Computer Science – Performance
Scientific paper
May 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992aas...180.0907l&link_type=abstract
American Astronomical Society, 180th AAS Meeting, #09.07; Bulletin of the American Astronomical Society, Vol. 24, p.741
Computer Science
Performance
8
Scientific paper
The program to digitize the second Palomar sky survey (POSS-II) is based on scans done with the same modified PDS microdensitometers that were used for the Guide Star Catalog. An approximately Gaussian aperture with a nominal size of 30 microns\ (FW at e(-2) ) is used with a sampling interval of 15 microns. The full rasters, 23,040 pixels square, occupy 1.06 Gbytes. A number of quality control steps following scanning are used to verify proper electronic performance of the system, as well as the photometric and astrometric integrity of the scans, e.g., extensive visual inspection, bit and pixel statistics, sky modeling, and calibrations against reference objects; representative data from these controls, as well as near-term plans for their enhancement, are presented. The accepted scans, together with supporting files, are archived four times on 8-mm tape, with two of each being sent to separate off-site locations. The selection of an archival optical disk procedure for the scans is also in progress, with actual transfer from the 8-mm tapes to begin within a year. The community distribution, most likely on CD ROM, will use the same low-loss compression techniques already in use (White, Postman, and Lattanzi, in Dig. Opt. Sky Surveys -- II, ed. H. MacGillivray). Samples of such compressed images will be displayed, together with a discussion of their photometric and astrometric properties. With a nominal compression of 15 and present CD storage densities, the collection of J, F, and N plates would be a 300 volume set. The POSS-II is funded by grants to Caltech from the Eastman Kodak Co., the National Geographic Society, the Samuel Oschin Foundation, the NSF grants AST 84-08225 and AST 87-19465, and the NASA grants NGL 05002140 and NAGW 1710. ST ScI is operated by AURA, Inc., under contract to NASA; image compression algorithms at the ST ScI were developed under NASA grant NAGW 2166.
Djorgovski Stanislav
Laidler Victoria G.
Lasker Barry M.
Postman Marc
Reid Iain Neill
No associations
LandOfFree
The Palomar Observatory - ST ScI Digital Sky Survey. II. The Scanning Process. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Palomar Observatory - ST ScI Digital Sky Survey. II. The Scanning Process., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Palomar Observatory - ST ScI Digital Sky Survey. II. The Scanning Process. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1512301