Implementation of the normative safety case structure for satellite based railway applications

Enabling safe, green and intelligent railway transportation is a major target of transportation research. This is supported by satellite based localisation systems (GNSS) like GPS which already provide large economical and operational benefits by supporting applications in transport like passenger information, energy saving driving or tracking and tracing. The application of satellite based localisation systems for information purposes is a valuated contribution for a more efficient operation of trains. If satellite based localisation can be used as mean of safe localisation in train control systems, higher benefits according a safer and more reliable operation can be expected. To enable the usage in this application field, the certification of the localisation unit according the valid normative background of railways is necessary. Traditionally, a development of a product in railways starts with requirements which are the base for the product development and the following certification process. For the approval of an application of satellite based localisation for safety relevant purposes in railways, an already existing system like GPS shall be used as localisation device and therefore as important data source and needs therefore to be included into the certification process because of no generic certification of GLASS being already available. This paper can be the base for an approval process enabling the certification of satellite based localisation in railways.