this post was submitted on 06 Mar 2025
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GPS literally triangulates your position using 3 satellites. It's how it works.
No, you need 4 minimum.
Two satellites intersection places you on a circle. (all points possible)
Three satellites intersection places you on two possible points.
The last satellite give you the exact location.
However, the 4th can be omitted if one of the 2 points is not in a sane location. (eg well below the crust). And it's trilateration not triangulation.
The reality is that your phone/device will use like a dozen satellites.
three sats determine your accurate position. the fourth is for clock correction only.
No.
Satellites project a sphere, you need 4 in order to get to a singular point. I've outlined each step. Fourth isn't for clock correction only. And even outlined why sometimes 3 is okay, but that requires additional logic that many gps devices sometimes can't compute, and even outlined that the vast majority of devices will use way more than 4.
https://gisgeography.com/trilateration-triangulation-gps/
https://www.gps.gov/multimedia/tutorials/trilateration/
Deleted your comment because you looked at the last image?
Edit: The images on the site depict the exact thing I've been referencing.
1 satellite = whole sphere of options.
2 satellites = a whole circle of options
3 = 2 points
4 = 1 point.