Patent ID: 7755774

Claim:
A system for measuring the displacement of a portion of a railroad track relative to a wheel and rail contact point, the system comprising: a rail vehicle having a body comprising a substantially horizontal frame, and a set of wheels, one of the wheels of the set of wheels engaging the rail at the wheel and rail contact point; first and second optical emitters emitting first and second optical beams, the first and second optical emitters being mounted to the frame at an acute angle relative to the substantially horizontal frame of the body in spaced and opposed relation to each other such that the beams of the first and second optical emitters are converging as the beams are emitted from the first and second optical emitters, the first and second optical beams being detectable on an underlying surface and separated by a distance thereon; and a digital vision system mounted to the vehicle body for recording the first and second optical beams as they reflect from the underlying surface for measuring the vertical displacement of the track at a distance along the rail spaced from at least one of the wheel and rail contact points.