Connected GPS Pace and Distance is Inaccurate

[DanielMena9]

Went on a run today with my Charge 2 on one wrist and Charge HR on my other wrist. Also had RunKeeper to measure my distance. I started my run with about the same number of steps on both FIT devices. 

After the run, my Charge HR had almost 2K more steps than my Charge 2. In addition, my GPS map on FitBit matched my Runkeeper map which is about a 3.5 mile run BUT FitBit pegged the same route as 1.73 miles >.> 

Why doesn't this device work as advertised? I really like the design and feel of Charge 2 but if it can't do its job accurately, all is for not and I will be shorting FIT as it appears to be a widespread issue (I have maps and photos if someone from FIT wants the data).

Moderator Edit: Edited thread title.

[tbbmomof4]

I run the same 4 mile route very often. I have sent multiple screen shots to Fitbit to show problems with GPS tracking. No one can seem to figure it out and at this point I am just frustrated and going back to my old GPS watch and syncing to Strava. I have never had a problem like this before. I like to compare segments.  I have 6 runs over the same route with the Charge2 and not one has even a similar map or distance. Strava cannot even discern they are somewhat similar. Very disappointing. Fitbit keeps offering the same solutions that do not work. The Charge2 does not have the features advertised. Guess I'm stuck with this unit for a while since I have had it for 2 months. Unfortunately, I spent a month back and forth with support.  Not impressed.

[Glennbest]

Tbb,

You are not stuck with the unit. The 45 day period is only a change of mind policy, you are still covered by the 12 month warranty. Simply contact support and ask for a refund as the unit is not performing correctly and according to all the evidence online it is a design defect.

[SunsetRunner]

@tbbmomof4 I am sure this is not a solution but if you export the runs from Fitbit as tcx files, you can import into Strava and in there it will show the correct summary. Same frustration as you. 

[tbbmomof4]

Thanks or the tip, but I need to lighten the load on uploading data. Also,
Fitbit informed me that even though I have gps connected, they still
calculate distance on a step count, not vs the mapped distance. May have an
option to this pain. I have an Orangetheory Mio heart rate wrist band and
will try it with my old trusty Garmin gps watch tomorrow.

[Glennbest]

Hi tbb,

That's rubbish, the charge 2 doesn't use steps to calculate distance in connected gps mode, if it did it wouldn't show connection to the phone. People have tried different stride lengths to try and correct the error but it changes nothing. Stop believing customer support, they have no idea what they're talking about in my experience.

[Colinm39]

@tbbmomof4to add to @Glennbest post this link is Fitbit's definition of how Connected GPS calculates distance... It doesn't use steps for distance, only if the GPS connection fails or takes some time to start after you have activated the activity..

[Rollerskier]

What kind of phone brand and model do you use?

Apple has admitted there is a problem with GPS data transfer to some 3rd party tracker apps for the model iPhone7.  Distance calculation gets too long and differs every run. Apple has told me they are working on a fix for probably the next iOS update. 

[tbbmomof4]

Samsung Galaxy S6. Any ideas?

[SunsetRunner]

@tbbmomof4 @Rollerskier @Colinm39 I am afraid the topic is going off the tangent here - the issue with GPS tracking is now acknowledged by FitBit and it is a FitBit issue and not a phone issue. The issue is not the tracking but how Fitbit wrongly summarize that.  

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@tbbmomof4 wrote:
Samsung Galaxy S6. Any ideas?

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[Colinm39]

@SunsetRunnerI agree we could be going off an a tangent but we looking/helping to find a solution.. Can you link me to the post that Fitbit have acknowledged there is an issue. ?

[Colinm39]

@SunsetRunnerI have been though all of the pages in this topic and @DerrickS mentions the problem but the relevant software update vaguely addressed that. But as you have all found out the problems with GPS persist. We are all trying to protect our investment hoping it is another side issue.

But no more activity from the Moderators in 5 months and that hasn't helped us, but we will always try to come up with some answers.to guide others.

I posted this in another topic under the Blaze, concentrating on the phones and 4G mobile signal because of my proximity to Telephone towers and suburbia.

Up until now I haven't posted that I replicated the East/West inaccuracy on my Blazes at the same gain as @Glennbest posted. There has been nothing posted in the Blaze forum, but I have two Blazes from Feb and Mar 2016 and they both performed the same way. It was enlightening to see the pace on my Blaze was 2 mins/km faster than the Surge on my other wrist... That prompted me immediately there was an issue because it showed within 20 seconds of my walk.

So I'm hoping the delay in releasing the extra features you have on the Charge HR 2 for the Blaze is addressing the GPS issue.

[tbbmomof4]

Here is a copy of the email from Fitbit support:

Your case has been escalated to the highest level of support here at Fitbit's
headquarter in San Francisco. We would like to continue assisting you with
the inquiry about Charge 2.

First and foremost, we apologize for the delayed response on our end and
your troubleshooting efforts so far.

