Patent ID: 8159397

Claim:
A system for enhancing position determination by a rover, the system comprising: A. one or more base stations in known locations, each base station including one or more receivers for receiving and processing return two way time transfer (TWTT) signals from one or more rovers and determining information relating to position and clock differences for the respective rovers based on the time travel of the return TWTT signals, and one or both of a phase offset of a code in the return TWTT signals and timing information included in the return TWTT signals, and a transmitter for transmitting one or more TWTT signals, the transmitter further transmitting information related to one or both of the locations of and the timing at the respective one or more rovers; B. the one or more rovers, each rover including one or more receivers for receiving the TWTT signals and the information transmitted by the one or more base stations, processing the information transmitted by the one or more base stations and determining position, timing or both, and a transmitter for transmitting to the one or more base stations the return TWTT signals that are in response to the receipt of TWTT signals transmitted by the one or more base stations.