A golf game employing r.f-tag coded golf balls has a playing area with r.f. antennae located underneath to enable the number of strokes taken by a player to be counted. Separate antennae are provided for the tee area and hole, respectively, and the antennae around the hole are smaller to improve resolution....http://www.google.com.hk/patents/US7040998?utm_source=gb-gplus-share專利 US7040998 - Golf putting game with means for automatically monitoring the movement of the ball
