IAU Working Group Densification of Optical Reference Frames
last update: 2009 May 08, Norbert Zacharias
1. Ground-based photographic, wide-field surveys and catalogs
=============================================================
Early epoch surveys are still important for astrometry due to the large
leverage arm for determining accurate proper motions in combination with
more recent observations.
These surveys are based on digitized, photographic plates.
-----------------------------------------------------------------------------
project epoch pos.err. mag sky literature comments
name year mas range area reference explanation
-----------------------------------------------------------------------------
AC 1890-1930 200 4-13 all [01,02] Astrographic Catalogue
AGK2 1930-1932 70 5-12 north [03,04] part of UCAC3 release
NPM 1947-1987 100 5-18 north [05,06] Northern Proper Motions
SPM 1965-2008 40-150 5-18 south [07-09] Southern Proper Motions
USNO-B 1949-2002 200-300 12-21 all [10] Schmidt plates
GSC-2.3 1949-2002 300 12-21 all [11] Schmidt plates
SuperCOSMOS 1949-2002 250 12-21 all [12-14] Schmidt plates
NOMAD ... ... 0-21 all [15] merged dataset
LQAC ... ... 13-21 all [16] only quasars
-----------------------------------------------------------------------------
AC Astrographic Catalogue plates were obtained with "normal astrographs"
(60 arcsec/mm scale) at about 20 observatories around the world. Most
plates were taken around 1900 on blue sensitive emulsion. All plates
were measured manually over decades. The recent reductions on the
Hipparcos Catalogue system are based on key-punched data of those
manual measures, not on modern plate scans. An excellent history is
given in [02] while the modern results are presented in [01].
AGK2 is the second Astronomische Gesellschaft Katalog, based on over 1900
blue sensitive, fine grain emulsion plates taken at the Hamburg and
Bonn observatories, Germany. The original catalog contains 186,000
stars which were manually measured, together with the AGK3 repeat
observations about 30 years later. The data used for the UCAC3 is
based on StarScan [04] measures completed at the U.S.Naval Observatory
and reduced to the Hipparcos System. Accurate positions of over
1 million stars were obtained for the -2.5 to +90 deg sky area.
This will significantly improve the proper motions for stars to
about B=11 (mostly Tycho-2 stars) in the northern hemisphere.
NPM and SPM are dedicated, astrometric programs using 50 cm aperture,
wide-field astrographs (Lick, CA, and Yale/San Juan, Argentina),
to derive absolute proper motions of stars with respect to galaxies,
utilizing data taken at 2 epochs about 20 to 30 years apart.
USNO-B, GSC-2.3, and SuperCOSMOS are programs to measure and reduce
the various northern and southern deep Schmidt plates. Different
measure machines and reduction techniques have been used by the
3 groups. All astrometric results are based on the Tycho-2
reference stars and suffer from overexposure effects of these
bright stars as seen on the deep Schmidt plates.
NOMAD, the Navel Observatory Merged Astrometric Dataset is based on
Hipparcos, Tycho-2, UCAC2, "Yellow sky" (unpublished scans of
part of the NPM and SPM collections performed by D.Monet at the
PMM in Flagstaff), and the USNO-B1 catalogs, picking "the best"
astrometry from among the input catalogs (no compiled data).
NOMAD is supplemented by 2MASS photometry.
LQAC contains over 100,000 confirmed quasars (all-sky) and features the
best available positions based on radio and optical observations
with cross-references to various catalogs.
[01] Urban, S.E. et al. (1998),
The AC 2000.2 Catalogue, AJ 115, 1212,
also CDS VizieR on-line catalog I/275 (2001)
[02] Eichhorn, H. (1974),
Astronomy of Star Positions, Frederick Ungar Publ. Co., New York
[03] Dieckvoss, W. (1960),
Progress on the AGK3, AJ 65, 171
[04] Zacharias, N., Winter, L, Holdenried, E.R. et al (2008)
The StarScan plate measuring machine: overview and calibrations,
PASP, 120, 644 (astro-ph 0806.0256)
[05] Klemola, A.R., Jones, B.F., Hanson, R.B. (1987),
Lick Northern Proper Motion program, AJ 94, 501
[06] Hanson, R.B., Klemola, A.R., Jones, B.F., Monet, D.G. (2004),
Lick Northern Proper Motion Program III, AJ 128, 1430
[07] Girard, T.M., Platais, I., Kozhurina-Platais, V., van Altena, W.F. (1998),
The Southern Proper Motion Program I, AJ 115, 2556
[08] Platais, I., Girard, T.M., Kozhurina-Platais, V. et al. (1998),
The Southern Proper Motion Program II, AJ 116, 2556
[09] Girard, T.M., Dinescu, D.I., van Altena, W.F. et al. (1998).
The Yale/San Juan Southern Proper Motion Catalog 3, ASP Conf.317, 206
[10] Monet, D.G., Levine, S.E., Canzian, B. et al. (2003),
The USNO-B Catalog, AJ 125, 984
[11] Bucciarelli, B., Lattanzi, M.G., McLean, B. et al. (2008),
The GSC-II catalog release GSC 2.3: description and properties,
in proceed. IAU Symp.248, p.316, Cambridge Univ.Press
Eds. W.Jin, I.Platais, M.A.C.Perryman
[12] Hambly, N.C., MacGillivray, H.T., Read, M.A. et al. (2001),
The SuperCOSMOS Sky Survey - I. Introduction and description
MNRAS 326, 1279
[13] Hambly, N.C., Irwin, M.J., MacGillivray, H.T. (2001),
The SuperCOSMOS Sky Survey - II. Image detection, parametrization,
classification and photometry, MNRAS 326, 1295
[14] Hambly, N.C., Davenhall, A.C., Irwin, M.J., MacGillivray, H.T. (2001),
The SuperCOSMOS Sky Survey - III. Astrometry, MNRAS 326, 1315
[15] Zacharias, N., Monet, D.G., Levine, S.E. et al. (2004),
The Naval Observatory Merged Astrometric Dataset (NOMAD),
AAS Bull. 36, 1418
[16] Souchay, et al. (2008),
The Large Quasar Astrometric Catalogue,
ftp://syrte.obspm.fr/pub/LQAC