it is worthwhile, including Fuller's description of a Geoscope which it seems Google Earth is modelled after.

How much is actually going to be lost? (5, Insightful)

Chmcginn (201645) | more than 5 years ago | (#27958911)

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.

Re:How much is actually going to be lost? (4, Funny)

Shadow of Eternity (795165) | more than 5 years ago | (#27958997)

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.

Re:How much is actually going to be lost? (2, Funny)

master5o1 (1068594) | more than 5 years ago | (#27959093)

North is ALWAYS that way ... --->

Re:How much is actually going to be lost? (2, Insightful)

hezekiah957 (1219288) | more than 5 years ago | (#27959167)

That's south for me, given the current orientation of my computer.

Re:How much is actually going to be lost? (5, Funny)

master5o1 (1068594) | more than 5 years ago | (#27959225)

You must be using your computer wrong.

Re:How much is actually going to be lost? (1)

ChunderDownunder (709234) | more than 5 years ago | (#27959349)

Perhaps, like me, (s)he's from the southern hemisphere [wikipedia.org] .

Re:How much is actually going to be lost? (1)

ijakings (982830) | more than 5 years ago | (#27959403)

Now come on, who are you kidding with the (s)he.

You must be new here.

(Well aware my UID is higher than yours)

Re:How much is actually going to be lost? (1)

ChunderDownunder (709234) | more than 5 years ago | (#27959617)

Well, sorry. I've been reading a book on sociolinguistics which discusses gender specific pronouns...

Re:How much is actually going to be lost? (0, Offtopic)

The_Wilschon (782534) | more than 5 years ago | (#27960319)

Just out of curiosity, what book? (My wife, a historical linguist, teaches a class called "Language, Sex, and Gender".)

Re:How much is actually going to be lost? (1)

ChunderDownunder (709234) | more than 5 years ago | (#27960469)

Trudgill's Sociolingustics [amazon.com] . I'm not sure whether it's an authoritative work on the discipline but it was at the local library. :-) It's a fairly broad book covering a number of topics. The chapter I was referring to details the differences in pronunciation, vocabulary and historical evolution of languages based on male/female biases etc. (I've been wondering about studying applied lingustics by distance education.)

Re:How much is actually going to be lost? (3, Funny)

slarrg (931336) | more than 5 years ago | (#27959247)

You're probably reading he wrong end of the needle.

Re:How much is actually going to be lost? (1)

BikeHelmet (1437881) | more than 5 years ago | (#27960047)

I find it funny that you're almost dead on for me. It's pointing north east. :P

Re:How much is actually going to be lost? (1)

Solra Bizna (716281) | more than 5 years ago | (#27960353)

I find it funny that you're almost dead on for me. It's pointing north east.

For me, it actually WAS north. (Fine, a couple degrees west of north, but who's counting?)

-:sigma.SB

Re:How much is actually going to be lost? (0)

Anonymous Coward | more than 5 years ago | (#27960239)

The southwest for me. My monitor faces northwest.

Re:How much is actually going to be lost? (5, Funny)

The Archon V2.0 (782634) | more than 5 years ago | (#27959597)

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.

Re:How much is actually going to be lost? (1)

Repton (60818) | more than 5 years ago | (#27960573)

Do they not have a sun where you live?

Re:How much is actually going to be lost? (5, Informative)

evangellydonut (203778) | more than 5 years ago | (#27959387)

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)

Not a normal event, but an exceptional one (5, Interesting)

Chmcginn (201645) | more than 5 years ago | (#27960005)

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 [wikipedia.org] 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?

Europe to the rescue! (3, Insightful)

Anonymous Coward | more than 5 years ago | (#27958915)

Ah, and you all laughed when Europe started to launch Galileo sats. Haha!

Re:Europe to the rescue! (2, Interesting)

WidescreenFreak (830043) | more than 5 years ago | (#27959817)

We did? Funny, I thought that most of the replies on /. might have questioned it but eventually agreed that it's not a bad idea to have a redundant array of satellites out there.

Re:Europe to the rescue! (5, Funny)

plover (150551) | more than 5 years ago | (#27959905)

Oooh, a new acronym!

RAFES - Redundant Arrays of Fucking Expensive Satellites.

Re:Europe to the rescue! (3, Funny)

jeepien (848819) | more than 5 years ago | (#27960371)

It's spelled RAFES, but it's pronounced "ralphs".

Re:Europe to the rescue! (1)

plover (150551) | more than 5 years ago | (#27960591)

I was kind of thinking they "rafed" us taxpayers to fund it, but your explanation works too.

