Ionic GPS data different than Strava

[Mouncey189]

I have noticed a few times now while logging walks or a run that the Gps data for distance and pace can vary. An example of this is yesterday i logged a run in the exercise app on the ionic with gps on and the fitbit app has recorded it as a 3.64 miles and avg pace as 11.18 mpm Strava has it at 3.99 miles and avg pace of 10.33 mpm. Any ideas which is more accurate or how to improve accuracy ?

Moderator edit: Updated subject for clarity 

[SilviaFitbit]

@Mouncey189 Welcome to the Community. Thanks for the details shared about the miles were recorded on Ionic and Strava. 

All devices with GPS sensors require a direct path to GPS satellites to calculate location. A weak GPS signal might affect the accuracy of your route and other activity data. Your device uses your step count to calculate distance until it finds a signal, so the total distance calculated for a workout may be slightly less accurate when GPS isn't available for the entire time. 

Please make sure your Ionic is charged to at least 80% when using GPS and confirm that you have a clear view of the sky when you start the exercise. Environmental factors, including tall buildings, dense forest, steep hills, and even thick cloud cover, can interfere with your device’s ability to connect to GPS satellites. If the signal is blocked—either because you're indoors, underground, or due to another reason—GPS won't work. 

I'll be around if you have any additional questions. 

[Mouncey189]

Thanks for the reply ! I just found it strange that they varied when both apps had used the same device to record the activity !

[Iain_K]

@Mouncey189 

I call BS on the GPS signal explanation.  Yes, the GPS can lose its signal, which will result in some weird traces, but as far as any differences between Strava and Fitibt goes for the same run, they are both using the same raw data from the Ionic, so that cant account for the discrepancies we see.

Did you use the pause button at all?  Ive seen that using pause at points in the run will really mess up how Fitbit and Strava apps process the same raw GPS data from the Ionic.  That probably goes for stopping to cross a road or whatever too when it might autopause depending on your settings.  

Take the attached example. Both March 20 12.12pm, but Fitbit did not take "paused" time into consideration with the pace and shows as 3 minutes longer.  However, the map stopped tracking after the final lap.  Strava on the other hand, despite using the exact same data obtained by linking with my Fitbit account, gets the pace correct (So it does not include the paused time between repetitions), but for some reason it does shows the walk back inside before I hit "end" on the exercise session while the watch was only paused.  Not even sure this is a "moving time" vs "total elapsed time" thing, its just weird.

Go figure.  Bottom line is I trust the stats from the Strava processing more than the Fitbit analysis.  And not just because Strava says I'm faster:)

Bare in mind here the Ionic is the only thing recording the GPS data, so all the differences are entirely in how the apps use that same data.

[Mouncey189]

Thats is what i thought as like you said they both used the same Gps data. As it happens i did pause that activity at the halfway point while i caught my breath ! Maybe that is the cause although i have had variations with walks i have done aswell where i havent paused the activity. I think in the future ill just go off the figures strava give me ! Thanks for the reply btw