Sat Nav Doomsday

[Lucan]

I have heard on another forum that some older GPS systems will stop working on 6 April because of a Millenium-type bug. The week counter will roll over to zero, and because GPS systems need to know the correct date the older ones will stop working or just become wrong. Newer ones are not affected. Does anyone else know more about this? I have a GPS built into my 2007 car

This is a link to an article on the subject in "The Register" :-

https://www.theregister.co.uk/2019/02/12/current_gps_epoch_ends/

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.

 

[krus_aragon]

It's news to me, but then I'm not a GPS user.
I've done a quick search of the interweb, but most of the articles I found are news outlets saying "there may be a problem"; nothing from manufacturers about updates or unaffected devices. The advice is the universal refrain "contact the manufacturer".

I had a wander over to Garmin's website (the only GPS manufacturer I can name off the top of my head), but there's no mention of this issue at all on their main support pages. There may be something under the model-specific pages telling you what to do, but they expect me to type in a model number to see those.

 

[dgl]

There was a short interview with somebody from TomTom on BBC R Solent this morning about it, only got the gist of it but it would primarily upset the "time to destination" feature as I believe that (although I could be wrong) that having the correct time is less important it terms of fixing a location only that all the GPS satellites that you are receiving must tally with each other, having accurate time just helps this process and makes it easier from a synchronisation point of view.

They also said there should be updates available to fix the issue but I am not sure if that applies to all devices that are affected.

 

[edwin_m]

From what I remember of studying GPS in the early days, the navigator uses the time and its last known position to work out what satellites should be above the horizon and their approximate Doppler shift, hence which ones to look for. For this reason knowing the time is inherent in being able to function and I can't imagine how a GPS would know its position without also knowing the time.

However if this fails (for example losing time synchronisation, being switched off for a long time or moved a long distance when switched off) it reverts to a wider search which may take longer but as soon as it picks up one satellite it starts getting data on the orbits of all the others. So assuming the new older navigators can read the new time format (for example if it just drops the most significant digit) it may go out of use for a while then re-synchronise.

At least this was the situation in 1989! More recent navigators may have got cleverer in how they acquire satellites.

 

[Basher]

An executive from Tom Tom was being interviewed today on "You and Yours" radio 4 and he explained it.

 

[Busaholic]

Surely the date these Sat Navs will stop working is March 29th?????

 

[DelW]

I have a couple of Garmin handheld GPS receivers (the type with a small monochrome screen showing co-ordinates etc, no mapping loaded) which date from fairly early days of consumer GPS. For quite a few years, the smaller and slightly newer unit has shown location accurately, but been wildly and apparently randomly adrift on date and time, sometimes showing dates as far back as the 1970s - not only long before it was built but I think well before GPS was deployed, at least for public use.
I shall be interested to see if it gets any worse on 6th April, or if the other unit joins it in strange dates and times.

 

[DelW]

I have a couple of Garmin handheld GPS receivers (the type with a small monochrome screen showing co-ordinates etc, no mapping loaded) which date from fairly early days of consumer GPS. For quite a few years, the smaller and slightly newer unit has shown location accurately, but been wildly and apparently randomly adrift on date and time, sometimes showing dates as far back as the 1970s - not only long before it was built but I think well before GPS was deployed, at least for public use.
I shall be interested to see if it gets any worse on 6th April, or if the other unit joins it in strange dates and times.

Following up my own post, it occurred to me to do some on-line investigation. The faulty unit is a Geko 101, and apparently the Geko firmware had a bug that manifested as incorrect dates after January 2010 (longer ago than I'd thought..!). Garmin released an update (to v2.90) in March 2010, but the snag is ... the 101 has no connection port to allow updating. Which is probably why it's no longer available, while the 201 and 301, which have connection ports, still seem to be around. I will try emailing Garmin, but I think the answer will be either I ignore the duff dates (and the time that means it takes to find satellites), or I scrap the unit.

 

[edwin_m]

well before GPS was deployed, at least for public use.

For any use. The one I was involved in fitting to a train was in 1989 and at that point there were only enough satellites for it to work some of the time. Should have been ready before that but delayed due to the Challenger disaster.

Of course there's always the possibility that space debris or some other reason will trigger the disintegration of a satellite, thus creating more space debris that smashes into other satellites in an unstoppable process. This could destroy all satellites and prevent more being launched for some decades until most of the debris has fallen out of orbit. So don't give up on mapreading just yet.

 

[DelW]

For any use. The one I was involved in fitting to a train was in 1989 and at that point there were only enough satellites for it to work some of the time. Should have been ready before that but delayed due to the Challenger disaster.

That is quite early, IIRC affordable consumer sat-navs appeared in the early 2000s. I wasn't sure when the US military might have started using it, probably without any publicity, but if the satellites were few in number in 1989, probably not too long before then.

I'm still a great believer in paper maps though

 

[Lucan]

I'm still a great believer in paper maps though

I believe in both, for different purposes. I am a map fan, with a shelf-full at hand and more in tea chests. They are for examining the landscape (eg I am interested in old battlefields) and for planning routes - for which satnavs are rubbish, at least for the sort of routes I want to take. I plan on a paper map, choose certain waypoints which are probably not on the route that most people (or the satnav by default) would take, and program the satnav to go through them.

