Biggest Sixes Funda

Watching all the matches in T20I World Cup , there is this interesting part of biggest sixes statistic. Misbah-ul_haq has scored the biggest six at 111m so far. How do they measure these distances once the ball is out of the ground? If it is inside the ground , I agree that you know which stand it fell in and you know the distance from that stand to the center of the pitch, but how do you measure the distance traveled by a ball that is hit out of the stadium? - If I had to venture a guess , I would think that just like Hawkeye traces the motion of the ball from the bowler's hand , there would be a technology to track the ball after it has hit the bat and will extrapolate the distance based on the speed and elevation it was traveling, when it left the ground. The commentators at Cricinfo (read people who write the commentary while I keep hitting that F5 button) commented that it might be out of luck. Anyone knows how it is done?