GPS signal loss

http://diydrones.com/profiles/blogs/details-on-how-iran-may-have-used-a-gps-override-spoof-to-capture?id=705844%3ABlogPost%3A738346&page=2#comments

Looks like they need to upgrade their nav algorythms to detect a spoofed gps and use dead reconing and compass to get it back over freindly teritory. Install a radio direction finder and have it track back home to a beacon to get it close enough to get a direct radio link and land it. Infact a good INS system could easily get it home with out any outside navigation signals