GPS rollover problem was deliberate : LUSENET : TimeBomb 2000 (Y2000) : One Thread

It seems pretty suspicious to me that this incredibly stupid logic error just "happened" to cause problems at this time.

The pollys take it as vindication for their views. "See, nothing happened - just like nothing will next year."

The masses have now widely heard about the GPS problem through the media. It was (rather predictably) a non-event: a few sailors with old GPS receivers get lost.

That is not how the media will portray it: the story has been given big headlines before, and now the implication for most will be "GPS non-event = Y2K non-event".


-- Y2KGardener (, August 21, 1999



If nobody knows what is going to happen then how can it all be a big conspiracy?

-- (wondering@about.doomer disconnect), August 21, 1999.

I thought that would bring the Pollys out! Your views are already known. Go back to sleep.

-- Y2KGardener (, August 21, 1999.


First off, the size of the data field for the GPS weeks limits the number of weeks to 1024. (1023 if it is a signed field) The starting week was 0, and every week it adds 1. When you try to add 1 to 1024 in a field that can hold a maximum of 1024, then you will roll back to either a 0 or a 1, depending upon your programs.

This is nothing compared to the rollover of 1999 to 2000 in all reality.

-- (cannot-say@this.time), August 21, 1999.

Oh touche!! touche! (sarcastic clap)

Now you want to tell me how it is the gubmint is keeping all this stuff from you when you all say that NOBODY KNOWS WHAT IS GOING TO HAPPEN?

That's right, put the tinfoil helmet in the cloest for a second and speak in english... HOW IS THIS POSSIBLE? Is it, precognition? Are the gubmint workers touched by GOD?

Please, I stand here before you ready to be amazed...

-- Y2K Gardener (the@amazing.lunkhead), August 21, 1999.

Honey, dont be so bitter that the GPS thingy didnt make people soil their pants. Maybe something else will come along and make everyone go "Oh me oh my, Y2k will be like this, off to Costco I go!".

Gardener, the masses have a right to look at Y2k as a non-event because nothing has happened so far and the GPS was more proof that millions of people world wide can fix things in time before it bites them in the ass.

Have a sit down darling and catch your breath, you're all riled up and the red in your cheeks clashes with the tinfoil on your head.

-- Sweetie Pie (, August 21, 1999.


I don't know what "incredibly stupid logic error" you're referring to? 20 years ago, bits were precious. Someone made the decision to implement a 10-bit week counter, good for 20 years (which seems like forever, in the computer world). Besides, when that counter rolls over (and apparently the carry out is ignored) you just start over. This should not affect anything in theory, although in practice I suppose it's possible to create receivers that assume a week counter that increments forever. And sure enough, such receivers were created. But that isn't a GPS problem, and by all indications it isn't a practical problem either.

What's similar is, we have a time counter rollover event, on what is a much smaller scale, to be sure. And while no GPS problem does NOT mean no y2k problem, it ought to be usable to give us some hints -- how effective was remediation of noncompliant receivers? Within the universe of GPS discourse (all transmitters, receivers, and users), what was the damage, what was the error rate, etc. We *might* be able to scale this up much like using shadow-length ratios to calculate the heights of tall buildings. What do you think?

-- Flint (, August 21, 1999.


Don't you think that 16-bits might have been just a *little* bit more logical than 10, bearing in mind how computers work?

As for the rest of you Pollys -

Read my question again - or, better still, let me spell it out to you 'special' people:

Of course no one knows what will happen. The main subject of this forum is whether or not the 'powers that be' are trying to mislead the sheeple over what they believe will be a serious problem. I believe they may be.

As for you, you can believe what you like. More food for us.

-- Y2KGardener (, August 21, 1999.

Y2k is just another way for the imbeciles of society to cry "VICTIM" and weep and go boo-hoo as they spill hot coffee on themselves or when they crash the Lexus as they chat with hubby or wifey on the car phone. Everywhere you look around here it's one more bit of "evidence" of how terrible our modern lives are and the group follows each topic trying to figure WHO was responsible and WHEN they can take revenge for being made into a VICTIM.

-- (just@another.pathetic scam), August 21, 1999.

I guess I made an assumption when I asked "What do you think?". I should have started by asking "Do you think?" because a negative answer obviates further questions.

