Electronic football linesman

Abstract

An electronic system using RF Transmitters, Receivers, Transponders and a Computer are used to measure location and distance. Using a unique method, this system measures the delay between direct and echoed RF signals from different aspects to convert RF propagation delay into triangulated distance information. It is configured to act as a measuring tool for the linesman in the game of football. It is used to spot the ball (determine location), determine if a first down has been achieved (measure/calculate change in location) and aid the linesman in centering the ball on the playfield and assess penalties(give a constant location reading). Unlike radio direction finding methods of locating a football, it has no moving parts and is completely cordless.

1 ) What I claim as my invention is a method of determining location and distance on a football field by using a differential measurement of the propagation delay of an electro-magnetic wave from a transmitter placed next to the ball. This method is described by the set-up, calibration and operation steps as follows: 
 a) Set-up the system by placing the repeater units at the corners of the playing field and the Master Receiver/Master Logic Unit on the sidelines.    b) Calibrate the system by placing the transmitter Wand at one corner of the playing field and transmitting an RF burst. Receiving the directly transmitted burst at the Master Receiver/Logic Unit. Measuring the difference in time until the echoed burst from each of the Repeaters arrives at the Master Receiver/Master Logic Unit. Repeating this differential measurement as the Wand is moved to the other corners of the playing field.    c) Using the measured maximum and minimum differential propagation delay, corresponding to farthest and nearest distance the Wand will be from each of the Repeaters, create a mathematical algorithm to translate this differential propagation delay into positioning on the field in yards.    d) Operating the system during the football game by placing the Wand next to the ball and sending out an RF burst, which is then used to determine the location of the football on the field.    
     
     
         2 ) Using the method of determining the position of the football on the playing field as described in  claim 1 , determine dynamic and statistical data about the game including but not limited to: 
 a) Yards to go for a first down    b) Total offense yards    c) Total yards of penalties    
     
     
         3 ) Using the method as described in  claim 1 , send out a continuous stream of RF bursts from the Wand to give constant position information of the Wand for the purpose of: 
 a) Repositioning the ball on the playing field    b) Assessing penalties