Survey Wavelengths and Sky Coverage
DSS images have one-arsecond pixels and use three broad-band filters covering roughly 3950 Å to 9000 Å. SDSS has smaller pixels (0.39 arcsec) and uses narrower filters in five bands between 3551 Å and 8931 Å. 2MASS has 1 arcsecond pixels and used three near-infrared bands between 1.24 and 2.16 μm.
DSS and 2MASS are all-sky. SDSS DR7 covers 11663 square degrees, mostly in the north galactic polar region. For more information, see below.
|
DSS
The photographic plates scanned for the Digitized
Sky Surve y were taken through relatively wide spectral filters.
None of the underlying datasets are all-sky; the DSS "surveys"
are actually composites of multiple image sets taken at different
times using different instruments. For more detailed information
on filters, dates, and coverage, see
https://gsss.stsci.edu/SkySurveys/SkySurveys.htm Users should be aware that there is some overlap here. For instance, SE RC-J (which covers much of the southern hemisphere) is used in both the compo site surveys GSC1 and DSS2B. |
|
||||||||||||||||||
| SDSS The Sloan Digital Sky Survey will map in detail one-quarters of the sky (concentrating on the north polar cap). Data Release 7 (DR7) covers 11663 square degrees . |
|
||||||||||||||||||
| 2MASS The Two Micron All-Sky Survey covers the whole sky in three near-infrared bands. |
|