Anyway, of course the more bits in your counter, the higher you can count before your counter rolls over. And I repeat, 20 years ago those bits were precious. The GPS satellites were designed in the early 70's, and memory at that time was horrendously expensive. Saying "Gee, 16 bits would make more sense" is EXACTLY like Marie Antoinette saying "Let them eat cake".

-- Flint (, August 21, 1999.

* * * 19990821 Saturday

Y2K Gardener: You make an excellent observation.

1.) The GPS rollover debacle was an _intended_ (deliberate) design specification--a modulo 1024 counter, incremented weekly from 0-1023-- by the military in the original satellites. A kin to the Y2K 2-digit debacle, the designers never dreamt that these systems would be around 20 years later! Wrong, of course on both counts.

2.) On the other hand, if it appear to the public that the GPS fiasco is a non-event, then, indeed, that will "rub off" on Y2K (psychologically) , too.

The "jury" is still out on GPS rollover consequences.

It would be nice to know _more details_ about the State of Texas' "panic" order for prisoner monitors. Did you notice the articles/reports haven't indicated what the _consequences_ have been from using the non-GPS compliant system? Interesting? No?! Why expose the embarrassing details?

Disinformation from self-reporting sources, factors into the Y2K scenario exponentially; everyone is covering for everyone else to avoid inevitable and immutable consequences. Much more at stake: profits; equity; revenues; infrastructure; social and economic life as we know it today.

In the GPS scenario, there will be many unable to reveal they've gone back to sextants and magneto compasses for their lack of foresight. The story will probably be panned and downplayed on a bunch of whining fisher/wo/men.

Either GPS devices work or they don't. Pretty simple. As family, friends and neighbors about real life experiences for the "truth."


Regards, Bob Mangus

* * *

-- Robert Mangus (, August 21, 1999.

Y2K Gardener,

Since I deal is systems that use 64 bits to store dates, 16 doesn't sound that good to me.

I understand what you are saying, but having to pull out an old paper map just doesn't compute to subtracting checks written in 1900 against a balance that didn't exist in 1900.

Could it be possible that the "powers that be" are using this rollover as a non-event? Yes. See, the military will not fail with the GPS rollover, so to them it is a victory. Since GPS was such a smashing success, so will be Y2K. [In their eyes.... at least for now]

But don't forget, it is still early yet. Some ship headed for Boston just might dock in Miami. It is still early.

-- (cannot-say@this.time), August 21, 1999.

Gardener you are a moron, you only need 10 bits to do 1024.

But you are a know it all and have all the answers so 1024 needs 16 bits. So what does 65535 need ?. 64 bits?.

Go back to sleep.

-- Full stop (, August 21, 1999.

Heeeeeeeeelp!!! I'm drowning in the Pollific ocean!

Full Stop - 65536 weeks is what I was suggesting, lamebrain.

Oh - and Cannot-say: If a 10-bit field is signed you'd have 512 weeks, not 1023. I can see the level of computer-awareness that I am up against here.

-- Y2KGardener (, August 21, 1999.

Flint - I don't agree that 20 years ago 6 bits was precious, and certainly not 5 years ago when they were still making faulty GPS receivers.

-- Y2KGardener (, August 21, 1999.


Well, a couple of points here. First, those satellites were designed (and the bitcount selected) somewhat more than 20 years ago. And the choices available at that time weren't anything like today -- I was there. You didn't go to some massive catalog and select among thousands of competing suitable parts, you rolled your own. Adding six bits (or any number, for that kind of application. When you roll your own, there's obviously nothing magic about 2^n bits, and they picked 10) really did add cost and time. And 20 years really did seem like forever, especially in comparison to when they wanted it working.

And finally, that 10-bit limit is in the satellites, not in the receivers. The receivers have plenty of bits, which is part of the problem. The programmers of the noncompliant receivers used all those bits, and didn't include the rollover logic at 10 bits. The 'bad' receivers likely *did* use 16 bits, allowing for 64K weeks, which is of course so long we'd *never* have rolled that one, right?

-- Flint (, August 21, 1999.

Ok Gardener...

Didn't think you knew that much about computers.... So tell me this...

Exactly how many Operating systems do you know of that use 64 bit dates? I'd just like you to name all that you can.

I probably have more IS experience in my little finger than you do in your entire body. Just trying to keep it simple for you.

