Vespa Bandeau

How To Use the VESPA Portal


    VESPA is an integrated system connecting many data services related to Planetary Science and solar Physics. The VESPA portal allows the user to query simultaneously these services, to identify data of interest from science-oriented parameters, and to plot and analyze data on-line using standard techniques.

  • Quick Start

      This section only provides a basic description of the interface. See next section for any question.

      The entry page is divided in 3 columns. The leftmost one is the query area, the central part is the result display area, the rightmost column provides links to external tools and help.

    • Modes
      On top of the query area (left column) are 4 fields highlighted in blue. In standard mode, the "Form" and "EPN-TAP services" buttons should be selected.

    • Query Form
      The leftmost column displays a form that allows the user to build his query. This consists in providing values to standard query fields. Each one acts as a filter which reduces the number of results; none is mandatory (no requested value = no filtering). Fields are grouped by thematic panels, with the "Main parameters" panel open by default.

      • Fields
        Info: Contextual help is displayed when hovering the mouse over the field name for 1s.
        Target Name: Start typing; a name resolver is available for field completion and disambiguation.
        Other field panels: Other field panels, as well as value lists, are open by clicking on their banner. Fields set in closed panels are included in the query (click the red "Reset" button if needed).

      • Send Query
        To send the query, click the blue "Submit" button at the bottom of the column.

    • Query Result
      The central area of the page display all connected services with the number of results - by default the number of information they contain.
      When submitting a query, the central area is rebuilt to display the number of matches in each connected service. Services containing results matching the query are displayed first, in green.
      Pick up your favorite service and click on its title to access detailed content.

    • Service Results
      When entering the service mode, the central area now displays a description of the service (green box) and a table of results described by several parameters. By default, only the top of the table is displayed with a selection of parameters. The set of buttons below the green box are used to set the table layout (number of lines and parameters). All parameters are displayed by clicking the "Show all" button. The table can be browsed using the buttons at the bottom right corner.
      The first line (above the green box) returns to the display of all services.
      The link under the service acronym (second line) redirects to the main web site of the service, if available.
      The left menu is still available to change or refine your query in the displayed service.

      • Mouse actions
        • Mouse over: When hovering the mouse over the table, a thumbnail may be displayed in real time (depending on service).
        • Selections: Individual results can be selected/unselected by simply clicking on table lines. "Select all" / "Reset" buttons are available on top of the table.

      • Data & metadata retrieval
        Information can be sent to open VO applications using the local menus at the bottom left of the table. Select line(s) of interest and click:
        • Data/Send [type]: Send data file(s) with specified data type - will only open in VO applications supporting this data type, e.g., images in Aladin (see "Plotting tools" menu). This menu is greyed out when the data are scalars values (included in the table itself).
        • Metadata/Send table: Send the description table to VO applications (in VOTable format, typically handled by TOPCAT).
        The two menus on the bottom right allow you to select one of the available targets, and to plot footprints if available:
        • Send GeoJSON: Opens Mizar and sends a rough footprint for 3D plot.
        • Send s_region: Send a more accurate s_region footprint to Aladin for 3D plot (you may want to load a HiPS map of the target first)



  • Detailed Interface Description

      The first page should present 3 vertical areas. If the interface looks weird, try and clear your browser's cache.
      VESPA layout

    • Query Form
      The leftmost column displays a form that allows the user to build his query. This consists in providing values to standard query fields. Each one acts as a filter which reduces the number of results; none is mandatory (no requested value = no filtering). Fields are grouped by thematic panels, with the "Main parameters" panel open by default.

