Honeywell has posted some very interesting videos on its website explaining how its new satellite-based landing system, SmartPath, works. SmartPath is a ground-based augmentation system (GBAS), and is expected to be certified by the FAA this year -- the first of this type to be approved in the U.S.
The FAA plans to eventually use GBAS systems to replace (or complement) traditional ILS systems at airports. GBAS has many benefits over ILS, not the least of which is cost. A single GBAS unit can cover up to 26 approaches, whereas a separate ILS is needed at the end of every runway.
Screen grab from GBAS video
The videos can be seen here. One of them provides an animation of how GBAS works on approach and departure. Another shows an interesting history of the development of ILS systems, and how this will evolve through satellite-based navigation.