Inaccurate GPS for both iPhone and iPad Pro

All my phones on iOS15 are pinpoint accurate to a few metres

Check your location using Apple Maps and Google Maps,

I suggest you backup the iphone and restore to factory, set up as new without restoring a backup and check Maps again.

Resources

Backup and restore

(1)How to back up your iPhone, iPad, and iPod touch – Apple Support

Unlock your SIM PIN if it has one

(2) Restore your iPhone, iPad, or iPod to factory settings – Apple Support

After testing...

(3) Restore your iPhone, iPad, or iPod touch from a backup

 If the problem remains then arrange a repair

https://support.apple.com/iphone/repair/service

Dogcow-Moof wrote:

It does, but the bottom line is it can only use the information available.

If you're in say a rural area in Wyoming where there is only one WiFi hot spot within miles and it has a registered location of Chicago, depending upon a variety of circumstances when connected to that hot spot it may well show you to be in Chicago.

I think the contention here is that the GPS is likely to be more accurate and should have precedence over Wi-Fi triangulation. I don't disagree, but I'm not privy to Apple's software.

Also - the OP mentioned using Google Maps, which probably has a different way of using all the location data than Apple Maps. I'd suggest looking at Apple Maps to see if maybe it's more accurate.

I found this from Google on their recommendations for improving the accuracy of Google Maps on an iPhone or iPad. They have a recommendation to help with accuracy using Live View.

https://support.google.com/maps/answer/2839911?co=GENIE.Platform%3DiOS&oco=1

Improve accuracy of your location with Live View

1. On your iPhone or iPad, open the Google Maps app .
2. Enter a destination in the search bar or tap a location on the map.
3. Tap Your location  Calibrate with Live View.
4. Follow the on-screen instructions.
5. Your position on Maps becomes more accurate once more data is gathered on your location.

​​​​​​​Tip: Point your phone camera at buildings and signs around you, instead of trees and people.

Part of the problem is the fact that what is colloquially called "GPS" on the iPhone is actually assisted GPS.

Since GPS requires a clear view of multiple satellites in the sky to locate you, and is only accurate to around 16 feet under open sky, assisted GPS uses the location of cellular towers and Wi-Fi hotspots whose owners have registered a location for them to help determine your location.

The down side of this is if a cellular tower or nearby Wi-FI hotspot has been registered with an incorrect location, assisted GPS may have difficulty determining your actual location.

Third party site MacObserver describes the issue well here:

MacObserver: iOS: Assisted GPS and Why iPhone GPS Can’t Be Perfect All the Time

The assisted gps only kicks in when you cannot access the satellites, eg in your house.

You cannot calibrate anything.

If the gps does not work when you are OUTSIDE then

Backup and restore

(1)How to back up your iPhone, iPad, and iPod touch – Apple Support

Unlock your SIM PIN if it has one

(2) Restore your iPhone, iPad, or iPod to factory settings – Apple Support

After testing... If the problem remains then arrange a repair

https://support.apple.com/iphone/repair/service

 (3) Restore your iPhone, iPad, or iPod touch from a backup

VictorHK wrote:

I took out my iPad Pro and iPhone to 3 different places with wifi access. When I disable the wifi and activate personal hotspot, the location spot on both my iPhone and iPad are stable and not far from the exact location. However, once I activate wifi access on both devices, location spot jump again to far away and then back to nearby location, and then jump again. It seems to me that there is something wrong with the wifi module of my devices, not the wifi router.

Anyway, I know there is nothing I can do at the moment. Thus thanks for the info on assist GPS stuff.

It was mentioned that the accuracy of the listing of Wi-Fi locations could be an issue. Also - triangulating a location based on what Wi-Fi (the MAC address supposedly) is not going to be exact.

Also - I believe the gyros have something to do with estimating the location too.

VictorHK wrote:

I took out my iPad Pro and iPhone to 3 different places with wifi access. When I disable the wifi and activate personal hotspot, the location spot on both my iPhone and iPad are stable and not far from the exact location. However, once I activate wifi access on both devices, location spot jump again to far away and then back to nearby location, and then jump again. It seems to me that there is something wrong with the wifi module of my devices, not the wifi router.

No, that is a sign that a or multiple Wi-Fi routers in the area have incorrect location information associated with them.

There is nothing inherent to Wi-Fi that gives location information, it's the location information reported in databases, and often people who own those routers don't bother updating the databases when the routers are moved.

For example, if a business sent in location information then the company moves or the router gets moved to a different office, it's doubtful they update that original information.

Have you done anything to both devices recently such as installing security or VPN apps? To have both devices move away from the expected 10 metre accuracy is very unlikely without action having been taken to change something on both devices.

If you are connectiung by CarPlayto a vehicle with its own gps then discrepancies can occur but you didn't mention that

Because assisted GPS also uses data from nearby WiFi routers which may not be accurate.

For example:

https://www.skyhook.com/submit-access-point

So no, it may not be something that you can resolve.

So if you had restored to factory and set-up with only stock apps and tried Maps like I suggested you would have proved it was software and not hardware.

My iPhones all show me on Apple Maps sitting in my house and the radar icon shows that I am looking to the North out of my house window. I can't screenshot it due to privacy.

My iPhones are as accurate as my running watches.

Admittedly I am under 4 different satellites compared to yours but a 1 to 2 kilometer discrepancy is totally unusual.

Once you try the restore to factory you can come back and let us know you tried it and what the result is.

y_p_w wrote:

Dogcow-Moof wrote:

It does, but the bottom line is it can only use the information available.

If you're in say a rural area in Wyoming where there is only one WiFi hot spot within miles and it has a registered location of Chicago, depending upon a variety of circumstances when connected to that hot spot it may well show you to be in Chicago.

I think the contention here is that the GPS is likely to be more accurate and should have precedence over Wi-Fi triangulation. I don't disagree, but I'm not privy to Apple's software.

Which is why I previously mentioned iPhones and iPads with Cellular; WiFi-only iPads do not have GPS capability.

Well - not sure what else to suggest other than maybe try a different mapping tool like Apple Maps or whatever else might be available in your country. Do you have to use Google Maps?

It does, but the bottom line is it can only use the information available.

If you're in say a rural area in Wyoming where there is only one WiFi hot spot within miles and it has a registered location of Chicago, depending upon a variety of circumstances when connected to that hot spot it may well show you to be in Chicago.