The Hawk-Eye tennis officiating system is the first and only ball-tracking technology to have passed stringent ITF testing measures. The technology is now an integral part of the ATP, WTA and ITF tennis tours, featuring at over 60 events across the tennis calendar.
The professional game is won and lost on the smallest of margins. Players leave no margin for error in their practice, preparation or play. Why should line calling be any different?
The Hawk-Eye Officiating System is not only vital for ensuring that high pressure points do not fall prey to umpiring mistakes; Hawk-Eye brings the fans closer to the action. Spectators watch alongside their heroes and heroines on court as Hawk-Eye show whether a ball was in or out on stadium big screens and televisions at home. Hawk-Eye’s graphical representation of statistics bring a whole new dimension to television coverage and fascinates tennis fans worldwide.
Electronic Line Calling
Teams of Hawk-Eye technicians travel year-round to temporarily install and operate Hawk-Eye systems at tennis events worldwide. Up to ten different events can be occurring on any given week.Players have access to 3 incorrect challenges per set, plus an additional one in the event of a tie-break. The system is able to display the outcome of any bounce within 5 seconds of the ball landing, with the result being displayed to the players, umpire, fans and television viewers simultaneously. On average 30% of calls are overturned.
Accurate and Reliable
During ITF testing in 2006 Hawk-Eye passed a number of stringent parameters, meaning that it would be the first electronic line calling system to be officially accredited. Results showed the system to have a mean error of only 3.6mm when compared to a high speed camera located on the playing surface.
Since then, testing of the system is an on-going process at all events prior to main draw competition, including tests conducted outdoors, encompassing situations that take the following factors into consideration:
- Wind (and therefore camera wobble)
- Bright sunlight at different times of the day
- Shadows covering part or the majority of the court
- Dark or overcast conditions
- Artificial floodlights
Although the accuracy of the existing system has been proven to meet the ITF rules and regulations, the company is constantly developing and refining the system to raise the bar further still. Equally Hawk-Eye listens to feedback from customers and officials to ensure that Hawk-Eye remains the very best in the market in accuracy, reliability, speed and from a broadcast point of view.
Regarding accuracy specifically, it's interesting to observe high speed video footage (1000fps), similar to that obtained during ITF testing. You can clearly see the ball squash, skid and roll off the surface, spanning some 10cm before becoming air borne once again. If viewed from a regular broadcast camera (25fps), its clear that the viewer's perception of where this ball had landed will be influenced significantly by the limited frame rate and zoomed out field of view provided by live broadcast footage. In this example, it would be easy to argue from one end of the sequence to the other that the ball landed within 2mm of the back edge of the line, or at the other end of the sequence almost 10cm outside.
Not only does the system boast excellent accuracy results, the system needs to be extremely reliable - tracking hundreds of thousands of tennis balls throughout the tennis season. Although a protocol remains if the officiating system is not able to provide an answer with utmost confidence, this is an extremely rare situation, where onsite operators are not 100% confident in the accuracy of the system for that given shot.
The level of accuracy and reliability have been proven to be significantly better than any potential competitors, proven by the system remaining (after 7 years) to be the only accredited system.
How Does it Work?
2D (x,y): Vision processing is used to identify the centre of the ball within each frame of each camera. Camera movement is compensated for by also tracking the lines of the court.
3D (x,y,z): The system triangulates the information from each calibrated camera to provide the 3D position of the ball.
4D (x,y,z,t): This process is repeated for each frame so that the 3D positions of the ball can be combined to produce a single trajectory of the flight of the ball.
Hawk-Eye is now vastly experienced in working alongside TV broadcasters worldwide, providing challenged calls, close calls that the players opts not to challenge, calls that are not challenged, as well as an array of illuminating statistics to improve the overall viewing experience.
A great deal of software expertise had been expended on improving our Virtual Reality 'look' in 2012, meaning Hawk-Eye can tell even more of the statistical stories relevant to the match in hand. Hawk-Eye’s bank of graphics is constantly expanding as TV commentators and producers express different ideas and feedback. TV Commentator and Hawk-Eye Analyst, Jason Goodall remarks on the natural addition of Hawk-Eye statistics to sports commentary,
“I think the data that Hawk-Eye is able to capture and process in user-friendly form is invaluable in helping us all gain a unique insight into how the best players in the world are able to achieve all they do. Not only are we able to sit back and enjoy watching the world's best compete with one another, now with the help of Hawk-Eye we can also learn from them too."
Hawk-Eye’s latest innovation within Tennis is Player Tracking. Utilising the core ball tracking cameras, recent computer hardware and software developments allow player tracking data to be processed, analysed and converted to user-friendly information within seconds of the point ending. Hawk-Eye player tracking provides coaches with in depth information and a unique coaching tool to analyse movement and improve a player’s game.
By combining player and ball tracking information, Hawk-Eye is now able to visually and numerically identify all parameters of elite sporting performance, adding instantaneous scientific fact to previously unquantifiable parameters. The coaching tools and televised statistics continue to evolve as we adapt to the feedback from broadcasters, coaches and commentators.
Serve Speed Displays:
Data captured from our 10 core tracking cameras is analysed in real time to produce fast, accurate, and reliable serve speed information, a service provided at a number of the major tour events. This information can either be displayed within the large video walls typically used for the scoreboard/electronic line calling, or via courtside displays.
In order to maximise the potential of the stadium video screens (which are a requirement of the electronic line calling system), Hawk-Eye provide a managed service to produce the content of these video walls throughout the competition. Such content includes:
- Scoreboard (which can include additional information such as ''Challenges Remaining'', ''Match Time'')
- A video feed of the host broadcast for pre/post match footage, as well as video replays
- Player biographies
- Public information (order of play, ''Next match'', security information)
- Hawk-Eye electronic line calls
Although we are able to provide an efficient, cost effective solution, we maintain the high levels of reliability and accuracy that we pride ourselves on across all of our core products.