http://www.iso.vilspa.esa.es/ 
Guided Tour of the Archive
Access the ISO Data Archive interface
Having reached the ISO Data Archive on the WWW
(http://www.iso.vilspa.esa.es/ Access the Archive)
and having started the Java applet, users can define a query as shown in
Figure 7.3.
The Main query panel consists of various subpanels, which can be opened to specify parameters against which to query.
The Principal search criteria panel, opened by default, allows the general astronomer to query against general parameters such as:
Other sub-panels are more specific and allow searches against parameters like:
Aimed more at expert users, the interface supports querying of non-standard modes, including engineering data and additional observations obtained in parallel to other instruments or while slewing between targets.
Once the user has completed the search criteria, the query can be executed. The query can also be manually edited to allow expert users to perform more complex queries which are not possible through entering values in search boxes (see Appendix G).
Getting the results
Once a query has been executed, the archive returns the list of observations matching the constraints in the Latest Results panel. A subset -- sized to fit on the screen -- of the returned list of observations will be displayed. The user can scroll through this list using navigational buttons.
Figure 7.4 shows an example of the information
displayed for each observation.
An icon (one of the browse products) on the right-hand
side of the screen gives an immediate visual impression of the data
content of the observation. The postcard can be viewed by clicking on
the icon. A Survey Products Display
Tool (SPDT)
allows simple manipulation of the FITS survey
products. The amount of information and observations displayed
in the Latest Results
panel can be customised; the main parameters are:
Highly Processed Data Products
The Highly Processed Data Products (HPDPs) are a different kind of products, well distinguished from the homogeneous set of pipeline products. A specific interface has been designed to display and retrieve them in a uniform way. For observations in the Latest Results panel having associated HPDPs, a number of options are given to access relevant information and data. A dedicated panel gives the abstracts of all HPDP sets associated to the observation. The following options are given as applicable:
More buttons may be highlighted depending on the availability in the given HPDP set:
Observational Details and Related Products
Many additional data products are connected directly to
individual observations, but not retrievable in the same
way as the observational data (e.g. uplink files and
downlink, real-time and instrument reports, proposal abstracts).
These products are available
under the `Details' and `Related' buttons in the archive
and can be saved directly into a file.
Another innovative and friendly feature of the ISO Data Archive is the wide selection of possibilities offered for the retrieval of data. Once a query has been performed and the user has logged in, observations can be selected for retrieval by moving them to the `shopping basket'. The user can then perform other queries, select other observations and add them to the shopping basket. The Shopping Basket panel looks very similar to the Latest Results one and is similarly configurable. For all observations in the shopping basket, the user can select the level of products to be retrieved, i.e.:
These choices can be made for all observations as well as per observation and they can be combined. Moreover, through the custom option, users can choose their own set of files to be retrieved.
Once ready for requesting the data, users can press the `Submit
Request' button. The User Interface then determines the volume of
data, checks whether the daily quota for the user has been exceeded
and asks the user for a compression format. The download time by
ftp (default means of data retrieval) can be estimated if required.
The archive processes the data retrieval task and copies the data into an
ftp public area, where it is stored for a period of
seven days. The user is informed by e-mail when and where data is
available.
A direct retrieval on disk is also possible for each observation
in the Latest Results query panel.
User registration and login
Anybody can query the archive and see results and associated
quick-look data. However, before being able to retrieve observations,
a username and a password has to be requested and issued. This login
mechanism was necessary to protect proprietary data during and
shortly after the mission. It also helps in monitoring archive usage
and avoids possible disturbances from hackers. Additionally, users
have to provide their e-mail address to receive notifications from
the archive, when their product report is completed.
The user database is also used to maintain close contact with the
users community (Matagne 2002, [119]).
Advanced user access the ISO Data Archive database
A specific java applet allows a direct access to the ISO Data Archive metadata via an SQL-applet. The SQL interface allows expert users to perform searches against all queriable contents of the ISO Data Archive, including observation data products, auxiliary data, trend and housekeeping information and many other products. An on-line tutorial is available in the ISO Web site. Worked examples can be found in Appendix G.
Expert users can also create User Defined Functions to extract virtual attributes from files external to the database engine. These virtual attributes can then further be used in queries inside the database engine (Wieprecht et al. 1999, [165]).
