Ionic GPS inaccurate

[ljansen]

I have an Ionic. I have noticed that when I use it for running and also use my mapmyrun app, the Ionic distance is shorter than the mapmyrun distance. I have checked it with google maps and the mapmyrun distance is correct. Why is my Ionic distance not correct?

[LanuzaFitbit]

Welcome to the Forums @ljansen.

I will be moving this thread to the Ionic board as it is the better place for your question.

As for why the discrepancy, it is possible that the GPS connection with the Ionic was lost at some point during the run and thus that caused the distance information to be off as it was not tracking it at all times. Were there many trees, buildings, or clouds on that day? If so, that could cause the connection to be interrupted.

Let me know if you have any further questions.

[ljansen]

I have checked the results numerous times. It is always short on miles compared to mapmyrun and google. The areas I run are out in the open with very little interferences. 

[LanuzaFitbit]

Hello @ljansen.

Thanks for checking on that. 

I'd recommend going through this article to better understand what could be happening. It should definitely help understand what could be happening.

Let me know if you have any further questions.

[BS3Rob]

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@ljansen wrote:

I have checked the results numerous times. It is always short on miles compared to mapmyrun and google. The areas I run are out in the open with very little interferences. 

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Search this forum, this is a known issue that has been mentioned many times. The reason is that for whatever reason the Ionic does not use GPS tracked route as a measure of your distance, it uses your average stride length extrapolated by number of steps.

I'm not sure why Fitbit don't just mention this in their response, very strange. Incidentally currently I am also running with MapMyRun also tracking on my iPhone and see the same as you, Ionic consistently shorter, MMR often holds the GPS track better too.

[BS3Rob]

As if to prove my point, just ran my daily 10km route which I've done for two years and know exactly by distance door to door - if GPS signal is good it hits 10km on MapMyRun or Strava as I'm getting home.

MapMyRun on iPhone hit 10km yards from my front door just now. Ionic was only showing 9.53km. I ran a length of a neighbouring street to get it up to 10km, by which time MapMyRun was saying 10.54km!

Now the iPhone is by no means infallible - I had GPS issues with it too, which is why I bought the FitBit (doh!), so patchy GPS on some days is not a surprise, but the Ionic is consistently 5% out on distance.

As I said on other threads, I bought an Ionic so I could be less distracted when running and to enhance my fitness work. I'm sure that's the Fitbit sales pitch, sadly this inaccuracy (and bugs) do the opposite.

[bmw54]

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@BS3Rob wrote:

This is a known issue that has been mentioned many times. The reason is that for whatever reason the Ionic does not use GPS tracked route as a measure of your distance, it uses your average stride length extrapolated by number of steps.

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This subject has been discussed at length starting October 2017, when the Ionic first started shipping. (find the GPS Inaccuracies thread) Fitbit won't explicitly reveal what their logic is, but it appears that the Ionic uses GPS to plot your map routes and, occasionally, to measure stride length.

It uses stride length to measure pace and distance.

When I first started racing with my Ionic I found it measured pace and distance ridiculously inaccurate. 5K races consistently came in at 2.5 miles and pace was crazy-overstated. That prompted months of research, chat sessions and frustration.

If you want to make the best of a bad thing (keep your Ionic, that is) I recommend you make sure you've set stride length to to 'set automatically'. Find it in your personal settings. And then keep using it; it seems to get more accurate after months of use. 

In my experience there's only one thing I can count on with the Ionic: the more critical the need, the higher its chance of failure.

[MattFitbit]

@bmw54 @BS3Rob Just thought I would jump in here to provide a little clarification on this matter. 

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. Once the GPS signal is found, Fitbit uses both GPS and step rate and stride length to compute distance for lower error.

Hopefully, this helps to clear things up. If you have any additional questions, you know where to find me. 

[BS3Rob]

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@MattFitbit wrote:

@bmw54 @BS3Rob Just thought I would jump in here to provide a little clarification on this matter. 

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. Once the GPS signal is found, Fitbit uses both GPS and step rate and stride length to compute distance for lower error.

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Hi @MattFitbit

I waited until I had GPS (over 3 minutes today in freezing temperatures as it happens!) so I definitely didn't start running without GPS, and today at least I didn't see or get an alert to it reconnecting to GPS, even if the track on the map was off in several places, so I don't think the case you describe applies.

If you're certain that it IS using GPS, then the issue is simply that the GPS track is way out (which is what I see on the map for every run with an Ionic that hasn't crashed!) resulting in the calculated distance being off. That would make sense to me, although others have insisted that the issue is using steps?

More odd today, I see this on the Fitbit (web based) dashboard. It actually has two entries, one with the exact and correct distance. I have never seen the Ionic do this before. If I click on it, it has no map. But this proves the Ionic does somewhere know the real distance (10.53km) but is not using it properly.

Could you please have an engineer comment on this. Since many people have been frustrated by the GPS and distance accuracy, suddenly seeing an erroneous duplicate entry, but with the exact correct distance, raises all sorts of questions about what data the Ionic has and what the software is using it for.

[bmw54]

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@bmw54 wrote:

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Last week I stated:

In my experience there's only one thing I can count on with the Ionic: the more critical the need, the higher its chance of failure.

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That continues to be true. Here's the map for my most recent marathon (Ocean State, October 28 - coastal setting, no forests, no buildings, decent weather):

Ionic's mapping of Ocean State Marathon

Hey, this time it made it close to mile 9 before losing GPS connection. It only made it to mile 5 last April in the Boston Marathon. The kid I paced with yesterday had some inexpensive model of Polar. It worked fine.

[BS3Rob]

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@BS3Rob wrote:

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More odd today, I see this on the Fitbit (web based) dashboard. It actually has two entries, one with the exact and correct distance. I have never seen the Ionic do this before. If I click on it, it has no map. But this proves the Ionic does somewhere know the real distance (10.53km) but is not using it properly.

Could you please have an engineer comment on this. Since many people have been frustrated by the GPS and distance accuracy, suddenly seeing an erroneous duplicate entry, but with the exact correct distance, raises all sorts of questions about what data the Ionic has and what the software is using it for.

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Hi @MattFitbit,

Could you please comment on this. It seems extraordinary to me that this isn't worthy of some kind of comment, given the many threads on this forum about inaccurate and step-based GPS distances, yet the exact distance of a run being (accidentally) visible here, erroneously, in the FitBit companion app. What has this revealed and will the engineers work on making better use of this data which exists?

As an aside, I have got nowhere with my Ionic (just 2 weeks old), I have posted in other threads about my experiences - I haven't had 1 fully functioning run yet after 7 x 10km. I now follow all the workarounds (reboot, fully charged, don't use music, tap read out during first 1km). It hasn't crashed (i.e. terminated a run) for a week now but the GPS still appears under-powered and prone to total failure during a run.

This morning my 8th 10km since purchasing the watch, I decided to use music again (with all the other workarounds) to see if I could actually eliminate music as an issue. It started off perfectly, tracking the same pace and distance of my iPhone and my 2 year experience of a route. I was so excited that it was finally working. Then after 5km the GPS reverted to connecting, and struggled for the rest of the run.

In the end it was in and out of GPS for the rest of the run - and when I reviewed the route, it was actually struggling with GPS from about 3km: navy line below is iPhone, orange line is Ionic. By the last 5km it is flying over roads and making it up as it goes along. Still the distance and time in the end wasn't too bad for accuracy (for the first time ever), which is the thing with Ionic - always one thing that gives you hope.

Nonetheless at this point this is going to have to go back to Amazon under their returns policy as I don't know what else I can do to be patient. The quality of feedback/solution from Fitbit has been really poor (my first ever experience of Fitbit as a company) and support involves taking you off the forum to email, but having no practical answers, and then suggesting that Fitbit replace the item directly themselves.

I have the distinct impression these are simply all known issues with no resolution - possibly because the hardware is flawed or underpowered - and Fitbit would prefer to minimise retailer returns (which creates poor feedback) and instead get users into a cycle of long manufacturer return processes, which keep you trapped a Fitbit customer, and close off your rights to a refund via your retailer (in the UK at least).

If that's not the case then I apologise, but as a show of faith from Fitbit, some actual feedback about the mysterious entry above with the correct GPS distance alongside the incorrect distance, would be a start.