Method and apparatus for improving accuracy and/or integrity of long-term-orbit information for a global-navigation-satellite system

摘要

A method and apparatus for monitoring a configuration of satellites to maintain integrity of LTO information in a GNSS receiver of a GNSS or other positioning system is described. The method comprises truncating the LTO information as a function of time so as to form truncated LTO information with a reduced period of validity. The method may include obtaining broadcast ephemeris transmitted from at least one satellite of a constellation of satellites; comparing the broadcast ephemeris to long-term-orbit information available to a global-navigation-satellite receiver; and causing the global-navigation-satellite receiver to not use the long-term-orbit information when the long-term-orbit information does not correspond to the broadcast ephemeris.