摘要 |
Positioning apparatus for use in a moving vehicle includes circuitry arranged to process signals received from GPS satellites, and to provide signals in response thereto from which the position of the apparatus can be calculated at a remote station. The apparatus provides, for each satellite in view, carrier frequency estimation signals, samples of the carrier signals and code tracking signals to a data transmission device, which modulates the signals onto a carrier prior to transmission to the remote station. A carrier loop reconstruction device and a location processor in the remote station cooperate to determine the location of the positioning apparatus. A memory device at the remote station may record the signals received from the vehicle over a period of time, for subsequent carrier loop reconstruction and location determination.
|