Archivo: Signal Mirror Glass USAF MIL-M-18371E Type II

Descripción: Per the dodimagery.afis.osd.mil website, where this photo was found: "A combat control team member, TSGT Richard Heins, uses a signal mirror to signal an approaching C-141 Starlifter aircraft that is transporting paratroopers into a drop zone. The airman is a 317th Tactical Air Wing member participating in exercise Reforger '80." The mirror is a standard issue MilSpec MIL-M-18371E Type II 3"x5" glass mirror. The MilSpec can be found here: http://www.tpub.com/content/MIL-SPEC/MIL-M/MIL-M-18371E/ Per section 3.2 of that spec, the mirror uses two layers of 1/8" glass laminated with polyvinyl butyral, with a sighting device of 30x30 stainless steel mesh coated on both sides with wide-angle retroreflective material, and the back and all the edges painted flat black. The way this type of mirror is aimed is that the aiming mesh creates a glowing "fireball" virtual image of the sun, visible only to someone looking through the rear of the aimer. The reflected light from the mirror is in the same direction as the apparent direction of the "fireball", so the user simply tilts the mirror to place the "fireball" on the target. This type of aimer was patented in 1951 by Richard S. Hunter, US Patent 2,557,108, which can be viewed here: http://www.google.com/patents?id=y35vAAAAEBAJ
Título: Signal Mirror Glass USAF MIL-M-18371E Type II
Créditos: US Government Web Site: http://dodimagery.afis.osd.mil/assetDetails.action?guid=177ced942f14b527fd0f7f79608101dd92ea81eb image name DF-ST-82-03772.JPEG
Autor(a): Photographer: TSGT Bob Wickley, USAF, editor C. Tordesillas
Términos de Uso: Dominio Público
Licencia: Dominio Público
¿Se exige la atribución?: No