For several years now a number of companies have been developing and testing train localisation systems which include GPS as a positioning element. In some cases, the systems were developed for Automatic Train Protection/Control (ATP/ATC) operations and thus needed to meet the stringent requirements typical of railway safety-of-life applications ([1]). On the opposite side, other implemented systems have been devoted to the provision of actual timetable information and consisted of little more than a mere GPS receiver connected to a communication device which reported the actual location of the train to a central control station ([2]). This paper describes a novel GPS-based train localisation system currently under development in Socratec. This system, code-named SATURN, can be considered as a "middle way" between the two classes of systems previously mentioned and focuses on applications where safety-of-life issues are not critical but reliable operation and high accuracy may be necessary (e.g. low traffic rail lines and shunting stations).
展开▼
