[aprssig] garmin gps and compass heading

[Gregg Wonderly]

Richard Amirault wrote:
> Of course a GPS knows it's own position independant of orientation, but 
> that's not the problem, the problem is telling you where (left, right, 
> back, forward) the place is that you want to go.

A GPS, without a compass, can not tell you a direction when it is still.  A 
compass has to be present to provide a direction, when you are motionless.  When 
you are motionless and your GPS includes a compass, the orientation of the 
compass defines the base of all directional vectors available.

Gregg Wonderly
W5GGW