Abstract: Provided is a navigation system for operating a navigation system, which navigation system includes a first sub navigation system placed at an aeroplane and a second stationary sub system, which first sub navigation system includes a plurality of radio receivers, which radio receivers are configured to receive signal from a plurality of navigation satellites, which navigation system includes at least one processor, which processor is configured to perform calculation of the actual position data, which navigation system includes a radio transmitter, which radio transmitter is configured to transmit position data to communication satellites. The communication satellites can include radio transmitters for transmitting position data to a ground based receiver, which second sub system includes at least one server. Hereby can position data in that way the position of that aeroplane will be calculated and the actual position data and actual time will be stored in the server.