Strap a phone to it...
The GPS receiver only needs a view of the sky. Shield it (hemispherical Faraday cage?) from the ground, and build sufficient autonomy into the drone such that communication with the ground is only used to supply (encrypted+signed) new mission parameters, with some basic logic to determine what to do if contact is lost for too long. Continue with current mission until fuel/power drops to the point that returning home is required sounds sensible.
How much does a 3G/4G phone weigh these days? Write a little Android app that can output control signals to the drone, while pulling GPS coords and listening for new commands over data/wifi.
Biting the hand that feeds IT