Is the government/media playing this up? You bet your bottom dollar they are. Why? They don't want a panic. I expect the first panic the Monday after turkey day or there abouts... They are going to try to delay it for as long as they can. Go and read my comments to Mr. Deckers letter. It will tell you just exactly what I have seen re Y2K, but that isn't all of it. Where I work, they were wanting to have the external Y2K audit published on the web page, but couldn't because of what was contained within. Did it have anything to do with the financials? Hell no... it was about HEALTH CARE.

Just how many computer languages do you know? I know 9. what does a 00 mean in ascii? How about an ascii 12 or even a 7? So don't take what I say in trying to keep it simple as the level of computer experience here.

I have worked in getting shuttles up in the air.... have you? I have worked for both local and long distance telephone companies.... have you? I have done engineering programming... have you? I have programmed accounting and cost accounting systems for the feds.... have you? I have programmed human resources.... have you?

If you really want me to get technical.... I will. You up for it?

-- (cannot-say@this.time), August 21, 1999.


Granted you think you are a " brain " and you have a way with words.

Would you, in your vast wisdom, please tell us why the Gps roll over has anything to do with the, shall we say, The Y2k problem? Please cover why a very simple problem ( Gps, buy a new unit ) and the world wide code and embedded challenge should be compared.

Please cover why all us DWGI's should give a big sigh of relief now that the Government has " fixed " all the " mission critical " systems ( 10%? of total systems ) and why we don't need those " non-mission critical systems ", I'd love to hear that!

I know that you have been on a spin cycle over the Navy report, but let's get back to real life.

Got water? Sewer? Power?

A life?

-- CT (ct@no.yr), August 21, 1999.


Oh my God! I never thought I would run into someone who knows the ASCII codes!! I wouldn't dare to take you on where technical issues are concerned.

I'll bet you even know how a hammer works.

-- Y2KGardener (, August 21, 1999.


Yep... and I can program one in 3D....

Still waiting.....

-- (cannot-say@this.time), August 21, 1999.


bbias... gotta refill my drink... Something about a good glass of rum... while there is still rum to be had....

-- (cannot-say@this.time), August 21, 1999.

Does my satellite being out have to do with the GPS rollover? Just curious.. and ignorant... :)

-- Diane (, August 21, 1999.

* * * 19990821 Saturday Y2K Gardener: Check this from the U.S. Coast Guard site... Regards, Bob Mangus P.S.: Hope the snipped HTML source turns out alright here! * * *


GPS System Time will roll over at midnight 21-22 August 1999, 132 days before the Year 2000. On 22 August 1999, unless repaired, many GPS receivers will claim that it is 6 January 1980, 23 August will become 7 January, and so on. Accuracy of navigation may also be severely affected. Although it appears that GPS broadcasts do contain sufficient data to ensure that navigation need not be affected by rollover in 1999, it is not
proven that the firmware in all receivers will handle the rollovers in stride; some receivers may claim wrong locations in addition to incorrect dates.

Some manufacturers have already solved the problem, but some have not.

This is how the precise rollover date is computed: The timescale origin (time zero) of GPS System Time, 00:00:00 UTC 6 January 1980, is Julian Day 2,444,244.500. A GPS Cycle is 1,024 weeks, or 7,168 days, so the first GPS rollover will occur at Julian Day (2444244.5+7168)= 2,451,412.5, which is 00:00:00 UTC 22 August 1999 AD, which is the midnight between Saturday night the 21st of August, and Sunday morning the 22nd of
August, 1999.

Section 3.3.4(b) (page 33) of the ICD-GPS-200, Revision C* (25 September 1997 issue) states that the "GPS Week" count starts at midnight 5-6 January 1980 UTC, and that the GPS Week field is modulo 1024. 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).

Section 2.3.5 (pages 18-19) of the GPS SPS Signal Specification, 2nd Edition, issued on 2 June 1995, repeats the words and warnings of ICD-GPS-200. The GPS SPS Signal Specification may be obtained from the web as an Adobe Acrobat (.pdf) document, at the US Coast Guard's site at gspec/default.htm

Without a GPS Simulator, there is no way for users to test a GPS receiver for this problem. Users are encouraged to contact their receiver manufacturer to determine if their receiver will be affected, in particular if a failure of navigation could put lives or property at risk.

uscgbar.gif (2185 bytes)


Date last modified: Monday, August 16, 1999


* * * RSM * * *

-- Robert Mangus (, August 21, 1999.

Well, he'd show you but you'd have difficulty getting it out of your ass...

