Ground monitoring schemes for GPS integrity channel

Issues involved in the design and implementation of the ground monitor segment Global Positioning System (GPS) are analyzed. In particular, two alternative ground monitoring schemes are presented and compared, one using classified GPS information, and the other not. For each scheme, processing functions that must be performed by the ground monitoring segment are identified, considering both the impact of selective availability on monitoring and the integrity decision concept recommended by the Global Integrity Channel (GIC) Working Group of the Radio Technical Commission for Aeronautics Special Committee-159