Suunto 9 Highly inaccurate speed readings

surfboomerang · 13 Jan 2019, 16:29

I exported the FIT files from sports-tracker and uploaded them to the Quantified self site.
Here are parts of the same activities as my previous post:

Suunto 9

Ambit 3 peak

So for running (suunto 9 capture 2 and Ambit 3 capture) it looks quite ok now. For windsurfing however (suunto 9 capture 1) the spikes are still there.

Another thing I noticed when I analyzed the files on the Quantified Self page was my heart rate graph from Suunto 9 and Ambit 3 peak. In both activities I used the same HR belt but look at the graphs below…

Ambit 3 peak

Suunto 9

Dimitrios Kanellopoulos · 14 Jan 2019, 09:39

the HR is not filteredd in that tool. The more spikes the worse the belt is.

About windsurfing I am not sure I have never tested that high speed sport.

surfboomerang · 14 Jan 2019, 15:30

The Ambit activity was synced from Movescount to sports-tracker. The Suunto 9 moves were synced with the Suunto App…Is it possible that the data of the Ambit 3 was already filtered by Movescount?

I will do another run today and treat the HR belt connectors with gel to see if that will improve the readings.

Dimitrios Kanellopoulos · 14 Jan 2019, 15:36

@surfboomerang yes it can be.

I would just not trust any GPX exports from ST.

And in general GPX

surfboomerang · 14 Jan 2019, 15:44

I know, but how am I suppose to export a fit file from Suunto app at this moment?

Dimitrios Kanellopoulos · 14 Jan 2019, 15:45

@surfboomerang good one.

there was somewhere one hacky thing posted. I need to dig that up.

If you have strava sync you can via web-> Go to the activity and append in the url /export_original that will give you the .fit file that was send to strava

surfboomerang · 14 Jan 2019, 15:48

Thanks, I will try that this evening.

surfboomerang · 14 Jan 2019, 19:14

@Dimitrios-Kanellopoulos I exported the same activities as before, but this time from Strava with the method you mentioned. Worked like a charm!
After that I analyzed it in the Quantified Self site, but unfortunately the graphs for windsurfing are identical to the one I exported from Sports-tracker. So the spikes and drops are still there.

I also did a new run today with the heart rate belt and some contact gel, but I still see the spikes in the heart rate graph. The Suunto App shows the HR graph ok (so it filters out the spikes)

Brad_Olwin · 14 Jan 2019, 19:34

@surfboomerang said in Suunto 9 Highly inaccurate speed readings:

@Dimitrios-Kanellopoulos I exported the same activities as before, but this time from Strava with the method you mentioned. Worked like a charm!
After that I analyzed it in the Quantified Self site, but unfortunately the graphs for windsurfing are identical to the one I exported from Sports-tracker. So the spikes and drops are still there.

I also did a new run today with the heart rate belt and some contact gel, but I still see the spikes in the heart rate graph. The Suunto App shows the HR graph ok (so it filters out the spikes)

For HR, it is likely your belt is bad, not the sensor. When I routinely see HR spikes and I have cleaned the belt, it is time for a new one. Also, spikes can be worse in the winter if you wear fabrics that transmit a lot of static electricity.

Dimitrios Kanellopoulos · 14 Jan 2019, 20:14

@surfboomerang I need to add filtering at that tool then

Dimitrios Kanellopoulos · 14 Jan 2019, 20:17

@surfboomerang btw joke as these spikes are natural to happen with others as well.

Now back to the windsurf issue. Could you for just my sake use a swim profile or standuppaddling? Some water profile that is designed for on water GPS. I suspect that is the issue. SUP will do I think to make the gps more relaxed on reflections.

S9 uses different GPS profiles for each type of movement. FYI

surfboomerang · 14 Jan 2019, 20:38

Always worth a try.

Although I doubt that it will work because I’ve seen this same behaviour in a car on cruise control. See https://forum.suunto.com/post/16076. I used sports profile “Other” there. (or at least I think it is translated to “Other”)

I will try with the SUP profile for windsurfing next time. Hoping for some good wind in the near future. And of course some free time

GingerBeardMan · 15 Jan 2019, 08:00

I find, when running, if I do fartleks, intervals or other workouts that include quick changes of pace my suunto 9 will log me as having achieve super human speeds at the beginning of the interval before settling down to something more realistic.

surfboomerang · 20 Jan 2019, 20:12

@Dimitrios-Kanellopoulos Because the wind forecast is not very good in the near future, I decided to test the profiles by car to see if the SUP or WIndsurf profile does make a change.

I started an activity with a SUP profile and drove on the highway with the car on cruise control (about 110 km/h). Below is the resulting graph:

I also did the test with the Windsurfing profile (cruise control at 100 km/h):

The windsurf profile looks pretty clear this time, but I doubt that this is because of the profile I think I was lucky with such a clean graph this time. As you can see on my first graph it can still spike really up and down.

What really grind my gears is that the spikes are almost always identical in height and in a lot of the cases has the same drop value as the spike a second before.

An example to clarify:
If I drive an average of 110km/h and I see a spike of 120km/h, in a lot of cases it follows the next second with a drop to 100km/h. So it averages again to 110km/h, but the recorded max speed is 120km/h

It is so common that the spikes are almost identical in height and drops that I can’t really imagine that this is a GPS reception issue. More like a GPS recording issue. Like the watch is recording too fast ahead and than slowing down to compensate…

If you look at the line below, I see that the trackpoints are perfectly in line with the driving direction, but they do not have even distance between them some are closer of further apart, although I was driving at a constant speed.

Is there a possibility to see the number of satellites or reception quality from the recordings?

Dimitrios Kanellopoulos · 21 Jan 2019, 11:08

@surfboomerang keep in mind that the spikes are vise versa. Aka you stopped.

Dimitrios Kanellopoulos · 3 Feb 2019, 17:49

@surfboomerang I am working on QS v2 to show those differently and support more data btw

surfboomerang · 25 Jan 2019, 08:33

Little status update:
Suunto support requested to return the watch for investigation.

Lets see if they can find something…

surfboomerang · 2 Apr 2019, 06:16

Watch is replaced by Suunto support. Just got my new one.
My first run looks promising. No real spikes like I had before. I’ll test high speed sports soon to see if my issue is really resolved.

surfboomerang · 3 Feb 2019, 17:49

@Dimitrios-Kanellopoulos The new version of the app looks great btw!!

Is it possible that the suunto 9 doesn’t record all the fields you have in the app? (like battery level, GPS satellite status etc…).
Because I selected those settings in my profile settings, but the data was not available in the graph.

Dimitrios Kanellopoulos · 4 Feb 2019, 09:17

@surfboomerang those fields are recroding just not exported. You need the SML files and I still dont have support for those. However I will add as it’s at least the last feature I ll push for now.

Regarding my data that have those fields that is because we use another tool internal to extract those data