Heads up - global clock reset for all GPS April 6

[TassieTiger]

Heads up guys - every 20 years or so, the gps clock system runs out of numbers and needs resetting.
April 6 is next one...and I’ve been advised that quite a few gps manufacturers do not have allowances within their firmware to allow for the reset...which could see some gps units fail out right, lose accuracy, crash / /reset loops.
I’m lead to believe the top end manufacturers like Garmin etc are all okay.

If you have a gps unit - might be worth a google to see if your unit is protected or needs a firmware upgrade, as there’s only a couple days away before the clock reset.

Cheers.

[pomemax]

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 GPS/GNSS simulator. The requirements for the simulator are straightforward:

Minimum of 4 GPS Satellites simulated
GPS L1 C/A signal type
Possibility to program custom date and time
If you are using any Spectracom GSG-5 or GSG-6 simulator, you can download a scenario to test for the rollover event: SCENARIO FILE

The scenario file starts the simulation at on April 6, 2019 23:25 and runs for two hours. These settings can also be configured on the front panel of the unit by modifying a present scenario, such as GPSStatic.

How to Test For the Rollover

Set GSG transmit power to a suitable level for your receiver (typically -115 to -125dBm)
In the Options – Transmit Power menu
Start the Rollover scenario on the GSG
Select scenario from the scenario list
Press Start
Cold reset the receiver
Allow the receiver to get a fix, and report the correct date and time
As observed on the GSG front panel
Observe the rollover from April 6 to April 7, 2019
Verify the receiver still outputs the correct date and time
Cold reset the receiver
Keep the simulation running
Verify that the receiver can obtain the correct date and time
This verifies the receiver’s capability to obtain the correct date and time in the next GPS epoch without having any previous information from GPS.
Will It Happen Again?

GPS is currently undergoing a modernization program to upgrade the signals with new modulation and data message structures. The newer message types (CNAV and MNAV) use 13-bit binary numbers to represent the GPS week number, so the issue should not occur in the future when more receivers are using the newer GPS signals.
emails some times they are ok

[on_one_wheel]

Reminds me of the Y2K scare... only if this one goes off, loads of fishermen will loose their favorite snapper drop ... midnight gardeners will loose their gold stash burial sights and even worse your car GPS might start giving you good directionfms for a change !

[pomemax]

first thing i thought of the here we go again

[flutch]

sounds like some Y2K bs

[TassieTiger]

If you have a cheap locator that you use out in the middle of no where when hunting - you might want to check it still functions next week before relying on it...nothing more and nothing less. Or - don’t maybe?? If you think it’s a y2k equivalent...then please...please do nothing...maybe I can get a laugh when it’s reported some wanker out the back of whoop whoop didnt ya ke 3 secs to check if his gps unit was compliant with a clock reset.

[Noisydad]

Helll I still use paper maps, a compass and can make and read sundials lol.

[trekin]

Helll I still use paper maps, a compass and can make and read sundials lol.

And use said sun dial as a compass if need be.

[TassieTiger]

I heard that they were currently moving the stones at Stone henge back 15 degrees to allow for the clock change.

[TassieTiger]

My tech department is currently running around like blue arse flies - as are a MAJOR radio manufacturing company, uploading firmware to resolve this coming issue...their tests have shown that THEIR particular GPS systems are not going to cope but their units are + 10 years old.

[Stix]

first thing i thought of the here we go again

The thesis you've submitted above is very impressive indeed...!
It 'appears' to demonstrate your superior acumen on the subject, particularly as compared with Tas...

But patronising questions like "whats the key issue" & comments like ive quoted you as saying here, along with the eye-rolling derogatory tone that accompanies them are probably a bit unnecessary, particularly given the guy is clearly just trying to help his fellow internet pen pals out.

[TassieTiger]

first thing i thought of the here we go again

The thesis you've submitted above is very impressive indeed...!
It 'appears' to demonstrate your superior acumen on the subject, particularly as compared with Tas...

But patronising questions like "whats the key issue" & comments like ive quoted you as saying here, along with the eye-rolling derogatory tone that accompanies them are probably a bit unnecessary, particularly given the guy is clearly just trying to help his fellow internet pen pals out.

Stick mate - all that info that PO wrote - including key issues, is 100% copied from the link. He too was just trying to help.

[Stix]

Ah...sh1t eh..wasnt how it read to me.. ..ok...

Ill read it properly later...

Apologies if thats the case then Pom...

So, there you go...dont sneak a quick look & reply when up on a roof with a chainsaw cutting big branches off a tree eh...

[on_one_wheel]

Helll I still use paper maps, a compass and can make and read sundials lol.

Funny you should say that .. I do use a great app called memory maps that works without coverage provided your phone isn't flat and you've downloaded your area first and have a bushnell backtrack GPS to find places that I mark (yes I'll be checking it) but I don't soley rely on digital stuff when I'm in unfamiliar, remote country.

I have a couple of modern compass calibrated for the southern hemisphere of course and keep maps ... you might like the last not so modern one that I've bought.

1918 VERNER'S' PATTERN MK.VIII PRISMATIC COMPASS

20190404_185745.jpg (146.53 KiB) Viewed 3466 times

I'm also in the early stages of teaching my kids orienteering. I'm getting out with them into the local national park and "discovering" All the great hidden places off the beaten tracks that I found when I was a kid like caves, waterfalls and waterholes.

[TassieTiger]

I’ll never forget when I was 13 and I was at an old shooting shack high in Tas mountains and I told the old bushy caretaker I was going for a shot by myself...as I was walking away he yelled out - “hey, if ya get lost, just come back to the shack”...I replied, “no worries” and today still kick myself....so dumb.

[on_one_wheel]

I’ll never forget when I was 13 and I was at an old shooting shack high in Tas mountains and I told the old bushy caretaker I was going for a shot by myself...as I was walking away he yelled out - “hey, if ya get lost, just come back to the shack”...I replied, “no worries” and today still kick myself....so dumb.

Gold

[Noisydad]

Nice compass OOW! Got some weird and wonderful examples but don’t have one like that in my compass collection.

[pomemax]

bottom line of my first post "emails some times they are ok" some one email me that it aint mine

[Die Judicii]

I dunno,,,,, at the best of times my GPS (when I do actually use it) half the time it doesn't know where it is,,,, let alone guides me.
Some areas just don't work.
I have given up cos I have logged in our address manually several times, and it still doesn't recognize it..

I also know of 3 places where there are signs that say "Ignore your GPS"

[on_one_wheel]

Just checked my backtrack, locations check out, all my marked spots are perfect but my clock doesn't want to correct it's minutes.
It's meant to do that automatically and the minutes can't be adjusted manually.

Not a total loss... but not exactly great.