[aprssig] garmin gps and compass heading

[Jan T. Pharo]

"Richard Amirault" <ramirault at verizon.net>, Fri, 28 Apr 2006 20:54:57
-0400:

>A GPS expects to be held, face up, with the "top" of the unit towards the 
>direction of travel.  For instance if you are in a car, moving forward, and 
>the GPS says that the next waypoint is 90 deg to the right.  THEN, if you 
>stop and backup the car WITHOUT moving the GPS in any way .. the GPS will 
>tell you that the waypoint is now 90 deg to the LEFT!! so long as the car is 
>still moving backwards.

The GPS will show direction independently of its own orientation. It's
the difference in its position (lat and long) that is significant. And
at least my Garmins are telling me which way to turn related to how it
is moving, not which end of the navigator happens to be "forward" in
this movement.

-- 
73 de Jan, LA2BBA
Hvaler, Norway