Analysis of the M113 Panoramic Telescope Radioactively Illuminated Reticle,
DECILOG INC MELVILLE N Y
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Historically, reticles in optical instruments were illuminated by a battery powered incandescent source for use at night. The source luminance was controlled by means of a potentiometer, and was equipped with an OnOff switch. Thus, as evening twilight approached, and the dark lines became difficult to see against the scene, the reticle light was turned on. Initially, high reticle illumination would be used, and, as the scene became increasingly dark, the reticle would be dimmed. When tritium activated sources of illumination became availabel, it became feasible to eliminate the battery and incandescent source with a concomitant savings in cost and increase in reliability. In the M113 Pantel, for example, the reticle is constantly illuminated by the radioactive source. Therefore, there exists a time at twilight when the reticle cannot be seen as either dark lines or lighted lines. This report defines the problem, presents some short term solutions to the problem, and suggests an experimental program designed to create a reticle design data base and handbook.
- Optical Detection and Detectors