Abstract: A plurality of movable objects, such as aircraft, are provided with GPS receivers, enabling the individual determination of longitude and latitude. Further, the receiver also receives a very precise time base from the GPS satellites. This very precise time base is used to enable all of the plurality of movable objects to transmit in a predetermined radio frequency their identities and positions in precisely determined time blocks. By limiting the range of the frequencies used by the movable objects to transmit, the range of receivability is limited, such that the system may be implemented as a worldwide overlapping mosaic. The transmissions of each movable object may be received by all of the plurality of movable objects, as well as by air traffic monitoring centers on the ground.