GPS accuracy during exercise

[wrebble]

Picture says more than thousand words so... picture first.

How can it be that the same lap is measured THAT wrong. It is 1,27 km difference which is BAD. Both lines run on the same road so it can not be just "difference". Step count is the same and also the time. Which one can I trust at all? It isn't the first time it has happened (at least once more). 

FitBit app is up to date. My Versa 2 is up to date.

I started my run the same way: opened exercise - choose "run" - wait FitBit to connect with "connected GPS" - start!

Also the settings are the same when I start the run. I activate "do not disturb" and "always on display".

Am I doing something wrong? Is the app so bad that it does not know how to calculate distance? Is it problem with my watch? I looked into it and it seems this problem has been with you for 3.5 years. Is there seriously no fix?

Anyways, I posted this in "App" section because it seems to be problem with an app. If not let me know.

Moderator edit: Subject for clarity 

[Sjnoelie]

@MarreFitbit, thank you for finaly responding in a meaningful way! 

- Model/brand of the phone you're using. Samsung Galaxy S10 

- OS of the phone. Android 10 

- When exporting the Fitbit GPS data (TCX file), is your distance accurate? Yes

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app? Yes

- As you all are on Android devices, confirm you've done or checked the following requirements. Yes, all access granted, high performance setting (no battery saving), waiting for GPS to connect before starting exercise.

Furthermore I would like to add that the distance inaccuracy is both positive (Fitbit distance larger than actual traveled distance) and negative (Fitbit distance smaller than actual traveled distance). The latter occurs more often for me. I have not yet determined a pattern in the type and magnitude of the deviations.

[wayneramp]

Hello, In answer to your questions.

To further investigate on this, can you all please get back to me with the
following information:



- Model/brand of the phone you're using

Samsung Z-Flip

- OS of the phone

Android 10

- When exporting the Fitbit GPS data
(TCX file),
is your distance accurate?

I have never done this, not sure how to. But I have the same paths with my
Surge or my HR with my Phone on same route without any distance issues.

- When finishing your run/walk on your watch, do you see the same
information (when checking the summary) on the watch than on the Fitbit
app?

The app sometimes shows less than the watch. I did not have issues when I
first used the app.. something changed an update it seemed. It went from
very reliable to nearly useless overnight a few months ago.

- As you all are on Android devices, confirm you've done or checked the
following requirements:



Make sure that your phone can identify your location and can track your
location. For more information, see How do I allow the Fitbit app to
use my phone's GPS sensors?

Confirm
that the Fitbit app can run in the background on your phone and track your
location. For Android (OS 7.0+), make sure you grant the Fitbit app access
to the requested features of your phone. For more information, see What
should I know about using the Fitbit app on my Android phone?


Yes I have done this. It's worth mentioning it seems if I get a text or a
call while the watch is tracking a route it completely loses some of the
map points.. The map will show me running though houses. Once this
happens it will not track properly until it is completly stopped and
started as a new exercise.

I've also noticed while exercising the watch will display "connecting...."
sometimes unlocking the phone and refreshing the fitbit app by pulling down
will help it connect. I may even see the message "device not found"

[cakey21]

@MarreFitbit, 

- Model/brand of the phone you're using. Samsung Galaxy S20 

- OS of the phone. Android 10 

- When exporting the Fitbit GPS data (TCX file), is your distance accurate? Yes, I check it against google maps and upload into mapmyrun. The route distance the map generates is the same as google maps but the distance reported within fitbit can be up to 1.5km out either way - there doesnt seem to be a pattern as to which way it will go.

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app? Yes

- As you all are on Android devices, confirm you've done or checked the following requirements.

• Make sure that your phone can identify your location and can track your location.  Yes, all confirmed
• Confirm that the Fitbit app can run in the background on your phone and track your location.  Yes, all confirmed - have even tried physically opening the app when I start to run and leaving it open in that capacity but still no luck.
• For Android (OS 7.0+), make sure you grant the Fitbit app access to the requested features of your phone.  Yes, all access granted

[Bart_NL]

- Model/brand of the phone you're using: One Plus 7 Pro

- OS of the phone: Android 10 (10.0.5) 

- When exporting the Fitbit GPS data (TCX file), is your distance accurate? no, apparently

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app? yes 

- As you all are on Android devices, confirm you've done or checked the following requirements: Yes

[tecishere]

Posting details of my issue here as I was using an iPhone so its not just an Android problem, however I no longer have my Versa as I couldnt put up with this issue anymore but at least it might help resolution of the issue for others.

- Model/brand of the phone you're using  : Apple iPhone 7

- OS of the phone - 13.4.1

- When exporting the Fitbit GPS data (TCX file), is your distance accurate? Yes

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app?  Yes, the watch and the app said the same, but the Fitbit website was different.

[wrebble]

So since I have no life I looked into the TCX files a bit. 

I went for a run today and Fitbit showed me 6.8 km. The real distance was 8.23 km, so it is a 1.43 km difference. I opened up the XML file of it and looked around. All the coordinates were in the file and nothing was off.

