Ionic GPS Inaccuracies

[MP4]

Hi, 

I'm a new Fitbit user, bought an Ionic on Monday and I'm having some issues with the GPS. Went on a couple of runs (at a track) and the gps seemed to be completely out both on the distance travelled and pace per kilometre.

I'm a long time strava user so yesterday I went for a run with both the Fitbit Ionic going and the strava on my iPhone running at the same time. Here are the results:

Strava - 7.9km   @ 4:15/km

Fitbit - 7.2km     @ 4:34/km

The difference of 0.7km is quite big and the difference in pace is also worrying. I waited till both had connected to gps before starting the run and I run in London where gps signal should be good. 

Is my Fitbit Ionic GPS not working correctly? Any help/advice would be appreciated. 

Thanks

Matt

Moderator Edit: Updated Subject for Clarity

[MattyW]

That is mysterious. And it says you have "set automatically" unchecked in
that setting?

[the_one]

Update:  Fitbit support has reached out to me privately and are looking into the technical issues that could be causing the inaccuracy. Must give kudos to the team Fitbit for the quick response and initiating the resolution. I shall keep you all posted once the fix is in place.

[bbarrera]

Well, this is interesting:

"Fitbit devices calculate distance by multiplying your walking steps by your walking stride length and multiplying your running steps by your running stride length. By default, we calculate your stride length using your height and gender. If you have Fitbit Blaze, Fitbit Charge 2, Fitbit Ionic, or Fitbit Versa and track one or more runs using 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."

Source: http://help.fitbit.com/articles/en_US/Help_article/1135/

@Giampi71 if it was me, I take my 42" / 107cm stride and bump it up by 15% (48" / 123 cm). A stride that is reasonable but obviously longer or shorter. Disable automatic stride update (is that possible?). Sync to Ionic and go for a short run of 15-20 minutes. Then I would review distance to determine if Fitbit used my manually set stride, or if it used auto-calculated stride. 

It might be that Fitbit will always use auto-calculated stride on GPS runs. If true, then perhaps the issue for some is that step detection is wrong from time-to-time, which will lead to under- an over- reporting of distance. Just a wild guess.

[bmw54]

Add to @bbarrera's statement regarding distance calculation this (partial) transcript from my 'chat' with Leon, a Fitbit rep, last December when I'd competed in yet another race where Ionic's pace/distance calculations were ridiculously incorrect:

Me (12/21/2017, 9:16:57 AM): my problem has been that the watch is fairly accurate day-to-day. but useless when I race - that's when I value it the most. Leon (12/21/2017, 9:17:36 AM): I totally get your point on these, and I see the utility that this has for your performance. Leon (12/21/2017, 9:18:09 AM): Of course, that's the reason why our engineer team is looking to it, so they can release a fix for this as soon as possible. Me (12/21/2017, 9:19:50 AM): ok... one test I did a couple weeks ago was to fire up the running app and then cycle 6 miles. because the step count was so low, ionic 'measured' .4 miles and something like 100 minutes per mile. (almost perfectly equal to stepcount * running stride length) Leon (12/21/2017, 9:20:42 AM): Thanks a lot for bringing this details of the results of this test. Me (12/21/2017, 9:21:48 AM): is there any way to correspond with an engineer? in another month i'll start training for Boston Marathon. I have to have the problem corrected by then or I'm better off leaving ionic in my bedroom Leon (12/21/2017, 9:23:47 AM): Thanks for letting me know this. We apologize for all the inconveniences it has caused you. Leon (12/21/2017, 9:24:48 AM): Our engineer team may check your case to have a better perspective of this situation. However the fix for this, may be done internally. However we recommend to always have the latest Fitbit app and firmware update installed on your device. Me (12/21/2017, 9:25:21 AM): yes I've always installed firmware updates asap Me (12/21/2017, 9:26:46 AM): but to be clear, I'm not missing any setting that forces distance and pace to be measured by stepcount, right? Leon (12/21/2017, 9:27:38 AM): As per the overall settings for the Ionic, everything seems to be correct. However, you could try adjusting the stride length manually to see if this can also be of help for you. Leon (12/21/2017, 9:27:46 AM): May I know if you have tried changing this manually? Me (12/21/2017, 9:28:22 AM): no... I didn't know I could until I started having these innacuracies on race day Leon (12/21/2017, 9:28:44 AM): Thanks for bringing this to our attention. Leon (12/21/2017, 9:29:00 AM): In that case I can send you an email with instructions to adjust this manually, is that okay? Leon (12/21/2017, 9:29:23 AM): Great, please bear with me for a moment while I draft it for you. Me (12/21/2017, 9:29:54 AM): but what I really want is for ionic to use GPS. It's very accurate... It even indicates where I've crossed roads. Leon (12/21/2017, 9:31:39 AM): Thanks a lot for letting me know the GPS it's very accurate. For this reason the stride length should be adjusted as well to ensure everything is in optimal adjustments and prevent this kind of discrepancies. Me (12/21/2017, 9:32:48 AM): but remember... my stride length changes when I race. that's the objective and I don't want to have to guess what my stride length will be. Leon (12/21/2017, 9:34:00 AM): That's correct, for that reason on the email I sent it is explained how to calculate running stride length. Me (12/21/2017, 9:34:43 AM): I know i'm holding you up here... but doesn't the cycling app use GPS to calculate distance and pace? Leon (12/21/2017, 9:36:01 AM): The cycling activity on the exercise app, uses GPS but not for pace, instead it calculates stats like: speed, speed (average), lap, lap time, time of day, calories burned, distance,heart rate. Me (12/21/2017, 9:36:29 AM): speed and pace... somewhat similar. Leon (12/21/2017, 9:36:57 AM): That's correct. Me (12/21/2017, 9:37:00 AM): does fitbit realize that running stride varies significantly between training and racing? Leon (12/21/2017, 9:38:23 AM): Yes, for that reason, there is the automatic stride length setting, which will calculate this based on the GPS data on the Ionic. Me (12/21/2017, 9:39:53 AM): ok... I hope it becomes more dynamic and is used every time i run. and often within a run. Leon (12/21/2017, 9:40:25 AM): Yes, actually this is done every 10 minutes as it evaluate that data to automatically update your running stride length. Me (12/21/2017, 9:41:20 AM): nice. what should I do if mine doesn't start performing this update? Leon (12/21/2017, 9:42:38 AM): Now that we've restarted it, this shouldn't happen. However, if after taking this suggestions into account you still haven't noticed anything, you can reach us back to see if we can further check this, while our engineers are working on this. Me (12/21/2017, 9:42:48 AM): ok thanks

