Accession Number : ADA280949


Title :   The 3.5-Meter Telescope Enclosure


Descriptive Note : Final rept. 17 Aug 1991-31 Mar 1993


Corporate Author : PHILLIPS LAB KIRTLAND AFB NM


Personal Author(s) : Brady, Michael H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a280949.pdf


Report Date : Apr 1994


Pagination or Media Count : 26


Abstract : The 3.5-m telescope enclosure is designed to perform two functions as part of the U.S. Air Force's 3.5-m telescope system: (1) to provide weather and temperature protection when the telescope is not in use and (2) to permit open- air operation of the telescope while minimizing atmospheric disturbances in the field of view (FOV). The use of a standard rotating dome is impractical because of the large telescope and its high rotational rate and acceleration. The enclosure is a 40-ft tall cylinder with a diameter of 72 ft. This steel and aluminum structure does not rotate but collapses vertically to fully expose the telescope to the open air and to provide it with an unobscured view of the horizon at all azimuthal angles. To lessen wind disturbances in the FOV, the enclosure has a moderately sloped roof and smooth, vertical walls. To minimize thermal flow, the outer surface has a high-reflectivity, low-emissivity coating and ambient air is forced through the double-skinned walls and roof. These measures make it possible to keep the enclosure surface temperature near that of the ambient air during viewing. With these features, the enclosure adds minimal degradation to the seeing.


Descriptors :   *TELESCOPES , OPTICAL EQUIPMENT , TEMPERATURE , STRUCTURES , WIND , OPTICAL INSTRUMENTS , FABRICATION , ATMOSPHERIC DISTURBANCES , REFLECTIVITY , DOMES(STRUCTURAL FORMS)


Subject Categories : Optical Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE