Related
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

935 Galileo Difference

GS
over 6 years ago
New thread to discuss performance difference with GPS + Galileo as compared with other options (GPS or GPS+GLONASS).

One run for me on road on usual route in Southeastern US, GPS + Galileo, and no perceived difference in elevation, track accuracy, distance or pace. Perhaps a little quicker to lock satellites before activity start but only perception. Really hadn't noticed a difference between GPS and GPS + GLONASS either, prior to update.

  • 0 over 6 years ago
    From Garmin, "To calculate your 2-D position (latitude and longitude) and track movement, a GPS receiver must be locked on to the signal of at least 3 satellites. With 4 or more satellites in view, the receiver can determine your 3-D position (latitude, longitude and altitude). Generally, a GPS receiver will track 8 or more satellites, but that depends on the time of day and where you are on the earth. " https://www8.garmin.com/aboutGPS/

    So, the more the better it seems which begs the question, why isn't there an option to use GPS + GLONASS + GALILEO or an "auto" option as Browner40 suggests above?
  • Former Member
    0 Former Member over 6 years ago
    So, the more the better it seems which begs the question, why isn't there an option to use GPS + GLONASS + GALILEO or an "auto" option as Browner40 suggests above?


    One would think so. Maybe a limitation of the hardware or SW/FW? If possible, maybe added later?
  • 0 over 6 years ago
    From my understanding, Galileo is supposed to support 1m accuracy where as GPS and GLONASS are each 5m. But part of the Galileo standard involves 2 channels and I believe Garmin still only uses one. That is almost certainly the case on the Garmin 130 which has supported Galileo for awhile.

    As for accuracy, satellite orientation plays a big part in accuracy. If you have 8 satellites directly overhead, that doesn't help much with accuracy. Accuracy depends on triangulation and straight up doesn't give much triangulation. A good signal strength from a satellite at more of a horizontal orientation will help more with accuracy. But if you have tall buildings, trees, or mountains, they may block all but the ones directly overhead, negatively impacting accuracy.
  • Former Member
    0 Former Member over 6 years ago
    As for accuracy, satellite orientation plays a big part in accuracy. If you have 8 satellites directly overhead, that doesn't help much with accuracy. Accuracy depends on triangulation and straight up doesn't give much triangulation.


    This goes without saying. The problem for my location isn't satellites overhead. The problem is there isn't enough Galileo satellites in view to triangulate a good 3D view period. Until more satellites are available Galileo is currently useless for my location.
  • 0 over 6 years ago
    So, is there reason not to have a GPS + GLONASS + GALILEO option? More satellites (and better locations of the satellites) should mean 1) faster lock and 2) higher quality data, particularly altitude (3D). The question now I suppose is whether to select GPS + GLONASS or GPS + GALILEO. Given the number of operational satellites currently, GPS + GLONASS should win out in most cases.

    However, for those of us that are using GPS + GALILEO now, is anyone noticing a difference? I have not yet but of course limited data so far.
  • 0 over 6 years ago
    I did a run yesterday with GPS+Galileo. Cannot see any improvement in track quality compared to GPS only (central europe, flat, good weather). Might be different in the mountains or otherwise difficult environment.
  • Former Member
    0 Former Member over 6 years ago
    Did my first run with Galileo support. No improvement and even worse situation under bridges with jumping tracks as a result.

    I switch back to GPS only. I'm glad that the 935 is good enough with GPS only. If I still had my F5 with the mediocre GPS I would have waited impatiently for the update and would be very frustrated that there is no improvement with the additional Galileo support. Very happy with my 935!

    Central europe
  • 0 over 6 years ago
    Not seeing much of a difference here either, then again I already had nothing tom complain using GPS only anyway so didn't expect much else... Looked at battery but only had 2 half our runs t compare. Also hardly any difference (0.1% or so, 2.65 vs 2.8) so yeah... just going to use GPS from now on.

    Maybe if I am going to do a proper walk I'll give them both a try, perhaps it adds something there
  • 0 over 6 years ago
    In my experience GPS+Galileo is slightly worse than GPS+GLONASS. Not by much and not all the time, but a few more clipped corners than usually. I generally have good tracks using GPS+GLONASS, so this was just out of curiosity. I'll switch back to GPS+GLONASS until Galileo is fully operational, I believe this is the reason why the results are subpar.