Cylindrical Holograms for Target Recognition Training.
Abstract
Techniques were developed for constructing cylindrically shaped holograms to be used to train the recognition of various military targets. In the past, a set of photographs was used to teach the target identification. Each photograph presented a different angular viewpoint of the target. The cylindrical format holograms provided a significant improvement over the previous methods by presenting a continuous view of the target through 360 degree rotations. A infinite number of aspect views were effectively presented. A unique vacuum film holder was constructed to support the film in a stationary manner during exposure without distorting the flexible film. The gaussian power shape of the laser beam was used to compensate the 1/r square beam intensity falloff through the length of the film cylinder. The laser beams was circularly polarized to eliminate TE and TM polarization reflection differences around the cylindrically shaped film in accordance with the Fresnel equations. The resulting holograms were evaluated in terms of the proposed application to target recognition training. Alternate film configurations were proposed and experimentally evaluated. (AUthor)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1977
- Accession Number
- ADA042430
Entities
People
- Neil Mohon