GPS Accuracy

Really wanted to love the Fenix 5 as I think the connect app is great and they are user intuitive, but I cannot fault my Suunto Ambit 3 Peak really, the thing just works every time, bang on!

Well, I hate to bump this thread back to the top when it already hit page 2, but I think this should be looked at.

I walked around a small lake today with some open areas around it, so I thought why not test out the accuracy of Ultra Track. I loaded the walking app on my watch, set GPS to Ultra Track and started to walk. About a third of the way I saw a dead fish in the lake which I wanted to get a closer look at so I paused the activity, spent about two minutes at that spot and then continued the activity all the way around the lake. Let's take a look at the activity:

https://connect.garmin.com/modern/activity/1635876998

As you can see, for some reason the GPS stopped right where I paused the activity and didn't pick up when I continued. What is even more astounding (apart from the rather spotty track; the beginning is spot on but I never left the path next to the lake) is that in Connect it says that the walk was 1.65km long, but when you load the track into mygpsfiles or Google Earth you can see that it is really only 0.5km long and stops where I paused it. Did Connect simply auto-guess the pace for the rest of the activity since it was still running but GPS stopped? And why did the GPS not continue tracking? I'll try tomorrow if the GPS not continuing is a bug in the walking app when you pause it.

What do you guys think?

Just tried the walking app again in my neighbourhood on a short 10min walk and can reproduce the same bug as yesterday - the distance seems somewhat accurate in Garmin Connect but the track stops exactly where I paused the activity about halfway through. Can anybody else reproduce and confirm this bug? Auto-Pause was disabled and GPS was set to Ultra-Track.

Any reason why you are using ultra-track for a short walk? I would report the bug to Garmin, but I'd also turn on normal GPS +/- GLONASS and see if the bug persists.

Just tried the walking app again in my neighbourhood on a short 10min walk and can reproduce the same bug as yesterday - the distance seems somewhat accurate in Garmin Connect but the track stops exactly where I paused the activity about halfway through. Can anybody else reproduce and confirm this bug? Auto-Pause was disabled and GPS was set to Ultra-Track.

So I've just done a quick walk around the block using the Hike app set to UltraTrac (so won't be a perfectly pretty track - in case anyone wants to leap to some GPS inaccuracy conclusion). In the picture below the blue arrow is the point at which I stopped, hit the start/stop button, selected resume later, waited a few seconds with the F5 in normal watch mode, hit the Start button, waited for the green GPS lock ring to appear, and then selected the Resume option. You can see the track carried on recording fine. The only thing I can think is if you are not waiting for the GPS lock green ring to appear before trying to resume.

" />">

[Before anyone asks, I've not shared the link to the activity on Garmin Connect as, whilst I'm sure you are all decent folk, I don't want to publish where my front door is]

Can't have been too far from my front door in the early '90s, on Woodbank Drive. (I feel safe revealing that now, what with it being two cities ago).

Any reason why you are using ultra-track for a short walk? I would report the bug to Garmin, but I'd also turn on normal GPS +/- GLONASS and see if the bug persists.

No particular reason, had the time and since I already tried out GPS 1 sec and GPS/GLONASS 1 sec while running I thought why not test out Ultra Track as well.
Will do, is the mail adress still [email][email protected][/email] or is there a different way to go about it?

So I've just done a quick walk around the block using the Hike app set to UltraTrac (so won't be a perfectly pretty track - in case anyone wants to leap to some GPS inaccuracy conclusion). In the picture below the blue arrow is the point at which I stopped, hit the start/stop button, selected resume later, waited a few seconds with the F5 in normal watch mode, hit the Start button, waited for the green GPS lock ring to appear, and then selected the Resume option. You can see the track carried on recording fine. The only thing I can think is if you are not waiting for the GPS lock green ring to appear before trying to resume.

Thank you for testing it! There are a couple of things that I did differently though: I didn't use the Hike app but rather the Walking app, which I had to manually install from the Connect mobile app (More > Garmin Devices > fenix 5 > Connect IQ Apps > Applications).
Secondly I did not select Resume later but simply waited on the pause screen for a short period of time before selecting Continue. Your results don't surprise me since selecting Resume later will result in the watch disconneting the GPS connection and later reestablishing it when you choose to continue. Staying on the Pause screen should hold the GPS connection upright, which to me it doesn't seem to do.

I see. A bit dark outside now, but if I get the chance I'll try to replicate your scenario tomorrow morning whilst I'm waiting to start a 5km Canicross race. The venue is next to some lakes, so I might even be able to replicate that bit ;)

Edit (next day): I've done a couple of test loops this morning and I did see the problem that @jiminar has described on one of the two activities; during a Walk activity, GPS set to UltraTrac, when you press the start/stop button to pause and then resume the activity a few seconds later, the GPS tracking/recording stops but the pace and distance accrual still works. I',m a bit rushed today to post further details (tracks etc).

@jiminar, it might be worth you emailing your .fit files (direct from the watch) with an explanation to the [email][email protected][/email] address (from the Chronos 5.52 beta thread https://forums.garmin.com/showthread.php?372308-Fenix-Chronos-5-52-Beta&p=960725#post960725, it seems the Garmin dev folks do seem to be monitoring that email address for issues/bugs).

2º Training with fenix 5. Today Trail Running. GPS + Glonass. record 1 seg. Cloudy.
Fenix 5 (today) vs Fenix 3 (January)

Very good both but fenix 5 excelente accuracy. I am very happy.

Fenix 5:
https://connect.garmin.com/modern/activity/1638805190
Fenix 3:
https://connect.garmin.com/modern/activity/1537414985

An update on my FR235 vs F5 comparisons.

No change since last week really, the F5 overestimates by a tad less than 1% which generally translates to a 3"/km difference in pace. I've pinpointed the problem to "wobbling" tracks as evidenced by the notable differences between the track on the way out and the way back, something that affects the FR235 a lot less. There are many examples like the one I posted last week :



The interesting exception is on a track where the F5 did a lot better than the FR235 at "hugging" the track, possibly thanks to they gyroscope ? The FR235 was particularly poor the day I did the comparison though with 800s coming in at 840 meters on average vs 825 meters previously. The F5 was around 825 meters. I'd forgotten my footpod but that wouldn't have an impact on overall distance normally, especially on teh FR235 where you can't use the footpod for distance, unlike on the F5.

Hey WEBVAN, are those tracks and pictures from Garmin Connect? Would you mind plugging the gpx file into Google Earth and looking at the same section there? The reason I ask is because when I compared the same track in Connect vs Google Earth I noticed a difference like night and day. Take a look at the pictures below.

" />">

" />">

I think this might be because Garmin cuts out some GPS Datapoints on the map to make their webpage quicker and more responsive, resulting in those cuts and overall rather sketchy tracks. (Correct me if I'm wrong, no expert on this whatsoever!)

Also I tried the Walk app today with GPS and GPS/GLONASS and the watch continued to track me, so at least if you are using GPS this bug doesn't persist. Wrote Garmin an email about it yesterday but since it's the weekend I don't expect them to respond at least for a couple of days.