Is there an optimum height to place the infrared sensors?
Yes, the height of the infrared sensor plane-of-rotation should match the height of the beacon LEDs. This will give you the maximum sensitivity and, more importantly, allow you to design an infrared sensor housing that will limit the view of the sensors to only include the plane the beacon LEDs are radiating in. This will help prevent beacon reflection problems from below (e.g., the diamond plate sprinkled around the field) and above. Additional information about beacon reflection problems can be found below.