2 questions really: What functions involve the GPS in the Phantom 2? Initial lift-off location fixing (for use in the GoHome function) current location fixing (to inform the GoHome algorithm... but apparently *not* used to keep the model in dynamic station keeping???... I was curious on this because I had expected the model to have a shot at holding-station during a flight. the model will drift downwind without apparently making autopilot efforts to counter this drift. both switches on my handcontroller are in fully UP position - is this normal?) what else is the GPS used for?