Updating satellite orbit data suunto
A variable error is added each 24 hour period, meaning that positional accuracy will be perhaps three meters one day, two the next, and somewhere in between the day after that. Certain high-technology civilian GPS solutions (like differential GPS) can correct for this error, but it’s impractical (and not really necessary) for hiking purposes.
After all, if you can’t find something within a few meters of where you are, you probably have other, more pressing problems.
The middle shows the GPS satellite constellation and in this “simulation” mode, it’s showing good signal strength from all satellites, which is not a real world occurrence!
Civilian GPS is generally accurate to within a few meters.
This post just discusses GPS, though you can buy receivers for the other systems too (and some will take data from more than one, like the Garmin e Trex20/30 which can connect to GLONASS). The top right hand box shows “3m”, the predicted accuracy.
The number 636m in the middle right is the current elevation.
Once you can do that, it adds a welcome margin of safety and convenience to your trips. More sophisticated versions, like the one in most modern cars, can use GPS data alongside maps to give you route information (turn left in 50 meters…). The simple version is that there are 31 satellites up in space, and at any moment from any point on earth, at least four of them should be overhead (usually more, and the more the better).
The most basic way is to read off the position data from the screen, and then look on a map to see where you are.
Though far from expert, I’ve had a bit of experience using GPS, including to save my bacon on at least one occasion.
The trick with GPS is to know how to survive without it. In its essential form, it is a system that can tell you, with great accuracy, where you are, and which way to travel from there to somewhere you want to be.
As always, you also need to use your other navigational equipment – notably your eyes and brain – to locate your position and the best route to your destination.
These are the 1990s-era US military handheld GPS receivers.
Please, if you backcountry recreate in Colorado, do so with CORSAR.