DIRA2

DIRA2 (Distributed Information Retrieval system for Astronomical file)
is a software structure that allows the astronomer to manage in a
simple and articulate way the  astronomical data files, especially
catalogues. The users can access this structure by a set of
commands that activate specific procedures.

DIRA2 allows the creation and the management of a catalogue data base,
either of general or private use (master and personal data base
respectively). The manipulation of files, the extraction of subfiles by
user defined criteria, and the iconographic view of the results are
supported by the command set.

DIRA2 mainly performs the management of data files containing
catalogues. The main actions are: the creation of the data base, the
updating, the query and data retrieval and the graphic representation
of the output. The DIRA2 commands act on catalogues either on disk or
tape. The catalogues can be in a public area, or in a private directory.
Users can write catalogues, or select data from existing ones
and manage them with the DIRA2 commands.

DIRA2 is able to:

-- Provide the user with all the system available specifications:
   catalogue file location, names, reading formats, entry codes
   in the catalogue record. One can also obtain astronomical
   documentation of the catalogue content.

-- Create, manage, search, query and retrieve data from the Data Base.

-- Create a new catalogue field as a function of existing fields, or
   create new catalogues as a junction of existing catalogues.

-- Transform the astronomical coordinate system of the catalogues.

-- Supply the user with some user-oriented utilities for the data
   display and graphic search. One can get maps, wedge diagrams,
   histograms, regressions on graphic devices or workstations catalogue
   data can be retrieved by cursor location.

-- Write and read catalogues and tables in FITS format.

-- Provide the user with means to develop his own programs of data
   base use, by calling a library of FORTRAN subroutines.

The main feature of the DIRA2 philosophy is that the catalogues and the
variables, (e.g. Right Ascension, Declination, Magnitude etc\dots ) are
known to the system by conventional codes defined in a vocabulary. This
means, in practice, that if one is interested on a list of magnitudes
from the Uppsala General Catalogue, he needs to enter the keywords "UGC"
and "MAG", besides, of course,  other minor specifications on output

About 280 catalogues are presently available in DIRA2. The users
can insert other catalogues with a minimal effort. All the commands provide
default values and have an help structure.

DIRA2 is available at the computers of I.R.A.: 
                and on all the Alpha and Linux workstations.
		
On these computer you can start DIRA2 typing, at the user prompt,:  dira2 

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or you can access Dira2-WWW to :http://db.ira.inaf.it/dira2

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Manual is available at I.R.A. library.

Contact people:

		M.Nanni      nanni@ira.inaf.it
                F.Tinarelli  tinarelli@ira.inaf.it