iOS12 GPS Accuracy is off?

AustinBike wrote:

Something is not right with iOS 12 and the GPS; it ran fine with iOS 10 and 11 on this phone.

Totally agree - I have had a support case open for a week (having given engineers lots of diagnostics - from an iPhone X) and can see multiple mentions on Twitter.

My example: I run the same 10km route 3-4 times a week. The run is tracked by GPS. Every run for two years tracked accurately until iOS 12. The first map below is iOS 11, the second map is iOS 12, a week apart, running the same route. I am now apparently running random routes through buildings. This is not a limitation of GPS, this is iOS 12 software.

Hi Rob,

I got a replacement for my iPhone X and set it up as a fresh phone - a major hassle. That fixed the problem for a while but the issue came back. It might help, but before you do that, why not try the SIM procedure mentioned above? It doesn't take long and it worked for me and some others on these forums. It might be worth a try just to rule that out. Out of an abundance of caution, I would advise anyone to do it at their own risk though, as some sources say you should shut down first.

Apple's instructions as of today still do not mention turning the phone off here as far as I can see, although that may be their omission/sloppiness:

https://support.apple.com/en-us/HT201337

https://help.apple.com/iphone/11/#/iph3f11fba92

And another discussion's thread as of today seems to say there shouldn't be a major problem. Check it yourself.

https://discussions.apple.com/thread/7468878

Hi tntoofore,

In other threads on these forums some people with older iPhone models resolved their problems by replacing their Wifi/GPS chip-sets and antennas. To confirm your problem is not a hardware-related, I would consider the following (it is a re-paste of my suggestions to others above)

Are you sure you had a genuine A-GPS-based location, rather than a cellular/wifi-only based one?

When I had problems with iOS11, my first step was to use GPS Diagnostic. It is an app that is useful because it shows clearly when your phone has a genuine Assisted-GPS based location, or just one based on Cellular triangulation and Wifi signals. During my jog, I would keep checking GPS Diagnostic to see if it was the app (Motion X in my case) to blame, or if the culprit was the A-GPS system itself.

My solution was the following: (do so at your own risk as some sites advise against SIM replacement while phone is on, ***see note at bottom)

remove the SIM while phone was left on

shut down phone (with SIM left out)

turn on phone (with SIM still out)

insert SIM once phone comes back on

This does not work for some, but it made a big improvement for me, and it worked for others in other GPS threads on this forum. I suspect there was an issue with how the phone registers with cell towers (i.e. the cellular aspect of Assisted-GPS), and resetting via this procedure may have fixed it.

Turning the compass setting to True North, which some recommend, may also have helped.

Just for good measure, I turn location settings off for as many apps as possible, I have none set to "Always" and shut down as many apps, especially other GPS apps, when using a particular GPS app. Also, I always stand stationary until I am sure I have an A-GPS-based location, before starting my jog.

***Out of an abundance of caution, I would advise anyone to do the SIM procedure at their own risk, as some sources say you should shut down first. Apple's instructions as of today still do not mention turning the phone off here as far as I can see, although that may be their omission/sloppiness:

https://support.apple.com/en-us/HT201337

https://help.apple.com/iphone/11/#/iph3f11fba92

And another discussion's thread as of today seems to say there shouldn't be a major problem. Check it yourself.

https://discussions.apple.com/thread/7468878

tntoofore

75% for 4 satellites on GPS Diagnostic is a good reading.

If possible, you should keep Wifi on, as it helps, like cellular, to improve the accuracy of your GPS-based location.

I think Bluetooth would more likely be the culprit when inside a car. (there are reports of it not working in iOS12 https://appletoolbox.com/2018/09/bluetooth-problems-with-ios-12-how-to-fix/ ). I don't use my iPhone for car navigation and prefer to keep Bluetooth off as it doesn't affect GPS accuracy when walking/jogging. Also turning Bluetooth off via Control Center only disconnects you from Bluetooth networks temporarily rather than turning off the Bluetooth receiver completely, How to really turn off Bluetooth and Wi-Fi in iOS 11 - CNET

pandahill

Thanks I will check it out. I think the reporting feature is mainly for faults with Apple Maps such as wrongly named or non-existing buildings. I have sent feedback via that before (and seen no corrections yet!). Any way of letting Apple know about its sub-par GPS functions is worthwhile. I have also sent feedback via this Feedback - iPhone - Apple

I have an iPhone X and use GPS intensive apps (Strava or MapMyRun) to track 10km runs several times a week.

Since the iOS 12 update the GPS has been similarly inaccurate and unstable in every app including Apple Maps.

This has produced nonsensical records of my runs (route going through buildings and 10-15% out on distance).

I am absolutely furious because it is screwing up all my stats and speeds and has been going on for a week now.

I opened a support case last week and was asked to spend nearly an hour creating lots of diagnostics for Apple.

This included a screen recording of GPS in Apple Maps jumping all over the place while I went for a simple walk.

Despite this, I've had no feedback, no resolution, and no ETA - but I now have a £1200 phone that can't do GPS.