I thought that maybe I can recalculate the distance with coordinates and it came out that I can. So basically I chose 11 random points (10 seconds) and tried to calculate distance between Latitude / Longitude points. So here are the results.

03.06.2020 (Fitbit 6.8 km, actual 8.23 km)

Interval 33:56 - 34:06

Distance via coordinates - 19.566m

Distance from Fitbit calculations - 14.52m

Starting altitude - 72.14m

The altitude ascent / decent sum on interval - 1.66m

So you can see Fitbit has calculated 5.046m / 10sec (25.8%) less than GPS tracks. Calculation from coordinates does not have altitude information on it so the difference is even bigger.

28.05.2020 (Fitbit 8.29km, actual 8.23km // most accurate Fitbit result)

Interval 31:27 - 31:37

Distance via coordinates - 23.892m

Distance from Fitbit calculations - 24.28m

Starting altitude - 69.87m

The altitude ascent / decent sum on interval - 0.47m

I have chosen the same location for calculations. This time Fitbit has calculated 0,388m / 10s more (1,6%) than GPS track. It is pretty good result. Even better, the coordinate calculation does not have altitude information in it, so the difference is even less.

Conclusion

The altitude is most troublesome here. The starting point was the same and the difference was over 2 meters. Also at the same location on 2 different days the altitude ascent / decent sum is different by over a meter which can not be.

Also on the Fitbit app the elevation gain differs from 44,81m to 91.14m (same lap). There is no connection between elevation and wrong distance (see "elevation / distance data" bellow").

GPS can not be the problem. Coordinates are logged in TCX file correctly and they are quite accurate. There are no missing gaps / same coordinates in the file.

It must be some calculation error in watch. There is probably some kind of variable in calculation which f's it up. I did not design the calculation so I do not know what it is. If the watch calculates distance from coordinates plus altitude info, it just can not be that off.

@MarreFitbit If you guys get some ideas from this, great! But I think you guys probably already knew this.

ELEVATION / DISTANCE data (8.2km lap)

Elevation (m)	Recorded distance (km)	Elevation	recorded distance
43.59	8.37	50.90	8.27
44.81	8.2	57.61	7.86
47.55	9.21	64.62	10.12
47.72	10.17	79.86	6.88
49.07	7.74	91.14	8.05

There is no connection between bigger elevation = bigger distance.

If that unknown variable is "stride length" I am going to kill my watch.

[Bart_NL]

Well the same route, both done this week. 

Same versa, same phone... 

First run is a big round (like the second Pic) and a smaller inner round to come upto 5k. 

Second run I don't need to proceed with the inner round to get upto 5k.

 

 

[Bart_NL]

measured on Google maps

This is what Google maps measures as 5k. So without that inner round extra O_O

Using https://www.sunearthtools.com/tools/gps-view.php

I have loaded the tcx file of the larger round (that my versa measured as 5k) into the tool , resulting in a calculated distance of 5.945 km

[jackski]

I've had had have had the same issues. This morning I tracked the run on my Fitbit versa to watch as well as the app on my phone. The app on my phone gave me 3 mi which I think is accurate compared to the watch which gave me 2.35 miles. The funny thing is that once I ended my run in the app it then switched it from 3 mi to 2.54 mi. How can that be?

[naveenb]

I am also facing the same issue. The pace and the distance are way off, around -2-3Kms. It is completely unusable. 

If you can open source the Exercise app, I am willing to fix the issue.

- Model/brand of the phone you're using - Galaxy A50

- OS of the phone - Android 10

- When exporting the Fitbit GPS data (TCX file), is your distance accurate? - Yes

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app?  - Yes

- As you all are on Android devices, confirm you've done or checked the following requirements:

• Make sure that your phone can identify your location and can track your location. - Yes
• Confirm that the Fitbit app can run in the background on your phone and track your location. - Yes
• For Android (OS 7.0+), make sure you grant the Fitbit app access to the requested features of your phone. - Yes

[MarreFitbit]

Hello everyone! 

Update: Thank you all for your reports of this issue. I have forwarded your replies to our Product Team who will be further evaluating these reports. Thanks for the information.

As soon as I have an update, I'll make sure to let you all know. 

[Tjj707]

 Model/brand of the phone you're using. Pixel 2 XL

- OS of the phone. Android 10 

- When exporting the Fitbit GPS data (TCX file), is your distance accurate? Yes,  I have been using Endomondo to track my runs which gives consistent results that align to the expected distance values.  If I take an exported TCX from Endomondo and one from Fitbit using connected GPS into MapMyRun I see the following:

• Endomondo TCX shows the correct distance in both the exercise summary and the route section
• Fitbit TCX shows the incorrect distance in the exercise summary and the correct distance in the route section

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app? Yes

- As you all are on Android devices, confirm you've done or checked the following requirements.

