Satellite-based Augmentation Systems

SBAS is a navigation support system that creates differential correction information for error sources and enables this information to be transmitted to aircraft within the coverage area via ground fixed (GEO) orbiting satellites that act as transmitters. SBAS provides navigation support to users at all flight stages (departure, en-route, approach and landing). It enables CAT-I-like approach and landing procedures at the final approach and landing stages.

ADVANTAGES:

• Wide Coverage Area
  Coverage in SBAS systems by broadcasting correction information via satellites
  it reaches a much wider range of coverage than existing navigation aids.
• Low Maintenance and Maintenance Costs
  There is no need for ground section installation for the SBAS system at airports. Therefore, maintenance and maintenance costs are lower.
• Use in All Flight Phases
  Possibility to use in all flight phases including en-route approach and landing phase
  are available.
• Flexible Approach and Landing Routes
  Apart from the direct approach (straight-in approaches), it also enables flexible and non-linear approaches 
• Efficiency and Cost
  It offers the most cost-effective solution within the scope of increasing flight capacity and efficiency and minimizing environmental impacts within the concept of Event Field Navigation (RNAV) and Performance Based Navigation (PBN).
• Working Independently of Environmental Conditions
  Environmental constraints included in existing approach and landing procedures with SBAS systems (eg:
  temperature restrictions, adverse weather conditions, snow, etc.) related requirements are eliminated.
• Wide range of use
  SBAS systems are used in many areas other than aviation (maritime, construction, road and rail transport,
  military applications, etc.).
  Many have their own SBAS system.

USA: Wide Area Augmentation System (WAAS)
JAPAN: Multi-functional Satellite Augmentation System (MSAS)
INDIA: GPS and GEO Augmented Navigation (GAGAN)
CHINA: Satellite Navigation Augmentation System (SNAS) (in development)

SOUTH KOREA: Wide Area Differential Global Positioning System (WADGPS) (in
development)
RUSSIA: System for Differential Corrections and Monitoring (SDCM) (in development).