Method, apparatus and system for estimating user position with a satellite positioning system in poor signal conditions Patent #: 6473694
ApplicationNo. 10/300501 filed on 11/19/2002
US Classes:342/357.02, With accuracy enhancing342/357.06, Using Global Positioning Satellite (GPS or Glonass)342/357.1, Combined with telecommunication701/214Means to improve accuracy of position or location
ExaminersPrimary: Blum, Theodore M.
International ClassG01S 1/00 (20060101)
AbstractA navigation satellite receiver method determines what navData is on-hand, what level of time uncertainty exists, and what position uncertainty there is for the receiver at turn-on. Indoor and outdoor search engines are used that can vary their search windows and dwell times to increase receiver sensitivity. Received signals are stored in several playback loops that can be operated in parallel to increase search sensitivity in the face of large uncertainties in time ad frequency, and still reduce the time-to-first-fix. Satellite acquisition can be achieved even when the navData is too weak to be read by requesting help from a server.