Re:Europe to the rescue! (1)

saiha (665337) | more than 5 years ago | (#27959875)

If anything I would have expected "its about time" posts, seeing as Europe has been using the US stuff for free.

Re:Europe to the rescue! (1)

ktappe (747125) | more than 5 years ago | (#27959967)

Ah, and you all laughed when Europe started to launch Galileo sats. Haha!

Side question: Would it be possible to design a GPS receiver that made use of both the US and Euro birds? Could the two systems be used as each others' backup?

Re:Europe to the rescue! (1)

SwedishPenguin (1035756) | more than 5 years ago | (#27960185)

From what I've read, Galileo receivers will be able to receive GPS signals, increasing the number of satellites available to triangulate your position and thereby increasing accuracy.

Re:Europe to the rescue! (2, Informative)

digitig (1056110) | more than 5 years ago | (#27960399)

Yes. There have already been dual GPS/GLONASS systems for many years, so a triple GPS/GLONAS/Galileo system should be no problem. You could even throw EGNOS in. Of course, it will cost more, which is why few people have bothered with the dual GPS/GLONASS kit since GPS is good enough for most purposes.

Surveyors are going to start having problems... (5, Interesting)

yourassOA (1546173) | more than 5 years ago | (#27958955)

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.

Re:Surveyors are going to start having problems... (1)

captnbmoore (911895) | more than 5 years ago | (#27959113)

No they wont. http://surveyorsnotebook.com/ [surveyorsnotebook.com] If I were to purchase a plot of land ad it had gps coordinates as the buoundary then they would be hiring a certfied surveyor to redo it. GPS is great for maritime , road, and outdoor navigation but is no where near accurate enough for surveys.

Re:Surveyors are going to start having problems... (2, Informative)

MichaelSmith (789609) | more than 5 years ago | (#27959207)

No they wont. http://surveyorsnotebook.com/ [surveyorsnotebook.com] If I were to purchase a plot of land ad it had gps coordinates as the buoundary then they would be hiring a certfied surveyor to redo it. GPS is great for maritime , road, and outdoor navigation but is no where near accurate enough for surveys.

Well not if you just walk around with an etrex, but surveyors have more accurate gear than that. Not sure if they still use differential GPS though.

Re:Surveyors are going to start having problems... (0)

Tony Hoyle (11698) | more than 5 years ago | (#27959305)

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).

Re:Surveyors are going to start having problems... (2, Insightful)

tsm_sf (545316) | more than 5 years ago | (#27959549)

Surveys have to be right to centimetres

No, they just have to be consistent.

Re:Surveyors are going to start having problems... (1)

MichaelSmith (789609) | more than 5 years ago | (#27959591)

Well my etrex claims four metre accuracy with good cover. Differential GPS has been used for decades to measure small movements of the earth across geological faults. That must require millimetre accuracy.

Re:Surveyors are going to start having problems... (1, Insightful)

Anonymous Coward | more than 5 years ago | (#27959609)

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).

C-Nav DGPS has 11 cm resolution in 3-d. Suck it.

Re:Surveyors are going to start having problems... (2, Informative)

Anonymous Coward | more than 5 years ago | (#27959619)

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 are simply wrong. RTK GPS is accurate to a centimeter. Surveying, however, relies on a benchmark, which means that you won't have centimeter accuracy unless the benchmark is perfectly recorded, perfectly preserved, and can be found perfectly a second time.

Re:Surveyors are going to start having problems... (5, Informative)

rir (632769) | more than 5 years ago | (#27959823)

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 [wikipedia.org] . 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 [leica-geosystems.com] , Magellan [magellangps.com] , and Sokkia [sokkiacanada.com] . 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 ;)

Re:Surveyors are going to start having problems... (4, Insightful)

ptbarnett (159784) | more than 5 years ago | (#27960073)

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 [trimble.com]

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[...] [purdue.edu]

Re:Surveyors are going to start having problems... (1)

timeOday (582209) | more than 5 years ago | (#27960463)

Moreover, Galileo is designed for cite).

Re:Surveyors are going to start having problems... (2, Informative)

iroll (717924) | more than 5 years ago | (#27960131)

The engineers at Trimble would probably take issue with that statement, since they sell high-dollar ($10~$100k) survey equipment that produces reliable >0.1' accuracy (wikipedia states 20mm as a working number). I worked with equipment in 2003 that was at least 5 yrs old then, and it was that good. The key, as other posters have mentioned, is a base station and some fancy calculations that make it possible.

I'm pretty sure that this equipment has been around since well before the Clinton administration ended the obfuscation/degradation of GPS signals; it just isn't practical for your typical consumer gear.

