For one of my coming classes I get a drone from the college and I had an interesting idea.

I've heard of a drone with a camera that allows it to follow you around in different modes.

What i want to do:
1. Get a GPS device (small and cheap if there is such a thing) that can broadcast its signal.
2. Attach a small raspberry pi to the drone that i can embed code in to make it follow me around.

What i need:
1. That small device that can broadcast its location over a signal or something of the sort (as to wear as a watch or stuff in a backpack or pocket and maybe attach to a mountain bike or something but I don't know of such a device.

Does anyone know of where I can get or find one? I've been googling but to no avail I haven't found anything.