A tracking system for tracking a position and orientation of an object (122, 411, 511, 1011), the tracking system including: a) a tracking base (121, 450, 550, 1050) provided in an environment, the tracking base including i) a tracking head support ( 452, 552, 1052); and, ii) at least three tracking heads (121; 451.1, 451.2, 451.3; 551.1, 551.2, 551.3; 1051.1, 1051.2, 1051.3) mounted to the tracking head support, each tracking head having: a radiation source arranged to send a radiation beam to a respective target; a base sensor that senses reflected radiation; at least one tracking head actuator (854, 857) that controls an orientation of the tracking head; and, at least one tracking head angle sensor (855, 858) that monitors an orientation of the tracking head; b) a target system (460, 560, 1060) including at least three targets (461.1, 461.2, 461.3; 561.1, 561.2, 561.3; 1061.1, 1061.2, 1061.3) mounted to the object (122, 411, 511, 1011); each target including a reflector that reflects the radiation beam to the base sensor of a respective tracking head; and, c) a control system (130, 230, 830), configured in such a way that it: i) causes each tracking head to track a respective target as it moves throughout the environment; ii) determines a position of each target with respect to a respective tracking head at least in part using signals from: each base sensor; and, the at least one tracking head angle sensor; iii) determines an orientation of the target system using at least in part the determined position of each target; and, iv) determines the position and orientation of the object using at least in part the position and orientation of the target system. a) a tracking base (121, 450, 550, 1050) provided in an environment, the tracking base including i) a tracking head support ( 452, 552, 1052); and, ii) at least three tracking heads (121; 451.1, 451.2, 451.3; 551.1, 551.2, 551.3; 1051.1, 1051.2, 1051.3) mounted to the tracking head support, each tracking head having: a radiation source arranged to send a radiation beam to a respective target; a base sensor that senses reflected radiation; at least one tracking head actuator (854, 857) that controls an orientation of the tracking head; and, at least one tracking head angle sensor (855, 858) that monitors an orientation of the tracking head; i) a tracking head support ( 452, 552, 1052); and, ii) at least three tracking heads (121; 451.1, 451.2, 451.3; 551.1, 551.2, 551.3; 1051.1, 1051.2, 1051.3) mounted to the tracking head support, each tracking head having: a radiation source arranged to send a radiation beam to a respective target; a base sensor that senses reflected radiation; at least one tracking head actuator (854, 857) that controls an orientation of the tracking head; and, at least one tracking head angle sensor (855, 858) that monitors an orientation of the tracking head; a radiation source arranged to send a radiation beam to a respective target; a base sensor that senses reflected radiation; at least one tracking head actuator (854, 857) that controls an orientation of the tracking head; and, at least one tracking head angle sensor (855, 858) that monitors an orientation of the tracking head; b) a target system (460, 560, 1060) including at least three targets (461.1, 461.2, 461.3; 561.1, 561.2, 561.3; 1061.1, 1061.2, 1061.3) mounted to the object (122, 411, 511, 1011); each target including a reflector that reflects the radiation beam to the base sensor of a respective tracking head; and, c) a control system (130, 230, 830), configured in such a way that it: i) causes each tracking head to track a respective target as it moves throughout the environment; ii) determines a position of each target with respect to a respective tracking head at least in part using signals from: each base sensor; and, the at least one tracking head angle sensor; iii) determines an orientation of the target system using at least in part the determined position of each target; and, iv) determines the position and orientation of the object using at least in part the position and orientation of the target system. i) causes each tracking head to track a respective target as it moves throughout the environment; ii) determines a position of each target with respect to a respective tracking head at least in part using signals from: each base sensor; and, the at least one tracking head angle sensor; each base sensor; and, the at least one tracking head angle sensor; iii) determines an orientation of the target system using at least in part the determined position of each target; and, iv) determines the position and orientation of the object using at least in part the position and orientation of the target system.