摘要 |
Methods and systems are disclosed for radio positioning of a mobile receiver using a virtual positioning reference established by logging a known position of the mobile receiver together with a local time at which a first instance of a predictably repeated code word is received by the mobile receiver from a terrestrial radio signal transmitter. During movement of the mobile receiver from the first known position to a second unknown position, a local clock is used to determine the time difference between when the virtual positioning reference is predicted to receive a second instance of the code word and when the mobile receiver actually receives the second instance of the code word. |