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Discrepancy Detected In GPS Time
jones_supa writes that on Tuesday, 26th January, Aalto University's Metsähovi observatory located in Kirkkonummi, Finland, detected a rare anomaly in time reported by the GPS system (Google translation). The automatic monitoring system of a hydrogen maser atomic clock triggered an alarm which reported a deviation of 13.7 microseconds. While this is tiny, it is a sign of a problem somewhere, and does not exclude the possibility of larger timekeeping problems happening. The specific source of the problem is not known, but candidates are a faulty GPS satellite or an atomic clock placed in one. Particle flare-up from sun is unlikely, as the observatory has currently not detected unusually high activity from sun.
...disregard it if it continues to exhibit faulty timing.
'course, there really should be a way to correct time in a GPS satellite, if only to avoid making them completely disposable (then again, maybe there is a mechanism to correct/self-diagnose timing issues on-board? One would think/hope so...)
Quo usque tandem abutere, Nimbus, patientia nostra?
It's a hacker or NK trying to start a war.
I think the clock went through a pocket of dark matter and the time dilation caused the time discrepancy.
They where checking if they could skew the accuracy of GPS and if anybody would notice when they did. Oops, somebody noticed.
Well, that's my theory.. Don't ask me who "they" are because I left my tinfoil hat at home today.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Y'heard it here first! Don't tell me I didn't tole ya!
Going back in time by a mere 13.7uS doesn't seem very exciting though.
It's about to get exciting, folks!
Sounds like the aliens are preparing for an invasion.
I use a GPS-DO to generate a lab reference 10.000000MHz signal. 13 microseconds is huge, but if it only happened once, it'll buff right out. But if it wasn't supposed to happen, then you gotta find out why. Maybe that intern didn't crimp his SMAs properly.
Was systemd installed on any of the satellites recently? Maybe it was installed unintentionally, while upgrading the satellite from Debian 7 to Debian 8?
Damn, my $80 dash cam uses GPS time. I'm screwed.
It's obviously a glitch in the Matrix. Something's changed!
13.7us means about 4km of position error, so yeah, a big deal.
http://www.navcen.uscg.gov/?Do...
Is Cathrine Zeta-Jones at it again?
Surely if you have more than a couple of satellites in view it will discard the 13.7mS one as a multipath. The chance of it actually giving you a reading thats off by 4km would be quite low I'd say
Mr. President, they are using our own satellites against us and the clock is ticking.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
that should be a fun detective story to watch unfold.
I wonder if anybody else noticed.
Surely NIST boulder or the Naval Obs in Washington, or greenwich should have seen it.
Unless it was confined to a part of the constellation on the other side of the planet.
Most likely a h/w failure, seems unlikely somebody has figured out to hack into the system.
This is the second time a bug in the firmware of Motorola Oncore GPS receivers have manifested itself. There is a bug relating to a 32 bit wide bitmap, and DoD just took the GPS satellite numbered 32 out of the constellation and that seems to be the cause. I have data for two such receivers showing the anomaly and for one different receiver seeing no trouble at all.
Poul-Henning Kamp -- FreeBSD since before it was called that...
A small black hole passed through the path of satellite beam in front of the receiver.
Has the HMS Devonshire been seen lately? Someone should check Elliot Carver's secret lab for evidence...
What the hell are you driving, the Millenium Falcon?
This is why there's redundancy built into the system, more satellites than are strictly needed for operation. If one's clock goes out-of-spec, you notice that it's not agreeing with the rest of the constellation and drop it from your sources. If it's a transient glitch it'll come back in-spec and come back into use, if it's a permanent problem they decommission it and schedule a replacement. Redundancy makes the difference between a major crisis and a minor annoyance.
"(...) reported a deviation of 13.7 microseconds. While this is tiny (...)"
Tiny ? It's huge.
If such an error occurs every hour, the total accumulated error would be more than 7 seconds. It's tiny if you look at it individually (well, not so tiny - your 2GHz CPU clock has a period of 500ps (picosseconds) - that's 0.0000005 microseconds).
The atomic clock period (based on Cs-133) is 108.78278 picosseconds. So this is very very large.
