Suunto 9 with the recent GPS firmware was among least accurate GPS watches in today's 25K trail race

[fazel]

Here is a comparison from my long run through Mohican State Park in Ohio. Ambit3 Peak is in orange, Suunto 9 in green using GPS + BeiDou based on my pre-run recon using Trimble GNSS Planning. The two are of comparable quality IMO (you can see the dotted trail peaking out a bit on both tracks in places). The MTB trail I ran is tree covered throughout. Weather conditions represented by additional photo.

[sky-runner]

@fazel How did distances compare between A3P and S9B?

[freeheeler]

@fazel
@kabzior
yes, in rare situations it is off “a bit”… but I’ve never seen the watch taking a nap in the middle of an activity, like mine did

[fazel]

@sky-runner well, I had the 9 connected to a Stryd so not apples-to-apples. 38.57 km for the 9 and 37.14 km for the Ambit. The trail is officially 24 miles (38.6km) long, so the Stryd performed excellent. I know from experience riding it on the MTB that GPS always measures low.

[Dimitrios Kanellopoulos]

@fazel you can see the distance without stryd for pure GPS points (also ommiting the fused speed that the watch applies ) if you like on QS

[fazel]

@dimitrios-kanellopoulos oh - cool. How do I do this?

[Dimitrios Kanellopoulos]

@fazel on the “detail statistics” look for GNSS distance. That is the distance of point to point calculated via the Vincenty method. Its not perfect and sometimes not better than the watch does.

However: You are comparing apples to bananas if you compare GNSS distance vs Distance. That is because you can have a tunnel for example or a difficult GPS terrain were the watch might draw a straight line , and you were actually ie traversing or a tunnel with turns. Consider a snake tunnel and using stryd. Exit to entry distance would be smaller than stryd. And your watch has similar algos with Stryd when GPS is lost or for instant speed etc. Its called fused speed. The watch can without GPS give you a very good distance estimate. That GNSS distance statistic would not.

So I would compare GNSS distance of Ambit vs S9 GNSS distance to see what their GPS recorded approximately.

[fazel]

@dimitrios-kanellopoulos awesome. @sky-runner here’s what I see, GNSS to GNSS.

9 Baro: 38.15 km
Ambit3: 37.23 km

[freeheeler]

@fazel
and these are awesome numbers! …in many ways!

[fazel]

@freeheeler thank you!