Automated tennis line calling system

A method for automatically determining whether a ball is in or out of play in a game played on a field of play in which the ball strikes within or without boundaries demarcated by boundary lines, comprising:

• attaching a multiplicity of elongated pressure-sensitive devices located parallel to, and in proximity with the boundary lines, wherein, in response to a change in pressure, each pressure sensitive device produces an electrical pressure signal;
• locating a multiplicity of sound-sensitive devices spaced around the periphery of the field of play, wherein each such device produces an electric sound signal in response to a sound;
• processing the sound signals to produce approximate location information of the ball;
• and
• processing said approximate location information together with said pressure signals to determine a precise location of the ball.

An apparatus for automatically determining the source and the time of occurrence and location of a sound-producing event on a field of play in a ball game, comprising:

• a multiplicity sound-sensitive devices spaced around the periphery of the field of play, wherein each such sound sensitive device produces an electric signal in response to a sound detected in the air;
• and
• means for processing the electrical signals produced by the sound-sensitive devices to determine service and the location and time of occurrence of the sound-producing event;
• whereby the apparatus is able to determine, to a high degree of accuracy, where the ball strikes various objects including the field of play, or whether a ball is in or out of play.

An apparatus for use during tennis play, comprising:

• one or more coaxial cables attached to the net, wherein each cable produces an electrical signal in response to a change of pressure on said cable;
• means for processing the electrical signals produced by the coaxial cables;
• and
• means for providing an indication from said processed signal,
• whereby said indication may be used to determine whether or not the ball has struck the net.