Alvie
Lots of folks on the time-nuts mailing list have GPS-based systems to maintain not only precision time, but also precision frequency standards, and many of them saw and recorded this one.
Millenium Falcon? Pfft. Doesn't even hit Ludicrous Speed, let alone go plaid.
Spaceball One would smoke that thing.
But it's aliens
Have you ever fallen asleep at the keybhanusdiog?
Reading this, I really feel like I'm living in the future:
"The automatic monitoring system of a hydrogen maser atomic clock triggered an alarm which reported a deviation of 13.7 microseconds."
-Styopa
Surely if you have more than a couple of satellites in view it will discard the 13.7mS one as a multipath. The chance of it actually giving you a reading thats off by 4km would be quite low I'd say
What if you're coming out of a tunnel or out of a parking garage?
Do not look into laser with remaining eye.
My son borrowed the MF. I'm going to have to have a talk with him. He hasn't been his old self lately, its like he's joined some kind of cult. Well, I'm sure it will go ok.
Here’s the problem:
Engineers and Scientists have constructed a model of time based on it being a fluidic thing.
Time has traditionally been thought of as being a wave like function, analogizing the flow of time to the flow of a river or stream.
The concept had been simplistic: Sometimes time flowed faster and sometimes it flowed slower.
Einstein’s relativity helped predict that flow.
Accordingly, Computer Scientists have calculated GPS time based on Einstein’s relativity adjustments – erroneously.
The problem, in a nutshell, is that time is discrete, and the error detected with the GPS system is a glitch outlining the discrete nature of time.
Time is best thought of as a sequence of events happening in a predictable fashion and documented from an observer’s perspective.
In its most simplistic fashion, it is the diurnal cycle and the notation of those days through a system called a calendar.
At the atomic level, it’s the precise number of vibrations of a cesium atom which happens at a predictable rate which are then used to create the definition of a second.
For a photon, it’s the constant and highly predictable duration it takes a single photon to cover roughly 186,000 miles.
Time, you see, is a discrete passage of events, but has consistently been calculated as though it were a fluid and changing thing.
GPS Programmers actually INTRODUCED error through their calculations based on a very simple misinterpretation of Einstein’s Theory of Relativity by regarding time as an analog function of nature rather than a discrete function of events.
It’s my theory that we are seeing our first direct evidence of a holographic universe.
And that these Finnish researchers are picking up transmissions of GPS signals from alternate realities.
And the map issues Apple and Google have been plagued with are yet another example of these issues.
When the atomic clocks in GPS satellites have a discrepancy, you don't report a discrepancy. You report you have done some experiments that suggest faster than light travel across some 30 km apart in the Swiss Alps. By the time they track it down and attributed to some discrepancy in some atomic clock, you got your headlines, the 15 minutes of fame.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
I live near an airport. I like to remind people that X years ago people would be in awe of that the same way we muse about "spaceports" of the future.
God is messing with space time getting ready for the rapture!
Chuck Norris did some push ups so aggressivly that in contrast to his normal work out he liftet his body upwards and did not push the earth down,
thus generated a gravitational wave hitting the gps satellite.
The other explanation is:
It is a black hole and we all are doomed.
Clock speeds are sensitive to the structure of the gravitational field. Maybe other aspects of the Universe.
GPS times have all sort of noise. Some geophysicists use this "noise" to figure things like the atmospheric temperature and density. The GPS signal wavefront bend slightly then. You can tomographically invert for spatial location of the travel time anomalies to locate temperature and density changes. There are papers on this every year at the American Geophysical Union meeting.
Microsecond size anonalies are huge and may have more mudane causes like software.
That's the only way to make sure! ... that it's no longer in the orbit...
It has been rumored that the "public" GPS in the region over Syria started having some precision issues around the same time that Russia started bombing Syria.
The US DoD does not use the "public" GPS; their precision tends to stay spot-on, and is much higher than what the "public" GPS provides.
I could just feel it.
It could also be a prelude to a military action someplace. Changing the atomic clock results could completely disable the accuracy of any weapons that depend on it.
I would not be surprised to see a sudden major war involving the United States, Russia, China, or other major power.
