You are welcome with your UAV in Qatar, but you have to arrange a permit from the Qatar Civil Aviation Authority (CAA)
If you dont have a permit in advance, your UAV wil be conficated when you are entering the Country.
Maximum take-off weight: No limit
Maximum hight: 122 meters / 400 ft
Maximum horizontal distance: keep visual contact with the UAV
Distance Airports / Heliports: 5 km / 3.2 mi.
Night flights: Prohibited
Prohibited: not in the neighborhood of military , ships, people, animals, government buildings, beaches.
Useful link: Qatar Civil Aviation Authority (CAA)
Contact information: firstname.lastname@example.org / +1 297 583 2665
Update February 2019: UAVs are still confiscated at the border if you don't have a permit from the Qatar Civil Aviation Authority (CAA)