Patents Represented by Attorney, Agent or Law Firm Chan Park
  • Patent number: 6278404
    Abstract: The satellite selection method as utilized by the spaceborne Global Positioning System receiver provides navigational solutions and is designed for use in low Earth orbit. The satellite selection method is a robust algorithm that can be used a GPS receiver to select appropriate GPS satellites for use in calculating point solutions or attitude solutions. The method is takes into account the difficulty of finding a particular GPS satellite phase code, especially when the search range in greatly increased due to Doppler shifts introduced into the carrier frequency. The method starts with an update of the antenna pointing and spacecraft vectors to determine the antenna backplane direction. Next, the GPS satellites that will potentially be in view of the antenna are ranked on a list, whereby the list is generated based on the estimated attitude and position of each GPS satellite. Satellites blocked by the Earth are not entered on this list.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: August 21, 2001
    Assignee: The United States of America as represented by the United States National Aeronautics and Space Administration
    Inventor: Frederick A. Niles