Time determination in satellite positioning system receivers and methods therefor

US6944540B2 · kind B2 · utility

Assignee

• Motorola, Inc. · US

Inventors

• Thomas M. King · Tempe, US
• George J. Geier · Scottsdale, US
• Rodney P. Landers · Woodbury, US
• Michael J. Slade · Libertyville, US
• Paul Declerck · Palatine, US

Key dates

• Filing date: Mar 28, 2002
• Grant date: Sep 13, 2005
• Expiry date: Apr 14, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S2205/008
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method in a Global Positioning System (GPS) receivers, including determining pseudorange (PNR) measurements for at least four satellites (210), determining a coarse time (220) corresponding to the pseudorange measurement, determining an offset time (240) between a periodic GPS event of one of the four satellites and the coarse time, determining a time correction delta (250) based upon the period of the Periodic GPS event, the offset time and the coarse time if an error of the coarse time is less than ½ the period of the periodic GPS event, and determining corrected time (260) based upon the coarse time and the time correction delta if the error of the coarse time is less than ½ the period of the periodic GPS event.