Two or more objects, or an object and an environment are each fitted with two or more range measurement devices. Each of the range measurement devices is provided with a transceiver capable of outputting a unique code and information that can be used in range measurement, and receiving from other range measurement devices unique codes and information that can be used in range measurement. Range measurements from range measurement devices on the object or located in the environment are used to derive the relative position of the range measurement devices, from which a relative position of the objects, or of the object and an environment can be derived.