PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = " 2014-10-15 SBN:Blankenship Initial version 2015-04-16 SBN:T.Barnes formatting edits and added REFERENCE_KEY_ID" OBJECT = INSTRUMENT INSTRUMENT_HOST_ID = "BGONDOLA" INSTRUMENT_ID = "BIRC" OBJECT = INSTRUMENT_INFORMATION INSTRUMENT_NAME = "BRRISON INFRARED CAMERA" INSTRUMENT_TYPE = "IMAGING CAMERA" INSTRUMENT_DESC = " The BRRISON Infrared Camera (BIRC) is a multispectral imager designed to measure water and carbon dioxide emissions from cometary comae. BIRC has 8 narrow band filters in the infrared, from about 2.5 to 5 microns, and a single broadband filter in the R band centered about 640.7 nm. BIRC consists of a detector, filter wheel, cryostat, and integrated relay optics. The BIRC is mounted on one of the two optical benches behind the main 0.8 meter telescope. The BIRC sits on the distal optical bench, while the UVVis instrument sits on the proximal optical bench. The main telescope is flight heritage technology and was used in the Stratospheric Terahertz Observatory (STO). The main telescope is an on-axis cassegrain with a diameter of 0.8 m and f/17.5. The main telescope brings the light to a prime focus at the UVVis optical bench. A two-position mirror mounted on the UVVis optical bench determines whether the light stays in the UVVis Bench or is allowed to pass through a hole and continue to the IR optical bench. When the light enters the IR optical bench it encounters three fold mirrors and an aspheric mirror that collimate the light prior to entering a 50.3 mm, f/4 Ritchey-Chretien (mini-RC) telescope. The mini-RC is mounted within the cryostat and vacuum system of the BIRC camera. The filter wheel holds a total of 9 filters. 8 of these are narrow band near-IR filters. The ninth filter is an R-band filter and primarily used for lab testing and calibration. To minimize the time spent moving the filter, the filters commonly used together are placed near each other. The filter positions are listed below along with their wavelength. BIRC uses a Teledyne H2RG 2048 x 2048 HgCdTe array with a 5.1 micron cutoff at 77 K. Only a portion of the full array is used; the illuminated field of view is ~155 pixels in diameter corresponding to ~3 arcmin across. A single pixel is ~1.16 arcsec across. The integration time of the camera is set in 3.45 ms increments with a minimum of 3.45 ms. It is necessary to operate BIRC near liquid nitrogen temperature in order to reduce the background emission from the instrument itself. BIRC is divided into multiple zones for cooling. The structure containing the camera focal plane, called the 'inner sanctum', is operated at ~70 K. The mini-RC telescope, attached to the inner sanctum, operates at ~80 K. The filter wheel is kept in the same vacuum chamber as the inner sanctum but is cooled separately with liquid nitrogen to ~125 K. The 3 folding mirrors and the collimating aspheric mirror are kept in a separate enclosure operated at ~190 K and cooled with liquid nitrogen. The main telescope and optical bench operate at or above ambient temperature. BIRC Vital Statistics Main telescope aperture 80 cm Main telescope F-number f/17.5 Mini-RC telescope aperture 50.3 mm Mini-RC telescope F-number f/4 Field-of-view 3 arcmin Pixel field-of-view 1.16 arcsec Spectral channels 9 Detector type Teledyne H2RG HgCdTe array Pixels per image 2048 x 2048 BIRC Camera Filters Wavelength FWHM Position R band* Unspecified 1 2.47 3% 6 2.73 3% 5 2.85 3% 9 3.05 3% 8 3.20 3% 7 4.00 3% 3 4.27 3% 4 4.60 3% 2 * This filter is centered about 640.7 nm " END_OBJECT = INSTRUMENT_INFORMATION OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "N/A" END_OBJECT = INSTRUMENT_REFERENCE_INFO END_OBJECT = INSTRUMENT END