Camera Design

THE BIGGEST MONOLITHIC CCD CAMERA IN THE WORLD

The OMI will employ the largest single sensor chip (monolithic) CCD in the world. It measures 95.22 mm x 95.22 mm and has about 112 million pixels. We wanted a single chip camera rather than a mosaic (combination of smaller chips) for several reasons. First off monolithic CCD's are significantly more cost effective than mosaics per unit area. Second monolithic CCD's have no gaps unlike mosaics than can have hundreds of pixels in the gaps. Third monolithic CCD's are much more reliable because they have fewer interconnections.

CCD image courtesy of Spectral Instruments Inc.

ARCHITECTURE

The chip, STA1600A, is made by Semiconductor Technology Association (STA) and was first fabricated on 21 June 2006 at DALSA Semiconductor. It was specifically designed for the USNO (United States Naval Observatory) for astrometry. Each pixel measures 9 microns square and the array has 16 ports for rapid reading. The chip features a 100% fill factor. Internally it is configured as a split frame transfer of 10580 x 5280, each having 8 read ports. The chip will be back illuminated and thinned with enhanced UV coatings.

The camera will be manufactured by Spectral Instruments Inc.

PERFORMANCE

• 10580 x 10560 ~ 111.5 mega-pixel prime focus camera (world's biggest monolithic CCD chip)
• 95.22mm x 95.22mm active area with 100% fill factor
• 0.76 arc-sec pixels (9u pixel width)
• ~16 seconds readout time full array at 1 MHz
• ~1.6 seconds at 10MHz (rn = 18e-)
• 3.5 frames/sec at f = 25MHz (rn = 40e-)
• 16 readout ports
• CTE = 0.999999
• Linearity ~1%
• SNR = 78 dB at 1 MHz, 65 dB at 25 MHz
• Typical defects 3 columns, 99.9993% good pixels
• Gbit fiber interface
• >90% QE in r
• Readout noise <4e- at 1MHz
• Readout noise 18e- at 10MHz
• ­100ºC cryo-cooled
• Dark current 1e-/pix/hr
• 16 bit quantization
• Full well capacity of 80,000 e-
• Summing register depth of 500,000 e-
• 300-1000nm back illuminated (thinned) with enhanced UV
• 223,449,600 bytes per image (16 bits active pixels)
• 670,348,800 bytes per tricolor image

FILTERS

These are the same filter sets used by CFHT, SLOAN, Gemini and Pan-STARRS.

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