• Make sure that your phone can identify your location and can track your location.  Yes, all confirmed
• Confirm that the Fitbit app can run in the background on your phone and track your location.  Yes, all confirmed 
• For Android (OS 7.0+), make sure you grant the Fitbit app access to the requested features of your phone.  Yes, all access granted

I will add that on a few occasions the distance/pace on my Versa 2 is correct but that is rare.  Like others I have experience both distance higher and lower than expected.  Also as other have done I have tried combinations like no Wifi, no additional Bluetooth connections, manually adjusting stride length and even trying to track then run as bicycling to see if I could eliminate the impact of stride length.  Nothing seems to correct the issue.

I also tried using my work iPhone and experience the same issue:

Model: iPhone 7

Not sure what the exact OS version was at the time but it was 13.x.x

[Brettski55]

-I am using the Google Pixel 4Xl

- OS Android version 10

- When i export the TCX file to a different website the distance is accurate

-when i finish my workout and open the app, the info is the same as my fitbit

-I can confirm i've done all the requirements.

[Brettski55]

As you know from the thread you closed down that the issue still hasn't been fixed. The last thread started in October and still hasn't been fixed so how can we expect Fitbit to fix this anytime soon? Seems to me as well as many other people on here it's time to switch to a different smart watch, one that can actually track exercise like its supposed to. 

[MarreFitbit]

Hello there @Brettski55, thanks for stopping by and for providing with the information requested. We totally understand where you're coming from. The thread started in October was reported with different issues about the GPS that are not related to this topic. It was closed so we can address the issues separately and find a resolution accordingly. 

This specific issue you all have reported with almost the same answer was already escalated and our team is investigating it. We don't have an estimated time frame about when there will be an update, but as soon as I get it, I'll definitely pass it along to you.

Your patience and understanding is really appreciated.

[Brettski55]

No? It's literally the exact same issue that we are all reporting. A lot of the people in this thread were commenting in the previous one. I understand how large the thread was and how bad it looked on Fitbit for failing to fix an issue that had spanned 7 months, so by closing it is a poor attempt to hide the issues that these devices have. I have been trying to voice my concerns with my Fitbit device for a year now and have yet to have a single customer service Rep reach out to me. The only thing I have seen fitbit do in regards to these issues is close that thread. It's easy to say it's been forwarded to the team and they'll look at it, but I guess it's too hard to actually have something done about it. 

[busterandwoody]

Soooooo after receiving my new Versa (following a bricked screen after the latest firmware update) I found the GPS was fine when i first used the new Versa but the firmware was 5 updates behind.

Now i have updated to the latest firmware my runs are widely under what they should be. So cue following this thread! It's one thing after another!! 

Oh and I have followed all the usual suggestions, reset, reconnected to phone etc...

[MaryG-P]

Having the same issues for the past couple of months - seems to get the steps right but the map and distance waaaay wrong. Please advise. 

[wrebble]

@MaryG-P Your problem seems to be related to weak GPS signal. If your map is "way wrong" that means your watch/phone can not locate you. Here we are trying to resolve a problem when GPS signal is strong but the distance is miscalculated.

On your phone go into "Location" settings and review if everything is okay there. There is "Google Location Accuracy" which I highly suggest to enable (if you have not) which means your phone will also use mobile network and other sensors to track your location. If you are in a city you can try turn off "Wi-Fi Scanning" under "Improve accuracy" and see if that helps.

Also watch over your "Battery" settings. Make sure your phone is NOT in "Power saving" mode.

Please look at "How do I use GPS on my Fitbit device?" also. If you still can not resolve your issue please make a new post about your specific problem.

[BornClimber]

@MarreFitbit... All your requested information is below...

NOTE: The Connected GPS *was working correctly until the last Versa firmware update*.

So it may be as easy as just comparing the code change between last firmware and current firmware to see why the assisted GPS is incorrect.
All details and images below.

- Model/brand of the phone
LG G7 ThinQ

- OS of the phone
Android 10
Versa Firmware version 32.70.8.0

Android App Version 3.22.1 (20243506)

- When exporting the Fitbit GPS data (TCX file), is your distance accurate?
My GPS is working fine and Fitbit App is also getting GPS location fine. This is shown by the fact that the run path on the app is recorded correctly.

This is the run from today with incorrect run distance (2.64 mi), but path recorded correctly

And this is the exact same path from 2 weeks ago with correct recorded distance (3.04 mi)

- When finishing your run/walk on your watch, do you see the same information (when checking the summary) on the watch than on the Fitbit app?

Yes... Fitbit App and Versa both give the same summary and both have the wrong distance. But the run path on the map is accurate. But distance is inaccurate! How is that even possible. Even Google maps can show what the correct distance is.

- As you all are on Android devices, confirm you've done or checked the following requirements:

Make sure that your phone can identify your location and can track your location.

Yes... as shown above, the map recorded correctly and automatic location is turned on.

Confirm that the Fitbit app can run in the background on your phone and track your location.

Yes, it does.. and records the map correctly.

For Android (OS 7.0+), make sure you grant the Fitbit app access to the requested features of your phone.
As scary as it is, I have given *every* access to Fitbit on my phone.