Question on GPS + Glonass

Never mind the second question. Figured out I needed to create a hot key to get to widgets during an activity. I guess the Fenix just "pre designated" the down button as a hot key.

I don't much use GLONASS. It was set up by Russia and the orbits are such that it has better coverage in northern latitudes, where Russia is. I assume that it works best in far Southern Latitudes as well. But it doesn't seem to make much difference to me, in the southern USA.

I can see that it might be helpful in something like a ravine or among tall buildings in a city, because in that case the GPS unit can't see very many satellites anyway and the additional GLONASS satellites might improve the chances of getting the 4 necessary for a lock.

There's a widespread belief that adding GLONASS can DECREASE accuracy vs GPS alone.
http://fellrnr.com/wiki/GPS_Accuracy#GPS_and_GLONASS

Adding GLONASS is supposed to increase power consumption by 10% over GPS alone.

Regarding WAAS and the rest, I don't know which GPS units use that. I assume that draws even more power so it's probably only available to plugged in devices. But from a consumer point of view I don't know that it's necessary. If I was in the Air Force and wanted to drop a bomb on a terrorist, or if I was a civil engineer monitoring soil erosion, the extra accuracy would certainly come in handy, but when I'm running down the sidewalk, +/- 10 feet is good enough for me.

GPS units have become much more accurate since the days right after selective availability was removed and Garmin put out the first yellow etrex. They had other units before that but the etrex was a huge hit. I certainly remember being in the mountains and accuracies in the 100 meter range were not uncommon. You pretty much could use it to roughly pin yourself down on a paper map with a grid reader. Certainly recall places where we went, WTF, put the GPS in the pack pocket and used the map and terrain features to figure out where you were and how to get to where you were going.

Even now everyone better know map and compass and how to triangulate position. Even 5-6 years ago the way you got accuracy was with a bit quad helix antenna. Now the patch antennas seem to be just fine. I am blown away by how quickly this device gets a fix and how accurate it is [maybe because I have had GPS handhelds for over 15 years]. I think in my area {SE US} maybe the GLONASS would make sense in those mountain ravines when you have fewer satellites to fix.

Interesting techno geek article.

http://www.faculty.sfasu.edu/zhangy2/download/WAAS_GLonass_GPS_area.pdf