The use of GNSS in navigation, timing and related systems for transportation is ever increasing. The railways are no exception. There are various programmes underway looking at the application of GNSS to the railway for safety-critical functions. Significant among these is train location and control. Traditional line-side signalling is expensive through installation, operation and maintenance. It is inflexible; signalling headways and hence capacity are determined by physical location of signals, track circuits and associated infrastructure, and it is vulnerable; signalling cables and apparatus are frequently stolen by metal thieves – it’s scrap value being very high. Read More