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7.8 Using the ISO Data Archive

A short summary follows of the main features of the IDA User Interface. Extensive context-help is available directly for each field in the user interface and a guided tour can be accessed on the ISO Data Center web site at:

         https://www.cosmos.esa.int/web/iso $\rightarrow$ Guided Tour of the Archive         

Access the ISO Data Archive interface

Having reached the ISO Data Archive on the WWW (https://www.cosmos.esa.int/web/iso $\rightarrow$ Access the Archive) and having started the Java applet, users can define a query as shown in Figure 7.3.

Figure 7.3: ISO Data Archive main query panel.
\resizebox {15cm}{!}{\includegraphics*{ida61.eps}}

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:

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Target name (as given by the proposer or resolved via NED or SIMBAD)
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Coordinates
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Wavelength ranges
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Type of observing mode (AOT) used by the satellite
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Instrument

Other sub-panels are more specific and allow searches against parameters like:

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Highly Processed Data Products
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Observer or proposal name, proposal text, observation identifier
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Date, time, uplink software version, revolution or phase in orbit
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Target name list
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Observation list
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Raster map parameters
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Instrument specific details parameters

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: ISO Data Archive query results panel with associated browse products
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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:

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Target name
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Observing mode
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Coordinates
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Observation type and number
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Field of view
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Wavelength range
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Observer and proposal identification
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Date, time and observation length
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Data quality information

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:

  1. Data
    Data can be retrieved via direct download on disk.

  2. Documentation
    If it is a published article, a link is given to the corresponding abstract in ADS, otherwise, a link is provided to a documentation file stored in IDA.

  3. The button `Add related' will move all observations pertaining to the given HPDP set to the shopping basket for retrieval of all observations in one go.

    More buttons may be highlighted depending on the availability in the given HPDP set:

  4. Postcard
    An illustration (plot, image) of the reduced observation. This will be obtained by automatically launching your default browser.

  5. Atlas
    This is defined as illustration of the observations together with other information provided in the HPDP set, such as externally derived Spectral Energy Distributions, stellar models, etc.

  6. Catalogue
    A new panel will be launched, pointing to the observation specific information. The whole catalogue may be saved on disk or printed.

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.

Requesting the data

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.:

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Raw data
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Basic science
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Fully processed
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Quick-look
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Custom
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HPDP
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All

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]).


next up previous contents index
Next: 7.9 Historical Aspects Up: 7. The ISO Data Previous: 7.7 Interoperability Aspects
ISO Handbook Volume I (GEN), Version 2.0, SAI/2000-035/Dc