a television profile of major sections free of road and rail tunnels made by luminous device to light coherent (laser) rotating on the axis orthogonal plan roadwith subsequent return to scale of the profile itself

摘要

The inside profile of the road or rail tunnel, in accordance with a given cross-section, is shown by the light projected onto the extrados by a laser beam rotating on an x-y plane in relation to the axis of the tunnel at that point. The said luminous profile is framed in its entirety by a fixed television camera placed at a fixed distance from the plane on which the laser beam rotates, which generates it and then recorded by a normal video recorder. Both the light source and the TV camera are fixed to the same vehicle and for this reason the television survey of the said luminous profiles can be carried out even while the vehicle is moving. Afterwards the measurements are taken directly on the said profiles plotted to scale on paper or on the digitalised video image by means of computerised graphics techniques.