Re:Surveyors are going to start having problems... (2, Informative)

RockClimbingFool (692426) | more than 5 years ago | (#27960147)

That is why surveyors buy surveyor GPS gear. The shit ain't cheap, but when you want centimeter accuracy, you have to buck up.

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

Basically, you set up your own local differential GPS station that sits for a while and figures out its position to a very high degree of accuracy.

You then use very accurate devices capable of sub meter accuracy with time averaging and DGPS, and use the signal from the local station to get even better accuracy than that.

Getting accurate positions for surveying isn't that hard, since you can time average, add local DGPS stations and correct the data even after its been collected. You just need the gear.

Now if you want real time tracking with sub meter accuracy, that is very hard.

Re:Surveyors are going to start having problems... (3, Informative)

digitig (1056110) | more than 5 years ago | (#27960523)

Except that's now how surveyors survey. Yes, DGPS has errors in absolute position, but surveyors use triangulation from fixed points. Surveyors are routinely using relative positions of a pair or network of receivers using phase tracking to get centimeter accuracy. This isn't fancy military stuff, it's off-the-shelf civilian kit you could buy today. It's differential, but not as you know it.

Re:Surveyors are going to start having problems... (3, Informative)

rir (632769) | more than 5 years ago | (#27959521)

Differential Phase GPS is accurate enough for legal surveys (in British Columbia at least... I believe most of the rest of Canada as well).
Btw, IAAS

Not if using a transmitter on the earth's surface (0)

Anonymous Coward | more than 5 years ago | (#27959323)

If you have a ground-based transmitter reference, gps can be accurate to within centimeters in 3D space.

Re:Surveyors are going to start having problems... (1)

fredklein (532096) | more than 5 years ago | (#27959849)

GPS is great for maritime , road, and outdoor navigation but is no where near accurate enough for surveys.

I always wondered- I know GPS has a margin of error, but is that error consistent or random?

What I mean is, if I place a GPS device at a known location and take a reading, and it is off by 'X' amount, will that reading always be off by that amount? If so, then I should be able to compensate for it.

On the other hand, if the reading is off by a different random amount each time, can't I just take a bunch of readings and average them? Wouldn't that give me higher precision?

Re:Surveyors are going to start having problems... (4, Informative)

plover (150551) | more than 5 years ago | (#27960061)

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.

Now someone is taking the P**S (-1)

Anonymous Coward | more than 5 years ago | (#27959021)

2004 compromise makes it possible both for the United States to block the Galileo frequencies and for the two systems to interoperate in the future.

Just who the hell do there darn people think they are Europe builds and launches a system and frickin yanks want to be able to cripple it because they want to kiss my shiny butt as like go stand in the shuttles SRB at launch time i say

That's OK. By then GLONASS will be fully operation (2, Informative)

melted (227442) | more than 5 years ago | (#27959075)

That's OK. By then Russian GLONASS will be fully operational and both the Europeans and the Chinese are thinking of launching their own satellite navigation systems. Out of these three, chances are at least one will be available for the US to use in case of a global conflict.

This is like the Millenium Bug (4, Interesting)

macraig (621737) | more than 5 years ago | (#27959091)

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.

Re:This is like the Millenium Bug (5, Insightful)

quanticle (843097) | more than 5 years ago | (#27959155)

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?

Re:This is like the Millenium Bug (1)

saiha (665337) | more than 5 years ago | (#27959767)

Its been a long time since I've looked into Galileo but I would have to say that the positioning is done virtually the same as GPS. Though I think galileo probably has more orders of ephemeris data. The basics are the satellite gives you enough info for you to figure out where it is, then you find the distance from you to the satellite and triangulate your position.

Re:This is like the Millenium Bug (2, Interesting)

evangellydonut (203778) | more than 5 years ago | (#27959429)

I was first hearing warnings about this years ago.

Hmm... years ago, Boeing wasn't 3 years behind on launch schedule, and we wouldn't have this issue. If the AirForce had known 3 years ago, they would've exercised some option to build more IIMR builds. Boeing kept on pushing the launch date back, 3 months at a time, and here we are.

Re:This is like the Millenium Bug (1)

macraig (621737) | more than 5 years ago | (#27960209)

I know I heard of it before I moved where I live now, and that would place it more than three years ago. I don't think I heard it from Slashdot the first time around. The source might have been my uncle (well-connected aerospace engineer, worked @ China Lake, Lockheed, JPL).

