This paper proposes an algorithm for an optical measuring system, which is capable of calculating the velocity and position components, the radius and the trajectory of a flying sphere-shape ball. The infrared light-emitting diodes and the IR sensors of the system are arranged in a single plane and create a lattice of infrared light beams. The FPGA based hardware of the system measures the points in time when the light beams are interrupted by the ball. The proposed algorithm uses the measured time-data with the associated positions of the interrupted light beams as input. The practical application such a systems can be measuring ball's velocity in several sports and games. © Springer International Publishing Switzerland 2014.