Before I had a satnav I would give a map to my 12yo son, tell him the points I wanted to pass through (through Smallville, then the Bigville by-pass, etc) and he would give directions like "Turn left in about half-a-mile onto the B1234". He was quite good at it. With my son no longer at home I regard the satnav as his substitute. A paper map cannot give verbal instructions, and I don't want to look at one while driving. I think I am unusual in not looking at the satnav when I am driving (no need) I just listen to its instructions.

 

[krus_aragon]

I feel I ought to link to this XKCD cartoon on the topic of cheap GPS solutions...

 

[Cumberlandkev]

I have a Tom Tom Pro 5150 and got an email from TomTom encouraging me to use their site to check if my unit would be affected.
It is.
I am now waiting to see if they can provide an update or whether I will need to upgrade. I bought it in 2015 so will be disappointed if I have to upgrade so soon. Not a cheap buy in the 1st place.

 

[DelW]

I will try emailing Garmin, but I think the answer will be either I ignore the duff dates (and the time that means it takes to find satellites), or I scrap the unit.

Indeed, Garmin were unable to help as it's a discontinued model. They did offer a 30% part-exchange discount off the nearest current equivalent, but only from RRP, which just brings it down to around normal retail price, so I think the scrap electronics skip beckons for it. (NB for new readers, this is a bug from 2010, not the one that is the main subject of this thread!)

 

[pieguyrob]

Being a taxi driver, i prefer to use my A-Z. I use google maps if I'm driving to somewhere that I'm not sure about. I presume google maps won't be affected?

 

[bussnapperwm]

Being a taxi driver, i prefer to use my A-Z. I use google maps if I'm driving to somewhere that I'm not sure about. I presume google maps won't be affected?

Nah, as long as it's on an apple or android device it's ok

 

[pieguyrob]

Thats good to know.

 

[HaggisBotherer]

Being a taxi driver, i prefer to use my A-Z. I use google maps if I'm driving to somewhere that I'm not sure about. I presume google maps won't be affected?

I was going to reply that, fortunately, paper maps shouldn't stop working.

(Cue all the usual wails that paper maps are so inconvenient, etc...)

 

[joncombe]

I have a Garmin ETrex H handheld GPS which I think has been out of production for a few years. It says Copyright 2009 when started and the only connector is via a Serial port.

It started having issues with dates a couple of months ago, showing it was July 1999 when it was in fact February 2019. Though it still got the location correct. I reported it to Garmin but got nowhere other than "lots of other people have reported the same issue we'll add your email to the list so we can email when there is a solutions".

However they have issued a firmware update which I have installed on mine and fixes it. It explicitly covers this issue. Though they never sent me an email about it, I found out from another forum.

What I can't explain is why the date went wrong in February because I understood this problem would occur in April.

So at least Garmin have corrected it on this model. I expect they have issued similar patches for any newer GPS with the issue.

 

[Cumberlandkev]

I have a Tom Tom Pro 5150 and got an email from TomTom encouraging me to use their site to check if my unit would be affected.
It is.
I am now waiting to see if they can provide an update or whether I will need to upgrade. I bought it in 2015 so will be disappointed if I have to upgrade so soon. Not a cheap buy in the 1st place.

I am pleased to report that an update was provided and my unit continues to work normally. I was out of the country on the day but checking news reports on my return, it appears that nothing happened to cause a problem! I saw reports of grounded aircraft that proved to be false. We do seem to get our knickers in a twist over these things!

 

[HOOVER29]

A couple of weeks ago I had an email from Tom Tom regarding something about my 9 yr old sat nav not working correctly after a certain date (I deleted the email) & that it was time I upgraded to a spanky new model. I drove through Nottingham city centre the other day, a city where, if not used to it & without a sat nav system then you’ll never be seen again & mine worked ok although it did take its time finds satellites but we’re only talking a minute or so. Hardly life threatening eh. Reckon it’s just a ploy for customers to buy new gear.

 

[Lucan]

I started this thread, and I'm pleased to say that the built-in satnav in my car has worked fine since 6 April, no update involved (or possible). Although an older one, it maybe that it was programmed in a different way from the ones that were supposed to fail. I don't really understand why a satnav needed a date anyway - aren't the satellites geostationary?

 

[robk23oxf]

I saw an image somewhere recently of the GPS on a Boeing 787 which had rolled over to 1999.

 

[edwin_m]

I started this thread, and I'm pleased to say that the built-in satnav in my car has worked fine since 6 April, no update involved (or possible). Although an older one, it maybe that it was programmed in a different way from the ones that were supposed to fail. I don't really understand why a satnav needed a date anyway - aren't the satellites geostationary?

No, the satellites are in low earth orbit so a different set will be visible at different times. They are constantly broadcasting a data stream from which the nav stores the orbital details of each satellite. The nav also keeps track of time when switched off, though not to the accuracy of the atomic clocks installed in the satellites! If it was used fairly recently and hasn't moved far from where it was switched off then it will know which satellites it should be looking for on switch-on.

If it has lost track of where it is or has no current satellite data then it starts from scratch, listens out and as soon as it hears something it can start re-building its picture of the satellite details. This does however take longer.