Note that the Charge 2 does not have a built-in GPS and it relies on the
GPS sensors of your mobile device to track GPS data during your workout.

When you sync your Charge 2 to your account after the activity has ended,
the GPS data that your app/mobile device had picked up will be reconciled
with the data that had originated from your Charge 2 (like the steps,
active minutes, and calories burned) and your stride length. This will not
necessarily match a pre-measured distance, nor will it show exactly what a
GPS device will show. With this being said, it's expected behavior that the
distances you see on the activity log and the actual trail are slightly
different. Additionally,

Unlike other apps or GPS device using a pre-measured distance, Fitbit
trackers calculate the distance by multiplying your walking steps by your
walking stride length and multiplying your running steps by your running
stride length. Therefore, it is expected to see distance discrepancy even
it is the same route because each run would result in different numbers of
steps.

For more information about GPS accuracy please see http://fitbit
.link/1KMcmk0.

Additionally, if you lose signal (e.g.wireless receptionist) for a certain
period of time during your run that you're not aware of, an estimate of
data will be filled in for that period of time that your signal was lost
which you'd see loops on the map. Since the Charge 2 and your phone are
connected based on Bluetooth signal and which could be affected by weak
wireless receptionist, tracker data will always override your GPS data as
your tracker contains more reliable data than the distance provided by your
GPS.

In regard to your step counts on Feb 11th, based on the activity history,
we noticed that the 4.7 miles run gave you 8, 179 steps. Upon reviewing our
back-end tool, the tracker detected 14062 steps based on the last sync in
the evening of Feb 11th.

To further assist you, we would like to know if you noticed any abnormal
activities occurred on the tracker? (like syncing a 3rd party app
concurrently with the tracker, etc.)

[Colinm39]

@tbbmomof4Thanks for the information you received..  Now we have Phones, how distance is calculated and GPS route errors and no constructive comment from Fitbit Moderators.

Like many of the Support emails we receive they conflict with Fitbits own definitions.. Here is the definition of Tracker calculation for distance.copied from the Help area.  I have bolded and italicized the section about GPS...

How does my tracker calculate distance?

Fitbit trackers calculate distance by multiplying your walking steps by your walking stride length and multiplying your running steps by your running stride length. We estimate your stride lengths using your height and gender. If you have a Fitbit Blaze or Fitbit Charge 2 and track one or more runs using connected GPS, we evaluate that data to automatically update your running stride length. For best results, run at a comfortable pace for at least 10 minutes.

If you prefer to measure your walking and running stride lengths yourself and enter them manually, see How do I measure and adjust my stride length?<=== This won't have an embedded link because I have copied the text.

Note that when you're tracking an activity with GPS, Fitbit calculates your distance using GPS data rather than steps. If you begin moving before you get a GPS signal, the tracker will calculate distance using steps and stride length as described above until a GPS signal is found.  

[Rollerskier]

Its not that easy to find out whats causing the different problems with distance but factors are:

1) If you do not bring your phone with GPS.  

The only option for distance is using stride lengths.  One for walking and one for running and considering gender.  Can be manually override as an option.

Obviously not very accurate but gives an indication of distance.

2) If you bring your phone with GPS the factors are:

- Quality of the GPS signals from your phone.  Some phones are better than others on direction stability.  If the error is 5m east on one sampling point and the next point is error 10 m west.  Looks like Fitbit samples every 1 second independent on speed.  You get a wobbling error effect that is stronger for walking than running or using a bike.

- If you loose the bluetooth connection GPS signals are lost and the stride length will fill in the gaphs for this period of time.

- Start up situation..it might take a few second before GPS signals are available.

- Connected GPS to Charge 2 is for some of us different from using the app itself.

- Conversion from longitude and latitude to distance in meters might be a problem in some areas of the Globe.  We have heard that this is a problem in Australia but not been mentioned in the US or Europe?

- there are probably other reasons as well.

[SunsetRunner]

Cheers Mate!

This is exactly the problem I'm having. 

What's the solution if you please?

[majbugman]

@tbbmomof4

Oh God that is funny.  So according to them we have bought a really expensive pedometer.  Thank you for posting.

[Annabel_b]

@majbugman, yep, a really expensive inaccurate pedometer 😞

[Silvercloud]

Wonder if we can get a group price for an Apple Watch? 

[Rich_Laue]

pedometer

[puh-dom-i-ter]

noun

1.

an instrument worn by a walker or runner for recording the number of steps taken, thereby showing approximately the distance traveled.

Origin of pedometer

1723; < French pédomètre, equivalent to péd- (learned use of Latin ped- foot (stem of pēs); see pedi-) + -omètre (see -o-, -meter)

[Silvercloud]

Great so it's not even a pedometer. Did my 2 mile walk today with connected gps. It recorded  1.64 miles with only 2711 steps. So not only does it not somewhat accurately record steps but even with connnected gps-distance. Guess I have an expensive watch.