METHOD AND SYSTEM FOR NAVIGATION USING GPS VELOCITY VECTOR

摘要

A navigation device includes a computer platform that includes a global positioning system (GPS) receiver operable to acquire and track a GPS signal, a processor assembly, and a memory. The memory includes at least one of last recorded Ephemeris and Almanac information, and a GPS velocity vector determination module operable to generate a velocity vector output in the absence of current Ephemeris based upon the tracked GPS signal and the last recorded GPS information. A method of vehicle navigation in the absence of current Ephemeris includes acquiring and tracking a GPS signal, retrieving from a memory a last recorded location of a vehicle, setting a dead reckoning startup location equal to the last recorded location, retrieving from a memory at least one of a last recorded Ephemeris and Almanac, determining a current velocity vector and determining a current location based upon the velocity vector and the dead reckoning startup location.