How can goal-line technology be used

Goal-line technology at the EM: What options are there and how it works

What has long been standard at Fifa and the DFB is now also being adopted by the European Football Association. Goal-line technology is to be used at the EM. Exactly which one has not yet been determined. Prof. Dr. Doris Danziger from the Department of Electrical Engineering and Computer Science explains which systems are currently in use and how they work.

Prof. Doris Danziger and the automatic gatekeeper, which was developed by students in the Department of Electrical Engineering and Computer Science. (Archive photo / Münster University of Applied Sciences)

Prof. Danziger, there are different systems for recognizing whether the ball is in the goal. Do you know which ones are being discussed for the European Championship and whether they have already been used in other games?

Yes, two systems are on the shortlist. With the goal-line technology "Hawk Eye", you can already see to the millimeter at Bundesliga games whether the ball was in or not. Here it is optically determined where the ball is currently located. “GoalRef”, on the other hand, which was already used at the World Cup in Brazil, locates him over the radio.


How do the different systems work?

In “Hawk Eye”, seven cameras are installed for each goal under the roof of the arena. These cameras continuously track the ball from different angles. If the field of view of one or more cameras is blocked by players or the goal post, the software combines the recordings from the other cameras into a complete image. When the system detects that the ball has crossed the goal line, it sends a signal to the referee.

In contrast to this optical system, “GoalRef” works in a similar way to the theft protection in department stores. A magnetic field is generated with antennas located in the crossbar. This registers when the ball approaches the goal line. However, it must contain a special coil for this. If he has crossed the goal line, the referee will also receive a signal here.

Both methods are safe. Only the technical effort differs. For the camera technology it would speak that recordings of the ball trajectory or the auditorium are also possible.


In their laboratory, students developed an automatic goalkeeper and a goal scorer. Do you also use goal-line technology there?

No, unfortunately not yet, but goal-line technology is already planned. First of all, however, the automatic goalkeeper needs to be improved. Because the striker has become too good, he always hits the corners on the top right or left. After that, automatic goal line recognition is being considered.