Measurement of deformation of large structures - scanned by laser beam at successive times with reference comparison

摘要

The method is for measuring movements or deformations of large structures using laser beams which are deflected over a definite area of the surface of the object at separate times, the reflected beams being received at the observing station and compared with a predetermined reference point reflection to determine any change which has taken place during the interval between the two measurements. The defined area may be specified by a paint spot or other suitable identification. The system is independent of the size of the structure and its distance from the observer, and permits accuracies of fractions of a millimeter in three coordinates.