How the length of the six is measured instantly in cricket? What technology do they use?
Radar gun is used to calculate the bowling speed in cricket.A simple example showing the use on http://www.bigbro.in/blog/how-is-the-bowling-speed-and-lengthdistance-of-the-sixes-hit-in-cricket-measured/
How it works?
Radar gun is the current or present technology to calculate the speed of bowl. Radar gun has both radio transmitter and the receiver. This device works on the principle of "Doppler effect." It sends the radio waves to the receiver. They emit a radio signal in a narrow beam and receive the same signal after it bounces from the target particle.
Hawk eye method It uses six specially placed cameras around the ground to track the path of the ball, from when it was released from the bowler's hand right up until when it's dead. with the combined effect of these six camera's a 3-D image is formed and is used to measure the speed of the ball bowled.
This same technology is used to calculate the distance of the six hit by the batsman.
First they calculate the speed of the ball after hitting the bat taking distance as 22 yards (changing it into meters) and then record the time till the ball crossed the pitch by d=s/t then they record the time till the ball has stopped outside the playing area then again they calculate the distance by d=s/t . this is how it is calculated
(all calculations are based on the assumptions that speed of the ball remains the same )
Actually its a good question.I just find these answer with these reference.
I can present