stowite:
GPS has a crude inbuilt compass so you will only need a separate compass if the GPS compass is not accurate enough for your needs.
No, GPS can give the bearing of the receiver only if it is moving and moving at a reasonale speed (walking
pace or more). A compass works for a stationary object.
You need a compass on the fixed node if its orientation is unknown, the local magnetic correction, the lat/long of both
nodes to compute the bearing.