How to choose GPS setting - GPS or GPS+GLONASS ?

How do you determine the best GPS setting for your area?

Here is where I'm at:
* Getting good results on both GPS and GPS+GLONASS. Both are within +/- 0.2 miles on my 8 to 12 mile runs.
* Not sure how to help quantify which GPS setting might give me better results
* Should I go by: 1) Overall distance accuracy; 2) Satellites in my area; 3) How the GPS tracks on the map; or 4) Some other way?

And I attached a satellite list for my area. Several GLONASS satellites – so I’m thinking GPS+GLONASS ?

Thanks for any guidance.

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0 Messner over 6 years ago

With the latest firmware You should also have the Galileo satellites option

0 xavier4or over 6 years ago

Yep - but I don't think I have any Galileo satellites above me? The phone apps says it does detect Galileo... (See picture)

I did have to look-up the QZSS satellite that was listed:
Quasi-Zenith Satellite System (QZSS) QZSS is a Japanese satellite positioning system.

0 tmk2 over 6 years ago

All global navigation system satellites (including GPS, GLONASS and Galileo) move around the Earth, so one day you may have more of them available, and on other days less. Unless you experience reception problems due to terrain or other obstacles, I'd leave just GPS, as additional systems will cost you more battery, and accuracy gain would be minimal anyway.

0 mcalista over 6 years ago

I agree with TMK2 It requires a minimum of 4 satellites to get an accurate fix. With a relatively open view of the horizon, you should easily be able to see 4+ satellites from any one of GPS, GLONASS or Galileo. Accessing a 2nd system is of little advantage in these circumstances (and will hurt battery life).

With an very obscured view of the horizon (eg. tall buildings, narrow valley), your watch may not able to access 4 satellites. Having access to a 2nd constellation of satellites will increase your chances of being able to access the required 4 satellites, and can increase accuracy.