"ok.. here's how I did it.... not sure how you can.. I would need more details.

First I had a laptop and a gps unit on the ground, and one in the uav. Both units were Eclipse P320 GNSS OEM Modules by Hemisphere GPS. Both antennas were identical…"

"I had this running on a linux gumstix. The UAV gps data was no different than a trebile... it was just a serial input stream, that you could route to rtklib. (http://www.rtklib.com/)."

"If your lucky, some of the states offer access to the CORS network operated by the UN / NOAA / some states. the website for it is http://geodesy.noaa.gov/CORS/. I've got code somewhere that connects to it. It can work in real time if you have…"

"I did this with a pair of Hemisphere Crescent / Eclipse II receivers, and a Trimble ProXRT with all of the subscriptions at work. The 2cm is over a 5 minute time period, assuming you are in the middle of no where, and have an antenna from god, and…"