iPhone SE GPS accuracy problem

Frozen_up_north

While out for a country walk recently, I discovered a serious problem with the accuracy of the iPhone GPS location accuracy. The GPS was basically not working, showing an accuracy circle around 3Km in diameter. We were out in open country, not an underground car park.

The reason for the inaccuracy may be interference, but there is more to the issue:

Returning to the same location with a Garmin eTrex hand held GPS shows an accuracy of 2 to 3 metres. The area of poor iPhone GPS accuracy extends to half a mile, perhaps more.

The above accuracy can be significantly improved by turning on WiFi on the iPhone, even though it's not connected to any WiFi. In the poor accuracy area the circle of error drops to around 65 metres (still very poor), when WiFi is turned on!

A couple of miles away from the rogue area, the iPhone GPS reports an accuracy of 5 metres with WiFi and 10 metres without... This is also with no WiFi connection.

The App I use that gives GPS accuracy in metres is "Ham Square", however the Apple Map App shows the circle in the bad area.

Speaking with Apple, it's apparent they haven't a clue as to why turning on WiFi improves the GPS accuracy, nor why in a bad area it's nowhere near as good as a Garmin!

Anyone else noticed this?

JJ_Egan

Does not WiFi turn on the AGPS on a IPhone ??

Frozen_up_north

JJ_Egan wrote: »

Does not WiFi turn on the AGPS on a IPhone ??

It may have some element of differential GPS via a WiFi connection, but in these instances the WiFi wasn't connected to any router, just turned on.

A friend with an iPhone 6S has just noted the same effect with his phone (5m vs 10m with WiFi on/off).

AndyPK

maybe they are just changing the reported accuracy when WIFI is enabled.

They do give you lots of warnings, that turning on WIFI improves location.

And I can believe it now!

Frozen_up_north

There is an explanation of why turning on WiFi improves GPS accuracy at: http://www.macworld.com/article/1159528/smartphones/how-iphone-location-works.html

However, it doesn't explain the awful accuracy of +/-3Km, which only improves to +/-65m with WiFi on, over a large area of a local village...

cookie365

65m accuracy is abysmal. Get a decent phone.

In open countryside my Android Huawei gives me accuracy to about 4m without needing wifi on.

Terry98

I have used GPS on a Moto G and an app called MapMyWalk and always thought it was accurate.

Here is what they say about iPhones

https://support.mapmyfitness.com/hc/en-us/articles/200117984-iPhone-GPS-Recording-Help

and about Wi-Fi

'Turn off Wi-Fi before starting your workout. Wi-Fi is known to decrease the accuracy of your GPS and also cause network data transfer conflicts.'

Frozen_up_north

cookie365 wrote: »

65m accuracy is abysmal. Get a decent phone.

In open countryside my Android Huawei gives me accuracy to about 4m without needing wifi on.

My iPhone is quite accurate except in one particular village, given that other phones probably use the same GPS chip set, they might suffer the same way.

The link in my earlier post explains how all mobile phones pick up location info from some WiFi sigals in order to obtain a quick location fix, they use data gathered by both phones themselves and Google's Street View camera vehicles...

sharansingh

Sometime it may occurs if phone is not connected to WiFi because WiFi gives correct GPS location with the help of internet.

rhysadams

Are you using something like a Gorilla case? The GPS attenna is in at the top of the phone across the metal band. If you use a heavy duty case, eg for water proofing this could effect it.

Frozen_up_north

I'm not using a waterproof case, the issue seems to be area specific. I am wondering if the local mobile phone site is putting out false location info (if anyone reading this knows if mobile phone masts broadcast their location to assist phone location, it would be useful to know). Another issue could be interference in that area.

Away from that particular village my iPhone SE gives positions to 10m or better -as reported by the "ham square" app.