superposition: (Through hell and high tide)
Qubit ([personal profile] superposition) wrote in [personal profile] abheirrant 2020-05-05 08:57 pm (UTC)

[ Baby steps! The image, of course, does not bite. Or respond in any way. See, not all technology is out to get you! ]

Hm. "Dead reckoning" in more ways than one. [ Cause... cause if you get it wrong, you're dead. It's mildly amusing, okay. ]

Not quite the level of precision I'm looking for, though. You'd need a proper survey - manual, or via satellite, or a barometric altimeter, properly calibrated, of course. But let's say that's been done, you have that data. Now you can express any position on the planet as a vector in a spherical coordinate system.

[ With his finger, he draws a line connecting the center with the dot on the surface. The surface end has an arrow. ]

The components being, of course, latitude, longitude, and magnitude - your absolute distance from the center of the Earth. Which is preferable to mean sea level, since technically the planet is an oblate spheroid, not a perfect sphere.

[ Still following? Good, cause he's moving right along. ]

So now, let's say you want to be somewhere else. [ He looks up the target coordinates on his watch, and does the math in his head while he's talking. ] All you need to solve for is the transform between this vector and the new one, and that's basic linear algebra.

[ Plugs in his answer, and voila - the vector swings over to a point in central Europe. Qubit smiles, self-satisifed. ]

Child's play.

Post a comment in response:

This account has disabled anonymous posting.
If you don't have an account you can create one now.
HTML doesn't work in the subject.
More info about formatting