      • Fields
        Info buttons: Contextual help is displayed when hovering the mouse over the field name for 1s. Definition and usage of EPN-TAP parameters is decribed here
        Multiple choice fields / lists: Fields presenting a list of values allow multiple selections; click on parameter name to show the list and check boxes as desired.
        Other field panels: Other field panels (Time, Location...) are opened by clicking on their banner. Fields set in closed panels are included in the query (click the red "Reset" button to make sure).
        Target Name: Accepts standard IAU names of solar system bodies (only one at a time). The SsODNet name resolver is used for field completion, disambiguation, and query extension. Two characters are required for completion; all known aliases of the target are included in the query; if a target_class is selected, only targets in this class will be proposed by the resolver and included in the query (both fields are required for disambiguation of bodies sharing the same name, e. g. Dione).
        Special parameters:
        "Spatial coordinates" (in Location panel): first select the Spatial frame type, which determines the nature of the coordinates; tags will adapt to the system in use. In body-fixed frame, longitudes range from 0° to 360° eastward (IAU convention).
        "Spectral range" (in Spectral panel): first select the unit (Hz or µm) to set the scale as frequency or wavelength, then enter range.
        "Granule and Obs IDs" (in Data reference panel) are service-specific and provide grouping in different types of products. Use these to restrain a search on a service you know in details.
        "Measurement type" (in Data reference panel) describe the physical quantities provided in the service, encoded as UCDs. An interactive resolver of IVOA UCDs is available here; a more complete list is available here (including new values defined for the Solar System); or have a look at a service of interest to see how your preferred value is encoded.
        "Optional parameters" are not available for all services; the values entered here are sent only to services which use them.

      • Send Query
        To send the query, click the blue "Submit" button at the bottom of the column.

    • Query modes
      On top of the query area (left column) are 2 sets of 2 buttons. In standard mode, the "Form" and "EPN-TAP services" buttons should be selected (default).
      • Form
        Standard form to query all registered services based on standard parameters (described above).

      • EPN-TAP Services
        Will send the query to all connected services (or to the displayed one in table result display).

      • Custom Service
        Opens a window allowing the user to query a single service. This mode is intended to access services not publicly open (i.e., installed on a TAP server but not declared in the registry). The form is the same as in "All VO" but starts with two extra fields:
        Resource URL: URL of a TAP server (e.g., http://DacHS_server.../tap - /tap is required!).
        Schema name: Name of the EPN-TAP schema to query (e.g., vvex, not vvex.epn_core)
        These two fields must be informed in Custom Service mode.
        This mode can also be used to bypass the query of all services if you want to work with a specific published service. In this case, just type the service schema name.
        Note: these fields are usually memorized by your browser and available for completion. To remove a memorized value, highlight it and press Shift-Delete.

      • Query
        The query menu is replaced by a free text field where advanced users to write a query directly in ADQL language. The Query mode only addresses the WHERE clause of the ADQL query. This mode can be combined with the Custom service mode to send a query to a single service.
        Beware that comparison operators write, e.g., >= for ≥
        This mode allows for powerful searches using the footprint provided in the s_region parameter, such as:
          INTERSECTS(s_region, POLYGON('UNKNOWNFrame', 150, 0, 150, 5, 190, 5, 190, 0))=1
          CONTAINS(s_region, POLYGON('UNKNOWNFrame', 150, 0, 150, 5, 190, 5, 190, 0))=1
        and searches of individual values in lists, such as:
          ivo_hashlist_has(lower(instrument_name), 'iks') = 1
        The latter function is supported at least by DaCHS servers (most of those used for EPN-TAP).
        To issue more sophisticated queries on a single service (or to non EPN-TAP services on a single server), TOPCAT and TapHandle may prove more flexible.

      • Advanced Query
        This mode is accessible from the Result page of an individual service.
        In the query area, all non-mandatory parameters present in the service are accessible in the "Other" panel with a scroll-down menu starting with "s_region". Click the "+" button to use several such parameters, "x" to remove one.


    • Query results

      • Service status
        • Green (with 3 icons): Results exist
        • Grey (with 2 icons): No result found
        • Red (with a single icon): Error (service not responding, or not supporting the query)

        The server answer is always available under the "Download VOtable" icon, even if the service is in error. In this case it provides a diagnosis of possible issues, as per TAP protocol requirements.

      • Resource details
        A short description of each service is available by clicking the rightmost icon.

      • Service actions
        Several actions are possible on services providing results:
        • Display Results: Clicking the name of the service displays a table of all results in this service for further examination.
        • Send with SAMP: Will send the metadata VOTable to another VO application using the SAMP protocol (typically TOPCAT).
          If no SAMP compatible application is open, the TOPCAT webstart will be downloaded. Links to common VO applications are available in the "Plotting tools" menu on the right side of the page.
        • Download VOTable: Load the metadata VOTable on your computer (possibly including an error message from the server).

