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GPS Accuracy

Former Member
Former Member
So it begins.

I will have mine Fenix 5 on Saturday and will start doing comparisons to an Ambit 3 Peak. I don't have an F3 to directly compare to as of now.

Anyone have an F3 and F5 to compare?
  • I'm pretty sure they are aware of these reports, the same like for F3 in the past. They just ignore it and think it's good enough, because the devices sell very well, so why bother because of minority who cares.
  • I agree on the watch, but are you saying you do not think Garmin Connect does any post run processing (pace chart for example)? If it does and only has a smaller data set then how can it be as accurate?


    In this case, GC definitely doesn't show what is displayed on the watch, but may well display what is recorded on the watch; every recorded point has a speed in m/s associated with it in the FIT file. The display is presumably this value converted to a pace and rounded to the nearest 5 seconds; the speed is definitely not quantised like that. I've done a quick plot of speed extracted from a FIT file and converted to pace and it looks exactly like the GC plot, except very slightly increased fine noise, which is probably because GC as ever is not plotting all the points (I'd post it but don't have time to clean old images out and I've used my allocation up :) )

    So no, I don't think it is post-processing, but rather relying on what's in the watch, and with smart recording there would be fewer values to plot therefore less noise on the sub-5-second timescale, which is probably filtered out anyway.
  • Former Member
    0 Former Member over 8 years ago
    I did receive my F5 sapphire today and took it for a 10km test run (30% tree covered, 50% open field, 20% urban roads with buildings on both sides) testing it against the device i was upgrading from: The Forerunner 225. Small Disclaimer: The FR225 of course only does GPS and only does smart recording, so never ever will i say that it is the perfect device to compare the F5 to. For me it is relevant because i want either consistency in my data or data of better quality, be it live or for post-run analyzing, especially when paying THAT much for the upgrade.

    That said, 1-sec GPS&GLONASS enabled, for 98% of the run, the F5 did a spot-on job. Saw some HR quirks, and some minor pace quirks, but nothing out of the ordinary, EXCEPT for that one 200m-stretch next to a building where the F5 suddenly was entirely off with the pace, going up to 25 mins/km, while the FR225 didn't care at all. After the run i looked at the data, and the F5 definitely did crazy tracking stuff there. Here is the comparison image:



    The questions for me are: Would using the smart mode on the F5 eliminate this? How do other 1sec GPS & GLONASS devices by Garmin deal with this problem which obviously is sudden heavy sensor noise leading to faulty tracks?

    Also - non GPS related - can someone explain to me why Garmin cared to include a temperature sensor at all, when you get things like this:



    I get that subtracting the influence of body warmth and other sources is pretty much impossible, but why is the sensor 6-10°C off the real temperature even after letting it rest on my table for an hour? Why include that sensor at all?

    It's gonna be a tough 2 weeks to decide whether i am going to keep this device, because there is also so much i love about it, don't get me wrong. But for that much money it has to be as good or better than my FR225 at the things the FR225 did, i don't think that is too much to ask.
  • Former Member
    0 Former Member over 8 years ago
    My F5 is much worse in terms of GPS accuracy than my FR935. That Exo Antenna is rubbish, just a marketing thing. Yes the F5 is a looker but boy FR935 trashes it in terms of accuracy and general signal stability.
  • Also - non GPS related - can someone explain to me why Garmin cared to include a temperature sensor at all, when you get things like this


    The temperature sensor is needed to calibrate the barometric altimeter. Why they care to record the temperature from the internal sensor into the activity FIT file is a mystery since it's completely useless.
  • Former Member
    0 Former Member over 8 years ago
    My F5 is much worse in terms of GPS accuracy than my FR935. That Exo Antenna is rubbish, just a marketing thing. Yes the F5 is a looker but boy FR935 trashes it in terms of accuracy and general signal stability.


    double....
  • Former Member
    0 Former Member over 8 years ago
    My F5 is much worse in terms of GPS accuracy than my FR935. That Exo Antenna is rubbish, just a marketing thing. Yes the F5 is a looker but boy FR935 trashes it in terms of accuracy and general signal stability.

    Could you publish 935 and F5 tracks for comparison? The tracks I've seen looks pretty similar to me. The tracks and distance from my F5S is solid, it's the pacing when running that seems to be the the problem....
  • Former Member
    0 Former Member over 8 years ago
    Here are two almost identical runs with F5 and FR935:

    https://connect.garmin.com/modern/activity/1648811019
    https://connect.garmin.com/modern/activity/1679264905

    The total distance is almost the same but F5 is way off the track usually towards my left in the direction of running. Sometimes is 15-20m away from were I was actually running.
    Both watches GPS+GLONASS, 1s recording.
    These runs were in very good conditions, clear open sky, no foliage. I'll try to find similar runs in more demanding conditions.
  • Here are two almost identical runs with F5 and FR935:

    https://connect.garmin.com/modern/activity/1648811019
    https://connect.garmin.com/modern/activity/1679264905

    The total distance is almost the same but F5 is way off the track usually towards my left in the direction of running. Sometimes is 15-20m away from were I was actually running.
    Both watches GPS+GLONASS, 1s recording.
    These runs were in very good conditions, clear open sky, no foliage. I'll try to find similar runs in more demanding conditions.


    Both need to be on Firmware 2.90 to be more accurate though. Ones on 2.40 the other 2.90.
  • Here are two almost identical runs with F5 and FR935:

    https://connect.garmin.com/modern/activity/1648811019
    https://connect.garmin.com/modern/activity/1679264905

    The total distance is almost the same but F5 is way off the track usually towards my left in the direction of running. Sometimes is 15-20m away from were I was actually running.


    I zoomed into 10m on both maps, and TBH, I'd be hard pressed to say one was remarkably better or worse than the other. The pacing is more erratic on the 5, but the tracks from both watches seems to have areas where they struggled more than than other (and generally both look decent to me).