Determining surface profile from sequential interference patterns from a long tracer profiler

The long trace profiler [P. Z. Takacs and S. Qian, U.S. Patent No. 4884697 (5 December, 1989)] is a slope-measuring instrument that was introduced several years ago. Development of this instrument continues at Lawrence Berkeley Laboratory in improving both hardware design and software algorithms for turning the raw interference data (a sequence of intensity patterns) into properly interpreted representations of surface slope and height. This report presents a mathematical model of the interference pattern and methods of extracting the slope and height profile from such patterns.