Hi Lisa,

I'll answer with a question: do you really need to model a GPS receiver (e.g. error modeling)? If you only need to assert node position, assuming you are able to conveniently address each node and have defined a mobility model for those nodes, something such as:

Vector pos = yourNode->GetObject()->GetPosition();

should be more than enough to obtain the coordinates of your nodes. Of course, if one objective of the exercise is to model a GPS receiver, that won't be enough.

-- Regards