SBAS

• SBAS Satellites


  Stationary in Space
• GBAS


  GPS Receivers on the Ground at Base Stations that Track and Transmit Corrections to the on-coming receivers on Aircrafts or Roving GPS Receivers from, common epochs received from satellites in Space
• Augmentation


  Increases, expands, intensify the level of precision from the GPS signals and Improves the quality and the Integrity of the Point Positioning
• SBAS


  Satellite Based Augmentation System/s
• SBAS and GBAS share the same basic principle - they provide supplementary information whose objective is to Improving the quality of GPS/GNSS signal performance and/or the trustworthiness and integrity of GPS positioning
• Forms of Augmentation systems

  • RIMS (Ranging and Integrity Monitor Stations)
  • Wide Area Augmentation System (WAAS)
  • EGNOS
  • Quazi Zenith/MSAS
  • New satellite system (SBAS) Australian and NZ GPS users

  
• QZSS


  Provides additional overhead ranging sources in the Asia & Japan area as an augmentation service to GPS
• GAGAN


  GPS and GEO Augmented Navigation to cover the Indian subcontinent is the Indian own SBAS program

  
• How SBAS/GBAS systems work


  1. RIMS stations receive GPS, GLONASS and GALILEO signals

  2. Position of RIMS stations known precisely

  3. Data from RIMS sent to Central Processing Centre

  4. Central Processing Centre calculates long term satellite orbit errors, short and long term satellite clock errors, ionosphere correction grids, and integrity information

  5. Integrity information used to inform users within 6 seconds of GPS system problems
• Under ideal conditions a WAAS equipped GPS receiver can achieve three meter accuracy 95% of the time
• Under ideal conditions, a GPS receiver without WAAS can achieve fifteen meter accuracy most of the time
• DGPS


  Differential GPS on Real Time Kinematic (RTK) or Post Processing, needs a Base Receiver to transmit corrections, very long baseline need L1/L2 frequencies
• SBAS/GBAS


  Receivers have access to the Ionospheric Grid, corrections come from all SBAS signals in Space, no additional long-wave receiver is necessary to receive the correction data and there is no need for an endless number of DGPS beacons that transmit these correction data