"John Bell" wrote in message . com...


Actually, my response to Ron Natalie was a little more than tongue in cheek.
It was somewhat of a combination of defensiveness and worry that I might be
spreading bad information. Ron's statement that my explanation of how GPS
works: "while one of the common ones often espoused
has no basis in reality. This is not how GPS works" has me curious.

The "overlapping spheres" model is NOT how GPS works. It's the same as the
stupid flashing light analogy for VOR. It perhaps gives someone some concept,
but it's not accurate at all. The way GPS works is to use pairs of satellites
to determine hyperbolids which are intersected with ones generated from other
pairs.