Astronomical archives and databases: a WWW-accessible example

F.Pasian, R.Smareglia
Osservatorio Astronomico
Trieste, Italy

Currently-existing archives and databases in astronomy, although being of great scientific interest, lack a truly distributed client-server architecture, and are therefore sometimes awkward to use. Those using commercial DBMS's need to export software at the user's site, and thus have licence and software distribution problems, or their usability is limited to a small number of computer platforms. Furthermore, the approaches to data access and distribution are often completely different. In this paper, an astronomical archive containing 2-D (images) and 1-D (spectra) data is described, with particular reference to its user interface, based on NCSA/Mosaic and allowing it to be accessible through World-Wide-Web. The architecture allows database browsing by specifying query constraints inside forms to be filled by the user, display of 1-D and 2-D quick-look data, graphical visualization of numerical results derived from a query, retrieval of observational data from the data bank. All of the information on the user interface is dynamically stored in the database (handled by an SQL-based relational DBMS), allowing the Mosaic screens to be prepared on-the-fly; no additional software needs to be run on the user's computer.