It's not a problem unless all four corner days are off and thus the four corners of the cube.
Would create this sort of point discrepancy.
The activation of the Large Hadron Collider with full power this past year has ripped a hole in the space time continuum and has been jumping the planet forwards in time by nanoseconds, now milliseconds. If the rift is not contained it will eventually grow exponentially from seconds, minutes, hours, days, months, years, centuries, millenniums to eventually eons, and may forward us in time past the moment of when Sol had collapsed killing us all!!!
An elite team belonging to the Impossible Mission Force has broken into some high security facility where the only exploit vector was the clock to the mainframe computer which manages the fingerprint pads, voice recognition, iris scanning, and DNA testing of some corporate entity...
Either that or it's Oceans Fourteen being directed by James Cameron and he's gone a bit overboard on the real life sets again...
Aliens. Wait, Bigfoot. WAIT, ALIEN BIGFOOTS!!!!11!1!!!1
Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
The troublesome bird was SVN-23, one of the oldest GPS birds, launched in 1990!
It was the last of the Block IIA birds, and had an expected 8 year lifetime, which it beat by quite a few years!
It featured a combination of cesium and rubidium clocks -- two of each. Now decommissioned -- http://www.navcen.uscg.gov/?Do...
Read more of this bird's interesting history -- http://www.schriever.af.mil/ne...
Wacky Delly did it 20 years ago!
https://www.youtube.com/watch?v=-b_polwFplI
It looks like the actual problem was a bad data upload; Specifically, some satellites were transmitting incorrect parameters for UTC offset correction. https://www.febo.com/pipermail... is the posting from a gentlemen at Meinberg that has the details. http://www.usno.navy.mil/USNO/... has more information about the time offset parameters (A0 and A1) and how they interact with GPS and UTC time.
According to another message (https://www.febo.com/pipermail/time-nuts/2016-January/095686.html), PRNs 2, 6, 7, 9, and 23 got hit. It is interesting to note that the satellite that was taken out of service this morning (PRN 32) is not in this list. It looks like the decommissioning of PRN32 was quite possibly scheduled (see http://gpsworld.com/last-block...), and even if not, a failure of that specific satellite could not have caused multiple satellites to start broadcasting incorrect offset data.
I'm really looking forward to the postmortem on this.
(source)
There was no glitch in GPS time, but one satellite was transmitting bad GPS/UTC difference information.
GPS time is not quite UTC time. Each satellite transmits the necessary translation factors along with other housekeeping information. One factor is the number of leap seconds and the time of the next change. The other is a linear function (with an offset parameter A0 and a slope A1) that specifies a precision offset.
Normally, A0 is tiny, but one satellite broadcast a bogus A0 value of 13.7 us. Any receiver that believed it would then jump its UTC output by the same amount, leading to the glitch.
A receiver that used GPS time (all GPS receivers have an option to not apply UTC corrections to their PPS output) would not have seen a glitch.
Be veery careful of your electromagnetic transmissions!
Ha ah
And if you're measuring the distance that radio signals travelled, that's a whopping 4 km.
Is this one of those "that's funny" events that lead to world shattering discoveries?
Or just a bug...?
working in the securities trading industry, 13.7 microseconds is considered HUGE, that is 6 micro seconds longer than our 99.9% latency numbers last week when we generated 24 billion messages in 6 1/2 hrs.
Just patted a passing bird(in orbit)
I used to constantly search my local bookstores for any new stories on our giant metal protectors, but it seems this flavor of military SF has all but disappeared.
13 us in GPS is a pretty big or small misalignment, depending on how you look at it - some 4.1 Km. Definitely enough to upset systems like GPS guidance. - Of course most of the time there is plenty of satellite redundancy..
Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..
Galaxy Quest holds the answer to the GPS time problem. Omega 13 actually rols back time 13.7 milliseconds.
-Eric
You need at least 3/4 to give you a position as you use the time signals to give the distance from each satellite and give where they intersect. One radius will be 4km different than it should be. That means they'll intersect in completely the wrong place. You're guaranteed it'll be off. 4km is worst case but it's more likely to be half that. 2km is still pretty badly out though. You'd need twice as many satellites to cancel it out really.