The Sloan Digital Sky Survey will perform a five color imaging survey of (pi) steradians of the Northern sky to a depth of m_r approximately equals 23 and obtain the redshifts of 10⁶ galaxies and 10⁵ quasars. The survey will be performed on a specialized 2.5 m telescope equipped with a 30 CCD imaging camera and a 4 CCD dual beam fiber spectrograph for spectroscopy. It is expected to take five years to complete. A five color image of a quarter of the night sky with seeing limited resolution is unprecedented. So is the volume of data to be obtained and archived, approximately 10 TBytes. The data rates of approximately 10 Mbytes/sec have precedence only in high energy physics. (Hence the involvement of Fermilab in the survey.) Such a large and unique dataset deserves and demands an excellent calibration. We have taken as a goal 1% photometry. In normal astronomical projects, one could expect to spend up to half the program time on calibrations to obtain this precision. In project of the scale of the Sloan Digital Sky Survey, the cost of this is prohibitive. We have decided to pursue an alternative approach involving a separate telescope to supply calibrations for the survey data and monitor the photometric conditions of the atmosphere.

Date Published: 1 June 1994
PDF: 8 pages
Proc. SPIE 2198, Instrumentation in Astronomy VIII, (1 June 1994); doi: 10.1117/12.176741

Published in SPIE Proceedings Vol. 2198:
Instrumentation in Astronomy VIII
David L. Crawford; Eric R. Craine, Editor(s)