I suspected it soon after receiving my Ionic in October, but since December I've known for sure that the Ionic is not using GPS for pace and distance. The periodic re-calculation - if done as Leon described to me - should assure fairly correct training run stats. But the fact that it never gets my pace correct in racing leads me to suspect they have some error-detection logic that defaults into different logic when it senses your pace is minutes different from 'normal'.

Moderator Edit: Format

[Denodan]

Trouble is your stride is never constant even manually adjusting it. As you get tried is when your stride will be differeint. We are not machines that could have a perfect stride.

Going up hill or down can alter stride also and if you where your running is not totally flat will alter your step.

There is no way to get a watch that perfect.

[bbarrera]

Fitbit has an interesting "all in" commitment to steps. While I somewhat understand the Fitbit perspective, seems like an odd approach to estimating distance on walks/hikes/runs. 

Its not just stride that changes, sometimes the tracker picks up false steps, or misses a few steps.

[groberge]

I received the OS 2.0 update today.  Seems they've added a few different ways to get things such as daily status, music and coach on the buttons.  It would be nice if the buttons were programmable.  I'd much rather be able to get to my Run exercise faster than getting to the Coach or Music.

I also see that Deezer (music streaming app) is now on my Ionic.  I tried activating it as instructed but it didn't seem to do anything.  I store my own music so I don't know how much I'd use it anyway but I'll at least give it a shot.

I'll be taking the Ionic for a run tomorrow and I'll compare it to MapMyRun.  I did put it on the Run exercise to see how long it would take for the GPS to connect and it took between 40-45 seconds...much longer than I had hoped.  I could live with this if the GPS is accurate and stable once started.

I'll update tomorrow with my results.

[Giampi71]

---

@MattyWwrote:
That is mysterious. And it says you have "set automatically" unchecked in
that setting?

---

You know what? I was sure that I unchecked the automatic calculation but when I checked again the setting it was checked (and I found out that it automatically set my stride at 100.5 cm). So I'm going to try again another test with manual pace at 115 cm (as suggested by @bbarrera) and I will report my test, probably tomorrow.

But I have the feeling that indeed it's a steps calculation, still working very well for me

[imeson79]

Strangely enough, today i did a walk with my Fenix 5x and the Ionic, they usually are out on the ionic by about 100 meters or more. 

After i had the OS 2 update  it was only out by 10 meters. Not saying that its definitely solved, but something has changed since the last update. Here's hoping it stays true. 

