Railway vehicle detection

A method of detecting a railway vehicle, comprising sending a only one initial pulse from the vehicle to a first point and a second point at a single time and location, determining the time difference between receiving at the first and second points the signal pulse and using that time difference to produce an indication of that location of the vehicle through navigational triangulation, said first and second points being spaced from the vehicle and separate from each other.

A system for detection of a railway vehicle, comprising means for using the time difference between reception at first and second points of only one signal pulse initially sent from the vehicle to the first and second points at a given time, and a reference clock wherein the time difference is measured against the reference clock, wherein said first and second points are spaced from the vehicle and separate from each other so that, through navigational triangulation an indication of the location of the vehicle results.

A method of detecting a railway vehicle, comprising using the time difference between receiving at first and second points a signal sent from the vehicle at a given time to produce an indication of the location of the vehicle, including the step of measuring the time difference against a reference clock.