Touchdown or First Down? New Technology Tracks Football's Position in 3D Space

Officiating in football, especially in the National Football League (NFL), is no easy job. But referees will be pleased to know that researchers from North Carolina State University and Carnegie Mellon University, in collaboration with Disney Research, have developed new technology able to track the exact position of a football in 3D space using low-frequency magnetic fields.

The game has already been revolutionized by slow motion instant replays and the ability to challenge a play, but this new technology would eliminate the need to challenge a ref's call in instances that involve the ball's positioning.

The "Localization with Magnetoquasistatic Fields and Complex Image Theory" project sought to determine the position and orientation of a light-weight, low-frequency transmitter using quasistatic magnetic fields in situations where the ball is blocked from view - in this case, during crucial first down or touchdown plays when it may be hard to get in good viewing position.

The researchers placed a low-frequency transmitter in the football. The transmitter - within the standard deviation of accepted professional football weights - induces a quasistatic magnetic field that is sensed by antenna receivers stationed around the field.

"With at least five unique measurements of the magnetic field, the three-dimensional (3D) position and orientation of the ball can be determined using complex image theory to account for ground effects," wrote the Disney Research team. "This system has several advantages including immunity to multipath propagation, unaffected by line-of-sight occlusions caused by groups of people, and minimum complexity on the person/object to be tracked."

Researchers tested a prototype of the football at a college-level football practice, which can be seen in this video. They hope this device will be helpful in pile-ups, low-visibility weather, or other instances when a referee's view is obscured, but the technology stills needs some fine tuning. They are trying to get the precision down to half the length of a football, according to a press release.

The study, led by Dr. Darmindra Arumugam of NASA's Jet Propulsion Lab, was published in the IEEE Xplore Digital Library on May 29.