Re:This is like the Millenium Bug (1)

RetroGeek (206522) | more than 5 years ago | (#27959603)

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 :-)

Re:This is like the Millenium Bug (4, Funny)

plover (150551) | more than 5 years ago | (#27960071)

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.

Re:This is like the Millenium Bug (0)

Anonymous Coward | more than 5 years ago | (#27959635)

As a programmer, I anticipated the Millenium Bug almost 20 years beforehand, and refused to take those shortcuts that everyone else thought were wise.

And exactly how much money did you make by updating your software to be year 2000 compatible... oh wait you didn't.

Which choice was wise is a matter of perspective.

And just for the record, I noticed this issue as well in the 7th grade when I first started programming on my Tandy (it had color, and sound!). And so did several other classmates. I actually mentioned it to a programmer who my parents knew, guess what he said? "Most of that software will be abandoned long before 2000, and whatever is left over will be easy money for guys like me." He then went on to say "Why make my life more difficult now, especially when I can make more money later?".

And that pretty much sums up the whole Y2K thing.

Re:This is like the Millenium Bug (0)

Anonymous Coward | more than 5 years ago | (#27959797)

First, you are an idiot.

Second, the US has been holding Europe's hand for over a decade now because they couldn't figure out how to make a GPS system themselves.

Re:This is like the Millenium Bug (1)

digitig (1056110) | more than 5 years ago | (#27960589)

I think you'll find that the first European GPS-like system -- GLONASS -- was done with very little help from the USA.

Re:This is like the Millenium Bug (1)

argStyopa (232550) | more than 5 years ago | (#27959811)

I'm sure everyoone's delighted to hear how much more intelligent you are than everyone else! Congratulations, I'm sure your mom is proud.

"EU is busy putting its own superior system in place"
Really? How many satellites (of 30) have they lofted again?

It looks more to me like the EU is pissing and moaning and backstabbing each other to leave Galileo a boondoggle that will only allegedly fly by 2013. One might argue that the US system, being actually operational, is far more likely to be upgraded on-time than the Galileo system which is still mostly EU promises and vaporware.

And as far as "superior" (in case you mean it technically, and not just morally), I'll remind you that some of the US GPS satellites have been in space nearly TWENTY years. One might logically presume that a system two decades newer might have some newer better features, but I'd also guess that the GPS block 3(?) upgrade will be fairly comprehensive (and if you think SA is really disabled, I have some swampland in Florida I can sell you).

I'd say however, that we'd be nevertheless delighted if you took all these good reasons to move to Europe as an invitation. Please don't let the door hit your ass on the way out. K'thx.

Re:This is like the Millenium Bug (1)

BikeHelmet (1437881) | more than 5 years ago | (#27960105)

I'm like you, dude! Incredible foresight!

I submitted a bug to Macromedia back when Flash 5 had just came around. I told them the version checking code fragment listed on their site wouldn't work once they hit Flash 10, and submitted code that looked for a space or a digit after the first number.

They never did update it. Years later, when Flash 10 was finally released, any .swf files using the old actionscript broke, reporting you have to upgrade your flash player despite having the newest one. :P

Some developers are incompetent and can't think ahead. Others just don't care. To some people, it's just a way to pay the bills, rather than an art...

Hardware can fail? (2, Insightful)

Bellegante (1519683) | more than 5 years ago | (#27959133)

This isn't news. The article simply says that there have been problems getting new satellites in orbit; but the ones that are there are functioning fine. Yes, they COULD fail, but they haven't done so yet, and there isn't yet any indication that they will.

Move along, move along.

Re:Hardware can fail? (3, Informative)

Anonymous Coward | more than 5 years ago | (#27959317)

Actually the GPS satellites aren't failing fast enough. It's my understanding that the Air Force has multiple satellite sitting on the ground waiting to launch but the ones on orbit aren't dying fast enough (some of them are already at twice their design life and still going strong)

I was also under the impression that there are currently 29 satellites in orbit, which means that 5 would have to fail before we even get down to a constellation of 24, and they can launch spares before that happens!

Ha HA to all you nay sayers! (0, Redundant)

The Outlander (1279696) | more than 5 years ago | (#27959277)

You see, you all laughed at my iPhones inability to guide me safely through the streets.

It just goes to show that my iPhone is so advanced you guys are not going to catch up with my tech until 2010!

EAT THAT SUCKERS

what would you pay for gps? (2, Interesting)

docbrody (1159409) | more than 5 years ago | (#27959339)

When you think about it, GPS is a pretty cool "service" that the US government supplies for free to the world. Obviously tom toms, garmins, etc, cost money but the service itself is free (And NO I am not trying to start a political flame war here, i just think GPS is cool)

People pay for satellite radio. If we were not all so accustomed to free GPS, I wonder how many of us would pay a monthly fee for it.

