Lenticular Sheet Generated Optical Patterns for Aircraft Navigation

Under proper conditions, lenticular sheets can §generate visual patterns which are usable as a §navigational aid. A distant observer can use this §navigational aid to precisely determine its relative §position. §§The navigational aid is constructed by mounting a §lenticular sheet over a pattern of periodically §spaced lines sharing the sheet's period. This §configuration results in the appearance of lines §perpendicular to the original pattern,§which are visible to a distant observer. The §apparent location of these lines depends on the §position of the observer relative to the §navigational aid, and exhibit a linear dependance on §observer displacement along a single dimension. Two §mutually orthogonal lenticular sheets lying on a §single plane will provide the observer with §sufficient visual information to determine its §position within its respective plane. The apparent §size of the navigational aid can be used to infer §relative displacement normal to this plane, allowing §the observer to ascertain its position in three §dimensions from a single image.§§This navigational aid is analyzed theoretically and §demonstrated with a working prototype.