Related

GPS: Completely unacceptable

Dennis.stevens1982
over 4 years ago

Hey all,

I have posted my problems with the Fenix 6X Pro in German Forums here and here. Maybe I get some new advices here.

First things first:
FW V5.00
GPS V2.7
3D-Speed: OFF
3D-Distance: OFF
Data recording:Every second

When I used the Fenix for the first time, it ran on FW V4.30.0 and had acceptable performances in measuring distances. On a ~12.5km run it measured for example between 12.01 and 12.1 km. Which was in accuracy comparable to the Forerunner 245 which I have used before- and really OK for me.

My focus in running are the pace and the heart-rate. Which are the most important parameters in addition to my own body sensation. If I run 12km in 5:25 with a HR of approx 160 I am fine. If I feel great after the run, the training was perfect for me.

The pace is a function of time and distance - and now on the Fenix the distance is a huge problem since update to FW 5.00.

On 15th December 2019 (my Fenix received V5.00 the day before) the GPS accuracy became really bad. But each time I follow advices like waiting 25 minutes until the Fenix has updated her satellite-almanach or updating to GPS V2.7, in the first session after such updates the Fenix delivers accurate distances. But each following training it gets worse.

Examples:
1. updating the satellite-allmanach: Distance 12.06km, time 1:05:15, pace 5:25min/km
2. next training (still with GPS V2.6): Distance 11.78km, time 1:08:45, pace 5:50min/km
3. After Update to GPS 2.7: Distance 12.06km, time: 1:07:07h, Pace: 5:34 min/km
4: Next training 11.87km in 1:09:50 h, pace 5:53min/km
5: today 11.37 km, time 1:07:25h, pace 5:56min/km

The distance I run is always the same: 12.5km

Training 1 and 3 proof (to me) that after an update the Fenix works perfectly.

Training 3 and 5 reveal that it is not possible to rely on the pace. Since accuracy (690m deviation) is far beyond acceptable, two trainings in the same distance, with a deviation of 18 seconds are calculated to have a deviation in pace of 22 seconds. And such is not acceptable. 22 seconds in pace can make the difference between an easy aerobe training and an hard training. VO2Max depends on the pace and the heart-rate. In Training 3 the VO2Max was calculated with 49. In training 5 with 47. But the diference in heart rate was only 4 beats.

Important: I do not care for calculated Vo2Max. I just wanted to show how the GPS-accuracy has impact on many other parameters in the device.

Based on my experience, my best solution would be to downgrade to FW V4.30.0. But I was told that this is not possible since I have to downgrade sensor-fw and other software, too.

Can anybody help me with that problem? At the momment sport is just frustrating. And the reason for that is a sportwatch. Unbelievable.

kind regards!

Dennis

Top Replies

All Replies

  • Former Member
    0 Former Member over 4 years ago in reply to johanwiren
    Yes, yes i am especially impressed with this route ... so many woods, turns and tall buildings!
  • 0 over 4 years ago

    Hello all,

    Just thought I'd bring my two cents.
    I have a Fenix 6 sapphire since end of august so I've been able to use every firmware update after they were released. Overall I've noticed a small improvement since early FW versions, but I've had both very bad and very good GPS tracks depending on the conditions.

    One of the worst tracks I had was three days ago, while taking a short run in a park near my house 
    https://www.strava.com/activities/3083279306

    The best one, on the other hand, was a 76K race I ran two months ago :
    https://www.strava.com/activities/2904357169

    The GPS track is spot on 99% of the path.

    The difference is, for this race, I waited on the starting line for maybe 45 minutes, so I had the opportunity to acquire a good signal for maybe 10 or 15 minutes before starting running. I think this is maybe the best thing to do if GPS accuracy matters to you so much. Of course I understand that it's not very convenient to wait for 15 minutes standing with the stupid watch pointing to the sky before you go for your run Smiley but maybe try to get a good signal before actually starting to move & run... 

  • 0 over 4 years ago in reply to RISBAC

    https://quantified-self.io/user/KyPxAPiJncaEuQ6TkohlFzPkcln2/event/detT3XHTfX039FCZt3Zo

    fenix 6x vs forrerunner 945

    fenix 6x - HRM tri strap, 945 wrist HR

    both: GPS+GLONASS 1s

    both on the left arm

    fenix 6x: 12,24km (correct distance (strava): 12,43km ); F945: 12,36km (correct distance (strava): 12,45km)

  • 0 over 4 years ago in reply to tironas

    Now that's a good test :) I can't see the QuantifiedSelf data, it shows my own account if I connect to  your link

    But it already confirms what we say : the Fenix is more autocorrecting than the 945. 


    Can you share them on QuantifiedSelf ? (click on the two runs, merge them, then on the merged activity, you click on the lock to make it public, and share the link). Or the TCX files in a private message if you prefer. 

  • 0 over 4 years ago

    One more comparison for fenix 6x with different GPS reception settings. The only difference in settings is that the first run was with GPS - only and the second - with GPS + Glonass.

    The same route, which according to both GPS files is 7.35 km. This is a bit too much, because it should be about 7.2-7.3 km. I know this area very well because I have run there hundreds of times.



    GPS only is quite OK but GPS + Glonass is way too short. The difference in distance is 5%!

    Why then is the possiblity to set the watch on two groups of satellites if it doesn't work? This was supposed to improve signal reception.

    Do you have any ideas?

  • 0 over 4 years ago in reply to JacekZet

    I don't think it can use both at the same time. They use it mostly to have a position faster when you start, choosing the right signal from one of the two. I don't even think that they advertise it as "more precise". It's only to get a faster lock. And most reports I read say that Glonass doesn't improve the accuracy, it's often worse. So I'm sticking with GPS only.

    Then on top of that, the algorithm is "fixing" the distance too short. That's the real pb, since the GPS recording is often very acceptable and giving a good estimation of the distance. 

  • 0 over 4 years ago in reply to RISBAC

    I'm not so sure that the idea was only to improve fix by making it faster using the second satelite system.

    In the Suunto manual you can find that "To get better GPS tracking results when exercising in difficult terrains like e.g. in a dense forest, ravine or city with tall buildings, it may help to turn on additional satellite navigation systems such as GLONASS or Galileo if available in your watch."

    Of course we are talking about Garmin watches but I don't think that the differences are that Suunto assumes that it will improve tracking in difficult conditions and Garmin - that only a faster fix. It wouldn't make any sense.

  • 0 over 4 years ago in reply to JacekZet

    More or less the same is written in the fenix 6 manual: "The GPS + GLONASS or GPS + GALILEO options offer increased performance in challenging environments..."

  • 0 over 4 years ago in reply to JacekZet

    Then either it's marketing, or it's simply not working well. I read several tests, even the newest dual frequency options are not giving that great results. It's supposed to give 30cm precision, but it's not the case. Maybe it will improve, but they seem to say that the size of the antenna will be the limiting factor.

  • 0 over 4 years ago in reply to RISBAC

    Yes, it looks like. But for fenix 5x the change from GPS to GPS+Glonass improved tracking and accuracy.

    Something has happened and now it's only worse. Maybe it's the chip's fault, maybe the software...