maemo.org - Talk - View Single Post - N800 travel to space?

	Saturn	2009-09-12 , 23:25
	Posts: 1,648 \| Thanked: 2,122 times \| Joined on Mar 2007 @ UNKLE's Never Never Land	#18

Originally Posted by texaslabrat

...
Accurate altitude determination requires a solid 4-sat fix minimum (4 unknowns require 4 equations/satellites) though due to geometric issues altitude determination will have a larger error bar.
...

I would think the unknowns are 3 (i.e. x,y,z) but the fourth satellite might be needed to reduce errors from timing, approximations used in the algorithms to make the calculations faster or something similar.

Basically, my question is what's the fourth unknown?

Thanks.

Quote & Reply |