Patent ID: 8199050

Claim:
A method for use in locating a mobile device, wherein the mobile device is configured to obtain pseudorange measurements based on signals received from one or more satellites, wherein said one or more satellites are satellites of at least one of a Global Navigation Satellite System (GNSS) or Global Positioning System (GPS), and to compute GPS time difference of arrival (G-TDOA) values based on the GPS pseudorange measurements, said G-TDOA values representing baselines between the mobile device and the GPS/GNSS satellites, comprising: obtaining an uplink time difference of arrival (U-TDOA) measurement representing a first baseline between first and second terrestrial receivers; providing hybrid GPS/U-TDOA baselines; computing weightings for the hybrid GPS/U-TDOA baselines; and estimating the location of the mobile device using the hybrid GPS/U-TDOA baselines and the weightings.