-- andy (, August 21, 1999.


Simple answer... NO... Not that I can remember anyway... Doesn't use GPS as they have their own, and they don't use GPS to calculate where they are or where they need to be...

-- (cannot-say@this.time), August 21, 1999.

CT -

That was the whole point of my original question: that GPS and Y2K are being compared and will be compared by the media and the general public.

The technical aspects underlying these two subjects are not even remotely comparable - anyone half way technical can see this. However, the General Public wouldn't know what a bit was if it bit them on the nose, so in their minds "GPS=Y2K=No problem".

Nectar for the Pollies; peace of mind for the sheeple... and that could have been the intention all along.

-- Y2KGardener (, August 21, 1999.

Okay well thanks for the response. We just got it a month ago and this is the first time it has gone out. Thanks!

-- Diane (, August 21, 1999.


Beyond being vaguely similar counter overflow issues, I don't see any relationship between Y2K and GPS at all. I believe that these two rollovers being only a few months apart is pure coincidence. And I don't see any comparison of scale either -- GPS is a few devices, easy workarounds, a small problem at most, while y2k is massive, and everywhere, and takes many more different forms.

So I asked Gardener whether he felt that GPS might scale up more or less similarly -- that is, if 3% of GPS receivers have problems, that may (or may not) suggest that 3% of systems would have serious y2k problems. Personally, I don't see any scaling either. I think GPS is a non-event. I think y2k will be an annoyance people will actually notice who don't specialize in the field.

-- Flint (, August 21, 1999.

Andy.... Usually the first blow is down... so it would have to be inserted.... The it could be pulled out... :)

-- (cannot-say@this.time), August 21, 1999.

Diane... is it DSS?

-- (cannot-say@this.time), August 21, 1999.

Yes it's a DSS

-- Diane (, August 21, 1999.


You should be OK then... They have theirs positioned to service different areas of the country and world. There could be any number of possibilities for the outage... If you have not gotten back your service by the morning, call and ask what is up.

-- (cannot-say@this.time), August 21, 1999.

Okay well thanks for the help. Actually it has cut in a few times since I first posted so maybe it will come back soon. Thanks again!

-- Diane (, August 21, 1999.

Y2k G,

That's why I was, shall we say, talking to Flint. Still looking for why we should be all smiles and grins over a less than 10% system remediation in the Fed. Gov. total 'puter sys. Still waiting with baited breath.

-- CT (ct@no.yr), August 21, 1999.

CT -


I hope my last post clarified my point to some of the others who dived straight into technical issues.

-- Y2KGardener (, August 21, 1999.


You shouldn't be... The 90% that remains has some contact with the 10% that is finished (if it is....). If the 90% doesn't work, you can have one hell of a head-ache trying to get it fixed in 3 hours.

But... the smart question is... what does the government consider "mission critical"? Is it the defense of our country? I sure as hell hope so. If that ties in with parking permits... no problem... park where ever the hell you want.

The question is .... just what is "Mission Critical"? Where I currently work, it is keeping people alive...

-- (cannot-say@this.time), August 21, 1999.

For anyone who doesn't believe the media are connecting GPS to Y2K and blowing it up into a big story, this headline from the BBC:

Bug threatens to lose global navigators The GPS navigation system resets itself in a millennium-style glitch that potentially affects thousands of sailors and pilots.

Here's the story.

-- Y2KGardener (, August 21, 1999.


I'm afraid that " mission critical" means, get the money, we can fake everything else, they can't. Still looking for Flint,

-- CT (ct@no.yr), August 21, 1999.

Ahoooooy Flint!

Maybe's out on the Pollific Ocean with a non-functional GPS receiver :-D

-- Y2KGardener (, August 21, 1999.

I responded a while back, while Diane was gabbing. You might have missed it.

-- Flint (, August 21, 1999.


Please respond again, I missed your take on why the Government Is Y2K O-k with the stats. on total sys. completed todate. Still waiting : )

Guess we didn't need 90% of the system anyway?

-- CT (ct@no.yr), August 21, 1999.


Never known Diane to babble.

Answer Please?

-- CT (ct@no.yr), August 21, 1999.


I've never had any confidence in the government's ability to remediate, or to know where they stand, or to tell us anything meaningful about where they stand. I've posted over and over that our only hope from the public sector is that we can live without most of what the government does. I see no reason to change my mind.

