Go look at the source code to one of the open source projects like OpenPilot,
they integrate accelerometers, gyros, magnetometers, barometric altimeter and GPS for their navigation system,
modern GPS chips also have anti-hijacking/jamming, eg SiRFstarIV GSD4t consumer device chipset,
and the off the shelf radio control kit can do encrypted spread-spectrum comms.
It is not trivial to stop one by jamming, a shotgun up close is way more effective