      • Other data services
        The user's EPN-TAP query is also converted and forwarded to other data services, so as to help discovery in other data distribution systems. Links appear in separated boxes below the list of EPN-TAP services.
        First, the query is sent to PDAP servers located at ESA (PSA) and JAXA (DARTS). PDAP is mainly used to mirror archives between space agencies. Due to the current specifications of the PDAP protocol, queries are limited to dataset level (DARTS also requires a target_name value to return results). PDAP results can be downloaded as a VOtable from the portal.
        Second, the query is converted to fit the NASA PDS catalogue service, again at dataset level. The link provided in the portal leads to a NASA page listing matches in both NASA and ESA archives. This page starts with a list of links grouped in various categories (agency, mission, instrument, etc).

    • Service Results
      This page displays a table containing the service results with basic description; the number of results per page can be selected in the "Show entries" menu. Extra parameters can be selected in the "Column visibility" and with the "Show all" buttons.
      The link under the service acronym (second line) redirects to the main web site of the service, if available.
      The left menu is still available to change or refine your query in the displayed service.

      • Mouse actions
        • Mouse over: When hovering the mouse over the table, a thumbnail may be displayed in real time (depending on service).
        • Access_url field: Clicking the link will load the data file (will be downloaded if not plottable in a browser).
        • Selections: Individual results can be selected/unselected by simply clicking on table lines.
        • Sorting: Lines are sorted according to a parameter when clicking on the column headers.
        • Unit: Spectral scale can be displayed as frequency (in Hz) or wavelength (in µm) by clicking the unit in the header - spectral resolution and step are currently only available as frequency.

      • Data & metadata retrieval
        Information can be sent to open VO applications using the local menus at the bottom of the list. If required, the preferred VO application will be downloaded on your machine (as java webstart) - alternatively you can run an existing local version to save time; links to common VO applications are also available in the "Plotting tools" menu (rightmost area of the page). Four menus are available to process data (files provided under access_url) or metadata (the table content), either for the whole table or the currently selected lines.
        • Data/Download: Will download the data file on your computer for manual use (multiple entries are zipped). This menu and the next one are greyed out when the data are scalars included in the table itself.
        • Data/Send [type]: Send data file(s) with specified data type - will only open in VO applications supporting this data type, e.g., images in Aladin (see "Plotting tools" menu).
          Special types include CDF (sent to TOPCAT) and Virtis PDS spectral cubes (opens APERICubes for display and converts to fits - you still have to click on the "Process Samp Cube" button to see it)
        • Metadata/Download: Will download the metadata file on your computer as VOTable for manual use (multiple entries are merged - same as the corresponding icon on the Query result page).
        • Metadata/Send table: Send description table(s) to open VO applications (in VOTable format; this is typically handled by TOPCAT - same as the corresponding icon on the Query result page).
        The two menus on the bottom right allow you to visualize data footprints:
        • Target: List the targets present in the service
        • Send GeoJSON (all/selection): Open Mizar and display bounding box(es) on a 3D plot of the target - available if fields C1/2 min/max are provided in body-fixed frame.
        • Send s_region: Open Aladin and display selected footprint(s) on a 3D plot - available if field s_region is provided (you may want to load a HiPS map of the target in Aladin first)

      If you need to retrieve an ascii version of data provided as VOtable (e.g., Titan profiles service), first check if the service provides granules in ascii format. Otherwise, send as Table to TOPCAT and save it in ascii from there (this can be scripted for pipeline processing).
      In case the data are not sent to the support application (webstart reloaded continously), try and deactivate any proxy in your browser.
      Direct solutions exist to load data in IDL/GDL, in particular for PDS3 files and VOTables. Queries are also possible from python.


  • Alternative accesses
  • EPN-TAP data services can be accessed in various ways, indications here

  • Tutorials
  • EPN-TAP services and VESPA interface: Imaging spectrometry demo (Virtis/VEx EPN-TAP service)
    EPN-TAP services and VESPA interface: Searching and plotting atmospheric profiles (Titan/CIRS service)

  • Links
    Europlanet2020 / VESPA site

  • Credits
  • The SsODNet name resolver is provided by IMCCE/Observatoire de Paris
    Mizar is a plugin for SItools2 provided by J.-C. Malapert, CNES
    APERICubes is developed by R. Savale, Observatoire de Paris
    Other VO applications are maintained by their respective developers
    The Europlanet 2020 Research Infrastructure project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 654208.

Plotting tools

Example queries

Help