LeroyPatrol (09-05-19),Tiny (18-02-19)
I read the following on Slashdot, about changes to the US GPS network.
Anyone else know anything about this, or what effect it may have ?
Older satnavs and such devices won't be able to use America's Global Positioning System properly after April 6 unless they've been suitably updated or designed to handle a looming epoch rollover. GPS signals from satellites include a timestamp, needed in part to calculate one's location, that stores the week number using ten binary bits. That means the week number can have 210 or 1,024 integer values, counting from zero to 1,023 in this case. Every 1,024 weeks, or roughly every 20 years, the counter rolls over from 1,023 to zero. The first Saturday in April will mark the end of the 1,024th week, after which the counter will spill over from 1,023 to zero. The last time the week number overflowed like this was in 1999, nearly two decades on from the first epoch in January 1980. You can see where this is going. If devices in use today are not designed or patched to handle this latest rollover, they will revert to an earlier year after that 1,024th week in April, causing attempts to calculate position to potentially fail. System and navigation data could even be corrupted, we're warned.
LeroyPatrol (09-05-19),Tiny (18-02-19)
Look Here -> |
Y2K was going to break the world they told us, will be interesting to see what happens with regards to this rollover, if anything.
Wonder how many GPS's are still in use with firmware that old it hasn't been patched for this issue?
Wouldn't be too many I'd imagine.
I remember hearing some gossip a while ago about the new network protocols the GPS systems will be using breaking all the older GPS's.
Apparently the original legacy frequency will still be broadcast & the only problem will be the older GPS's won't be able to take advantage of the extra features .
The government is in the process of fielding three new signals designed for civilian use: L2C, L5, and L1C. The legacy civil signal, called L1 C/A or C/A at L1, will continue broadcasting, for a total of four civil GPS signals. Users must upgrade their equipment to benefit from the new signals.
Thanks for the warning, looks like it should not actually be a problem & Sat Nav manufacturers have been aware of this since the first epoch rollover in 1999.
A check at Garmin resulted in the following warning or nonevent notice for Aviation GPS
I would think, therefore that their GPS firmware in all devices is capable of the rollover in time stamp.
Aviation Alerts and Advisories
Service Advisory 1905: GPS Rollover
JANUARY 28, 2019 SERVICE ADVISORIES
PRODUCTS AFFECTED:
All Garmin aviation products are affected.
ISSUE:
On April 6, 2019 the week number broadcast by the GPS satellites will roll over. As a result of this event some GPS devices may recognize an incorrect date when powered on after April 6, 2019.
After extensive testing, Garmin has determined there are no known issues with Garmin aviation devices as a result of the April 6, 2019 rollover date.
Further testing is underway to check for future GPS time and date issues.
PILOT ACTION:
No action is necessary.
I suspect that other major brands won't have a problem either.
Cheers, Tiny
"You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
The information is out there; you just have to let it in."
Jma (18-02-19),LeroyPatrol (09-05-19),Lofty2 (18-02-19)
some more info for those with other systems that rely on Satellite time stamps.
What’s the Key Issue?
The Global Positioning System provides accurate timing information to many of our critical systems – power grid, communications, financial markets, emergency services, and industrial control to name a few. It also includes the ability to transmit the proper date and time to a receiver by supplying the receiver with the current week and the current number of seconds into the week. This allows the receiver to translate the date and time into a more typical format – day, month, year, and time of day.
However, the field that contains the week number is a 10-bit binary number. This limits the range of the week number to 0 – 1023, or 1024 total weeks.
GPS week zero started January 6, 1980. The 1024 weeks counter ran out and rolled over on August 21, 1999. The week counter then reset to zero, and it has been recounting ever since. The next time the counter will reach week 1023 and rollover to zero is on April 6, 2019.
Party Like It’s 1999? Not
Receivers must properly interpret that week number as the correct date, not 19.7 years into the past or future. To do this, receivers use various methods to ensure that they are providing the correct date. One common method is to use the firmware date as a reference. This works well if the receiver is new or is receiving firmware updates. It is also possible for the user to modify this reference date in some receivers.
Another way is to shift that 1023 window with reference to some firmware or manufacture date within the receiver. Using this method, the problem could occur, but at a different date and year than the actual GPS rollover date.
