A system for monitoring the movement of objects, structures, models of structures, cables and the like provides for the acquisition of images with an optical sensing device such as a video camera fixedly mounted at a selected distance from the item studied, in which the images are arranged into frames divided into pixels which are characterized by an intensity reflected or emitted over a selected time interval, and a data processing system to calculate a physical displacement as function of time of the item being studied or a portion of the item being studied based on an output from the video camera, and in some embodiments the system visually distinguishes one or more locations in the frame to indicate a difference in the phase of motion for multiple objects appearing in the frame.