Undoubtedly iOS 12 and for this to be happening on a vanilla iPhone X doesn't say much for Apple's test quality.

You're in Hong Kong, land of the high rise and urban canyons. You can expect poor or unpredictable GPS performance in some city environments caused by restricted view of the satellites so reduced accuracy or no fix, and multipath errors when buildings reflect the signals, causing incorrect position fixing.

Branta_uk wrote:

You're in Hong Kong, land of the high rise and urban canyons. You can expect poor or unpredictable GPS performance

And I'm in central London and have the same issue. Also the original contributor, like me, reports this as occurring after the update to iOS12, so I expect that they, like me, had no problems with GPS performance prior to this update.

I stand by my comment about reception conditions, blocking, and interference. If you can demonstrate the problem in an open environment with a clear view of the sky (at least 60-70% of the 180 degrees sphere above you is visible and unobstructed) then you may have a problem in the device, and my advice would be Contact Apple Support and get the hardware checked.

Please also remember iPhone doesn't do "pure" GPS, and satellites move across the sky. It does Assisted GPS, which can also derive some fixes by less accurate methods such as cell tower triangulation when necessary. If the satellites have poor visibility at some moment your fix may be determined by land based methods giving significant loss of accuracy. 30 minutes later all the satellites have moved, and from the same location there might be perfect visibility of enough satellites to calculate a fix within a few metres.

Thanks Austin. I'm still seeing Apple Maps GPS location unstable, incorrect and variable, even when stationary. It just moves my position around wildly, without any pinpointing. This is true even after rebooting my phone (iPhone X).

What did you test to be sure Strava is working, as that is my killer app for GPS and all my stats are getting torched this past week or so, which is really demoralising and enough alone to move away from using Apple devices ASAP.

My Apple Support Case has been open for over a week, I've had 4 different senior representatives, promised updates repeatedly not occurred, and despite sharing huge amounts of diagnostics, the engineers reverted with the question "does it happen all the time" after 5 days (something they already had recorded), which I'm sure was to buy time.

This has been an all-time low in years of buying Apple products (iPhone, iMac, MacBook, iPads, Watch etc). I'm not even a fan boy I just believe for the price you get the peace of mind of reliability of hardware and ability to perform your desired use cases, which is why this matter introduced since iOS 12 is so thoroughly depressing and frustrating.

I have the same issue in Australia. iPhone6 running iOS12

It is an issue across all my apps that use GPS.

GPS worked perfectly under iOS11.

When walking in open space the GPS would seem to refresh/connect infrequently with maps open.

The location arrow in the status bar would switch from solid (GPS active) to hollow at maybe minute intervals

So much so that while navigating I could drive 3 blocks past a turnoff before the GPS navigation realises to tell me to turn around.

Walking is the same you would easily be 20-40m away from the location the GPS is reporting.

Your location would stay static and then refresh every minute or so, exactly the same as Rob2775 reported with his running eratic route.

Apple please fix.

Austin,

I thought Google services, including Google Maps are banned in China, aren't they?

Google said on Tuesday it has made “no changes” to its mapping platform in China, denying an earlier media report that claimed it was re-launching the function in China, where many of its services are blocked.

https://www.reuters.com/article/us-google-china-maps/google-to-relaunch-map-serv ice-in-china-nikkei-idUSKBN1F42GD

"Neither Google Mail nor Google Maps work in China, so although you can download your maps before coming to the country, there’s no guarantee that your Google Maps will be current or even show the right directions, so be careful."

https://www.thechinaguide.com/preparation/maps-and-navigation

"The block is indiscriminate as all Google services in all countries, encrypted or not, are now blocked in China. This blockage includes Google search, images, Gmail and almost all other products

https://en.wikipedia.org/wiki/Google_China

That might explain why all your other GPS apps worked except Google Maps when in China.

As for the issues in other locations:

Are you sure you had a genuine A-GPS-based location, rather than a cellular/wifi-only based one?

When I had problems with iOS11, my first step was to use GPS Diagnostic. It is an app that is useful because it shows clearly when your phone has a genuine Assisted-GPS based location, or just one based on Cellular triangulation and Wifi signals. During my jog, I would keep checking GPS Diagnostic to see if it was the app (Motion X in my case) to blame, or if the culprit was the A-GPS system itself.

My solution was the following: (do so at your own risk as some sites advise against SIM replacement while phone is on)

remove the SIM while phone was left on

shut down phone (with SIM left out)

turn on phone (with SIM still out)

insert SIM once phone comes back on

This does not work for some, but it made a big improvement for me, and it worked for others in other GPS threads on this forum. I suspect there was an issue with how the phone registers with cell towers (i.e. the cellular aspect of Assisted-GPS), and resetting via this procedure may have fixed it.

Turning the compass setting to True North, which some recommend, may also have helped.

Just for good measure, I turn location settings off for as many apps as possible, I have none set to "Always" and shut down as many apps, especially other GPS apps, when using a particular GPS app. Also, I always stand stationary until I am sure I have an A-GPS-based location, before starting my jog.