Photographic Sky Surveys

This table summarizes the photographic survey plates used in the construction of GSC-1 and GSC-2. The northern sky was observed using the Palomar observatory 48" Samuel Oschin telescope, whilst the southern sky was observed using the UK Schmidt telescope at the Anglo-Australian Observatory. These photographic glass plates were then digitized by STScI and processed to create the Guide Star Catalogs. The initial set of scans only included a single plate for each region of the sky and were published as the Digitized Sky Survey (DSS-1) and processed into GSC-1 to support HST operations. After the initial release, a DSS consortium  came together to both obtain additional second epoch plates, digitize at a higher resolution and process them into DSS-2/GSC-2. Whilst there are exceptions, the bulk of the sky has observations in at least 3 bandpasses (blue, red and near-IR).