Variable pitch grating for Diffraction Range Finding, U.S. Patent #6,490,028
A means for overcoming perspective foreshortening in the receiver of a diffraction range finder by use of chirp diffraction grating 121. In a diffraction range finder, a diffraction grating with variations in pitch such that the displacement of higher-order diffraction images in a receiver are separated from their associated zero-order image by an arbitrary displacement with respect to an arbitrary target distance. A system for ranging a target comprising a variable pitch grating 122 and a receiver 200 of the diffraction images formed by said grating.
DeWitt, Thomas D. and Lyon, Douglas A., "Variable pitch grating for Diffraction Range Finding, U.S. Patent #6,490,028" (1996). Engineering Faculty Publications. 77.
Thomas D. DeWitt and Douglas A. Lyons. “Variable pitch grating for Diffraction Range Finding”, US PPA 60/034,112, issued as US Patent #6,490,028, European Patent Number 97 955 059.7 and Canadian Patent Number 2277211, December 30, 1996.