This Sky Survey is extremely rare; it is a condensed version of the 102 disc sky survey that was put out in 1994 by the Palomar Observatory costing $3,500 to order.
The Palomar Observatory Sky Survey
The National Geographic Society's Palomar Observatory Sky Survey project was a seven year effort to construct a photographic atlas of the sky using the 48-inch Oschin Schmidt Telescope on Palomar Mountain. Completed in 1958, this project produced thousands of 14 inch square glass plates, each of which encompassed a 6.4 degree square area (with about a 0.4 degree overlap between plates). Photographed in two wavelength ranges (red and blue), nebulas and stars down to about magnitude 20 were recorded. Copy sets of the survey (printed on paper and less frequently on glass) became a basic research tool for astronomers everywhere because of the enormous amount of information that they contained.
The Digitized Sky Survey
The Space Telescope Science Institute digitized the Palomar Observatory Sky Survey as part of an intensive eight year effort to prepare the Guide Star Catalog (GSC) for the Hubble Space Telescope. It took five years to accurately scan the plates and convert them into a database. The resulting digitized scans represented a huge quantity of data, with each plate scan measuring 14,000 X 14,000 16 bit pixels; thus, astronomers from the Space Telescope Science Institute compressed the data by a ratio of ten to one (using an algorithm to minimize information loss) to make it more accessible to researchers. In 1994, the compressed data, dubbed the Digitized Sky Survey, was released to researchers on 102 CD-ROM's.
RealSky: Providing Access for Everyone
In cooperation with both the Space Telescope Science Institute and the Astronomical Society of the Pacific, a compressed version of the Digitized Sky Survey data, appropriately named RealSky. This set of nine CD-ROM's (eight for data and one for software) contains the E band (red) plates from the Palomar Observatory Sky Survey, compressed by a factor of 100, and it also contains RealSkyView — a software package that you can use to display and process the images. For the first time, everyone has access to the actual deep-sky survey plates used by research astronomers!
RealSkyView Software
RealSkyView gives you the power to view and manipulate the RealSky images on both Windows and Macintosh platforms. With RealSkyView, you can display the RealSky images on your computer screen, smooth or sharpen the images, rotate the images, alter the brightness and contrast of the images, quickly set up browse lists for examining the images, and more.