On 3 Sep., 01:02, "achsofr...@yahoo.com" <dkw12...@yahoo.com> wrote:
> On Sep 2, 1:22 pm, "Jon G." <jon8...@peoplepc.com> wrote:
>
> > The satellite signals its coordinates and time stamp to the receiver, which
> > is enough information to determine the distance from the satellite to the
> > receiver.  When this is done with 3 satellites, the location of the receiver
> > can be found with a little math.  This math is propounded at the web page,
>
> >http://mypeoplepc.com/members/jon8338/roots_to_polynomials_and_power_...
>
> Seems like you could locate a point with only two satellites provided
> the satellites or a person could determine the satelites poisition
> relative to the other single satellite. dkw

One satellite can restrict your solution space of possible positions
by one dimension.


Theoretically ...
If you know nothing, you need 4 satellites to determine position and
time,
if you know a bit more (e.g. have an exact clock) 3 satellites
suffice,
if you know the exact time AND the fact that you are 10000ft above
ground 2 satellites suffice.
If you don't know the time but know that you are on route 66, 2 might
suffice at well.
If you know you're at 754 Evergreen Terrace, no satellites are needed
at all unless you want to know the time.
Of course in all scenarios, additional satellites provide better
accuracy and fault-tolerance.
Also, some of these methods may reduce the solution spce to zero-
dimensional,
but not to a single point. Thus knowledge of the approximate
whereabouts i shelpful as well.