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.
Phones already do that with cell towers. It’s called A-GPS (augmented GPS). Cell towers, wifi, and even bluetooth, are used in addition to GPS/GLONASS/Galileo signals.
I live in an area with a lot of iron. I cannot trust a compass to always point north. Generally I’ve had no problems in the woods: follow the trails that are on the maps, or at least stay close enough that you can always find them again and you are fine. (until of course you are not)
So… maps?
Triangulation could be more efficient than GPS, in terms of energy use and such
They should use that in GPS! /s
Triangulation of what, exactly? GPS already triangulates your position based on what it receives from multiple satellites, yeah?
Cell towers, in an urban area you’re typically within range of a couple.
Triangulation of GPS signals is what allows the System to determine your Position Global(ly)
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/
https://oceanservice.noaa.gov/education/tutorial_geodesy/geo09_gps.html
Phones already do that with cell towers. It’s called A-GPS (augmented GPS). Cell towers, wifi, and even bluetooth, are used in addition to GPS/GLONASS/Galileo signals.
Is that the difference between when something like Google Maps has your general location and when it has your specific location?
A-GPS works faster than GPS on its own.
Time to bust out the compass.
I live in an area with a lot of iron. I cannot trust a compass to always point north. Generally I’ve had no problems in the woods: follow the trails that are on the maps, or at least stay close enough that you can always find them again and you are fine. (until of course you are not)