Patent Document ID: 20100039320
Application ID: 12192057
Patent Flag: 0

Claim One:
1. A method for use in locating a mobile device, comprising: (a) at the mobile device, obtaining 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); (b) computing 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; (c) obtaining an uplink time difference of arrival (U-TDOA) measurement representing a first baseline between first and second terrestrial receivers; (d) providing hybrid GPS/U-TDOA baselines; (e) computing weightings for the hybrid GPS/U-TDOA baselines; and (f) estimating the location of the mobile device using the hybrid GPS/U-TDOA baselines and the weightings.