Patent ID: 7415353
Filing Date: 2008-08-19
Classification: G01S

Abstract:
1. A method of operating a navigation receiver, comprising: whenever a navigation receiver has ephemeris information unavailable to it directly from orbiting navigation satellites because of weak signal conditions, then: accepting a partial-ephemeris in a satellite-position table message from a network host that lacks at least one of the two harmonic corrections to inclination angle, Cic and Cis, of the flight trajectory of a particular orbiting navigation satellite, wherein said network host has stripped out such data from a complete almanac collected by a reference station at another location; computing a position solution using said reduced ephemeris information from said satellite-position table message; and outputting said position solution with an accuracy degraded due to having omitted either of said two harmonic corrections to inclination angle, Cic and Cis, in the step of computing.