And personally, I believe that we *can* live without most of what government does, and live better than we do now at that. The real difficulty would be if we found ourselves in that position overnight, rather than weaning off the government tit over the course of much longer. But most of what the government does, they do so poorly and inefficiently and inconsistently that y2k might not be that drastic a change from normal operating procedures. Who knows?

-- Flint (, August 21, 1999.

"That was the whole point of my original question: that GPS and Y2K are being compared and will be compared by the media and the general public."

Yes and the media has. The most listened to newsradio station in my area this evening, an hour before the roll-over, was reporting on it and clearly linked it with Y2K. His headline; "The GPS roll-over is taking place tonight, a technical problem just like Y2K."

-- Chris (%$^&^, August 21, 1999.

Let's see: Money spent on remediation of GPS $0.00 +/-

Money spent on remediation of Y2K $1,000,000,000,000.00 +/- and rising fast.

Go figure!!!!

-- Michael (, August 22, 1999.

Michael -

You get it, I get it, and most of the thinkers in this group get it, but the general public doesn't. Nor, it seems, do the media - if they are to be believed.

By the way, I think you underestimated the GPS remediation costs by about $125.00.

-- Y2KGardener (, August 22, 1999.

I don't know the structure of GPS time, but most likely they used whatever was left in a 64-bit, or whatever, counter, after allocating milliseconds(?), seconds, hours, minutes and days.

This sort of thing is common. If you look at the address field of a S/390 instruction, it's 16 bits. 4 bits for a base register, and whatever is left, in this case 12 bits, for the byte address.

But, yes, I do think the public will relate no GPS problem = no Y2K problem. Too bad...

Tick... Tock... <:00=

-- Sysman (, August 22, 1999.


I've never had any confidence in the government's ability to remediate, or to know where they stand, or to tell us anything meaningful about where they stand. I've posted over and over that our only hope from the public sector is that we can live without most of what the government does. I see no reason to change my mind.

You mean we don't need the Fed? Are you some kinda Militia Wacko? Are you far right?

And personally, I believe that we *can* live without most of what government does, and live better than we do now at that.

ROTFLMAO...Sound like my kinda bud. So why are you so polly?

But most of what the government does, they do so poorly and inefficiently and inconsistently that y2k might not be that drastic a change from normal operating procedures. Who knows?

-- Flint (, August 21, 1999.

Or maybe it will be,,,who knows?

-- CT (ct@no.yr), August 22, 1999.

It seems pretty suspicious to me that this incredibly stupid logic error just "happened" to cause problems at this time. The decision (see below) over 20 years ago was not made by the Government to attempt to lul you or anyone else into thinking Y2K will be a non event. If you think about it "the Government and almost every other person IN THE WORLD" was not even aware of the possibilities of problems on computers during the rollover. I knew. A few others knew. But out of all of the people in the world we were like a cup of sand on a beach in Australia.

Where do you get ideas like this? The idea you put out amazes me so much I have a difficult time believing that people actually exist who think like that.,1575,ART-33217,00.html The need for a rollover results from satellites' efficient but peculiar time-tracking. Beginning on Jan. 6, 1980, they began counting weeks in binary code strung out to 10 places or bits, giving the counter a capacity of 2 to the 10th power, or 1,024. At 13 seconds before 7 p.m. on Saturday evening, week 1,023 will end and roll over to week zero. The extra seconds reflect time in leap years that were not counted by the orbiting clocks. As with the Y2K dilemma, the bare-bones counter was born of the need to economize in the early days of computing as a widespread technology, when memory and bandwidth were precious. "We couldn't afford (transmission) faster than 50 bits per second, so we engineered the minimum data content to make a receiver work," said Air Force Col. Neil McCasland, chief engineer on the EOW rollover program. A typical home computer modem sends data about 1,000 times faster. The U.S. Space Command tested one GPS satellite in April, pulling it out of service and pushing its clock forward to make sure it would roll over and continue to function. The Air Force Space Command conducted a similar test with another satellite in July. Both times, satellites operated normally, said Coast Guard Chief Petty Officer Joseph Gispert, who is assigned to the testing effort. "This whole issue is a receiver issue only," Gispert said.

-- Cherri (, August 22, 1999.

Sure it was a conspiracy. That's why it was in the GPS *SPEC*.

-- a programmer (, August 22, 1999.

Moderation questions? read the FAQ