Communication and navigation system using satellites uses correlation of signals from telephone satellites to determine global position

摘要

the system uses satellites for dual purposes. The communication and navigation system uses a number of satellites in low or medium orbit, with the same satellites offering both services. The mobile telephones are able to calculate their position with the aid of receivers capable of correlating the signals from two satellites during a period of not more than a few seconds, and pref. in a fraction of a second. One of the two satellites must be able to respond to interrogation by the mobile to determine universal time. The mobile is then able to determine its position from this satellite by deduction from the time and its distance from the satellite.