Overview of INES (version 3.0)

Basic Concept

INES (IUE Newly-Extracted Spectra) is the processing and distribution system for the archive of more than 110000 spectra of some 9600 objects observed over the lifetime of IUE. The distribution system utilizes a distributed architecture which comprises the Principal Centre, located at LAEFF in Villafranca, Spain and mirrored at CADC in Canada, and a series of National Hosts around the world. In the client-server framework of the system, the client queries the archive access catalogue and requests data, and the server responds. In this context the Principal Centre, its Mirror and the National Hosts are servers, and the end-user is the client. Access catalogue queries and data requests are resolved by the National Host server, but data requests for high resolution spectra and SILO files are passed transparently to the Principal Centre server or its mirror. Client-server communication is via the HTTP protocol and Common Gateway Interface programs.


The INES distribution system provides the following functionality to the end-user:

Archive Searches

An access catalogue query is made by means of a fill-in form, and permits query by object name, coordinates, object type, observing date, instrumental parameters and image or object list. Four output fields can be selected, and each may be output in HTML, ASCII or as tab- or comma-separated values. The output fields may be ordered by date and time of the observation, coordinates, camera and image number, IUE object class and object name. The system allows to select between the Principal Centre and the Mirror site. An on-line description of each archive search-keyword is available via links embedded in the query form.

Data Products

In addition to the access and publications' catalogues and the project documentation, each National Host server stores the newly extracted low resolution spectra (with improved extraction, new noise models and a homogenized wavelength scale), and high resolution, concatenated spectra rebinned onto the low resolution wavelength scale. High resolution spectra with orders concatenated and low resolution spatially-resolved SILO images are stored in the Principal Centre server and its mirror. Requests for retrieval of high resolution spectra and SILO images are therefore resolved by the National Host server and passed to the Principal Centre server or mirror, from where the data are returned directly to the client.

All data products are delivered as FITS files, and can be imported into standard image processing packages such as IDL, IRAF and MIDAS.

Data Retrieval

In the HTML output format, links are provided which display the FITS header of each low resolution or rebinned spectrum, plot each spectrum, refer to publications which have used this spectrum and download individual spectra. Groups of spectra can be retrieved, with group selection defined according to file type, e.g. low dispersion, or fine-tuned by marking individual spectra. Multiple retrieval of high dispersion spectra can also be restricted to a specific wavelength interval. On-line descriptions of each output column and of data retrieval are available via embedded links in the output form.

Further Information

A detailed description of the Spacecraft, the IUE Final Archive and INES is given in the on-line project documentation, and it is recommended that you browse these articles for more information on the project. Should you have questions you are unable to resolve, or indeed suggestions as to how INES may be improved, a HelpDesk facility is available which is searchable by topic, and to which you may send your comments. Updated information about the INES Project can be found at the Principal Centre Home Page.

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Last update: Apr. 11, 2000.