[BahGahWah]

I notice the exercise app version has changed with the OS 2 update. I don’t think this version changed in the February update.  Hopefully there will be some improvement in the run tracking performance.

[groberge]

I ran today for the first time with OS 2.0 and my results aren't any better than before the update...in fact they may be worse.

After the last update I had 4.97 vs. 5.00 and 5.95 vs 6.00 when looking at Ionic vs. MapMyRun and uploading the .tcx file.

Ran today with the following results:

Fitbit shows 4.35 miles. tcx file shows 4.41 miles

MapMyRun shows 4.46 miles and .tcx shows 4.46 miles.

Looking at the two maps, it looks like the Fitbit has me stopped a little before MapMyRun.  I walked a little further before getting my phone to stop but I didn't think it was .05 miles.

Still looks like the Ionic is using steps to calculate distance rather than just plain reading the .tcx file that is created.

While .11 miles doesn't seem like a huge amount, it's enough to change my pace from 9:14/mile to 9:28/mile.

I'll be trying it out again tomorrow but I'm not very hopeful.

[Tex52]

@SilviaFitbit I didn't see any mention of GPS improvements listed under the OS 2.0? Does this mean we are still stuck carrying a 300 dollar step counter that is useless for training? I need to know if anyone is working on the GPS problem because I have a limited time to return this device for my money back. I don't plan to keep this device if they are not going to fix the GPS issue.

[Tunah85]

Updated to Fitbit Ionic OS 2.0... and I continue to experience the same GPS issues.

Most recent run was 6.5km (6.51km on Strava... 6.52 on Map my Run)

Ionic logged it as 6.41 - I was already missing 100m on this short run!

Km#         Strava Split (4:46 average)   Ionic Split (4:51 average)

1                      5:05                                     5:12

2                      4:52                                     4:57

3                      4:55                                     5:01

4                      4:45                                     4:49

5                      4:36                                     4:37

6                      4:38                                     4:39

6.5                   4:22                                     4:29

Once again, when I upload the Fitbit TCX file to Runkeeper, it corrects the pace and distance to within a 1s/km average of Strava's data... As expected the distance is corrected as well (6.5km).

Same GPS issues continue to plague this update... I have a 30km race coming up this weekend, so we'll see what the Ionic says at the end of that!  At its current pace it could be out by 500m!

[Tex52]

@Tunah85

Under the OS 2.0 changes page there is no mention about GPS improvements. Just appearance changes to make it a cooler looking 300 dollar step counter.

[Denodan]

They all vary so you cannot know what app is the more accurate? 

[imeson79]

I think they should check out other GPS units, like Garmin or Suunto, or Polar, and see how they register GPS accuracy. 

Mind you mine came into alignment after i changed my stride from 75cm into 35 and then clicked on Automatically adjust.

Don't know if that will help or not

[Denodan]

Wont help they would all read slighly different, even apps very slightly.

[imeson79]

Wonder if it would make a difference if we could call on the GPS functionality if we decided to use Fitbit SDK to develop a running app? To see if it's a hardware or possibly software issue? It should be possible if they allow for us to call on the gpz

[bbarrera]

I believe Fitbit help documentation, bmw54's chat transcript, and various posts in this forum make it clear that steps are used to calculate distance. We can end that debate. Steps are used to calculate distance on runs/hikes/walks.

That means distance errors can be introduced from any step counting errors, and any stride estimation / GPS errors.

The advantage of only using GPS for distance is that the GPS track can be filtered to remove any obvious tracking errors (and steps are not part of the distance calculation). 

I believe there is a GPS tracking app you could try now, however keep in mind that unlike your phone, there is no general multitasking on Ionic. More importantly the Fitbit SDK/webAPI doesn't allow GPS or HR to be imported into your activity dashboard. Therefore any runs tracked using a 3rd party app will result in (best case) a manually tracked activity without GPS map.

[BahGahWah]

@bbarrera agree that the ionic behaviour leads us to believe that the GPS is not being used to provide distance and pace stats while running.

@Fitbitblog Infers that this is not as intended, as my reading of this is that the leading GPS performance is being used to provide pace, distance, etc.    At the moment we only appear to be seeing the map function being implemented by GPS.

https://blog.fitbit.com/fitbit-ionic-release/

“You Need: Route Tracking
Fitbit Ionic Has: An integrated antenna that provides a stronger connection to GPS and GLONASS satellites, delivering leading GPS performance. That means you can leave your phone behind and still get accurate heart rate, pace, distance, elevation, and split times right on your wrist, as well as a map of your walk, run, or ride in the Fitbit app.”