Instead, the tournament uses Hawk-Eye Live, an electronic line-calling system, to determine whether a tennis shot is in or out.
Electronic line-calling has been around tennis since the 1980s, dating back to Cyclops, a system used during Wimbledon to judge if a ball was in play or not.
"During that match, the U.S. Open was trialing a Hawk-Eye system," said Clarey.
After the match, Williams received an apology and the umpire was dismissed.
"The NBA have chosen Sony and Hawk-Eye technology because it raises the level of their game," said Theresa Alesso, president of Imaging Products and Solutions Americas at Sony.
Persons:
Christopher Clarey, Roger Federer, Paul Hawkins, it's, Serena Williams, Jennifer Capriati, Williams, Ben Figueiredo, Figueiredo, Craig O'Shannessy, Novak Djokovic, We've, Theresa Alesso
Organizations:
U.S ., New York Times, International Tennis Federation, Australian, U.S, Sony, WNBA, MLS, NFL, NBA, Imaging Products, Solutions
Locations:
Wimbledon, U.S