Integrity enhancement of the GNSS position solution for the railway applications

Increasing progress in the field of the satellite navigation systems (GNSS, SBAS) in recent decades supports the effort to use it for the determination of train position for the railway safety-related systems. Satellite-based augmentation systems (SBAS) such as WAAS in the USA, and EGNOS in Europe, are available and new global satellite navigation system Galileo is being built in Europe. Currently available SBAS systems were developed in order to satisfy the aviation requirements, but the safety concept on the railways is very different from the aviation safety concept. New method for increasing integrity of GNSS position solution at the earth ground is described. Properties of this method are experimentally examined by simulations of errors in pseudoranges.