Abstract: An apparatus and method for redirecting an incident beam makes use of a wobble plate to precess the normal to the mirror surface about a predetermined axis coupled with a rotational movement about the axis of the wobble plate to provide the second degree of freedom needed to place the reflected beam exactly on target.

Abstract: A scanning system for linearized application of an energy beam along at least one of a plurality of predetermined axes. Chopper means intercept the energy beam for alternately reflecting and passing the energy beam providing successive reflective and passed beams respectively therefrom. First and second scanning means receive the reflected and passed beams respectively. The first and second scanning means synchronously direct the reflected and passed beams along at least one of the predetermined axes.

Abstract: A sensing system and method for detecting changes in the level of a liquid surface utilizing a source of essentially monochromatic illumination of narrow beam width for directing an incident beam toward a liquid surface at an oblique angle thereto, and thereby providing a reflected beam therefrom. A beam expander is interposed between the illumination source and the liquid source for increasing the narrow beam width of the incident beam to a beam width substantially greater than the wavelength of disturbances in the liquid surface. A converging lens is mounted transverse to and intercepts a portion of the reflected beam from the liquid surface for focusing that portion of the reflected beam to a centrum. A beam detector is positioned adjacent to the centrum for providing an indication of changes in the level of the liquid surface by detecting corresponding changes in a relative position of the centrum.