Calculate cardinal points from GPS?

[Philippe Guillebert]

f4lken wrote:
> I think that a GPS receive some information about cardinal point... So 
> it will be more simple to read these information than calculate some 
> difference... But, as I say, I'm not sure :(
Hi,

No, it doesn't...The way to calculate bearing is to derivate your 
position over time to get a speed vector (Vx, Vy). You can then 
calculate the angle that vector form with North (simple trigonometry) 
and calculate current bearing (in degrees) or show a compass (same thing 
in a different referential).

The thing is, it works only if you're moving.


-- 
Phyce