Using of 2 cameras on the tennis court with 480x270 resolution (32 bits colour) at 25 frame rate. With the purpose of obtaining 3d trajectory of the ball that allows making an estimation with approximately 7 ms of error of the moment of touching of the ball with the ground. Also, it is necessary to give an approximation of the position of the bounce but the error in the estimation can be around 10 cm of error.
Form the input of the two cameras, a C++/python/C# algorithm (we prefer C++ for a fast algorithm) can estimate the 3D trajectory of the ball and detect the ball bouncing taking into consideration illumination changes of outdoor scenes. The camera is a global shutter type, and the exposure time of the cameras can be controlled and the position of the camera can vary by the action of the wind, etc.