SuperCOSMOS

SuperCOSMOS is the Royal Observatory Edinburgh's advanced photographic plate digitising facility. It succeeds the COSMOS machine which was in operation at the ROE until December 1993. SuperCOSMOS is 10 times more powerful than COSMOS.

The essential components of SuperCOSMOS consist of a granite air-bearing xy table providing high accuracy precision measurements, a linear CCD array (of 2048 pixels) providing the high-speed scanning capability and transputers and DEC Alpha workstations for rapid data processing. The entire system is housed in an environmental chamber, providing class 100 clean-room conditions and strict thermal stability (temperature maintained to +/- 0.05 degrees Centigrade over a 24 hour period) thus ensuring strict integrity during the scan process.

Glass plates up to 20" x 20" in size and films up to 14" x 14" can be accepted for scanning. The photographic material is digitised to 15 bits with a resolution of 10 microns. The central 320mm x 320mm area of a Schmidt plate is digitised in a timescale of 2 hours, producing some 2 GBytes of pixel data. These data are currently processed using the COSMOS crowded-field analysis software (Beard et al. 1990, MNRAS, 247, 311) producing a catalogue of all the objects detected above the detection threshold, with some 32 parameters stored for each image (Image Analysis Mode - IAM - data). Transformation of x,y to RA,Dec is performed through cross-referencing with the PPM catalogue. Resulting celestial coordinates are output in the FK5 system with equinox J2000 adopted as standard.

Users can receive the raw pixel data for their plates, or solely the IAM data or both. Data transport is usually in the form of exabyte or DAT tape in TAR or FITS format.

The facility is available for routine scanning of users' plates on request. However, the sky survey material from the major sky surveys (POSS in the North, UKST and ESO in the South) is being systematically digitised at the 10 micron resolution. While the raw pixel data for these surveys are being routinely archived and will in time be made available generally, the main drive of the facility is to provide multi-colour and multi-epoch Object Catalogues of the Southern and Northern skies. These catalogues will be distributed and made available for network access in the same way as the COSMOS/UKST catalogue of the Southern sky.

Anyone requiring further information on the SuperCOSMOS facility should contact:-

Dr H. T. MacGillivray
Royal Observatory
Blackford Hill
Edinburgh, EH9 3HJ
Scotland, U.K.

E-mail: hmg@roe.ac.uk