text: Sports simulation systems designed to simulate sports experiences are well known in the art. In many conventional sports simulation systems, a player propels a sports projectile such as a ball, puck, arrow, dart, etc. at a target image presented on a display screen. The motion of the sports projectile is detected and imaged and an extrapolation of the trajectory of the sports projectile is made. The extrapolated trajectory is then used to determine a sports result. The displayed image is in turn updated to reflect the sports result thereby to provide the player with visual feedback and simulate a sports experience.
  The goal of all sports simulation systems is to provide the player with a realistic sports experience. As a result, many variations of sports simulation systems have been considered in attempts to simulate accurately “real-life” sports experiences. For example, U.S. Pat. No. 5,333,874 to Arnold et al. discloses a sports simulator having a housing and two arrays of infrared (IR) receivers and emitters positioned in the housing. A launch area is established near one end of the housing. A user can launch an object such as a golf ball located in the launch area and drive the golf ball into the housing through the planes defined by the arrays of IR emitters and against a screen positioned at one end of the housing. A computer is connected to the IR receivers, which detect the passage of the object through the respective planes. Based upon the signals from the IR receivers, the computer uses triangulation techniques to determine the horizontal and vertical position, as well as the velocity of the golf ball. The computer can also determine the spin of the golf ball and cause an image of the golf ball as it would have appeared traveling away from the golfer had it not encountered the screen to be displayed on the screen.
  U.S. Pat. No. 5,443,260 to Stewart et al. discloses a baseball training and amusement apparatus that detects the speed and projected flight of a batted baseball. The apparatus includes a ball delivery device, a pair of detection planes, a computer and a video and simulation monitor. The detection planes are parallel to one another and are spaced apart by a distance such that a batted ball passing through the detection planes would be a fair ball in a real baseball game. Each detection plane includes a rigid frame that supports a pair of optical scanners and a pair of light sources. The optical scanners and light sources are positioned at opposite top corners of the rigid frame and are aimed downwardly into the region encompassed by the frame.
  During use, the ball delivery apparatus delivers a baseball towards a player positioned in front of the detection planes. When the player strikes the baseball with a bat and the baseball travels through the detection planes, the optical scanners capture images of the baseball. The images are processed to determine the coordinates of the baseball as it passes through each of the detection planes as well as the velocity of the baseball. A simulated trajectory of the baseball is then calculated using the determined coordinate and velocity information. The simulated trajectory information is used to update the graphical images presented on the monitor so that the simulated flight of the batted baseball is displayed to the player thereby to simulate a batting experience.
  U.S. Pat. No. 5,649,706 to Treat, Jr. et al. discloses a hunting simulator for in-flight detection of a launched missile such as an arrow. The hunting simulator includes a screen and a projector for projecting a moving target on the screen. Electromagnetic radiation emitters are positioned in front of the screen adjacent its opposite top corners and illuminate a plane in front of the screen. Sensors are also positioned adjacent the opposite top corners of the screen and are responsive to the electromagnetic radiation emitters. Retroreflective tape extends along opposite sides of the plane.
  During use, when an arrow is launched at the screen and passes through the plane, the sensors detect the presence of the arrow and generate output. The output of the sensors is used to determine the coordinates of the arrow as well as the velocity of the arrow. A simulated trajectory of the arrow is then calculated and the graphical images presented on the screen are updated accordingly to reflect the flight of the launched arrow. In this manner, a hunting experience is simulated.
  U.S. Pat. No. 5,768,151 to Lowy et al. discloses a system for determining the trajectory of an object in a sports simulator. The system includes a baseball throwing device to deliver a baseball towards a player area. A projector adjacent the player area presents images on a display screen that is positioned near the ball throwing device and in front of a batter. Video cameras are positioned in front of and on opposite sides of the anticipated trajectory of a hit baseball.
  During use when a baseball delivered by the ball throwing device is hit by the batter and passes through the fields of the view of the video cameras, images of the baseball are captured and a streak showing the path of the baseball through the fields of view is determined. The streak is used to simulate the flight of the baseball and to update the image presented on the display screen thereby to simulate a batting experience.
  Although the above references disclose sports simulation systems that capture images of launched projectiles and use the image data to simulate the flight of the launched projectiles, these sports simulation systems fail to provide “true to life” sports experiences as a result of the mechanisms used to track the path of the launched projectiles.
  Above-incorporated U.S. Patent Application Publication No. US2006/0063574 to Richardson et al. discloses a sports simulation system comprising a projectile tracking apparatus having a display surface on which a three-dimensional sports scene is presented. The projectile tracking apparatus captures images of a projectile tracking region disposed in front of the display surface to detect a launched projectile traveling through the projectile tracking region towards the display surface. At least one processing stage communicates with the projectile tracking apparatus and is responsive to the data received from the projectile tracking apparatus to determine the three-dimensional positions, velocity, acceleration and spin of a detected projectile traveling through the projectile tracking region. The determined three-dimensional positions, velocity, acceleration and spin are used by the at least one processing stage to calculate a trajectory of the launched projectile into the three-dimensional sports scene. Updated image data is generated by the at least one processing stage that includes a simulation of the launched projectile into the three-dimensional sports scene following the calculated trajectory. A projection unit coupled to the at least one processing stage receives the image data from the at least one processing stage and presents the three-dimensional sports scene, including the simulation, on the display surface.
  Although this sports simulation system provides a better and more realistic sports experience, in certain environments such as for example, during club fitting, teaching and swing analysis, more accurate simulations are desired. It is therefore an object of the present invention to provide a novel sports simulation system and a novel projectile tracking apparatus.