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about $300,000 per year beginning in 1983, it will be
possible to establish and operate archives at most major
U.S. observatories by the end of the decade.
V I I . ASTRONOMICAL DATA BASES
By astronomical data bases we mean collections of machine-
readable tabular data such as star catalogs, tables of
opacities, bibliographic data, and indices to observa-
tional data. We draw a distinction between data bases
and archives containing processed observations because
the differences in data volumes and types imply differ-
ences in storage volumes and access rates. A star catalog
may contain entries for several hundred thousand stars and
may have a much higher scientific information content than
a digital image. However, the bit content of such a cata-
log is equaled by that of only a few digital images.
Users of a digital image generally require access to the
whole image (or at least a substantial fraction of the
image). Users of tabular data typically need data for
only a small number of entries.
Because the volume and access rates of tabular data
are small, it is feasible with present-day technology, at
modest expense, to (1) store these data bases in a few
central locations, (2) generate cross-reference tables
linking several catalogs, (3) make the data bases avail-
able on a rapid access on-line medium, and (4) provide
remote user access to data bases via inexpensive dial-up
lines. Activities along these lines, especially for items
(1) and (2), are already under way at a number of loca-
tions including Strasbourg, France, and NASA/Goddard
Space Flight Center, Greenbelt, Maryland.
We believe that these collections of computer-readable
astronomical data bases constitute an essential library
resource for the astronomical community and that this
resource is underutilized at present. We recommend that
the data-base activities be continued and expanded and
that implementation of remote access dial-in ports be
implemented as soon as possible. As data archives are
implemented (see the preceding section), copies of the
indices of the archives should be maintained in the
centralized tabular data bases. This will facilitate
unified searches for all observations of a particular
object or region of the sky. The construction of
bibliographic data bases will be facilitated if journal
editors require that each author submit with his or her
Representative terms from entire chapter:
tabular data
