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).

Survey Name

Survey Code

Epoch of observations

Photographic Emulsion +filter

Band Name

Approximate limiting Magnitude

Declination zone / coverage

Number of plates

DSS pixel size in arcsec

GSC version

DSS version

DSS Copyright holder

POSS-I E

XE

1950-58

103aE

Epg

20.0

+90:-30

936

1.0/1.7"

2

1

STScI

POSS-I O

XO

1950-58

103aO

Opg

21.0

+90:-30

936

1.0"

2

2

STScI

Pal-QV

N

1983-85

IIaD
+W12

Vpg

19.5

+90:+06

611

1.7"

1+2

2

STScI

POSS-II J

XJ

1987-98

IIIaJ
+GG395

Jpg

22.5

+90:+00

897

1.0"

2

2

Caltech

POSS-II F

XP

1987-98

IIIaF
+RG610

Fpg

20.8

+90:+00

897

1.0"

2

2

Caltech

POSS-II N

XI

1987-02

IV-N
+RG9

Ipg

19.5

+90:+00

890

1.0"

2

2

Caltech

SERC-J

S

1975-87

IIIaJ
+GG395

Jpg

23.0

-20:-90

606

1.7"

1+2

1

ROE

SERC-EJ

S

1979-88

IIIaJ
+GG395

Jpg

23.0

-00:-15

288

1.7"

1+2

1

ROE

AAO-SES

XS

1990-98

IIIaF
+OG590

Fpg

22.0

-20:-90

606

1.0"

2

2

AAO

SERC-ER

ER

1984-98

IIIaF
+OG590

Fpg

22.0

-00:-15

288

1.0"

2

2

AAO/ROE

AAO-SR

GR

1996-99

IIIaF
+OG590

Fpg

14.0

Southern galactic plane

116

1.0"

2

2

AAO

SERC-I

IS

1990-02

IV-N
+RG715

Ipg

19.5

-00:-90

894

1.0"

2

2

AAO

SERC-QV

XV

1986-88

IIaD
+GG495

Vpg

14.0

Southern galactic plane

94

1.0/1.7"

1+2

1

ROE

SERC-V
& PAL-V

XX

1979-85

IIIaJ
+GG495

Vpg

variable

M31,  LMC, SMC

4

1.7"

1+2

1

STScI/ROE

DSS Data Access

The Digitized Sky Survey images are available on-line from a number of data archives around the world as well as built-in to astronomical data viewers such as Aladin, Worldwide Telescope and Google Sky. The data may be retrieved directly from STScI/MAST using the links and/or API's described below:

Get image cutout (FITS or GIF format)https://archive.stsci.edu/cgi-bin/dss_form

DSS Image Access : http://archive.stsci.edu/cgi-bin/dss_search?Parameters

Required Parameter List

  • R=ra(hh:mm:ss.s)
  • D=dec(dd:mm:ss.s)
  • V= phase2_gsc1 | phase2_gsc2 | poss2ukstu | poss2ukstu_red | poss2ukstu_blue | poss2ukstu_ir | dss1 | poss1_red | poss1_blue | quickv
  • H=height (arcmin)
  • W=width (arcmin)

Optional Parameters

  • F=fits (default)| gif
  • C=none (default) | unix | gzip
  • FOV= none (default) | launch | sm93 | sm97
  • V3=roll angle (deg)

e.g.

Identify available plates to cutouthttps://archive.stsci.edu/cgi-bin/dss_plate_finder

DSS Plate Finder : http://archive.stsci.edu/cgi-bin/dss_plate_finder?Parameters

Required Parameter List

  • R=ra(hh:mm:ss.s)
  • D=dec(dd:mm:ss.s)
  • H=height (arcmin)
  • W=width (arcmin)

Optional Parameters

  • FORMAT= FITS(default) | GIF
  • PLATE_ID=xxxx DSS plate ID
  • ACTION=EXTRACT

e.g.

Get image cutout (color JPG)none

DSS JPG Image Access : http://gsss.stsci.edu/webservices/dssjpg/dss.svc/GetImage?Parameters

Required Parameter List

  • POS=ra(deg),dec(deg)
  • SIZE=width(deg),height(deg) | diameter(deg)

Optional Parameters

  • ISIZE= WIDTH,HEIGHT | WIDTH | 0 in pixels optional size of resulting image
  • ZOOM = 1|2|4|8|16|32|64|DYNAMIC zoom level of image returned
  • DRAWDEBUG= ON|OFF to display tile outlines

e.g.

  • No labels

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Send comments & corrections on this MAST document to: archive@stsci.edu.