Current research in robotic vision is focused mainly on the recognition of two dimensional patterns. In many applications, however, depth perception capability is an essential feature. In principle, depth perception can be deduced from stereoscopic vision or from holographic reconstruction, but the algorithm required to interpret the information is extremely complicated and requires substantial computation. This research proposes the development of a much simpler method of ranging based on the observation that the relative position of the peaks of a diffraction pattern due to a point source observed through a grating are found to shift as the distance between the point source and grating is changed. This phenomena has been observed at visual frequencies and should be scalable to microwave frequencies. Using millimeter waves, an instrument should have a range of sensitivity from about 1 to 1000 meters. The proposed research sill carry out detailed experiments at optical and microwave frequencies as a basis for developing such a ranging instrument.
