THREE LEVELS OF ACCURACY

• Differential GPS with OnPath or OmniSTAR® correction

  The vehicle with a GPS antenna receives signals from the GPS satellite constellation. The OnPath or OmniSTAR® services, which have a number of ground based GPS receivers spread across the area for which they deliver a correction, receive the same GPS messages as the vehicle. They are able to calculate the real time position error and send this as a message to control stations, which then upload the message to a geostationary satellite. The geostationary satellite receives the correction message, and re-transmits it back to the receiver on the vehicle.
  
  

  	Pass-to-Pass	Year-to-Year
  OnPath	+/- 30cm	+/- 90 cm
  OmniSTAR® XP*	+/- 15 cm	+/- 25 cm
  OmniSTAR® HP*	+/- 10 cm	+/- 25 cm

  
  New Holland cannot guarantee performance and availability of OnPath and OmniSTAR® services. *OmniSTAR® correction requires subscription to OmniSTAR® service.
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  RTK (Real Time Kinematic)

  This is a highly precise technology that results in 2.5 cm year-to-year accuracy. This accuracy can be achieved with two communication technologies, depending upon your needs in terms of working area coverage:
  
  

  	Pass-to-Pass	Year-to-Year
  RTK	+/- 2.5 cm	+/- 2.5 cm

  
  RTK uses a local ground based station which receives the same position data as the mobile unit.
• By comparing the received position to its known actual position, the real time error can be calculated. This error is then transmitted via short wave radio to the mobile unit. By combining GPS and Glonass constellation input, accuracy can be further improved. Radio repeaters can be positioned to fill in any areas of signal loss from the base station. Signal loss could be caused by rugged terrain or thick vegetation.