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Incorrect high speed spikes in garmin connect

I'm using two programs to record gps data on a gps phone while I'm cycle racing - Endomondo and Gacomo. These are both android apps. Endomondo has its own website and correctly shows its own recording without speed spikes. Gacomo is designed to send data to garmin connect .

- Data from gacomo shows high speed spikes
- Data exported from endomondo and imported into garmin connect shows high speed spikes
- That same data within endomondo does not show high speed spikes

I'm seeing the correct time, distance, elevation. The spikes are showing 30mph over what I was probably doing at the time. See here

http://connect.garmin.com/activity/90869068

and this

http://connect.garmin.com/activity/90872287

My true top speed in that race was about 42 mph

Is this a fault with garmin connect ? and does it affect garmin device users ? Anything I can do to fix it ??

thanks
Paul

0 Former Member over 13 years ago

We're the developers of GaCoMo the Android App for Garmin Connect User.

What you see can be split into two parts:

* Download data (TCX file) from Garmin Connect and show this data on the Android device: We parse the TCX file and include this complete data in a local database on the Android device (sounds slow but isn't). Here we can see a lot of spikes. In fact we use a lot of calculations to make for example the map more reasonable. One calculation for example is you can't run or bike 500m in two seconds ;-)

* Record data with the device and transfer this data to Garmin Connect: Here we use the GPS of your device and we take everything that the LocationManager transfers into our app. We don't do any changes to this recorded data at this point. We upload this data unmodified to Garmin Connect and if you download it again the steps mentioned above take place.

I personally don't like to modify user data. So we only make changes where it's really required. We could easily smoothen your map and charts more - but we don't like that. It's the data that has these spikes - it's none of the mentioned software. They simply use different algorithms. For us user data is holy.

Regards
Harald Wilhelm
Admin Service Limited

0 Former Member over 13 years ago

I also saw the spikes when I exported the data via tcx file from Garmin Connect to Garmin Training Center (Training Center gives a more precise graph of the data than Connect does).

0 paull3876 over 13 years ago

We're the developers of GaCoMo the Android App for Garmin Connect User.

What you see can be split into two parts:

* Download data (TCX file) from Garmin Connect and show this data on the Android device: We parse the TCX file and include this complete data in a local database on the Android device (sounds slow but isn't). Here we can see a lot of spikes. In fact we use a lot of calculations to make for example the map more reasonable. One calculation for example is you can't run or bike 500m in two seconds ;-)

* Record data with the device and transfer this data to Garmin Connect: Here we use the GPS of your device and we take everything that the LocationManager transfers into our app. We don't do any changes to this recorded data at this point. We upload this data unmodified to Garmin Connect and if you download it again the steps mentioned above take place.

I personally don't like to modify user data. So we only make changes where it's really required. We could easily smoothen your map and charts more - but we don't like that. It's the data that has these spikes - it's none of the mentioned software. They simply use different algorithms. For us user data is holy.
...

Thanks for replying. Yes if it was a fault with gacomo then the endomondo data wouldn't show the same problem. So its either a fault with garmin connect or inaccuracies in the gps tracking - logically it would be gps inaccuracies, but I was interested in whether garmin devices have the same issue - well my new garmin edge 500 should come in the post today so I'll let you know !

Endomondo does show a very smooth line so obviously their website software is smoothing out the data.

I was not transferring data from garmin connect to the device, I was simply uploading to garmin connect from gacomo.

Glad you don't mess with the data - raw gps is the best and let the web servers do that kind of data smoothing etc. Thats absolutely the right approach.. thanks