NFL open to goal line technology ..
By Martin Rogers
The National Football League may soon have the option of using a version of soccer's new high-tech, decision-making technology to help speed up disputed touchdown calls.
Lengthy reviews on whether a ball has crossed the plane for a six-pointer could be a thing of the past if the NFL decides to implement something similar to soccer's goal-line review system.
"We have looked at this type of emerging technology and would not rule out using it at some point in the future," NFL spokesman Greg Aiello said via email.
The system is an adaptation of the Hawk-Eye technology that has long been used in tennis to determine whether a ball is in or out. In its soccer guise, an encrypted signal is sent within a second to a watch worn by the referee, informing him if the whole of the ball has crossed the line for a goal.
Paul Hawkins, the inventor of Hawk-Eye, admitted his company had spoken to American sports leagues but perhaps understandably did not want to go into detail about the nature of the talks.
"There are ways we could assist in a number of American sports where there is a desire to get the officiating decisions correct," Hawkins told Yahoo! Sports.
Soccer's governing bodies were long resistant to the use of technology, fearing it could slow down the game, and imposed the "one-second" criteria on companies bidding to be used by major leagues and in international tournaments.
Hawkeye was the provider selected by the English Premier League and rolled out its service on the opening day of the season last Saturday, coming into use to rule upon a close call during Chelsea's victory over Hull. Fans, players and coaches alike were impressed with the speed and accuracy of the system.
"That comes from the fact that there is no human element," Hawkins said. "It is based on automatic tracking, as soon as the ball goes over the plane the signal is sent. … There are no subjective decisions."
Hawkeye uses a series of seven high-frame-rate cameras strategically positioned in the stadium, as well as vision processing techniques, to determine the exact location of the ball. The cameras work in tandem to give the central system a 3D image of the ball's position at any given moment in its movement.
According to Hawk-Eye, images from each camera "are processed to find the ball within the image and also identify areas which are definitely not the ball."
"Control software" collects the information in order to track the ball within the goal area. When it detects that the ball has crossed the goal line, it sends a signal to the official's watch.
Interestingly, the technology also tracks near misses, sending a signal to the referee that the ball did not cross the line in a close incident.
"The system is millimeter accurate, which ensures that no broadcast replays could disprove the decision," Hawk-Eye explains. "The system accuracy is not affected by any variances in the painting of the goal line or if the posts are not perfectly vertical."
The nature of the NFL makes it more likely that the ball would be obscured by the carrier or defenders. However, the technology is able to accurately gauge the location even if only part of it is visible on two of the seven cameras.
Furthermore, the technology is able to remove players from the image, enabling a definitive shot that could be broadcast on stadium screens and by television broadcasters.