Personally, I don't use GPS enough to even pay $1 a month for it. But I might not mind paying an extra sales tax when I buy a GPS enabled device - something that goes to maintaining the satellites.

Re:what would you pay for gps? (1)

saiha (665337) | more than 5 years ago | (#27959829)

I already pay for GPS in my taxes. Yes people who don't pay taxes and people who don't pay taxes to the US government still get to use it. But seeing as how easy it is to make a GPS device now, I doubt that non-US citizens would pay an extra tax for it /shrug.

Re:what would you pay for gps? (1)

jargon82 (996613) | more than 5 years ago | (#27959897)

I don't understand why parent is modded down... Anyone?

Looks like... (0, Offtopic)

owlnation (858981) | more than 5 years ago | (#27959371)

a job for the Dharma Initiative...

Daniel Jackson (1)

ijakings (982830) | more than 5 years ago | (#27959481)

We should be fine as long as we dont let Daniel Jackson Get ahold of them [jackfic.net]

Re:Daniel Jackson (0)

Anonymous Coward | more than 5 years ago | (#27959881)

You don't have permission to access /gallery/albums/screencaps/season 4/417 Absolute Power/PDVD_177.jpg on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

That is a rocking picture!!!!

Re:Daniel Jackson (1)

JoshuaZ (1134087) | more than 5 years ago | (#27959971)

The link is not working. I presume it is however a reference to the Stargate SG-1 episode where Daniel Jackson is given all the technological knowledge of the Gouald (the primary alien menace for most of the series) and he is then corrupted into building a massive set of death ray satellites above Earth which he uses to unite Earth more or less under his control (after frying Moscow among other activities). At the end of the episode we find out that it was all in his mind and was a lesson from a boddhisatva like alien energy being.

What about Geocaching!? (1, Funny)

mc1138 (718275) | more than 5 years ago | (#27959505)

Every nerds favorite hobby could be in jeopardy!

Everyone's favorite hobby. (1)

RudeIota (1131331) | more than 5 years ago | (#27959637)

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

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

Re:Everyone's favorite hobby. (4, Funny)

mpoulton (689851) | more than 5 years ago | (#27959711)

"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.

Re:Everyone's favorite hobby. (1)

mc1138 (718275) | more than 5 years ago | (#27960235)

Haha fair enough, still, not totally sure what makes this flamebait...

When news breaks: Timothy to the rescue! (-1, Troll)

Dahamma (304068) | more than 5 years ago | (#27959665)

Ok, I hate to hate, but why is it whenever there is a totally ridiculous sensationalistic story like this (the original source is "TidBITS, Mac news for the rest of us"!?) it's Timothy doing the posting?

TFA non-story even ends with a "personal" opinion that oh, just maybe the technology used by much of the latest US armed forces, its arsenal, and their $500B+ budget may not be left to rot... you THINK?

In other words: (0, Redundant)

the_other_chewey (1119125) | more than 5 years ago | (#27959877)

GPS Accuracy Could Start Dropping In 2010

...or maybe not.

Will software defined receivers be common? (3, Interesting)

ShooterNeo (555040) | more than 5 years ago | (#27959953)

Are the 3 different GPS systems being proposed (U.S., Galileo, a possibly Russian system) be broadcasting on frequencies close enough to each other that receivers that use all 3 systems will be common and fit into cell phones?

That would be the best outcome : software defined receivers that can pick up a signal from any satellite positioning signal in the sky : GPS, wide area differential GPS, Galileo, everything. Massive redundancy would mean that if you were to go between buildings or even inside buildings, there would be a greater chance that at least some of the satellites were still visible.

Everything that depends on global positioning would work better : from airline navigation systems to X prize landers.

A non-story (1)

Politicus (704035) | more than 5 years ago | (#27960075)

WAAS is the limiting factor in most units and most cases (near urban areas) so this is a non-story. Besides, the people going for those kind of caches are experienced at reading environmental clues anyways, so not much effect there either.

Government problem solution... commercial sector. (1)

blantonl (784786) | more than 5 years ago | (#27960509)

It sounds to me like a cry for help directed to the public sector, from the US Government.

Imagine a subscription/license service for a geo-location broadcast platform from space that is unrestricted to users and as accurate as science knows how to make such things "accurate." How much do you think that license would be worth?

Scary? Absolutely.

Possible? More Absolutely!

There is serious money in geo-location today. Not just to target nuclear warhead.. if you call that a business.

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