TABLE OF CONTENTS In Chapters 4 and 5 large sections were devoted to air applications of satellite navigation systems and the related benefits. Therefore, this chapter is mainly devoted to other applications related to the L/W and S layers. However, it is useful for the sake of completeness to summarize the major achievements and perspectives related to the A layer.
A GNSS can be used for air navigation in three basic roles:
As a primary navigation system, hence able to meet all requirements to use certain procedures or to fly in certain airspace without the need for any other navigation system onboard the aircraft. The primary system may include one or more integrated navigation sensors (e.g., GPS with an inertial reference system) [76, 81 86].
As a supplemental system that can be used alone without comparison to another system: however, a primary system that could be used in the event that the supplemental system is not available must be onboard the aircraft.
As a multisensor navigation system that can be used for navigation but only after it has been compared for integrity with a primary system of the aircraft.
When the operational capability of a civil GPS signal arrived in the late 1980s, the civil community within the United States quickly embraced the technology and adopted minimum operational performance standards (MOPS) and TSO for commercial and general aviation (GA) aircraft [35, 87]. It is worth mentioning that the GA term describes all aviation except government...