Should I Be Concerned?
Because this it is the second time the GPS week rollover will occur, many receiver manufacturers have prepared for it, and newer receivers will continue to operate without issue.
You should be concerned, though, if either of the following applies:
- Receiver has been fielded for more than 10-15 years without firmware updates
- Receiver is a core component of a critical timing system – ask yourself – what is the impact to my system if the GPS receiver stopped operating or put out wrong GPS or UTC information
In these cases, we want to verify that an issue will not occur. At a minimum, we recommend consulting your receiver manufacturer to confirm that the issue has been fully tested and will not occur. Many manufacturers have already issued compliance statements, and we expect them to continue to do so over the next year, up until the event occurs. To be sure that your system will not experience any failures related to this issue, it is possible to test for this event using a . The requirements for the simulator are straightforward:
Cheers, Tiny
"You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
The information is out there; you just have to let it in."
Lol, hope my el'cheapo Chinese device's Roms are equipped to handle this rollover...if not my Garmin might be the only one I own that still works
Now I know why I get lost all the time, My GPS is 1024 weeks out of date...........and here I was thinking it was because people kept telling me to get lost.....
I'm out of my mind, but feel free to leave a message...
Tested all my devices, all of them still connect to satellites ok after this epoch rollover.
The oldest one, a Garmin GPS 60's last firmware update was dated 2006 & it still works ok.
Victorian Country Fire Authority have lost all GPS function in their Tait radios and some other devices.
A firmware upgrade is available to fix it but there are several thousand radios requiring the upgrade, which can't be done OTA.
Tiny (15-04-19)
My old Garmins are all good.
Cheers, Tiny
"You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
The information is out there; you just have to let it in."
Apparently not entirely without some adverse results:
Y2K of GPS causes glitch grounding Bureau of Meteorology weather balloons
A GPS clock rollover that experts predicted would have little impact because of years of advance notice has caused the grounding of the Bureau of Meteorology's (BOM) weather balloons.
........The ABC also contacted aircraft manufacturer Boeing which confirmed that the GPS clock rollover caused "a limited number of 787 airplanes" to display the wrong date, causing them to be temporarily grounded in China.
Surprising Tait products were affected by this, they've been around for a long time.
Jma (15-04-19)
They must be old!
My old Garmin ETrex Vista hand-held is 11 years old & hasn't had a software update since 2012. Maps on it's SD card have been updated though.
When I turned it on after the epoch it showed a date of Feb 1999 for about 15 seconds until it had logged into enough sats, then it flicked straight to the correct Date & Time.
Last edited by Tiny; 15-04-19 at 07:13 PM.
Cheers, Tiny
"You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
The information is out there; you just have to let it in."
The CFA radios are TM9100 models.
The GPS receivers in them are different to a dedicated GPS handheld or car navigator.
The issue is that CFA use proprietary firmware in the radios, so they needed to roll out an update long before now.
Perhaps they were thinking this wouldn't affect them, but it has.
The radios are all due for replacement from next year anyway.... most likely going back to Motorola.... but, we digress.
so, did the world fall apart, once again, from this?
Do we still know where we are?
To tell the truth, I've been to busy fallowing my nav's directions to know.
__________________________________________________ __
Statistically, if you wait long enough, everything will happen!
I used my Tom Tom GPS when coming up north last week and it was not working well at all.
It was having a LOT of trouble finding the satellites and when it did it only seemed to be able to lok on for 30 sec to a min then lost them again.
I got an email from Tom tom it may not be update able which I am extremely dissapointed about as the thing was given to me and has a LOT of sentimental value.
Haven't had a chance to try and update it nor see if it was a one off but I doubt it. Never had any trouble with it like that before.
I would guess it's about 6 yo , maybe a little more. I hope it can be updated because I would not like to have to put the thing in a drawer.
Anyone else had any problem with normal GPS nav units?
No wonder I get lost on the way from the lounge room to the kitchen! And here I was thinking that it was SWMBO calling out to me to do something for her.
I'm out of my mind, but feel free to leave a message...
Powered up a Garmin 255 from 2007 (12 years old) and its working without issue. Quick lock onto satellites and claiming 4m accuracy.
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