Race 2: GPS, cadence and distance accuracy vs previous Suunto models
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@wakarimasen Please, no “violence” here
The origin of the thread was “Have you noticed if the new hardware measures less distance in activities than the previous watches?”.
Just a question, just a comparison between behaviors of different watches with “similar” hardware and software.
The topic wasn’t (at least primarily) about discussing (or complaining about) GPS technology or professional map creation, although any information is welcomed to learn about it (Telecommunications Engineer here, I know some things about GPS technology
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@wakarimasen said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
An interesting read for all of those suffering GPS distance errors which equate to 1-2% of the total distance travelled.
GPS mileage discrepancies
That post is from 2016 when single band GPS was the only option and the accuracy was rather mediocre. Around 2022 there was a real breakthrough in GNSS accuracy, and now even cheap watches easily achieve 1 meter accuracy for a single position when using multi-system multi-band GNSS. A consistent bias of 0.5-1% in the distance measurement is no longer a random thing caused by GPS but a systemic error caused by the algorithm.
Furthermore, as has been explained above, the actual GPS distance remains accurate. The bias is introduced in post-processing, likely when fusing accelerometer and gyroscope data with the GPS data. I bet there is no such bias when doing a cycling activity and it applies only to walking or running. I know that Garmin does a similar thing for walking and running. They want to continue measuring the distance when GPS reception is lost, for example when briefly going through a tunnel or under an overpass, or near tall buildings. So the sensor fusion is continuously performed and that may make the measured distance different from the GPS distance.
Suunto: Ambit, Ambit 3 Peak, 9 Baro, Race S, Race Ti
Garmin: Forerunner 210, Forerunner 610, Fenix 6X, Fenix 7X Ti -
@jjpaz said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
@wakarimasen Please, no “violence” here
The origin of the thread was “Have you noticed if the new hardware measures less distance in activities than the previous watches?”.
Just a question, just a comparison between behaviors of different watches with “similar” hardware and software.
The topic wasn’t (at least primarily) about discussing (or complaining about) GPS technology or professional map creation, although any information is welcomed to learn about it (Telecommunications Engineer here, I know some things about GPS technology ).I bow to your greater GPS knowledge! As I mentioned, I’m wondering if Suunto have down something on the post processing side, to change the output from previous watches. The other point however, is that it’s not beyond the realms of possibility that this new data may actually be more correct than the previous one. This is the problem with comparing devices and not having an accurate reference.
No violence from my side - just curiosity, with a hefty slice of realism
Suunto Race Titanium
Suunto Ambit3 Peak
Polar H10
Polar OH1 -
@sky-runner said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
@wakarimasen said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
An interesting read for all of those suffering GPS distance errors which equate to 1-2% of the total distance travelled.
GPS mileage discrepancies
That post is from 2016 when single band GPS was the only option and the accuracy was rather mediocre. Around 2022 there was a real breakthrough in GNSS accuracy, and now even cheap watches easily achieve 1 meter accuracy for a single position when using multi-system multi-band GNSS. A consistent bias of 0.5-1% in the distance measurement is no longer a random thing caused by GPS but a systemic error caused by the algorithm.
I know that Garmin does a similar thing for walking and running. They want to continue measuring the distance when GPS reception is lost, for example when briefly going through a tunnel or under an overpass, or near tall buildings. So the sensor fusion is continuously performed and that may make the measured distance different from the GPS distance.
Yes indeed, this is referenced in the (old) article. Given the over estimation that has been prevalent in devices, I’m merely wondering if this is the reason that distances have been reduced - perhaps with the introduction of a new ‘correction’ factor.
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@sky-runner said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
bet there is no such bias when doing a cycling activity and it applies only to walking or running.
I think I reported very early in this thread that I didn’t notice any changes to the distance between S9B and Race 2 when biking (potentially<50 m on a 50 km ride, and this always varies from session to session).
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@wakarimasen said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
I think we may be ‘agreeing violently.’
Agreed!
Nevertheless, I would be very surprised to learn that ‘official’ mapping is carried out by someone wearing a Suunto, Garmin, Polar or Corus device, and declaring the data ‘accurate.’
Only for OpenStreetMap
I made an interesting observation a few years ago when testing the SV1’s different GNSS presets (Performance vs. Endurance vs. Ultra). It seems that, as the GNSS accuracy/signal/capabilities (whatever you want to call it) increases, the measured distance decreases. Makes sense as fewer errors mean straighter lines and less distance. So it could stand to reason that the newer watches have even more accuracy, therefore measure slightly less distance.
However, I think this goes against all the work and analysis that @jjpaz has provided us here. It clearly looks like new watches have a different algo. My money would be on it having something to do with battery savings for those big, bright screens.
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@duffman19 as a single data point, I have compared my multiple (two different Garmins, three different Coros, and three different Suuntos, one of them the Race 2) to my measuring wheel. All of them compare favourably except the Race 2, which measures short every time, in the error range we’ve talked about in this thread (usually closer to 0.5% and not as often up to 1.5%). My wheel is accurate (and technique with it is good), so from my perspective it is indeed that the Race 2 measures short, even with straight and flat lines. A great watch in many ways, one that seems to be a bit off where (imho) it matters most.
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@wakarimasen said in Race 2: GPS, cadence and distance accuracy vs previous Suunto models:
I bow to your greater GPS knowledge!
Uhmm, irony?
As I mentioned, I’m wondering if Suunto have down something on the post processing side, to change the output from previous watches. The other point however, is that it’s not beyond the realms of possibility that this new data may actually be more correct than the previous one. This is the problem with comparing devices and not having an accurate reference.
No violence from my side - just curiosity, with a hefty slice of realism
I completely agree. I’m very realistic about the GPS capabilities of a device worn on the wrist. and I haven’t cuestioned the ‘absolute’ accuracy of the devices.
When I run ~10K I really don’t know if I’ve run 10,2km or 9,8km but I can compare numbers in different devices as a reference.And that’s the point (and the title) of the topic: “relative accuracy vs previous Suunto models” because it seems that this concrete model has a “different calibration” that shows different measures (relatively to the other models of the same brand with similar recorded GPS data).
This is the origin of my curiosity, because comparison is not against Garmin, or Coros, or Polar, is against “brand brothers” which show different output information with similar recorded input information and I suposse that Suunto has his own references and tests to measure “accuracy”
That said, I still use the Race 2 daily, I still use it in my activities, I’ve adjusted my “expectations” regarding pace (around 3-4 seconds per kilometer) and I enjoy it, and that’s it.
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Hi everyone, unfortunately, I’ll be returning the Race 2 due to this GPS issue. I continued to run more tests, even pairing it with a Garmin Edge 530 (in bycicle mode), and the result was the same…a loss of about 130-150 meters over 20 km.
At this point, however, I don’t want to make any more mistakes and am considering getting the Race 1, but I understand that the user @jjpaz comparisons don’t mention the Race 1, but rather the Race S and the Vertical.
Do you think it might have the same problem, or should I be okay with it?
I’d also be leaning toward the Vertical 2, but I’m worried it might have exactly the same behavior as the Race 2 in terms of distance loss.
Do you think the Race 1 is significantly behind the Race 2 in terms of technology?
I love the Suunto style and would like to stick with the brand.
Thanks to anyone who can help me.
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@Ger43 I have a Race 1 (and Race 2)… the Race 1 has been great, with none of the distance loss / trimming of the Race 2. Lots of comparisons of features online, but from my practical experience, what I’m most concerned about is accurate ascent/descent, and accurate distance. The Race 1 is great in these regards.
